Merge tag 'xfs-4.15-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
"xfs: great scads of new stuff for 4.15.

This merge cycle, we're making some substantive changes to XFS. The
in-core extent mappings have been refactored to use proper iterators
and a btree to handle heavily fragmented files without needing
high-order memory allocations; some important log recovery bug fixes;
and the first part of the online fsck functionality.

(The online fsck feature is disabled by default and more pieces of it
will be coming in future release cycles.)

This giant pile of patches has been run through a full xfstests run
over the weekend and through a quick xfstests run against this
morning's master, with no major failures reported.

New in this version:

- Refactor the incore extent map manipulations to use a cursor
instead of directly modifying extent data.

- Refactor the incore extent map cursor to use an in-memory btree
instead of a single high-order allocation. This eliminates a major
source of complaints about insufficient memory when opening a
heavily fragmented file into a system whose memory is also heavily
fragmented.

- Fix a longstanding bug where deleting a file with a complex
extended attribute btree incorrectly handled memory pointers, which
could lead to memory corruption.

- Improve metadata validation to eliminate crashing problems found
while fuzzing xfs.

- Move the error injection tag definitions into libxfs to be shared
with userspace components.

- Fix some log recovery bugs where we'd underflow log block position
vector and incorrectly fail log recovery.

- Drain the buffer lru after log recovery to force recovered buffers
back through the verifiers after mount. On a v4 filesystem the log
never attaches verifiers during log replay (v5 does), so we could
end up with buffers marked verified but without having ever been
verified.

- Fix various other bugs.

- Introduce the first part of a new online fsck tool. The new fsck
tool will be able to iterate every piece of metadata in the
filesystem to look for obvious errors and corruptions. In the next
release cycle the checking will be extended to cross-reference with
the other fs metadata, so this feature should only be used by the
developers in the mean time"

* tag 'xfs-4.15-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (131 commits)
xfs: on failed mount, force-reclaim inodes after unmounting quota controls
xfs: check the uniqueness of the AGFL entries
xfs: remove u_int* type usage
xfs: handle zero entries case in xfs_iext_rebalance_leaf
xfs: add comments documenting the rebalance algorithm
xfs: trivial indentation fixup for xfs_iext_remove_node
xfs: remove a superflous assignment in xfs_iext_remove_node
xfs: add some comments to xfs_iext_insert/xfs_iext_insert_node
xfs: fix number of records handling in xfs_iext_split_leaf
fs/xfs: Remove NULL check before kmem_cache_destroy
xfs: only check da node header padding on v5 filesystems
xfs: fix btree scrub deref check
xfs: fix uninitialized return values in scrub code
xfs: pass inode number to xfs_scrub_ino_set_{preen,warning}
xfs: refactor the directory data block bestfree checks
xfs: mark xlog_verify_dest_ptr STATIC
xfs: mark xlog_recover_check_summary STATIC
xfs: mark xfs_btree_check_lblock and xfs_btree_check_ptr static
xfs: remove unreachable error injection code in xfs_qm_dqget
xfs: remove unused debug counts for xfs_lock_inodes
...

fs/xfs/Kconfig

···
 
 	  If unsure, say N.
 
+config XFS_ONLINE_SCRUB
+	bool "XFS online metadata check support"
+	default n
+	depends on XFS_FS
+	help
+	  If you say Y here you will be able to check metadata on a
+	  mounted XFS filesystem.  This feature is intended to reduce
+	  filesystem downtime by supplementing xfs_repair.  The key
+	  advantage here is to look for problems proactively so that
+	  they can be dealt with in a controlled manner.
+
+	  This feature is considered EXPERIMENTAL.  Use with caution!
+
+	  See the xfs_scrub man page in section 8 for additional information.
+
+	  If unsure, say N.
+
 config XFS_WARN
 	bool "XFS Verbose Warnings"
 	depends on XFS_FS && !XFS_DEBUG

fs/xfs/Makefile

···
 				   xfs_dquot_buf.o \
 				   xfs_ialloc.o \
 				   xfs_ialloc_btree.o \
+				   xfs_iext_tree.o \
 				   xfs_inode_fork.o \
 				   xfs_inode_buf.o \
 				   xfs_log_rlimit.o \
···
 xfs-$(CONFIG_SYSCTL)		+= xfs_sysctl.o
 xfs-$(CONFIG_COMPAT)		+= xfs_ioctl32.o
 xfs-$(CONFIG_EXPORTFS_BLOCK_OPS)	+= xfs_pnfs.o
+
+# online scrub/repair
+ifeq ($(CONFIG_XFS_ONLINE_SCRUB),y)
+
+# Tracepoints like to blow up, so build that before everything else
+
+xfs-y				+= $(addprefix scrub/, \
+				   trace.o \
+				   agheader.o \
+				   alloc.o \
+				   attr.o \
+				   bmap.o \
+				   btree.o \
+				   common.o \
+				   dabtree.o \
+				   dir.o \
+				   ialloc.o \
+				   inode.o \
+				   parent.o \
+				   refcount.o \
+				   rmap.o \
+				   scrub.o \
+				   symlink.o \
+				   )
+
+xfs-$(CONFIG_XFS_RT)		+= scrub/rtbitmap.o
+xfs-$(CONFIG_XFS_QUOTA)		+= scrub/quota.o
+endif

fs/xfs/kmem.h

···
 static inline void
 kmem_zone_destroy(kmem_zone_t *zone)
 {
-	if (zone)
-		kmem_cache_destroy(zone);
+	kmem_cache_destroy(zone);
 }
 
 extern void *kmem_zone_alloc(kmem_zone_t *, xfs_km_flags_t);

fs/xfs/libxfs/xfs_ag_resv.c

···
 #include "xfs_mount.h"
 #include "xfs_defer.h"
 #include "xfs_alloc.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
 #include "xfs_cksum.h"

fs/xfs/libxfs/xfs_alloc.c

···
 #include "xfs_alloc_btree.h"
 #include "xfs_alloc.h"
 #include "xfs_extent_busy.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_cksum.h"
 #include "xfs_trace.h"
···
 	query.priv = priv;
 	query.fn = fn;
 	return xfs_btree_query_all(cur, xfs_alloc_query_range_helper, &query);
+}
+
+/* Find the size of the AG, in blocks. */
+xfs_agblock_t
+xfs_ag_block_count(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno)
+{
+	ASSERT(agno < mp->m_sb.sb_agcount);
+
+	if (agno < mp->m_sb.sb_agcount - 1)
+		return mp->m_sb.sb_agblocks;
+	return mp->m_sb.sb_dblocks - (agno * mp->m_sb.sb_agblocks);
+}
+
+/*
+ * Verify that an AG block number pointer neither points outside the AG
+ * nor points at static metadata.
+ */
+bool
+xfs_verify_agbno(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		agbno)
+{
+	xfs_agblock_t		eoag;
+
+	eoag = xfs_ag_block_count(mp, agno);
+	if (agbno >= eoag)
+		return false;
+	if (agbno <= XFS_AGFL_BLOCK(mp))
+		return false;
+	return true;
+}
+
+/*
+ * Verify that an FS block number pointer neither points outside the
+ * filesystem nor points at static AG metadata.
+ */
+bool
+xfs_verify_fsbno(
+	struct xfs_mount	*mp,
+	xfs_fsblock_t		fsbno)
+{
+	xfs_agnumber_t		agno = XFS_FSB_TO_AGNO(mp, fsbno);
+
+	if (agno >= mp->m_sb.sb_agcount)
+		return false;
+	return xfs_verify_agbno(mp, agno, XFS_FSB_TO_AGBNO(mp, fsbno));
 }

fs/xfs/libxfs/xfs_alloc.h

···
 		xfs_alloc_query_range_fn fn, void *priv);
 int xfs_alloc_query_all(struct xfs_btree_cur *cur, xfs_alloc_query_range_fn fn,
 		void *priv);
+xfs_agblock_t xfs_ag_block_count(struct xfs_mount *mp, xfs_agnumber_t agno);
+bool xfs_verify_agbno(struct xfs_mount *mp, xfs_agnumber_t agno,
+		xfs_agblock_t agbno);
+bool xfs_verify_fsbno(struct xfs_mount *mp, xfs_fsblock_t fsbno);
 
 #endif	/* __XFS_ALLOC_H__ */

fs/xfs/libxfs/xfs_attr_leaf.c

···
 	/* rounded down */
 	offset = (XFS_LITINO(mp, dp->i_d.di_version) - bytes) >> 3;
 
-	switch (dp->i_d.di_format) {
-	case XFS_DINODE_FMT_DEV:
+	if (dp->i_d.di_format == XFS_DINODE_FMT_DEV) {
 		minforkoff = roundup(sizeof(xfs_dev_t), 8) >> 3;
-		return (offset >= minforkoff) ? minforkoff : 0;
-	case XFS_DINODE_FMT_UUID:
-		minforkoff = roundup(sizeof(uuid_t), 8) >> 3;
 		return (offset >= minforkoff) ? minforkoff : 0;
 	}
 

fs/xfs/libxfs/xfs_bmap.c

···
 #include "xfs_bmap_util.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_rtalloc.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_quota.h"
 #include "xfs_trans_space.h"
···
 STATIC int				/* error */
 xfs_bmbt_lookup_eq(
 	struct xfs_btree_cur	*cur,
-	xfs_fileoff_t		off,
-	xfs_fsblock_t		bno,
-	xfs_filblks_t		len,
+	struct xfs_bmbt_irec	*irec,
 	int			*stat)	/* success/failure */
 {
-	cur->bc_rec.b.br_startoff = off;
-	cur->bc_rec.b.br_startblock = bno;
-	cur->bc_rec.b.br_blockcount = len;
+	cur->bc_rec.b = *irec;
 	return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
 }
 
 STATIC int				/* error */
-xfs_bmbt_lookup_ge(
+xfs_bmbt_lookup_first(
 	struct xfs_btree_cur	*cur,
-	xfs_fileoff_t		off,
-	xfs_fsblock_t		bno,
-	xfs_filblks_t		len,
 	int			*stat)	/* success/failure */
 {
-	cur->bc_rec.b.br_startoff = off;
-	cur->bc_rec.b.br_startblock = bno;
-	cur->bc_rec.b.br_blockcount = len;
+	cur->bc_rec.b.br_startoff = 0;
+	cur->bc_rec.b.br_startblock = 0;
+	cur->bc_rec.b.br_blockcount = 0;
 	return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
 }
 
···
 }
 
 /*
- * Update the record referred to by cur to the value given
- * by [off, bno, len, state].
+ * Update the record referred to by cur to the value given by irec
  * This either works (return 0) or gets an EFSCORRUPTED error.
  */
 STATIC int
 xfs_bmbt_update(
 	struct xfs_btree_cur	*cur,
-	xfs_fileoff_t		off,
-	xfs_fsblock_t		bno,
-	xfs_filblks_t		len,
-	xfs_exntst_t		state)
+	struct xfs_bmbt_irec	*irec)
 {
 	union xfs_btree_rec	rec;
 
-	xfs_bmbt_disk_set_allf(&rec.bmbt, off, bno, len, state);
+	xfs_bmbt_disk_set_all(&rec.bmbt, irec);
 	return xfs_btree_update(cur, &rec);
 }
 
···
 {
 	if (whichfork == XFS_ATTR_FORK &&
 	    ip->i_d.di_format != XFS_DINODE_FMT_DEV &&
-	    ip->i_d.di_format != XFS_DINODE_FMT_UUID &&
 	    ip->i_d.di_format != XFS_DINODE_FMT_BTREE) {
 		uint	dfl_forkoff = xfs_default_attroffset(ip) >> 3;
 
···
 }
 
 /*
- * Add bmap trace insert entries for all the contents of the extent records.
- */
-void
-xfs_bmap_trace_exlist(
-	xfs_inode_t	*ip,		/* incore inode pointer */
-	xfs_extnum_t	cnt,		/* count of entries in the list */
-	int		whichfork,	/* data or attr or cow fork */
-	unsigned long	caller_ip)
-{
-	xfs_extnum_t	idx;		/* extent record index */
-	xfs_ifork_t	*ifp;		/* inode fork pointer */
-	int		state = 0;
-
-	if (whichfork == XFS_ATTR_FORK)
-		state |= BMAP_ATTRFORK;
-	else if (whichfork == XFS_COW_FORK)
-		state |= BMAP_COWFORK;
-
-	ifp = XFS_IFORK_PTR(ip, whichfork);
-	ASSERT(cnt == xfs_iext_count(ifp));
-	for (idx = 0; idx < cnt; idx++)
-		trace_xfs_extlist(ip, idx, state, caller_ip);
-}
-
-/*
  * Validate that the bmbt_irecs being returned from bmapi are valid
  * given the caller's original parameters.  Specifically check the
  * ranges of the returned irecs to ensure that they only extend beyond
···
 	cbno = be64_to_cpu(*pp);
 	*logflagsp = 0;
 #ifdef DEBUG
-	if ((error = xfs_btree_check_lptr(cur, cbno, 1)))
-		return error;
+	XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
+			xfs_btree_check_lptr(cur, cbno, 1));
 #endif
 	error = xfs_btree_read_bufl(mp, tp, cbno, 0, &cbp, XFS_BMAP_BTREE_REF,
 				&xfs_bmbt_buf_ops);
···
 	xfs_bmbt_rec_t		*arp;		/* child record pointer */
 	struct xfs_btree_block	*block;		/* btree root block */
 	xfs_btree_cur_t		*cur;		/* bmap btree cursor */
-	xfs_bmbt_rec_host_t	*ep;		/* extent record pointer */
 	int			error;		/* error return value */
-	xfs_extnum_t		i, cnt;		/* extent record index */
 	xfs_ifork_t		*ifp;		/* inode fork pointer */
 	xfs_bmbt_key_t		*kp;		/* root block key pointer */
 	xfs_mount_t		*mp;		/* mount structure */
-	xfs_extnum_t		nextents;	/* number of file extents */
 	xfs_bmbt_ptr_t		*pp;		/* root block address pointer */
+	struct xfs_iext_cursor	icur;
+	struct xfs_bmbt_irec	rec;
+	xfs_extnum_t		cnt = 0;
 
 	mp = ip->i_mount;
 	ASSERT(whichfork != XFS_COW_FORK);
···
 				XFS_BTNUM_BMAP, 0, 0, ip->i_ino,
 				XFS_BTREE_LONG_PTRS);
 
-	arp = XFS_BMBT_REC_ADDR(mp, ablock, 1);
-	nextents =  xfs_iext_count(ifp);
-	for (cnt = i = 0; i < nextents; i++) {
-		ep = xfs_iext_get_ext(ifp, i);
-		if (!isnullstartblock(xfs_bmbt_get_startblock(ep))) {
-			arp->l0 = cpu_to_be64(ep->l0);
-			arp->l1 = cpu_to_be64(ep->l1);
-			arp++; cnt++;
-		}
+	for_each_xfs_iext(ifp, &icur, &rec) {
+		if (isnullstartblock(rec.br_startblock))
+			continue;
+		arp = XFS_BMBT_REC_ADDR(mp, ablock, 1 + cnt);
+		xfs_bmbt_disk_set_all(arp, &rec);
+		cnt++;
 	}
 	ASSERT(cnt == XFS_IFORK_NEXTENTS(ip, whichfork));
 	xfs_btree_set_numrecs(ablock, cnt);
···
 	xfs_bmap_forkoff_reset(ip, whichfork);
 	ifp->if_flags &= ~XFS_IFINLINE;
 	ifp->if_flags |= XFS_IFEXTENTS;
+	ifp->if_u1.if_root = NULL;
+	ifp->if_height = 0;
 	XFS_IFORK_FMT_SET(ip, whichfork, XFS_DINODE_FMT_EXTENTS);
 }
 
···
 	xfs_alloc_arg_t	args;		/* allocation arguments */
 	xfs_buf_t	*bp;		/* buffer for extent block */
 	struct xfs_bmbt_irec rec;
+	struct xfs_iext_cursor icur;
 
 	/*
 	 * We don't want to deal with the case of keeping inode data inline yet.
···
 
 	flags = 0;
 	error = 0;
-	ASSERT((ifp->if_flags & (XFS_IFINLINE|XFS_IFEXTENTS|XFS_IFEXTIREC)) ==
-								XFS_IFINLINE);
+	ASSERT((ifp->if_flags & (XFS_IFINLINE|XFS_IFEXTENTS)) == XFS_IFINLINE);
 	memset(&args, 0, sizeof(args));
 	args.tp = tp;
 	args.mp = ip->i_mount;
···
 	xfs_bmap_local_to_extents_empty(ip, whichfork);
 	flags |= XFS_ILOG_CORE;
 
+	ifp->if_u1.if_root = NULL;
+	ifp->if_height = 0;
+
 	rec.br_startoff = 0;
 	rec.br_startblock = args.fsbno;
 	rec.br_blockcount = 1;
 	rec.br_state = XFS_EXT_NORM;
-	xfs_iext_insert(ip, 0, 1, &rec, 0);
+	xfs_iext_first(ifp, &icur);
+	xfs_iext_insert(ip, &icur, &rec, 0);
 
-	trace_xfs_bmap_post_update(ip, 0,
-			whichfork == XFS_ATTR_FORK ? BMAP_ATTRFORK : 0,
-			_THIS_IP_);
 	XFS_IFORK_NEXT_SET(ip, whichfork, 1);
 	ip->i_d.di_nblocks = 1;
 	xfs_trans_mod_dquot_byino(tp, ip,
···
 		cur = xfs_bmbt_init_cursor(mp, tp, ip, XFS_DATA_FORK);
 		cur->bc_private.b.dfops = dfops;
 		cur->bc_private.b.firstblock = *firstblock;
-		if ((error = xfs_bmbt_lookup_ge(cur, 0, 0, 0, &stat)))
+		error = xfs_bmbt_lookup_first(cur, &stat);
+		if (error)
 			goto error0;
 		/* must be at least one entry */
 		XFS_WANT_CORRUPTED_GOTO(mp, stat == 1, error0);
···
 	case XFS_DINODE_FMT_DEV:
 		ip->i_d.di_forkoff = roundup(sizeof(xfs_dev_t), 8) >> 3;
 		break;
-	case XFS_DINODE_FMT_UUID:
-		ip->i_d.di_forkoff = roundup(sizeof(uuid_t), 8) >> 3;
-		break;
 	case XFS_DINODE_FMT_LOCAL:
 	case XFS_DINODE_FMT_EXTENTS:
 	case XFS_DINODE_FMT_BTREE:
···
  */
 
 /*
- * Read in the extents to if_extents.
- * All inode fields are set up by caller, we just traverse the btree
- * and copy the records in. If the file system cannot contain unwritten
- * extents, the records are checked for no "state" flags.
+ * Read in extents from a btree-format inode.
  */
-int					/* error */
-xfs_bmap_read_extents(
-	xfs_trans_t		*tp,	/* transaction pointer */
-	xfs_inode_t		*ip,	/* incore inode */
-	int			whichfork) /* data or attr fork */
+int
+xfs_iread_extents(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	int			whichfork)
 {
-	struct xfs_btree_block	*block;	/* current btree block */
-	xfs_fsblock_t		bno;	/* block # of "block" */
-	xfs_buf_t		*bp;	/* buffer for "block" */
-	int			error;	/* error return value */
-	xfs_extnum_t		i, j;	/* index into the extents list */
-	xfs_ifork_t		*ifp;	/* fork structure */
-	int			level;	/* btree level, for checking */
-	xfs_mount_t		*mp;	/* file system mount structure */
-	__be64			*pp;	/* pointer to block address */
-	/* REFERENCED */
-	xfs_extnum_t		room;	/* number of entries there's room for */
+	struct xfs_mount	*mp = ip->i_mount;
+	int			state = xfs_bmap_fork_to_state(whichfork);
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	xfs_extnum_t		nextents = XFS_IFORK_NEXTENTS(ip, whichfork);
+	struct xfs_btree_block	*block = ifp->if_broot;
+	struct xfs_iext_cursor	icur;
+	struct xfs_bmbt_irec	new;
+	xfs_fsblock_t		bno;
+	struct xfs_buf		*bp;
+	xfs_extnum_t		i, j;
+	int			level;
+	__be64			*pp;
+	int			error;
 
-	mp = ip->i_mount;
-	ifp = XFS_IFORK_PTR(ip, whichfork);
-	block = ifp->if_broot;
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	if (unlikely(XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)) {
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
+		return -EFSCORRUPTED;
+	}
+
 	/*
 	 * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
 	 */
···
 		error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
 				XFS_BMAP_BTREE_REF, &xfs_bmbt_buf_ops);
 		if (error)
-			return error;
+			goto out;
 		block = XFS_BUF_TO_BLOCK(bp);
 		if (level == 0)
 			break;
 		pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
 		bno = be64_to_cpu(*pp);
 		XFS_WANT_CORRUPTED_GOTO(mp,
-			XFS_FSB_SANITY_CHECK(mp, bno), error0);
+			XFS_FSB_SANITY_CHECK(mp, bno), out_brelse);
 		xfs_trans_brelse(tp, bp);
 	}
+
 	/*
 	 * Here with bp and block set to the leftmost leaf node in the tree.
 	 */
-	room = xfs_iext_count(ifp);
 	i = 0;
+	xfs_iext_first(ifp, &icur);
+
 	/*
 	 * Loop over all leaf nodes.  Copy information to the extent records.
 	 */
···
 		xfs_extnum_t	num_recs;
 
 		num_recs = xfs_btree_get_numrecs(block);
-		if (unlikely(i + num_recs > room)) {
-			ASSERT(i + num_recs <= room);
+		if (unlikely(i + num_recs > nextents)) {
+			ASSERT(i + num_recs <= nextents);
 			xfs_warn(ip->i_mount,
 				"corrupt dinode %Lu, (btree extents).",
 				(unsigned long long) ip->i_ino);
-			XFS_CORRUPTION_ERROR("xfs_bmap_read_extents(1)",
+			XFS_CORRUPTION_ERROR(__func__,
 				XFS_ERRLEVEL_LOW, ip->i_mount, block);
-			goto error0;
+			error = -EFSCORRUPTED;
+			goto out_brelse;
 		}
 		/*
 		 * Read-ahead the next leaf block, if any.
···
 		 * Copy records into the extent records.
 		 */
 		frp = XFS_BMBT_REC_ADDR(mp, block, 1);
-		for (j = 0; j < num_recs; j++, i++, frp++) {
-			xfs_bmbt_rec_host_t *trp = xfs_iext_get_ext(ifp, i);
-			trp->l0 = be64_to_cpu(frp->l0);
-			trp->l1 = be64_to_cpu(frp->l1);
-			if (!xfs_bmbt_validate_extent(mp, whichfork, trp)) {
+		for (j = 0; j < num_recs; j++, frp++, i++) {
+			xfs_bmbt_disk_get_all(frp, &new);
+			if (!xfs_bmbt_validate_extent(mp, whichfork, &new)) {
 				XFS_ERROR_REPORT("xfs_bmap_read_extents(2)",
 						 XFS_ERRLEVEL_LOW, mp);
-				goto error0;
+				error = -EFSCORRUPTED;
+				goto out_brelse;
 			}
+			xfs_iext_insert(ip, &icur, &new, state);
+			trace_xfs_read_extent(ip, &icur, state, _THIS_IP_);
+			xfs_iext_next(ifp, &icur);
 		}
 		xfs_trans_brelse(tp, bp);
 		bno = nextbno;
···
 		error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
 				XFS_BMAP_BTREE_REF, &xfs_bmbt_buf_ops);
 		if (error)
-			return error;
+			goto out;
 		block = XFS_BUF_TO_BLOCK(bp);
 	}
-	if (i != XFS_IFORK_NEXTENTS(ip, whichfork))
-		return -EFSCORRUPTED;
+
+	if (i != XFS_IFORK_NEXTENTS(ip, whichfork)) {
+		error = -EFSCORRUPTED;
+		goto out;
+	}
 	ASSERT(i == xfs_iext_count(ifp));
-	XFS_BMAP_TRACE_EXLIST(ip, i, whichfork);
+
+	ifp->if_flags |= XFS_IFEXTENTS;
 	return 0;
-error0:
+
+out_brelse:
 	xfs_trans_brelse(tp, bp);
-	return -EFSCORRUPTED;
+out:
+	xfs_iext_destroy(ifp);
+	return error;
 }
 
 /*
- * Returns the file-relative block number of the first unused block(s)
- * in the file with at least "len" logically contiguous blocks free.
- * This is the lowest-address hole if the file has holes, else the first block
- * past the end of file.
- * Return 0 if the file is currently local (in-inode).
+ * Returns the relative block number of the first unused block(s) in the given
+ * fork with at least "len" logically contiguous blocks free.  This is the
+ * lowest-address hole if the fork has holes, else the first block past the end
+ * of fork.  Return 0 if the fork is currently local (in-inode).
  */
 int						/* error */
 xfs_bmap_first_unused(
-	xfs_trans_t	*tp,			/* transaction pointer */
-	xfs_inode_t	*ip,			/* incore inode */
-	xfs_extlen_t	len,			/* size of hole to find */
-	xfs_fileoff_t	*first_unused,		/* unused block */
-	int		whichfork)		/* data or attr fork */
+	struct xfs_trans	*tp,		/* transaction pointer */
+	struct xfs_inode	*ip,		/* incore inode */
+	xfs_extlen_t		len,		/* size of hole to find */
+	xfs_fileoff_t		*first_unused,	/* unused block */
+	int			whichfork)	/* data or attr fork */
 {
-	int		error;			/* error return value */
-	int		idx;			/* extent record index */
-	xfs_ifork_t	*ifp;			/* inode fork pointer */
-	xfs_fileoff_t	lastaddr;		/* last block number seen */
-	xfs_fileoff_t	lowest;			/* lowest useful block */
-	xfs_fileoff_t	max;			/* starting useful block */
-	xfs_extnum_t	nextents;		/* number of extent entries */
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	struct xfs_bmbt_irec	got;
+	struct xfs_iext_cursor	icur;
+	xfs_fileoff_t		lastaddr = 0;
+	xfs_fileoff_t		lowest, max;
+	int			error;
 
 	ASSERT(XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE ||
 	       XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS ||
 	       XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL);
+
 	if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
 		*first_unused = 0;
 		return 0;
 	}
-	ifp = XFS_IFORK_PTR(ip, whichfork);
-	if (!(ifp->if_flags & XFS_IFEXTENTS) &&
-	    (error = xfs_iread_extents(tp, ip, whichfork)))
-		return error;
-	lowest = *first_unused;
-	nextents = xfs_iext_count(ifp);
-	for (idx = 0, lastaddr = 0, max = lowest; idx < nextents; idx++) {
-		struct xfs_bmbt_irec got;
 
-		xfs_iext_get_extent(ifp, idx, &got);
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		error = xfs_iread_extents(tp, ip, whichfork);
+		if (error)
+			return error;
+	}
 
+	lowest = max = *first_unused;
+	for_each_xfs_iext(ifp, &icur, &got) {
 		/*
 		 * See if the hole before this extent will work.
 		 */
 		if (got.br_startoff >= lowest + len &&
-		    got.br_startoff - max >= len) {
-			*first_unused = max;
-			return 0;
-		}
+		    got.br_startoff - max >= len)
+			break;
 		lastaddr = got.br_startoff + got.br_blockcount;
 		max = XFS_FILEOFF_MAX(lastaddr, lowest);
 	}
+
 	*first_unused = max;
 	return 0;
 }
···
 {
 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
 	struct xfs_bmbt_irec	got;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	icur;
 	int			error;
 
 	switch (XFS_IFORK_FORMAT(ip, whichfork)) {
···
 			return error;
 	}
 
-	if (xfs_iext_lookup_extent(ip, ifp, *last_block - 1, &idx, &got)) {
-		if (got.br_startoff <= *last_block - 1)
-			return 0;
-	}
-
-	if (xfs_iext_get_extent(ifp, idx - 1, &got)) {
-		*last_block = got.br_startoff + got.br_blockcount;
-		return 0;
-	}
-
-	*last_block = 0;
+	if (!xfs_iext_lookup_extent_before(ip, ifp, last_block, &icur, &got))
+		*last_block = 0;
 	return 0;
 }
 
···
 	int			*is_empty)
 {
 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	struct xfs_iext_cursor	icur;
 	int			error;
-	int			nextents;
 
 	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
 		error = xfs_iread_extents(tp, ip, whichfork);
···
 			return error;
 	}
 
-	nextents = xfs_iext_count(ifp);
-	if (nextents == 0) {
+	xfs_iext_last(ifp, &icur);
+	if (!xfs_iext_get_extent(ifp, &icur, rec))
 		*is_empty = 1;
-		return 0;
-	}
-
-	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, nextents - 1), rec);
-	*is_empty = 0;
+	else
+		*is_empty = 0;
 	return 0;
 }
 
···
 	xfs_inode_t	*ip,		/* incore inode */
 	int		whichfork)	/* data or attr fork */
 {
-	xfs_bmbt_rec_host_t *ep;	/* ptr to fork's extent */
 	xfs_ifork_t	*ifp;		/* inode fork pointer */
 	int		rval;		/* return value */
 	xfs_bmbt_irec_t	s;		/* internal version of extent */
+	struct xfs_iext_cursor icur;
 
 #ifndef DEBUG
 	if (whichfork == XFS_DATA_FORK)
···
 		return 0;
 	ifp = XFS_IFORK_PTR(ip, whichfork);
 	ASSERT(ifp->if_flags & XFS_IFEXTENTS);
-	ep = xfs_iext_get_ext(ifp, 0);
-	xfs_bmbt_get_all(ep, &s);
+	xfs_iext_first(ifp, &icur);
+	xfs_iext_get_extent(ifp, &icur, &s);
 	rval = s.br_startoff == 0 && s.br_blockcount == 1;
 	if (rval && whichfork == XFS_DATA_FORK)
 		ASSERT(XFS_ISIZE(ip) == ip->i_mount->m_sb.sb_blocksize);
···
 	int			whichfork)
 {
 	struct xfs_bmbt_irec	*new = &bma->got;
-	int			diff;	/* temp value */
-	xfs_bmbt_rec_host_t	*ep;	/* extent entry for idx */
 	int			error;	/* error return value */
 	int			i;	/* temp state */
 	xfs_ifork_t		*ifp;	/* inode fork pointer */
···
 	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
 					/* left is 0, right is 1, prev is 2 */
 	int			rval=0;	/* return value (logging flags) */
-	int			state = 0;/* state bits, accessed thru macros */
+	int			state = xfs_bmap_fork_to_state(whichfork);
 	xfs_filblks_t		da_new; /* new count del alloc blocks used */
 	xfs_filblks_t		da_old; /* old count del alloc blocks used */
 	xfs_filblks_t		temp=0;	/* value for da_new calculations */
-	xfs_filblks_t		temp2=0;/* value for da_new calculations */
 	int			tmp_rval;	/* partial logging flags */
 	struct xfs_mount	*mp;
 	xfs_extnum_t		*nextents;
+	struct xfs_bmbt_irec	old;
 
 	mp = bma->ip->i_mount;
 	ifp = XFS_IFORK_PTR(bma->ip, whichfork);
···
 	nextents = (whichfork == XFS_COW_FORK ? &bma->ip->i_cnextents :
 						&bma->ip->i_d.di_nextents);
 
-	ASSERT(bma->idx >= 0);
-	ASSERT(bma->idx <= xfs_iext_count(ifp));
 	ASSERT(!isnullstartblock(new->br_startblock));
 	ASSERT(!bma->cur ||
 	       (bma->cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL));
···
 #define	RIGHT		r[1]
 #define	PREV		r[2]
 
-	if (whichfork == XFS_COW_FORK)
-		state |= BMAP_COWFORK;
-
 	/*
 	 * Set up a bunch of variables to make the tests simpler.
 	 */
-	ep = xfs_iext_get_ext(ifp, bma->idx);
-	xfs_bmbt_get_all(ep, &PREV);
+	xfs_iext_get_extent(ifp, &bma->icur, &PREV);
 	new_endoff = new->br_startoff + new->br_blockcount;
+	ASSERT(isnullstartblock(PREV.br_startblock));
 	ASSERT(PREV.br_startoff <= new->br_startoff);
 	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
 
···
 	 * Check and set flags if this segment has a left neighbor.
 	 * Don't set contiguous if the combined extent would be too large.
 	 */
-	if (bma->idx > 0) {
+	if (xfs_iext_peek_prev_extent(ifp, &bma->icur, &LEFT)) {
 		state |= BMAP_LEFT_VALID;
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx - 1), &LEFT);
-
 		if (isnullstartblock(LEFT.br_startblock))
 			state |= BMAP_LEFT_DELAY;
 	}
···
 	 * Don't set contiguous if the combined extent would be too large.
 	 * Also check for all-three-contiguous being too large.
 	 */
-	if (bma->idx < xfs_iext_count(ifp) - 1) {
+	if (xfs_iext_peek_next_extent(ifp, &bma->icur, &RIGHT)) {
 		state |= BMAP_RIGHT_VALID;
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx + 1), &RIGHT);
-
 		if (isnullstartblock(RIGHT.br_startblock))
 			state |= BMAP_RIGHT_DELAY;
 	}
···
 		 * Filling in all of a previously delayed allocation extent.
 		 * The left and right neighbors are both contiguous with new.
 		 */
-		bma->idx--;
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, bma->idx),
-			LEFT.br_blockcount + PREV.br_blockcount +
-			RIGHT.br_blockcount);
-		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+		LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
 
-		xfs_iext_remove(bma->ip, bma->idx + 1, 2, state);
+		xfs_iext_remove(bma->ip, &bma->icur, state);
+		xfs_iext_remove(bma->ip, &bma->icur, state);
+		xfs_iext_prev(ifp, &bma->icur);
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
 		(*nextents)--;
+
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			error = xfs_bmbt_lookup_eq(bma->cur, RIGHT.br_startoff,
-					RIGHT.br_startblock,
-					RIGHT.br_blockcount, &i);
+			error = xfs_bmbt_lookup_eq(bma->cur, &RIGHT, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
···
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			error = xfs_bmbt_update(bma->cur, LEFT.br_startoff,
-					LEFT.br_startblock,
-					LEFT.br_blockcount +
-					PREV.br_blockcount +
-					RIGHT.br_blockcount, LEFT.br_state);
+			error = xfs_bmbt_update(bma->cur, &LEFT);
 			if (error)
 				goto done;
 		}
···
 		 * Filling in all of a previously delayed allocation extent.
 		 * The left neighbor is contiguous, the right is not.
 		 */
-		bma->idx--;
+		old = LEFT;
+		LEFT.br_blockcount += PREV.br_blockcount;
 
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, bma->idx),
-			LEFT.br_blockcount + PREV.br_blockcount);
-		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+		xfs_iext_remove(bma->ip, &bma->icur, state);
+		xfs_iext_prev(ifp, &bma->icur);
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
 
-		xfs_iext_remove(bma->ip, bma->idx + 1, 1, state);
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_DEXT;
 		else {
 			rval = 0;
-			error = xfs_bmbt_lookup_eq(bma->cur, LEFT.br_startoff,
-					LEFT.br_startblock, LEFT.br_blockcount,
-					&i);
+			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			error = xfs_bmbt_update(bma->cur, LEFT.br_startoff,
-					LEFT.br_startblock,
-					LEFT.br_blockcount +
-					PREV.br_blockcount, LEFT.br_state);
+			error = xfs_bmbt_update(bma->cur, &LEFT);
 			if (error)
 				goto done;
 		}
···
 		 * Filling in all of a previously delayed allocation extent.
 		 * The right neighbor is contiguous, the left is not.
 		 */
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
-		xfs_bmbt_set_startblock(ep, new->br_startblock);
-		xfs_bmbt_set_blockcount(ep,
-			PREV.br_blockcount + RIGHT.br_blockcount);
-		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+		PREV.br_startblock = new->br_startblock;
+		PREV.br_blockcount += RIGHT.br_blockcount;
 
-		xfs_iext_remove(bma->ip, bma->idx + 1, 1, state);
+		xfs_iext_next(ifp, &bma->icur);
+		xfs_iext_remove(bma->ip, &bma->icur, state);
+		xfs_iext_prev(ifp, &bma->icur);
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
+
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_DEXT;
 		else {
 			rval = 0;
-			error = xfs_bmbt_lookup_eq(bma->cur, RIGHT.br_startoff,
-					RIGHT.br_startblock,
-					RIGHT.br_blockcount, &i);
+			error = xfs_bmbt_lookup_eq(bma->cur, &RIGHT, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			error = xfs_bmbt_update(bma->cur, PREV.br_startoff,
-					new->br_startblock,
-					PREV.br_blockcount +
-					RIGHT.br_blockcount, PREV.br_state);
+			error = xfs_bmbt_update(bma->cur, &PREV);
 			if (error)
 				goto done;
 		}
···
 		 * Neither the left nor right neighbors are contiguous with
 		 * the new one.
 		 */
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
-		xfs_bmbt_set_startblock(ep, new->br_startblock);
-		xfs_bmbt_set_state(ep, new->br_state);
-		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
+		PREV.br_startblock = new->br_startblock;
+		PREV.br_state = new->br_state;
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
 
 		(*nextents)++;
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			error = xfs_bmbt_lookup_eq(bma->cur, new->br_startoff,
-					new->br_startblock, new->br_blockcount,
-					&i);
+			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
-			bma->cur->bc_rec.b.br_state = XFS_EXT_NORM;
 			error = xfs_btree_insert(bma->cur, &i);
 			if (error)
 				goto done;
···
 		 * Filling in the first part of a previous delayed allocation.
 		 * The left neighbor is contiguous.
 		 */
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx - 1, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, bma->idx - 1),
-			LEFT.br_blockcount + new->br_blockcount);
-		xfs_bmbt_set_startoff(ep,
-			PREV.br_startoff + new->br_blockcount);
-		trace_xfs_bmap_post_update(bma->ip, bma->idx - 1, state, _THIS_IP_);
-
+		old = LEFT;
 		temp = PREV.br_blockcount - new->br_blockcount;
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep, temp);
+		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
+				startblockval(PREV.br_startblock));
+
+		LEFT.br_blockcount += new->br_blockcount;
+
+		PREV.br_blockcount = temp;
+		PREV.br_startoff += new->br_blockcount;
+		PREV.br_startblock = nullstartblock(da_new);
+
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
+		xfs_iext_prev(ifp, &bma->icur);
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &LEFT);
+
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_DEXT;
 		else {
 			rval = 0;
-			error = xfs_bmbt_lookup_eq(bma->cur, LEFT.br_startoff,
-					LEFT.br_startblock, LEFT.br_blockcount,
-					&i);
+			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			error = xfs_bmbt_update(bma->cur, LEFT.br_startoff,
-					LEFT.br_startblock,
-					LEFT.br_blockcount +
-					new->br_blockcount,
-					LEFT.br_state);
+			error = xfs_bmbt_update(bma->cur, &LEFT);
 			if (error)
 				goto done;
 		}
-		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
-			startblockval(PREV.br_startblock));
-		xfs_bmbt_set_startblock(ep, nullstartblock(da_new));
-		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
-
-		bma->idx--;
 		break;
 
 	case BMAP_LEFT_FILLING:
···
 		 * Filling in the first part of a previous delayed allocation.
 		 * The left neighbor is not contiguous.
 		 */
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
-		xfs_bmbt_set_startoff(ep, new_endoff);
-		temp = PREV.br_blockcount - new->br_blockcount;
-		xfs_bmbt_set_blockcount(ep, temp);
-		xfs_iext_insert(bma->ip, bma->idx, 1, new, state);
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
 		(*nextents)++;
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			error = xfs_bmbt_lookup_eq(bma->cur, new->br_startoff,
-					new->br_startblock, new->br_blockcount,
-					&i);
+			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
-			bma->cur->bc_rec.b.br_state = XFS_EXT_NORM;
 			error = xfs_btree_insert(bma->cur, &i);
 			if (error)
 				goto done;
···
 			if (error)
 				goto done;
 		}
+
+		temp = PREV.br_blockcount - new->br_blockcount;
 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
 			startblockval(PREV.br_startblock) -
 			(bma->cur ? bma->cur->bc_private.b.allocated : 0));
-		ep = xfs_iext_get_ext(ifp, bma->idx + 1);
-		xfs_bmbt_set_startblock(ep, nullstartblock(da_new));
-		trace_xfs_bmap_post_update(bma->ip, bma->idx + 1, state, _THIS_IP_);
+
+		PREV.br_startoff = new_endoff;
+		PREV.br_blockcount = temp;
+		PREV.br_startblock = nullstartblock(da_new);
+		xfs_iext_next(ifp, &bma->icur);
+		xfs_iext_insert(bma->ip, &bma->icur, &PREV, state);
+		xfs_iext_prev(ifp, &bma->icur);
 		break;
 
 	case BMAP_RIGHT_FILLING | BMAP_RIGHT_CONTIG:
···
 		 * Filling in the last part of a previous delayed allocation.
 		 * The right neighbor is contiguous with the new allocation.
 		 */
-		temp = PREV.br_blockcount - new->br_blockcount;
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx + 1, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep, temp);
-		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, bma->idx + 1),
-			new->br_startoff, new->br_startblock,
-			new->br_blockcount + RIGHT.br_blockcount,
-			RIGHT.br_state);
-		trace_xfs_bmap_post_update(bma->ip, bma->idx + 1, state, _THIS_IP_);
+		old = RIGHT;
+		RIGHT.br_startoff = new->br_startoff;
+		RIGHT.br_startblock = new->br_startblock;
+		RIGHT.br_blockcount += new->br_blockcount;
+
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_DEXT;
 		else {
 			rval = 0;
-			error = xfs_bmbt_lookup_eq(bma->cur, RIGHT.br_startoff,
-					RIGHT.br_startblock,
-					RIGHT.br_blockcount, &i);
+			error = xfs_bmbt_lookup_eq(bma->cur, &old, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			error = xfs_bmbt_update(bma->cur, new->br_startoff,
-					new->br_startblock,
-					new->br_blockcount +
-					RIGHT.br_blockcount,
-					RIGHT.br_state);
+			error = xfs_bmbt_update(bma->cur, &RIGHT);
 			if (error)
 				goto done;
 		}
 
+		temp = PREV.br_blockcount - new->br_blockcount;
 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
 			startblockval(PREV.br_startblock));
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
-		xfs_bmbt_set_startblock(ep, nullstartblock(da_new));
-		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
 
-		bma->idx++;
+		PREV.br_blockcount = temp;
+		PREV.br_startblock = nullstartblock(da_new);
+
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
+		xfs_iext_next(ifp, &bma->icur);
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &RIGHT);
 		break;
 
 	case BMAP_RIGHT_FILLING:
···
 		 * Filling in the last part of a previous delayed allocation.
 		 * The right neighbor is not contiguous.
 		 */
-		temp = PREV.br_blockcount - new->br_blockcount;
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep, temp);
-		xfs_iext_insert(bma->ip, bma->idx + 1, 1, new, state);
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, new);
 		(*nextents)++;
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			error = xfs_bmbt_lookup_eq(bma->cur, new->br_startoff,
-					new->br_startblock, new->br_blockcount,
-					&i);
+			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
-			bma->cur->bc_rec.b.br_state = XFS_EXT_NORM;
 			error = xfs_btree_insert(bma->cur, &i);
 			if (error)
 				goto done;
···
 			if (error)
 				goto done;
 		}
+
+		temp = PREV.br_blockcount - new->br_blockcount;
 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(bma->ip, temp),
 			startblockval(PREV.br_startblock) -
 			(bma->cur ? bma->cur->bc_private.b.allocated : 0));
-		ep = xfs_iext_get_ext(ifp, bma->idx);
-		xfs_bmbt_set_startblock(ep, nullstartblock(da_new));
-		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
 
-		bma->idx++;
+		PREV.br_startblock = nullstartblock(da_new);
+		PREV.br_blockcount = temp;
+		xfs_iext_insert(bma->ip, &bma->icur, &PREV, state);
+		xfs_iext_next(ifp, &bma->icur);
 		break;
 
 	case 0:
···
 		 *  PREV @ idx          LEFT              RIGHT
 		 *                      inserted at idx + 1
 		 */
-		temp = new->br_startoff - PREV.br_startoff;
-		temp2 = PREV.br_startoff + PREV.br_blockcount - new_endoff;
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx, 0, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep, temp);	/* truncate PREV */
+		old = PREV;
+
+		/* LEFT is the new middle */
 		LEFT = *new;
+
+		/* RIGHT is the new right */
 		RIGHT.br_state = PREV.br_state;
-		RIGHT.br_startblock = nullstartblock(
-				(int)xfs_bmap_worst_indlen(bma->ip, temp2));
 		RIGHT.br_startoff = new_endoff;
-		RIGHT.br_blockcount = temp2;
-		/* insert LEFT (r[0]) and RIGHT (r[1]) at the same time */
-		xfs_iext_insert(bma->ip, bma->idx + 1, 2, &LEFT, state);
+		RIGHT.br_blockcount =
+			PREV.br_startoff + PREV.br_blockcount - new_endoff;
+		RIGHT.br_startblock =
+			nullstartblock(xfs_bmap_worst_indlen(bma->ip,
+					RIGHT.br_blockcount));
+
+		/* truncate PREV */
+		PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
+		PREV.br_startblock =
+			nullstartblock(xfs_bmap_worst_indlen(bma->ip,
+					PREV.br_blockcount));
+		xfs_iext_update_extent(bma->ip, state, &bma->icur, &PREV);
+
+		xfs_iext_next(ifp, &bma->icur);
+		xfs_iext_insert(bma->ip, &bma->icur, &RIGHT, state);
+		xfs_iext_insert(bma->ip, &bma->icur, &LEFT, state);
 		(*nextents)++;
+
 		if (bma->cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			error = xfs_bmbt_lookup_eq(bma->cur, new->br_startoff,
-					new->br_startblock, new->br_blockcount,
-					&i);
+			error = xfs_bmbt_lookup_eq(bma->cur, new, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
-			bma->cur->bc_rec.b.br_state = XFS_EXT_NORM;
 			error = xfs_btree_insert(bma->cur, &i);
 			if (error)
 				goto done;
···
 			if (error)
 				goto done;
 		}
-		temp = xfs_bmap_worst_indlen(bma->ip, temp);
-		temp2 = xfs_bmap_worst_indlen(bma->ip, temp2);
-		diff = (int)(temp + temp2 -
-			     (startblockval(PREV.br_startblock) -
-			      (bma->cur ?
-			       bma->cur->bc_private.b.allocated : 0)));
-		if (diff > 0) {
-			error = xfs_mod_fdblocks(bma->ip->i_mount,
-						 -((int64_t)diff), false);
-			ASSERT(!error);
-			if (error)
-				goto done;
-		}
 
-		ep = xfs_iext_get_ext(ifp, bma->idx);
-		xfs_bmbt_set_startblock(ep, nullstartblock((int)temp));
-		trace_xfs_bmap_post_update(bma->ip, bma->idx, state, _THIS_IP_);
-		trace_xfs_bmap_pre_update(bma->ip, bma->idx + 2, state, _THIS_IP_);
-		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, bma->idx + 2),
-			nullstartblock((int)temp2));
-		trace_xfs_bmap_post_update(bma->ip, bma->idx + 2, state, _THIS_IP_);
-
-		bma->idx++;
-		da_new = temp + temp2;
+		da_new = startblockval(PREV.br_startblock) +
+			 startblockval(RIGHT.br_startblock);
 		break;
 
 	case BMAP_LEFT_FILLING | BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
···
 			goto done;
 	}
 
-	/* adjust for changes in reserved delayed indirect blocks */
-	if (da_old || da_new) {
-		temp = da_new;
-		if (bma->cur)
-			temp += bma->cur->bc_private.b.allocated;
-		if (temp < da_old)
-			xfs_mod_fdblocks(bma->ip->i_mount,
-					(int64_t)(da_old - temp), false);
+	if (bma->cur) {
+		da_new += bma->cur->bc_private.b.allocated;
+		bma->cur->bc_private.b.allocated = 0;
 	}
 
-	/* clear out the allocated field, done with it now in any case. */
-	if (bma->cur)
-		bma->cur->bc_private.b.allocated = 0;
+	/* adjust for changes in reserved delayed indirect blocks */
+	if (da_new != da_old) {
+		ASSERT(state == 0 || da_new < da_old);
+		error = xfs_mod_fdblocks(mp, (int64_t)(da_old - da_new),
+				false);
+	}
 
 	xfs_bmap_check_leaf_extents(bma->cur, bma->ip, whichfork);
 done:
···
 	struct xfs_trans	*tp,
 	xfs_inode_t		*ip,	/* incore inode pointer */
 	int			whichfork,
-	xfs_extnum_t		*idx,	/* extent number to update/insert */
+	struct xfs_iext_cursor	*icur,
 	xfs_btree_cur_t		**curp,	/* if *curp is null, not a btree */
 	xfs_bmbt_irec_t		*new,	/* new data to add to file extents */
 	xfs_fsblock_t		*first,	/* pointer to firstblock variable */
···
 	int			*logflagsp) /* inode logging flags */
 {
 	xfs_btree_cur_t		*cur;	/* btree cursor */
-	xfs_bmbt_rec_host_t	*ep;	/* extent entry for idx */
 	int			error;	/* error return value */
 	int			i;	/* temp state */
 	xfs_ifork_t		*ifp;	/* inode fork pointer */
 	xfs_fileoff_t		new_endoff;	/* end offset of new entry */
-	xfs_exntst_t		newext;	/* new extent state */
-	xfs_exntst_t		oldext;	/* old extent state */
 	xfs_bmbt_irec_t		r[3];	/* neighbor extent entries */
 					/* left is 0, right is 1, prev is 2 */
 	int			rval=0;	/* return value (logging flags) */
-	int			state = 0;/* state bits, accessed thru macros */
+	int			state = xfs_bmap_fork_to_state(whichfork);
 	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_bmbt_irec	old;
 
 	*logflagsp = 0;
 
 	cur = *curp;
 	ifp = XFS_IFORK_PTR(ip, whichfork);
-	if (whichfork == XFS_COW_FORK)
-		state |= BMAP_COWFORK;
 
-	ASSERT(*idx >= 0);
-	ASSERT(*idx <= xfs_iext_count(ifp));
 	ASSERT(!isnullstartblock(new->br_startblock));
 
 	XFS_STATS_INC(mp, xs_add_exlist);
···
 	 * Set up a bunch of variables to make the tests simpler.
 	 */
 	error = 0;
-	ep = xfs_iext_get_ext(ifp, *idx);
-	xfs_bmbt_get_all(ep, &PREV);
-	newext = new->br_state;
-	oldext = (newext == XFS_EXT_UNWRITTEN) ?
-		XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
-	ASSERT(PREV.br_state == oldext);
+	xfs_iext_get_extent(ifp, icur, &PREV);
+	ASSERT(new->br_state != PREV.br_state);
 	new_endoff = new->br_startoff + new->br_blockcount;
 	ASSERT(PREV.br_startoff <= new->br_startoff);
 	ASSERT(PREV.br_startoff + PREV.br_blockcount >= new_endoff);
···
 	 * Check and set flags if this segment has a left neighbor.
 	 * Don't set contiguous if the combined extent would be too large.
 	 */
-	if (*idx > 0) {
+	if (xfs_iext_peek_prev_extent(ifp, icur, &LEFT)) {
 		state |= BMAP_LEFT_VALID;
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx - 1), &LEFT);
-
 		if (isnullstartblock(LEFT.br_startblock))
 			state |= BMAP_LEFT_DELAY;
 	}
···
 	if ((state & BMAP_LEFT_VALID) && !(state & BMAP_LEFT_DELAY) &&
 	    LEFT.br_startoff + LEFT.br_blockcount == new->br_startoff &&
 	    LEFT.br_startblock + LEFT.br_blockcount == new->br_startblock &&
-	    LEFT.br_state == newext &&
+	    LEFT.br_state == new->br_state &&
 	    LEFT.br_blockcount + new->br_blockcount <= MAXEXTLEN)
 		state |= BMAP_LEFT_CONTIG;
 
···
 	 * Don't set contiguous if the combined extent would be too large.
 	 * Also check for all-three-contiguous being too large.
 	 */
-	if (*idx < xfs_iext_count(ifp) - 1) {
+	if (xfs_iext_peek_next_extent(ifp, icur, &RIGHT)) {
 		state |= BMAP_RIGHT_VALID;
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx + 1), &RIGHT);
 		if (isnullstartblock(RIGHT.br_startblock))
 			state |= BMAP_RIGHT_DELAY;
 	}
···
 	if ((state & BMAP_RIGHT_VALID) && !(state & BMAP_RIGHT_DELAY) &&
 	    new_endoff == RIGHT.br_startoff &&
 	    new->br_startblock + new->br_blockcount == RIGHT.br_startblock &&
-	    newext == RIGHT.br_state &&
+	    new->br_state == RIGHT.br_state &&
 	    new->br_blockcount + RIGHT.br_blockcount <= MAXEXTLEN &&
 	    ((state & (BMAP_LEFT_CONTIG | BMAP_LEFT_FILLING |
 		       BMAP_RIGHT_FILLING)) !=
···
 		 * Setting all of a previous oldext extent to newext.
 		 * The left and right neighbors are both contiguous with new.
 		 */
-		--*idx;
+		LEFT.br_blockcount += PREV.br_blockcount + RIGHT.br_blockcount;
 
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx),
-			LEFT.br_blockcount + PREV.br_blockcount +
-			RIGHT.br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
-
-		xfs_iext_remove(ip, *idx + 1, 2, state);
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_prev(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &LEFT);
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 				XFS_IFORK_NEXTENTS(ip, whichfork) - 2);
 		if (cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			if ((error = xfs_bmbt_lookup_eq(cur, RIGHT.br_startoff,
-					RIGHT.br_startblock,
-					RIGHT.br_blockcount, &i)))
+			error = xfs_bmbt_lookup_eq(cur, &RIGHT, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
 			if ((error = xfs_btree_delete(cur, &i)))
···
 			if ((error = xfs_btree_decrement(cur, 0, &i)))
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
-				LEFT.br_startblock,
-				LEFT.br_blockcount + PREV.br_blockcount +
-				RIGHT.br_blockcount, LEFT.br_state)))
+			error = xfs_bmbt_update(cur, &LEFT);
+			if (error)
 				goto done;
 		}
 		break;
···
 		 * Setting all of a previous oldext extent to newext.
 		 * The left neighbor is contiguous, the right is not.
 		 */
-		--*idx;
+		LEFT.br_blockcount += PREV.br_blockcount;
 
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx),
-			LEFT.br_blockcount + PREV.br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
-
-		xfs_iext_remove(ip, *idx + 1, 1, state);
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_prev(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &LEFT);
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 				XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
 		if (cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
-					PREV.br_startblock, PREV.br_blockcount,
-					&i)))
+			error = xfs_bmbt_lookup_eq(cur, &PREV, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
 			if ((error = xfs_btree_delete(cur, &i)))
···
 			if ((error = xfs_btree_decrement(cur, 0, &i)))
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			if ((error = xfs_bmbt_update(cur, LEFT.br_startoff,
-				LEFT.br_startblock,
-				LEFT.br_blockcount + PREV.br_blockcount,
-				LEFT.br_state)))
+			error = xfs_bmbt_update(cur, &LEFT);
+			if (error)
 				goto done;
 		}
 		break;
···
 		 * Setting all of a previous oldext extent to newext.
 		 * The right neighbor is contiguous, the left is not.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep,
-			PREV.br_blockcount + RIGHT.br_blockcount);
-		xfs_bmbt_set_state(ep, newext);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
-		xfs_iext_remove(ip, *idx + 1, 1, state);
+		PREV.br_blockcount += RIGHT.br_blockcount;
+		PREV.br_state = new->br_state;
+
+		xfs_iext_next(ifp, icur);
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_prev(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &PREV);
+
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 				XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
 		if (cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			if ((error = xfs_bmbt_lookup_eq(cur, RIGHT.br_startoff,
-					RIGHT.br_startblock,
-					RIGHT.br_blockcount, &i)))
+			error = xfs_bmbt_lookup_eq(cur, &RIGHT, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
 			if ((error = xfs_btree_delete(cur, &i)))
···
 			if ((error = xfs_btree_decrement(cur, 0, &i)))
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			if ((error = xfs_bmbt_update(cur, new->br_startoff,
-				new->br_startblock,
-				new->br_blockcount + RIGHT.br_blockcount,
-				newext)))
+			error = xfs_bmbt_update(cur, &PREV);
+			if (error)
 				goto done;
 		}
 		break;
···
 		 * Neither the left nor right neighbors are contiguous with
 		 * the new one.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_state(ep, newext);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		PREV.br_state = new->br_state;
+		xfs_iext_update_extent(ip, state, icur, &PREV);
 
 		if (cur == NULL)
 			rval = XFS_ILOG_DEXT;
 		else {
 			rval = 0;
-			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
-					new->br_startblock, new->br_blockcount,
-					&i)))
+			error = xfs_bmbt_lookup_eq(cur, new, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			if ((error = xfs_bmbt_update(cur, new->br_startoff,
-				new->br_startblock, new->br_blockcount,
-				newext)))
+			error = xfs_bmbt_update(cur, &PREV);
+			if (error)
 				goto done;
 		}
 		break;
···
 		 * Setting the first part of a previous oldext extent to newext.
 		 * The left neighbor is contiguous.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx - 1, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx - 1),
-			LEFT.br_blockcount + new->br_blockcount);
-		xfs_bmbt_set_startoff(ep,
-			PREV.br_startoff + new->br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx - 1, state, _THIS_IP_);
+		LEFT.br_blockcount += new->br_blockcount;
 
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_startblock(ep,
-			new->br_startblock + new->br_blockcount);
-		xfs_bmbt_set_blockcount(ep,
-			PREV.br_blockcount - new->br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		old = PREV;
+		PREV.br_startoff += new->br_blockcount;
+		PREV.br_startblock += new->br_blockcount;
+		PREV.br_blockcount -= new->br_blockcount;
 
-		--*idx;
+		xfs_iext_update_extent(ip, state, icur, &PREV);
+		xfs_iext_prev(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &LEFT);
 
 		if (cur == NULL)
 			rval = XFS_ILOG_DEXT;
 		else {
 			rval = 0;
-			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
-					PREV.br_startblock, PREV.br_blockcount,
-					&i)))
+			error = xfs_bmbt_lookup_eq(cur, &old, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			if ((error = xfs_bmbt_update(cur,
-				PREV.br_startoff + new->br_blockcount,
-				PREV.br_startblock + new->br_blockcount,
-				PREV.br_blockcount - new->br_blockcount,
-				oldext)))
+			error = xfs_bmbt_update(cur, &PREV);
+			if (error)
 				goto done;
-			if ((error = xfs_btree_decrement(cur, 0, &i)))
+			error = xfs_btree_decrement(cur, 0, &i);
+			if (error)
 				goto done;
-			error = xfs_bmbt_update(cur, LEFT.br_startoff,
-				LEFT.br_startblock,
-				LEFT.br_blockcount + new->br_blockcount,
-				LEFT.br_state);
+			error = xfs_bmbt_update(cur, &LEFT);
 			if (error)
 				goto done;
 		}
···
 		 * Setting the first part of a previous oldext extent to newext.
 		 * The left neighbor is not contiguous.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		ASSERT(ep && xfs_bmbt_get_state(ep) == oldext);
-		xfs_bmbt_set_startoff(ep, new_endoff);
-		xfs_bmbt_set_blockcount(ep,
-			PREV.br_blockcount - new->br_blockcount);
-		xfs_bmbt_set_startblock(ep,
-			new->br_startblock + new->br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		old = PREV;
+		PREV.br_startoff += new->br_blockcount;
+		PREV.br_startblock += new->br_blockcount;
+		PREV.br_blockcount -= new->br_blockcount;
 
-		xfs_iext_insert(ip, *idx, 1, new, state);
+		xfs_iext_update_extent(ip, state, icur, &PREV);
+		xfs_iext_insert(ip, icur, new, state);
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 				XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
 		if (cur == NULL)
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
-					PREV.br_startblock, PREV.br_blockcount,
-					&i)))
+			error = xfs_bmbt_lookup_eq(cur, &old, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			if ((error = xfs_bmbt_update(cur,
-				PREV.br_startoff + new->br_blockcount,
-				PREV.br_startblock + new->br_blockcount,
-				PREV.br_blockcount - new->br_blockcount,
-				oldext)))
+			error = xfs_bmbt_update(cur, &PREV);
+			if (error)
 				goto done;
 			cur->bc_rec.b = *new;
 			if ((error = xfs_btree_insert(cur, &i)))
···
 		 * Setting the last part of a previous oldext extent to newext.
 		 * The right neighbor is contiguous with the new allocation.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep,
-			PREV.br_blockcount - new->br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		old = PREV;
+		PREV.br_blockcount -= new->br_blockcount;
 
-		++*idx;
+		RIGHT.br_startoff = new->br_startoff;
+		RIGHT.br_startblock = new->br_startblock;
+		RIGHT.br_blockcount += new->br_blockcount;
 
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, *idx),
-			new->br_startoff, new->br_startblock,
-			new->br_blockcount + RIGHT.br_blockcount, newext);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		xfs_iext_update_extent(ip, state, icur, &PREV);
+		xfs_iext_next(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &RIGHT);
 
 		if (cur == NULL)
 			rval = XFS_ILOG_DEXT;
 		else {
 			rval = 0;
-			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
-					PREV.br_startblock,
-					PREV.br_blockcount, &i)))
+			error = xfs_bmbt_lookup_eq(cur, &old, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
-				PREV.br_startblock,
-				PREV.br_blockcount - new->br_blockcount,
-				oldext)))
+			error = xfs_bmbt_update(cur, &PREV);
+			if (error)
 				goto done;
-			if ((error = xfs_btree_increment(cur, 0, &i)))
+			error = xfs_btree_increment(cur, 0, &i);
+			if (error)
 				goto done;
-			if ((error = xfs_bmbt_update(cur, new->br_startoff,
-				new->br_startblock,
-				new->br_blockcount + RIGHT.br_blockcount,
-				newext)))
+			error = xfs_bmbt_update(cur, &RIGHT);
+			if (error)
 				goto done;
 		}
 		break;
···
 		 * Setting the last part of a previous oldext extent to newext.
 		 * The right neighbor is not contiguous.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep,
-			PREV.br_blockcount - new->br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		old = PREV;
+		PREV.br_blockcount -= new->br_blockcount;
 
-		++*idx;
-		xfs_iext_insert(ip, *idx, 1, new, state);
+		xfs_iext_update_extent(ip, state, icur, &PREV);
+		xfs_iext_next(ifp, icur);
+		xfs_iext_insert(ip, icur, new, state);
 
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 				XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
···
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
-					PREV.br_startblock, PREV.br_blockcount,
-					&i)))
+			error = xfs_bmbt_lookup_eq(cur, &old, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			if ((error = xfs_bmbt_update(cur, PREV.br_startoff,
-				PREV.br_startblock,
-				PREV.br_blockcount - new->br_blockcount,
-				oldext)))
+			error = xfs_bmbt_update(cur, &PREV);
+			if (error)
 				goto done;
-			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
-					new->br_startblock, new->br_blockcount,
-					&i)))
+			error = xfs_bmbt_lookup_eq(cur, new, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
-			cur->bc_rec.b.br_state = XFS_EXT_NORM;
 			if ((error = xfs_btree_insert(cur, &i)))
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
···
 		 * newext.  Contiguity is impossible here.
 		 * One extent becomes three extents.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep,
-			new->br_startoff - PREV.br_startoff);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		old = PREV;
+		PREV.br_blockcount = new->br_startoff - PREV.br_startoff;
 
 		r[0] = *new;
 		r[1].br_startoff = new_endoff;
 		r[1].br_blockcount =
-			PREV.br_startoff + PREV.br_blockcount - new_endoff;
+			old.br_startoff + old.br_blockcount - new_endoff;
 		r[1].br_startblock = new->br_startblock + new->br_blockcount;
-		r[1].br_state = oldext;
+		r[1].br_state = PREV.br_state;
 
-		++*idx;
-		xfs_iext_insert(ip, *idx, 2, &r[0], state);
+		xfs_iext_update_extent(ip, state, icur, &PREV);
+		xfs_iext_next(ifp, icur);
+		xfs_iext_insert(ip, icur, &r[1], state);
+		xfs_iext_insert(ip, icur, &r[0], state);
 
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 				XFS_IFORK_NEXTENTS(ip, whichfork) + 2);
···
 			rval = XFS_ILOG_CORE | XFS_ILOG_DEXT;
 		else {
 			rval = XFS_ILOG_CORE;
-			if ((error = xfs_bmbt_lookup_eq(cur, PREV.br_startoff,
-					PREV.br_startblock, PREV.br_blockcount,
-					&i)))
+			error = xfs_bmbt_lookup_eq(cur, &old, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
 			/* new right extent - oldext */
-			if ((error = xfs_bmbt_update(cur, r[1].br_startoff,
-				r[1].br_startblock, r[1].br_blockcount,
-				r[1].br_state)))
+			error = xfs_bmbt_update(cur, &r[1]);
+			if (error)
 				goto done;
 			/* new left extent - oldext */
 			cur->bc_rec.b = PREV;
-			cur->bc_rec.b.br_blockcount =
-				new->br_startoff - PREV.br_startoff;
 			if ((error = xfs_btree_insert(cur, &i)))
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
···
 			 * we are about to insert as we can't trust it after
 			 * the previous insert.
 			 */
-			if ((error = xfs_bmbt_lookup_eq(cur, new->br_startoff,
-					new->br_startblock, new->br_blockcount,
-					&i)))
+			error = xfs_bmbt_lookup_eq(cur, new, &i);
+			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
 			/* new middle extent - newext */
-			cur->bc_rec.b.br_state = new->br_state;
 			if ((error = xfs_btree_insert(cur, &i)))
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
···
 xfs_bmap_add_extent_hole_delay(
 	xfs_inode_t		*ip,	/* incore inode pointer */
 	int			whichfork,
-	xfs_extnum_t		*idx,	/* extent number to update/insert */
+	struct xfs_iext_cursor	*icur,
 	xfs_bmbt_irec_t		*new)	/* new data to add to file extents */
 {
 	xfs_ifork_t		*ifp;	/* inode fork pointer */
···
 	xfs_filblks_t		newlen=0;	/* new indirect size */
 	xfs_filblks_t		oldlen=0;	/* old indirect size */
 	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
-	int			state;  /* state bits, accessed thru macros */
-	xfs_filblks_t		temp=0;	/* temp for indirect calculations */
+	int			state = xfs_bmap_fork_to_state(whichfork);
+	xfs_filblks_t		temp;	 /* temp for indirect calculations */
 
 	ifp = XFS_IFORK_PTR(ip, whichfork);
-	state = 0;
-	if (whichfork == XFS_COW_FORK)
-		state |= BMAP_COWFORK;
 	ASSERT(isnullstartblock(new->br_startblock));
 
 	/*
 	 * Check and set flags if this segment has a left neighbor
 	 */
-	if (*idx > 0) {
+	if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
 		state |= BMAP_LEFT_VALID;
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx - 1), &left);
-
 		if (isnullstartblock(left.br_startblock))
 			state |= BMAP_LEFT_DELAY;
 	}
···
 	 * Check and set flags if the current (right) segment exists.
 	 * If it doesn't exist, we're converting the hole at end-of-file.
 	 */
-	if (*idx < xfs_iext_count(ifp)) {
+	if (xfs_iext_get_extent(ifp, icur, &right)) {
 		state |= BMAP_RIGHT_VALID;
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx), &right);
-
 		if (isnullstartblock(right.br_startblock))
 			state |= BMAP_RIGHT_DELAY;
 	}
···
 		 * on the left and on the right.
 		 * Merge all three into a single extent record.
 		 */
-		--*idx;
 		temp = left.br_blockcount + new->br_blockcount +
 			right.br_blockcount;
 
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx), temp);
 		oldlen = startblockval(left.br_startblock) +
 			startblockval(new->br_startblock) +
 			startblockval(right.br_startblock);
 		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
 					 oldlen);
-		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, *idx),
-			nullstartblock((int)newlen));
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		left.br_startblock = nullstartblock(newlen);
+		left.br_blockcount = temp;
 
-		xfs_iext_remove(ip, *idx + 1, 1, state);
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_prev(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &left);
 		break;
 
 	case BMAP_LEFT_CONTIG:
···
 		 * on the left.
 		 * Merge the new allocation with the left neighbor.
 		 */
-		--*idx;
 		temp = left.br_blockcount + new->br_blockcount;
 
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx), temp);
 		oldlen = startblockval(left.br_startblock) +
 			startblockval(new->br_startblock);
 		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
 					 oldlen);
-		xfs_bmbt_set_startblock(xfs_iext_get_ext(ifp, *idx),
-			nullstartblock((int)newlen));
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		left.br_blockcount = temp;
+		left.br_startblock = nullstartblock(newlen);
+
+		xfs_iext_prev(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &left);
 		break;
 
 	case BMAP_RIGHT_CONTIG:
···
 		 * on the right.
 		 * Merge the new allocation with the right neighbor.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
 		temp = new->br_blockcount + right.br_blockcount;
 		oldlen = startblockval(new->br_startblock) +
 			startblockval(right.br_startblock);
 		newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
 					 oldlen);
-		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, *idx),
-			new->br_startoff,
-			nullstartblock((int)newlen), temp, right.br_state);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		right.br_startoff = new->br_startoff;
+		right.br_startblock = nullstartblock(newlen);
+		right.br_blockcount = temp;
+		xfs_iext_update_extent(ip, state, icur, &right);
 		break;
 
 	case 0:
···
 		 * Insert a new entry.
 		 */
 		oldlen = newlen = 0;
-		xfs_iext_insert(ip, *idx, 1, new, state);
+		xfs_iext_insert(ip, icur, new, state);
 		break;
 	}
 	if (oldlen != newlen) {
···
 	struct xfs_trans	*tp,
 	struct xfs_inode	*ip,
 	int			whichfork,
-	xfs_extnum_t		*idx,
+	struct xfs_iext_cursor	*icur,
 	struct xfs_btree_cur	**curp,
 	struct xfs_bmbt_irec	*new,
 	xfs_fsblock_t		*first,
···
 	xfs_bmbt_irec_t		left;	/* left neighbor extent entry */
 	xfs_bmbt_irec_t		right;	/* right neighbor extent entry */
 	int			rval=0;	/* return value (logging flags) */
-	int			state;	/* state bits, accessed thru macros */
+	int			state = xfs_bmap_fork_to_state(whichfork);
+	struct xfs_bmbt_irec	old;
 
-	ASSERT(*idx >= 0);
-	ASSERT(*idx <= xfs_iext_count(ifp));
 	ASSERT(!isnullstartblock(new->br_startblock));
 	ASSERT(!cur || !(cur->bc_private.b.flags & XFS_BTCUR_BPRV_WASDEL));
 
 	XFS_STATS_INC(mp, xs_add_exlist);
 
-	state = 0;
-	if (whichfork == XFS_ATTR_FORK)
-		state |= BMAP_ATTRFORK;
-	if (whichfork == XFS_COW_FORK)
-		state |= BMAP_COWFORK;
-
 	/*
 	 * Check and set flags if this segment has a left neighbor.
 	 */
-	if (*idx > 0) {
+	if (xfs_iext_peek_prev_extent(ifp, icur, &left)) {
 		state |= BMAP_LEFT_VALID;
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx - 1), &left);
 		if (isnullstartblock(left.br_startblock))
 			state |= BMAP_LEFT_DELAY;
 	}
···
 	 * Check and set flags if this segment has a current value.
 	 * Not true if we're inserting into the "hole" at eof.
 	 */
-	if (*idx < xfs_iext_count(ifp)) {
+	if (xfs_iext_get_extent(ifp, icur, &right)) {
 		state |= BMAP_RIGHT_VALID;
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, *idx), &right);
 		if (isnullstartblock(right.br_startblock))
 			state |= BMAP_RIGHT_DELAY;
 	}
···
 		 * left and on the right.
 		 * Merge all three into a single extent record.
 		 */
-		--*idx;
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx),
-			left.br_blockcount + new->br_blockcount +
-			right.br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		left.br_blockcount += new->br_blockcount + right.br_blockcount;
 
-		xfs_iext_remove(ip, *idx + 1, 1, state);
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_prev(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &left);
 
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 			XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
···
 			rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
 		} else {
 			rval = XFS_ILOG_CORE;
-			error = xfs_bmbt_lookup_eq(cur, right.br_startoff,
-					right.br_startblock, right.br_blockcount,
-					&i);
+			error = xfs_bmbt_lookup_eq(cur, &right, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
···
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			error = xfs_bmbt_update(cur, left.br_startoff,
-					left.br_startblock,
-					left.br_blockcount +
-						new->br_blockcount +
-						right.br_blockcount,
-					left.br_state);
+			error = xfs_bmbt_update(cur, &left);
 			if (error)
 				goto done;
 		}
···
 		 * on the left.
 		 * Merge the new allocation with the left neighbor.
 		 */
-		--*idx;
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(xfs_iext_get_ext(ifp, *idx),
-			left.br_blockcount + new->br_blockcount);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		old = left;
+		left.br_blockcount += new->br_blockcount;
+
+		xfs_iext_prev(ifp, icur);
+		xfs_iext_update_extent(ip, state, icur, &left);
 
 		if (cur == NULL) {
 			rval = xfs_ilog_fext(whichfork);
 		} else {
 			rval = 0;
-			error = xfs_bmbt_lookup_eq(cur, left.br_startoff,
-					left.br_startblock, left.br_blockcount,
-					&i);
+			error = xfs_bmbt_lookup_eq(cur, &old, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			error = xfs_bmbt_update(cur, left.br_startoff,
-					left.br_startblock,
-					left.br_blockcount +
-						new->br_blockcount,
-					left.br_state);
+			error = xfs_bmbt_update(cur, &left);
 			if (error)
 				goto done;
 		}
···
 		 * on the right.
 		 * Merge the new allocation with the right neighbor.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_allf(xfs_iext_get_ext(ifp, *idx),
-			new->br_startoff, new->br_startblock,
-			new->br_blockcount + right.br_blockcount,
-			right.br_state);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		old = right;
+
+		right.br_startoff = new->br_startoff;
+		right.br_startblock = new->br_startblock;
+		right.br_blockcount += new->br_blockcount;
+		xfs_iext_update_extent(ip, state, icur, &right);
 
 		if (cur == NULL) {
 			rval = xfs_ilog_fext(whichfork);
 		} else {
 			rval = 0;
-			error = xfs_bmbt_lookup_eq(cur,
-					right.br_startoff,
-					right.br_startblock,
-					right.br_blockcount, &i);
+			error = xfs_bmbt_lookup_eq(cur, &old, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			error = xfs_bmbt_update(cur, new->br_startoff,
-					new->br_startblock,
-					new->br_blockcount +
-						right.br_blockcount,
-					right.br_state);
+			error = xfs_bmbt_update(cur, &right);
 			if (error)
 				goto done;
 		}
···
 		 * real allocation.
 		 * Insert a new entry.
 		 */
-		xfs_iext_insert(ip, *idx, 1, new, state);
+		xfs_iext_insert(ip, icur, new, state);
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 			XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
 		if (cur == NULL) {
 			rval = XFS_ILOG_CORE | xfs_ilog_fext(whichfork);
 		} else {
 			rval = XFS_ILOG_CORE;
-			error = xfs_bmbt_lookup_eq(cur,
-					new->br_startoff,
-					new->br_startblock,
-					new->br_blockcount, &i);
+			error = xfs_bmbt_lookup_eq(cur, new, &i);
 			if (error)
 				goto done;
 			XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done);
-			cur->bc_rec.b.br_state = new->br_state;
 			error = xfs_btree_insert(cur, &i);
 			if (error)
 				goto done;
···
 	struct xfs_bmbt_irec	got;
 	xfs_fileoff_t		obno;
 	xfs_fileoff_t		end;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	icur;
 	int			error;
 	bool			eof = false;
 	int			n = 0;
···
 			return error;
 	}
 
-	if (!xfs_iext_lookup_extent(ip, ifp, bno, &idx, &got))
+	if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got))
 		eof = true;
 	end = bno + len;
 	obno = bno;
···
 			break;
 
 		/* Else go on to the next record. */
-		if (!xfs_iext_get_extent(ifp, ++idx, &got))
+		if (!xfs_iext_next_extent(ifp, &icur, &got))
 			eof = true;
 	}
 	*nmap = n;
···
 	xfs_filblks_t		len,
 	xfs_filblks_t		prealloc,
 	struct xfs_bmbt_irec	*got,
-	xfs_extnum_t		*lastx,
+	struct xfs_iext_cursor	*icur,
 	int			eof)
 {
 	struct xfs_mount	*mp = ip->i_mount;
···
 	if (extsz) {
 		struct xfs_bmbt_irec	prev;
 
-		if (!xfs_iext_get_extent(ifp, *lastx - 1, &prev))
+		if (!xfs_iext_peek_prev_extent(ifp, icur, &prev))
 			prev.br_startoff = NULLFILEOFF;
 
 		error = xfs_bmap_extsize_align(mp, got, &prev, extsz, rt, eof,
···
 	got->br_blockcount = alen;
 	got->br_state = XFS_EXT_NORM;
 
-	xfs_bmap_add_extent_hole_delay(ip, whichfork, lastx, got);
+	xfs_bmap_add_extent_hole_delay(ip, whichfork, icur, got);
 
 	/*
 	 * Tag the inode if blocks were preallocated. Note that COW fork
···
 	if (bma->wasdel) {
 		bma->length = (xfs_extlen_t)bma->got.br_blockcount;
 		bma->offset = bma->got.br_startoff;
-		if (bma->idx) {
-			xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx - 1),
-					 &bma->prev);
-		}
+		xfs_iext_peek_prev_extent(ifp, &bma->icur, &bma->prev);
 	} else {
 		bma->length = XFS_FILBLKS_MIN(bma->length, MAXEXTLEN);
 		if (!bma->eof)
···
 		error = xfs_bmap_add_extent_delay_real(bma, whichfork);
 	else
 		error = xfs_bmap_add_extent_hole_real(bma->tp, bma->ip,
-				whichfork, &bma->idx, &bma->cur, &bma->got,
+				whichfork, &bma->icur, &bma->cur, &bma->got,
 				bma->firstblock, bma->dfops, &bma->logflags);
 
 	bma->logflags |= tmp_logflags;
···
 	 * or xfs_bmap_add_extent_hole_real might have merged it into one of
 	 * the neighbouring ones.
 	 */
-	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx), &bma->got);
+	xfs_iext_get_extent(ifp, &bma->icur, &bma->got);
 
 	ASSERT(bma->got.br_startoff <= bma->offset);
 	ASSERT(bma->got.br_startoff + bma->got.br_blockcount >=
···
 	}
 
 	error = xfs_bmap_add_extent_unwritten_real(bma->tp, bma->ip, whichfork,
-			&bma->idx, &bma->cur, mval, bma->firstblock, bma->dfops,
-			&tmp_logflags);
+			&bma->icur, &bma->cur, mval, bma->firstblock,
+			bma->dfops, &tmp_logflags);
 	/*
 	 * Log the inode core unconditionally in the unwritten extent conversion
 	 * path because the conversion might not have done so (e.g., if the
···
 	 * xfs_bmap_add_extent_unwritten_real might have merged it into one
 	 * of the neighbouring ones.
 	 */
-	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, bma->idx), &bma->got);
+	xfs_iext_get_extent(ifp, &bma->icur, &bma->got);
 
 	/*
 	 * We may have combined previously unwritten space with written space,
···
 	end = bno + len;
 	obno = bno;
 
-	if (!xfs_iext_lookup_extent(ip, ifp, bno, &bma.idx, &bma.got))
+	if (!xfs_iext_lookup_extent(ip, ifp, bno, &bma.icur, &bma.got))
 		eof = true;
-	if (!xfs_iext_get_extent(ifp, bma.idx - 1, &bma.prev))
+	if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
 		bma.prev.br_startoff = NULLFILEOFF;
 	bma.tp = tp;
 	bma.ip = ip;
···
 		 * First, deal with the hole before the allocated space
 		 * that we found, if any.
 		 */
-		if (need_alloc || wasdelay) {
+		if ((need_alloc || wasdelay) &&
+		    !(flags & XFS_BMAPI_CONVERT_ONLY)) {
 			bma.eof = eof;
 			bma.conv = !!(flags & XFS_BMAPI_CONVERT);
 			bma.wasdel = wasdelay;
···
 
 		/* Else go on to the next record. */
 		bma.prev = bma.got;
-		if (!xfs_iext_get_extent(ifp, ++bma.idx, &bma.got))
+		if (!xfs_iext_next_extent(ifp, &bma.icur, &bma.got))
 			eof = true;
 	}
 	*nmap = n;
···
 	struct xfs_btree_cur	*cur = NULL;
 	xfs_fsblock_t		firstblock = NULLFSBLOCK;
 	struct xfs_bmbt_irec	got;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	icur;
 	int			logflags = 0, error;
 
 	ASSERT(len > 0);
···
 			return error;
 	}
 
-	if (xfs_iext_lookup_extent(ip, ifp, bno, &idx, &got)) {
+	if (xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
 		/* make sure we only reflink into a hole. */
 		ASSERT(got.br_startoff > bno);
 		ASSERT(got.br_startoff - bno >= len);
···
 	got.br_blockcount = len;
 	got.br_state = XFS_EXT_NORM;
 
-	error = xfs_bmap_add_extent_hole_real(tp, ip, XFS_DATA_FORK, &idx, &cur,
-			&got, &firstblock, dfops, &logflags);
+	error = xfs_bmap_add_extent_hole_real(tp, ip, XFS_DATA_FORK, &icur,
+			&cur, &got, &firstblock, dfops, &logflags);
 	if (error)
 		goto error0;
 
···
 xfs_bmap_del_extent_delay(
 	struct xfs_inode	*ip,
 	int			whichfork,
-	xfs_extnum_t		*idx,
+	struct xfs_iext_cursor	*icur,
 	struct xfs_bmbt_irec	*got,
 	struct xfs_bmbt_irec	*del)
 {
···
 	int64_t			da_old, da_new, da_diff = 0;
 	xfs_fileoff_t		del_endoff, got_endoff;
 	xfs_filblks_t		got_indlen, new_indlen, stolen;
-	int			error = 0, state = 0;
+	int			state = xfs_bmap_fork_to_state(whichfork);
+	int			error = 0;
 	bool			isrt;
 
 	XFS_STATS_INC(mp, xs_del_exlist);
···
 	da_old = startblockval(got->br_startblock);
 	da_new = 0;
 
-	ASSERT(*idx >= 0);
-	ASSERT(*idx <= xfs_iext_count(ifp));
 	ASSERT(del->br_blockcount > 0);
 	ASSERT(got->br_startoff <= del->br_startoff);
 	ASSERT(got_endoff >= del_endoff);
···
 		return error;
 	ip->i_delayed_blks -= del->br_blockcount;
 
-	if (whichfork == XFS_COW_FORK)
-		state |= BMAP_COWFORK;
-
 	if (got->br_startoff == del->br_startoff)
-		state |= BMAP_LEFT_CONTIG;
+		state |= BMAP_LEFT_FILLING;
 	if (got_endoff == del_endoff)
-		state |= BMAP_RIGHT_CONTIG;
+		state |= BMAP_RIGHT_FILLING;
 
-	switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
-	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+	switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
 		/*
 		 * Matches the whole extent.  Delete the entry.
 		 */
-		xfs_iext_remove(ip, *idx, 1, state);
-		--*idx;
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_prev(ifp, icur);
 		break;
-	case BMAP_LEFT_CONTIG:
+	case BMAP_LEFT_FILLING:
 		/*
 		 * Deleting the first part of the extent.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
 		got->br_startoff = del_endoff;
 		got->br_blockcount -= del->br_blockcount;
 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip,
 				got->br_blockcount), da_old);
 		got->br_startblock = nullstartblock((int)da_new);
-		xfs_iext_update_extent(ifp, *idx, got);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		xfs_iext_update_extent(ip, state, icur, got);
 		break;
-	case BMAP_RIGHT_CONTIG:
+	case BMAP_RIGHT_FILLING:
 		/*
 		 * Deleting the last part of the extent.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
 		got->br_blockcount = got->br_blockcount - del->br_blockcount;
 		da_new = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip,
 				got->br_blockcount), da_old);
 		got->br_startblock = nullstartblock((int)da_new);
-		xfs_iext_update_extent(ifp, *idx, got);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		xfs_iext_update_extent(ip, state, icur, got);
 		break;
 	case 0:
 		/*
···
 		 * Warn if either of the new indlen reservations is zero as this
 		 * can lead to delalloc problems.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-
 		got->br_blockcount = del->br_startoff - got->br_startoff;
 		got_indlen = xfs_bmap_worst_indlen(ip, got->br_blockcount);
 
···
 						       del->br_blockcount);
 
 		got->br_startblock = nullstartblock((int)got_indlen);
-		xfs_iext_update_extent(ifp, *idx, got);
-		trace_xfs_bmap_post_update(ip, *idx, 0, _THIS_IP_);
 
 		new.br_startoff = del_endoff;
 		new.br_state = got->br_state;
 		new.br_startblock = nullstartblock((int)new_indlen);
 
-		++*idx;
-		xfs_iext_insert(ip, *idx, 1, &new, state);
+		xfs_iext_update_extent(ip, state, icur, got);
+		xfs_iext_next(ifp, icur);
+		xfs_iext_insert(ip, icur, &new, state);
 
 		da_new = got_indlen + new_indlen - stolen;
 		del->br_blockcount -= stolen;
···
 void
 xfs_bmap_del_extent_cow(
 	struct xfs_inode	*ip,
-	xfs_extnum_t		*idx,
+	struct xfs_iext_cursor	*icur,
 	struct xfs_bmbt_irec	*got,
 	struct xfs_bmbt_irec	*del)
 {
···
 	del_endoff = del->br_startoff + del->br_blockcount;
 	got_endoff = got->br_startoff + got->br_blockcount;
 
-	ASSERT(*idx >= 0);
-	ASSERT(*idx <= xfs_iext_count(ifp));
 	ASSERT(del->br_blockcount > 0);
 	ASSERT(got->br_startoff <= del->br_startoff);
 	ASSERT(got_endoff >= del_endoff);
 	ASSERT(!isnullstartblock(got->br_startblock));
 
 	if (got->br_startoff == del->br_startoff)
-		state |= BMAP_LEFT_CONTIG;
+		state |= BMAP_LEFT_FILLING;
 	if (got_endoff == del_endoff)
-		state |= BMAP_RIGHT_CONTIG;
+		state |= BMAP_RIGHT_FILLING;
 
-	switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) {
-	case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG:
+	switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
 		/*
 		 * Matches the whole extent.  Delete the entry.
 		 */
-		xfs_iext_remove(ip, *idx, 1, state);
-		--*idx;
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_prev(ifp, icur);
 		break;
-	case BMAP_LEFT_CONTIG:
+	case BMAP_LEFT_FILLING:
 		/*
 		 * Deleting the first part of the extent.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
 		got->br_startoff = del_endoff;
 		got->br_blockcount -= del->br_blockcount;
 		got->br_startblock = del->br_startblock + del->br_blockcount;
-		xfs_iext_update_extent(ifp, *idx, got);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		xfs_iext_update_extent(ip, state, icur, got);
 		break;
-	case BMAP_RIGHT_CONTIG:
+	case BMAP_RIGHT_FILLING:
 		/*
 		 * Deleting the last part of the extent.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
 		got->br_blockcount -= del->br_blockcount;
-		xfs_iext_update_extent(ifp, *idx, got);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		xfs_iext_update_extent(ip, state, icur, got);
 		break;
 	case 0:
 		/*
 		 * Deleting the middle of the extent.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
 		got->br_blockcount = del->br_startoff - got->br_startoff;
-		xfs_iext_update_extent(ifp, *idx, got);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
 
 		new.br_startoff = del_endoff;
 		new.br_blockcount = got_endoff - del_endoff;
 		new.br_state = got->br_state;
 		new.br_startblock = del->br_startblock + del->br_blockcount;
 
-		++*idx;
-		xfs_iext_insert(ip, *idx, 1, &new, state);
+		xfs_iext_update_extent(ip, state, icur, got);
+		xfs_iext_next(ifp, icur);
+		xfs_iext_insert(ip, icur, &new, state);
 		break;
 	}
 }
 
 /*
  * Called by xfs_bmapi to update file extent records and the btree
- * after removing space (or undoing a delayed allocation).
+ * after removing space.
  */
 STATIC int				/* error */
-xfs_bmap_del_extent(
+xfs_bmap_del_extent_real(
 	xfs_inode_t		*ip,	/* incore inode pointer */
 	xfs_trans_t		*tp,	/* current transaction pointer */
-	xfs_extnum_t		*idx,	/* extent number to update/delete */
+	struct xfs_iext_cursor	*icur,
 	struct xfs_defer_ops	*dfops,	/* list of extents to be freed */
 	xfs_btree_cur_t		*cur,	/* if null, not a btree */
 	xfs_bmbt_irec_t		*del,	/* data to remove from extents */
···
 	int			whichfork, /* data or attr fork */
 	int			bflags)	/* bmapi flags */
 {
-	xfs_filblks_t		da_new;	/* new delay-alloc indirect blocks */
-	xfs_filblks_t		da_old;	/* old delay-alloc indirect blocks */
 	xfs_fsblock_t		del_endblock=0;	/* first block past del */
 	xfs_fileoff_t		del_endoff;	/* first offset past del */
-	int			delay;	/* current block is delayed allocated */
 	int			do_fx;	/* free extent at end of routine */
-	xfs_bmbt_rec_host_t	*ep;	/* current extent entry pointer */
 	int			error;	/* error return value */
-	int			flags;	/* inode logging flags */
-	xfs_bmbt_irec_t		got;	/* current extent entry */
+	int			flags = 0;/* inode logging flags */
+	struct xfs_bmbt_irec	got;	/* current extent entry */
 	xfs_fileoff_t		got_endoff;	/* first offset past got */
 	int			i;	/* temp state */
 	xfs_ifork_t		*ifp;	/* inode fork pointer */
···
 	xfs_bmbt_irec_t		new;	/* new record to be inserted */
 	/* REFERENCED */
 	uint			qfield;	/* quota field to update */
-	xfs_filblks_t		temp;	/* for indirect length calculations */
-	xfs_filblks_t		temp2;	/* for indirect length calculations */
-	int			state = 0;
+	int			state = xfs_bmap_fork_to_state(whichfork);
+	struct xfs_bmbt_irec	old;
 
 	mp = ip->i_mount;
 	XFS_STATS_INC(mp, xs_del_exlist);
 
-	if (whichfork == XFS_ATTR_FORK)
-		state |= BMAP_ATTRFORK;
-	else if (whichfork == XFS_COW_FORK)
-		state |= BMAP_COWFORK;
-
 	ifp = XFS_IFORK_PTR(ip, whichfork);
-	ASSERT((*idx >= 0) && (*idx < xfs_iext_count(ifp)));
 	ASSERT(del->br_blockcount > 0);
-	ep = xfs_iext_get_ext(ifp, *idx);
-	xfs_bmbt_get_all(ep, &got);
+	xfs_iext_get_extent(ifp, icur, &got);
 	ASSERT(got.br_startoff <= del->br_startoff);
 	del_endoff = del->br_startoff + del->br_blockcount;
 	got_endoff = got.br_startoff + got.br_blockcount;
 	ASSERT(got_endoff >= del_endoff);
-	delay = isnullstartblock(got.br_startblock);
-	ASSERT(isnullstartblock(del->br_startblock) == delay);
-	flags = 0;
+	ASSERT(!isnullstartblock(got.br_startblock));
 	qfield = 0;
 	error = 0;
-	/*
-	 * If deleting a real allocation, must free up the disk space.
-	 */
-	if (!delay) {
-		flags = XFS_ILOG_CORE;
-		/*
-		 * Realtime allocation.  Free it and record di_nblocks update.
-		 */
-		if (whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip)) {
-			xfs_fsblock_t	bno;
-			xfs_filblks_t	len;
 
-			ASSERT(do_mod(del->br_blockcount,
-				      mp->m_sb.sb_rextsize) == 0);
-			ASSERT(do_mod(del->br_startblock,
-				      mp->m_sb.sb_rextsize) == 0);
-			bno = del->br_startblock;
-			len = del->br_blockcount;
-			do_div(bno, mp->m_sb.sb_rextsize);
-			do_div(len, mp->m_sb.sb_rextsize);
-			error = xfs_rtfree_extent(tp, bno, (xfs_extlen_t)len);
-			if (error)
-				goto done;
-			do_fx = 0;
-			nblks = len * mp->m_sb.sb_rextsize;
-			qfield = XFS_TRANS_DQ_RTBCOUNT;
-		}
-		/*
-		 * Ordinary allocation.
-		 */
-		else {
-			do_fx = 1;
-			nblks = del->br_blockcount;
-			qfield = XFS_TRANS_DQ_BCOUNT;
-		}
-		/*
-		 * Set up del_endblock and cur for later.
-		 */
-		del_endblock = del->br_startblock + del->br_blockcount;
-		if (cur) {
-			if ((error = xfs_bmbt_lookup_eq(cur, got.br_startoff,
-					got.br_startblock, got.br_blockcount,
-					&i)))
-				goto done;
-			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-		}
-		da_old = da_new = 0;
-	} else {
-		da_old = startblockval(got.br_startblock);
-		da_new = 0;
-		nblks = 0;
+	/*
+	 * If it's the case where the directory code is running with no block
+	 * reservation, and the deleted block is in the middle of its extent,
+	 * and the resulting insert of an extent would cause transformation to
+	 * btree format, then reject it.  The calling code will then swap blocks
+	 * around instead.  We have to do this now, rather than waiting for the
+	 * conversion to btree format, since the transaction will be dirty then.
+	 */
+	if (tp->t_blk_res == 0 &&
+	    XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS &&
+	    XFS_IFORK_NEXTENTS(ip, whichfork) >=
+			XFS_IFORK_MAXEXT(ip, whichfork) &&
+	    del->br_startoff > got.br_startoff && del_endoff < got_endoff)
+		return -ENOSPC;
+
+	flags = XFS_ILOG_CORE;
+	if (whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip)) {
+		xfs_fsblock_t	bno;
+		xfs_filblks_t	len;
+
+		ASSERT(do_mod(del->br_blockcount, mp->m_sb.sb_rextsize) == 0);
+		ASSERT(do_mod(del->br_startblock, mp->m_sb.sb_rextsize) == 0);
+		bno = del->br_startblock;
+		len = del->br_blockcount;
+		do_div(bno, mp->m_sb.sb_rextsize);
+		do_div(len, mp->m_sb.sb_rextsize);
+		error = xfs_rtfree_extent(tp, bno, (xfs_extlen_t)len);
+		if (error)
+			goto done;
 		do_fx = 0;
+		nblks = len * mp->m_sb.sb_rextsize;
+		qfield = XFS_TRANS_DQ_RTBCOUNT;
+	} else {
+		do_fx = 1;
+		nblks = del->br_blockcount;
+		qfield = XFS_TRANS_DQ_BCOUNT;
 	}
 
-	/*
-	 * Set flag value to use in switch statement.
-	 * Left-contig is 2, right-contig is 1.
-	 */
-	switch (((got.br_startoff == del->br_startoff) << 1) |
-		(got_endoff == del_endoff)) {
-	case 3:
+	del_endblock = del->br_startblock + del->br_blockcount;
+	if (cur) {
+		error = xfs_bmbt_lookup_eq(cur, &got, &i);
+		if (error)
+			goto done;
+		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+	}
+
+	if (got.br_startoff == del->br_startoff)
+		state |= BMAP_LEFT_FILLING;
+	if (got_endoff == del_endoff)
+		state |= BMAP_RIGHT_FILLING;
+
+	switch (state & (BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING)) {
+	case BMAP_LEFT_FILLING | BMAP_RIGHT_FILLING:
 		/*
 		 * Matches the whole extent.  Delete the entry.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_iext_remove(ip, *idx, 1,
-				whichfork == XFS_ATTR_FORK ? BMAP_ATTRFORK : 0);
-		--*idx;
-		if (delay)
-			break;
-
+		xfs_iext_remove(ip, icur, state);
+		xfs_iext_prev(ifp, icur);
 		XFS_IFORK_NEXT_SET(ip, whichfork,
 			XFS_IFORK_NEXTENTS(ip, whichfork) - 1);
 		flags |= XFS_ILOG_CORE;
···
 			goto done;
 		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
 		break;
-
-	case 2:
+	case BMAP_LEFT_FILLING:
 		/*
 		 * Deleting the first part of the extent.
 		 */
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_startoff(ep, del_endoff);
-		temp = got.br_blockcount - del->br_blockcount;
-		xfs_bmbt_set_blockcount(ep, temp);
-		if (delay) {
-			temp = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
-				da_old);
-			xfs_bmbt_set_startblock(ep, nullstartblock((int)temp));
-			trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
-			da_new = temp;
-			break;
-		}
-		xfs_bmbt_set_startblock(ep, del_endblock);
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		got.br_startoff = del_endoff;
+		got.br_startblock = del_endblock;
+		got.br_blockcount -= del->br_blockcount;
+		xfs_iext_update_extent(ip, state, icur, &got);
 		if (!cur) {
 			flags |= xfs_ilog_fext(whichfork);
 			break;
 		}
-		if ((error = xfs_bmbt_update(cur, del_endoff, del_endblock,
-				got.br_blockcount - del->br_blockcount,
-				got.br_state)))
+		error = xfs_bmbt_update(cur, &got);
+		if (error)
 			goto done;
 		break;
-
-	case 1:
+	case BMAP_RIGHT_FILLING:
 		/*
 		 * Deleting the last part of the extent.
 		 */
-		temp = got.br_blockcount - del->br_blockcount;
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep, temp);
-		if (delay) {
-			temp = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp),
-				da_old);
-			xfs_bmbt_set_startblock(ep, nullstartblock((int)temp));
-			trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
-			da_new = temp;
-			break;
-		}
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
+		got.br_blockcount -= del->br_blockcount;
+		xfs_iext_update_extent(ip, state, icur, &got);
 		if (!cur) {
 			flags |= xfs_ilog_fext(whichfork);
 			break;
 		}
-		if ((error = xfs_bmbt_update(cur, got.br_startoff,
-				got.br_startblock,
-				got.br_blockcount - del->br_blockcount,
-				got.br_state)))
+		error = xfs_bmbt_update(cur, &got);
+		if (error)
 			goto done;
 		break;
-
 	case 0:
 		/*
 		 * Deleting the middle of the extent.
 		 */
-		temp = del->br_startoff - got.br_startoff;
-		trace_xfs_bmap_pre_update(ip, *idx, state, _THIS_IP_);
-		xfs_bmbt_set_blockcount(ep, temp);
+		old = got;
+
+		got.br_blockcount = del->br_startoff - got.br_startoff;
+		xfs_iext_update_extent(ip, state, icur, &got);
+
 		new.br_startoff = del_endoff;
-		temp2 = got_endoff - del_endoff;
-		new.br_blockcount = temp2;
+		new.br_blockcount = got_endoff - del_endoff;
 		new.br_state = got.br_state;
-		if (!delay) {
-			new.br_startblock = del_endblock;
-			flags |= XFS_ILOG_CORE;
-			if (cur) {
-				if ((error = xfs_bmbt_update(cur,
-						got.br_startoff,
-						got.br_startblock, temp,
-						got.br_state)))
+		new.br_startblock = del_endblock;
+
+		flags |= XFS_ILOG_CORE;
+		if (cur) {
+			error = xfs_bmbt_update(cur, &got);
+			if (error)
+				goto done;
+			error = xfs_btree_increment(cur, 0, &i);
+			if (error)
+				goto done;
+			cur->bc_rec.b = new;
+			error = xfs_btree_insert(cur, &i);
+			if (error && error != -ENOSPC)
+				goto done;
+			/*
+			 * If get no-space back from btree insert, it tried a
+			 * split, and we have a zero block reservation.  Fix up
+			 * our state and return the error.
+			 */
+			if (error == -ENOSPC) {
+				/*
+				 * Reset the cursor, don't trust it after any
+				 * insert operation.
+				 */
+				error = xfs_bmbt_lookup_eq(cur, &got, &i);
+				if (error)
 					goto done;
-				if ((error = xfs_btree_increment(cur, 0, &i)))
-					goto done;
-				cur->bc_rec.b = new;
-				error = xfs_btree_insert(cur, &i);
-				if (error && error != -ENOSPC)
+				XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+				/*
+				 * Update the btree record back
+				 * to the original value.
+				 */
+				error = xfs_bmbt_update(cur, &old);
+				if (error)
 					goto done;
 				/*
-				 * If get no-space back from btree insert,
-				 * it tried a split, and we have a zero
-				 * block reservation.
-				 * Fix up our state and return the error.
+				 * Reset the extent record back
+				 * to the original value.
 				 */
-				if (error == -ENOSPC) {
-					/*
-					 * Reset the cursor, don't trust
-					 * it after any insert operation.
-					 */
-					if ((error = xfs_bmbt_lookup_eq(cur,
-							got.br_startoff,
-							got.br_startblock,
-							temp, &i)))
-						goto done;
-					XFS_WANT_CORRUPTED_GOTO(mp,
-								i == 1, done);
-					/*
-					 * Update the btree record back
-					 * to the original value.
-					 */
-					if ((error = xfs_bmbt_update(cur,
-							got.br_startoff,
-							got.br_startblock,
-							got.br_blockcount,
-							got.br_state)))
-						goto done;
-					/*
-					 * Reset the extent record back
-					 * to the original value.
-					 */
-					xfs_bmbt_set_blockcount(ep,
-						got.br_blockcount);
-					flags = 0;
-					error = -ENOSPC;
-					goto done;
-				}
-				XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
-			} else
-				flags |= xfs_ilog_fext(whichfork);
-			XFS_IFORK_NEXT_SET(ip, whichfork,
-				XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
-		} else {
-			xfs_filblks_t	stolen;
-			ASSERT(whichfork == XFS_DATA_FORK);
-
-			/*
-			 * Distribute the original indlen reservation across the
-			 * two new extents. Steal blocks from the deleted extent
-			 * if necessary. Stealing blocks simply fudges the
-			 * fdblocks accounting in xfs_bunmapi().
-			 */
-			temp = xfs_bmap_worst_indlen(ip, got.br_blockcount);
-			temp2 = xfs_bmap_worst_indlen(ip, new.br_blockcount);
-			stolen = xfs_bmap_split_indlen(da_old, &temp, &temp2,
-						       del->br_blockcount);
-			da_new = temp + temp2 - stolen;
-			del->br_blockcount -= stolen;
-
-			/*
-			 * Set the reservation for each extent. Warn if either
-			 * is zero as this can lead to delalloc problems.
-			 */
-			WARN_ON_ONCE(!temp || !temp2);
-			xfs_bmbt_set_startblock(ep, nullstartblock((int)temp));
-			new.br_startblock = nullstartblock((int)temp2);
-		}
-		trace_xfs_bmap_post_update(ip, *idx, state, _THIS_IP_);
-		xfs_iext_insert(ip, *idx + 1, 1, &new, state);
-		++*idx;
+				xfs_iext_update_extent(ip, state, icur, &old);
+				flags = 0;
+				error = -ENOSPC;
+				goto done;
+			}
+			XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+		} else
+			flags |= xfs_ilog_fext(whichfork);
+		XFS_IFORK_NEXT_SET(ip, whichfork,
+			XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
+		xfs_iext_next(ifp, icur);
+		xfs_iext_insert(ip, icur, &new, state);
 		break;
 	}
 
 	/* remove reverse mapping */
-	if (!delay) {
-		error = xfs_rmap_unmap_extent(mp, dfops, ip, whichfork, del);
-		if (error)
-			goto done;
-	}
+	error = xfs_rmap_unmap_extent(mp, dfops, ip, whichfork, del);
+	if (error)
+		goto done;
 
 	/*
 	 * If we need to, add to list of extents to delete.
···
 	if (qfield && !(bflags & XFS_BMAPI_REMAP))
 		xfs_trans_mod_dquot_byino(tp, ip, qfield, (long)-nblks);
 
-	/*
-	 * Account for change in delayed indirect blocks.
-	 * Nothing to do for disk quota accounting here.
-	 */
-	ASSERT(da_old >= da_new);
-	if (da_old > da_new)
-		xfs_mod_fdblocks(mp, (int64_t)(da_old - da_new), false);
 done:
 	*logflagsp = flags;
 	return error;
···
 __xfs_bunmapi(
 	xfs_trans_t		*tp,		/* transaction pointer */
 	struct xfs_inode	*ip,		/* incore inode */
-	xfs_fileoff_t		bno,		/* starting offset to unmap */
+	xfs_fileoff_t		start,		/* first file offset deleted */
 	xfs_filblks_t		*rlen,		/* i/o: amount remaining */
 	int			flags,		/* misc flags */
 	xfs_extnum_t		nexts,		/* number of extents max */
···
 	xfs_bmbt_irec_t		got;		/* current extent record */
 	xfs_ifork_t		*ifp;		/* inode fork pointer */
 	int			isrt;		/* freeing in rt area */
-	xfs_extnum_t		lastx;		/* last extent index used */
 	int			logflags;	/* transaction logging flags */
 	xfs_extlen_t		mod;		/* rt extent offset */
 	xfs_mount_t		*mp;		/* mount structure */
-	xfs_fileoff_t		start;		/* first file offset deleted */
 	int			tmp_logflags;	/* partial logging flags */
 	int			wasdel;		/* was a delayed alloc extent */
 	int			whichfork;	/* data or attribute fork */
···
 	xfs_filblks_t		len = *rlen;	/* length to unmap in file */
 	xfs_fileoff_t		max_len;
 	xfs_agnumber_t		prev_agno = NULLAGNUMBER, agno;
+	xfs_fileoff_t		end;
+	struct xfs_iext_cursor	icur;
+	bool			done = false;
 
-	trace_xfs_bunmap(ip, bno, len, flags, _RET_IP_);
+	trace_xfs_bunmap(ip, start, len, flags, _RET_IP_);
 
 	whichfork = xfs_bmapi_whichfork(flags);
 	ASSERT(whichfork != XFS_COW_FORK);
···
 	}
 	XFS_STATS_INC(mp, xs_blk_unmap);
 	isrt = (whichfork == XFS_DATA_FORK) && XFS_IS_REALTIME_INODE(ip);
-	start = bno;
-	bno = start + len - 1;
+	end = start + len;
 
-	/*
-	 * Check to see if the given block number is past the end of the
-	 * file, back up to the last block if so...
-	 */
-	if (!xfs_iext_lookup_extent(ip, ifp, bno, &lastx, &got)) {
-		ASSERT(lastx > 0);
-		xfs_iext_get_extent(ifp, --lastx, &got);
-		bno = got.br_startoff + got.br_blockcount - 1;
+	if (!xfs_iext_lookup_extent_before(ip, ifp, &end, &icur, &got)) {
+		*rlen = 0;
+		return 0;
 	}
+	end--;
 
 	logflags = 0;
 	if (ifp->if_flags & XFS_IFBROOT) {
···
 	}
 
 	extno = 0;
-	while (bno != (xfs_fileoff_t)-1 && bno >= start && lastx >= 0 &&
+	while (end != (xfs_fileoff_t)-1 && end >= start &&
 	       (nexts == 0 || extno < nexts) && max_len > 0) {
 		/*
-		 * Is the found extent after a hole in which bno lives?
+		 * Is the found extent after a hole in which end lives?
 		 * Just back up to the previous extent, if so.
 		 */
-		if (got.br_startoff > bno) {
-			if (--lastx < 0)
-				break;
-			xfs_iext_get_extent(ifp, lastx, &got);
+		if (got.br_startoff > end &&
+		    !xfs_iext_prev_extent(ifp, &icur, &got)) {
+			done = true;
+			break;
 		}
 		/*
 		 * Is the last block of this extent before the range
 		 * we're supposed to delete?  If so, we're done.
 		 */
-		bno = XFS_FILEOFF_MIN(bno,
+		end = XFS_FILEOFF_MIN(end,
 			got.br_startoff + got.br_blockcount - 1);
-		if (bno < start)
+		if (end < start)
 			break;
 		/*
 		 * Then deal with the (possibly delayed) allocated space
···
 			if (!wasdel)
 				del.br_startblock += start - got.br_startoff;
 		}
-		if (del.br_startoff + del.br_blockcount > bno + 1)
-			del.br_blockcount = bno + 1 - del.br_startoff;
+		if (del.br_startoff + del.br_blockcount > end + 1)
+			del.br_blockcount = end + 1 - del.br_startoff;
 
 		/* How much can we safely unmap? */
 		if (max_len < del.br_blockcount) {
···
 				 * This piece is unwritten, or we're not
 				 * using unwritten extents.  Skip over it.
 				 */
-				ASSERT(bno >= mod);
-				bno -= mod > del.br_blockcount ?
+				ASSERT(end >= mod);
+				end -= mod > del.br_blockcount ?
 					del.br_blockcount : mod;
-				if (bno < got.br_startoff) {
-					if (--lastx >= 0)
-						xfs_bmbt_get_all(xfs_iext_get_ext(
-							ifp, lastx), &got);
+				if (end < got.br_startoff &&
+				    !xfs_iext_prev_extent(ifp, &icur, &got)) {
+					done = true;
+					break;
 				}
 				continue;
 			}
···
 			}
 			del.br_state = XFS_EXT_UNWRITTEN;
 			error = xfs_bmap_add_extent_unwritten_real(tp, ip,
-					whichfork, &lastx, &cur, &del,
+					whichfork, &icur, &cur, &del,
 					firstblock, dfops, &logflags);
 			if (error)
 				goto error0;
···
 				 * Can't make it unwritten.  There isn't
 				 * a full extent here so just skip it.
 				 */
-				ASSERT(bno >= del.br_blockcount);
-				bno -= del.br_blockcount;
-				if (got.br_startoff > bno && --lastx >= 0)
-					xfs_iext_get_extent(ifp, lastx, &got);
+				ASSERT(end >= del.br_blockcount);
+				end -= del.br_blockcount;
+				if (got.br_startoff > end &&
+				    !xfs_iext_prev_extent(ifp, &icur, &got)) {
+					done = true;
+					break;
+				}
 				continue;
 			} else if (del.br_state == XFS_EXT_UNWRITTEN) {
 				struct xfs_bmbt_irec	prev;
···
 				 * Unwrite the killed part of that one and
 				 * try again.
 				 */
-				ASSERT(lastx > 0);
-				xfs_iext_get_extent(ifp, lastx - 1, &prev);
+				if (!xfs_iext_prev_extent(ifp, &icur, &prev))
+					ASSERT(0);
 				ASSERT(prev.br_state == XFS_EXT_NORM);
 				ASSERT(!isnullstartblock(prev.br_startblock));
 				ASSERT(del.br_startblock ==
···
 					prev.br_startoff = start;
 				}
 				prev.br_state = XFS_EXT_UNWRITTEN;
-				lastx--;
 				error = xfs_bmap_add_extent_unwritten_real(tp,
-						ip, whichfork, &lastx, &cur,
+						ip, whichfork, &icur, &cur,
 						&prev, firstblock, dfops,
 						&logflags);
 				if (error)
···
 				ASSERT(del.br_state == XFS_EXT_NORM);
 				del.br_state = XFS_EXT_UNWRITTEN;
 				error = xfs_bmap_add_extent_unwritten_real(tp,
-						ip, whichfork, &lastx, &cur,
+						ip, whichfork, &icur, &cur,
 						&del, firstblock, dfops,
 						&logflags);
 				if (error)
···
 			}
 		}
 
-		/*
-		 * If it's the case where the directory code is running
-		 * with no block reservation, and the deleted block is in
-		 * the middle of its extent, and the resulting insert
-		 * of an extent would cause transformation to btree format,
-		 * then reject it.  The calling code will then swap
-		 * blocks around instead.
-		 * We have to do this now, rather than waiting for the
-		 * conversion to btree format, since the transaction
-		 * will be dirty.
-		 */
-		if (!wasdel && tp->t_blk_res == 0 &&
-		    XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_EXTENTS &&
-		    XFS_IFORK_NEXTENTS(ip, whichfork) >= /* Note the >= */
-			XFS_IFORK_MAXEXT(ip, whichfork) &&
-		    del.br_startoff > got.br_startoff &&
-		    del.br_startoff + del.br_blockcount <
-		    got.br_startoff + got.br_blockcount) {
-			error = -ENOSPC;
-			goto error0;
+		if (wasdel) {
+			error = xfs_bmap_del_extent_delay(ip, whichfork, &icur,
+					&got, &del);
+		} else {
+			error = xfs_bmap_del_extent_real(ip, tp, &icur, dfops,
+					cur, &del, &tmp_logflags, whichfork,
+					flags);
+			logflags |= tmp_logflags;
 		}
 
-		/*
-		 * Unreserve quota and update realtime free space, if
-		 * appropriate. If delayed allocation, update the inode delalloc
-		 * counter now and wait to update the sb counters as
-		 * xfs_bmap_del_extent() might need to borrow some blocks.
-		 */
-		if (wasdel) {
-			ASSERT(startblockval(del.br_startblock) > 0);
-			if (isrt) {
-				xfs_filblks_t rtexts;
-
-				rtexts = XFS_FSB_TO_B(mp, del.br_blockcount);
-				do_div(rtexts, mp->m_sb.sb_rextsize);
-				xfs_mod_frextents(mp, (int64_t)rtexts);
-				(void)xfs_trans_reserve_quota_nblks(NULL,
-					ip, -((long)del.br_blockcount), 0,
-					XFS_QMOPT_RES_RTBLKS);
-			} else {
-				(void)xfs_trans_reserve_quota_nblks(NULL,
-					ip, -((long)del.br_blockcount), 0,
-					XFS_QMOPT_RES_REGBLKS);
-			}
-			ip->i_delayed_blks -= del.br_blockcount;
-			if (cur)
-				cur->bc_private.b.flags |=
-					XFS_BTCUR_BPRV_WASDEL;
-		} else if (cur)
-			cur->bc_private.b.flags &= ~XFS_BTCUR_BPRV_WASDEL;
-
-		error = xfs_bmap_del_extent(ip, tp, &lastx, dfops, cur, &del,
-				&tmp_logflags, whichfork, flags);
-		logflags |= tmp_logflags;
 		if (error)
 			goto error0;
 
-		if (!isrt && wasdel)
-			xfs_mod_fdblocks(mp, (int64_t)del.br_blockcount, false);
-
 		max_len -= del.br_blockcount;
-		bno = del.br_startoff - 1;
+		end = del.br_startoff - 1;
 nodelete:
 		/*
 		 * If not done go on to the next (previous) record.
 		 */
-		if (bno != (xfs_fileoff_t)-1 && bno >= start) {
-			if (lastx >= 0) {
-				xfs_iext_get_extent(ifp, lastx, &got);
-				if (got.br_startoff > bno && --lastx >= 0)
-					xfs_iext_get_extent(ifp, lastx, &got);
+		if (end != (xfs_fileoff_t)-1 && end >= start) {
+			if (!xfs_iext_get_extent(ifp, &icur, &got) ||
+			    (got.br_startoff > end &&
+			     !xfs_iext_prev_extent(ifp, &icur, &got))) {
+				done = true;
+				break;
 			}
 			extno++;
 		}
 	}
-	if (bno == (xfs_fileoff_t)-1 || bno < start || lastx < 0)
+	if (done || end == (xfs_fileoff_t)-1 || end < start)
 		*rlen = 0;
 	else
-		*rlen = bno - start + 1;
+		*rlen = end - start + 1;
 
 	/*
 	 * Convert to a btree if necessary.
···
 	struct xfs_inode		*ip,
 	int				whichfork,
 	xfs_fileoff_t			shift,		/* shift fsb */
-	int				current_ext,	/* idx of gotp */
+	struct xfs_iext_cursor		*icur,
 	struct xfs_bmbt_irec		*got,		/* extent to shift */
 	struct xfs_bmbt_irec		*left,		/* preceding extent */
 	struct xfs_btree_cur		*cur,
 	int				*logflags,	/* output */
 	struct xfs_defer_ops		*dfops)
 {
-	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, whichfork);
 	struct xfs_bmbt_irec		new;
 	xfs_filblks_t			blockcount;
 	int				error, i;
···
 	}
 
 	/* lookup and remove the extent to merge */
-	error = xfs_bmbt_lookup_eq(cur, got->br_startoff, got->br_startblock,
-				   got->br_blockcount, &i);
+	error = xfs_bmbt_lookup_eq(cur, got, &i);
 	if (error)
 		return error;
 	XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
···
 	XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
 
 	/* lookup and update size of the previous extent */
-	error = xfs_bmbt_lookup_eq(cur, left->br_startoff, left->br_startblock,
-				   left->br_blockcount, &i);
+	error = xfs_bmbt_lookup_eq(cur, left, &i);
 	if (error)
 		return error;
 	XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
 
-	error = xfs_bmbt_update(cur, new.br_startoff, new.br_startblock,
-			        new.br_blockcount, new.br_state);
+	error = xfs_bmbt_update(cur, &new);
 	if (error)
 		return error;
 
 done:
-	xfs_iext_update_extent(ifp, current_ext - 1, &new);
-	xfs_iext_remove(ip, current_ext, 1, 0);
+	xfs_iext_remove(ip, icur, 0);
+	xfs_iext_prev(XFS_IFORK_PTR(ip, whichfork), icur);
+	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), icur,
+			&new);
 
 	/* update reverse mapping. rmap functions merge the rmaps for us */
 	error = xfs_rmap_unmap_extent(mp, dfops, ip, whichfork, got);
···
 	return xfs_rmap_map_extent(mp, dfops, ip, whichfork, &new);
 }
 
-/*
- * Shift a single extent.
- */
-STATIC int
-xfs_bmse_shift_one(
-	struct xfs_inode		*ip,
-	int				whichfork,
-	xfs_fileoff_t			offset_shift_fsb,
-	int				*current_ext,
-	struct xfs_bmbt_irec		*got,
-	struct xfs_btree_cur		*cur,
-	int				*logflags,
-	enum shift_direction		direction,
-	struct xfs_defer_ops		*dfops)
+static int
+xfs_bmap_shift_update_extent(
+	struct xfs_inode	*ip,
+	int			whichfork,
+	struct xfs_iext_cursor	*icur,
+	struct xfs_bmbt_irec	*got,
+	struct xfs_btree_cur	*cur,
+	int			*logflags,
+	struct xfs_defer_ops	*dfops,
+	xfs_fileoff_t		startoff)
 {
-	struct xfs_ifork		*ifp;
-	struct xfs_mount		*mp;
-	xfs_fileoff_t			startoff;
-	struct xfs_bmbt_irec		adj_irec, new;
-	int				error;
-	int				i;
-	int				total_extents;
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_bmbt_irec	prev = *got;
+	int			error, i;
 
-	mp = ip->i_mount;
-	ifp = XFS_IFORK_PTR(ip, whichfork);
-	total_extents = xfs_iext_count(ifp);
-
-	/* delalloc extents should be prevented by caller */
-	XFS_WANT_CORRUPTED_RETURN(mp, !isnullstartblock(got->br_startblock));
-
-	if (direction == SHIFT_LEFT) {
-		startoff = got->br_startoff - offset_shift_fsb;
-
-		/*
-		 * Check for merge if we've got an extent to the left,
-		 * otherwise make sure there's enough room at the start
-		 * of the file for the shift.
-		 */
-		if (!*current_ext) {
-			if (got->br_startoff < offset_shift_fsb)
-				return -EINVAL;
-			goto update_current_ext;
-		}
-
-		/*
-		 * grab the left extent and check for a large enough hole.
-		 */
-		xfs_iext_get_extent(ifp, *current_ext - 1, &adj_irec);
-		if (startoff < adj_irec.br_startoff + adj_irec.br_blockcount)
-			return -EINVAL;
-
-		/* check whether to merge the extent or shift it down */
-		if (xfs_bmse_can_merge(&adj_irec, got, offset_shift_fsb)) {
-			return xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
-					      *current_ext, got, &adj_irec,
-					      cur, logflags, dfops);
-		}
-	} else {
-		startoff = got->br_startoff + offset_shift_fsb;
-		/* nothing to move if this is the last extent */
-		if (*current_ext >= (total_extents - 1))
-			goto update_current_ext;
-
-		/*
-		 * If this is not the last extent in the file, make sure there
-		 * is enough room between current extent and next extent for
-		 * accommodating the shift.
-		 */
-		xfs_iext_get_extent(ifp, *current_ext + 1, &adj_irec);
-		if (startoff + got->br_blockcount > adj_irec.br_startoff)
-			return -EINVAL;
-
-		/*
-		 * Unlike a left shift (which involves a hole punch),
-		 * a right shift does not modify extent neighbors
-		 * in any way. We should never find mergeable extents
-		 * in this scenario. Check anyways and warn if we
-		 * encounter two extents that could be one.
-		 */
-		if (xfs_bmse_can_merge(got, &adj_irec, offset_shift_fsb))
-			WARN_ON_ONCE(1);
-	}
-
-	/*
-	 * Increment the extent index for the next iteration, update the start
-	 * offset of the in-core extent and update the btree if applicable.
-	 */
-update_current_ext:
 	*logflags |= XFS_ILOG_CORE;
 
-	new = *got;
-	new.br_startoff = startoff;
+	got->br_startoff = startoff;
 
 	if (cur) {
-		error = xfs_bmbt_lookup_eq(cur, got->br_startoff,
-				got->br_startblock, got->br_blockcount, &i);
+		error = xfs_bmbt_lookup_eq(cur, &prev, &i);
 		if (error)
 			return error;
 		XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
 
-		error = xfs_bmbt_update(cur, new.br_startoff,
-				new.br_startblock, new.br_blockcount,
-				new.br_state);
+		error = xfs_bmbt_update(cur, got);
 		if (error)
 			return error;
 	} else {
 		*logflags |= XFS_ILOG_DEXT;
 	}
 
-	xfs_iext_update_extent(ifp, *current_ext, &new);
-
-	if (direction == SHIFT_LEFT)
-		(*current_ext)++;
-	else
-		(*current_ext)--;
+	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), icur,
+			got);
 
 	/* update reverse mapping */
-	error = xfs_rmap_unmap_extent(mp, dfops, ip, whichfork, got);
+	error = xfs_rmap_unmap_extent(mp, dfops, ip, whichfork, &prev);
 	if (error)
 		return error;
-	return xfs_rmap_map_extent(mp, dfops, ip, whichfork, &new);
+	return xfs_rmap_map_extent(mp, dfops, ip, whichfork, got);
 }
 
-/*
- * Shift extent records to the left/right to cover/create a hole.
- *
- * The maximum number of extents to be shifted in a single operation is
- * @num_exts. @stop_fsb specifies the file offset at which to stop shift and the
- * file offset where we've left off is returned in @next_fsb. @offset_shift_fsb
- * is the length by which each extent is shifted. If there is no hole to shift
- * the extents into, this will be considered invalid operation and we abort
- * immediately.
- */
 int
-xfs_bmap_shift_extents(
+xfs_bmap_collapse_extents(
 	struct xfs_trans	*tp,
 	struct xfs_inode	*ip,
 	xfs_fileoff_t		*next_fsb,
 	xfs_fileoff_t		offset_shift_fsb,
-	int			*done,
+	bool			*done,
 	xfs_fileoff_t		stop_fsb,
 	xfs_fsblock_t		*firstblock,
-	struct xfs_defer_ops	*dfops,
-	enum shift_direction	direction,
-	int			num_exts)
+	struct xfs_defer_ops	*dfops)
 {
-	struct xfs_btree_cur		*cur = NULL;
-	struct xfs_bmbt_irec            got;
-	struct xfs_mount		*mp = ip->i_mount;
-	struct xfs_ifork		*ifp;
-	xfs_extnum_t			nexts = 0;
-	xfs_extnum_t			current_ext;
-	xfs_extnum_t			total_extents;
-	xfs_extnum_t			stop_extent;
-	int				error = 0;
-	int				whichfork = XFS_DATA_FORK;
-	int				logflags = 0;
+	int			whichfork = XFS_DATA_FORK;
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	struct xfs_btree_cur	*cur = NULL;
+	struct xfs_bmbt_irec	got, prev;
+	struct xfs_iext_cursor	icur;
+	xfs_fileoff_t		new_startoff;
+	int			error = 0;
+	int			logflags = 0;
 
 	if (unlikely(XFS_TEST_ERROR(
 	    (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
 	     XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE),
 	     mp, XFS_ERRTAG_BMAPIFORMAT))) {
-		XFS_ERROR_REPORT("xfs_bmap_shift_extents",
-				 XFS_ERRLEVEL_LOW, mp);
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
 		return -EFSCORRUPTED;
 	}
 
 	if (XFS_FORCED_SHUTDOWN(mp))
 		return -EIO;
 
-	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
-	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
-	ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT);
+	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL));
 
-	ifp = XFS_IFORK_PTR(ip, whichfork);
 	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
-		/* Read in all the extents */
 		error = xfs_iread_extents(tp, ip, whichfork);
 		if (error)
 			return error;
···
 		cur->bc_private.b.flags = 0;
 	}
 
-	/*
-	 * There may be delalloc extents in the data fork before the range we
-	 * are collapsing out, so we cannot use the count of real extents here.
-	 * Instead we have to calculate it from the incore fork.
-	 */
-	total_extents = xfs_iext_count(ifp);
-	if (total_extents == 0) {
-		*done = 1;
+	if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &icur, &got)) {
+		*done = true;
+		goto del_cursor;
+	}
+	XFS_WANT_CORRUPTED_RETURN(mp, !isnullstartblock(got.br_startblock));
+
+	new_startoff = got.br_startoff - offset_shift_fsb;
+	if (xfs_iext_peek_prev_extent(ifp, &icur, &prev)) {
+		if (new_startoff < prev.br_startoff + prev.br_blockcount) {
+			error = -EINVAL;
+			goto del_cursor;
+		}
+
+		if (xfs_bmse_can_merge(&prev, &got, offset_shift_fsb)) {
+			error = xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
+					&icur, &got, &prev, cur, &logflags,
+					dfops);
+			if (error)
+				goto del_cursor;
+			goto done;
+		}
+	} else {
+		if (got.br_startoff < offset_shift_fsb) {
+			error = -EINVAL;
+			goto del_cursor;
+		}
+	}
+
+	error = xfs_bmap_shift_update_extent(ip, whichfork, &icur, &got, cur,
+			&logflags, dfops, new_startoff);
+	if (error)
+		goto del_cursor;
+
+done:
+	if (!xfs_iext_next_extent(ifp, &icur, &got)) {
+		*done = true;
 		goto del_cursor;
 	}
 
-	/*
-	 * In case of first right shift, we need to initialize next_fsb
-	 */
-	if (*next_fsb == NULLFSBLOCK) {
-		ASSERT(direction == SHIFT_RIGHT);
-
-		current_ext = total_extents - 1;
-		xfs_iext_get_extent(ifp, current_ext, &got);
-		if (stop_fsb > got.br_startoff) {
-			*done = 1;
-			goto del_cursor;
-		}
-		*next_fsb = got.br_startoff;
-	} else {
-		/*
-		 * Look up the extent index for the fsb where we start shifting. We can
-		 * henceforth iterate with current_ext as extent list changes are locked
-		 * out via ilock.
-		 *
-		 * If next_fsb lies in a hole beyond which there are no extents we are
-		 * done.
-		 */
-		if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &current_ext,
-				&got)) {
-			*done = 1;
-			goto del_cursor;
-		}
-	}
-
-	/* Lookup the extent index at which we have to stop */
-	if (direction == SHIFT_RIGHT) {
-		struct xfs_bmbt_irec s;
-
-		xfs_iext_lookup_extent(ip, ifp, stop_fsb, &stop_extent, &s);
-		/* Make stop_extent exclusive of shift range */
-		stop_extent--;
-		if (current_ext <= stop_extent) {
-			error = -EIO;
-			goto del_cursor;
-		}
-	} else {
-		stop_extent = total_extents;
-		if (current_ext >= stop_extent) {
-			error = -EIO;
-			goto del_cursor;
-		}
-	}
-
-	while (nexts++ < num_exts) {
-		error = xfs_bmse_shift_one(ip, whichfork, offset_shift_fsb,
-					   &current_ext, &got, cur, &logflags,
-					   direction, dfops);
-		if (error)
-			goto del_cursor;
-		/*
-		 * If there was an extent merge during the shift, the extent
-		 * count can change. Update the total and grade the next record.
-		 */
-		if (direction == SHIFT_LEFT) {
-			total_extents = xfs_iext_count(ifp);
-			stop_extent = total_extents;
-		}
-
-		if (current_ext == stop_extent) {
-			*done = 1;
-			*next_fsb = NULLFSBLOCK;
-			break;
-		}
-		xfs_iext_get_extent(ifp, current_ext, &got);
-	}
-
-	if (!*done)
-		*next_fsb = got.br_startoff;
-
+	*next_fsb = got.br_startoff;
 del_cursor:
 	if (cur)
 		xfs_btree_del_cursor(cur,
 			error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
-
 	if (logflags)
 		xfs_trans_log_inode(tp, ip, logflags);
+	return error;
+}
 
+int
+xfs_bmap_insert_extents(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	xfs_fileoff_t		*next_fsb,
+	xfs_fileoff_t		offset_shift_fsb,
+	bool			*done,
+	xfs_fileoff_t		stop_fsb,
+	xfs_fsblock_t		*firstblock,
+	struct xfs_defer_ops	*dfops)
+{
+	int			whichfork = XFS_DATA_FORK;
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	struct xfs_btree_cur	*cur = NULL;
+	struct xfs_bmbt_irec	got, next;
+	struct xfs_iext_cursor	icur;
+	xfs_fileoff_t		new_startoff;
+	int			error = 0;
+	int			logflags = 0;
+
+	if (unlikely(XFS_TEST_ERROR(
+	    (XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	     XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE),
+	     mp, XFS_ERRTAG_BMAPIFORMAT))) {
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
+		return -EFSCORRUPTED;
+	}
+
+	if (XFS_FORCED_SHUTDOWN(mp))
+		return -EIO;
+
+	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL));
+
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		error = xfs_iread_extents(tp, ip, whichfork);
+		if (error)
+			return error;
+	}
+
+	if (ifp->if_flags & XFS_IFBROOT) {
+		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
+		cur->bc_private.b.firstblock = *firstblock;
+		cur->bc_private.b.dfops = dfops;
+		cur->bc_private.b.flags = 0;
+	}
+
+	if (*next_fsb == NULLFSBLOCK) {
+		xfs_iext_last(ifp, &icur);
+		if (!xfs_iext_get_extent(ifp, &icur, &got) ||
+		    stop_fsb > got.br_startoff) {
+			*done = true;
+			goto del_cursor;
+		}
+	} else {
+		if (!xfs_iext_lookup_extent(ip, ifp, *next_fsb, &icur, &got)) {
+			*done = true;
+			goto del_cursor;
+		}
+	}
+	XFS_WANT_CORRUPTED_RETURN(mp, !isnullstartblock(got.br_startblock));
+
+	if (stop_fsb >= got.br_startoff + got.br_blockcount) {
+		error = -EIO;
+		goto del_cursor;
+	}
+
+	new_startoff = got.br_startoff + offset_shift_fsb;
+	if (xfs_iext_peek_next_extent(ifp, &icur, &next)) {
+		if (new_startoff + got.br_blockcount > next.br_startoff) {
+			error = -EINVAL;
+			goto del_cursor;
+		}
+
+		/*
+		 * Unlike a left shift (which involves a hole punch), a right
+		 * shift does not modify extent neighbors in any way.  We should
+		 * never find mergeable extents in this scenario.  Check anyways
+		 * and warn if we encounter two extents that could be one.
+		 */
+		if (xfs_bmse_can_merge(&got, &next, offset_shift_fsb))
+			WARN_ON_ONCE(1);
+	}
+
+	error = xfs_bmap_shift_update_extent(ip, whichfork, &icur, &got, cur,
+			&logflags, dfops, new_startoff);
+	if (error)
+		goto del_cursor;
+
+	if (!xfs_iext_prev_extent(ifp, &icur, &got) ||
+	    stop_fsb >= got.br_startoff + got.br_blockcount) {
+		*done = true;
+		goto del_cursor;
+	}
+
+	*next_fsb = got.br_startoff;
+del_cursor:
+	if (cur)
+		xfs_btree_del_cursor(cur,
+			error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR);
+	if (logflags)
+		xfs_trans_log_inode(tp, ip, logflags);
 	return error;
 }
 
 /*
- * Splits an extent into two extents at split_fsb block such that it is
- * the first block of the current_ext. @current_ext is a target extent
- * to be split. @split_fsb is a block where the extents is split.
- * If split_fsb lies in a hole or the first block of extents, just return 0.
+ * Splits an extent into two extents at split_fsb block such that it is the
+ * first block of the current_ext. @ext is a target extent to be split.
+ * @split_fsb is a block where the extents is split.  If split_fsb lies in a
+ * hole or the first block of extents, just return 0.
  */
 STATIC int
 xfs_bmap_split_extent_at(
···
 	struct xfs_mount		*mp = ip->i_mount;
 	struct xfs_ifork		*ifp;
 	xfs_fsblock_t			gotblkcnt; /* new block count for got */
-	xfs_extnum_t			current_ext;
+	struct xfs_iext_cursor		icur;
 	int				error = 0;
 	int				logflags = 0;
 	int				i = 0;
···
 	/*
 	 * If there are not extents, or split_fsb lies in a hole we are done.
 	 */
-	if (!xfs_iext_lookup_extent(ip, ifp, split_fsb, &current_ext, &got) ||
+	if (!xfs_iext_lookup_extent(ip, ifp, split_fsb, &icur, &got) ||
 	    got.br_startoff >= split_fsb)
 		return 0;
 
···
 		cur->bc_private.b.firstblock = *firstfsb;
 		cur->bc_private.b.dfops = dfops;
 		cur->bc_private.b.flags = 0;
-		error = xfs_bmbt_lookup_eq(cur, got.br_startoff,
-				got.br_startblock,
-				got.br_blockcount,
-				&i);
+		error = xfs_bmbt_lookup_eq(cur, &got, &i);
 		if (error)
 			goto del_cursor;
 		XFS_WANT_CORRUPTED_GOTO(mp, i == 1, del_cursor);
 	}
 
 	got.br_blockcount = gotblkcnt;
-	xfs_iext_update_extent(ifp, current_ext, &got);
+	xfs_iext_update_extent(ip, xfs_bmap_fork_to_state(whichfork), &icur,
+			&got);
 
 	logflags = XFS_ILOG_CORE;
 	if (cur) {
-		error = xfs_bmbt_update(cur, got.br_startoff,
-				got.br_startblock,
-				got.br_blockcount,
-				got.br_state);
+		error = xfs_bmbt_update(cur, &got);
 		if (error)
 			goto del_cursor;
 	} else
 		logflags |= XFS_ILOG_DEXT;
 
 	/* Add new extent */
-	current_ext++;
-	xfs_iext_insert(ip, current_ext, 1, &new, 0);
+	xfs_iext_next(ifp, &icur);
+	xfs_iext_insert(ip, &icur, &new, 0);
 	XFS_IFORK_NEXT_SET(ip, whichfork,
 			   XFS_IFORK_NEXTENTS(ip, whichfork) + 1);
 
 	if (cur) {
-		error = xfs_bmbt_lookup_eq(cur, new.br_startoff,
-				new.br_startblock, new.br_blockcount,
-				&i);
+		error = xfs_bmbt_lookup_eq(cur, &new, &i);
 		if (error)
 			goto del_cursor;
 		XFS_WANT_CORRUPTED_GOTO(mp, i == 0, del_cursor);
-		cur->bc_rec.b.br_state = new.br_state;
-
 		error = xfs_btree_insert(cur, &i);
 		if (error)
 			goto del_cursor;

fs/xfs/libxfs/xfs_bmap.h

···
 	xfs_fsblock_t		blkno;	/* starting block of new extent */
 
 	struct xfs_btree_cur	*cur;	/* btree cursor */
-	xfs_extnum_t		idx;	/* current extent index */
+	struct xfs_iext_cursor	icur;	/* incore extent cursor */
 	int			nallocs;/* number of extents alloc'd */
 	int			logflags;/* flags for transaction logging */
 
···
 /* Only convert delalloc space, don't allocate entirely new extents */
 #define XFS_BMAPI_DELALLOC	0x400
 
+/* Only convert unwritten extents, don't allocate new blocks */
+#define XFS_BMAPI_CONVERT_ONLY	0x800
+
 #define XFS_BMAPI_FLAGS \
 	{ XFS_BMAPI_ENTIRE,	"ENTIRE" }, \
 	{ XFS_BMAPI_METADATA,	"METADATA" }, \
···
 	{ XFS_BMAPI_ZERO,	"ZERO" }, \
 	{ XFS_BMAPI_REMAP,	"REMAP" }, \
 	{ XFS_BMAPI_COWFORK,	"COWFORK" }, \
-	{ XFS_BMAPI_DELALLOC,	"DELALLOC" }
+	{ XFS_BMAPI_DELALLOC,	"DELALLOC" }, \
+	{ XFS_BMAPI_CONVERT_ONLY, "CONVERT_ONLY" }
 
 
 static inline int xfs_bmapi_aflag(int w)
···
 		!isnullstartblock(irec->br_startblock);
 }
 
-/*
- * This macro is used to determine how many extents will be shifted
- * in one write transaction. We could require two splits,
- * an extent move on the first and an extent merge on the second,
- * So it is proper that one extent is shifted inside write transaction
- * at a time.
- */
-#define XFS_BMAP_MAX_SHIFT_EXTENTS	1
-
-enum shift_direction {
-	SHIFT_LEFT = 0,
-	SHIFT_RIGHT,
-};
-
-#ifdef DEBUG
-void	xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
-		int whichfork, unsigned long caller_ip);
-#define	XFS_BMAP_TRACE_EXLIST(ip,c,w)	\
-	xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
-#else
-#define	XFS_BMAP_TRACE_EXLIST(ip,c,w)
-#endif
-
 void	xfs_trim_extent(struct xfs_bmbt_irec *irec, xfs_fileoff_t bno,
 		xfs_filblks_t len);
 void	xfs_trim_extent_eof(struct xfs_bmbt_irec *, struct xfs_inode *);
···
 int	xfs_bmap_last_offset(struct xfs_inode *ip, xfs_fileoff_t *unused,
 		int whichfork);
 int	xfs_bmap_one_block(struct xfs_inode *ip, int whichfork);
-int	xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
-		int whichfork);
 int	xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
 		xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 		int *nmap, int flags);
···
 		xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
 		struct xfs_defer_ops *dfops, int *done);
 int	xfs_bmap_del_extent_delay(struct xfs_inode *ip, int whichfork,
-		xfs_extnum_t *idx, struct xfs_bmbt_irec *got,
+		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *got,
 		struct xfs_bmbt_irec *del);
-void	xfs_bmap_del_extent_cow(struct xfs_inode *ip, xfs_extnum_t *idx,
-		struct xfs_bmbt_irec *got, struct xfs_bmbt_irec *del);
+void	xfs_bmap_del_extent_cow(struct xfs_inode *ip,
+		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *got,
+		struct xfs_bmbt_irec *del);
 uint	xfs_default_attroffset(struct xfs_inode *ip);
-int	xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
+int	xfs_bmap_collapse_extents(struct xfs_trans *tp, struct xfs_inode *ip,
 		xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
-		int *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
-		struct xfs_defer_ops *dfops, enum shift_direction direction,
-		int num_exts);
+		bool *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
+		struct xfs_defer_ops *dfops);
+int	xfs_bmap_insert_extents(struct xfs_trans *tp, struct xfs_inode *ip,
+		xfs_fileoff_t *next_fsb, xfs_fileoff_t offset_shift_fsb,
+		bool *done, xfs_fileoff_t stop_fsb, xfs_fsblock_t *firstblock,
+		struct xfs_defer_ops *dfops);
 int	xfs_bmap_split_extent(struct xfs_inode *ip, xfs_fileoff_t split_offset);
 int	xfs_bmapi_reserve_delalloc(struct xfs_inode *ip, int whichfork,
 		xfs_fileoff_t off, xfs_filblks_t len, xfs_filblks_t prealloc,
-		struct xfs_bmbt_irec *got, xfs_extnum_t *lastx, int eof);
+		struct xfs_bmbt_irec *got, struct xfs_iext_cursor *cur,
+		int eof);
 
 enum xfs_bmap_intent_type {
 	XFS_BMAP_MAP = 1,
···
 		struct xfs_inode *ip, struct xfs_bmbt_irec *imap);
 int	xfs_bmap_unmap_extent(struct xfs_mount *mp, struct xfs_defer_ops *dfops,
 		struct xfs_inode *ip, struct xfs_bmbt_irec *imap);
+
+static inline int xfs_bmap_fork_to_state(int whichfork)
+{
+	switch (whichfork) {
+	case XFS_ATTR_FORK:
+		return BMAP_ATTRFORK;
+	case XFS_COW_FORK:
+		return BMAP_COWFORK;
+	default:
+		return 0;
+	}
+}
 
 #endif	/* __XFS_BMAP_H__ */

fs/xfs/libxfs/xfs_bmap_btree.c

···
 #include "xfs_rmap.h"
 
 /*
- * Determine the extent state.
- */
-/* ARGSUSED */
-STATIC xfs_exntst_t
-xfs_extent_state(
-	xfs_filblks_t		blks,
-	int			extent_flag)
-{
-	if (extent_flag) {
-		ASSERT(blks != 0);	/* saved for DMIG */
-		return XFS_EXT_UNWRITTEN;
-	}
-	return XFS_EXT_NORM;
-}
-
-/*
  * Convert on-disk form of btree root to in-memory form.
  */
 void
···
 	memcpy(tpp, fpp, sizeof(*fpp) * dmxr);
 }
 
-/*
- * Convert a compressed bmap extent record to an uncompressed form.
- * This code must be in sync with the routines xfs_bmbt_get_startoff,
- * xfs_bmbt_get_startblock, xfs_bmbt_get_blockcount and xfs_bmbt_get_state.
- */
-STATIC void
-__xfs_bmbt_get_all(
-		uint64_t l0,
-		uint64_t l1,
-		xfs_bmbt_irec_t *s)
-{
-	int	ext_flag;
-	xfs_exntst_t st;
-
-	ext_flag = (int)(l0 >> (64 - BMBT_EXNTFLAG_BITLEN));
-	s->br_startoff = ((xfs_fileoff_t)l0 &
-			   xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
-	s->br_startblock = (((xfs_fsblock_t)l0 & xfs_mask64lo(9)) << 43) |
-			   (((xfs_fsblock_t)l1) >> 21);
-	s->br_blockcount = (xfs_filblks_t)(l1 & xfs_mask64lo(21));
-	/* This is xfs_extent_state() in-line */
-	if (ext_flag) {
-		ASSERT(s->br_blockcount != 0);	/* saved for DMIG */
-		st = XFS_EXT_UNWRITTEN;
-	} else
-		st = XFS_EXT_NORM;
-	s->br_state = st;
-}
-
 void
-xfs_bmbt_get_all(
-	xfs_bmbt_rec_host_t *r,
-	xfs_bmbt_irec_t *s)
+xfs_bmbt_disk_get_all(
+	struct xfs_bmbt_rec	*rec,
+	struct xfs_bmbt_irec	*irec)
 {
-	__xfs_bmbt_get_all(r->l0, r->l1, s);
-}
+	uint64_t		l0 = get_unaligned_be64(&rec->l0);
+	uint64_t		l1 = get_unaligned_be64(&rec->l1);
 
-/*
- * Extract the blockcount field from an in memory bmap extent record.
- */
-xfs_filblks_t
-xfs_bmbt_get_blockcount(
-	xfs_bmbt_rec_host_t	*r)
-{
-	return (xfs_filblks_t)(r->l1 & xfs_mask64lo(21));
-}
-
-/*
- * Extract the startblock field from an in memory bmap extent record.
- */
-xfs_fsblock_t
-xfs_bmbt_get_startblock(
-	xfs_bmbt_rec_host_t	*r)
-{
-	return (((xfs_fsblock_t)r->l0 & xfs_mask64lo(9)) << 43) |
-	       (((xfs_fsblock_t)r->l1) >> 21);
-}
-
-/*
- * Extract the startoff field from an in memory bmap extent record.
- */
-xfs_fileoff_t
-xfs_bmbt_get_startoff(
-	xfs_bmbt_rec_host_t	*r)
-{
-	return ((xfs_fileoff_t)r->l0 &
-		 xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
-}
-
-xfs_exntst_t
-xfs_bmbt_get_state(
-	xfs_bmbt_rec_host_t	*r)
-{
-	int	ext_flag;
-
-	ext_flag = (int)((r->l0) >> (64 - BMBT_EXNTFLAG_BITLEN));
-	return xfs_extent_state(xfs_bmbt_get_blockcount(r),
-				ext_flag);
+	irec->br_startoff = (l0 & xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
+	irec->br_startblock = ((l0 & xfs_mask64lo(9)) << 43) | (l1 >> 21);
+	irec->br_blockcount = l1 & xfs_mask64lo(21);
+	if (l0 >> (64 - BMBT_EXNTFLAG_BITLEN))
+		irec->br_state = XFS_EXT_UNWRITTEN;
+	else
+		irec->br_state = XFS_EXT_NORM;
 }
 
 /*
···
 		 xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN)) >> 9;
 }
 
-
-/*
- * Set all the fields in a bmap extent record from the arguments.
- */
-void
-xfs_bmbt_set_allf(
-	xfs_bmbt_rec_host_t	*r,
-	xfs_fileoff_t		startoff,
-	xfs_fsblock_t		startblock,
-	xfs_filblks_t		blockcount,
-	xfs_exntst_t		state)
-{
-	int		extent_flag = (state == XFS_EXT_NORM) ? 0 : 1;
-
-	ASSERT(state == XFS_EXT_NORM || state == XFS_EXT_UNWRITTEN);
-	ASSERT((startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)) == 0);
-	ASSERT((blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)) == 0);
-
-	ASSERT((startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)) == 0);
-
-	r->l0 = ((xfs_bmbt_rec_base_t)extent_flag << 63) |
-		((xfs_bmbt_rec_base_t)startoff << 9) |
-		((xfs_bmbt_rec_base_t)startblock >> 43);
-	r->l1 = ((xfs_bmbt_rec_base_t)startblock << 21) |
-		((xfs_bmbt_rec_base_t)blockcount &
-		(xfs_bmbt_rec_base_t)xfs_mask64lo(21));
-}
-
 /*
  * Set all the fields in a bmap extent record from the uncompressed form.
  */
 void
-xfs_bmbt_set_all(
-	xfs_bmbt_rec_host_t *r,
-	xfs_bmbt_irec_t	*s)
-{
-	xfs_bmbt_set_allf(r, s->br_startoff, s->br_startblock,
-			     s->br_blockcount, s->br_state);
-}
-
-
-/*
- * Set all the fields in a disk format bmap extent record from the arguments.
- */
-void
-xfs_bmbt_disk_set_allf(
-	xfs_bmbt_rec_t		*r,
-	xfs_fileoff_t		startoff,
-	xfs_fsblock_t		startblock,
-	xfs_filblks_t		blockcount,
-	xfs_exntst_t		state)
-{
-	int			extent_flag = (state == XFS_EXT_NORM) ? 0 : 1;
-
-	ASSERT(state == XFS_EXT_NORM || state == XFS_EXT_UNWRITTEN);
-	ASSERT((startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)) == 0);
-	ASSERT((blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)) == 0);
-	ASSERT((startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)) == 0);
-
-	r->l0 = cpu_to_be64(
-		((xfs_bmbt_rec_base_t)extent_flag << 63) |
-		 ((xfs_bmbt_rec_base_t)startoff << 9) |
-		 ((xfs_bmbt_rec_base_t)startblock >> 43));
-	r->l1 = cpu_to_be64(
-		((xfs_bmbt_rec_base_t)startblock << 21) |
-		 ((xfs_bmbt_rec_base_t)blockcount &
-		  (xfs_bmbt_rec_base_t)xfs_mask64lo(21)));
-}
-
-/*
- * Set all the fields in a bmap extent record from the uncompressed form.
- */
-STATIC void
 xfs_bmbt_disk_set_all(
-	xfs_bmbt_rec_t	*r,
-	xfs_bmbt_irec_t *s)
+	struct xfs_bmbt_rec	*r,
+	struct xfs_bmbt_irec	*s)
 {
-	xfs_bmbt_disk_set_allf(r, s->br_startoff, s->br_startblock,
-				  s->br_blockcount, s->br_state);
-}
+	int			extent_flag = (s->br_state != XFS_EXT_NORM);
 
-/*
- * Set the blockcount field in a bmap extent record.
- */
-void
-xfs_bmbt_set_blockcount(
-	xfs_bmbt_rec_host_t *r,
-	xfs_filblks_t	v)
-{
-	ASSERT((v & xfs_mask64hi(43)) == 0);
-	r->l1 = (r->l1 & (xfs_bmbt_rec_base_t)xfs_mask64hi(43)) |
-		  (xfs_bmbt_rec_base_t)(v & xfs_mask64lo(21));
-}
+	ASSERT(s->br_state == XFS_EXT_NORM || s->br_state == XFS_EXT_UNWRITTEN);
+	ASSERT(!(s->br_startoff & xfs_mask64hi(64-BMBT_STARTOFF_BITLEN)));
+	ASSERT(!(s->br_blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)));
+	ASSERT(!(s->br_startblock & xfs_mask64hi(64-BMBT_STARTBLOCK_BITLEN)));
 
-/*
- * Set the startblock field in a bmap extent record.
- */
-void
-xfs_bmbt_set_startblock(
-	xfs_bmbt_rec_host_t *r,
-	xfs_fsblock_t	v)
-{
-	ASSERT((v & xfs_mask64hi(12)) == 0);
-	r->l0 = (r->l0 & (xfs_bmbt_rec_base_t)xfs_mask64hi(55)) |
-		  (xfs_bmbt_rec_base_t)(v >> 43);
-	r->l1 = (r->l1 & (xfs_bmbt_rec_base_t)xfs_mask64lo(21)) |
-		  (xfs_bmbt_rec_base_t)(v << 21);
-}
-
-/*
- * Set the startoff field in a bmap extent record.
- */
-void
-xfs_bmbt_set_startoff(
-	xfs_bmbt_rec_host_t *r,
-	xfs_fileoff_t	v)
-{
-	ASSERT((v & xfs_mask64hi(9)) == 0);
-	r->l0 = (r->l0 & (xfs_bmbt_rec_base_t) xfs_mask64hi(1)) |
-		((xfs_bmbt_rec_base_t)v << 9) |
-		  (r->l0 & (xfs_bmbt_rec_base_t)xfs_mask64lo(9));
-}
-
-/*
- * Set the extent state field in a bmap extent record.
- */
-void
-xfs_bmbt_set_state(
-	xfs_bmbt_rec_host_t *r,
-	xfs_exntst_t	v)
-{
-	ASSERT(v == XFS_EXT_NORM || v == XFS_EXT_UNWRITTEN);
-	if (v == XFS_EXT_NORM)
-		r->l0 &= xfs_mask64lo(64 - BMBT_EXNTFLAG_BITLEN);
-	else
-		r->l0 |= xfs_mask64hi(BMBT_EXNTFLAG_BITLEN);
+	put_unaligned_be64(
+		((xfs_bmbt_rec_base_t)extent_flag << 63) |
+		 ((xfs_bmbt_rec_base_t)s->br_startoff << 9) |
+		 ((xfs_bmbt_rec_base_t)s->br_startblock >> 43), &r->l0);
+	put_unaligned_be64(
+		((xfs_bmbt_rec_base_t)s->br_startblock << 21) |
+		 ((xfs_bmbt_rec_base_t)s->br_blockcount &
+		  (xfs_bmbt_rec_base_t)xfs_mask64lo(21)), &r->l1);
 }
 
 /*

fs/xfs/libxfs/xfs_bmap_btree.h

···
  */
 extern void xfs_bmdr_to_bmbt(struct xfs_inode *, xfs_bmdr_block_t *, int,
 			struct xfs_btree_block *, int);
-extern void xfs_bmbt_get_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
-extern xfs_filblks_t xfs_bmbt_get_blockcount(xfs_bmbt_rec_host_t *r);
-extern xfs_fsblock_t xfs_bmbt_get_startblock(xfs_bmbt_rec_host_t *r);
-extern xfs_fileoff_t xfs_bmbt_get_startoff(xfs_bmbt_rec_host_t *r);
-extern xfs_exntst_t xfs_bmbt_get_state(xfs_bmbt_rec_host_t *r);
 
+void xfs_bmbt_disk_set_all(struct xfs_bmbt_rec *r, struct xfs_bmbt_irec *s);
 extern xfs_filblks_t xfs_bmbt_disk_get_blockcount(xfs_bmbt_rec_t *r);
 extern xfs_fileoff_t xfs_bmbt_disk_get_startoff(xfs_bmbt_rec_t *r);
-
-extern void xfs_bmbt_set_all(xfs_bmbt_rec_host_t *r, xfs_bmbt_irec_t *s);
-extern void xfs_bmbt_set_allf(xfs_bmbt_rec_host_t *r, xfs_fileoff_t o,
-			xfs_fsblock_t b, xfs_filblks_t c, xfs_exntst_t v);
-extern void xfs_bmbt_set_blockcount(xfs_bmbt_rec_host_t *r, xfs_filblks_t v);
-extern void xfs_bmbt_set_startblock(xfs_bmbt_rec_host_t *r, xfs_fsblock_t v);
-extern void xfs_bmbt_set_startoff(xfs_bmbt_rec_host_t *r, xfs_fileoff_t v);
-extern void xfs_bmbt_set_state(xfs_bmbt_rec_host_t *r, xfs_exntst_t v);
-
-extern void xfs_bmbt_disk_set_allf(xfs_bmbt_rec_t *r, xfs_fileoff_t o,
-			xfs_fsblock_t b, xfs_filblks_t c, xfs_exntst_t v);
+extern void xfs_bmbt_disk_get_all(xfs_bmbt_rec_t *r, xfs_bmbt_irec_t *s);
 
 extern void xfs_bmbt_to_bmdr(struct xfs_mount *, struct xfs_btree_block *, int,
 			xfs_bmdr_block_t *, int);
···
  * Check that the extent does not contain an invalid unwritten extent flag.
  */
 static inline bool xfs_bmbt_validate_extent(struct xfs_mount *mp, int whichfork,
-		struct xfs_bmbt_rec_host *ep)
+		struct xfs_bmbt_irec *irec)
 {
-	if (ep->l0 >> (64 - BMBT_EXNTFLAG_BITLEN) == 0)
+	if (irec->br_state == XFS_EXT_NORM)
 		return true;
 	if (whichfork == XFS_DATA_FORK &&
 	    xfs_sb_version_hasextflgbit(&mp->m_sb))

fs/xfs/libxfs/xfs_btree.c

···
 #include "xfs_inode_item.h"
 #include "xfs_buf_item.h"
 #include "xfs_btree.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
 #include "xfs_cksum.h"
···
 	return magic;
 }
 
-STATIC int				/* error (0 or EFSCORRUPTED) */
-xfs_btree_check_lblock(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	struct xfs_btree_block	*block,	/* btree long form block pointer */
-	int			level,	/* level of the btree block */
-	struct xfs_buf		*bp)	/* buffer for block, if any */
+/*
+ * Check a long btree block header.  Return the address of the failing check,
+ * or NULL if everything is ok.
+ */
+xfs_failaddr_t
+__xfs_btree_check_lblock(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	int			level,
+	struct xfs_buf		*bp)
 {
-	int			lblock_ok = 1; /* block passes checks */
-	struct xfs_mount	*mp;	/* file system mount point */
+	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_btnum_t		btnum = cur->bc_btnum;
-	int			crc;
-
-	mp = cur->bc_mp;
-	crc = xfs_sb_version_hascrc(&mp->m_sb);
+	int			crc = xfs_sb_version_hascrc(&mp->m_sb);
 
 	if (crc) {
-		lblock_ok = lblock_ok &&
-			uuid_equal(&block->bb_u.l.bb_uuid,
-				   &mp->m_sb.sb_meta_uuid) &&
-			block->bb_u.l.bb_blkno == cpu_to_be64(
-				bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
+		if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
+			return __this_address;
+		if (block->bb_u.l.bb_blkno !=
+		    cpu_to_be64(bp ? bp->b_bn : XFS_BUF_DADDR_NULL))
+			return __this_address;
+		if (block->bb_u.l.bb_pad != cpu_to_be32(0))
+			return __this_address;
 	}
 
-	lblock_ok = lblock_ok &&
-		be32_to_cpu(block->bb_magic) == xfs_btree_magic(crc, btnum) &&
-		be16_to_cpu(block->bb_level) == level &&
-		be16_to_cpu(block->bb_numrecs) <=
-			cur->bc_ops->get_maxrecs(cur, level) &&
-		block->bb_u.l.bb_leftsib &&
-		(block->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK) ||
-		 XFS_FSB_SANITY_CHECK(mp,
-			be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
-		block->bb_u.l.bb_rightsib &&
-		(block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK) ||
-		 XFS_FSB_SANITY_CHECK(mp,
-			be64_to_cpu(block->bb_u.l.bb_rightsib)));
+	if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
+		return __this_address;
+	if (be16_to_cpu(block->bb_level) != level)
+		return __this_address;
+	if (be16_to_cpu(block->bb_numrecs) >
+	    cur->bc_ops->get_maxrecs(cur, level))
+		return __this_address;
+	if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
+	    !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_leftsib),
+			level + 1))
+		return __this_address;
+	if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
+	    !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_rightsib),
+			level + 1))
+		return __this_address;
 
-	if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
+	return NULL;
+}
+
+/* Check a long btree block header. */
+static int
+xfs_btree_check_lblock(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	int			level,
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = cur->bc_mp;
+	xfs_failaddr_t		fa;
+
+	fa = __xfs_btree_check_lblock(cur, block, level, bp);
+	if (unlikely(XFS_TEST_ERROR(fa != NULL, mp,
 			XFS_ERRTAG_BTREE_CHECK_LBLOCK))) {
 		if (bp)
 			trace_xfs_btree_corrupt(bp, _RET_IP_);
···
 	return 0;
 }
 
-STATIC int				/* error (0 or EFSCORRUPTED) */
-xfs_btree_check_sblock(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	struct xfs_btree_block	*block,	/* btree short form block pointer */
-	int			level,	/* level of the btree block */
-	struct xfs_buf		*bp)	/* buffer containing block */
+/*
+ * Check a short btree block header.  Return the address of the failing check,
+ * or NULL if everything is ok.
+ */
+xfs_failaddr_t
+__xfs_btree_check_sblock(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	int			level,
+	struct xfs_buf		*bp)
 {
-	struct xfs_mount	*mp;	/* file system mount point */
-	struct xfs_buf		*agbp;	/* buffer for ag. freespace struct */
-	struct xfs_agf		*agf;	/* ag. freespace structure */
-	xfs_agblock_t		agflen;	/* native ag. freespace length */
-	int			sblock_ok = 1; /* block passes checks */
+	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_btnum_t		btnum = cur->bc_btnum;
-	int			crc;
-
-	mp = cur->bc_mp;
-	crc = xfs_sb_version_hascrc(&mp->m_sb);
-	agbp = cur->bc_private.a.agbp;
-	agf = XFS_BUF_TO_AGF(agbp);
-	agflen = be32_to_cpu(agf->agf_length);
+	int			crc = xfs_sb_version_hascrc(&mp->m_sb);
 
 	if (crc) {
-		sblock_ok = sblock_ok &&
-			uuid_equal(&block->bb_u.s.bb_uuid,
-				   &mp->m_sb.sb_meta_uuid) &&
-			block->bb_u.s.bb_blkno == cpu_to_be64(
-				bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
+		if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
+			return __this_address;
+		if (block->bb_u.s.bb_blkno !=
+		    cpu_to_be64(bp ? bp->b_bn : XFS_BUF_DADDR_NULL))
+			return __this_address;
 	}
 
-	sblock_ok = sblock_ok &&
-		be32_to_cpu(block->bb_magic) == xfs_btree_magic(crc, btnum) &&
-		be16_to_cpu(block->bb_level) == level &&
-		be16_to_cpu(block->bb_numrecs) <=
-			cur->bc_ops->get_maxrecs(cur, level) &&
-		(block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
-		 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
-		block->bb_u.s.bb_leftsib &&
-		(block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
-		 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
-		block->bb_u.s.bb_rightsib;
+	if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
+		return __this_address;
+	if (be16_to_cpu(block->bb_level) != level)
+		return __this_address;
+	if (be16_to_cpu(block->bb_numrecs) >
+	    cur->bc_ops->get_maxrecs(cur, level))
+		return __this_address;
+	if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) &&
+	    !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_leftsib),
+			level + 1))
+		return __this_address;
+	if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) &&
+	    !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_rightsib),
+			level + 1))
+		return __this_address;
 
-	if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
+	return NULL;
+}
+
+/* Check a short btree block header. */
+STATIC int
+xfs_btree_check_sblock(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	int			level,
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = cur->bc_mp;
+	xfs_failaddr_t		fa;
+
+	fa = __xfs_btree_check_sblock(cur, block, level, bp);
+	if (unlikely(XFS_TEST_ERROR(fa != NULL, mp,
 			XFS_ERRTAG_BTREE_CHECK_SBLOCK))) {
 		if (bp)
 			trace_xfs_btree_corrupt(bp, _RET_IP_);
···
 		return xfs_btree_check_sblock(cur, block, level, bp);
 }
 
-/*
- * Check that (long) pointer is ok.
- */
-int					/* error (0 or EFSCORRUPTED) */
+/* Check that this long pointer is valid and points within the fs. */
+bool
 xfs_btree_check_lptr(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	xfs_fsblock_t		bno,	/* btree block disk address */
-	int			level)	/* btree block level */
+	struct xfs_btree_cur	*cur,
+	xfs_fsblock_t		fsbno,
+	int			level)
 {
-	XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
-		level > 0 &&
-		bno != NULLFSBLOCK &&
-		XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
-	return 0;
+	if (level <= 0)
+		return false;
+	return xfs_verify_fsbno(cur->bc_mp, fsbno);
+}
+
+/* Check that this short pointer is valid and points within the AG. */
+bool
+xfs_btree_check_sptr(
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		agbno,
+	int			level)
+{
+	if (level <= 0)
+		return false;
+	return xfs_verify_agbno(cur->bc_mp, cur->bc_private.a.agno, agbno);
 }
 
 #ifdef DEBUG
 /*
- * Check that (short) pointer is ok.
+ * Check that a given (indexed) btree pointer at a certain level of a
+ * btree is valid and doesn't point past where it should.
  */
-STATIC int				/* error (0 or EFSCORRUPTED) */
-xfs_btree_check_sptr(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	xfs_agblock_t		bno,	/* btree block disk address */
-	int			level)	/* btree block level */
-{
-	xfs_agblock_t		agblocks = cur->bc_mp->m_sb.sb_agblocks;
-
-	XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
-		level > 0 &&
-		bno != NULLAGBLOCK &&
-		bno != 0 &&
-		bno < agblocks);
-	return 0;
-}
-
-/*
- * Check that block ptr is ok.
- */
-STATIC int				/* error (0 or EFSCORRUPTED) */
+static int
 xfs_btree_check_ptr(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	union xfs_btree_ptr	*ptr,	/* btree block disk address */
-	int			index,	/* offset from ptr to check */
-	int			level)	/* btree block level */
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_ptr	*ptr,
+	int			index,
+	int			level)
 {
 	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
-		return xfs_btree_check_lptr(cur,
-				be64_to_cpu((&ptr->l)[index]), level);
+		XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
+				xfs_btree_check_lptr(cur,
+					be64_to_cpu((&ptr->l)[index]), level));
 	} else {
-		return xfs_btree_check_sptr(cur,
-				be32_to_cpu((&ptr->s)[index]), level);
+		XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
+				xfs_btree_check_sptr(cur,
+					be32_to_cpu((&ptr->s)[index]), level));
 	}
+
+	return 0;
 }
 #endif
 
···
 	}
 }
 
-STATIC int
+bool
 xfs_btree_ptr_is_null(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_ptr	*ptr)
···
 /*
  * Get/set/init sibling pointers
  */
-STATIC void
+void
 xfs_btree_get_sibling(
 	struct xfs_btree_cur	*cur,
 	struct xfs_btree_block	*block,
···
 }
 
 /* Find the high key storage area from a regular key. */
-STATIC union xfs_btree_key *
+union xfs_btree_key *
 xfs_btree_high_key_from_key(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_key	*key)
···
 }
 
 /* Derive the keys for any btree block. */
-STATIC void
+void
 xfs_btree_get_keys(
 	struct xfs_btree_cur	*cur,
 	struct xfs_btree_block	*block,
···
 	*blocks = 0;
 	return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
 			blocks);
+}
+
+/* Compare two btree pointers. */
+int64_t
+xfs_btree_diff_two_ptrs(
+	struct xfs_btree_cur		*cur,
+	const union xfs_btree_ptr	*a,
+	const union xfs_btree_ptr	*b)
+{
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
+		return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l);
+	return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s);
 }

fs/xfs/libxfs/xfs_btree.h

···
  */
 #define	XFS_BUF_TO_BLOCK(bp)	((struct xfs_btree_block *)((bp)->b_addr))
 
+/*
+ * Internal long and short btree block checks.  They return NULL if the
+ * block is ok or the address of the failed check otherwise.
+ */
+xfs_failaddr_t __xfs_btree_check_lblock(struct xfs_btree_cur *cur,
+		struct xfs_btree_block *block, int level, struct xfs_buf *bp);
+xfs_failaddr_t __xfs_btree_check_sblock(struct xfs_btree_cur *cur,
+		struct xfs_btree_block *block, int level, struct xfs_buf *bp);
 
 /*
  * Check that block header is ok.
···
 /*
  * Check that (long) pointer is ok.
  */
-int					/* error (0 or EFSCORRUPTED) */
+bool					/* error (0 or EFSCORRUPTED) */
 xfs_btree_check_lptr(
 	struct xfs_btree_cur	*cur,	/* btree cursor */
-	xfs_fsblock_t		ptr,	/* btree block disk address */
+	xfs_fsblock_t		fsbno,	/* btree block disk address */
+	int			level);	/* btree block level */
+
+/*
+ * Check that (short) pointer is ok.
+ */
+bool					/* error (0 or EFSCORRUPTED) */
+xfs_btree_check_sptr(
+	struct xfs_btree_cur	*cur,	/* btree cursor */
+	xfs_agblock_t		agbno,	/* btree block disk address */
 	int			level);	/* btree block level */
 
 /*
···
 		union xfs_btree_ptr *pp, struct xfs_btree_block **blkp);
 struct xfs_btree_block *xfs_btree_get_block(struct xfs_btree_cur *cur,
 		int level, struct xfs_buf **bpp);
+bool xfs_btree_ptr_is_null(struct xfs_btree_cur *cur, union xfs_btree_ptr *ptr);
+int64_t xfs_btree_diff_two_ptrs(struct xfs_btree_cur *cur,
+				const union xfs_btree_ptr *a,
+				const union xfs_btree_ptr *b);
+void xfs_btree_get_sibling(struct xfs_btree_cur *cur,
+			   struct xfs_btree_block *block,
+			   union xfs_btree_ptr *ptr, int lr);
+void xfs_btree_get_keys(struct xfs_btree_cur *cur,
+		struct xfs_btree_block *block, union xfs_btree_key *key);
+union xfs_btree_key *xfs_btree_high_key_from_key(struct xfs_btree_cur *cur,
+		union xfs_btree_key *key);
 
 #endif	/* __XFS_BTREE_H__ */

fs/xfs/libxfs/xfs_da_btree.c

···
 	int			max;
 	int			error;
 	int			retval;
+	unsigned int		expected_level = 0;
 	struct xfs_inode	*dp = state->args->dp;
 
 	args = state->args;
···
 	 * Descend thru the B-tree searching each level for the right
 	 * node to use, until the right hashval is found.
 	 */
-	blkno = (args->whichfork == XFS_DATA_FORK)? args->geo->leafblk : 0;
+	blkno = args->geo->leafblk;
 	for (blk = &state->path.blk[0], state->path.active = 1;
 			 state->path.active <= XFS_DA_NODE_MAXDEPTH;
 			 blk++, state->path.active++) {
···
 		node = blk->bp->b_addr;
 		dp->d_ops->node_hdr_from_disk(&nodehdr, node);
 		btree = dp->d_ops->node_tree_p(node);
+
+		/* Tree taller than we can handle; bail out! */
+		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
+			return -EFSCORRUPTED;
+
+		/* Check the level from the root. */
+		if (blkno == args->geo->leafblk)
+			expected_level = nodehdr.level - 1;
+		else if (expected_level != nodehdr.level)
+			return -EFSCORRUPTED;
+		else
+			expected_level--;
 
 		max = nodehdr.count;
 		blk->hashval = be32_to_cpu(btree[max - 1].hashval);
···
 			blk->index = probe;
 			blkno = be32_to_cpu(btree[probe].before);
 		}
+
+		/* We can't point back to the root. */
+		if (blkno == args->geo->leafblk)
+			return -EFSCORRUPTED;
 	}
+
+	if (expected_level != 0)
+		return -EFSCORRUPTED;
 
 	/*
 	 * A leaf block that ends in the hashval that we are interested in

fs/xfs/libxfs/xfs_dir2.c

···
 #include "xfs_bmap.h"
 #include "xfs_dir2.h"
 #include "xfs_dir2_priv.h"
+#include "xfs_ialloc.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
 
···
 /*
  * Convert inode mode to directory entry filetype
  */
-unsigned char xfs_mode_to_ftype(int mode)
+unsigned char
+xfs_mode_to_ftype(
+	int		mode)
 {
 	switch (mode & S_IFMT) {
 	case S_IFREG:
···
 	xfs_mount_t	*mp,
 	xfs_ino_t	ino)
 {
-	xfs_agblock_t	agblkno;
-	xfs_agino_t	agino;
-	xfs_agnumber_t	agno;
-	int		ino_ok;
-	int		ioff;
+	bool		ino_ok = xfs_verify_dir_ino(mp, ino);
 
-	agno = XFS_INO_TO_AGNO(mp, ino);
-	agblkno = XFS_INO_TO_AGBNO(mp, ino);
-	ioff = XFS_INO_TO_OFFSET(mp, ino);
-	agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
-	ino_ok =
-		agno < mp->m_sb.sb_agcount &&
-		agblkno < mp->m_sb.sb_agblocks &&
-		agblkno != 0 &&
-		ioff < (1 << mp->m_sb.sb_inopblog) &&
-		XFS_AGINO_TO_INO(mp, agno, agino) == ino;
 	if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE))) {
 		xfs_warn(mp, "Invalid inode number 0x%Lx",
 				(unsigned long long) ino);

fs/xfs/libxfs/xfs_dir2.h

···
 		  sizeof(struct xfs_dir2_leaf_tail));
 }
 
+/*
+ * The Linux API doesn't pass down the total size of the buffer
+ * we read into down to the filesystem.  With the filldir concept
+ * it's not needed for correct information, but the XFS dir2 leaf
+ * code wants an estimate of the buffer size to calculate it's
+ * readahead window and size the buffers used for mapping to
+ * physical blocks.
+ *
+ * Try to give it an estimate that's good enough, maybe at some
+ * point we can change the ->readdir prototype to include the
+ * buffer size.  For now we use the current glibc buffer size.
+ * musl libc hardcodes 2k and dietlibc uses PAGE_SIZE.
+ */
+#define XFS_READDIR_BUFSIZE	(32768)
+
+unsigned char xfs_dir3_get_dtype(struct xfs_mount *mp, uint8_t filetype);
+
 #endif	/* __XFS_DIR2_H__ */

fs/xfs/libxfs/xfs_errortag.h

···
+/*
+ * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
+ * Copyright (C) 2017 Oracle.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_ERRORTAG_H_
+#define __XFS_ERRORTAG_H_
+
+/*
+ * error injection tags - the labels can be anything you want
+ * but each tag should have its own unique number
+ */
+
+#define XFS_ERRTAG_NOERROR				0
+#define XFS_ERRTAG_IFLUSH_1				1
+#define XFS_ERRTAG_IFLUSH_2				2
+#define XFS_ERRTAG_IFLUSH_3				3
+#define XFS_ERRTAG_IFLUSH_4				4
+#define XFS_ERRTAG_IFLUSH_5				5
+#define XFS_ERRTAG_IFLUSH_6				6
+#define XFS_ERRTAG_DA_READ_BUF				7
+#define XFS_ERRTAG_BTREE_CHECK_LBLOCK			8
+#define XFS_ERRTAG_BTREE_CHECK_SBLOCK			9
+#define XFS_ERRTAG_ALLOC_READ_AGF			10
+#define XFS_ERRTAG_IALLOC_READ_AGI			11
+#define XFS_ERRTAG_ITOBP_INOTOBP			12
+#define XFS_ERRTAG_IUNLINK				13
+#define XFS_ERRTAG_IUNLINK_REMOVE			14
+#define XFS_ERRTAG_DIR_INO_VALIDATE			15
+#define XFS_ERRTAG_BULKSTAT_READ_CHUNK			16
+#define XFS_ERRTAG_IODONE_IOERR				17
+#define XFS_ERRTAG_STRATREAD_IOERR			18
+#define XFS_ERRTAG_STRATCMPL_IOERR			19
+#define XFS_ERRTAG_DIOWRITE_IOERR			20
+#define XFS_ERRTAG_BMAPIFORMAT				21
+#define XFS_ERRTAG_FREE_EXTENT				22
+#define XFS_ERRTAG_RMAP_FINISH_ONE			23
+#define XFS_ERRTAG_REFCOUNT_CONTINUE_UPDATE		24
+#define XFS_ERRTAG_REFCOUNT_FINISH_ONE			25
+#define XFS_ERRTAG_BMAP_FINISH_ONE			26
+#define XFS_ERRTAG_AG_RESV_CRITICAL			27
+/*
+ * DEBUG mode instrumentation to test and/or trigger delayed allocation
+ * block killing in the event of failed writes. When enabled, all
+ * buffered writes are silenty dropped and handled as if they failed.
+ * All delalloc blocks in the range of the write (including pre-existing
+ * delalloc blocks!) are tossed as part of the write failure error
+ * handling sequence.
+ */
+#define XFS_ERRTAG_DROP_WRITES				28
+#define XFS_ERRTAG_LOG_BAD_CRC				29
+#define XFS_ERRTAG_LOG_ITEM_PIN				30
+#define XFS_ERRTAG_BUF_LRU_REF				31
+#define XFS_ERRTAG_MAX					32
+
+/*
+ * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
+ */
+#define XFS_RANDOM_DEFAULT				100
+#define XFS_RANDOM_IFLUSH_1				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IFLUSH_2				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IFLUSH_3				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IFLUSH_4				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IFLUSH_5				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IFLUSH_6				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_DA_READ_BUF				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_BTREE_CHECK_LBLOCK			(XFS_RANDOM_DEFAULT/4)
+#define XFS_RANDOM_BTREE_CHECK_SBLOCK			XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_ALLOC_READ_AGF			XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IALLOC_READ_AGI			XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_ITOBP_INOTOBP			XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IUNLINK				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IUNLINK_REMOVE			XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_DIR_INO_VALIDATE			XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_BULKSTAT_READ_CHUNK			XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_IODONE_IOERR				(XFS_RANDOM_DEFAULT/10)
+#define XFS_RANDOM_STRATREAD_IOERR			(XFS_RANDOM_DEFAULT/10)
+#define XFS_RANDOM_STRATCMPL_IOERR			(XFS_RANDOM_DEFAULT/10)
+#define XFS_RANDOM_DIOWRITE_IOERR			(XFS_RANDOM_DEFAULT/10)
+#define XFS_RANDOM_BMAPIFORMAT				XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_FREE_EXTENT				1
+#define XFS_RANDOM_RMAP_FINISH_ONE			1
+#define XFS_RANDOM_REFCOUNT_CONTINUE_UPDATE		1
+#define XFS_RANDOM_REFCOUNT_FINISH_ONE			1
+#define XFS_RANDOM_BMAP_FINISH_ONE			1
+#define XFS_RANDOM_AG_RESV_CRITICAL			4
+#define XFS_RANDOM_DROP_WRITES				1
+#define XFS_RANDOM_LOG_BAD_CRC				1
+#define XFS_RANDOM_LOG_ITEM_PIN				1
+#define XFS_RANDOM_BUF_LRU_REF				2
+
+#endif /* __XFS_ERRORTAG_H_ */

fs/xfs/libxfs/xfs_format.h

···
 	return false;
 }
 
+static inline bool xfs_sb_version_hasrealtime(struct xfs_sb *sbp)
+{
+	return sbp->sb_rblocks > 0;
+}
+
 /*
  * Detect a mismatched features2 field.  Older kernels read/wrote
  * this into the wrong slot, so to be safe we keep them in sync.
···
 /*
  * V5 superblock specific feature checks
  */
-static inline int xfs_sb_version_hascrc(struct xfs_sb *sbp)
+static inline bool xfs_sb_version_hascrc(struct xfs_sb *sbp)
 {
 	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
 }
 
-static inline int xfs_sb_version_has_pquotino(struct xfs_sb *sbp)
+static inline bool xfs_sb_version_has_pquotino(struct xfs_sb *sbp)
 {
 	return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
 }
···
 		 (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE));
 }
 
-static inline int xfs_sb_version_hasfinobt(xfs_sb_t *sbp)
+static inline bool xfs_sb_version_hasfinobt(xfs_sb_t *sbp)
 {
 	return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) &&
 		(sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT);
···
 	XFS_DINODE_FMT_LOCAL,		/* bulk data */
 	XFS_DINODE_FMT_EXTENTS,		/* struct xfs_bmbt_rec */
 	XFS_DINODE_FMT_BTREE,		/* struct xfs_bmdr_block */
-	XFS_DINODE_FMT_UUID		/* uuid_t */
+	XFS_DINODE_FMT_UUID		/* added long ago, but never used */
 } xfs_dinode_fmt_t;
 
 /*
···
  * Dquot and dquot block format definitions
  */
 #define XFS_DQUOT_MAGIC		0x4451		/* 'DQ' */
-#define XFS_DQUOT_VERSION	(u_int8_t)0x01	/* latest version number */
+#define XFS_DQUOT_VERSION	(uint8_t)0x01	/* latest version number */
 
 /*
  * This is the main portion of the on-disk representation of quota
···
 typedef uint64_t	xfs_bmbt_rec_base_t;	/* use this for casts */
 typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;
 
-typedef struct xfs_bmbt_rec_host {
-	uint64_t		l0, l1;
-} xfs_bmbt_rec_host_t;
-
 /*
  * Values and macros for delayed-allocation startblock fields.
  */
···
 {
 	return (xfs_filblks_t)((x) & ~STARTBLOCKMASK);
 }
-
-/*
- * Possible extent states.
- */
-typedef enum {
-	XFS_EXT_NORM, XFS_EXT_UNWRITTEN,
-} xfs_exntst_t;
-
-/*
- * Incore version of above.
- */
-typedef struct xfs_bmbt_irec
-{
-	xfs_fileoff_t	br_startoff;	/* starting file offset */
-	xfs_fsblock_t	br_startblock;	/* starting block number */
-	xfs_filblks_t	br_blockcount;	/* number of blocks */
-	xfs_exntst_t	br_state;	/* extent state */
-} xfs_bmbt_irec_t;
 
 /*
  * Key structure for non-leaf levels of the tree.

fs/xfs/libxfs/xfs_fs.h

···
 #define XFS_FSOP_GOING_FLAGS_LOGFLUSH		0x1	/* flush log but not data */
 #define XFS_FSOP_GOING_FLAGS_NOLOGFLUSH		0x2	/* don't flush log nor data */
 
+/* metadata scrubbing */
+struct xfs_scrub_metadata {
+	__u32 sm_type;		/* What to check? */
+	__u32 sm_flags;		/* flags; see below. */
+	__u64 sm_ino;		/* inode number. */
+	__u32 sm_gen;		/* inode generation. */
+	__u32 sm_agno;		/* ag number. */
+	__u64 sm_reserved[5];	/* pad to 64 bytes */
+};
+
+/*
+ * Metadata types and flags for scrub operation.
+ */
+
+/* Scrub subcommands. */
+#define XFS_SCRUB_TYPE_PROBE	0	/* presence test ioctl */
+#define XFS_SCRUB_TYPE_SB	1	/* superblock */
+#define XFS_SCRUB_TYPE_AGF	2	/* AG free header */
+#define XFS_SCRUB_TYPE_AGFL	3	/* AG free list */
+#define XFS_SCRUB_TYPE_AGI	4	/* AG inode header */
+#define XFS_SCRUB_TYPE_BNOBT	5	/* freesp by block btree */
+#define XFS_SCRUB_TYPE_CNTBT	6	/* freesp by length btree */
+#define XFS_SCRUB_TYPE_INOBT	7	/* inode btree */
+#define XFS_SCRUB_TYPE_FINOBT	8	/* free inode btree */
+#define XFS_SCRUB_TYPE_RMAPBT	9	/* reverse mapping btree */
+#define XFS_SCRUB_TYPE_REFCNTBT	10	/* reference count btree */
+#define XFS_SCRUB_TYPE_INODE	11	/* inode record */
+#define XFS_SCRUB_TYPE_BMBTD	12	/* data fork block mapping */
+#define XFS_SCRUB_TYPE_BMBTA	13	/* attr fork block mapping */
+#define XFS_SCRUB_TYPE_BMBTC	14	/* CoW fork block mapping */
+#define XFS_SCRUB_TYPE_DIR	15	/* directory */
+#define XFS_SCRUB_TYPE_XATTR	16	/* extended attribute */
+#define XFS_SCRUB_TYPE_SYMLINK	17	/* symbolic link */
+#define XFS_SCRUB_TYPE_PARENT	18	/* parent pointers */
+#define XFS_SCRUB_TYPE_RTBITMAP	19	/* realtime bitmap */
+#define XFS_SCRUB_TYPE_RTSUM	20	/* realtime summary */
+#define XFS_SCRUB_TYPE_UQUOTA	21	/* user quotas */
+#define XFS_SCRUB_TYPE_GQUOTA	22	/* group quotas */
+#define XFS_SCRUB_TYPE_PQUOTA	23	/* project quotas */
+
+/* Number of scrub subcommands. */
+#define XFS_SCRUB_TYPE_NR	24
+
+/* i: Repair this metadata. */
+#define XFS_SCRUB_IFLAG_REPAIR		(1 << 0)
+
+/* o: Metadata object needs repair. */
+#define XFS_SCRUB_OFLAG_CORRUPT		(1 << 1)
+
+/*
+ * o: Metadata object could be optimized.  It's not corrupt, but
+ *    we could improve on it somehow.
+ */
+#define XFS_SCRUB_OFLAG_PREEN		(1 << 2)
+
+/* o: Cross-referencing failed. */
+#define XFS_SCRUB_OFLAG_XFAIL		(1 << 3)
+
+/* o: Metadata object disagrees with cross-referenced metadata. */
+#define XFS_SCRUB_OFLAG_XCORRUPT	(1 << 4)
+
+/* o: Scan was not complete. */
+#define XFS_SCRUB_OFLAG_INCOMPLETE	(1 << 5)
+
+/* o: Metadata object looked funny but isn't corrupt. */
+#define XFS_SCRUB_OFLAG_WARNING		(1 << 6)
+
+#define XFS_SCRUB_FLAGS_IN	(XFS_SCRUB_IFLAG_REPAIR)
+#define XFS_SCRUB_FLAGS_OUT	(XFS_SCRUB_OFLAG_CORRUPT | \
+				 XFS_SCRUB_OFLAG_PREEN | \
+				 XFS_SCRUB_OFLAG_XFAIL | \
+				 XFS_SCRUB_OFLAG_XCORRUPT | \
+				 XFS_SCRUB_OFLAG_INCOMPLETE | \
+				 XFS_SCRUB_OFLAG_WARNING)
+#define XFS_SCRUB_FLAGS_ALL	(XFS_SCRUB_FLAGS_IN | XFS_SCRUB_FLAGS_OUT)
+
 /*
  * ioctl limits
  */
···
 #define XFS_IOC_ZERO_RANGE	_IOW ('X', 57, struct xfs_flock64)
 #define XFS_IOC_FREE_EOFBLOCKS	_IOR ('X', 58, struct xfs_fs_eofblocks)
 /*	XFS_IOC_GETFSMAP ------ hoisted 59         */
+#define XFS_IOC_SCRUB_METADATA	_IOWR('X', 60, struct xfs_scrub_metadata)
 
 /*
  * ioctl commands that replace IRIX syssgi()'s

fs/xfs/libxfs/xfs_ialloc.c

···
 #include "xfs_ialloc_btree.h"
 #include "xfs_alloc.h"
 #include "xfs_rtalloc.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_bmap.h"
 #include "xfs_cksum.h"
···
 	if (bp)
 		xfs_trans_brelse(tp, bp);
 	return 0;
+}
+
+/* Calculate the first and last possible inode number in an AG. */
+void
+xfs_ialloc_agino_range(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno,
+	xfs_agino_t		*first,
+	xfs_agino_t		*last)
+{
+	xfs_agblock_t		bno;
+	xfs_agblock_t		eoag;
+
+	eoag = xfs_ag_block_count(mp, agno);
+
+	/*
+	 * Calculate the first inode, which will be in the first
+	 * cluster-aligned block after the AGFL.
+	 */
+	bno = round_up(XFS_AGFL_BLOCK(mp) + 1,
+			xfs_ialloc_cluster_alignment(mp));
+	*first = XFS_OFFBNO_TO_AGINO(mp, bno, 0);
+
+	/*
+	 * Calculate the last inode, which will be at the end of the
+	 * last (aligned) cluster that can be allocated in the AG.
+	 */
+	bno = round_down(eoag, xfs_ialloc_cluster_alignment(mp));
+	*last = XFS_OFFBNO_TO_AGINO(mp, bno, 0) - 1;
+}
+
+/*
+ * Verify that an AG inode number pointer neither points outside the AG
+ * nor points at static metadata.
+ */
+bool
+xfs_verify_agino(
+	struct xfs_mount	*mp,
+	xfs_agnumber_t		agno,
+	xfs_agino_t		agino)
+{
+	xfs_agino_t		first;
+	xfs_agino_t		last;
+
+	xfs_ialloc_agino_range(mp, agno, &first, &last);
+	return agino >= first && agino <= last;
+}
+
+/*
+ * Verify that an FS inode number pointer neither points outside the
+ * filesystem nor points at static AG metadata.
+ */
+bool
+xfs_verify_ino(
+	struct xfs_mount	*mp,
+	xfs_ino_t		ino)
+{
+	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, ino);
+	xfs_agino_t		agino = XFS_INO_TO_AGINO(mp, ino);
+
+	if (agno >= mp->m_sb.sb_agcount)
+		return false;
+	if (XFS_AGINO_TO_INO(mp, agno, agino) != ino)
+		return false;
+	return xfs_verify_agino(mp, agno, agino);
+}
+
+/* Is this an internal inode number? */
+bool
+xfs_internal_inum(
+	struct xfs_mount	*mp,
+	xfs_ino_t		ino)
+{
+	return ino == mp->m_sb.sb_rbmino || ino == mp->m_sb.sb_rsumino ||
+		(xfs_sb_version_hasquota(&mp->m_sb) &&
+		 xfs_is_quota_inode(&mp->m_sb, ino));
+}
+
+/*
+ * Verify that a directory entry's inode number doesn't point at an internal
+ * inode, empty space, or static AG metadata.
+ */
+bool
+xfs_verify_dir_ino(
+	struct xfs_mount	*mp,
+	xfs_ino_t		ino)
+{
+	if (xfs_internal_inum(mp, ino))
+		return false;
+	return xfs_verify_ino(mp, ino);
 }

fs/xfs/libxfs/xfs_ialloc.h

···
 		struct xfs_inobt_rec_incore *irec);
 
 int xfs_ialloc_cluster_alignment(struct xfs_mount *mp);
+void xfs_ialloc_agino_range(struct xfs_mount *mp, xfs_agnumber_t agno,
+		xfs_agino_t *first, xfs_agino_t *last);
+bool xfs_verify_agino(struct xfs_mount *mp, xfs_agnumber_t agno,
+		xfs_agino_t agino);
+bool xfs_verify_ino(struct xfs_mount *mp, xfs_ino_t ino);
+bool xfs_internal_inum(struct xfs_mount *mp, xfs_ino_t ino);
+bool xfs_verify_dir_ino(struct xfs_mount *mp, xfs_ino_t ino);
 
 #endif	/* __XFS_IALLOC_H__ */

fs/xfs/libxfs/xfs_iext_tree.c

···
+/*
+ * Copyright (c) 2017 Christoph Hellwig.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/cache.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include "xfs.h"
+#include "xfs_format.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_inode.h"
+#include "xfs_inode_fork.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_trace.h"
+
+/*
+ * In-core extent record layout:
+ *
+ * +-------+----------------------------+
+ * | 00:53 | all 54 bits of startoff    |
+ * | 54:63 | low 10 bits of startblock  |
+ * +-------+----------------------------+
+ * | 00:20 | all 21 bits of length      |
+ * |    21 | unwritten extent bit       |
+ * | 22:63 | high 42 bits of startblock |
+ * +-------+----------------------------+
+ */
+#define XFS_IEXT_STARTOFF_MASK		xfs_mask64lo(BMBT_STARTOFF_BITLEN)
+#define XFS_IEXT_LENGTH_MASK		xfs_mask64lo(BMBT_BLOCKCOUNT_BITLEN)
+#define XFS_IEXT_STARTBLOCK_MASK	xfs_mask64lo(BMBT_STARTBLOCK_BITLEN)
+
+struct xfs_iext_rec {
+	uint64_t			lo;
+	uint64_t			hi;
+};
+
+/*
+ * Given that the length can't be a zero, only an empty hi value indicates an
+ * unused record.
+ */
+static bool xfs_iext_rec_is_empty(struct xfs_iext_rec *rec)
+{
+	return rec->hi == 0;
+}
+
+static inline void xfs_iext_rec_clear(struct xfs_iext_rec *rec)
+{
+	rec->lo = 0;
+	rec->hi = 0;
+}
+
+static void
+xfs_iext_set(
+	struct xfs_iext_rec	*rec,
+	struct xfs_bmbt_irec	*irec)
+{
+	ASSERT((irec->br_startoff & ~XFS_IEXT_STARTOFF_MASK) == 0);
+	ASSERT((irec->br_blockcount & ~XFS_IEXT_LENGTH_MASK) == 0);
+	ASSERT((irec->br_startblock & ~XFS_IEXT_STARTBLOCK_MASK) == 0);
+
+	rec->lo = irec->br_startoff & XFS_IEXT_STARTOFF_MASK;
+	rec->hi = irec->br_blockcount & XFS_IEXT_LENGTH_MASK;
+
+	rec->lo |= (irec->br_startblock << 54);
+	rec->hi |= ((irec->br_startblock & ~xfs_mask64lo(10)) << (22 - 10));
+
+	if (irec->br_state == XFS_EXT_UNWRITTEN)
+		rec->hi |= (1 << 21);
+}
+
+static void
+xfs_iext_get(
+	struct xfs_bmbt_irec	*irec,
+	struct xfs_iext_rec	*rec)
+{
+	irec->br_startoff = rec->lo & XFS_IEXT_STARTOFF_MASK;
+	irec->br_blockcount = rec->hi & XFS_IEXT_LENGTH_MASK;
+
+	irec->br_startblock = rec->lo >> 54;
+	irec->br_startblock |= (rec->hi & xfs_mask64hi(42)) >> (22 - 10);
+
+	if (rec->hi & (1 << 21))
+		irec->br_state = XFS_EXT_UNWRITTEN;
+	else
+		irec->br_state = XFS_EXT_NORM;
+}
+
+enum {
+	NODE_SIZE	= 256,
+	KEYS_PER_NODE	= NODE_SIZE / (sizeof(uint64_t) + sizeof(void *)),
+	RECS_PER_LEAF	= (NODE_SIZE - (2 * sizeof(struct xfs_iext_leaf *))) /
+				sizeof(struct xfs_iext_rec),
+};
+
+/*
+ * In-core extent btree block layout:
+ *
+ * There are two types of blocks in the btree: leaf and inner (non-leaf) blocks.
+ *
+ * The leaf blocks are made up by %KEYS_PER_NODE extent records, which each
+ * contain the startoffset, blockcount, startblock and unwritten extent flag.
+ * See above for the exact format, followed by pointers to the previous and next
+ * leaf blocks (if there are any).
+ *
+ * The inner (non-leaf) blocks first contain KEYS_PER_NODE lookup keys, followed
+ * by an equal number of pointers to the btree blocks at the next lower level.
+ *
+ *		+-------+-------+-------+-------+-------+----------+----------+
+ * Leaf:	| rec 1 | rec 2 | rec 3 | rec 4 | rec N | prev-ptr | next-ptr |
+ *		+-------+-------+-------+-------+-------+----------+----------+
+ *
+ *		+-------+-------+-------+-------+-------+-------+------+-------+
+ * Inner:	| key 1 | key 2 | key 3 | key N | ptr 1 | ptr 2 | ptr3 | ptr N |
+ *		+-------+-------+-------+-------+-------+-------+------+-------+
+ */
+struct xfs_iext_node {
+	uint64_t		keys[KEYS_PER_NODE];
+#define XFS_IEXT_KEY_INVALID	(1ULL << 63)
+	void			*ptrs[KEYS_PER_NODE];
+};
+
+struct xfs_iext_leaf {
+	struct xfs_iext_rec	recs[RECS_PER_LEAF];
+	struct xfs_iext_leaf	*prev;
+	struct xfs_iext_leaf	*next;
+};
+
+inline xfs_extnum_t xfs_iext_count(struct xfs_ifork *ifp)
+{
+	return ifp->if_bytes / sizeof(struct xfs_iext_rec);
+}
+
+static inline int xfs_iext_max_recs(struct xfs_ifork *ifp)
+{
+	if (ifp->if_height == 1)
+		return xfs_iext_count(ifp);
+	return RECS_PER_LEAF;
+}
+
+static inline struct xfs_iext_rec *cur_rec(struct xfs_iext_cursor *cur)
+{
+	return &cur->leaf->recs[cur->pos];
+}
+
+static inline bool xfs_iext_valid(struct xfs_ifork *ifp,
+		struct xfs_iext_cursor *cur)
+{
+	if (!cur->leaf)
+		return false;
+	if (cur->pos < 0 || cur->pos >= xfs_iext_max_recs(ifp))
+		return false;
+	if (xfs_iext_rec_is_empty(cur_rec(cur)))
+		return false;
+	return true;
+}
+
+static void *
+xfs_iext_find_first_leaf(
+	struct xfs_ifork	*ifp)
+{
+	struct xfs_iext_node	*node = ifp->if_u1.if_root;
+	int			height;
+
+	if (!ifp->if_height)
+		return NULL;
+
+	for (height = ifp->if_height; height > 1; height--) {
+		node = node->ptrs[0];
+		ASSERT(node);
+	}
+
+	return node;
+}
+
+static void *
+xfs_iext_find_last_leaf(
+	struct xfs_ifork	*ifp)
+{
+	struct xfs_iext_node	*node = ifp->if_u1.if_root;
+	int			height, i;
+
+	if (!ifp->if_height)
+		return NULL;
+
+	for (height = ifp->if_height; height > 1; height--) {
+		for (i = 1; i < KEYS_PER_NODE; i++)
+			if (!node->ptrs[i])
+				break;
+		node = node->ptrs[i - 1];
+		ASSERT(node);
+	}
+
+	return node;
+}
+
+void
+xfs_iext_first(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_cursor	*cur)
+{
+	cur->pos = 0;
+	cur->leaf = xfs_iext_find_first_leaf(ifp);
+}
+
+void
+xfs_iext_last(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_cursor	*cur)
+{
+	int			i;
+
+	cur->leaf = xfs_iext_find_last_leaf(ifp);
+	if (!cur->leaf) {
+		cur->pos = 0;
+		return;
+	}
+
+	for (i = 1; i < xfs_iext_max_recs(ifp); i++) {
+		if (xfs_iext_rec_is_empty(&cur->leaf->recs[i]))
+			break;
+	}
+	cur->pos = i - 1;
+}
+
+void
+xfs_iext_next(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_cursor	*cur)
+{
+	if (!cur->leaf) {
+		ASSERT(cur->pos <= 0 || cur->pos >= RECS_PER_LEAF);
+		xfs_iext_first(ifp, cur);
+		return;
+	}
+
+	ASSERT(cur->pos >= 0);
+	ASSERT(cur->pos < xfs_iext_max_recs(ifp));
+
+	cur->pos++;
+	if (ifp->if_height > 1 && !xfs_iext_valid(ifp, cur) &&
+	    cur->leaf->next) {
+		cur->leaf = cur->leaf->next;
+		cur->pos = 0;
+	}
+}
+
+void
+xfs_iext_prev(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_cursor	*cur)
+{
+	if (!cur->leaf) {
+		ASSERT(cur->pos <= 0 || cur->pos >= RECS_PER_LEAF);
+		xfs_iext_last(ifp, cur);
+		return;
+	}
+
+	ASSERT(cur->pos >= 0);
+	ASSERT(cur->pos <= RECS_PER_LEAF);
+
+recurse:
+	do {
+		cur->pos--;
+		if (xfs_iext_valid(ifp, cur))
+			return;
+	} while (cur->pos > 0);
+
+	if (ifp->if_height > 1 && cur->leaf->prev) {
+		cur->leaf = cur->leaf->prev;
+		cur->pos = RECS_PER_LEAF;
+		goto recurse;
+	}
+}
+
+static inline int
+xfs_iext_key_cmp(
+	struct xfs_iext_node	*node,
+	int			n,
+	xfs_fileoff_t		offset)
+{
+	if (node->keys[n] > offset)
+		return 1;
+	if (node->keys[n] < offset)
+		return -1;
+	return 0;
+}
+
+static inline int
+xfs_iext_rec_cmp(
+	struct xfs_iext_rec	*rec,
+	xfs_fileoff_t		offset)
+{
+	uint64_t		rec_offset = rec->lo & XFS_IEXT_STARTOFF_MASK;
+	u32			rec_len = rec->hi & XFS_IEXT_LENGTH_MASK;
+
+	if (rec_offset > offset)
+		return 1;
+	if (rec_offset + rec_len <= offset)
+		return -1;
+	return 0;
+}
+
+static void *
+xfs_iext_find_level(
+	struct xfs_ifork	*ifp,
+	xfs_fileoff_t		offset,
+	int			level)
+{
+	struct xfs_iext_node	*node = ifp->if_u1.if_root;
+	int			height, i;
+
+	if (!ifp->if_height)
+		return NULL;
+
+	for (height = ifp->if_height; height > level; height--) {
+		for (i = 1; i < KEYS_PER_NODE; i++)
+			if (xfs_iext_key_cmp(node, i, offset) > 0)
+				break;
+
+		node = node->ptrs[i - 1];
+		if (!node)
+			break;
+	}
+
+	return node;
+}
+
+static int
+xfs_iext_node_pos(
+	struct xfs_iext_node	*node,
+	xfs_fileoff_t		offset)
+{
+	int			i;
+
+	for (i = 1; i < KEYS_PER_NODE; i++) {
+		if (xfs_iext_key_cmp(node, i, offset) > 0)
+			break;
+	}
+
+	return i - 1;
+}
+
+static int
+xfs_iext_node_insert_pos(
+	struct xfs_iext_node	*node,
+	xfs_fileoff_t		offset)
+{
+	int			i;
+
+	for (i = 0; i < KEYS_PER_NODE; i++) {
+		if (xfs_iext_key_cmp(node, i, offset) > 0)
+			return i;
+	}
+
+	return KEYS_PER_NODE;
+}
+
+static int
+xfs_iext_node_nr_entries(
+	struct xfs_iext_node	*node,
+	int			start)
+{
+	int			i;
+
+	for (i = start; i < KEYS_PER_NODE; i++) {
+		if (node->keys[i] == XFS_IEXT_KEY_INVALID)
+			break;
+	}
+
+	return i;
+}
+
+static int
+xfs_iext_leaf_nr_entries(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_leaf	*leaf,
+	int			start)
+{
+	int			i;
+
+	for (i = start; i < xfs_iext_max_recs(ifp); i++) {
+		if (xfs_iext_rec_is_empty(&leaf->recs[i]))
+			break;
+	}
+
+	return i;
+}
+
+static inline uint64_t
+xfs_iext_leaf_key(
+	struct xfs_iext_leaf	*leaf,
+	int			n)
+{
+	return leaf->recs[n].lo & XFS_IEXT_STARTOFF_MASK;
+}
+
+static void
+xfs_iext_grow(
+	struct xfs_ifork	*ifp)
+{
+	struct xfs_iext_node	*node = kmem_zalloc(NODE_SIZE, KM_NOFS);
+	int			i;
+
+	if (ifp->if_height == 1) {
+		struct xfs_iext_leaf *prev = ifp->if_u1.if_root;
+
+		node->keys[0] = xfs_iext_leaf_key(prev, 0);
+		node->ptrs[0] = prev;
+	} else  {
+		struct xfs_iext_node *prev = ifp->if_u1.if_root;
+
+		ASSERT(ifp->if_height > 1);
+
+		node->keys[0] = prev->keys[0];
+		node->ptrs[0] = prev;
+	}
+
+	for (i = 1; i < KEYS_PER_NODE; i++)
+		node->keys[i] = XFS_IEXT_KEY_INVALID;
+
+	ifp->if_u1.if_root = node;
+	ifp->if_height++;
+}
+
+static void
+xfs_iext_update_node(
+	struct xfs_ifork	*ifp,
+	xfs_fileoff_t		old_offset,
+	xfs_fileoff_t		new_offset,
+	int			level,
+	void			*ptr)
+{
+	struct xfs_iext_node	*node = ifp->if_u1.if_root;
+	int			height, i;
+
+	for (height = ifp->if_height; height > level; height--) {
+		for (i = 0; i < KEYS_PER_NODE; i++) {
+			if (i > 0 && xfs_iext_key_cmp(node, i, old_offset) > 0)
+				break;
+			if (node->keys[i] == old_offset)
+				node->keys[i] = new_offset;
+		}
+		node = node->ptrs[i - 1];
+		ASSERT(node);
+	}
+
+	ASSERT(node == ptr);
+}
+
+static struct xfs_iext_node *
+xfs_iext_split_node(
+	struct xfs_iext_node	**nodep,
+	int			*pos,
+	int			*nr_entries)
+{
+	struct xfs_iext_node	*node = *nodep;
+	struct xfs_iext_node	*new = kmem_zalloc(NODE_SIZE, KM_NOFS);
+	const int		nr_move = KEYS_PER_NODE / 2;
+	int			nr_keep = nr_move + (KEYS_PER_NODE & 1);
+	int			i = 0;
+
+	/* for sequential append operations just spill over into the new node */
+	if (*pos == KEYS_PER_NODE) {
+		*nodep = new;
+		*pos = 0;
+		*nr_entries = 0;
+		goto done;
+	}
+
+
+	for (i = 0; i < nr_move; i++) {
+		new->keys[i] = node->keys[nr_keep + i];
+		new->ptrs[i] = node->ptrs[nr_keep + i];
+
+		node->keys[nr_keep + i] = XFS_IEXT_KEY_INVALID;
+		node->ptrs[nr_keep + i] = NULL;
+	}
+
+	if (*pos >= nr_keep) {
+		*nodep = new;
+		*pos -= nr_keep;
+		*nr_entries = nr_move;
+	} else {
+		*nr_entries = nr_keep;
+	}
+done:
+	for (; i < KEYS_PER_NODE; i++)
+		new->keys[i] = XFS_IEXT_KEY_INVALID;
+	return new;
+}
+
+static void
+xfs_iext_insert_node(
+	struct xfs_ifork	*ifp,
+	uint64_t		offset,
+	void			*ptr,
+	int			level)
+{
+	struct xfs_iext_node	*node, *new;
+	int			i, pos, nr_entries;
+
+again:
+	if (ifp->if_height < level)
+		xfs_iext_grow(ifp);
+
+	new = NULL;
+	node = xfs_iext_find_level(ifp, offset, level);
+	pos = xfs_iext_node_insert_pos(node, offset);
+	nr_entries = xfs_iext_node_nr_entries(node, pos);
+
+	ASSERT(pos >= nr_entries || xfs_iext_key_cmp(node, pos, offset) != 0);
+	ASSERT(nr_entries <= KEYS_PER_NODE);
+
+	if (nr_entries == KEYS_PER_NODE)
+		new = xfs_iext_split_node(&node, &pos, &nr_entries);
+
+	/*
+	 * Update the pointers in higher levels if the first entry changes
+	 * in an existing node.
+	 */
+	if (node != new && pos == 0 && nr_entries > 0)
+		xfs_iext_update_node(ifp, node->keys[0], offset, level, node);
+
+	for (i = nr_entries; i > pos; i--) {
+		node->keys[i] = node->keys[i - 1];
+		node->ptrs[i] = node->ptrs[i - 1];
+	}
+	node->keys[pos] = offset;
+	node->ptrs[pos] = ptr;
+
+	if (new) {
+		offset = new->keys[0];
+		ptr = new;
+		level++;
+		goto again;
+	}
+}
+
+static struct xfs_iext_leaf *
+xfs_iext_split_leaf(
+	struct xfs_iext_cursor	*cur,
+	int			*nr_entries)
+{
+	struct xfs_iext_leaf	*leaf = cur->leaf;
+	struct xfs_iext_leaf	*new = kmem_zalloc(NODE_SIZE, KM_NOFS);
+	const int		nr_move = RECS_PER_LEAF / 2;
+	int			nr_keep = nr_move + (RECS_PER_LEAF & 1);
+	int			i;
+
+	/* for sequential append operations just spill over into the new node */
+	if (cur->pos == RECS_PER_LEAF) {
+		cur->leaf = new;
+		cur->pos = 0;
+		*nr_entries = 0;
+		goto done;
+	}
+
+	for (i = 0; i < nr_move; i++) {
+		new->recs[i] = leaf->recs[nr_keep + i];
+		xfs_iext_rec_clear(&leaf->recs[nr_keep + i]);
+	}
+
+	if (cur->pos >= nr_keep) {
+		cur->leaf = new;
+		cur->pos -= nr_keep;
+		*nr_entries = nr_move;
+	} else {
+		*nr_entries = nr_keep;
+	}
+done:
+	if (leaf->next)
+		leaf->next->prev = new;
+	new->next = leaf->next;
+	new->prev = leaf;
+	leaf->next = new;
+	return new;
+}
+
+static void
+xfs_iext_alloc_root(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_cursor	*cur)
+{
+	ASSERT(ifp->if_bytes == 0);
+
+	ifp->if_u1.if_root = kmem_zalloc(sizeof(struct xfs_iext_rec), KM_NOFS);
+	ifp->if_height = 1;
+
+	/* now that we have a node step into it */
+	cur->leaf = ifp->if_u1.if_root;
+	cur->pos = 0;
+}
+
+static void
+xfs_iext_realloc_root(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_cursor	*cur)
+{
+	size_t new_size = ifp->if_bytes + sizeof(struct xfs_iext_rec);
+	void *new;
+
+	/* account for the prev/next pointers */
+	if (new_size / sizeof(struct xfs_iext_rec) == RECS_PER_LEAF)
+		new_size = NODE_SIZE;
+
+	new = kmem_realloc(ifp->if_u1.if_root, new_size, KM_NOFS);
+	memset(new + ifp->if_bytes, 0, new_size - ifp->if_bytes);
+	ifp->if_u1.if_root = new;
+	cur->leaf = new;
+}
+
+void
+xfs_iext_insert(
+	struct xfs_inode	*ip,
+	struct xfs_iext_cursor	*cur,
+	struct xfs_bmbt_irec	*irec,
+	int			state)
+{
+	struct xfs_ifork	*ifp = xfs_iext_state_to_fork(ip, state);
+	xfs_fileoff_t		offset = irec->br_startoff;
+	struct xfs_iext_leaf	*new = NULL;
+	int			nr_entries, i;
+
+	trace_xfs_iext_insert(ip, cur, state, _RET_IP_);
+
+	if (ifp->if_height == 0)
+		xfs_iext_alloc_root(ifp, cur);
+	else if (ifp->if_height == 1)
+		xfs_iext_realloc_root(ifp, cur);
+
+	nr_entries = xfs_iext_leaf_nr_entries(ifp, cur->leaf, cur->pos);
+	ASSERT(nr_entries <= RECS_PER_LEAF);
+	ASSERT(cur->pos >= nr_entries ||
+	       xfs_iext_rec_cmp(cur_rec(cur), irec->br_startoff) != 0);
+
+	if (nr_entries == RECS_PER_LEAF)
+		new = xfs_iext_split_leaf(cur, &nr_entries);
+
+	/*
+	 * Update the pointers in higher levels if the first entry changes
+	 * in an existing node.
+	 */
+	if (cur->leaf != new && cur->pos == 0 && nr_entries > 0) {
+		xfs_iext_update_node(ifp, xfs_iext_leaf_key(cur->leaf, 0),
+				offset, 1, cur->leaf);
+	}
+
+	for (i = nr_entries; i > cur->pos; i--)
+		cur->leaf->recs[i] = cur->leaf->recs[i - 1];
+	xfs_iext_set(cur_rec(cur), irec);
+	ifp->if_bytes += sizeof(struct xfs_iext_rec);
+
+	if (new)
+		xfs_iext_insert_node(ifp, xfs_iext_leaf_key(new, 0), new, 2);
+}
+
+static struct xfs_iext_node *
+xfs_iext_rebalance_node(
+	struct xfs_iext_node	*parent,
+	int			*pos,
+	struct xfs_iext_node	*node,
+	int			nr_entries)
+{
+	/*
+	 * If the neighbouring nodes are completely full, or have different
+	 * parents, we might never be able to merge our node, and will only
+	 * delete it once the number of entries hits zero.
+	 */
+	if (nr_entries == 0)
+		return node;
+
+	if (*pos > 0) {
+		struct xfs_iext_node *prev = parent->ptrs[*pos - 1];
+		int nr_prev = xfs_iext_node_nr_entries(prev, 0), i;
+
+		if (nr_prev + nr_entries <= KEYS_PER_NODE) {
+			for (i = 0; i < nr_entries; i++) {
+				prev->keys[nr_prev + i] = node->keys[i];
+				prev->ptrs[nr_prev + i] = node->ptrs[i];
+			}
+			return node;
+		}
+	}
+
+	if (*pos + 1 < xfs_iext_node_nr_entries(parent, *pos)) {
+		struct xfs_iext_node *next = parent->ptrs[*pos + 1];
+		int nr_next = xfs_iext_node_nr_entries(next, 0), i;
+
+		if (nr_entries + nr_next <= KEYS_PER_NODE) {
+			/*
+			 * Merge the next node into this node so that we don't
+			 * have to do an additional update of the keys in the
+			 * higher levels.
+			 */
+			for (i = 0; i < nr_next; i++) {
+				node->keys[nr_entries + i] = next->keys[i];
+				node->ptrs[nr_entries + i] = next->ptrs[i];
+			}
+
+			++*pos;
+			return next;
+		}
+	}
+
+	return NULL;
+}
+
+static void
+xfs_iext_remove_node(
+	struct xfs_ifork	*ifp,
+	xfs_fileoff_t		offset,
+	void			*victim)
+{
+	struct xfs_iext_node	*node, *parent;
+	int			level = 2, pos, nr_entries, i;
+
+	ASSERT(level <= ifp->if_height);
+	node = xfs_iext_find_level(ifp, offset, level);
+	pos = xfs_iext_node_pos(node, offset);
+again:
+	ASSERT(node->ptrs[pos]);
+	ASSERT(node->ptrs[pos] == victim);
+	kmem_free(victim);
+
+	nr_entries = xfs_iext_node_nr_entries(node, pos) - 1;
+	offset = node->keys[0];
+	for (i = pos; i < nr_entries; i++) {
+		node->keys[i] = node->keys[i + 1];
+		node->ptrs[i] = node->ptrs[i + 1];
+	}
+	node->keys[nr_entries] = XFS_IEXT_KEY_INVALID;
+	node->ptrs[nr_entries] = NULL;
+
+	if (pos == 0 && nr_entries > 0) {
+		xfs_iext_update_node(ifp, offset, node->keys[0], level, node);
+		offset = node->keys[0];
+	}
+
+	if (nr_entries >= KEYS_PER_NODE / 2)
+		return;
+
+	if (level < ifp->if_height) {
+		/*
+		 * If we aren't at the root yet try to find a neighbour node to
+		 * merge with (or delete the node if it is empty), and then
+		 * recurse up to the next level.
+		 */
+		level++;
+		parent = xfs_iext_find_level(ifp, offset, level);
+		pos = xfs_iext_node_pos(parent, offset);
+
+		ASSERT(pos != KEYS_PER_NODE);
+		ASSERT(parent->ptrs[pos] == node);
+
+		node = xfs_iext_rebalance_node(parent, &pos, node, nr_entries);
+		if (node) {
+			victim = node;
+			node = parent;
+			goto again;
+		}
+	} else if (nr_entries == 1) {
+		/*
+		 * If we are at the root and only one entry is left we can just
+		 * free this node and update the root pointer.
+		 */
+		ASSERT(node == ifp->if_u1.if_root);
+		ifp->if_u1.if_root = node->ptrs[0];
+		ifp->if_height--;
+		kmem_free(node);
+	}
+}
+
+static void
+xfs_iext_rebalance_leaf(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_cursor	*cur,
+	struct xfs_iext_leaf	*leaf,
+	xfs_fileoff_t		offset,
+	int			nr_entries)
+{
+	/*
+	 * If the neighbouring nodes are completely full we might never be able
+	 * to merge our node, and will only delete it once the number of
+	 * entries hits zero.
+	 */
+	if (nr_entries == 0)
+		goto remove_node;
+
+	if (leaf->prev) {
+		int nr_prev = xfs_iext_leaf_nr_entries(ifp, leaf->prev, 0), i;
+
+		if (nr_prev + nr_entries <= RECS_PER_LEAF) {
+			for (i = 0; i < nr_entries; i++)
+				leaf->prev->recs[nr_prev + i] = leaf->recs[i];
+
+			if (cur->leaf == leaf) {
+				cur->leaf = leaf->prev;
+				cur->pos += nr_prev;
+			}
+			goto remove_node;
+		}
+	}
+
+	if (leaf->next) {
+		int nr_next = xfs_iext_leaf_nr_entries(ifp, leaf->next, 0), i;
+
+		if (nr_entries + nr_next <= RECS_PER_LEAF) {
+			/*
+			 * Merge the next node into this node so that we don't
+			 * have to do an additional update of the keys in the
+			 * higher levels.
+			 */
+			for (i = 0; i < nr_next; i++) {
+				leaf->recs[nr_entries + i] =
+					leaf->next->recs[i];
+			}
+
+			if (cur->leaf == leaf->next) {
+				cur->leaf = leaf;
+				cur->pos += nr_entries;
+			}
+
+			offset = xfs_iext_leaf_key(leaf->next, 0);
+			leaf = leaf->next;
+			goto remove_node;
+		}
+	}
+
+	return;
+remove_node:
+	if (leaf->prev)
+		leaf->prev->next = leaf->next;
+	if (leaf->next)
+		leaf->next->prev = leaf->prev;
+	xfs_iext_remove_node(ifp, offset, leaf);
+}
+
+static void
+xfs_iext_free_last_leaf(
+	struct xfs_ifork	*ifp)
+{
+	ifp->if_u1.if_root = NULL;
+	ifp->if_height--;
+	kmem_free(ifp->if_u1.if_root);
+}
+
+void
+xfs_iext_remove(
+	struct xfs_inode	*ip,
+	struct xfs_iext_cursor	*cur,
+	int			state)
+{
+	struct xfs_ifork	*ifp = xfs_iext_state_to_fork(ip, state);
+	struct xfs_iext_leaf	*leaf = cur->leaf;
+	xfs_fileoff_t		offset = xfs_iext_leaf_key(leaf, 0);
+	int			i, nr_entries;
+
+	trace_xfs_iext_remove(ip, cur, state, _RET_IP_);
+
+	ASSERT(ifp->if_height > 0);
+	ASSERT(ifp->if_u1.if_root != NULL);
+	ASSERT(xfs_iext_valid(ifp, cur));
+
+	nr_entries = xfs_iext_leaf_nr_entries(ifp, leaf, cur->pos) - 1;
+	for (i = cur->pos; i < nr_entries; i++)
+		leaf->recs[i] = leaf->recs[i + 1];
+	xfs_iext_rec_clear(&leaf->recs[nr_entries]);
+	ifp->if_bytes -= sizeof(struct xfs_iext_rec);
+
+	if (cur->pos == 0 && nr_entries > 0) {
+		xfs_iext_update_node(ifp, offset, xfs_iext_leaf_key(leaf, 0), 1,
+				leaf);
+		offset = xfs_iext_leaf_key(leaf, 0);
+	} else if (cur->pos == nr_entries) {
+		if (ifp->if_height > 1 && leaf->next)
+			cur->leaf = leaf->next;
+		else
+			cur->leaf = NULL;
+		cur->pos = 0;
+	}
+
+	if (nr_entries >= RECS_PER_LEAF / 2)
+		return;
+
+	if (ifp->if_height > 1)
+		xfs_iext_rebalance_leaf(ifp, cur, leaf, offset, nr_entries);
+	else if (nr_entries == 0)
+		xfs_iext_free_last_leaf(ifp);
+}
+
+/*
+ * Lookup the extent covering bno.
+ *
+ * If there is an extent covering bno return the extent index, and store the
+ * expanded extent structure in *gotp, and the extent cursor in *cur.
+ * If there is no extent covering bno, but there is an extent after it (e.g.
+ * it lies in a hole) return that extent in *gotp and its cursor in *cur
+ * instead.
+ * If bno is beyond the last extent return false, and return an invalid
+ * cursor value.
+ */
+bool
+xfs_iext_lookup_extent(
+	struct xfs_inode	*ip,
+	struct xfs_ifork	*ifp,
+	xfs_fileoff_t		offset,
+	struct xfs_iext_cursor	*cur,
+	struct xfs_bmbt_irec	*gotp)
+{
+	XFS_STATS_INC(ip->i_mount, xs_look_exlist);
+
+	cur->leaf = xfs_iext_find_level(ifp, offset, 1);
+	if (!cur->leaf) {
+		cur->pos = 0;
+		return false;
+	}
+
+	for (cur->pos = 0; cur->pos < xfs_iext_max_recs(ifp); cur->pos++) {
+		struct xfs_iext_rec *rec = cur_rec(cur);
+
+		if (xfs_iext_rec_is_empty(rec))
+			break;
+		if (xfs_iext_rec_cmp(rec, offset) >= 0)
+			goto found;
+	}
+
+	/* Try looking in the next node for an entry > offset */
+	if (ifp->if_height == 1 || !cur->leaf->next)
+		return false;
+	cur->leaf = cur->leaf->next;
+	cur->pos = 0;
+	if (!xfs_iext_valid(ifp, cur))
+		return false;
+found:
+	xfs_iext_get(gotp, cur_rec(cur));
+	return true;
+}
+
+/*
+ * Returns the last extent before end, and if this extent doesn't cover
+ * end, update end to the end of the extent.
+ */
+bool
+xfs_iext_lookup_extent_before(
+	struct xfs_inode	*ip,
+	struct xfs_ifork	*ifp,
+	xfs_fileoff_t		*end,
+	struct xfs_iext_cursor	*cur,
+	struct xfs_bmbt_irec	*gotp)
+{
+	/* could be optimized to not even look up the next on a match.. */
+	if (xfs_iext_lookup_extent(ip, ifp, *end - 1, cur, gotp) &&
+	    gotp->br_startoff <= *end - 1)
+		return true;
+	if (!xfs_iext_prev_extent(ifp, cur, gotp))
+		return false;
+	*end = gotp->br_startoff + gotp->br_blockcount;
+	return true;
+}
+
+void
+xfs_iext_update_extent(
+	struct xfs_inode	*ip,
+	int			state,
+	struct xfs_iext_cursor	*cur,
+	struct xfs_bmbt_irec	*new)
+{
+	struct xfs_ifork	*ifp = xfs_iext_state_to_fork(ip, state);
+
+	if (cur->pos == 0) {
+		struct xfs_bmbt_irec	old;
+
+		xfs_iext_get(&old, cur_rec(cur));
+		if (new->br_startoff != old.br_startoff) {
+			xfs_iext_update_node(ifp, old.br_startoff,
+					new->br_startoff, 1, cur->leaf);
+		}
+	}
+
+	trace_xfs_bmap_pre_update(ip, cur, state, _RET_IP_);
+	xfs_iext_set(cur_rec(cur), new);
+	trace_xfs_bmap_post_update(ip, cur, state, _RET_IP_);
+}
+
+/*
+ * Return true if the cursor points at an extent and return the extent structure
+ * in gotp.  Else return false.
+ */
+bool
+xfs_iext_get_extent(
+	struct xfs_ifork	*ifp,
+	struct xfs_iext_cursor	*cur,
+	struct xfs_bmbt_irec	*gotp)
+{
+	if (!xfs_iext_valid(ifp, cur))
+		return false;
+	xfs_iext_get(gotp, cur_rec(cur));
+	return true;
+}
+
+/*
+ * This is a recursive function, because of that we need to be extremely
+ * careful with stack usage.
+ */
+static void
+xfs_iext_destroy_node(
+	struct xfs_iext_node	*node,
+	int			level)
+{
+	int			i;
+
+	if (level > 1) {
+		for (i = 0; i < KEYS_PER_NODE; i++) {
+			if (node->keys[i] == XFS_IEXT_KEY_INVALID)
+				break;
+			xfs_iext_destroy_node(node->ptrs[i], level - 1);
+		}
+	}
+
+	kmem_free(node);
+}
+
+void
+xfs_iext_destroy(
+	struct xfs_ifork	*ifp)
+{
+	xfs_iext_destroy_node(ifp->if_u1.if_root, ifp->if_height);
+
+	ifp->if_bytes = 0;
+	ifp->if_height = 0;
+	ifp->if_u1.if_root = NULL;
+}

fs/xfs/libxfs/xfs_inode_buf.c

···
 #include "xfs_mount.h"
 #include "xfs_defer.h"
 #include "xfs_inode.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_cksum.h"
 #include "xfs_icache.h"

fs/xfs/libxfs/xfs_inode_fork.c

···
 STATIC int xfs_iformat_extents(xfs_inode_t *, xfs_dinode_t *, int);
 STATIC int xfs_iformat_btree(xfs_inode_t *, xfs_dinode_t *, int);
 
+static inline dev_t xfs_to_linux_dev_t(xfs_dev_t dev)
+{
+	return MKDEV(sysv_major(dev) & 0x1ff, sysv_minor(dev));
+}
+
 /*
- * Move inode type and inode format specific information from the
- * on-disk inode to the in-core inode.  For fifos, devs, and sockets
- * this means set if_rdev to the proper value.  For files, directories,
- * and symlinks this means to bring in the in-line data or extent
- * pointers.  For a file in B-tree format, only the root is immediately
- * brought in-core.  The rest will be in-lined in if_extents when it
- * is first referenced (see xfs_iread_extents()).
+ * Copy inode type and data and attr format specific information from the
+ * on-disk inode to the in-core inode and fork structures.  For fifos, devices,
+ * and sockets this means set i_rdev to the proper value.  For files,
+ * directories, and symlinks this means to bring in the in-line data or extent
+ * pointers as well as the attribute fork.  For a fork in B-tree format, only
+ * the root is immediately brought in-core.  The rest will be read in later when
+ * first referenced (see xfs_iread_extents()).
  */
 int
 xfs_iformat_fork(
-	xfs_inode_t		*ip,
-	xfs_dinode_t		*dip)
+	struct xfs_inode	*ip,
+	struct xfs_dinode	*dip)
 {
-	xfs_attr_shortform_t	*atp;
+	struct inode		*inode = VFS_I(ip);
+	struct xfs_attr_shortform *atp;
 	int			size;
 	int			error = 0;
 	xfs_fsize_t             di_size;
···
 		return -EFSCORRUPTED;
 	}
 
-	if (unlikely(xfs_is_reflink_inode(ip) &&
-	    (VFS_I(ip)->i_mode & S_IFMT) != S_IFREG)) {
+	if (unlikely(xfs_is_reflink_inode(ip) && !S_ISREG(inode->i_mode))) {
 		xfs_warn(ip->i_mount,
 			"corrupt dinode %llu, wrong file type for reflink.",
 			ip->i_ino);
···
 		return -EFSCORRUPTED;
 	}
 
-	switch (VFS_I(ip)->i_mode & S_IFMT) {
+	switch (inode->i_mode & S_IFMT) {
 	case S_IFIFO:
 	case S_IFCHR:
 	case S_IFBLK:
···
 			return -EFSCORRUPTED;
 		}
 		ip->i_d.di_size = 0;
-		ip->i_df.if_u2.if_rdev = xfs_dinode_get_rdev(dip);
+		inode->i_rdev = xfs_to_linux_dev_t(xfs_dinode_get_rdev(dip));
 		break;
 
 	case S_IFREG:
···
 		return error;
 
 	/* Check inline dir contents. */
-	if (S_ISDIR(VFS_I(ip)->i_mode) &&
-	    dip->di_format == XFS_DINODE_FMT_LOCAL) {
+	if (S_ISDIR(inode->i_mode) && dip->di_format == XFS_DINODE_FMT_LOCAL) {
 		error = xfs_dir2_sf_verify(ip);
 		if (error) {
 			xfs_idestroy_fork(ip, XFS_DATA_FORK);
···
 	if (zero_terminate)
 		mem_size++;
 
-	if (size == 0)
-		ifp->if_u1.if_data = NULL;
-	else if (mem_size <= sizeof(ifp->if_u2.if_inline_data))
-		ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
-	else {
+	if (size) {
 		real_size = roundup(mem_size, 4);
 		ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP | KM_NOFS);
-	}
-
-	if (size) {
 		memcpy(ifp->if_u1.if_data, data, size);
 		if (zero_terminate)
 			ifp->if_u1.if_data[size] = '\0';
+	} else {
+		ifp->if_u1.if_data = NULL;
 	}
 
 	ifp->if_bytes = size;
···
 
 /*
  * The file is in-lined in the on-disk inode.
- * If it fits into if_inline_data, then copy
- * it there, otherwise allocate a buffer for it
- * and copy the data there.  Either way, set
- * if_data to point at the data.
- * If we allocate a buffer for the data, make
- * sure that its size is a multiple of 4 and
- * record the real size in i_real_bytes.
  */
 STATIC int
 xfs_iformat_local(
···
 
 /*
  * The file consists of a set of extents all of which fit into the on-disk
- * inode.  If there are few enough extents to fit into the if_inline_ext, then
- * copy them there.  Otherwise allocate a buffer for them and copy them into it.
- * Either way, set if_extents to point at the extents.
+ * inode.
  */
 STATIC int
 xfs_iformat_extents(
···
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	int			state = xfs_bmap_fork_to_state(whichfork);
 	int			nex = XFS_DFORK_NEXTENTS(dip, whichfork);
 	int			size = nex * sizeof(xfs_bmbt_rec_t);
+	struct xfs_iext_cursor	icur;
 	struct xfs_bmbt_rec	*dp;
+	struct xfs_bmbt_irec	new;
 	int			i;
 
 	/*
···
 	}
 
 	ifp->if_real_bytes = 0;
-	if (nex == 0)
-		ifp->if_u1.if_extents = NULL;
-	else if (nex <= XFS_INLINE_EXTS)
-		ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
-	else
-		xfs_iext_add(ifp, 0, nex);
-
-	ifp->if_bytes = size;
+	ifp->if_bytes = 0;
+	ifp->if_u1.if_root = NULL;
+	ifp->if_height = 0;
 	if (size) {
 		dp = (xfs_bmbt_rec_t *) XFS_DFORK_PTR(dip, whichfork);
+
+		xfs_iext_first(ifp, &icur);
 		for (i = 0; i < nex; i++, dp++) {
-			xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, i);
-			ep->l0 = get_unaligned_be64(&dp->l0);
-			ep->l1 = get_unaligned_be64(&dp->l1);
-			if (!xfs_bmbt_validate_extent(mp, whichfork, ep)) {
+			xfs_bmbt_disk_get_all(dp, &new);
+			if (!xfs_bmbt_validate_extent(mp, whichfork, &new)) {
 				XFS_ERROR_REPORT("xfs_iformat_extents(2)",
 						 XFS_ERRLEVEL_LOW, mp);
 				return -EFSCORRUPTED;
 			}
+
+			xfs_iext_insert(ip, &icur, &new, state);
+			trace_xfs_read_extent(ip, &icur, state, _THIS_IP_);
+			xfs_iext_next(ifp, &icur);
 		}
-		XFS_BMAP_TRACE_EXLIST(ip, nex, whichfork);
 	}
 	ifp->if_flags |= XFS_IFEXTENTS;
 	return 0;
···
 	ifp->if_flags &= ~XFS_IFEXTENTS;
 	ifp->if_flags |= XFS_IFBROOT;
 
+	ifp->if_real_bytes = 0;
+	ifp->if_bytes = 0;
+	ifp->if_u1.if_root = NULL;
+	ifp->if_height = 0;
 	return 0;
 }
 
-/*
- * Read in extents from a btree-format inode.
- * Allocate and fill in if_extents.  Real work is done in xfs_bmap.c.
- */
-int
-xfs_iread_extents(
-	xfs_trans_t	*tp,
-	xfs_inode_t	*ip,
-	int		whichfork)
-{
-	int		error;
-	xfs_ifork_t	*ifp;
-	xfs_extnum_t	nextents;
-
-	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
-
-	if (unlikely(XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)) {
-		XFS_ERROR_REPORT("xfs_iread_extents", XFS_ERRLEVEL_LOW,
-				 ip->i_mount);
-		return -EFSCORRUPTED;
-	}
-	nextents = XFS_IFORK_NEXTENTS(ip, whichfork);
-	ifp = XFS_IFORK_PTR(ip, whichfork);
-
-	/*
-	 * We know that the size is valid (it's checked in iformat_btree)
-	 */
-	ifp->if_bytes = ifp->if_real_bytes = 0;
-	xfs_iext_add(ifp, 0, nextents);
-	error = xfs_bmap_read_extents(tp, ip, whichfork);
-	if (error) {
-		xfs_iext_destroy(ifp);
-		return error;
-	}
-	ifp->if_flags |= XFS_IFEXTENTS;
-	return 0;
-}
 /*
  * Reallocate the space for if_broot based on the number of records
  * being added or deleted as indicated in rec_diff.  Move the records
···
 	ASSERT(new_size >= 0);
 
 	if (new_size == 0) {
-		if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
-			kmem_free(ifp->if_u1.if_data);
-		}
+		kmem_free(ifp->if_u1.if_data);
 		ifp->if_u1.if_data = NULL;
-		real_size = 0;
-	} else if (new_size <= sizeof(ifp->if_u2.if_inline_data)) {
-		/*
-		 * If the valid extents/data can fit in if_inline_ext/data,
-		 * copy them from the malloc'd vector and free it.
-		 */
-		if (ifp->if_u1.if_data == NULL) {
-			ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
-		} else if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
-			ASSERT(ifp->if_real_bytes != 0);
-			memcpy(ifp->if_u2.if_inline_data, ifp->if_u1.if_data,
-			      new_size);
-			kmem_free(ifp->if_u1.if_data);
-			ifp->if_u1.if_data = ifp->if_u2.if_inline_data;
-		}
 		real_size = 0;
 	} else {
 		/*
···
 			ASSERT(ifp->if_real_bytes == 0);
 			ifp->if_u1.if_data = kmem_alloc(real_size,
 							KM_SLEEP | KM_NOFS);
-		} else if (ifp->if_u1.if_data != ifp->if_u2.if_inline_data) {
+		} else {
 			/*
 			 * Only do the realloc if the underlying size
 			 * is really changing.
···
 							real_size,
 							KM_SLEEP | KM_NOFS);
 			}
-		} else {
-			ASSERT(ifp->if_real_bytes == 0);
-			ifp->if_u1.if_data = kmem_alloc(real_size,
-							KM_SLEEP | KM_NOFS);
-			memcpy(ifp->if_u1.if_data, ifp->if_u2.if_inline_data,
-				ifp->if_bytes);
 		}
 	}
 	ifp->if_real_bytes = real_size;
···
 	 * so check and free it up if we do.
 	 */
 	if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
-		if ((ifp->if_u1.if_data != ifp->if_u2.if_inline_data) &&
-		    (ifp->if_u1.if_data != NULL)) {
+		if (ifp->if_u1.if_data != NULL) {
 			ASSERT(ifp->if_real_bytes != 0);
 			kmem_free(ifp->if_u1.if_data);
 			ifp->if_u1.if_data = NULL;
 			ifp->if_real_bytes = 0;
 		}
-	} else if ((ifp->if_flags & XFS_IFEXTENTS) &&
-		   ((ifp->if_flags & XFS_IFEXTIREC) ||
-		    ((ifp->if_u1.if_extents != NULL) &&
-		     (ifp->if_u1.if_extents != ifp->if_u2.if_inline_ext)))) {
-		ASSERT(ifp->if_real_bytes != 0);
+	} else if ((ifp->if_flags & XFS_IFEXTENTS) && ifp->if_height) {
 		xfs_iext_destroy(ifp);
 	}
-	ASSERT(ifp->if_u1.if_extents == NULL ||
-	       ifp->if_u1.if_extents == ifp->if_u2.if_inline_ext);
+
 	ASSERT(ifp->if_real_bytes == 0);
+
 	if (whichfork == XFS_ATTR_FORK) {
 		kmem_zone_free(xfs_ifork_zone, ip->i_afp);
 		ip->i_afp = NULL;
···
 	}
 }
 
-/* Count number of incore extents based on if_bytes */
-xfs_extnum_t
-xfs_iext_count(struct xfs_ifork *ifp)
-{
-	return ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
-}
-
 /*
  * Convert in-core extents to on-disk form
- *
- * For either the data or attr fork in extent format, we need to endian convert
- * the in-core extent as we place them into the on-disk inode.
  *
  * In the case of the data fork, the in-core and on-disk fork sizes can be
  * different due to delayed allocation extents. We only copy on-disk extents
···
  */
 int
 xfs_iextents_copy(
-	xfs_inode_t		*ip,
-	xfs_bmbt_rec_t		*dp,
+	struct xfs_inode	*ip,
+	struct xfs_bmbt_rec	*dp,
 	int			whichfork)
 {
-	int			copied;
-	int			i;
-	xfs_ifork_t		*ifp;
-	int			nrecs;
-	xfs_fsblock_t		start_block;
+	int			state = xfs_bmap_fork_to_state(whichfork);
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	struct xfs_iext_cursor	icur;
+	struct xfs_bmbt_irec	rec;
+	int			copied = 0;
 
-	ifp = XFS_IFORK_PTR(ip, whichfork);
-	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
 	ASSERT(ifp->if_bytes > 0);
 
-	nrecs = xfs_iext_count(ifp);
-	XFS_BMAP_TRACE_EXLIST(ip, nrecs, whichfork);
-	ASSERT(nrecs > 0);
-
-	/*
-	 * There are some delayed allocation extents in the
-	 * inode, so copy the extents one at a time and skip
-	 * the delayed ones.  There must be at least one
-	 * non-delayed extent.
-	 */
-	copied = 0;
-	for (i = 0; i < nrecs; i++) {
-		xfs_bmbt_rec_host_t *ep = xfs_iext_get_ext(ifp, i);
-
-		ASSERT(xfs_bmbt_validate_extent(ip->i_mount, whichfork, ep));
-
-		start_block = xfs_bmbt_get_startblock(ep);
-		if (isnullstartblock(start_block)) {
-			/*
-			 * It's a delayed allocation extent, so skip it.
-			 */
+	for_each_xfs_iext(ifp, &icur, &rec) {
+		if (isnullstartblock(rec.br_startblock))
 			continue;
-		}
-
-		/* Translate to on disk format */
-		put_unaligned_be64(ep->l0, &dp->l0);
-		put_unaligned_be64(ep->l1, &dp->l1);
+		ASSERT(xfs_bmbt_validate_extent(ip->i_mount, whichfork, &rec));
+		xfs_bmbt_disk_set_all(dp, &rec);
+		trace_xfs_write_extent(ip, &icur, state, _RET_IP_);
+		copied += sizeof(struct xfs_bmbt_rec);
 		dp++;
-		copied++;
 	}
-	ASSERT(copied != 0);
 
-	return (copied * (uint)sizeof(xfs_bmbt_rec_t));
+	ASSERT(copied > 0);
+	ASSERT(copied <= ifp->if_bytes);
+	return copied;
 }
 
 /*
···
 		       !(iip->ili_fields & extflag[whichfork]));
 		if ((iip->ili_fields & extflag[whichfork]) &&
 		    (ifp->if_bytes > 0)) {
-			ASSERT(xfs_iext_get_ext(ifp, 0));
 			ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) > 0);
 			(void)xfs_iextents_copy(ip, (xfs_bmbt_rec_t *)cp,
 				whichfork);
···
 	case XFS_DINODE_FMT_DEV:
 		if (iip->ili_fields & XFS_ILOG_DEV) {
 			ASSERT(whichfork == XFS_DATA_FORK);
-			xfs_dinode_put_rdev(dip, ip->i_df.if_u2.if_rdev);
-		}
-		break;
-
-	case XFS_DINODE_FMT_UUID:
-		if (iip->ili_fields & XFS_ILOG_UUID) {
-			ASSERT(whichfork == XFS_DATA_FORK);
-			memcpy(XFS_DFORK_DPTR(dip),
-			       &ip->i_df.if_u2.if_uuid,
-			       sizeof(uuid_t));
+			xfs_dinode_put_rdev(dip, sysv_encode_dev(VFS_I(ip)->i_rdev));
 		}
 		break;
 
 	default:
 		ASSERT(0);
 		break;
-	}
-}
-
-/*
- * Return a pointer to the extent record at file index idx.
- */
-xfs_bmbt_rec_host_t *
-xfs_iext_get_ext(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_extnum_t	idx)		/* index of target extent */
-{
-	ASSERT(idx >= 0);
-	ASSERT(idx < xfs_iext_count(ifp));
-
-	if ((ifp->if_flags & XFS_IFEXTIREC) && (idx == 0)) {
-		return ifp->if_u1.if_ext_irec->er_extbuf;
-	} else if (ifp->if_flags & XFS_IFEXTIREC) {
-		xfs_ext_irec_t	*erp;		/* irec pointer */
-		int		erp_idx = 0;	/* irec index */
-		xfs_extnum_t	page_idx = idx;	/* ext index in target list */
-
-		erp = xfs_iext_idx_to_irec(ifp, &page_idx, &erp_idx, 0);
-		return &erp->er_extbuf[page_idx];
-	} else if (ifp->if_bytes) {
-		return &ifp->if_u1.if_extents[idx];
-	} else {
-		return NULL;
 	}
 }
 
···
 }
 
 /*
- * Insert new item(s) into the extent records for incore inode
- * fork 'ifp'.  'count' new items are inserted at index 'idx'.
- */
-void
-xfs_iext_insert(
-	xfs_inode_t	*ip,		/* incore inode pointer */
-	xfs_extnum_t	idx,		/* starting index of new items */
-	xfs_extnum_t	count,		/* number of inserted items */
-	xfs_bmbt_irec_t	*new,		/* items to insert */
-	int		state)		/* type of extent conversion */
-{
-	xfs_ifork_t	*ifp = xfs_iext_state_to_fork(ip, state);
-	xfs_extnum_t	i;		/* extent record index */
-
-	trace_xfs_iext_insert(ip, idx, new, state, _RET_IP_);
-
-	ASSERT(ifp->if_flags & XFS_IFEXTENTS);
-	xfs_iext_add(ifp, idx, count);
-	for (i = idx; i < idx + count; i++, new++)
-		xfs_bmbt_set_all(xfs_iext_get_ext(ifp, i), new);
-}
-
-/*
- * This is called when the amount of space required for incore file
- * extents needs to be increased. The ext_diff parameter stores the
- * number of new extents being added and the idx parameter contains
- * the extent index where the new extents will be added. If the new
- * extents are being appended, then we just need to (re)allocate and
- * initialize the space. Otherwise, if the new extents are being
- * inserted into the middle of the existing entries, a bit more work
- * is required to make room for the new extents to be inserted. The
- * caller is responsible for filling in the new extent entries upon
- * return.
- */
-void
-xfs_iext_add(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_extnum_t	idx,		/* index to begin adding exts */
-	int		ext_diff)	/* number of extents to add */
-{
-	int		byte_diff;	/* new bytes being added */
-	int		new_size;	/* size of extents after adding */
-	xfs_extnum_t	nextents;	/* number of extents in file */
-
-	nextents = xfs_iext_count(ifp);
-	ASSERT((idx >= 0) && (idx <= nextents));
-	byte_diff = ext_diff * sizeof(xfs_bmbt_rec_t);
-	new_size = ifp->if_bytes + byte_diff;
-	/*
-	 * If the new number of extents (nextents + ext_diff)
-	 * fits inside the inode, then continue to use the inline
-	 * extent buffer.
-	 */
-	if (nextents + ext_diff <= XFS_INLINE_EXTS) {
-		if (idx < nextents) {
-			memmove(&ifp->if_u2.if_inline_ext[idx + ext_diff],
-				&ifp->if_u2.if_inline_ext[idx],
-				(nextents - idx) * sizeof(xfs_bmbt_rec_t));
-			memset(&ifp->if_u2.if_inline_ext[idx], 0, byte_diff);
-		}
-		ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
-		ifp->if_real_bytes = 0;
-	}
-	/*
-	 * Otherwise use a linear (direct) extent list.
-	 * If the extents are currently inside the inode,
-	 * xfs_iext_realloc_direct will switch us from
-	 * inline to direct extent allocation mode.
-	 */
-	else if (nextents + ext_diff <= XFS_LINEAR_EXTS) {
-		xfs_iext_realloc_direct(ifp, new_size);
-		if (idx < nextents) {
-			memmove(&ifp->if_u1.if_extents[idx + ext_diff],
-				&ifp->if_u1.if_extents[idx],
-				(nextents - idx) * sizeof(xfs_bmbt_rec_t));
-			memset(&ifp->if_u1.if_extents[idx], 0, byte_diff);
-		}
-	}
-	/* Indirection array */
-	else {
-		xfs_ext_irec_t	*erp;
-		int		erp_idx = 0;
-		int		page_idx = idx;
-
-		ASSERT(nextents + ext_diff > XFS_LINEAR_EXTS);
-		if (ifp->if_flags & XFS_IFEXTIREC) {
-			erp = xfs_iext_idx_to_irec(ifp, &page_idx, &erp_idx, 1);
-		} else {
-			xfs_iext_irec_init(ifp);
-			ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-			erp = ifp->if_u1.if_ext_irec;
-		}
-		/* Extents fit in target extent page */
-		if (erp && erp->er_extcount + ext_diff <= XFS_LINEAR_EXTS) {
-			if (page_idx < erp->er_extcount) {
-				memmove(&erp->er_extbuf[page_idx + ext_diff],
-					&erp->er_extbuf[page_idx],
-					(erp->er_extcount - page_idx) *
-					sizeof(xfs_bmbt_rec_t));
-				memset(&erp->er_extbuf[page_idx], 0, byte_diff);
-			}
-			erp->er_extcount += ext_diff;
-			xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff);
-		}
-		/* Insert a new extent page */
-		else if (erp) {
-			xfs_iext_add_indirect_multi(ifp,
-				erp_idx, page_idx, ext_diff);
-		}
-		/*
-		 * If extent(s) are being appended to the last page in
-		 * the indirection array and the new extent(s) don't fit
-		 * in the page, then erp is NULL and erp_idx is set to
-		 * the next index needed in the indirection array.
-		 */
-		else {
-			uint	count = ext_diff;
-
-			while (count) {
-				erp = xfs_iext_irec_new(ifp, erp_idx);
-				erp->er_extcount = min(count, XFS_LINEAR_EXTS);
-				count -= erp->er_extcount;
-				if (count)
-					erp_idx++;
-			}
-		}
-	}
-	ifp->if_bytes = new_size;
-}
-
-/*
- * This is called when incore extents are being added to the indirection
- * array and the new extents do not fit in the target extent list. The
- * erp_idx parameter contains the irec index for the target extent list
- * in the indirection array, and the idx parameter contains the extent
- * index within the list. The number of extents being added is stored
- * in the count parameter.
- *
- *    |-------|   |-------|
- *    |       |   |       |    idx - number of extents before idx
- *    |  idx  |   | count |
- *    |       |   |       |    count - number of extents being inserted at idx
- *    |-------|   |-------|
- *    | count |   | nex2  |    nex2 - number of extents after idx + count
- *    |-------|   |-------|
- */
-void
-xfs_iext_add_indirect_multi(
-	xfs_ifork_t	*ifp,			/* inode fork pointer */
-	int		erp_idx,		/* target extent irec index */
-	xfs_extnum_t	idx,			/* index within target list */
-	int		count)			/* new extents being added */
-{
-	int		byte_diff;		/* new bytes being added */
-	xfs_ext_irec_t	*erp;			/* pointer to irec entry */
-	xfs_extnum_t	ext_diff;		/* number of extents to add */
-	xfs_extnum_t	ext_cnt;		/* new extents still needed */
-	xfs_extnum_t	nex2;			/* extents after idx + count */
-	xfs_bmbt_rec_t	*nex2_ep = NULL;	/* temp list for nex2 extents */
-	int		nlists;			/* number of irec's (lists) */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	erp = &ifp->if_u1.if_ext_irec[erp_idx];
-	nex2 = erp->er_extcount - idx;
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-
-	/*
-	 * Save second part of target extent list
-	 * (all extents past */
-	if (nex2) {
-		byte_diff = nex2 * sizeof(xfs_bmbt_rec_t);
-		nex2_ep = (xfs_bmbt_rec_t *) kmem_alloc(byte_diff, KM_NOFS);
-		memmove(nex2_ep, &erp->er_extbuf[idx], byte_diff);
-		erp->er_extcount -= nex2;
-		xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, -nex2);
-		memset(&erp->er_extbuf[idx], 0, byte_diff);
-	}
-
-	/*
-	 * Add the new extents to the end of the target
-	 * list, then allocate new irec record(s) and
-	 * extent buffer(s) as needed to store the rest
-	 * of the new extents.
-	 */
-	ext_cnt = count;
-	ext_diff = MIN(ext_cnt, (int)XFS_LINEAR_EXTS - erp->er_extcount);
-	if (ext_diff) {
-		erp->er_extcount += ext_diff;
-		xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff);
-		ext_cnt -= ext_diff;
-	}
-	while (ext_cnt) {
-		erp_idx++;
-		erp = xfs_iext_irec_new(ifp, erp_idx);
-		ext_diff = MIN(ext_cnt, (int)XFS_LINEAR_EXTS);
-		erp->er_extcount = ext_diff;
-		xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, ext_diff);
-		ext_cnt -= ext_diff;
-	}
-
-	/* Add nex2 extents back to indirection array */
-	if (nex2) {
-		xfs_extnum_t	ext_avail;
-		int		i;
-
-		byte_diff = nex2 * sizeof(xfs_bmbt_rec_t);
-		ext_avail = XFS_LINEAR_EXTS - erp->er_extcount;
-		i = 0;
-		/*
-		 * If nex2 extents fit in the current page, append
-		 * nex2_ep after the new extents.
-		 */
-		if (nex2 <= ext_avail) {
-			i = erp->er_extcount;
-		}
-		/*
-		 * Otherwise, check if space is available in the
-		 * next page.
-		 */
-		else if ((erp_idx < nlists - 1) &&
-			 (nex2 <= (ext_avail = XFS_LINEAR_EXTS -
-			  ifp->if_u1.if_ext_irec[erp_idx+1].er_extcount))) {
-			erp_idx++;
-			erp++;
-			/* Create a hole for nex2 extents */
-			memmove(&erp->er_extbuf[nex2], erp->er_extbuf,
-				erp->er_extcount * sizeof(xfs_bmbt_rec_t));
-		}
-		/*
-		 * Final choice, create a new extent page for
-		 * nex2 extents.
-		 */
-		else {
-			erp_idx++;
-			erp = xfs_iext_irec_new(ifp, erp_idx);
-		}
-		memmove(&erp->er_extbuf[i], nex2_ep, byte_diff);
-		kmem_free(nex2_ep);
-		erp->er_extcount += nex2;
-		xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, nex2);
-	}
-}
-
-/*
- * This is called when the amount of space required for incore file
- * extents needs to be decreased. The ext_diff parameter stores the
- * number of extents to be removed and the idx parameter contains
- * the extent index where the extents will be removed from.
- *
- * If the amount of space needed has decreased below the linear
- * limit, XFS_IEXT_BUFSZ, then switch to using the contiguous
- * extent array.  Otherwise, use kmem_realloc() to adjust the
- * size to what is needed.
- */
-void
-xfs_iext_remove(
-	xfs_inode_t	*ip,		/* incore inode pointer */
-	xfs_extnum_t	idx,		/* index to begin removing exts */
-	int		ext_diff,	/* number of extents to remove */
-	int		state)		/* type of extent conversion */
-{
-	xfs_ifork_t	*ifp = xfs_iext_state_to_fork(ip, state);
-	xfs_extnum_t	nextents;	/* number of extents in file */
-	int		new_size;	/* size of extents after removal */
-
-	trace_xfs_iext_remove(ip, idx, state, _RET_IP_);
-
-	ASSERT(ext_diff > 0);
-	nextents = xfs_iext_count(ifp);
-	new_size = (nextents - ext_diff) * sizeof(xfs_bmbt_rec_t);
-
-	if (new_size == 0) {
-		xfs_iext_destroy(ifp);
-	} else if (ifp->if_flags & XFS_IFEXTIREC) {
-		xfs_iext_remove_indirect(ifp, idx, ext_diff);
-	} else if (ifp->if_real_bytes) {
-		xfs_iext_remove_direct(ifp, idx, ext_diff);
-	} else {
-		xfs_iext_remove_inline(ifp, idx, ext_diff);
-	}
-	ifp->if_bytes = new_size;
-}
-
-/*
- * This removes ext_diff extents from the inline buffer, beginning
- * at extent index idx.
- */
-void
-xfs_iext_remove_inline(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_extnum_t	idx,		/* index to begin removing exts */
-	int		ext_diff)	/* number of extents to remove */
-{
-	int		nextents;	/* number of extents in file */
-
-	ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
-	ASSERT(idx < XFS_INLINE_EXTS);
-	nextents = xfs_iext_count(ifp);
-	ASSERT(((nextents - ext_diff) > 0) &&
-		(nextents - ext_diff) < XFS_INLINE_EXTS);
-
-	if (idx + ext_diff < nextents) {
-		memmove(&ifp->if_u2.if_inline_ext[idx],
-			&ifp->if_u2.if_inline_ext[idx + ext_diff],
-			(nextents - (idx + ext_diff)) *
-			 sizeof(xfs_bmbt_rec_t));
-		memset(&ifp->if_u2.if_inline_ext[nextents - ext_diff],
-			0, ext_diff * sizeof(xfs_bmbt_rec_t));
-	} else {
-		memset(&ifp->if_u2.if_inline_ext[idx], 0,
-			ext_diff * sizeof(xfs_bmbt_rec_t));
-	}
-}
-
-/*
- * This removes ext_diff extents from a linear (direct) extent list,
- * beginning at extent index idx. If the extents are being removed
- * from the end of the list (ie. truncate) then we just need to re-
- * allocate the list to remove the extra space. Otherwise, if the
- * extents are being removed from the middle of the existing extent
- * entries, then we first need to move the extent records beginning
- * at idx + ext_diff up in the list to overwrite the records being
- * removed, then remove the extra space via kmem_realloc.
- */
-void
-xfs_iext_remove_direct(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_extnum_t	idx,		/* index to begin removing exts */
-	int		ext_diff)	/* number of extents to remove */
-{
-	xfs_extnum_t	nextents;	/* number of extents in file */
-	int		new_size;	/* size of extents after removal */
-
-	ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
-	new_size = ifp->if_bytes -
-		(ext_diff * sizeof(xfs_bmbt_rec_t));
-	nextents = xfs_iext_count(ifp);
-
-	if (new_size == 0) {
-		xfs_iext_destroy(ifp);
-		return;
-	}
-	/* Move extents up in the list (if needed) */
-	if (idx + ext_diff < nextents) {
-		memmove(&ifp->if_u1.if_extents[idx],
-			&ifp->if_u1.if_extents[idx + ext_diff],
-			(nextents - (idx + ext_diff)) *
-			 sizeof(xfs_bmbt_rec_t));
-	}
-	memset(&ifp->if_u1.if_extents[nextents - ext_diff],
-		0, ext_diff * sizeof(xfs_bmbt_rec_t));
-	/*
-	 * Reallocate the direct extent list. If the extents
-	 * will fit inside the inode then xfs_iext_realloc_direct
-	 * will switch from direct to inline extent allocation
-	 * mode for us.
-	 */
-	xfs_iext_realloc_direct(ifp, new_size);
-	ifp->if_bytes = new_size;
-}
-
-/*
- * This is called when incore extents are being removed from the
- * indirection array and the extents being removed span multiple extent
- * buffers. The idx parameter contains the file extent index where we
- * want to begin removing extents, and the count parameter contains
- * how many extents need to be removed.
- *
- *    |-------|   |-------|
- *    | nex1  |   |       |    nex1 - number of extents before idx
- *    |-------|   | count |
- *    |       |   |       |    count - number of extents being removed at idx
- *    | count |   |-------|
- *    |       |   | nex2  |    nex2 - number of extents after idx + count
- *    |-------|   |-------|
- */
-void
-xfs_iext_remove_indirect(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_extnum_t	idx,		/* index to begin removing extents */
-	int		count)		/* number of extents to remove */
-{
-	xfs_ext_irec_t	*erp;		/* indirection array pointer */
-	int		erp_idx = 0;	/* indirection array index */
-	xfs_extnum_t	ext_cnt;	/* extents left to remove */
-	xfs_extnum_t	ext_diff;	/* extents to remove in current list */
-	xfs_extnum_t	nex1;		/* number of extents before idx */
-	xfs_extnum_t	nex2;		/* extents after idx + count */
-	int		page_idx = idx;	/* index in target extent list */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	erp = xfs_iext_idx_to_irec(ifp,  &page_idx, &erp_idx, 0);
-	ASSERT(erp != NULL);
-	nex1 = page_idx;
-	ext_cnt = count;
-	while (ext_cnt) {
-		nex2 = MAX((erp->er_extcount - (nex1 + ext_cnt)), 0);
-		ext_diff = MIN(ext_cnt, (erp->er_extcount - nex1));
-		/*
-		 * Check for deletion of entire list;
-		 * xfs_iext_irec_remove() updates extent offsets.
-		 */
-		if (ext_diff == erp->er_extcount) {
-			xfs_iext_irec_remove(ifp, erp_idx);
-			ext_cnt -= ext_diff;
-			nex1 = 0;
-			if (ext_cnt) {
-				ASSERT(erp_idx < ifp->if_real_bytes /
-					XFS_IEXT_BUFSZ);
-				erp = &ifp->if_u1.if_ext_irec[erp_idx];
-				nex1 = 0;
-				continue;
-			} else {
-				break;
-			}
-		}
-		/* Move extents up (if needed) */
-		if (nex2) {
-			memmove(&erp->er_extbuf[nex1],
-				&erp->er_extbuf[nex1 + ext_diff],
-				nex2 * sizeof(xfs_bmbt_rec_t));
-		}
-		/* Zero out rest of page */
-		memset(&erp->er_extbuf[nex1 + nex2], 0, (XFS_IEXT_BUFSZ -
-			((nex1 + nex2) * sizeof(xfs_bmbt_rec_t))));
-		/* Update remaining counters */
-		erp->er_extcount -= ext_diff;
-		xfs_iext_irec_update_extoffs(ifp, erp_idx + 1, -ext_diff);
-		ext_cnt -= ext_diff;
-		nex1 = 0;
-		erp_idx++;
-		erp++;
-	}
-	ifp->if_bytes -= count * sizeof(xfs_bmbt_rec_t);
-	xfs_iext_irec_compact(ifp);
-}
-
-/*
- * Create, destroy, or resize a linear (direct) block of extents.
- */
-void
-xfs_iext_realloc_direct(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	int		new_size)	/* new size of extents after adding */
-{
-	int		rnew_size;	/* real new size of extents */
-
-	rnew_size = new_size;
-
-	ASSERT(!(ifp->if_flags & XFS_IFEXTIREC) ||
-		((new_size >= 0) && (new_size <= XFS_IEXT_BUFSZ) &&
-		 (new_size != ifp->if_real_bytes)));
-
-	/* Free extent records */
-	if (new_size == 0) {
-		xfs_iext_destroy(ifp);
-	}
-	/* Resize direct extent list and zero any new bytes */
-	else if (ifp->if_real_bytes) {
-		/* Check if extents will fit inside the inode */
-		if (new_size <= XFS_INLINE_EXTS * sizeof(xfs_bmbt_rec_t)) {
-			xfs_iext_direct_to_inline(ifp, new_size /
-				(uint)sizeof(xfs_bmbt_rec_t));
-			ifp->if_bytes = new_size;
-			return;
-		}
-		if (!is_power_of_2(new_size)){
-			rnew_size = roundup_pow_of_two(new_size);
-		}
-		if (rnew_size != ifp->if_real_bytes) {
-			ifp->if_u1.if_extents =
-				kmem_realloc(ifp->if_u1.if_extents,
-						rnew_size, KM_NOFS);
-		}
-		if (rnew_size > ifp->if_real_bytes) {
-			memset(&ifp->if_u1.if_extents[ifp->if_bytes /
-				(uint)sizeof(xfs_bmbt_rec_t)], 0,
-				rnew_size - ifp->if_real_bytes);
-		}
-	}
-	/* Switch from the inline extent buffer to a direct extent list */
-	else {
-		if (!is_power_of_2(new_size)) {
-			rnew_size = roundup_pow_of_two(new_size);
-		}
-		xfs_iext_inline_to_direct(ifp, rnew_size);
-	}
-	ifp->if_real_bytes = rnew_size;
-	ifp->if_bytes = new_size;
-}
-
-/*
- * Switch from linear (direct) extent records to inline buffer.
- */
-void
-xfs_iext_direct_to_inline(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_extnum_t	nextents)	/* number of extents in file */
-{
-	ASSERT(ifp->if_flags & XFS_IFEXTENTS);
-	ASSERT(nextents <= XFS_INLINE_EXTS);
-	/*
-	 * The inline buffer was zeroed when we switched
-	 * from inline to direct extent allocation mode,
-	 * so we don't need to clear it here.
-	 */
-	memcpy(ifp->if_u2.if_inline_ext, ifp->if_u1.if_extents,
-		nextents * sizeof(xfs_bmbt_rec_t));
-	kmem_free(ifp->if_u1.if_extents);
-	ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
-	ifp->if_real_bytes = 0;
-}
-
-/*
- * Switch from inline buffer to linear (direct) extent records.
- * new_size should already be rounded up to the next power of 2
- * by the caller (when appropriate), so use new_size as it is.
- * However, since new_size may be rounded up, we can't update
- * if_bytes here. It is the caller's responsibility to update
- * if_bytes upon return.
- */
-void
-xfs_iext_inline_to_direct(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	int		new_size)	/* number of extents in file */
-{
-	ifp->if_u1.if_extents = kmem_alloc(new_size, KM_NOFS);
-	memset(ifp->if_u1.if_extents, 0, new_size);
-	if (ifp->if_bytes) {
-		memcpy(ifp->if_u1.if_extents, ifp->if_u2.if_inline_ext,
-			ifp->if_bytes);
-		memset(ifp->if_u2.if_inline_ext, 0, XFS_INLINE_EXTS *
-			sizeof(xfs_bmbt_rec_t));
-	}
-	ifp->if_real_bytes = new_size;
-}
-
-/*
- * Resize an extent indirection array to new_size bytes.
- */
-STATIC void
-xfs_iext_realloc_indirect(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	int		new_size)	/* new indirection array size */
-{
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	ASSERT(ifp->if_real_bytes);
-	ASSERT((new_size >= 0) &&
-	       (new_size != ((ifp->if_real_bytes / XFS_IEXT_BUFSZ) *
-			     sizeof(xfs_ext_irec_t))));
-	if (new_size == 0) {
-		xfs_iext_destroy(ifp);
-	} else {
-		ifp->if_u1.if_ext_irec =
-			kmem_realloc(ifp->if_u1.if_ext_irec, new_size, KM_NOFS);
-	}
-}
-
-/*
- * Switch from indirection array to linear (direct) extent allocations.
- */
-STATIC void
-xfs_iext_indirect_to_direct(
-	 xfs_ifork_t	*ifp)		/* inode fork pointer */
-{
-	xfs_bmbt_rec_host_t *ep;	/* extent record pointer */
-	xfs_extnum_t	nextents;	/* number of extents in file */
-	int		size;		/* size of file extents */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nextents = xfs_iext_count(ifp);
-	ASSERT(nextents <= XFS_LINEAR_EXTS);
-	size = nextents * sizeof(xfs_bmbt_rec_t);
-
-	xfs_iext_irec_compact_pages(ifp);
-	ASSERT(ifp->if_real_bytes == XFS_IEXT_BUFSZ);
-
-	ep = ifp->if_u1.if_ext_irec->er_extbuf;
-	kmem_free(ifp->if_u1.if_ext_irec);
-	ifp->if_flags &= ~XFS_IFEXTIREC;
-	ifp->if_u1.if_extents = ep;
-	ifp->if_bytes = size;
-	if (nextents < XFS_LINEAR_EXTS) {
-		xfs_iext_realloc_direct(ifp, size);
-	}
-}
-
-/*
- * Remove all records from the indirection array.
- */
-STATIC void
-xfs_iext_irec_remove_all(
-	struct xfs_ifork *ifp)
-{
-	int		nlists;
-	int		i;
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-	for (i = 0; i < nlists; i++)
-		kmem_free(ifp->if_u1.if_ext_irec[i].er_extbuf);
-	kmem_free(ifp->if_u1.if_ext_irec);
-	ifp->if_flags &= ~XFS_IFEXTIREC;
-}
-
-/*
- * Free incore file extents.
- */
-void
-xfs_iext_destroy(
-	xfs_ifork_t	*ifp)		/* inode fork pointer */
-{
-	if (ifp->if_flags & XFS_IFEXTIREC) {
-		xfs_iext_irec_remove_all(ifp);
-	} else if (ifp->if_real_bytes) {
-		kmem_free(ifp->if_u1.if_extents);
-	} else if (ifp->if_bytes) {
-		memset(ifp->if_u2.if_inline_ext, 0, XFS_INLINE_EXTS *
-			sizeof(xfs_bmbt_rec_t));
-	}
-	ifp->if_u1.if_extents = NULL;
-	ifp->if_real_bytes = 0;
-	ifp->if_bytes = 0;
-}
-
-/*
- * Return a pointer to the extent record for file system block bno.
- */
-xfs_bmbt_rec_host_t *			/* pointer to found extent record */
-xfs_iext_bno_to_ext(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_fileoff_t	bno,		/* block number to search for */
-	xfs_extnum_t	*idxp)		/* index of target extent */
-{
-	xfs_bmbt_rec_host_t *base;	/* pointer to first extent */
-	xfs_filblks_t	blockcount = 0;	/* number of blocks in extent */
-	xfs_bmbt_rec_host_t *ep = NULL;	/* pointer to target extent */
-	xfs_ext_irec_t	*erp = NULL;	/* indirection array pointer */
-	int		high;		/* upper boundary in search */
-	xfs_extnum_t	idx = 0;	/* index of target extent */
-	int		low;		/* lower boundary in search */
-	xfs_extnum_t	nextents;	/* number of file extents */
-	xfs_fileoff_t	startoff = 0;	/* start offset of extent */
-
-	nextents = xfs_iext_count(ifp);
-	if (nextents == 0) {
-		*idxp = 0;
-		return NULL;
-	}
-	low = 0;
-	if (ifp->if_flags & XFS_IFEXTIREC) {
-		/* Find target extent list */
-		int	erp_idx = 0;
-		erp = xfs_iext_bno_to_irec(ifp, bno, &erp_idx);
-		base = erp->er_extbuf;
-		high = erp->er_extcount - 1;
-	} else {
-		base = ifp->if_u1.if_extents;
-		high = nextents - 1;
-	}
-	/* Binary search extent records */
-	while (low <= high) {
-		idx = (low + high) >> 1;
-		ep = base + idx;
-		startoff = xfs_bmbt_get_startoff(ep);
-		blockcount = xfs_bmbt_get_blockcount(ep);
-		if (bno < startoff) {
-			high = idx - 1;
-		} else if (bno >= startoff + blockcount) {
-			low = idx + 1;
-		} else {
-			/* Convert back to file-based extent index */
-			if (ifp->if_flags & XFS_IFEXTIREC) {
-				idx += erp->er_extoff;
-			}
-			*idxp = idx;
-			return ep;
-		}
-	}
-	/* Convert back to file-based extent index */
-	if (ifp->if_flags & XFS_IFEXTIREC) {
-		idx += erp->er_extoff;
-	}
-	if (bno >= startoff + blockcount) {
-		if (++idx == nextents) {
-			ep = NULL;
-		} else {
-			ep = xfs_iext_get_ext(ifp, idx);
-		}
-	}
-	*idxp = idx;
-	return ep;
-}
-
-/*
- * Return a pointer to the indirection array entry containing the
- * extent record for filesystem block bno. Store the index of the
- * target irec in *erp_idxp.
- */
-xfs_ext_irec_t *			/* pointer to found extent record */
-xfs_iext_bno_to_irec(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_fileoff_t	bno,		/* block number to search for */
-	int		*erp_idxp)	/* irec index of target ext list */
-{
-	xfs_ext_irec_t	*erp = NULL;	/* indirection array pointer */
-	xfs_ext_irec_t	*erp_next;	/* next indirection array entry */
-	int		erp_idx;	/* indirection array index */
-	int		nlists;		/* number of extent irec's (lists) */
-	int		high;		/* binary search upper limit */
-	int		low;		/* binary search lower limit */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-	erp_idx = 0;
-	low = 0;
-	high = nlists - 1;
-	while (low <= high) {
-		erp_idx = (low + high) >> 1;
-		erp = &ifp->if_u1.if_ext_irec[erp_idx];
-		erp_next = erp_idx < nlists - 1 ? erp + 1 : NULL;
-		if (bno < xfs_bmbt_get_startoff(erp->er_extbuf)) {
-			high = erp_idx - 1;
-		} else if (erp_next && bno >=
-			   xfs_bmbt_get_startoff(erp_next->er_extbuf)) {
-			low = erp_idx + 1;
-		} else {
-			break;
-		}
-	}
-	*erp_idxp = erp_idx;
-	return erp;
-}
-
-/*
- * Return a pointer to the indirection array entry containing the
- * extent record at file extent index *idxp. Store the index of the
- * target irec in *erp_idxp and store the page index of the target
- * extent record in *idxp.
- */
-xfs_ext_irec_t *
-xfs_iext_idx_to_irec(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	xfs_extnum_t	*idxp,		/* extent index (file -> page) */
-	int		*erp_idxp,	/* pointer to target irec */
-	int		realloc)	/* new bytes were just added */
-{
-	xfs_ext_irec_t	*prev;		/* pointer to previous irec */
-	xfs_ext_irec_t	*erp = NULL;	/* pointer to current irec */
-	int		erp_idx;	/* indirection array index */
-	int		nlists;		/* number of irec's (ex lists) */
-	int		high;		/* binary search upper limit */
-	int		low;		/* binary search lower limit */
-	xfs_extnum_t	page_idx = *idxp; /* extent index in target list */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	ASSERT(page_idx >= 0);
-	ASSERT(page_idx <= xfs_iext_count(ifp));
-	ASSERT(page_idx < xfs_iext_count(ifp) || realloc);
-
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-	erp_idx = 0;
-	low = 0;
-	high = nlists - 1;
-
-	/* Binary search extent irec's */
-	while (low <= high) {
-		erp_idx = (low + high) >> 1;
-		erp = &ifp->if_u1.if_ext_irec[erp_idx];
-		prev = erp_idx > 0 ? erp - 1 : NULL;
-		if (page_idx < erp->er_extoff || (page_idx == erp->er_extoff &&
-		     realloc && prev && prev->er_extcount < XFS_LINEAR_EXTS)) {
-			high = erp_idx - 1;
-		} else if (page_idx > erp->er_extoff + erp->er_extcount ||
-			   (page_idx == erp->er_extoff + erp->er_extcount &&
-			    !realloc)) {
-			low = erp_idx + 1;
-		} else if (page_idx == erp->er_extoff + erp->er_extcount &&
-			   erp->er_extcount == XFS_LINEAR_EXTS) {
-			ASSERT(realloc);
-			page_idx = 0;
-			erp_idx++;
-			erp = erp_idx < nlists ? erp + 1 : NULL;
-			break;
-		} else {
-			page_idx -= erp->er_extoff;
-			break;
-		}
-	}
-	*idxp = page_idx;
-	*erp_idxp = erp_idx;
-	return erp;
-}
-
-/*
- * Allocate and initialize an indirection array once the space needed
- * for incore extents increases above XFS_IEXT_BUFSZ.
- */
-void
-xfs_iext_irec_init(
-	xfs_ifork_t	*ifp)		/* inode fork pointer */
-{
-	xfs_ext_irec_t	*erp;		/* indirection array pointer */
-	xfs_extnum_t	nextents;	/* number of extents in file */
-
-	ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
-	nextents = xfs_iext_count(ifp);
-	ASSERT(nextents <= XFS_LINEAR_EXTS);
-
-	erp = kmem_alloc(sizeof(xfs_ext_irec_t), KM_NOFS);
-
-	if (nextents == 0) {
-		ifp->if_u1.if_extents = kmem_alloc(XFS_IEXT_BUFSZ, KM_NOFS);
-	} else if (!ifp->if_real_bytes) {
-		xfs_iext_inline_to_direct(ifp, XFS_IEXT_BUFSZ);
-	} else if (ifp->if_real_bytes < XFS_IEXT_BUFSZ) {
-		xfs_iext_realloc_direct(ifp, XFS_IEXT_BUFSZ);
-	}
-	erp->er_extbuf = ifp->if_u1.if_extents;
-	erp->er_extcount = nextents;
-	erp->er_extoff = 0;
-
-	ifp->if_flags |= XFS_IFEXTIREC;
-	ifp->if_real_bytes = XFS_IEXT_BUFSZ;
-	ifp->if_bytes = nextents * sizeof(xfs_bmbt_rec_t);
-	ifp->if_u1.if_ext_irec = erp;
-
-	return;
-}
-
-/*
- * Allocate and initialize a new entry in the indirection array.
- */
-xfs_ext_irec_t *
-xfs_iext_irec_new(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	int		erp_idx)	/* index for new irec */
-{
-	xfs_ext_irec_t	*erp;		/* indirection array pointer */
-	int		i;		/* loop counter */
-	int		nlists;		/* number of irec's (ex lists) */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-
-	/* Resize indirection array */
-	xfs_iext_realloc_indirect(ifp, ++nlists *
-				  sizeof(xfs_ext_irec_t));
-	/*
-	 * Move records down in the array so the
-	 * new page can use erp_idx.
-	 */
-	erp = ifp->if_u1.if_ext_irec;
-	for (i = nlists - 1; i > erp_idx; i--) {
-		memmove(&erp[i], &erp[i-1], sizeof(xfs_ext_irec_t));
-	}
-	ASSERT(i == erp_idx);
-
-	/* Initialize new extent record */
-	erp = ifp->if_u1.if_ext_irec;
-	erp[erp_idx].er_extbuf = kmem_alloc(XFS_IEXT_BUFSZ, KM_NOFS);
-	ifp->if_real_bytes = nlists * XFS_IEXT_BUFSZ;
-	memset(erp[erp_idx].er_extbuf, 0, XFS_IEXT_BUFSZ);
-	erp[erp_idx].er_extcount = 0;
-	erp[erp_idx].er_extoff = erp_idx > 0 ?
-		erp[erp_idx-1].er_extoff + erp[erp_idx-1].er_extcount : 0;
-	return (&erp[erp_idx]);
-}
-
-/*
- * Remove a record from the indirection array.
- */
-void
-xfs_iext_irec_remove(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	int		erp_idx)	/* irec index to remove */
-{
-	xfs_ext_irec_t	*erp;		/* indirection array pointer */
-	int		i;		/* loop counter */
-	int		nlists;		/* number of irec's (ex lists) */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-	erp = &ifp->if_u1.if_ext_irec[erp_idx];
-	if (erp->er_extbuf) {
-		xfs_iext_irec_update_extoffs(ifp, erp_idx + 1,
-			-erp->er_extcount);
-		kmem_free(erp->er_extbuf);
-	}
-	/* Compact extent records */
-	erp = ifp->if_u1.if_ext_irec;
-	for (i = erp_idx; i < nlists - 1; i++) {
-		memmove(&erp[i], &erp[i+1], sizeof(xfs_ext_irec_t));
-	}
-	/*
-	 * Manually free the last extent record from the indirection
-	 * array.  A call to xfs_iext_realloc_indirect() with a size
-	 * of zero would result in a call to xfs_iext_destroy() which
-	 * would in turn call this function again, creating a nasty
-	 * infinite loop.
-	 */
-	if (--nlists) {
-		xfs_iext_realloc_indirect(ifp,
-			nlists * sizeof(xfs_ext_irec_t));
-	} else {
-		kmem_free(ifp->if_u1.if_ext_irec);
-	}
-	ifp->if_real_bytes = nlists * XFS_IEXT_BUFSZ;
-}
-
-/*
- * This is called to clean up large amounts of unused memory allocated
- * by the indirection array.  Before compacting anything though, verify
- * that the indirection array is still needed and switch back to the
- * linear extent list (or even the inline buffer) if possible.  The
- * compaction policy is as follows:
- *
- *    Full Compaction: Extents fit into a single page (or inline buffer)
- * Partial Compaction: Extents occupy less than 50% of allocated space
- *      No Compaction: Extents occupy at least 50% of allocated space
- */
-void
-xfs_iext_irec_compact(
-	xfs_ifork_t	*ifp)		/* inode fork pointer */
-{
-	xfs_extnum_t	nextents;	/* number of extents in file */
-	int		nlists;		/* number of irec's (ex lists) */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-	nextents = xfs_iext_count(ifp);
-
-	if (nextents == 0) {
-		xfs_iext_destroy(ifp);
-	} else if (nextents <= XFS_INLINE_EXTS) {
-		xfs_iext_indirect_to_direct(ifp);
-		xfs_iext_direct_to_inline(ifp, nextents);
-	} else if (nextents <= XFS_LINEAR_EXTS) {
-		xfs_iext_indirect_to_direct(ifp);
-	} else if (nextents < (nlists * XFS_LINEAR_EXTS) >> 1) {
-		xfs_iext_irec_compact_pages(ifp);
-	}
-}
-
-/*
- * Combine extents from neighboring extent pages.
- */
-void
-xfs_iext_irec_compact_pages(
-	xfs_ifork_t	*ifp)		/* inode fork pointer */
-{
-	xfs_ext_irec_t	*erp, *erp_next;/* pointers to irec entries */
-	int		erp_idx = 0;	/* indirection array index */
-	int		nlists;		/* number of irec's (ex lists) */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-	while (erp_idx < nlists - 1) {
-		erp = &ifp->if_u1.if_ext_irec[erp_idx];
-		erp_next = erp + 1;
-		if (erp_next->er_extcount <=
-		    (XFS_LINEAR_EXTS - erp->er_extcount)) {
-			memcpy(&erp->er_extbuf[erp->er_extcount],
-				erp_next->er_extbuf, erp_next->er_extcount *
-				sizeof(xfs_bmbt_rec_t));
-			erp->er_extcount += erp_next->er_extcount;
-			/*
-			 * Free page before removing extent record
-			 * so er_extoffs don't get modified in
-			 * xfs_iext_irec_remove.
-			 */
-			kmem_free(erp_next->er_extbuf);
-			erp_next->er_extbuf = NULL;
-			xfs_iext_irec_remove(ifp, erp_idx + 1);
-			nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-		} else {
-			erp_idx++;
-		}
-	}
-}
-
-/*
- * This is called to update the er_extoff field in the indirection
- * array when extents have been added or removed from one of the
- * extent lists. erp_idx contains the irec index to begin updating
- * at and ext_diff contains the number of extents that were added
- * or removed.
- */
-void
-xfs_iext_irec_update_extoffs(
-	xfs_ifork_t	*ifp,		/* inode fork pointer */
-	int		erp_idx,	/* irec index to update */
-	int		ext_diff)	/* number of new extents */
-{
-	int		i;		/* loop counter */
-	int		nlists;		/* number of irec's (ex lists */
-
-	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-	for (i = erp_idx; i < nlists; i++) {
-		ifp->if_u1.if_ext_irec[i].er_extoff += ext_diff;
-	}
-}
-
-/*
  * Initialize an inode's copy-on-write fork.
  */
 void
···
 	ip->i_cowfp->if_flags = XFS_IFEXTENTS;
 	ip->i_cformat = XFS_DINODE_FMT_EXTENTS;
 	ip->i_cnextents = 0;
-}
-
-/*
- * Lookup the extent covering bno.
- *
- * If there is an extent covering bno return the extent index, and store the
- * expanded extent structure in *gotp, and the extent index in *idx.
- * If there is no extent covering bno, but there is an extent after it (e.g.
- * it lies in a hole) return that extent in *gotp and its index in *idx
- * instead.
- * If bno is beyond the last extent return false, and return the index after
- * the last valid index in *idxp.
- */
-bool
-xfs_iext_lookup_extent(
-	struct xfs_inode	*ip,
-	struct xfs_ifork	*ifp,
-	xfs_fileoff_t		bno,
-	xfs_extnum_t		*idxp,
-	struct xfs_bmbt_irec	*gotp)
-{
-	struct xfs_bmbt_rec_host *ep;
-
-	XFS_STATS_INC(ip->i_mount, xs_look_exlist);
-
-	ep = xfs_iext_bno_to_ext(ifp, bno, idxp);
-	if (!ep)
-		return false;
-	xfs_bmbt_get_all(ep, gotp);
-	return true;
-}
-
-/*
- * Return true if there is an extent at index idx, and return the expanded
- * extent structure at idx in that case.  Else return false.
- */
-bool
-xfs_iext_get_extent(
-	struct xfs_ifork	*ifp,
-	xfs_extnum_t		idx,
-	struct xfs_bmbt_irec	*gotp)
-{
-	if (idx < 0 || idx >= xfs_iext_count(ifp))
-		return false;
-	xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), gotp);
-	return true;
-}
-
-void
-xfs_iext_update_extent(
-	struct xfs_ifork	*ifp,
-	xfs_extnum_t		idx,
-	struct xfs_bmbt_irec	*gotp)
-{
-	ASSERT(idx >= 0);
-	ASSERT(idx < xfs_iext_count(ifp));
-
-	xfs_bmbt_set_all(xfs_iext_get_ext(ifp, idx), gotp);
 }

fs/xfs/libxfs/xfs_inode_fork.h

···
 struct xfs_dinode;
 
 /*
- * The following xfs_ext_irec_t struct introduces a second (top) level
- * to the in-core extent allocation scheme. These structs are allocated
- * in a contiguous block, creating an indirection array where each entry
- * (irec) contains a pointer to a buffer of in-core extent records which
- * it manages. Each extent buffer is 4k in size, since 4k is the system
- * page size on Linux i386 and systems with larger page sizes don't seem
- * to gain much, if anything, by using their native page size as the
- * extent buffer size. Also, using 4k extent buffers everywhere provides
- * a consistent interface for CXFS across different platforms.
- *
- * There is currently no limit on the number of irec's (extent lists)
- * allowed, so heavily fragmented files may require an indirection array
- * which spans multiple system pages of memory. The number of extents
- * which would require this amount of contiguous memory is very large
- * and should not cause problems in the foreseeable future. However,
- * if the memory needed for the contiguous array ever becomes a problem,
- * it is possible that a third level of indirection may be required.
- */
-typedef struct xfs_ext_irec {
-	xfs_bmbt_rec_host_t *er_extbuf;	/* block of extent records */
-	xfs_extnum_t	er_extoff;	/* extent offset in file */
-	xfs_extnum_t	er_extcount;	/* number of extents in page/block */
-} xfs_ext_irec_t;
-
-/*
  * File incore extent information, present for each of data & attr forks.
  */
-#define	XFS_IEXT_BUFSZ		4096
-#define	XFS_LINEAR_EXTS		(XFS_IEXT_BUFSZ / (uint)sizeof(xfs_bmbt_rec_t))
-#define	XFS_INLINE_EXTS		2
-#define	XFS_INLINE_DATA		32
 typedef struct xfs_ifork {
 	int			if_bytes;	/* bytes in if_u1 */
 	int			if_real_bytes;	/* bytes allocated in if_u1 */
 	struct xfs_btree_block	*if_broot;	/* file's incore btree root */
 	short			if_broot_bytes;	/* bytes allocated for root */
 	unsigned char		if_flags;	/* per-fork flags */
+	int			if_height;	/* height of the extent tree */
 	union {
-		xfs_bmbt_rec_host_t *if_extents;/* linear map file exts */
-		xfs_ext_irec_t	*if_ext_irec;	/* irec map file exts */
+		void		*if_root;	/* extent tree root */
 		char		*if_data;	/* inline file data */
 	} if_u1;
-	union {
-		xfs_bmbt_rec_host_t if_inline_ext[XFS_INLINE_EXTS];
-						/* very small file extents */
-		char		if_inline_data[XFS_INLINE_DATA];
-						/* very small file data */
-		xfs_dev_t	if_rdev;	/* dev number if special */
-		uuid_t		if_uuid;	/* mount point value */
-	} if_u2;
 } xfs_ifork_t;
 
 /*
···
 #define	XFS_IFINLINE	0x01	/* Inline data is read in */
 #define	XFS_IFEXTENTS	0x02	/* All extent pointers are read in */
 #define	XFS_IFBROOT	0x04	/* i_broot points to the bmap b-tree root */
-#define	XFS_IFEXTIREC	0x08	/* Indirection array of extent blocks */
 
 /*
  * Fork handling.
···
 				  int);
 void		xfs_init_local_fork(struct xfs_inode *, int, const void *, int);
 
-struct xfs_bmbt_rec_host *
-		xfs_iext_get_ext(struct xfs_ifork *, xfs_extnum_t);
-xfs_extnum_t	xfs_iext_count(struct xfs_ifork *);
-void		xfs_iext_insert(struct xfs_inode *, xfs_extnum_t, xfs_extnum_t,
-				struct xfs_bmbt_irec *, int);
-void		xfs_iext_add(struct xfs_ifork *, xfs_extnum_t, int);
-void		xfs_iext_add_indirect_multi(struct xfs_ifork *, int,
-					    xfs_extnum_t, int);
-void		xfs_iext_remove(struct xfs_inode *, xfs_extnum_t, int, int);
-void		xfs_iext_remove_inline(struct xfs_ifork *, xfs_extnum_t, int);
-void		xfs_iext_remove_direct(struct xfs_ifork *, xfs_extnum_t, int);
-void		xfs_iext_remove_indirect(struct xfs_ifork *, xfs_extnum_t, int);
-void		xfs_iext_realloc_direct(struct xfs_ifork *, int);
-void		xfs_iext_direct_to_inline(struct xfs_ifork *, xfs_extnum_t);
-void		xfs_iext_inline_to_direct(struct xfs_ifork *, int);
+xfs_extnum_t	xfs_iext_count(struct xfs_ifork *ifp);
+void		xfs_iext_insert(struct xfs_inode *, struct xfs_iext_cursor *cur,
+			struct xfs_bmbt_irec *, int);
+void		xfs_iext_remove(struct xfs_inode *, struct xfs_iext_cursor *,
+			int);
 void		xfs_iext_destroy(struct xfs_ifork *);
-struct xfs_bmbt_rec_host *
-		xfs_iext_bno_to_ext(struct xfs_ifork *, xfs_fileoff_t, int *);
-struct xfs_ext_irec *
-		xfs_iext_bno_to_irec(struct xfs_ifork *, xfs_fileoff_t, int *);
-struct xfs_ext_irec *
-		xfs_iext_idx_to_irec(struct xfs_ifork *, xfs_extnum_t *, int *,
-				     int);
-void		xfs_iext_irec_init(struct xfs_ifork *);
-struct xfs_ext_irec *
-		xfs_iext_irec_new(struct xfs_ifork *, int);
-void		xfs_iext_irec_remove(struct xfs_ifork *, int);
-void		xfs_iext_irec_compact(struct xfs_ifork *);
-void		xfs_iext_irec_compact_pages(struct xfs_ifork *);
-void		xfs_iext_irec_compact_full(struct xfs_ifork *);
-void		xfs_iext_irec_update_extoffs(struct xfs_ifork *, int, int);
 
 bool		xfs_iext_lookup_extent(struct xfs_inode *ip,
 			struct xfs_ifork *ifp, xfs_fileoff_t bno,
-			xfs_extnum_t *idxp, struct xfs_bmbt_irec *gotp);
-bool		xfs_iext_get_extent(struct xfs_ifork *ifp, xfs_extnum_t idx,
+			struct xfs_iext_cursor *cur,
 			struct xfs_bmbt_irec *gotp);
-void		xfs_iext_update_extent(struct xfs_ifork *ifp, xfs_extnum_t idx,
+bool		xfs_iext_lookup_extent_before(struct xfs_inode *ip,
+			struct xfs_ifork *ifp, xfs_fileoff_t *end,
+			struct xfs_iext_cursor *cur,
 			struct xfs_bmbt_irec *gotp);
+bool		xfs_iext_get_extent(struct xfs_ifork *ifp,
+			struct xfs_iext_cursor *cur,
+			struct xfs_bmbt_irec *gotp);
+void		xfs_iext_update_extent(struct xfs_inode *ip, int state,
+			struct xfs_iext_cursor *cur,
+			struct xfs_bmbt_irec *gotp);
+
+void		xfs_iext_first(struct xfs_ifork *, struct xfs_iext_cursor *);
+void		xfs_iext_last(struct xfs_ifork *, struct xfs_iext_cursor *);
+void		xfs_iext_next(struct xfs_ifork *, struct xfs_iext_cursor *);
+void		xfs_iext_prev(struct xfs_ifork *, struct xfs_iext_cursor *);
+
+static inline bool xfs_iext_next_extent(struct xfs_ifork *ifp,
+		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
+{
+	xfs_iext_next(ifp, cur);
+	return xfs_iext_get_extent(ifp, cur, gotp);
+}
+
+static inline bool xfs_iext_prev_extent(struct xfs_ifork *ifp,
+		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
+{
+	xfs_iext_prev(ifp, cur);
+	return xfs_iext_get_extent(ifp, cur, gotp);
+}
+
+/*
+ * Return the extent after cur in gotp without updating the cursor.
+ */
+static inline bool xfs_iext_peek_next_extent(struct xfs_ifork *ifp,
+		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
+{
+	struct xfs_iext_cursor ncur = *cur;
+
+	xfs_iext_next(ifp, &ncur);
+	return xfs_iext_get_extent(ifp, &ncur, gotp);
+}
+
+/*
+ * Return the extent before cur in gotp without updating the cursor.
+ */
+static inline bool xfs_iext_peek_prev_extent(struct xfs_ifork *ifp,
+		struct xfs_iext_cursor *cur, struct xfs_bmbt_irec *gotp)
+{
+	struct xfs_iext_cursor ncur = *cur;
+
+	xfs_iext_prev(ifp, &ncur);
+	return xfs_iext_get_extent(ifp, &ncur, gotp);
+}
+
+#define for_each_xfs_iext(ifp, ext, got)		\
+	for (xfs_iext_first((ifp), (ext));		\
+	     xfs_iext_get_extent((ifp), (ext), (got));	\
+	     xfs_iext_next((ifp), (ext)))
 
 extern struct kmem_zone	*xfs_ifork_zone;
 

fs/xfs/libxfs/xfs_log_format.h

···
  * (if any) is indicated in the ilf_dsize field.  Changes to this structure
  * must be added on to the end.
  */
-typedef struct xfs_inode_log_format {
+struct xfs_inode_log_format {
 	uint16_t		ilf_type;	/* inode log item type */
 	uint16_t		ilf_size;	/* size of this item */
 	uint32_t		ilf_fields;	/* flags for fields logged */
···
 	uint64_t		ilf_ino;	/* inode number */
 	union {
 		uint32_t	ilfu_rdev;	/* rdev value for dev inode*/
-		uuid_t		ilfu_uuid;	/* mount point value */
+		u8		__pad[16];	/* unused */
 	} ilf_u;
 	int64_t			ilf_blkno;	/* blkno of inode buffer */
 	int32_t			ilf_len;	/* len of inode buffer */
 	int32_t			ilf_boffset;	/* off of inode in buffer */
-} xfs_inode_log_format_t;
+};
 
 /*
  * Old 32 bit systems will log in this format without the 64 bit
···
 	uint64_t		ilf_ino;	/* inode number */
 	union {
 		uint32_t	ilfu_rdev;	/* rdev value for dev inode*/
-		uuid_t		ilfu_uuid;	/* mount point value */
+		u8		__pad[16];	/* unused */
 	} ilf_u;
 	int64_t			ilf_blkno;	/* blkno of inode buffer */
 	int32_t			ilf_len;	/* len of inode buffer */
···
 #define	XFS_ILOG_DEXT	0x004	/* log i_df.if_extents */
 #define	XFS_ILOG_DBROOT	0x008	/* log i_df.i_broot */
 #define	XFS_ILOG_DEV	0x010	/* log the dev field */
-#define	XFS_ILOG_UUID	0x020	/* log the uuid field */
+#define	XFS_ILOG_UUID	0x020	/* added long ago, but never used */
 #define	XFS_ILOG_ADATA	0x040	/* log i_af.if_data */
 #define	XFS_ILOG_AEXT	0x080	/* log i_af.if_extents */
 #define	XFS_ILOG_ABROOT	0x100	/* log i_af.i_broot */
···
 
 #define	XFS_ILOG_NONCORE	(XFS_ILOG_DDATA | XFS_ILOG_DEXT | \
 				 XFS_ILOG_DBROOT | XFS_ILOG_DEV | \
-				 XFS_ILOG_UUID | XFS_ILOG_ADATA | \
-				 XFS_ILOG_AEXT | XFS_ILOG_ABROOT | \
-				 XFS_ILOG_DOWNER | XFS_ILOG_AOWNER)
+				 XFS_ILOG_ADATA | XFS_ILOG_AEXT | \
+				 XFS_ILOG_ABROOT | XFS_ILOG_DOWNER | \
+				 XFS_ILOG_AOWNER)
 
 #define	XFS_ILOG_DFORK		(XFS_ILOG_DDATA | XFS_ILOG_DEXT | \
 				 XFS_ILOG_DBROOT)
···
 
 #define	XFS_ILOG_ALL		(XFS_ILOG_CORE | XFS_ILOG_DDATA | \
 				 XFS_ILOG_DEXT | XFS_ILOG_DBROOT | \
-				 XFS_ILOG_DEV | XFS_ILOG_UUID | \
-				 XFS_ILOG_ADATA | XFS_ILOG_AEXT | \
-				 XFS_ILOG_ABROOT | XFS_ILOG_TIMESTAMP | \
-				 XFS_ILOG_DOWNER | XFS_ILOG_AOWNER)
+				 XFS_ILOG_DEV | XFS_ILOG_ADATA | \
+				 XFS_ILOG_AEXT | XFS_ILOG_ABROOT | \
+				 XFS_ILOG_TIMESTAMP | XFS_ILOG_DOWNER | \
+				 XFS_ILOG_AOWNER)
 
 static inline int xfs_ilog_fbroot(int w)
 {

fs/xfs/libxfs/xfs_refcount.c

···
 #include "xfs_bmap.h"
 #include "xfs_refcount_btree.h"
 #include "xfs_alloc.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
 #include "xfs_cksum.h"

fs/xfs/libxfs/xfs_rmap.c

···
 #include "xfs_rmap_btree.h"
 #include "xfs_trans_space.h"
 #include "xfs_trace.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_extent_busy.h"
 #include "xfs_bmap.h"

fs/xfs/libxfs/xfs_rtbitmap.c

···
 		/*
 		 * Compute a mask of relevant bits.
 		 */
-		bit = 0;
 		mask = ((xfs_rtword_t)1 << lastbit) - 1;
 		/*
 		 * Set/clear the active bits.
···
 	keys[0].ar_blockcount = keys[1].ar_blockcount = 0;
 
 	return xfs_rtalloc_query_range(tp, &keys[0], &keys[1], fn, priv);
+}
+
+/*
+ * Verify that an realtime block number pointer doesn't point off the
+ * end of the realtime device.
+ */
+bool
+xfs_verify_rtbno(
+	struct xfs_mount	*mp,
+	xfs_rtblock_t		rtbno)
+{
+	return rtbno < mp->m_sb.sb_rblocks;
 }

fs/xfs/libxfs/xfs_types.h

···
 typedef int64_t		xfs_sfiloff_t;	/* signed block number in a file */
 
 /*
+ * New verifiers will return the instruction address of the failing check.
+ * NULL means everything is ok.
+ */
+typedef void *		xfs_failaddr_t;
+
+/*
  * Null values for the types.
  */
 #define	NULLFSBLOCK	((xfs_fsblock_t)-1)
···
 #define	XFS_NBWORD	(1 << XFS_NBWORDLOG)
 #define	XFS_WORDMASK	((1 << XFS_WORDLOG) - 1)
 
+struct xfs_iext_cursor {
+	struct xfs_iext_leaf	*leaf;
+	int			pos;
+};
+
+typedef enum {
+	XFS_EXT_NORM, XFS_EXT_UNWRITTEN,
+} xfs_exntst_t;
+
+typedef struct xfs_bmbt_irec
+{
+	xfs_fileoff_t	br_startoff;	/* starting file offset */
+	xfs_fsblock_t	br_startblock;	/* starting block number */
+	xfs_filblks_t	br_blockcount;	/* number of blocks */
+	xfs_exntst_t	br_state;	/* extent state */
+} xfs_bmbt_irec_t;
 
 #endif	/* __XFS_TYPES_H__ */

fs/xfs/scrub/agheader.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_alloc.h"
+#include "xfs_ialloc.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+
+/*
+ * Set up scrub to check all the static metadata in each AG.
+ * This means the SB, AGF, AGI, and AGFL headers.
+ */
+int
+xfs_scrub_setup_ag_header(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	struct xfs_mount		*mp = sc->mp;
+
+	if (sc->sm->sm_agno >= mp->m_sb.sb_agcount ||
+	    sc->sm->sm_ino || sc->sm->sm_gen)
+		return -EINVAL;
+	return xfs_scrub_setup_fs(sc, ip);
+}
+
+/* Walk all the blocks in the AGFL. */
+int
+xfs_scrub_walk_agfl(
+	struct xfs_scrub_context	*sc,
+	int				(*fn)(struct xfs_scrub_context *,
+					      xfs_agblock_t bno, void *),
+	void				*priv)
+{
+	struct xfs_agf			*agf;
+	__be32				*agfl_bno;
+	struct xfs_mount		*mp = sc->mp;
+	unsigned int			flfirst;
+	unsigned int			fllast;
+	int				i;
+	int				error;
+
+	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
+	agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, sc->sa.agfl_bp);
+	flfirst = be32_to_cpu(agf->agf_flfirst);
+	fllast = be32_to_cpu(agf->agf_fllast);
+
+	/* Nothing to walk in an empty AGFL. */
+	if (agf->agf_flcount == cpu_to_be32(0))
+		return 0;
+
+	/* first to last is a consecutive list. */
+	if (fllast >= flfirst) {
+		for (i = flfirst; i <= fllast; i++) {
+			error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
+			if (error)
+				return error;
+			if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+				return error;
+		}
+
+		return 0;
+	}
+
+	/* first to the end */
+	for (i = flfirst; i < XFS_AGFL_SIZE(mp); i++) {
+		error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
+		if (error)
+			return error;
+		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+			return error;
+	}
+
+	/* the start to last. */
+	for (i = 0; i <= fllast; i++) {
+		error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
+		if (error)
+			return error;
+		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+			return error;
+	}
+
+	return 0;
+}
+
+/* Superblock */
+
+/*
+ * Scrub the filesystem superblock.
+ *
+ * Note: We do /not/ attempt to check AG 0's superblock.  Mount is
+ * responsible for validating all the geometry information in sb 0, so
+ * if the filesystem is capable of initiating online scrub, then clearly
+ * sb 0 is ok and we can use its information to check everything else.
+ */
+int
+xfs_scrub_superblock(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_buf			*bp;
+	struct xfs_dsb			*sb;
+	xfs_agnumber_t			agno;
+	uint32_t			v2_ok;
+	__be32				features_mask;
+	int				error;
+	__be16				vernum_mask;
+
+	agno = sc->sm->sm_agno;
+	if (agno == 0)
+		return 0;
+
+	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
+		  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
+		  XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops);
+	if (!xfs_scrub_process_error(sc, agno, XFS_SB_BLOCK(mp), &error))
+		return error;
+
+	sb = XFS_BUF_TO_SBP(bp);
+
+	/*
+	 * Verify the geometries match.  Fields that are permanently
+	 * set by mkfs are checked; fields that can be updated later
+	 * (and are not propagated to backup superblocks) are preen
+	 * checked.
+	 */
+	if (sb->sb_blocksize != cpu_to_be32(mp->m_sb.sb_blocksize))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_dblocks != cpu_to_be64(mp->m_sb.sb_dblocks))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_rblocks != cpu_to_be64(mp->m_sb.sb_rblocks))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_rextents != cpu_to_be64(mp->m_sb.sb_rextents))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (!uuid_equal(&sb->sb_uuid, &mp->m_sb.sb_uuid))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_logstart != cpu_to_be64(mp->m_sb.sb_logstart))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_rootino != cpu_to_be64(mp->m_sb.sb_rootino))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_rbmino != cpu_to_be64(mp->m_sb.sb_rbmino))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_rsumino != cpu_to_be64(mp->m_sb.sb_rsumino))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_rextsize != cpu_to_be32(mp->m_sb.sb_rextsize))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_agblocks != cpu_to_be32(mp->m_sb.sb_agblocks))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_agcount != cpu_to_be32(mp->m_sb.sb_agcount))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_rbmblocks != cpu_to_be32(mp->m_sb.sb_rbmblocks))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_logblocks != cpu_to_be32(mp->m_sb.sb_logblocks))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	/* Check sb_versionnum bits that are set at mkfs time. */
+	vernum_mask = cpu_to_be16(~XFS_SB_VERSION_OKBITS |
+				  XFS_SB_VERSION_NUMBITS |
+				  XFS_SB_VERSION_ALIGNBIT |
+				  XFS_SB_VERSION_DALIGNBIT |
+				  XFS_SB_VERSION_SHAREDBIT |
+				  XFS_SB_VERSION_LOGV2BIT |
+				  XFS_SB_VERSION_SECTORBIT |
+				  XFS_SB_VERSION_EXTFLGBIT |
+				  XFS_SB_VERSION_DIRV2BIT);
+	if ((sb->sb_versionnum & vernum_mask) !=
+	    (cpu_to_be16(mp->m_sb.sb_versionnum) & vernum_mask))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	/* Check sb_versionnum bits that can be set after mkfs time. */
+	vernum_mask = cpu_to_be16(XFS_SB_VERSION_ATTRBIT |
+				  XFS_SB_VERSION_NLINKBIT |
+				  XFS_SB_VERSION_QUOTABIT);
+	if ((sb->sb_versionnum & vernum_mask) !=
+	    (cpu_to_be16(mp->m_sb.sb_versionnum) & vernum_mask))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_sectsize != cpu_to_be16(mp->m_sb.sb_sectsize))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_inodesize != cpu_to_be16(mp->m_sb.sb_inodesize))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_inopblock != cpu_to_be16(mp->m_sb.sb_inopblock))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (memcmp(sb->sb_fname, mp->m_sb.sb_fname, sizeof(sb->sb_fname)))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_blocklog != mp->m_sb.sb_blocklog)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_sectlog != mp->m_sb.sb_sectlog)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_inodelog != mp->m_sb.sb_inodelog)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_inopblog != mp->m_sb.sb_inopblog)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_agblklog != mp->m_sb.sb_agblklog)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_rextslog != mp->m_sb.sb_rextslog)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_imax_pct != mp->m_sb.sb_imax_pct)
+		xfs_scrub_block_set_preen(sc, bp);
+
+	/*
+	 * Skip the summary counters since we track them in memory anyway.
+	 * sb_icount, sb_ifree, sb_fdblocks, sb_frexents
+	 */
+
+	if (sb->sb_uquotino != cpu_to_be64(mp->m_sb.sb_uquotino))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_gquotino != cpu_to_be64(mp->m_sb.sb_gquotino))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	/*
+	 * Skip the quota flags since repair will force quotacheck.
+	 * sb_qflags
+	 */
+
+	if (sb->sb_flags != mp->m_sb.sb_flags)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_shared_vn != mp->m_sb.sb_shared_vn)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_inoalignmt != cpu_to_be32(mp->m_sb.sb_inoalignmt))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_unit != cpu_to_be32(mp->m_sb.sb_unit))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_width != cpu_to_be32(mp->m_sb.sb_width))
+		xfs_scrub_block_set_preen(sc, bp);
+
+	if (sb->sb_dirblklog != mp->m_sb.sb_dirblklog)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_logsectlog != mp->m_sb.sb_logsectlog)
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_logsectsize != cpu_to_be16(mp->m_sb.sb_logsectsize))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (sb->sb_logsunit != cpu_to_be32(mp->m_sb.sb_logsunit))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	/* Do we see any invalid bits in sb_features2? */
+	if (!xfs_sb_version_hasmorebits(&mp->m_sb)) {
+		if (sb->sb_features2 != 0)
+			xfs_scrub_block_set_corrupt(sc, bp);
+	} else {
+		v2_ok = XFS_SB_VERSION2_OKBITS;
+		if (XFS_SB_VERSION_NUM(&mp->m_sb) >= XFS_SB_VERSION_5)
+			v2_ok |= XFS_SB_VERSION2_CRCBIT;
+
+		if (!!(sb->sb_features2 & cpu_to_be32(~v2_ok)))
+			xfs_scrub_block_set_corrupt(sc, bp);
+
+		if (sb->sb_features2 != sb->sb_bad_features2)
+			xfs_scrub_block_set_preen(sc, bp);
+	}
+
+	/* Check sb_features2 flags that are set at mkfs time. */
+	features_mask = cpu_to_be32(XFS_SB_VERSION2_LAZYSBCOUNTBIT |
+				    XFS_SB_VERSION2_PROJID32BIT |
+				    XFS_SB_VERSION2_CRCBIT |
+				    XFS_SB_VERSION2_FTYPE);
+	if ((sb->sb_features2 & features_mask) !=
+	    (cpu_to_be32(mp->m_sb.sb_features2) & features_mask))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	/* Check sb_features2 flags that can be set after mkfs time. */
+	features_mask = cpu_to_be32(XFS_SB_VERSION2_ATTR2BIT);
+	if ((sb->sb_features2 & features_mask) !=
+	    (cpu_to_be32(mp->m_sb.sb_features2) & features_mask))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
+		/* all v5 fields must be zero */
+		if (memchr_inv(&sb->sb_features_compat, 0,
+				sizeof(struct xfs_dsb) -
+				offsetof(struct xfs_dsb, sb_features_compat)))
+			xfs_scrub_block_set_corrupt(sc, bp);
+	} else {
+		/* Check compat flags; all are set at mkfs time. */
+		features_mask = cpu_to_be32(XFS_SB_FEAT_COMPAT_UNKNOWN);
+		if ((sb->sb_features_compat & features_mask) !=
+		    (cpu_to_be32(mp->m_sb.sb_features_compat) & features_mask))
+			xfs_scrub_block_set_corrupt(sc, bp);
+
+		/* Check ro compat flags; all are set at mkfs time. */
+		features_mask = cpu_to_be32(XFS_SB_FEAT_RO_COMPAT_UNKNOWN |
+					    XFS_SB_FEAT_RO_COMPAT_FINOBT |
+					    XFS_SB_FEAT_RO_COMPAT_RMAPBT |
+					    XFS_SB_FEAT_RO_COMPAT_REFLINK);
+		if ((sb->sb_features_ro_compat & features_mask) !=
+		    (cpu_to_be32(mp->m_sb.sb_features_ro_compat) &
+		     features_mask))
+			xfs_scrub_block_set_corrupt(sc, bp);
+
+		/* Check incompat flags; all are set at mkfs time. */
+		features_mask = cpu_to_be32(XFS_SB_FEAT_INCOMPAT_UNKNOWN |
+					    XFS_SB_FEAT_INCOMPAT_FTYPE |
+					    XFS_SB_FEAT_INCOMPAT_SPINODES |
+					    XFS_SB_FEAT_INCOMPAT_META_UUID);
+		if ((sb->sb_features_incompat & features_mask) !=
+		    (cpu_to_be32(mp->m_sb.sb_features_incompat) &
+		     features_mask))
+			xfs_scrub_block_set_corrupt(sc, bp);
+
+		/* Check log incompat flags; all are set at mkfs time. */
+		features_mask = cpu_to_be32(XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN);
+		if ((sb->sb_features_log_incompat & features_mask) !=
+		    (cpu_to_be32(mp->m_sb.sb_features_log_incompat) &
+		     features_mask))
+			xfs_scrub_block_set_corrupt(sc, bp);
+
+		/* Don't care about sb_crc */
+
+		if (sb->sb_spino_align != cpu_to_be32(mp->m_sb.sb_spino_align))
+			xfs_scrub_block_set_corrupt(sc, bp);
+
+		if (sb->sb_pquotino != cpu_to_be64(mp->m_sb.sb_pquotino))
+			xfs_scrub_block_set_preen(sc, bp);
+
+		/* Don't care about sb_lsn */
+	}
+
+	if (xfs_sb_version_hasmetauuid(&mp->m_sb)) {
+		/* The metadata UUID must be the same for all supers */
+		if (!uuid_equal(&sb->sb_meta_uuid, &mp->m_sb.sb_meta_uuid))
+			xfs_scrub_block_set_corrupt(sc, bp);
+	}
+
+	/* Everything else must be zero. */
+	if (memchr_inv(sb + 1, 0,
+			BBTOB(bp->b_length) - sizeof(struct xfs_dsb)))
+		xfs_scrub_block_set_corrupt(sc, bp);
+
+	return error;
+}
+
+/* AGF */
+
+/* Scrub the AGF. */
+int
+xfs_scrub_agf(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_agf			*agf;
+	xfs_agnumber_t			agno;
+	xfs_agblock_t			agbno;
+	xfs_agblock_t			eoag;
+	xfs_agblock_t			agfl_first;
+	xfs_agblock_t			agfl_last;
+	xfs_agblock_t			agfl_count;
+	xfs_agblock_t			fl_count;
+	int				level;
+	int				error = 0;
+
+	agno = sc->sa.agno = sc->sm->sm_agno;
+	error = xfs_scrub_ag_read_headers(sc, agno, &sc->sa.agi_bp,
+			&sc->sa.agf_bp, &sc->sa.agfl_bp);
+	if (!xfs_scrub_process_error(sc, agno, XFS_AGF_BLOCK(sc->mp), &error))
+		goto out;
+
+	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
+
+	/* Check the AG length */
+	eoag = be32_to_cpu(agf->agf_length);
+	if (eoag != xfs_ag_block_count(mp, agno))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+
+	/* Check the AGF btree roots and levels */
+	agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_BNO]);
+	if (!xfs_verify_agbno(mp, agno, agbno))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+
+	agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_CNT]);
+	if (!xfs_verify_agbno(mp, agno, agbno))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+
+	level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
+	if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+
+	level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
+	if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+		agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_RMAP]);
+		if (!xfs_verify_agbno(mp, agno, agbno))
+			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+
+		level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]);
+		if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
+			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+	}
+
+	if (xfs_sb_version_hasreflink(&mp->m_sb)) {
+		agbno = be32_to_cpu(agf->agf_refcount_root);
+		if (!xfs_verify_agbno(mp, agno, agbno))
+			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+
+		level = be32_to_cpu(agf->agf_refcount_level);
+		if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
+			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+	}
+
+	/* Check the AGFL counters */
+	agfl_first = be32_to_cpu(agf->agf_flfirst);
+	agfl_last = be32_to_cpu(agf->agf_fllast);
+	agfl_count = be32_to_cpu(agf->agf_flcount);
+	if (agfl_last > agfl_first)
+		fl_count = agfl_last - agfl_first + 1;
+	else
+		fl_count = XFS_AGFL_SIZE(mp) - agfl_first + agfl_last + 1;
+	if (agfl_count != 0 && fl_count != agfl_count)
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+
+out:
+	return error;
+}
+
+/* AGFL */
+
+struct xfs_scrub_agfl_info {
+	unsigned int			sz_entries;
+	unsigned int			nr_entries;
+	xfs_agblock_t			*entries;
+};
+
+/* Scrub an AGFL block. */
+STATIC int
+xfs_scrub_agfl_block(
+	struct xfs_scrub_context	*sc,
+	xfs_agblock_t			agbno,
+	void				*priv)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_scrub_agfl_info	*sai = priv;
+	xfs_agnumber_t			agno = sc->sa.agno;
+
+	if (xfs_verify_agbno(mp, agno, agbno) &&
+	    sai->nr_entries < sai->sz_entries)
+		sai->entries[sai->nr_entries++] = agbno;
+	else
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agfl_bp);
+
+	return 0;
+}
+
+static int
+xfs_scrub_agblock_cmp(
+	const void		*pa,
+	const void		*pb)
+{
+	const xfs_agblock_t	*a = pa;
+	const xfs_agblock_t	*b = pb;
+
+	return (int)*a - (int)*b;
+}
+
+/* Scrub the AGFL. */
+int
+xfs_scrub_agfl(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_scrub_agfl_info	sai = { 0 };
+	struct xfs_agf			*agf;
+	xfs_agnumber_t			agno;
+	unsigned int			agflcount;
+	unsigned int			i;
+	int				error;
+
+	agno = sc->sa.agno = sc->sm->sm_agno;
+	error = xfs_scrub_ag_read_headers(sc, agno, &sc->sa.agi_bp,
+			&sc->sa.agf_bp, &sc->sa.agfl_bp);
+	if (!xfs_scrub_process_error(sc, agno, XFS_AGFL_BLOCK(sc->mp), &error))
+		goto out;
+	if (!sc->sa.agf_bp)
+		return -EFSCORRUPTED;
+
+	/* Allocate buffer to ensure uniqueness of AGFL entries. */
+	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
+	agflcount = be32_to_cpu(agf->agf_flcount);
+	if (agflcount > XFS_AGFL_SIZE(sc->mp)) {
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+		goto out;
+	}
+	sai.sz_entries = agflcount;
+	sai.entries = kmem_zalloc(sizeof(xfs_agblock_t) * agflcount, KM_NOFS);
+	if (!sai.entries) {
+		error = -ENOMEM;
+		goto out;
+	}
+
+	/* Check the blocks in the AGFL. */
+	error = xfs_scrub_walk_agfl(sc, xfs_scrub_agfl_block, &sai);
+	if (error)
+		goto out_free;
+
+	if (agflcount != sai.nr_entries) {
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+		goto out_free;
+	}
+
+	/* Sort entries, check for duplicates. */
+	sort(sai.entries, sai.nr_entries, sizeof(sai.entries[0]),
+			xfs_scrub_agblock_cmp, NULL);
+	for (i = 1; i < sai.nr_entries; i++) {
+		if (sai.entries[i] == sai.entries[i - 1]) {
+			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
+			break;
+		}
+	}
+
+out_free:
+	kmem_free(sai.entries);
+out:
+	return error;
+}
+
+/* AGI */
+
+/* Scrub the AGI. */
+int
+xfs_scrub_agi(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_agi			*agi;
+	xfs_agnumber_t			agno;
+	xfs_agblock_t			agbno;
+	xfs_agblock_t			eoag;
+	xfs_agino_t			agino;
+	xfs_agino_t			first_agino;
+	xfs_agino_t			last_agino;
+	xfs_agino_t			icount;
+	int				i;
+	int				level;
+	int				error = 0;
+
+	agno = sc->sa.agno = sc->sm->sm_agno;
+	error = xfs_scrub_ag_read_headers(sc, agno, &sc->sa.agi_bp,
+			&sc->sa.agf_bp, &sc->sa.agfl_bp);
+	if (!xfs_scrub_process_error(sc, agno, XFS_AGI_BLOCK(sc->mp), &error))
+		goto out;
+
+	agi = XFS_BUF_TO_AGI(sc->sa.agi_bp);
+
+	/* Check the AG length */
+	eoag = be32_to_cpu(agi->agi_length);
+	if (eoag != xfs_ag_block_count(mp, agno))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+
+	/* Check btree roots and levels */
+	agbno = be32_to_cpu(agi->agi_root);
+	if (!xfs_verify_agbno(mp, agno, agbno))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+
+	level = be32_to_cpu(agi->agi_level);
+	if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+
+	if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
+		agbno = be32_to_cpu(agi->agi_free_root);
+		if (!xfs_verify_agbno(mp, agno, agbno))
+			xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+
+		level = be32_to_cpu(agi->agi_free_level);
+		if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
+			xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+	}
+
+	/* Check inode counters */
+	xfs_ialloc_agino_range(mp, agno, &first_agino, &last_agino);
+	icount = be32_to_cpu(agi->agi_count);
+	if (icount > last_agino - first_agino + 1 ||
+	    icount < be32_to_cpu(agi->agi_freecount))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+
+	/* Check inode pointers */
+	agino = be32_to_cpu(agi->agi_newino);
+	if (agino != NULLAGINO && !xfs_verify_agino(mp, agno, agino))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+
+	agino = be32_to_cpu(agi->agi_dirino);
+	if (agino != NULLAGINO && !xfs_verify_agino(mp, agno, agino))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+
+	/* Check unlinked inode buckets */
+	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
+		agino = be32_to_cpu(agi->agi_unlinked[i]);
+		if (agino == NULLAGINO)
+			continue;
+		if (!xfs_verify_agino(mp, agno, agino))
+			xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+	}
+
+	if (agi->agi_pad32 != cpu_to_be32(0))
+		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
+
+out:
+	return error;
+}

fs/xfs/scrub/alloc.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_alloc.h"
+#include "xfs_rmap.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+
+/*
+ * Set us up to scrub free space btrees.
+ */
+int
+xfs_scrub_setup_ag_allocbt(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	return xfs_scrub_setup_ag_btree(sc, ip, false);
+}
+
+/* Free space btree scrubber. */
+
+/* Scrub a bnobt/cntbt record. */
+STATIC int
+xfs_scrub_allocbt_rec(
+	struct xfs_scrub_btree		*bs,
+	union xfs_btree_rec		*rec)
+{
+	struct xfs_mount		*mp = bs->cur->bc_mp;
+	xfs_agnumber_t			agno = bs->cur->bc_private.a.agno;
+	xfs_agblock_t			bno;
+	xfs_extlen_t			len;
+	int				error = 0;
+
+	bno = be32_to_cpu(rec->alloc.ar_startblock);
+	len = be32_to_cpu(rec->alloc.ar_blockcount);
+
+	if (bno + len <= bno ||
+	    !xfs_verify_agbno(mp, agno, bno) ||
+	    !xfs_verify_agbno(mp, agno, bno + len - 1))
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	return error;
+}
+
+/* Scrub the freespace btrees for some AG. */
+STATIC int
+xfs_scrub_allocbt(
+	struct xfs_scrub_context	*sc,
+	xfs_btnum_t			which)
+{
+	struct xfs_owner_info		oinfo;
+	struct xfs_btree_cur		*cur;
+
+	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
+	cur = which == XFS_BTNUM_BNO ? sc->sa.bno_cur : sc->sa.cnt_cur;
+	return xfs_scrub_btree(sc, cur, xfs_scrub_allocbt_rec, &oinfo, NULL);
+}
+
+int
+xfs_scrub_bnobt(
+	struct xfs_scrub_context	*sc)
+{
+	return xfs_scrub_allocbt(sc, XFS_BTNUM_BNO);
+}
+
+int
+xfs_scrub_cntbt(
+	struct xfs_scrub_context	*sc)
+{
+	return xfs_scrub_allocbt(sc, XFS_BTNUM_CNT);
+}

fs/xfs/scrub/attr.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_attr.h"
+#include "xfs_attr_leaf.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/dabtree.h"
+#include "scrub/trace.h"
+
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+/* Set us up to scrub an inode's extended attributes. */
+int
+xfs_scrub_setup_xattr(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	size_t				sz;
+
+	/*
+	 * Allocate the buffer without the inode lock held.  We need enough
+	 * space to read every xattr value in the file or enough space to
+	 * hold three copies of the xattr free space bitmap.  (Not both at
+	 * the same time.)
+	 */
+	sz = max_t(size_t, XATTR_SIZE_MAX, 3 * sizeof(long) *
+			BITS_TO_LONGS(sc->mp->m_attr_geo->blksize));
+	sc->buf = kmem_zalloc_large(sz, KM_SLEEP);
+	if (!sc->buf)
+		return -ENOMEM;
+
+	return xfs_scrub_setup_inode_contents(sc, ip, 0);
+}
+
+/* Extended Attributes */
+
+struct xfs_scrub_xattr {
+	struct xfs_attr_list_context	context;
+	struct xfs_scrub_context	*sc;
+};
+
+/*
+ * Check that an extended attribute key can be looked up by hash.
+ *
+ * We use the XFS attribute list iterator (i.e. xfs_attr_list_int_ilocked)
+ * to call this function for every attribute key in an inode.  Once
+ * we're here, we load the attribute value to see if any errors happen,
+ * or if we get more or less data than we expected.
+ */
+static void
+xfs_scrub_xattr_listent(
+	struct xfs_attr_list_context	*context,
+	int				flags,
+	unsigned char			*name,
+	int				namelen,
+	int				valuelen)
+{
+	struct xfs_scrub_xattr		*sx;
+	struct xfs_da_args		args = { NULL };
+	int				error = 0;
+
+	sx = container_of(context, struct xfs_scrub_xattr, context);
+
+	if (flags & XFS_ATTR_INCOMPLETE) {
+		/* Incomplete attr key, just mark the inode for preening. */
+		xfs_scrub_ino_set_preen(sx->sc, context->dp->i_ino, NULL);
+		return;
+	}
+
+	args.flags = ATTR_KERNOTIME;
+	if (flags & XFS_ATTR_ROOT)
+		args.flags |= ATTR_ROOT;
+	else if (flags & XFS_ATTR_SECURE)
+		args.flags |= ATTR_SECURE;
+	args.geo = context->dp->i_mount->m_attr_geo;
+	args.whichfork = XFS_ATTR_FORK;
+	args.dp = context->dp;
+	args.name = name;
+	args.namelen = namelen;
+	args.hashval = xfs_da_hashname(args.name, args.namelen);
+	args.trans = context->tp;
+	args.value = sx->sc->buf;
+	args.valuelen = XATTR_SIZE_MAX;
+
+	error = xfs_attr_get_ilocked(context->dp, &args);
+	if (error == -EEXIST)
+		error = 0;
+	if (!xfs_scrub_fblock_process_error(sx->sc, XFS_ATTR_FORK, args.blkno,
+			&error))
+		goto fail_xref;
+	if (args.valuelen != valuelen)
+		xfs_scrub_fblock_set_corrupt(sx->sc, XFS_ATTR_FORK,
+					     args.blkno);
+
+fail_xref:
+	return;
+}
+
+/*
+ * Mark a range [start, start+len) in this map.  Returns true if the
+ * region was free, and false if there's a conflict or a problem.
+ *
+ * Within a char, the lowest bit of the char represents the byte with
+ * the smallest address
+ */
+STATIC bool
+xfs_scrub_xattr_set_map(
+	struct xfs_scrub_context	*sc,
+	unsigned long			*map,
+	unsigned int			start,
+	unsigned int			len)
+{
+	unsigned int			mapsize = sc->mp->m_attr_geo->blksize;
+	bool				ret = true;
+
+	if (start >= mapsize)
+		return false;
+	if (start + len > mapsize) {
+		len = mapsize - start;
+		ret = false;
+	}
+
+	if (find_next_bit(map, mapsize, start) < start + len)
+		ret = false;
+	bitmap_set(map, start, len);
+
+	return ret;
+}
+
+/*
+ * Check the leaf freemap from the usage bitmap.  Returns false if the
+ * attr freemap has problems or points to used space.
+ */
+STATIC bool
+xfs_scrub_xattr_check_freemap(
+	struct xfs_scrub_context	*sc,
+	unsigned long			*map,
+	struct xfs_attr3_icleaf_hdr	*leafhdr)
+{
+	unsigned long			*freemap;
+	unsigned long			*dstmap;
+	unsigned int			mapsize = sc->mp->m_attr_geo->blksize;
+	int				i;
+
+	/* Construct bitmap of freemap contents. */
+	freemap = (unsigned long *)sc->buf + BITS_TO_LONGS(mapsize);
+	bitmap_zero(freemap, mapsize);
+	for (i = 0; i < XFS_ATTR_LEAF_MAPSIZE; i++) {
+		if (!xfs_scrub_xattr_set_map(sc, freemap,
+				leafhdr->freemap[i].base,
+				leafhdr->freemap[i].size))
+			return false;
+	}
+
+	/* Look for bits that are set in freemap and are marked in use. */
+	dstmap = freemap + BITS_TO_LONGS(mapsize);
+	return bitmap_and(dstmap, freemap, map, mapsize) == 0;
+}
+
+/*
+ * Check this leaf entry's relations to everything else.
+ * Returns the number of bytes used for the name/value data.
+ */
+STATIC void
+xfs_scrub_xattr_entry(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	char				*buf_end,
+	struct xfs_attr_leafblock	*leaf,
+	struct xfs_attr3_icleaf_hdr	*leafhdr,
+	unsigned long			*usedmap,
+	struct xfs_attr_leaf_entry	*ent,
+	int				idx,
+	unsigned int			*usedbytes,
+	__u32				*last_hashval)
+{
+	struct xfs_mount		*mp = ds->state->mp;
+	char				*name_end;
+	struct xfs_attr_leaf_name_local	*lentry;
+	struct xfs_attr_leaf_name_remote *rentry;
+	unsigned int			nameidx;
+	unsigned int			namesize;
+
+	if (ent->pad2 != 0)
+		xfs_scrub_da_set_corrupt(ds, level);
+
+	/* Hash values in order? */
+	if (be32_to_cpu(ent->hashval) < *last_hashval)
+		xfs_scrub_da_set_corrupt(ds, level);
+	*last_hashval = be32_to_cpu(ent->hashval);
+
+	nameidx = be16_to_cpu(ent->nameidx);
+	if (nameidx < leafhdr->firstused ||
+	    nameidx >= mp->m_attr_geo->blksize) {
+		xfs_scrub_da_set_corrupt(ds, level);
+		return;
+	}
+
+	/* Check the name information. */
+	if (ent->flags & XFS_ATTR_LOCAL) {
+		lentry = xfs_attr3_leaf_name_local(leaf, idx);
+		namesize = xfs_attr_leaf_entsize_local(lentry->namelen,
+				be16_to_cpu(lentry->valuelen));
+		name_end = (char *)lentry + namesize;
+		if (lentry->namelen == 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+	} else {
+		rentry = xfs_attr3_leaf_name_remote(leaf, idx);
+		namesize = xfs_attr_leaf_entsize_remote(rentry->namelen);
+		name_end = (char *)rentry + namesize;
+		if (rentry->namelen == 0 || rentry->valueblk == 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+	}
+	if (name_end > buf_end)
+		xfs_scrub_da_set_corrupt(ds, level);
+
+	if (!xfs_scrub_xattr_set_map(ds->sc, usedmap, nameidx, namesize))
+		xfs_scrub_da_set_corrupt(ds, level);
+	if (!(ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+		*usedbytes += namesize;
+}
+
+/* Scrub an attribute leaf. */
+STATIC int
+xfs_scrub_xattr_block(
+	struct xfs_scrub_da_btree	*ds,
+	int				level)
+{
+	struct xfs_attr3_icleaf_hdr	leafhdr;
+	struct xfs_mount		*mp = ds->state->mp;
+	struct xfs_da_state_blk		*blk = &ds->state->path.blk[level];
+	struct xfs_buf			*bp = blk->bp;
+	xfs_dablk_t			*last_checked = ds->private;
+	struct xfs_attr_leafblock	*leaf = bp->b_addr;
+	struct xfs_attr_leaf_entry	*ent;
+	struct xfs_attr_leaf_entry	*entries;
+	unsigned long			*usedmap = ds->sc->buf;
+	char				*buf_end;
+	size_t				off;
+	__u32				last_hashval = 0;
+	unsigned int			usedbytes = 0;
+	unsigned int			hdrsize;
+	int				i;
+
+	if (*last_checked == blk->blkno)
+		return 0;
+	*last_checked = blk->blkno;
+	bitmap_zero(usedmap, mp->m_attr_geo->blksize);
+
+	/* Check all the padding. */
+	if (xfs_sb_version_hascrc(&ds->sc->mp->m_sb)) {
+		struct xfs_attr3_leafblock	*leaf = bp->b_addr;
+
+		if (leaf->hdr.pad1 != 0 || leaf->hdr.pad2 != 0 ||
+		    leaf->hdr.info.hdr.pad != 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+	} else {
+		if (leaf->hdr.pad1 != 0 || leaf->hdr.info.pad != 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+	}
+
+	/* Check the leaf header */
+	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &leafhdr, leaf);
+	hdrsize = xfs_attr3_leaf_hdr_size(leaf);
+
+	if (leafhdr.usedbytes > mp->m_attr_geo->blksize)
+		xfs_scrub_da_set_corrupt(ds, level);
+	if (leafhdr.firstused > mp->m_attr_geo->blksize)
+		xfs_scrub_da_set_corrupt(ds, level);
+	if (leafhdr.firstused < hdrsize)
+		xfs_scrub_da_set_corrupt(ds, level);
+	if (!xfs_scrub_xattr_set_map(ds->sc, usedmap, 0, hdrsize))
+		xfs_scrub_da_set_corrupt(ds, level);
+
+	if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	entries = xfs_attr3_leaf_entryp(leaf);
+	if ((char *)&entries[leafhdr.count] > (char *)leaf + leafhdr.firstused)
+		xfs_scrub_da_set_corrupt(ds, level);
+
+	buf_end = (char *)bp->b_addr + mp->m_attr_geo->blksize;
+	for (i = 0, ent = entries; i < leafhdr.count; ent++, i++) {
+		/* Mark the leaf entry itself. */
+		off = (char *)ent - (char *)leaf;
+		if (!xfs_scrub_xattr_set_map(ds->sc, usedmap, off,
+				sizeof(xfs_attr_leaf_entry_t))) {
+			xfs_scrub_da_set_corrupt(ds, level);
+			goto out;
+		}
+
+		/* Check the entry and nameval. */
+		xfs_scrub_xattr_entry(ds, level, buf_end, leaf, &leafhdr,
+				usedmap, ent, i, &usedbytes, &last_hashval);
+
+		if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+			goto out;
+	}
+
+	if (!xfs_scrub_xattr_check_freemap(ds->sc, usedmap, &leafhdr))
+		xfs_scrub_da_set_corrupt(ds, level);
+
+	if (leafhdr.usedbytes != usedbytes)
+		xfs_scrub_da_set_corrupt(ds, level);
+
+out:
+	return 0;
+}
+
+/* Scrub a attribute btree record. */
+STATIC int
+xfs_scrub_xattr_rec(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	void				*rec)
+{
+	struct xfs_mount		*mp = ds->state->mp;
+	struct xfs_attr_leaf_entry	*ent = rec;
+	struct xfs_da_state_blk		*blk;
+	struct xfs_attr_leaf_name_local	*lentry;
+	struct xfs_attr_leaf_name_remote	*rentry;
+	struct xfs_buf			*bp;
+	xfs_dahash_t			calc_hash;
+	xfs_dahash_t			hash;
+	int				nameidx;
+	int				hdrsize;
+	unsigned int			badflags;
+	int				error;
+
+	blk = &ds->state->path.blk[level];
+
+	/* Check the whole block, if necessary. */
+	error = xfs_scrub_xattr_block(ds, level);
+	if (error)
+		goto out;
+	if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/* Check the hash of the entry. */
+	error = xfs_scrub_da_btree_hash(ds, level, &ent->hashval);
+	if (error)
+		goto out;
+
+	/* Find the attr entry's location. */
+	bp = blk->bp;
+	hdrsize = xfs_attr3_leaf_hdr_size(bp->b_addr);
+	nameidx = be16_to_cpu(ent->nameidx);
+	if (nameidx < hdrsize || nameidx >= mp->m_attr_geo->blksize) {
+		xfs_scrub_da_set_corrupt(ds, level);
+		goto out;
+	}
+
+	/* Retrieve the entry and check it. */
+	hash = be32_to_cpu(ent->hashval);
+	badflags = ~(XFS_ATTR_LOCAL | XFS_ATTR_ROOT | XFS_ATTR_SECURE |
+			XFS_ATTR_INCOMPLETE);
+	if ((ent->flags & badflags) != 0)
+		xfs_scrub_da_set_corrupt(ds, level);
+	if (ent->flags & XFS_ATTR_LOCAL) {
+		lentry = (struct xfs_attr_leaf_name_local *)
+				(((char *)bp->b_addr) + nameidx);
+		if (lentry->namelen <= 0) {
+			xfs_scrub_da_set_corrupt(ds, level);
+			goto out;
+		}
+		calc_hash = xfs_da_hashname(lentry->nameval, lentry->namelen);
+	} else {
+		rentry = (struct xfs_attr_leaf_name_remote *)
+				(((char *)bp->b_addr) + nameidx);
+		if (rentry->namelen <= 0) {
+			xfs_scrub_da_set_corrupt(ds, level);
+			goto out;
+		}
+		calc_hash = xfs_da_hashname(rentry->name, rentry->namelen);
+	}
+	if (calc_hash != hash)
+		xfs_scrub_da_set_corrupt(ds, level);
+
+out:
+	return error;
+}
+
+/* Scrub the extended attribute metadata. */
+int
+xfs_scrub_xattr(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_scrub_xattr		sx;
+	struct attrlist_cursor_kern	cursor = { 0 };
+	xfs_dablk_t			last_checked = -1U;
+	int				error = 0;
+
+	if (!xfs_inode_hasattr(sc->ip))
+		return -ENOENT;
+
+	memset(&sx, 0, sizeof(sx));
+	/* Check attribute tree structure */
+	error = xfs_scrub_da_btree(sc, XFS_ATTR_FORK, xfs_scrub_xattr_rec,
+			&last_checked);
+	if (error)
+		goto out;
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/* Check that every attr key can also be looked up by hash. */
+	sx.context.dp = sc->ip;
+	sx.context.cursor = &cursor;
+	sx.context.resynch = 1;
+	sx.context.put_listent = xfs_scrub_xattr_listent;
+	sx.context.tp = sc->tp;
+	sx.context.flags = ATTR_INCOMPLETE;
+	sx.sc = sc;
+
+	/*
+	 * Look up every xattr in this file by name.
+	 *
+	 * Use the backend implementation of xfs_attr_list to call
+	 * xfs_scrub_xattr_listent on every attribute key in this inode.
+	 * In other words, we use the same iterator/callback mechanism
+	 * that listattr uses to scrub extended attributes, though in our
+	 * _listent function, we check the value of the attribute.
+	 *
+	 * The VFS only locks i_rwsem when modifying attrs, so keep all
+	 * three locks held because that's the only way to ensure we're
+	 * the only thread poking into the da btree.  We traverse the da
+	 * btree while holding a leaf buffer locked for the xattr name
+	 * iteration, which doesn't really follow the usual buffer
+	 * locking order.
+	 */
+	error = xfs_attr_list_int_ilocked(&sx.context);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_ATTR_FORK, 0, &error))
+		goto out;
+out:
+	return error;
+}

fs/xfs/scrub/bmap.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_inode_fork.h"
+#include "xfs_alloc.h"
+#include "xfs_rtalloc.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_rmap.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+
+/* Set us up with an inode's bmap. */
+int
+xfs_scrub_setup_inode_bmap(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	struct xfs_mount		*mp = sc->mp;
+	int				error;
+
+	error = xfs_scrub_get_inode(sc, ip);
+	if (error)
+		goto out;
+
+	sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
+	xfs_ilock(sc->ip, sc->ilock_flags);
+
+	/*
+	 * We don't want any ephemeral data fork updates sitting around
+	 * while we inspect block mappings, so wait for directio to finish
+	 * and flush dirty data if we have delalloc reservations.
+	 */
+	if (S_ISREG(VFS_I(sc->ip)->i_mode) &&
+	    sc->sm->sm_type == XFS_SCRUB_TYPE_BMBTD) {
+		inode_dio_wait(VFS_I(sc->ip));
+		error = filemap_write_and_wait(VFS_I(sc->ip)->i_mapping);
+		if (error)
+			goto out;
+	}
+
+	/* Got the inode, lock it and we're ready to go. */
+	error = xfs_scrub_trans_alloc(sc->sm, mp, &sc->tp);
+	if (error)
+		goto out;
+	sc->ilock_flags |= XFS_ILOCK_EXCL;
+	xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
+
+out:
+	/* scrub teardown will unlock and release the inode */
+	return error;
+}
+
+/*
+ * Inode fork block mapping (BMBT) scrubber.
+ * More complex than the others because we have to scrub
+ * all the extents regardless of whether or not the fork
+ * is in btree format.
+ */
+
+struct xfs_scrub_bmap_info {
+	struct xfs_scrub_context	*sc;
+	xfs_fileoff_t			lastoff;
+	bool				is_rt;
+	bool				is_shared;
+	int				whichfork;
+};
+
+/* Scrub a single extent record. */
+STATIC int
+xfs_scrub_bmap_extent(
+	struct xfs_inode		*ip,
+	struct xfs_btree_cur		*cur,
+	struct xfs_scrub_bmap_info	*info,
+	struct xfs_bmbt_irec		*irec)
+{
+	struct xfs_mount		*mp = info->sc->mp;
+	struct xfs_buf			*bp = NULL;
+	int				error = 0;
+
+	if (cur)
+		xfs_btree_get_block(cur, 0, &bp);
+
+	/*
+	 * Check for out-of-order extents.  This record could have come
+	 * from the incore list, for which there is no ordering check.
+	 */
+	if (irec->br_startoff < info->lastoff)
+		xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+
+	/* There should never be a "hole" extent in either extent list. */
+	if (irec->br_startblock == HOLESTARTBLOCK)
+		xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+
+	/*
+	 * Check for delalloc extents.  We never iterate the ones in the
+	 * in-core extent scan, and we should never see these in the bmbt.
+	 */
+	if (isnullstartblock(irec->br_startblock))
+		xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+
+	/* Make sure the extent points to a valid place. */
+	if (irec->br_startblock + irec->br_blockcount <= irec->br_startblock)
+		xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+	if (info->is_rt &&
+	    (!xfs_verify_rtbno(mp, irec->br_startblock) ||
+	     !xfs_verify_rtbno(mp, irec->br_startblock +
+				irec->br_blockcount - 1)))
+		xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+	if (!info->is_rt &&
+	    (!xfs_verify_fsbno(mp, irec->br_startblock) ||
+	     !xfs_verify_fsbno(mp, irec->br_startblock +
+				irec->br_blockcount - 1)))
+		xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+
+	/* We don't allow unwritten extents on attr forks. */
+	if (irec->br_state == XFS_EXT_UNWRITTEN &&
+	    info->whichfork == XFS_ATTR_FORK)
+		xfs_scrub_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+
+	info->lastoff = irec->br_startoff + irec->br_blockcount;
+	return error;
+}
+
+/* Scrub a bmbt record. */
+STATIC int
+xfs_scrub_bmapbt_rec(
+	struct xfs_scrub_btree		*bs,
+	union xfs_btree_rec		*rec)
+{
+	struct xfs_bmbt_irec		irec;
+	struct xfs_scrub_bmap_info	*info = bs->private;
+	struct xfs_inode		*ip = bs->cur->bc_private.b.ip;
+	struct xfs_buf			*bp = NULL;
+	struct xfs_btree_block		*block;
+	uint64_t			owner;
+	int				i;
+
+	/*
+	 * Check the owners of the btree blocks up to the level below
+	 * the root since the verifiers don't do that.
+	 */
+	if (xfs_sb_version_hascrc(&bs->cur->bc_mp->m_sb) &&
+	    bs->cur->bc_ptrs[0] == 1) {
+		for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
+			block = xfs_btree_get_block(bs->cur, i, &bp);
+			owner = be64_to_cpu(block->bb_u.l.bb_owner);
+			if (owner != ip->i_ino)
+				xfs_scrub_fblock_set_corrupt(bs->sc,
+						info->whichfork, 0);
+		}
+	}
+
+	/* Set up the in-core record and scrub it. */
+	xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
+	return xfs_scrub_bmap_extent(ip, bs->cur, info, &irec);
+}
+
+/* Scan the btree records. */
+STATIC int
+xfs_scrub_bmap_btree(
+	struct xfs_scrub_context	*sc,
+	int				whichfork,
+	struct xfs_scrub_bmap_info	*info)
+{
+	struct xfs_owner_info		oinfo;
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_inode		*ip = sc->ip;
+	struct xfs_btree_cur		*cur;
+	int				error;
+
+	cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
+	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
+	error = xfs_scrub_btree(sc, cur, xfs_scrub_bmapbt_rec, &oinfo, info);
+	xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR :
+					  XFS_BTREE_NOERROR);
+	return error;
+}
+
+/*
+ * Scrub an inode fork's block mappings.
+ *
+ * First we scan every record in every btree block, if applicable.
+ * Then we unconditionally scan the incore extent cache.
+ */
+STATIC int
+xfs_scrub_bmap(
+	struct xfs_scrub_context	*sc,
+	int				whichfork)
+{
+	struct xfs_bmbt_irec		irec;
+	struct xfs_scrub_bmap_info	info = { NULL };
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_inode		*ip = sc->ip;
+	struct xfs_ifork		*ifp;
+	xfs_fileoff_t			endoff;
+	struct xfs_iext_cursor		icur;
+	bool				found;
+	int				error = 0;
+
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+
+	info.is_rt = whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip);
+	info.whichfork = whichfork;
+	info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip);
+	info.sc = sc;
+
+	switch (whichfork) {
+	case XFS_COW_FORK:
+		/* Non-existent CoW forks are ignorable. */
+		if (!ifp)
+			goto out;
+		/* No CoW forks on non-reflink inodes/filesystems. */
+		if (!xfs_is_reflink_inode(ip)) {
+			xfs_scrub_ino_set_corrupt(sc, sc->ip->i_ino, NULL);
+			goto out;
+		}
+		break;
+	case XFS_ATTR_FORK:
+		if (!ifp)
+			goto out;
+		if (!xfs_sb_version_hasattr(&mp->m_sb) &&
+		    !xfs_sb_version_hasattr2(&mp->m_sb))
+			xfs_scrub_ino_set_corrupt(sc, sc->ip->i_ino, NULL);
+		break;
+	default:
+		ASSERT(whichfork == XFS_DATA_FORK);
+		break;
+	}
+
+	/* Check the fork values */
+	switch (XFS_IFORK_FORMAT(ip, whichfork)) {
+	case XFS_DINODE_FMT_UUID:
+	case XFS_DINODE_FMT_DEV:
+	case XFS_DINODE_FMT_LOCAL:
+		/* No mappings to check. */
+		goto out;
+	case XFS_DINODE_FMT_EXTENTS:
+		if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+			xfs_scrub_fblock_set_corrupt(sc, whichfork, 0);
+			goto out;
+		}
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		if (whichfork == XFS_COW_FORK) {
+			xfs_scrub_fblock_set_corrupt(sc, whichfork, 0);
+			goto out;
+		}
+
+		error = xfs_scrub_bmap_btree(sc, whichfork, &info);
+		if (error)
+			goto out;
+		break;
+	default:
+		xfs_scrub_fblock_set_corrupt(sc, whichfork, 0);
+		goto out;
+	}
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/* Now try to scrub the in-memory extent list. */
+        if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		error = xfs_iread_extents(sc->tp, ip, whichfork);
+		if (!xfs_scrub_fblock_process_error(sc, whichfork, 0, &error))
+			goto out;
+	}
+
+	/* Find the offset of the last extent in the mapping. */
+	error = xfs_bmap_last_offset(ip, &endoff, whichfork);
+	if (!xfs_scrub_fblock_process_error(sc, whichfork, 0, &error))
+		goto out;
+
+	/* Scrub extent records. */
+	info.lastoff = 0;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
+	for (found = xfs_iext_lookup_extent(ip, ifp, 0, &icur, &irec);
+	     found != 0;
+	     found = xfs_iext_next_extent(ifp, &icur, &irec)) {
+		if (xfs_scrub_should_terminate(sc, &error))
+			break;
+		if (isnullstartblock(irec.br_startblock))
+			continue;
+		if (irec.br_startoff >= endoff) {
+			xfs_scrub_fblock_set_corrupt(sc, whichfork,
+					irec.br_startoff);
+			goto out;
+		}
+		error = xfs_scrub_bmap_extent(ip, NULL, &info, &irec);
+		if (error)
+			goto out;
+	}
+
+out:
+	return error;
+}
+
+/* Scrub an inode's data fork. */
+int
+xfs_scrub_bmap_data(
+	struct xfs_scrub_context	*sc)
+{
+	return xfs_scrub_bmap(sc, XFS_DATA_FORK);
+}
+
+/* Scrub an inode's attr fork. */
+int
+xfs_scrub_bmap_attr(
+	struct xfs_scrub_context	*sc)
+{
+	return xfs_scrub_bmap(sc, XFS_ATTR_FORK);
+}
+
+/* Scrub an inode's CoW fork. */
+int
+xfs_scrub_bmap_cow(
+	struct xfs_scrub_context	*sc)
+{
+	if (!xfs_is_reflink_inode(sc->ip))
+		return -ENOENT;
+
+	return xfs_scrub_bmap(sc, XFS_COW_FORK);
+}

fs/xfs/scrub/btree.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_alloc.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+
+/* btree scrubbing */
+
+/*
+ * Check for btree operation errors.  See the section about handling
+ * operational errors in common.c.
+ */
+bool
+xfs_scrub_btree_process_error(
+	struct xfs_scrub_context	*sc,
+	struct xfs_btree_cur		*cur,
+	int				level,
+	int				*error)
+{
+	if (*error == 0)
+		return true;
+
+	switch (*error) {
+	case -EDEADLOCK:
+		/* Used to restart an op with deadlock avoidance. */
+		trace_xfs_scrub_deadlock_retry(sc->ip, sc->sm, *error);
+		break;
+	case -EFSBADCRC:
+	case -EFSCORRUPTED:
+		/* Note the badness but don't abort. */
+		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+		*error = 0;
+		/* fall through */
+	default:
+		if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
+			trace_xfs_scrub_ifork_btree_op_error(sc, cur, level,
+					*error, __return_address);
+		else
+			trace_xfs_scrub_btree_op_error(sc, cur, level,
+					*error, __return_address);
+		break;
+	}
+	return false;
+}
+
+/* Record btree block corruption. */
+void
+xfs_scrub_btree_set_corrupt(
+	struct xfs_scrub_context	*sc,
+	struct xfs_btree_cur		*cur,
+	int				level)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+
+	if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
+		trace_xfs_scrub_ifork_btree_error(sc, cur, level,
+				__return_address);
+	else
+		trace_xfs_scrub_btree_error(sc, cur, level,
+				__return_address);
+}
+
+/*
+ * Make sure this record is in order and doesn't stray outside of the parent
+ * keys.
+ */
+STATIC void
+xfs_scrub_btree_rec(
+	struct xfs_scrub_btree	*bs)
+{
+	struct xfs_btree_cur	*cur = bs->cur;
+	union xfs_btree_rec	*rec;
+	union xfs_btree_key	key;
+	union xfs_btree_key	hkey;
+	union xfs_btree_key	*keyp;
+	struct xfs_btree_block	*block;
+	struct xfs_btree_block	*keyblock;
+	struct xfs_buf		*bp;
+
+	block = xfs_btree_get_block(cur, 0, &bp);
+	rec = xfs_btree_rec_addr(cur, cur->bc_ptrs[0], block);
+
+	trace_xfs_scrub_btree_rec(bs->sc, cur, 0);
+
+	/* If this isn't the first record, are they in order? */
+	if (!bs->firstrec && !cur->bc_ops->recs_inorder(cur, &bs->lastrec, rec))
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, 0);
+	bs->firstrec = false;
+	memcpy(&bs->lastrec, rec, cur->bc_ops->rec_len);
+
+	if (cur->bc_nlevels == 1)
+		return;
+
+	/* Is this at least as large as the parent low key? */
+	cur->bc_ops->init_key_from_rec(&key, rec);
+	keyblock = xfs_btree_get_block(cur, 1, &bp);
+	keyp = xfs_btree_key_addr(cur, cur->bc_ptrs[1], keyblock);
+	if (cur->bc_ops->diff_two_keys(cur, &key, keyp) < 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, 1);
+
+	if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
+		return;
+
+	/* Is this no larger than the parent high key? */
+	cur->bc_ops->init_high_key_from_rec(&hkey, rec);
+	keyp = xfs_btree_high_key_addr(cur, cur->bc_ptrs[1], keyblock);
+	if (cur->bc_ops->diff_two_keys(cur, keyp, &hkey) < 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, 1);
+}
+
+/*
+ * Make sure this key is in order and doesn't stray outside of the parent
+ * keys.
+ */
+STATIC void
+xfs_scrub_btree_key(
+	struct xfs_scrub_btree	*bs,
+	int			level)
+{
+	struct xfs_btree_cur	*cur = bs->cur;
+	union xfs_btree_key	*key;
+	union xfs_btree_key	*keyp;
+	struct xfs_btree_block	*block;
+	struct xfs_btree_block	*keyblock;
+	struct xfs_buf		*bp;
+
+	block = xfs_btree_get_block(cur, level, &bp);
+	key = xfs_btree_key_addr(cur, cur->bc_ptrs[level], block);
+
+	trace_xfs_scrub_btree_key(bs->sc, cur, level);
+
+	/* If this isn't the first key, are they in order? */
+	if (!bs->firstkey[level] &&
+	    !cur->bc_ops->keys_inorder(cur, &bs->lastkey[level], key))
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, level);
+	bs->firstkey[level] = false;
+	memcpy(&bs->lastkey[level], key, cur->bc_ops->key_len);
+
+	if (level + 1 >= cur->bc_nlevels)
+		return;
+
+	/* Is this at least as large as the parent low key? */
+	keyblock = xfs_btree_get_block(cur, level + 1, &bp);
+	keyp = xfs_btree_key_addr(cur, cur->bc_ptrs[level + 1], keyblock);
+	if (cur->bc_ops->diff_two_keys(cur, key, keyp) < 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, level);
+
+	if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
+		return;
+
+	/* Is this no larger than the parent high key? */
+	key = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level], block);
+	keyp = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level + 1], keyblock);
+	if (cur->bc_ops->diff_two_keys(cur, keyp, key) < 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, level);
+}
+
+/*
+ * Check a btree pointer.  Returns true if it's ok to use this pointer.
+ * Callers do not need to set the corrupt flag.
+ */
+static bool
+xfs_scrub_btree_ptr_ok(
+	struct xfs_scrub_btree		*bs,
+	int				level,
+	union xfs_btree_ptr		*ptr)
+{
+	bool				res;
+
+	/* A btree rooted in an inode has no block pointer to the root. */
+	if ((bs->cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) &&
+	    level == bs->cur->bc_nlevels)
+		return true;
+
+	/* Otherwise, check the pointers. */
+	if (bs->cur->bc_flags & XFS_BTREE_LONG_PTRS)
+		res = xfs_btree_check_lptr(bs->cur, be64_to_cpu(ptr->l), level);
+	else
+		res = xfs_btree_check_sptr(bs->cur, be32_to_cpu(ptr->s), level);
+	if (!res)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, level);
+
+	return res;
+}
+
+/* Check that a btree block's sibling matches what we expect it. */
+STATIC int
+xfs_scrub_btree_block_check_sibling(
+	struct xfs_scrub_btree		*bs,
+	int				level,
+	int				direction,
+	union xfs_btree_ptr		*sibling)
+{
+	struct xfs_btree_cur		*cur = bs->cur;
+	struct xfs_btree_block		*pblock;
+	struct xfs_buf			*pbp;
+	struct xfs_btree_cur		*ncur = NULL;
+	union xfs_btree_ptr		*pp;
+	int				success;
+	int				error;
+
+	error = xfs_btree_dup_cursor(cur, &ncur);
+	if (!xfs_scrub_btree_process_error(bs->sc, cur, level + 1, &error) ||
+	    !ncur)
+		return error;
+
+	/*
+	 * If the pointer is null, we shouldn't be able to move the upper
+	 * level pointer anywhere.
+	 */
+	if (xfs_btree_ptr_is_null(cur, sibling)) {
+		if (direction > 0)
+			error = xfs_btree_increment(ncur, level + 1, &success);
+		else
+			error = xfs_btree_decrement(ncur, level + 1, &success);
+		if (error == 0 && success)
+			xfs_scrub_btree_set_corrupt(bs->sc, cur, level);
+		error = 0;
+		goto out;
+	}
+
+	/* Increment upper level pointer. */
+	if (direction > 0)
+		error = xfs_btree_increment(ncur, level + 1, &success);
+	else
+		error = xfs_btree_decrement(ncur, level + 1, &success);
+	if (!xfs_scrub_btree_process_error(bs->sc, cur, level + 1, &error))
+		goto out;
+	if (!success) {
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, level + 1);
+		goto out;
+	}
+
+	/* Compare upper level pointer to sibling pointer. */
+	pblock = xfs_btree_get_block(ncur, level + 1, &pbp);
+	pp = xfs_btree_ptr_addr(ncur, ncur->bc_ptrs[level + 1], pblock);
+	if (!xfs_scrub_btree_ptr_ok(bs, level + 1, pp))
+		goto out;
+
+	if (xfs_btree_diff_two_ptrs(cur, pp, sibling))
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, level);
+out:
+	xfs_btree_del_cursor(ncur, XFS_BTREE_ERROR);
+	return error;
+}
+
+/* Check the siblings of a btree block. */
+STATIC int
+xfs_scrub_btree_block_check_siblings(
+	struct xfs_scrub_btree		*bs,
+	struct xfs_btree_block		*block)
+{
+	struct xfs_btree_cur		*cur = bs->cur;
+	union xfs_btree_ptr		leftsib;
+	union xfs_btree_ptr		rightsib;
+	int				level;
+	int				error = 0;
+
+	xfs_btree_get_sibling(cur, block, &leftsib, XFS_BB_LEFTSIB);
+	xfs_btree_get_sibling(cur, block, &rightsib, XFS_BB_RIGHTSIB);
+	level = xfs_btree_get_level(block);
+
+	/* Root block should never have siblings. */
+	if (level == cur->bc_nlevels - 1) {
+		if (!xfs_btree_ptr_is_null(cur, &leftsib) ||
+		    !xfs_btree_ptr_is_null(cur, &rightsib))
+			xfs_scrub_btree_set_corrupt(bs->sc, cur, level);
+		goto out;
+	}
+
+	/*
+	 * Does the left & right sibling pointers match the adjacent
+	 * parent level pointers?
+	 * (These function absorbs error codes for us.)
+	 */
+	error = xfs_scrub_btree_block_check_sibling(bs, level, -1, &leftsib);
+	if (error)
+		return error;
+	error = xfs_scrub_btree_block_check_sibling(bs, level, 1, &rightsib);
+	if (error)
+		return error;
+out:
+	return error;
+}
+
+/*
+ * Grab and scrub a btree block given a btree pointer.  Returns block
+ * and buffer pointers (if applicable) if they're ok to use.
+ */
+STATIC int
+xfs_scrub_btree_get_block(
+	struct xfs_scrub_btree		*bs,
+	int				level,
+	union xfs_btree_ptr		*pp,
+	struct xfs_btree_block		**pblock,
+	struct xfs_buf			**pbp)
+{
+	void				*failed_at;
+	int				error;
+
+	*pblock = NULL;
+	*pbp = NULL;
+
+	error = xfs_btree_lookup_get_block(bs->cur, level, pp, pblock);
+	if (!xfs_scrub_btree_process_error(bs->sc, bs->cur, level, &error) ||
+	    !*pblock)
+		return error;
+
+	xfs_btree_get_block(bs->cur, level, pbp);
+	if (bs->cur->bc_flags & XFS_BTREE_LONG_PTRS)
+		failed_at = __xfs_btree_check_lblock(bs->cur, *pblock,
+				level, *pbp);
+	else
+		failed_at = __xfs_btree_check_sblock(bs->cur, *pblock,
+				 level, *pbp);
+	if (failed_at) {
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, level);
+		return 0;
+	}
+
+	/*
+	 * Check the block's siblings; this function absorbs error codes
+	 * for us.
+	 */
+	return xfs_scrub_btree_block_check_siblings(bs, *pblock);
+}
+
+/*
+ * Check that the low and high keys of this block match the keys stored
+ * in the parent block.
+ */
+STATIC void
+xfs_scrub_btree_block_keys(
+	struct xfs_scrub_btree		*bs,
+	int				level,
+	struct xfs_btree_block		*block)
+{
+	union xfs_btree_key		block_keys;
+	struct xfs_btree_cur		*cur = bs->cur;
+	union xfs_btree_key		*high_bk;
+	union xfs_btree_key		*parent_keys;
+	union xfs_btree_key		*high_pk;
+	struct xfs_btree_block		*parent_block;
+	struct xfs_buf			*bp;
+
+	if (level >= cur->bc_nlevels - 1)
+		return;
+
+	/* Calculate the keys for this block. */
+	xfs_btree_get_keys(cur, block, &block_keys);
+
+	/* Obtain the parent's copy of the keys for this block. */
+	parent_block = xfs_btree_get_block(cur, level + 1, &bp);
+	parent_keys = xfs_btree_key_addr(cur, cur->bc_ptrs[level + 1],
+			parent_block);
+
+	if (cur->bc_ops->diff_two_keys(cur, &block_keys, parent_keys) != 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, 1);
+
+	if (!(cur->bc_flags & XFS_BTREE_OVERLAPPING))
+		return;
+
+	/* Get high keys */
+	high_bk = xfs_btree_high_key_from_key(cur, &block_keys);
+	high_pk = xfs_btree_high_key_addr(cur, cur->bc_ptrs[level + 1],
+			parent_block);
+
+	if (cur->bc_ops->diff_two_keys(cur, high_bk, high_pk) != 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, cur, 1);
+}
+
+/*
+ * Visit all nodes and leaves of a btree.  Check that all pointers and
+ * records are in order, that the keys reflect the records, and use a callback
+ * so that the caller can verify individual records.
+ */
+int
+xfs_scrub_btree(
+	struct xfs_scrub_context	*sc,
+	struct xfs_btree_cur		*cur,
+	xfs_scrub_btree_rec_fn		scrub_fn,
+	struct xfs_owner_info		*oinfo,
+	void				*private)
+{
+	struct xfs_scrub_btree		bs = { NULL };
+	union xfs_btree_ptr		ptr;
+	union xfs_btree_ptr		*pp;
+	union xfs_btree_rec		*recp;
+	struct xfs_btree_block		*block;
+	int				level;
+	struct xfs_buf			*bp;
+	int				i;
+	int				error = 0;
+
+	/* Initialize scrub state */
+	bs.cur = cur;
+	bs.scrub_rec = scrub_fn;
+	bs.oinfo = oinfo;
+	bs.firstrec = true;
+	bs.private = private;
+	bs.sc = sc;
+	for (i = 0; i < XFS_BTREE_MAXLEVELS; i++)
+		bs.firstkey[i] = true;
+	INIT_LIST_HEAD(&bs.to_check);
+
+	/* Don't try to check a tree with a height we can't handle. */
+	if (cur->bc_nlevels > XFS_BTREE_MAXLEVELS) {
+		xfs_scrub_btree_set_corrupt(sc, cur, 0);
+		goto out;
+	}
+
+	/*
+	 * Load the root of the btree.  The helper function absorbs
+	 * error codes for us.
+	 */
+	level = cur->bc_nlevels - 1;
+	cur->bc_ops->init_ptr_from_cur(cur, &ptr);
+	if (!xfs_scrub_btree_ptr_ok(&bs, cur->bc_nlevels, &ptr))
+		goto out;
+	error = xfs_scrub_btree_get_block(&bs, level, &ptr, &block, &bp);
+	if (error || !block)
+		goto out;
+
+	cur->bc_ptrs[level] = 1;
+
+	while (level < cur->bc_nlevels) {
+		block = xfs_btree_get_block(cur, level, &bp);
+
+		if (level == 0) {
+			/* End of leaf, pop back towards the root. */
+			if (cur->bc_ptrs[level] >
+			    be16_to_cpu(block->bb_numrecs)) {
+				xfs_scrub_btree_block_keys(&bs, level, block);
+				if (level < cur->bc_nlevels - 1)
+					cur->bc_ptrs[level + 1]++;
+				level++;
+				continue;
+			}
+
+			/* Records in order for scrub? */
+			xfs_scrub_btree_rec(&bs);
+
+			/* Call out to the record checker. */
+			recp = xfs_btree_rec_addr(cur, cur->bc_ptrs[0], block);
+			error = bs.scrub_rec(&bs, recp);
+			if (error)
+				break;
+			if (xfs_scrub_should_terminate(sc, &error) ||
+			    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+				break;
+
+			cur->bc_ptrs[level]++;
+			continue;
+		}
+
+		/* End of node, pop back towards the root. */
+		if (cur->bc_ptrs[level] > be16_to_cpu(block->bb_numrecs)) {
+			xfs_scrub_btree_block_keys(&bs, level, block);
+			if (level < cur->bc_nlevels - 1)
+				cur->bc_ptrs[level + 1]++;
+			level++;
+			continue;
+		}
+
+		/* Keys in order for scrub? */
+		xfs_scrub_btree_key(&bs, level);
+
+		/* Drill another level deeper. */
+		pp = xfs_btree_ptr_addr(cur, cur->bc_ptrs[level], block);
+		if (!xfs_scrub_btree_ptr_ok(&bs, level, pp)) {
+			cur->bc_ptrs[level]++;
+			continue;
+		}
+		level--;
+		error = xfs_scrub_btree_get_block(&bs, level, pp, &block, &bp);
+		if (error || !block)
+			goto out;
+
+		cur->bc_ptrs[level] = 1;
+	}
+
+out:
+	return error;
+}

fs/xfs/scrub/btree.h

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_SCRUB_BTREE_H__
+#define __XFS_SCRUB_BTREE_H__
+
+/* btree scrub */
+
+/* Check for btree operation errors. */
+bool xfs_scrub_btree_process_error(struct xfs_scrub_context *sc,
+		struct xfs_btree_cur *cur, int level, int *error);
+
+/* Check for btree corruption. */
+void xfs_scrub_btree_set_corrupt(struct xfs_scrub_context *sc,
+		struct xfs_btree_cur *cur, int level);
+
+struct xfs_scrub_btree;
+typedef int (*xfs_scrub_btree_rec_fn)(
+	struct xfs_scrub_btree	*bs,
+	union xfs_btree_rec	*rec);
+
+struct xfs_scrub_btree {
+	/* caller-provided scrub state */
+	struct xfs_scrub_context	*sc;
+	struct xfs_btree_cur		*cur;
+	xfs_scrub_btree_rec_fn		scrub_rec;
+	struct xfs_owner_info		*oinfo;
+	void				*private;
+
+	/* internal scrub state */
+	union xfs_btree_rec		lastrec;
+	bool				firstrec;
+	union xfs_btree_key		lastkey[XFS_BTREE_MAXLEVELS];
+	bool				firstkey[XFS_BTREE_MAXLEVELS];
+	struct list_head		to_check;
+};
+int xfs_scrub_btree(struct xfs_scrub_context *sc, struct xfs_btree_cur *cur,
+		    xfs_scrub_btree_rec_fn scrub_fn,
+		    struct xfs_owner_info *oinfo, void *private);
+
+#endif /* __XFS_SCRUB_BTREE_H__ */

fs/xfs/scrub/common.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_itable.h"
+#include "xfs_alloc.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ialloc.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_refcount.h"
+#include "xfs_refcount_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_log.h"
+#include "xfs_trans_priv.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/btree.h"
+
+/* Common code for the metadata scrubbers. */
+
+/*
+ * Handling operational errors.
+ *
+ * The *_process_error() family of functions are used to process error return
+ * codes from functions called as part of a scrub operation.
+ *
+ * If there's no error, we return true to tell the caller that it's ok
+ * to move on to the next check in its list.
+ *
+ * For non-verifier errors (e.g. ENOMEM) we return false to tell the
+ * caller that something bad happened, and we preserve *error so that
+ * the caller can return the *error up the stack to userspace.
+ *
+ * Verifier errors (EFSBADCRC/EFSCORRUPTED) are recorded by setting
+ * OFLAG_CORRUPT in sm_flags and the *error is cleared.  In other words,
+ * we track verifier errors (and failed scrub checks) via OFLAG_CORRUPT,
+ * not via return codes.  We return false to tell the caller that
+ * something bad happened.  Since the error has been cleared, the caller
+ * will (presumably) return that zero and scrubbing will move on to
+ * whatever's next.
+ *
+ * ftrace can be used to record the precise metadata location and the
+ * approximate code location of the failed operation.
+ */
+
+/* Check for operational errors. */
+bool
+xfs_scrub_process_error(
+	struct xfs_scrub_context	*sc,
+	xfs_agnumber_t			agno,
+	xfs_agblock_t			bno,
+	int				*error)
+{
+	switch (*error) {
+	case 0:
+		return true;
+	case -EDEADLOCK:
+		/* Used to restart an op with deadlock avoidance. */
+		trace_xfs_scrub_deadlock_retry(sc->ip, sc->sm, *error);
+		break;
+	case -EFSBADCRC:
+	case -EFSCORRUPTED:
+		/* Note the badness but don't abort. */
+		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+		*error = 0;
+		/* fall through */
+	default:
+		trace_xfs_scrub_op_error(sc, agno, bno, *error,
+				__return_address);
+		break;
+	}
+	return false;
+}
+
+/* Check for operational errors for a file offset. */
+bool
+xfs_scrub_fblock_process_error(
+	struct xfs_scrub_context	*sc,
+	int				whichfork,
+	xfs_fileoff_t			offset,
+	int				*error)
+{
+	switch (*error) {
+	case 0:
+		return true;
+	case -EDEADLOCK:
+		/* Used to restart an op with deadlock avoidance. */
+		trace_xfs_scrub_deadlock_retry(sc->ip, sc->sm, *error);
+		break;
+	case -EFSBADCRC:
+	case -EFSCORRUPTED:
+		/* Note the badness but don't abort. */
+		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+		*error = 0;
+		/* fall through */
+	default:
+		trace_xfs_scrub_file_op_error(sc, whichfork, offset, *error,
+				__return_address);
+		break;
+	}
+	return false;
+}
+
+/*
+ * Handling scrub corruption/optimization/warning checks.
+ *
+ * The *_set_{corrupt,preen,warning}() family of functions are used to
+ * record the presence of metadata that is incorrect (corrupt), could be
+ * optimized somehow (preen), or should be flagged for administrative
+ * review but is not incorrect (warn).
+ *
+ * ftrace can be used to record the precise metadata location and
+ * approximate code location of the failed check.
+ */
+
+/* Record a block which could be optimized. */
+void
+xfs_scrub_block_set_preen(
+	struct xfs_scrub_context	*sc,
+	struct xfs_buf			*bp)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_PREEN;
+	trace_xfs_scrub_block_preen(sc, bp->b_bn, __return_address);
+}
+
+/*
+ * Record an inode which could be optimized.  The trace data will
+ * include the block given by bp if bp is given; otherwise it will use
+ * the block location of the inode record itself.
+ */
+void
+xfs_scrub_ino_set_preen(
+	struct xfs_scrub_context	*sc,
+	xfs_ino_t			ino,
+	struct xfs_buf			*bp)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_PREEN;
+	trace_xfs_scrub_ino_preen(sc, ino, bp ? bp->b_bn : 0,
+			__return_address);
+}
+
+/* Record a corrupt block. */
+void
+xfs_scrub_block_set_corrupt(
+	struct xfs_scrub_context	*sc,
+	struct xfs_buf			*bp)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+	trace_xfs_scrub_block_error(sc, bp->b_bn, __return_address);
+}
+
+/*
+ * Record a corrupt inode.  The trace data will include the block given
+ * by bp if bp is given; otherwise it will use the block location of the
+ * inode record itself.
+ */
+void
+xfs_scrub_ino_set_corrupt(
+	struct xfs_scrub_context	*sc,
+	xfs_ino_t			ino,
+	struct xfs_buf			*bp)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+	trace_xfs_scrub_ino_error(sc, ino, bp ? bp->b_bn : 0, __return_address);
+}
+
+/* Record corruption in a block indexed by a file fork. */
+void
+xfs_scrub_fblock_set_corrupt(
+	struct xfs_scrub_context	*sc,
+	int				whichfork,
+	xfs_fileoff_t			offset)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+	trace_xfs_scrub_fblock_error(sc, whichfork, offset, __return_address);
+}
+
+/*
+ * Warn about inodes that need administrative review but is not
+ * incorrect.
+ */
+void
+xfs_scrub_ino_set_warning(
+	struct xfs_scrub_context	*sc,
+	xfs_ino_t			ino,
+	struct xfs_buf			*bp)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_WARNING;
+	trace_xfs_scrub_ino_warning(sc, ino, bp ? bp->b_bn : 0,
+			__return_address);
+}
+
+/* Warn about a block indexed by a file fork that needs review. */
+void
+xfs_scrub_fblock_set_warning(
+	struct xfs_scrub_context	*sc,
+	int				whichfork,
+	xfs_fileoff_t			offset)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_WARNING;
+	trace_xfs_scrub_fblock_warning(sc, whichfork, offset, __return_address);
+}
+
+/* Signal an incomplete scrub. */
+void
+xfs_scrub_set_incomplete(
+	struct xfs_scrub_context	*sc)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_INCOMPLETE;
+	trace_xfs_scrub_incomplete(sc, __return_address);
+}
+
+/*
+ * AG scrubbing
+ *
+ * These helpers facilitate locking an allocation group's header
+ * buffers, setting up cursors for all btrees that are present, and
+ * cleaning everything up once we're through.
+ */
+
+/* Decide if we want to return an AG header read failure. */
+static inline bool
+want_ag_read_header_failure(
+	struct xfs_scrub_context	*sc,
+	unsigned int			type)
+{
+	/* Return all AG header read failures when scanning btrees. */
+	if (sc->sm->sm_type != XFS_SCRUB_TYPE_AGF &&
+	    sc->sm->sm_type != XFS_SCRUB_TYPE_AGFL &&
+	    sc->sm->sm_type != XFS_SCRUB_TYPE_AGI)
+		return true;
+	/*
+	 * If we're scanning a given type of AG header, we only want to
+	 * see read failures from that specific header.  We'd like the
+	 * other headers to cross-check them, but this isn't required.
+	 */
+	if (sc->sm->sm_type == type)
+		return true;
+	return false;
+}
+
+/*
+ * Grab all the headers for an AG.
+ *
+ * The headers should be released by xfs_scrub_ag_free, but as a fail
+ * safe we attach all the buffers we grab to the scrub transaction so
+ * they'll all be freed when we cancel it.
+ */
+int
+xfs_scrub_ag_read_headers(
+	struct xfs_scrub_context	*sc,
+	xfs_agnumber_t			agno,
+	struct xfs_buf			**agi,
+	struct xfs_buf			**agf,
+	struct xfs_buf			**agfl)
+{
+	struct xfs_mount		*mp = sc->mp;
+	int				error;
+
+	error = xfs_ialloc_read_agi(mp, sc->tp, agno, agi);
+	if (error && want_ag_read_header_failure(sc, XFS_SCRUB_TYPE_AGI))
+		goto out;
+
+	error = xfs_alloc_read_agf(mp, sc->tp, agno, 0, agf);
+	if (error && want_ag_read_header_failure(sc, XFS_SCRUB_TYPE_AGF))
+		goto out;
+
+	error = xfs_alloc_read_agfl(mp, sc->tp, agno, agfl);
+	if (error && want_ag_read_header_failure(sc, XFS_SCRUB_TYPE_AGFL))
+		goto out;
+
+out:
+	return error;
+}
+
+/* Release all the AG btree cursors. */
+void
+xfs_scrub_ag_btcur_free(
+	struct xfs_scrub_ag		*sa)
+{
+	if (sa->refc_cur)
+		xfs_btree_del_cursor(sa->refc_cur, XFS_BTREE_ERROR);
+	if (sa->rmap_cur)
+		xfs_btree_del_cursor(sa->rmap_cur, XFS_BTREE_ERROR);
+	if (sa->fino_cur)
+		xfs_btree_del_cursor(sa->fino_cur, XFS_BTREE_ERROR);
+	if (sa->ino_cur)
+		xfs_btree_del_cursor(sa->ino_cur, XFS_BTREE_ERROR);
+	if (sa->cnt_cur)
+		xfs_btree_del_cursor(sa->cnt_cur, XFS_BTREE_ERROR);
+	if (sa->bno_cur)
+		xfs_btree_del_cursor(sa->bno_cur, XFS_BTREE_ERROR);
+
+	sa->refc_cur = NULL;
+	sa->rmap_cur = NULL;
+	sa->fino_cur = NULL;
+	sa->ino_cur = NULL;
+	sa->bno_cur = NULL;
+	sa->cnt_cur = NULL;
+}
+
+/* Initialize all the btree cursors for an AG. */
+int
+xfs_scrub_ag_btcur_init(
+	struct xfs_scrub_context	*sc,
+	struct xfs_scrub_ag		*sa)
+{
+	struct xfs_mount		*mp = sc->mp;
+	xfs_agnumber_t			agno = sa->agno;
+
+	if (sa->agf_bp) {
+		/* Set up a bnobt cursor for cross-referencing. */
+		sa->bno_cur = xfs_allocbt_init_cursor(mp, sc->tp, sa->agf_bp,
+				agno, XFS_BTNUM_BNO);
+		if (!sa->bno_cur)
+			goto err;
+
+		/* Set up a cntbt cursor for cross-referencing. */
+		sa->cnt_cur = xfs_allocbt_init_cursor(mp, sc->tp, sa->agf_bp,
+				agno, XFS_BTNUM_CNT);
+		if (!sa->cnt_cur)
+			goto err;
+	}
+
+	/* Set up a inobt cursor for cross-referencing. */
+	if (sa->agi_bp) {
+		sa->ino_cur = xfs_inobt_init_cursor(mp, sc->tp, sa->agi_bp,
+					agno, XFS_BTNUM_INO);
+		if (!sa->ino_cur)
+			goto err;
+	}
+
+	/* Set up a finobt cursor for cross-referencing. */
+	if (sa->agi_bp && xfs_sb_version_hasfinobt(&mp->m_sb)) {
+		sa->fino_cur = xfs_inobt_init_cursor(mp, sc->tp, sa->agi_bp,
+				agno, XFS_BTNUM_FINO);
+		if (!sa->fino_cur)
+			goto err;
+	}
+
+	/* Set up a rmapbt cursor for cross-referencing. */
+	if (sa->agf_bp && xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+		sa->rmap_cur = xfs_rmapbt_init_cursor(mp, sc->tp, sa->agf_bp,
+				agno);
+		if (!sa->rmap_cur)
+			goto err;
+	}
+
+	/* Set up a refcountbt cursor for cross-referencing. */
+	if (sa->agf_bp && xfs_sb_version_hasreflink(&mp->m_sb)) {
+		sa->refc_cur = xfs_refcountbt_init_cursor(mp, sc->tp,
+				sa->agf_bp, agno, NULL);
+		if (!sa->refc_cur)
+			goto err;
+	}
+
+	return 0;
+err:
+	return -ENOMEM;
+}
+
+/* Release the AG header context and btree cursors. */
+void
+xfs_scrub_ag_free(
+	struct xfs_scrub_context	*sc,
+	struct xfs_scrub_ag		*sa)
+{
+	xfs_scrub_ag_btcur_free(sa);
+	if (sa->agfl_bp) {
+		xfs_trans_brelse(sc->tp, sa->agfl_bp);
+		sa->agfl_bp = NULL;
+	}
+	if (sa->agf_bp) {
+		xfs_trans_brelse(sc->tp, sa->agf_bp);
+		sa->agf_bp = NULL;
+	}
+	if (sa->agi_bp) {
+		xfs_trans_brelse(sc->tp, sa->agi_bp);
+		sa->agi_bp = NULL;
+	}
+	sa->agno = NULLAGNUMBER;
+}
+
+/*
+ * For scrub, grab the AGI and the AGF headers, in that order.  Locking
+ * order requires us to get the AGI before the AGF.  We use the
+ * transaction to avoid deadlocking on crosslinked metadata buffers;
+ * either the caller passes one in (bmap scrub) or we have to create a
+ * transaction ourselves.
+ */
+int
+xfs_scrub_ag_init(
+	struct xfs_scrub_context	*sc,
+	xfs_agnumber_t			agno,
+	struct xfs_scrub_ag		*sa)
+{
+	int				error;
+
+	sa->agno = agno;
+	error = xfs_scrub_ag_read_headers(sc, agno, &sa->agi_bp,
+			&sa->agf_bp, &sa->agfl_bp);
+	if (error)
+		return error;
+
+	return xfs_scrub_ag_btcur_init(sc, sa);
+}
+
+/* Per-scrubber setup functions */
+
+/* Set us up with a transaction and an empty context. */
+int
+xfs_scrub_setup_fs(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	return xfs_scrub_trans_alloc(sc->sm, sc->mp, &sc->tp);
+}
+
+/* Set us up with AG headers and btree cursors. */
+int
+xfs_scrub_setup_ag_btree(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip,
+	bool				force_log)
+{
+	struct xfs_mount		*mp = sc->mp;
+	int				error;
+
+	/*
+	 * If the caller asks us to checkpont the log, do so.  This
+	 * expensive operation should be performed infrequently and only
+	 * as a last resort.  Any caller that sets force_log should
+	 * document why they need to do so.
+	 */
+	if (force_log) {
+		error = xfs_scrub_checkpoint_log(mp);
+		if (error)
+			return error;
+	}
+
+	error = xfs_scrub_setup_ag_header(sc, ip);
+	if (error)
+		return error;
+
+	return xfs_scrub_ag_init(sc, sc->sm->sm_agno, &sc->sa);
+}
+
+/* Push everything out of the log onto disk. */
+int
+xfs_scrub_checkpoint_log(
+	struct xfs_mount	*mp)
+{
+	int			error;
+
+	error = _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
+	if (error)
+		return error;
+	xfs_ail_push_all_sync(mp->m_ail);
+	return 0;
+}
+
+/*
+ * Given an inode and the scrub control structure, grab either the
+ * inode referenced in the control structure or the inode passed in.
+ * The inode is not locked.
+ */
+int
+xfs_scrub_get_inode(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip_in)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_inode		*ip = NULL;
+	int				error;
+
+	/*
+	 * If userspace passed us an AG number or a generation number
+	 * without an inode number, they haven't got a clue so bail out
+	 * immediately.
+	 */
+	if (sc->sm->sm_agno || (sc->sm->sm_gen && !sc->sm->sm_ino))
+		return -EINVAL;
+
+	/* We want to scan the inode we already had opened. */
+	if (sc->sm->sm_ino == 0 || sc->sm->sm_ino == ip_in->i_ino) {
+		sc->ip = ip_in;
+		return 0;
+	}
+
+	/* Look up the inode, see if the generation number matches. */
+	if (xfs_internal_inum(mp, sc->sm->sm_ino))
+		return -ENOENT;
+	error = xfs_iget(mp, NULL, sc->sm->sm_ino,
+			XFS_IGET_UNTRUSTED | XFS_IGET_DONTCACHE, 0, &ip);
+	if (error == -ENOENT || error == -EINVAL) {
+		/* inode doesn't exist... */
+		return -ENOENT;
+	} else if (error) {
+		trace_xfs_scrub_op_error(sc,
+				XFS_INO_TO_AGNO(mp, sc->sm->sm_ino),
+				XFS_INO_TO_AGBNO(mp, sc->sm->sm_ino),
+				error, __return_address);
+		return error;
+	}
+	if (VFS_I(ip)->i_generation != sc->sm->sm_gen) {
+		iput(VFS_I(ip));
+		return -ENOENT;
+	}
+
+	sc->ip = ip;
+	return 0;
+}
+
+/* Set us up to scrub a file's contents. */
+int
+xfs_scrub_setup_inode_contents(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip,
+	unsigned int			resblks)
+{
+	struct xfs_mount		*mp = sc->mp;
+	int				error;
+
+	error = xfs_scrub_get_inode(sc, ip);
+	if (error)
+		return error;
+
+	/* Got the inode, lock it and we're ready to go. */
+	sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
+	xfs_ilock(sc->ip, sc->ilock_flags);
+	error = xfs_scrub_trans_alloc(sc->sm, mp, &sc->tp);
+	if (error)
+		goto out;
+	sc->ilock_flags |= XFS_ILOCK_EXCL;
+	xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
+
+out:
+	/* scrub teardown will unlock and release the inode for us */
+	return error;
+}

fs/xfs/scrub/common.h

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_SCRUB_COMMON_H__
+#define __XFS_SCRUB_COMMON_H__
+
+/*
+ * We /could/ terminate a scrub/repair operation early.  If we're not
+ * in a good place to continue (fatal signal, etc.) then bail out.
+ * Note that we're careful not to make any judgements about *error.
+ */
+static inline bool
+xfs_scrub_should_terminate(
+	struct xfs_scrub_context	*sc,
+	int				*error)
+{
+	if (fatal_signal_pending(current)) {
+		if (*error == 0)
+			*error = -EAGAIN;
+		return true;
+	}
+	return false;
+}
+
+/*
+ * Grab an empty transaction so that we can re-grab locked buffers if
+ * one of our btrees turns out to be cyclic.
+ */
+static inline int
+xfs_scrub_trans_alloc(
+	struct xfs_scrub_metadata	*sm,
+	struct xfs_mount		*mp,
+	struct xfs_trans		**tpp)
+{
+	return xfs_trans_alloc_empty(mp, tpp);
+}
+
+bool xfs_scrub_process_error(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
+		xfs_agblock_t bno, int *error);
+bool xfs_scrub_fblock_process_error(struct xfs_scrub_context *sc, int whichfork,
+		xfs_fileoff_t offset, int *error);
+
+void xfs_scrub_block_set_preen(struct xfs_scrub_context *sc,
+		struct xfs_buf *bp);
+void xfs_scrub_ino_set_preen(struct xfs_scrub_context *sc, xfs_ino_t ino,
+		struct xfs_buf *bp);
+
+void xfs_scrub_block_set_corrupt(struct xfs_scrub_context *sc,
+		struct xfs_buf *bp);
+void xfs_scrub_ino_set_corrupt(struct xfs_scrub_context *sc, xfs_ino_t ino,
+		struct xfs_buf *bp);
+void xfs_scrub_fblock_set_corrupt(struct xfs_scrub_context *sc, int whichfork,
+		xfs_fileoff_t offset);
+
+void xfs_scrub_ino_set_warning(struct xfs_scrub_context *sc, xfs_ino_t ino,
+		struct xfs_buf *bp);
+void xfs_scrub_fblock_set_warning(struct xfs_scrub_context *sc, int whichfork,
+		xfs_fileoff_t offset);
+
+void xfs_scrub_set_incomplete(struct xfs_scrub_context *sc);
+int xfs_scrub_checkpoint_log(struct xfs_mount *mp);
+
+/* Setup functions */
+int xfs_scrub_setup_fs(struct xfs_scrub_context *sc, struct xfs_inode *ip);
+int xfs_scrub_setup_ag_header(struct xfs_scrub_context *sc,
+			      struct xfs_inode *ip);
+int xfs_scrub_setup_ag_allocbt(struct xfs_scrub_context *sc,
+			       struct xfs_inode *ip);
+int xfs_scrub_setup_ag_iallocbt(struct xfs_scrub_context *sc,
+				struct xfs_inode *ip);
+int xfs_scrub_setup_ag_rmapbt(struct xfs_scrub_context *sc,
+			      struct xfs_inode *ip);
+int xfs_scrub_setup_ag_refcountbt(struct xfs_scrub_context *sc,
+				  struct xfs_inode *ip);
+int xfs_scrub_setup_inode(struct xfs_scrub_context *sc,
+			  struct xfs_inode *ip);
+int xfs_scrub_setup_inode_bmap(struct xfs_scrub_context *sc,
+			       struct xfs_inode *ip);
+int xfs_scrub_setup_inode_bmap_data(struct xfs_scrub_context *sc,
+				    struct xfs_inode *ip);
+int xfs_scrub_setup_directory(struct xfs_scrub_context *sc,
+			      struct xfs_inode *ip);
+int xfs_scrub_setup_xattr(struct xfs_scrub_context *sc,
+			  struct xfs_inode *ip);
+int xfs_scrub_setup_symlink(struct xfs_scrub_context *sc,
+			    struct xfs_inode *ip);
+int xfs_scrub_setup_parent(struct xfs_scrub_context *sc,
+			   struct xfs_inode *ip);
+#ifdef CONFIG_XFS_RT
+int xfs_scrub_setup_rt(struct xfs_scrub_context *sc, struct xfs_inode *ip);
+#else
+static inline int
+xfs_scrub_setup_rt(struct xfs_scrub_context *sc, struct xfs_inode *ip)
+{
+	return -ENOENT;
+}
+#endif
+#ifdef CONFIG_XFS_QUOTA
+int xfs_scrub_setup_quota(struct xfs_scrub_context *sc, struct xfs_inode *ip);
+#else
+static inline int
+xfs_scrub_setup_quota(struct xfs_scrub_context *sc, struct xfs_inode *ip)
+{
+	return -ENOENT;
+}
+#endif
+
+void xfs_scrub_ag_free(struct xfs_scrub_context *sc, struct xfs_scrub_ag *sa);
+int xfs_scrub_ag_init(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
+		      struct xfs_scrub_ag *sa);
+int xfs_scrub_ag_read_headers(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
+			      struct xfs_buf **agi, struct xfs_buf **agf,
+			      struct xfs_buf **agfl);
+void xfs_scrub_ag_btcur_free(struct xfs_scrub_ag *sa);
+int xfs_scrub_ag_btcur_init(struct xfs_scrub_context *sc,
+			    struct xfs_scrub_ag *sa);
+int xfs_scrub_walk_agfl(struct xfs_scrub_context *sc,
+			int (*fn)(struct xfs_scrub_context *, xfs_agblock_t bno,
+				  void *),
+			void *priv);
+
+int xfs_scrub_setup_ag_btree(struct xfs_scrub_context *sc,
+			     struct xfs_inode *ip, bool force_log);
+int xfs_scrub_get_inode(struct xfs_scrub_context *sc, struct xfs_inode *ip_in);
+int xfs_scrub_setup_inode_contents(struct xfs_scrub_context *sc,
+				   struct xfs_inode *ip, unsigned int resblks);
+
+#endif	/* __XFS_SCRUB_COMMON_H__ */

fs/xfs/scrub/dabtree.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_inode_fork.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_attr_leaf.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/dabtree.h"
+
+/* Directory/Attribute Btree */
+
+/*
+ * Check for da btree operation errors.  See the section about handling
+ * operational errors in common.c.
+ */
+bool
+xfs_scrub_da_process_error(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	int				*error)
+{
+	struct xfs_scrub_context	*sc = ds->sc;
+
+	if (*error == 0)
+		return true;
+
+	switch (*error) {
+	case -EDEADLOCK:
+		/* Used to restart an op with deadlock avoidance. */
+		trace_xfs_scrub_deadlock_retry(sc->ip, sc->sm, *error);
+		break;
+	case -EFSBADCRC:
+	case -EFSCORRUPTED:
+		/* Note the badness but don't abort. */
+		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+		*error = 0;
+		/* fall through */
+	default:
+		trace_xfs_scrub_file_op_error(sc, ds->dargs.whichfork,
+				xfs_dir2_da_to_db(ds->dargs.geo,
+					ds->state->path.blk[level].blkno),
+				*error, __return_address);
+		break;
+	}
+	return false;
+}
+
+/*
+ * Check for da btree corruption.  See the section about handling
+ * operational errors in common.c.
+ */
+void
+xfs_scrub_da_set_corrupt(
+	struct xfs_scrub_da_btree	*ds,
+	int				level)
+{
+	struct xfs_scrub_context	*sc = ds->sc;
+
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+
+	trace_xfs_scrub_fblock_error(sc, ds->dargs.whichfork,
+			xfs_dir2_da_to_db(ds->dargs.geo,
+				ds->state->path.blk[level].blkno),
+			__return_address);
+}
+
+/* Find an entry at a certain level in a da btree. */
+STATIC void *
+xfs_scrub_da_btree_entry(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	int				rec)
+{
+	char				*ents;
+	struct xfs_da_state_blk		*blk;
+	void				*baddr;
+
+	/* Dispatch the entry finding function. */
+	blk = &ds->state->path.blk[level];
+	baddr = blk->bp->b_addr;
+	switch (blk->magic) {
+	case XFS_ATTR_LEAF_MAGIC:
+	case XFS_ATTR3_LEAF_MAGIC:
+		ents = (char *)xfs_attr3_leaf_entryp(baddr);
+		return ents + (rec * sizeof(struct xfs_attr_leaf_entry));
+	case XFS_DIR2_LEAFN_MAGIC:
+	case XFS_DIR3_LEAFN_MAGIC:
+		ents = (char *)ds->dargs.dp->d_ops->leaf_ents_p(baddr);
+		return ents + (rec * sizeof(struct xfs_dir2_leaf_entry));
+	case XFS_DIR2_LEAF1_MAGIC:
+	case XFS_DIR3_LEAF1_MAGIC:
+		ents = (char *)ds->dargs.dp->d_ops->leaf_ents_p(baddr);
+		return ents + (rec * sizeof(struct xfs_dir2_leaf_entry));
+	case XFS_DA_NODE_MAGIC:
+	case XFS_DA3_NODE_MAGIC:
+		ents = (char *)ds->dargs.dp->d_ops->node_tree_p(baddr);
+		return ents + (rec * sizeof(struct xfs_da_node_entry));
+	}
+
+	return NULL;
+}
+
+/* Scrub a da btree hash (key). */
+int
+xfs_scrub_da_btree_hash(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	__be32				*hashp)
+{
+	struct xfs_da_state_blk		*blks;
+	struct xfs_da_node_entry	*entry;
+	xfs_dahash_t			hash;
+	xfs_dahash_t			parent_hash;
+
+	/* Is this hash in order? */
+	hash = be32_to_cpu(*hashp);
+	if (hash < ds->hashes[level])
+		xfs_scrub_da_set_corrupt(ds, level);
+	ds->hashes[level] = hash;
+
+	if (level == 0)
+		return 0;
+
+	/* Is this hash no larger than the parent hash? */
+	blks = ds->state->path.blk;
+	entry = xfs_scrub_da_btree_entry(ds, level - 1, blks[level - 1].index);
+	parent_hash = be32_to_cpu(entry->hashval);
+	if (parent_hash < hash)
+		xfs_scrub_da_set_corrupt(ds, level);
+
+	return 0;
+}
+
+/*
+ * Check a da btree pointer.  Returns true if it's ok to use this
+ * pointer.
+ */
+STATIC bool
+xfs_scrub_da_btree_ptr_ok(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	xfs_dablk_t			blkno)
+{
+	if (blkno < ds->lowest || (ds->highest != 0 && blkno >= ds->highest)) {
+		xfs_scrub_da_set_corrupt(ds, level);
+		return false;
+	}
+
+	return true;
+}
+
+/*
+ * The da btree scrubber can handle leaf1 blocks as a degenerate
+ * form of leafn blocks.  Since the regular da code doesn't handle
+ * leaf1, we must multiplex the verifiers.
+ */
+static void
+xfs_scrub_da_btree_read_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_da_blkinfo	*info = bp->b_addr;
+
+	switch (be16_to_cpu(info->magic)) {
+	case XFS_DIR2_LEAF1_MAGIC:
+	case XFS_DIR3_LEAF1_MAGIC:
+		bp->b_ops = &xfs_dir3_leaf1_buf_ops;
+		bp->b_ops->verify_read(bp);
+		return;
+	default:
+		/*
+		 * xfs_da3_node_buf_ops already know how to handle
+		 * DA*_NODE, ATTR*_LEAF, and DIR*_LEAFN blocks.
+		 */
+		bp->b_ops = &xfs_da3_node_buf_ops;
+		bp->b_ops->verify_read(bp);
+		return;
+	}
+}
+static void
+xfs_scrub_da_btree_write_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_da_blkinfo	*info = bp->b_addr;
+
+	switch (be16_to_cpu(info->magic)) {
+	case XFS_DIR2_LEAF1_MAGIC:
+	case XFS_DIR3_LEAF1_MAGIC:
+		bp->b_ops = &xfs_dir3_leaf1_buf_ops;
+		bp->b_ops->verify_write(bp);
+		return;
+	default:
+		/*
+		 * xfs_da3_node_buf_ops already know how to handle
+		 * DA*_NODE, ATTR*_LEAF, and DIR*_LEAFN blocks.
+		 */
+		bp->b_ops = &xfs_da3_node_buf_ops;
+		bp->b_ops->verify_write(bp);
+		return;
+	}
+}
+
+static const struct xfs_buf_ops xfs_scrub_da_btree_buf_ops = {
+	.name = "xfs_scrub_da_btree",
+	.verify_read = xfs_scrub_da_btree_read_verify,
+	.verify_write = xfs_scrub_da_btree_write_verify,
+};
+
+/* Check a block's sibling. */
+STATIC int
+xfs_scrub_da_btree_block_check_sibling(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	int				direction,
+	xfs_dablk_t			sibling)
+{
+	int				retval;
+	int				error;
+
+	memcpy(&ds->state->altpath, &ds->state->path,
+			sizeof(ds->state->altpath));
+
+	/*
+	 * If the pointer is null, we shouldn't be able to move the upper
+	 * level pointer anywhere.
+	 */
+	if (sibling == 0) {
+		error = xfs_da3_path_shift(ds->state, &ds->state->altpath,
+				direction, false, &retval);
+		if (error == 0 && retval == 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+		error = 0;
+		goto out;
+	}
+
+	/* Move the alternate cursor one block in the direction given. */
+	error = xfs_da3_path_shift(ds->state, &ds->state->altpath,
+			direction, false, &retval);
+	if (!xfs_scrub_da_process_error(ds, level, &error))
+		return error;
+	if (retval) {
+		xfs_scrub_da_set_corrupt(ds, level);
+		return error;
+	}
+
+	/* Compare upper level pointer to sibling pointer. */
+	if (ds->state->altpath.blk[level].blkno != sibling)
+		xfs_scrub_da_set_corrupt(ds, level);
+	xfs_trans_brelse(ds->dargs.trans, ds->state->altpath.blk[level].bp);
+out:
+	return error;
+}
+
+/* Check a block's sibling pointers. */
+STATIC int
+xfs_scrub_da_btree_block_check_siblings(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	struct xfs_da_blkinfo		*hdr)
+{
+	xfs_dablk_t			forw;
+	xfs_dablk_t			back;
+	int				error = 0;
+
+	forw = be32_to_cpu(hdr->forw);
+	back = be32_to_cpu(hdr->back);
+
+	/* Top level blocks should not have sibling pointers. */
+	if (level == 0) {
+		if (forw != 0 || back != 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+		return 0;
+	}
+
+	/*
+	 * Check back (left) and forw (right) pointers.  These functions
+	 * absorb error codes for us.
+	 */
+	error = xfs_scrub_da_btree_block_check_sibling(ds, level, 0, back);
+	if (error)
+		goto out;
+	error = xfs_scrub_da_btree_block_check_sibling(ds, level, 1, forw);
+
+out:
+	memset(&ds->state->altpath, 0, sizeof(ds->state->altpath));
+	return error;
+}
+
+/* Load a dir/attribute block from a btree. */
+STATIC int
+xfs_scrub_da_btree_block(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	xfs_dablk_t			blkno)
+{
+	struct xfs_da_state_blk		*blk;
+	struct xfs_da_intnode		*node;
+	struct xfs_da_node_entry	*btree;
+	struct xfs_da3_blkinfo		*hdr3;
+	struct xfs_da_args		*dargs = &ds->dargs;
+	struct xfs_inode		*ip = ds->dargs.dp;
+	xfs_ino_t			owner;
+	int				*pmaxrecs;
+	struct xfs_da3_icnode_hdr	nodehdr;
+	int				error = 0;
+
+	blk = &ds->state->path.blk[level];
+	ds->state->path.active = level + 1;
+
+	/* Release old block. */
+	if (blk->bp) {
+		xfs_trans_brelse(dargs->trans, blk->bp);
+		blk->bp = NULL;
+	}
+
+	/* Check the pointer. */
+	blk->blkno = blkno;
+	if (!xfs_scrub_da_btree_ptr_ok(ds, level, blkno))
+		goto out_nobuf;
+
+	/* Read the buffer. */
+	error = xfs_da_read_buf(dargs->trans, dargs->dp, blk->blkno, -2,
+			&blk->bp, dargs->whichfork,
+			&xfs_scrub_da_btree_buf_ops);
+	if (!xfs_scrub_da_process_error(ds, level, &error))
+		goto out_nobuf;
+
+	/*
+	 * We didn't find a dir btree root block, which means that
+	 * there's no LEAF1/LEAFN tree (at least not where it's supposed
+	 * to be), so jump out now.
+	 */
+	if (ds->dargs.whichfork == XFS_DATA_FORK && level == 0 &&
+			blk->bp == NULL)
+		goto out_nobuf;
+
+	/* It's /not/ ok for attr trees not to have a da btree. */
+	if (blk->bp == NULL) {
+		xfs_scrub_da_set_corrupt(ds, level);
+		goto out_nobuf;
+	}
+
+	hdr3 = blk->bp->b_addr;
+	blk->magic = be16_to_cpu(hdr3->hdr.magic);
+	pmaxrecs = &ds->maxrecs[level];
+
+	/* We only started zeroing the header on v5 filesystems. */
+	if (xfs_sb_version_hascrc(&ds->sc->mp->m_sb) && hdr3->hdr.pad)
+		xfs_scrub_da_set_corrupt(ds, level);
+
+	/* Check the owner. */
+	if (xfs_sb_version_hascrc(&ip->i_mount->m_sb)) {
+		owner = be64_to_cpu(hdr3->owner);
+		if (owner != ip->i_ino)
+			xfs_scrub_da_set_corrupt(ds, level);
+	}
+
+	/* Check the siblings. */
+	error = xfs_scrub_da_btree_block_check_siblings(ds, level, &hdr3->hdr);
+	if (error)
+		goto out;
+
+	/* Interpret the buffer. */
+	switch (blk->magic) {
+	case XFS_ATTR_LEAF_MAGIC:
+	case XFS_ATTR3_LEAF_MAGIC:
+		xfs_trans_buf_set_type(dargs->trans, blk->bp,
+				XFS_BLFT_ATTR_LEAF_BUF);
+		blk->magic = XFS_ATTR_LEAF_MAGIC;
+		blk->hashval = xfs_attr_leaf_lasthash(blk->bp, pmaxrecs);
+		if (ds->tree_level != 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+		break;
+	case XFS_DIR2_LEAFN_MAGIC:
+	case XFS_DIR3_LEAFN_MAGIC:
+		xfs_trans_buf_set_type(dargs->trans, blk->bp,
+				XFS_BLFT_DIR_LEAFN_BUF);
+		blk->magic = XFS_DIR2_LEAFN_MAGIC;
+		blk->hashval = xfs_dir2_leaf_lasthash(ip, blk->bp, pmaxrecs);
+		if (ds->tree_level != 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+		break;
+	case XFS_DIR2_LEAF1_MAGIC:
+	case XFS_DIR3_LEAF1_MAGIC:
+		xfs_trans_buf_set_type(dargs->trans, blk->bp,
+				XFS_BLFT_DIR_LEAF1_BUF);
+		blk->magic = XFS_DIR2_LEAF1_MAGIC;
+		blk->hashval = xfs_dir2_leaf_lasthash(ip, blk->bp, pmaxrecs);
+		if (ds->tree_level != 0)
+			xfs_scrub_da_set_corrupt(ds, level);
+		break;
+	case XFS_DA_NODE_MAGIC:
+	case XFS_DA3_NODE_MAGIC:
+		xfs_trans_buf_set_type(dargs->trans, blk->bp,
+				XFS_BLFT_DA_NODE_BUF);
+		blk->magic = XFS_DA_NODE_MAGIC;
+		node = blk->bp->b_addr;
+		ip->d_ops->node_hdr_from_disk(&nodehdr, node);
+		btree = ip->d_ops->node_tree_p(node);
+		*pmaxrecs = nodehdr.count;
+		blk->hashval = be32_to_cpu(btree[*pmaxrecs - 1].hashval);
+		if (level == 0) {
+			if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH) {
+				xfs_scrub_da_set_corrupt(ds, level);
+				goto out_freebp;
+			}
+			ds->tree_level = nodehdr.level;
+		} else {
+			if (ds->tree_level != nodehdr.level) {
+				xfs_scrub_da_set_corrupt(ds, level);
+				goto out_freebp;
+			}
+		}
+
+		/* XXX: Check hdr3.pad32 once we know how to fix it. */
+		break;
+	default:
+		xfs_scrub_da_set_corrupt(ds, level);
+		goto out_freebp;
+	}
+
+out:
+	return error;
+out_freebp:
+	xfs_trans_brelse(dargs->trans, blk->bp);
+	blk->bp = NULL;
+out_nobuf:
+	blk->blkno = 0;
+	return error;
+}
+
+/* Visit all nodes and leaves of a da btree. */
+int
+xfs_scrub_da_btree(
+	struct xfs_scrub_context	*sc,
+	int				whichfork,
+	xfs_scrub_da_btree_rec_fn	scrub_fn,
+	void				*private)
+{
+	struct xfs_scrub_da_btree	ds = {};
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_da_state_blk		*blks;
+	struct xfs_da_node_entry	*key;
+	void				*rec;
+	xfs_dablk_t			blkno;
+	int				level;
+	int				error;
+
+	/* Skip short format data structures; no btree to scan. */
+	if (XFS_IFORK_FORMAT(sc->ip, whichfork) != XFS_DINODE_FMT_EXTENTS &&
+	    XFS_IFORK_FORMAT(sc->ip, whichfork) != XFS_DINODE_FMT_BTREE)
+		return 0;
+
+	/* Set up initial da state. */
+	ds.dargs.dp = sc->ip;
+	ds.dargs.whichfork = whichfork;
+	ds.dargs.trans = sc->tp;
+	ds.dargs.op_flags = XFS_DA_OP_OKNOENT;
+	ds.state = xfs_da_state_alloc();
+	ds.state->args = &ds.dargs;
+	ds.state->mp = mp;
+	ds.sc = sc;
+	ds.private = private;
+	if (whichfork == XFS_ATTR_FORK) {
+		ds.dargs.geo = mp->m_attr_geo;
+		ds.lowest = 0;
+		ds.highest = 0;
+	} else {
+		ds.dargs.geo = mp->m_dir_geo;
+		ds.lowest = ds.dargs.geo->leafblk;
+		ds.highest = ds.dargs.geo->freeblk;
+	}
+	blkno = ds.lowest;
+	level = 0;
+
+	/* Find the root of the da tree, if present. */
+	blks = ds.state->path.blk;
+	error = xfs_scrub_da_btree_block(&ds, level, blkno);
+	if (error)
+		goto out_state;
+	/*
+	 * We didn't find a block at ds.lowest, which means that there's
+	 * no LEAF1/LEAFN tree (at least not where it's supposed to be),
+	 * so jump out now.
+	 */
+	if (blks[level].bp == NULL)
+		goto out_state;
+
+	blks[level].index = 0;
+	while (level >= 0 && level < XFS_DA_NODE_MAXDEPTH) {
+		/* Handle leaf block. */
+		if (blks[level].magic != XFS_DA_NODE_MAGIC) {
+			/* End of leaf, pop back towards the root. */
+			if (blks[level].index >= ds.maxrecs[level]) {
+				if (level > 0)
+					blks[level - 1].index++;
+				ds.tree_level++;
+				level--;
+				continue;
+			}
+
+			/* Dispatch record scrubbing. */
+			rec = xfs_scrub_da_btree_entry(&ds, level,
+					blks[level].index);
+			error = scrub_fn(&ds, level, rec);
+			if (error)
+				break;
+			if (xfs_scrub_should_terminate(sc, &error) ||
+			    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+				break;
+
+			blks[level].index++;
+			continue;
+		}
+
+
+		/* End of node, pop back towards the root. */
+		if (blks[level].index >= ds.maxrecs[level]) {
+			if (level > 0)
+				blks[level - 1].index++;
+			ds.tree_level++;
+			level--;
+			continue;
+		}
+
+		/* Hashes in order for scrub? */
+		key = xfs_scrub_da_btree_entry(&ds, level, blks[level].index);
+		error = xfs_scrub_da_btree_hash(&ds, level, &key->hashval);
+		if (error)
+			goto out;
+
+		/* Drill another level deeper. */
+		blkno = be32_to_cpu(key->before);
+		level++;
+		ds.tree_level--;
+		error = xfs_scrub_da_btree_block(&ds, level, blkno);
+		if (error)
+			goto out;
+		if (blks[level].bp == NULL)
+			goto out;
+
+		blks[level].index = 0;
+	}
+
+out:
+	/* Release all the buffers we're tracking. */
+	for (level = 0; level < XFS_DA_NODE_MAXDEPTH; level++) {
+		if (blks[level].bp == NULL)
+			continue;
+		xfs_trans_brelse(sc->tp, blks[level].bp);
+		blks[level].bp = NULL;
+	}
+
+out_state:
+	xfs_da_state_free(ds.state);
+	return error;
+}

fs/xfs/scrub/dabtree.h

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_SCRUB_DABTREE_H__
+#define __XFS_SCRUB_DABTREE_H__
+
+/* dir/attr btree */
+
+struct xfs_scrub_da_btree {
+	struct xfs_da_args		dargs;
+	xfs_dahash_t			hashes[XFS_DA_NODE_MAXDEPTH];
+	int				maxrecs[XFS_DA_NODE_MAXDEPTH];
+	struct xfs_da_state		*state;
+	struct xfs_scrub_context	*sc;
+	void				*private;
+
+	/*
+	 * Lowest and highest directory block address in which we expect
+	 * to find dir/attr btree node blocks.  For a directory this
+	 * (presumably) means between LEAF_OFFSET and FREE_OFFSET; for
+	 * attributes there is no limit.
+	 */
+	xfs_dablk_t			lowest;
+	xfs_dablk_t			highest;
+
+	int				tree_level;
+};
+
+typedef int (*xfs_scrub_da_btree_rec_fn)(struct xfs_scrub_da_btree *ds,
+		int level, void *rec);
+
+/* Check for da btree operation errors. */
+bool xfs_scrub_da_process_error(struct xfs_scrub_da_btree *ds, int level, int *error);
+
+/* Check for da btree corruption. */
+void xfs_scrub_da_set_corrupt(struct xfs_scrub_da_btree *ds, int level);
+
+int xfs_scrub_da_btree_hash(struct xfs_scrub_da_btree *ds, int level,
+			    __be32 *hashp);
+int xfs_scrub_da_btree(struct xfs_scrub_context *sc, int whichfork,
+		       xfs_scrub_da_btree_rec_fn scrub_fn, void *private);
+
+#endif /* __XFS_SCRUB_DABTREE_H__ */

fs/xfs/scrub/dir.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_itable.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_ialloc.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/dabtree.h"
+
+/* Set us up to scrub directories. */
+int
+xfs_scrub_setup_directory(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	return xfs_scrub_setup_inode_contents(sc, ip, 0);
+}
+
+/* Directories */
+
+/* Scrub a directory entry. */
+
+struct xfs_scrub_dir_ctx {
+	/* VFS fill-directory iterator */
+	struct dir_context		dir_iter;
+
+	struct xfs_scrub_context	*sc;
+};
+
+/* Check that an inode's mode matches a given DT_ type. */
+STATIC int
+xfs_scrub_dir_check_ftype(
+	struct xfs_scrub_dir_ctx	*sdc,
+	xfs_fileoff_t			offset,
+	xfs_ino_t			inum,
+	int				dtype)
+{
+	struct xfs_mount		*mp = sdc->sc->mp;
+	struct xfs_inode		*ip;
+	int				ino_dtype;
+	int				error = 0;
+
+	if (!xfs_sb_version_hasftype(&mp->m_sb)) {
+		if (dtype != DT_UNKNOWN && dtype != DT_DIR)
+			xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+					offset);
+		goto out;
+	}
+
+	/*
+	 * Grab the inode pointed to by the dirent.  We release the
+	 * inode before we cancel the scrub transaction.  Since we're
+	 * don't know a priori that releasing the inode won't trigger
+	 * eofblocks cleanup (which allocates what would be a nested
+	 * transaction), we can't use DONTCACHE here because DONTCACHE
+	 * inodes can trigger immediate inactive cleanup of the inode.
+	 */
+	error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip);
+	if (!xfs_scrub_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset,
+			&error))
+		goto out;
+
+	/* Convert mode to the DT_* values that dir_emit uses. */
+	ino_dtype = xfs_dir3_get_dtype(mp,
+			xfs_mode_to_ftype(VFS_I(ip)->i_mode));
+	if (ino_dtype != dtype)
+		xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
+	iput(VFS_I(ip));
+out:
+	return error;
+}
+
+/*
+ * Scrub a single directory entry.
+ *
+ * We use the VFS directory iterator (i.e. readdir) to call this
+ * function for every directory entry in a directory.  Once we're here,
+ * we check the inode number to make sure it's sane, then we check that
+ * we can look up this filename.  Finally, we check the ftype.
+ */
+STATIC int
+xfs_scrub_dir_actor(
+	struct dir_context		*dir_iter,
+	const char			*name,
+	int				namelen,
+	loff_t				pos,
+	u64				ino,
+	unsigned			type)
+{
+	struct xfs_mount		*mp;
+	struct xfs_inode		*ip;
+	struct xfs_scrub_dir_ctx	*sdc;
+	struct xfs_name			xname;
+	xfs_ino_t			lookup_ino;
+	xfs_dablk_t			offset;
+	int				error = 0;
+
+	sdc = container_of(dir_iter, struct xfs_scrub_dir_ctx, dir_iter);
+	ip = sdc->sc->ip;
+	mp = ip->i_mount;
+	offset = xfs_dir2_db_to_da(mp->m_dir_geo,
+			xfs_dir2_dataptr_to_db(mp->m_dir_geo, pos));
+
+	/* Does this inode number make sense? */
+	if (!xfs_verify_dir_ino(mp, ino)) {
+		xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
+		goto out;
+	}
+
+	if (!strncmp(".", name, namelen)) {
+		/* If this is "." then check that the inum matches the dir. */
+		if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
+			xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+					offset);
+		if (ino != ip->i_ino)
+			xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+					offset);
+	} else if (!strncmp("..", name, namelen)) {
+		/*
+		 * If this is ".." in the root inode, check that the inum
+		 * matches this dir.
+		 */
+		if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
+			xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+					offset);
+		if (ip->i_ino == mp->m_sb.sb_rootino && ino != ip->i_ino)
+			xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+					offset);
+	}
+
+	/* Verify that we can look up this name by hash. */
+	xname.name = name;
+	xname.len = namelen;
+	xname.type = XFS_DIR3_FT_UNKNOWN;
+
+	error = xfs_dir_lookup(sdc->sc->tp, ip, &xname, &lookup_ino, NULL);
+	if (!xfs_scrub_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset,
+			&error))
+		goto fail_xref;
+	if (lookup_ino != ino) {
+		xfs_scrub_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
+		goto out;
+	}
+
+	/* Verify the file type.  This function absorbs error codes. */
+	error = xfs_scrub_dir_check_ftype(sdc, offset, lookup_ino, type);
+	if (error)
+		goto out;
+out:
+	return error;
+fail_xref:
+	return error;
+}
+
+/* Scrub a directory btree record. */
+STATIC int
+xfs_scrub_dir_rec(
+	struct xfs_scrub_da_btree	*ds,
+	int				level,
+	void				*rec)
+{
+	struct xfs_mount		*mp = ds->state->mp;
+	struct xfs_dir2_leaf_entry	*ent = rec;
+	struct xfs_inode		*dp = ds->dargs.dp;
+	struct xfs_dir2_data_entry	*dent;
+	struct xfs_buf			*bp;
+	xfs_ino_t			ino;
+	xfs_dablk_t			rec_bno;
+	xfs_dir2_db_t			db;
+	xfs_dir2_data_aoff_t		off;
+	xfs_dir2_dataptr_t		ptr;
+	xfs_dahash_t			calc_hash;
+	xfs_dahash_t			hash;
+	unsigned int			tag;
+	int				error;
+
+	/* Check the hash of the entry. */
+	error = xfs_scrub_da_btree_hash(ds, level, &ent->hashval);
+	if (error)
+		goto out;
+
+	/* Valid hash pointer? */
+	ptr = be32_to_cpu(ent->address);
+	if (ptr == 0)
+		return 0;
+
+	/* Find the directory entry's location. */
+	db = xfs_dir2_dataptr_to_db(mp->m_dir_geo, ptr);
+	off = xfs_dir2_dataptr_to_off(mp->m_dir_geo, ptr);
+	rec_bno = xfs_dir2_db_to_da(mp->m_dir_geo, db);
+
+	if (rec_bno >= mp->m_dir_geo->leafblk) {
+		xfs_scrub_da_set_corrupt(ds, level);
+		goto out;
+	}
+	error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno, -2, &bp);
+	if (!xfs_scrub_fblock_process_error(ds->sc, XFS_DATA_FORK, rec_bno,
+			&error))
+		goto out;
+	if (!bp) {
+		xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		goto out;
+	}
+
+	/* Retrieve the entry, sanity check it, and compare hashes. */
+	dent = (struct xfs_dir2_data_entry *)(((char *)bp->b_addr) + off);
+	ino = be64_to_cpu(dent->inumber);
+	hash = be32_to_cpu(ent->hashval);
+	tag = be16_to_cpup(dp->d_ops->data_entry_tag_p(dent));
+	if (!xfs_verify_dir_ino(mp, ino) || tag != off)
+		xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+	if (dent->namelen == 0) {
+		xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		goto out_relse;
+	}
+	calc_hash = xfs_da_hashname(dent->name, dent->namelen);
+	if (calc_hash != hash)
+		xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+
+out_relse:
+	xfs_trans_brelse(ds->dargs.trans, bp);
+out:
+	return error;
+}
+
+/*
+ * Is this unused entry either in the bestfree or smaller than all of
+ * them?  We've already checked that the bestfrees are sorted longest to
+ * shortest, and that there aren't any bogus entries.
+ */
+STATIC void
+xfs_scrub_directory_check_free_entry(
+	struct xfs_scrub_context	*sc,
+	xfs_dablk_t			lblk,
+	struct xfs_dir2_data_free	*bf,
+	struct xfs_dir2_data_unused	*dup)
+{
+	struct xfs_dir2_data_free	*dfp;
+	unsigned int			dup_length;
+
+	dup_length = be16_to_cpu(dup->length);
+
+	/* Unused entry is shorter than any of the bestfrees */
+	if (dup_length < be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
+		return;
+
+	for (dfp = &bf[XFS_DIR2_DATA_FD_COUNT - 1]; dfp >= bf; dfp--)
+		if (dup_length == be16_to_cpu(dfp->length))
+			return;
+
+	/* Unused entry should be in the bestfrees but wasn't found. */
+	xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+}
+
+/* Check free space info in a directory data block. */
+STATIC int
+xfs_scrub_directory_data_bestfree(
+	struct xfs_scrub_context	*sc,
+	xfs_dablk_t			lblk,
+	bool				is_block)
+{
+	struct xfs_dir2_data_unused	*dup;
+	struct xfs_dir2_data_free	*dfp;
+	struct xfs_buf			*bp;
+	struct xfs_dir2_data_free	*bf;
+	struct xfs_mount		*mp = sc->mp;
+	const struct xfs_dir_ops	*d_ops;
+	char				*ptr;
+	char				*endptr;
+	u16				tag;
+	unsigned int			nr_bestfrees = 0;
+	unsigned int			nr_frees = 0;
+	unsigned int			smallest_bestfree;
+	int				newlen;
+	int				offset;
+	int				error;
+
+	d_ops = sc->ip->d_ops;
+
+	if (is_block) {
+		/* dir block format */
+		if (lblk != XFS_B_TO_FSBT(mp, XFS_DIR2_DATA_OFFSET))
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+		error = xfs_dir3_block_read(sc->tp, sc->ip, &bp);
+	} else {
+		/* dir data format */
+		error = xfs_dir3_data_read(sc->tp, sc->ip, lblk, -1, &bp);
+	}
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
+		goto out;
+
+	/* XXX: Check xfs_dir3_data_hdr.pad is zero once we start setting it. */
+
+	/* Do the bestfrees correspond to actual free space? */
+	bf = d_ops->data_bestfree_p(bp->b_addr);
+	smallest_bestfree = UINT_MAX;
+	for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
+		offset = be16_to_cpu(dfp->offset);
+		if (offset == 0)
+			continue;
+		if (offset >= mp->m_dir_geo->blksize) {
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+			goto out_buf;
+		}
+		dup = (struct xfs_dir2_data_unused *)(bp->b_addr + offset);
+		tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
+
+		/* bestfree doesn't match the entry it points at? */
+		if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG) ||
+		    be16_to_cpu(dup->length) != be16_to_cpu(dfp->length) ||
+		    tag != ((char *)dup - (char *)bp->b_addr)) {
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+			goto out_buf;
+		}
+
+		/* bestfree records should be ordered largest to smallest */
+		if (smallest_bestfree < be16_to_cpu(dfp->length)) {
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+			goto out_buf;
+		}
+
+		smallest_bestfree = be16_to_cpu(dfp->length);
+		nr_bestfrees++;
+	}
+
+	/* Make sure the bestfrees are actually the best free spaces. */
+	ptr = (char *)d_ops->data_entry_p(bp->b_addr);
+	if (is_block) {
+		struct xfs_dir2_block_tail	*btp;
+
+		btp = xfs_dir2_block_tail_p(mp->m_dir_geo, bp->b_addr);
+		endptr = (char *)xfs_dir2_block_leaf_p(btp);
+	} else
+		endptr = (char *)bp->b_addr + BBTOB(bp->b_length);
+
+	/* Iterate the entries, stopping when we hit or go past the end. */
+	while (ptr < endptr) {
+		dup = (struct xfs_dir2_data_unused *)ptr;
+		/* Skip real entries */
+		if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
+			struct xfs_dir2_data_entry	*dep;
+
+			dep = (struct xfs_dir2_data_entry *)ptr;
+			newlen = d_ops->data_entsize(dep->namelen);
+			if (newlen <= 0) {
+				xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+						lblk);
+				goto out_buf;
+			}
+			ptr += newlen;
+			continue;
+		}
+
+		/* Spot check this free entry */
+		tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
+		if (tag != ((char *)dup - (char *)bp->b_addr))
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+
+		/*
+		 * Either this entry is a bestfree or it's smaller than
+		 * any of the bestfrees.
+		 */
+		xfs_scrub_directory_check_free_entry(sc, lblk, bf, dup);
+
+		/* Move on. */
+		newlen = be16_to_cpu(dup->length);
+		if (newlen <= 0) {
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+			goto out_buf;
+		}
+		ptr += newlen;
+		if (ptr <= endptr)
+			nr_frees++;
+	}
+
+	/* We're required to fill all the space. */
+	if (ptr != endptr)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+
+	/* Did we see at least as many free slots as there are bestfrees? */
+	if (nr_frees < nr_bestfrees)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+out_buf:
+	xfs_trans_brelse(sc->tp, bp);
+out:
+	return error;
+}
+
+/*
+ * Does the free space length in the free space index block ($len) match
+ * the longest length in the directory data block's bestfree array?
+ * Assume that we've already checked that the data block's bestfree
+ * array is in order.
+ */
+STATIC void
+xfs_scrub_directory_check_freesp(
+	struct xfs_scrub_context	*sc,
+	xfs_dablk_t			lblk,
+	struct xfs_buf			*dbp,
+	unsigned int			len)
+{
+	struct xfs_dir2_data_free	*dfp;
+
+	dfp = sc->ip->d_ops->data_bestfree_p(dbp->b_addr);
+
+	if (len != be16_to_cpu(dfp->length))
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+
+	if (len > 0 && be16_to_cpu(dfp->offset) == 0)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+}
+
+/* Check free space info in a directory leaf1 block. */
+STATIC int
+xfs_scrub_directory_leaf1_bestfree(
+	struct xfs_scrub_context	*sc,
+	struct xfs_da_args		*args,
+	xfs_dablk_t			lblk)
+{
+	struct xfs_dir3_icleaf_hdr	leafhdr;
+	struct xfs_dir2_leaf_entry	*ents;
+	struct xfs_dir2_leaf_tail	*ltp;
+	struct xfs_dir2_leaf		*leaf;
+	struct xfs_buf			*dbp;
+	struct xfs_buf			*bp;
+	const struct xfs_dir_ops	*d_ops = sc->ip->d_ops;
+	struct xfs_da_geometry		*geo = sc->mp->m_dir_geo;
+	__be16				*bestp;
+	__u16				best;
+	__u32				hash;
+	__u32				lasthash = 0;
+	__u32				bestcount;
+	unsigned int			stale = 0;
+	int				i;
+	int				error;
+
+	/* Read the free space block. */
+	error = xfs_dir3_leaf_read(sc->tp, sc->ip, lblk, -1, &bp);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
+		goto out;
+
+	leaf = bp->b_addr;
+	d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
+	ents = d_ops->leaf_ents_p(leaf);
+	ltp = xfs_dir2_leaf_tail_p(geo, leaf);
+	bestcount = be32_to_cpu(ltp->bestcount);
+	bestp = xfs_dir2_leaf_bests_p(ltp);
+
+	if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
+		struct xfs_dir3_leaf_hdr	*hdr3 = bp->b_addr;
+
+		if (hdr3->pad != cpu_to_be32(0))
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+	}
+
+	/*
+	 * There should be as many bestfree slots as there are dir data
+	 * blocks that can fit under i_size.
+	 */
+	if (bestcount != xfs_dir2_byte_to_db(geo, sc->ip->i_d.di_size)) {
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+		goto out;
+	}
+
+	/* Is the leaf count even remotely sane? */
+	if (leafhdr.count > d_ops->leaf_max_ents(geo)) {
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+		goto out;
+	}
+
+	/* Leaves and bests don't overlap in leaf format. */
+	if ((char *)&ents[leafhdr.count] > (char *)bestp) {
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+		goto out;
+	}
+
+	/* Check hash value order, count stale entries.  */
+	for (i = 0; i < leafhdr.count; i++) {
+		hash = be32_to_cpu(ents[i].hashval);
+		if (i > 0 && lasthash > hash)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+		lasthash = hash;
+		if (ents[i].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
+			stale++;
+	}
+	if (leafhdr.stale != stale)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+
+	/* Check all the bestfree entries. */
+	for (i = 0; i < bestcount; i++, bestp++) {
+		best = be16_to_cpu(*bestp);
+		if (best == NULLDATAOFF)
+			continue;
+		error = xfs_dir3_data_read(sc->tp, sc->ip,
+				i * args->geo->fsbcount, -1, &dbp);
+		if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk,
+				&error))
+			continue;
+		xfs_scrub_directory_check_freesp(sc, lblk, dbp, best);
+		xfs_trans_brelse(sc->tp, dbp);
+	}
+out:
+	return error;
+}
+
+/* Check free space info in a directory freespace block. */
+STATIC int
+xfs_scrub_directory_free_bestfree(
+	struct xfs_scrub_context	*sc,
+	struct xfs_da_args		*args,
+	xfs_dablk_t			lblk)
+{
+	struct xfs_dir3_icfree_hdr	freehdr;
+	struct xfs_buf			*dbp;
+	struct xfs_buf			*bp;
+	__be16				*bestp;
+	__u16				best;
+	unsigned int			stale = 0;
+	int				i;
+	int				error;
+
+	/* Read the free space block */
+	error = xfs_dir2_free_read(sc->tp, sc->ip, lblk, &bp);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
+		goto out;
+
+	if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
+		struct xfs_dir3_free_hdr	*hdr3 = bp->b_addr;
+
+		if (hdr3->pad != cpu_to_be32(0))
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+	}
+
+	/* Check all the entries. */
+	sc->ip->d_ops->free_hdr_from_disk(&freehdr, bp->b_addr);
+	bestp = sc->ip->d_ops->free_bests_p(bp->b_addr);
+	for (i = 0; i < freehdr.nvalid; i++, bestp++) {
+		best = be16_to_cpu(*bestp);
+		if (best == NULLDATAOFF) {
+			stale++;
+			continue;
+		}
+		error = xfs_dir3_data_read(sc->tp, sc->ip,
+				(freehdr.firstdb + i) * args->geo->fsbcount,
+				-1, &dbp);
+		if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk,
+				&error))
+			continue;
+		xfs_scrub_directory_check_freesp(sc, lblk, dbp, best);
+		xfs_trans_brelse(sc->tp, dbp);
+	}
+
+	if (freehdr.nused + stale != freehdr.nvalid)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+out:
+	return error;
+}
+
+/* Check free space information in directories. */
+STATIC int
+xfs_scrub_directory_blocks(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_bmbt_irec		got;
+	struct xfs_da_args		args;
+	struct xfs_ifork		*ifp;
+	struct xfs_mount		*mp = sc->mp;
+	xfs_fileoff_t			leaf_lblk;
+	xfs_fileoff_t			free_lblk;
+	xfs_fileoff_t			lblk;
+	struct xfs_iext_cursor		icur;
+	xfs_dablk_t			dabno;
+	bool				found;
+	int				is_block = 0;
+	int				error;
+
+	/* Ignore local format directories. */
+	if (sc->ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
+	    sc->ip->i_d.di_format != XFS_DINODE_FMT_BTREE)
+		return 0;
+
+	ifp = XFS_IFORK_PTR(sc->ip, XFS_DATA_FORK);
+	lblk = XFS_B_TO_FSB(mp, XFS_DIR2_DATA_OFFSET);
+	leaf_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_LEAF_OFFSET);
+	free_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_FREE_OFFSET);
+
+	/* Is this a block dir? */
+	args.dp = sc->ip;
+	args.geo = mp->m_dir_geo;
+	args.trans = sc->tp;
+	error = xfs_dir2_isblock(&args, &is_block);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
+		goto out;
+
+	/* Iterate all the data extents in the directory... */
+	found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
+	while (found) {
+		/* Block directories only have a single block at offset 0. */
+		if (is_block &&
+		    (got.br_startoff > 0 ||
+		     got.br_blockcount != args.geo->fsbcount)) {
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					got.br_startoff);
+			break;
+		}
+
+		/* No more data blocks... */
+		if (got.br_startoff >= leaf_lblk)
+			break;
+
+		/*
+		 * Check each data block's bestfree data.
+		 *
+		 * Iterate all the fsbcount-aligned block offsets in
+		 * this directory.  The directory block reading code is
+		 * smart enough to do its own bmap lookups to handle
+		 * discontiguous directory blocks.  When we're done
+		 * with the extent record, re-query the bmap at the
+		 * next fsbcount-aligned offset to avoid redundant
+		 * block checks.
+		 */
+		for (lblk = roundup((xfs_dablk_t)got.br_startoff,
+				args.geo->fsbcount);
+		     lblk < got.br_startoff + got.br_blockcount;
+		     lblk += args.geo->fsbcount) {
+			error = xfs_scrub_directory_data_bestfree(sc, lblk,
+					is_block);
+			if (error)
+				goto out;
+		}
+		dabno = got.br_startoff + got.br_blockcount;
+		lblk = roundup(dabno, args.geo->fsbcount);
+		found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
+	}
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/* Look for a leaf1 block, which has free info. */
+	if (xfs_iext_lookup_extent(sc->ip, ifp, leaf_lblk, &icur, &got) &&
+	    got.br_startoff == leaf_lblk &&
+	    got.br_blockcount == args.geo->fsbcount &&
+	    !xfs_iext_next_extent(ifp, &icur, &got)) {
+		if (is_block) {
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+			goto out;
+		}
+		error = xfs_scrub_directory_leaf1_bestfree(sc, &args,
+				leaf_lblk);
+		if (error)
+			goto out;
+	}
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/* Scan for free blocks */
+	lblk = free_lblk;
+	found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
+	while (found) {
+		/*
+		 * Dirs can't have blocks mapped above 2^32.
+		 * Single-block dirs shouldn't even be here.
+		 */
+		lblk = got.br_startoff;
+		if (lblk & ~0xFFFFFFFFULL) {
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+			goto out;
+		}
+		if (is_block) {
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+			goto out;
+		}
+
+		/*
+		 * Check each dir free block's bestfree data.
+		 *
+		 * Iterate all the fsbcount-aligned block offsets in
+		 * this directory.  The directory block reading code is
+		 * smart enough to do its own bmap lookups to handle
+		 * discontiguous directory blocks.  When we're done
+		 * with the extent record, re-query the bmap at the
+		 * next fsbcount-aligned offset to avoid redundant
+		 * block checks.
+		 */
+		for (lblk = roundup((xfs_dablk_t)got.br_startoff,
+				args.geo->fsbcount);
+		     lblk < got.br_startoff + got.br_blockcount;
+		     lblk += args.geo->fsbcount) {
+			error = xfs_scrub_directory_free_bestfree(sc, &args,
+					lblk);
+			if (error)
+				goto out;
+		}
+		dabno = got.br_startoff + got.br_blockcount;
+		lblk = roundup(dabno, args.geo->fsbcount);
+		found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
+	}
+out:
+	return error;
+}
+
+/* Scrub a whole directory. */
+int
+xfs_scrub_directory(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_scrub_dir_ctx	sdc = {
+		.dir_iter.actor = xfs_scrub_dir_actor,
+		.dir_iter.pos = 0,
+		.sc = sc,
+	};
+	size_t				bufsize;
+	loff_t				oldpos;
+	int				error = 0;
+
+	if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
+		return -ENOENT;
+
+	/* Plausible size? */
+	if (sc->ip->i_d.di_size < xfs_dir2_sf_hdr_size(0)) {
+		xfs_scrub_ino_set_corrupt(sc, sc->ip->i_ino, NULL);
+		goto out;
+	}
+
+	/* Check directory tree structure */
+	error = xfs_scrub_da_btree(sc, XFS_DATA_FORK, xfs_scrub_dir_rec, NULL);
+	if (error)
+		return error;
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return error;
+
+	/* Check the freespace. */
+	error = xfs_scrub_directory_blocks(sc);
+	if (error)
+		return error;
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return error;
+
+	/*
+	 * Check that every dirent we see can also be looked up by hash.
+	 * Userspace usually asks for a 32k buffer, so we will too.
+	 */
+	bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE,
+			sc->ip->i_d.di_size);
+
+	/*
+	 * Look up every name in this directory by hash.
+	 *
+	 * Use the xfs_readdir function to call xfs_scrub_dir_actor on
+	 * every directory entry in this directory.  In _actor, we check
+	 * the name, inode number, and ftype (if applicable) of the
+	 * entry.  xfs_readdir uses the VFS filldir functions to provide
+	 * iteration context.
+	 *
+	 * The VFS grabs a read or write lock via i_rwsem before it reads
+	 * or writes to a directory.  If we've gotten this far we've
+	 * already obtained IOLOCK_EXCL, which (since 4.10) is the same as
+	 * getting a write lock on i_rwsem.  Therefore, it is safe for us
+	 * to drop the ILOCK here in order to reuse the _readdir and
+	 * _dir_lookup routines, which do their own ILOCK locking.
+	 */
+	oldpos = 0;
+	sc->ilock_flags &= ~XFS_ILOCK_EXCL;
+	xfs_iunlock(sc->ip, XFS_ILOCK_EXCL);
+	while (true) {
+		error = xfs_readdir(sc->tp, sc->ip, &sdc.dir_iter, bufsize);
+		if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0,
+				&error))
+			goto out;
+		if (oldpos == sdc.dir_iter.pos)
+			break;
+		oldpos = sdc.dir_iter.pos;
+	}
+
+out:
+	return error;
+}

fs/xfs/scrub/ialloc.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_alloc.h"
+#include "xfs_ialloc.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_icache.h"
+#include "xfs_rmap.h"
+#include "xfs_log.h"
+#include "xfs_trans_priv.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+
+/*
+ * Set us up to scrub inode btrees.
+ * If we detect a discrepancy between the inobt and the inode,
+ * try again after forcing logged inode cores out to disk.
+ */
+int
+xfs_scrub_setup_ag_iallocbt(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	return xfs_scrub_setup_ag_btree(sc, ip, sc->try_harder);
+}
+
+/* Inode btree scrubber. */
+
+/* Is this chunk worth checking? */
+STATIC bool
+xfs_scrub_iallocbt_chunk(
+	struct xfs_scrub_btree		*bs,
+	struct xfs_inobt_rec_incore	*irec,
+	xfs_agino_t			agino,
+	xfs_extlen_t			len)
+{
+	struct xfs_mount		*mp = bs->cur->bc_mp;
+	xfs_agnumber_t			agno = bs->cur->bc_private.a.agno;
+	xfs_agblock_t			bno;
+
+	bno = XFS_AGINO_TO_AGBNO(mp, agino);
+	if (bno + len <= bno ||
+	    !xfs_verify_agbno(mp, agno, bno) ||
+	    !xfs_verify_agbno(mp, agno, bno + len - 1))
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	return true;
+}
+
+/* Count the number of free inodes. */
+static unsigned int
+xfs_scrub_iallocbt_freecount(
+	xfs_inofree_t			freemask)
+{
+	BUILD_BUG_ON(sizeof(freemask) != sizeof(__u64));
+	return hweight64(freemask);
+}
+
+/* Check a particular inode with ir_free. */
+STATIC int
+xfs_scrub_iallocbt_check_cluster_freemask(
+	struct xfs_scrub_btree		*bs,
+	xfs_ino_t			fsino,
+	xfs_agino_t			chunkino,
+	xfs_agino_t			clusterino,
+	struct xfs_inobt_rec_incore	*irec,
+	struct xfs_buf			*bp)
+{
+	struct xfs_dinode		*dip;
+	struct xfs_mount		*mp = bs->cur->bc_mp;
+	bool				inode_is_free = false;
+	bool				freemask_ok;
+	bool				inuse;
+	int				error = 0;
+
+	if (xfs_scrub_should_terminate(bs->sc, &error))
+		return error;
+
+	dip = xfs_buf_offset(bp, clusterino * mp->m_sb.sb_inodesize);
+	if (be16_to_cpu(dip->di_magic) != XFS_DINODE_MAGIC ||
+	    (dip->di_version >= 3 &&
+	     be64_to_cpu(dip->di_ino) != fsino + clusterino)) {
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+		goto out;
+	}
+
+	if (irec->ir_free & XFS_INOBT_MASK(chunkino + clusterino))
+		inode_is_free = true;
+	error = xfs_icache_inode_is_allocated(mp, bs->cur->bc_tp,
+			fsino + clusterino, &inuse);
+	if (error == -ENODATA) {
+		/* Not cached, just read the disk buffer */
+		freemask_ok = inode_is_free ^ !!(dip->di_mode);
+		if (!bs->sc->try_harder && !freemask_ok)
+			return -EDEADLOCK;
+	} else if (error < 0) {
+		/*
+		 * Inode is only half assembled, or there was an IO error,
+		 * or the verifier failed, so don't bother trying to check.
+		 * The inode scrubber can deal with this.
+		 */
+		goto out;
+	} else {
+		/* Inode is all there. */
+		freemask_ok = inode_is_free ^ inuse;
+	}
+	if (!freemask_ok)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+out:
+	return 0;
+}
+
+/* Make sure the free mask is consistent with what the inodes think. */
+STATIC int
+xfs_scrub_iallocbt_check_freemask(
+	struct xfs_scrub_btree		*bs,
+	struct xfs_inobt_rec_incore	*irec)
+{
+	struct xfs_owner_info		oinfo;
+	struct xfs_imap			imap;
+	struct xfs_mount		*mp = bs->cur->bc_mp;
+	struct xfs_dinode		*dip;
+	struct xfs_buf			*bp;
+	xfs_ino_t			fsino;
+	xfs_agino_t			nr_inodes;
+	xfs_agino_t			agino;
+	xfs_agino_t			chunkino;
+	xfs_agino_t			clusterino;
+	xfs_agblock_t			agbno;
+	int				blks_per_cluster;
+	uint16_t			holemask;
+	uint16_t			ir_holemask;
+	int				error = 0;
+
+	/* Make sure the freemask matches the inode records. */
+	blks_per_cluster = xfs_icluster_size_fsb(mp);
+	nr_inodes = XFS_OFFBNO_TO_AGINO(mp, blks_per_cluster, 0);
+	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INODES);
+
+	for (agino = irec->ir_startino;
+	     agino < irec->ir_startino + XFS_INODES_PER_CHUNK;
+	     agino += blks_per_cluster * mp->m_sb.sb_inopblock) {
+		fsino = XFS_AGINO_TO_INO(mp, bs->cur->bc_private.a.agno, agino);
+		chunkino = agino - irec->ir_startino;
+		agbno = XFS_AGINO_TO_AGBNO(mp, agino);
+
+		/* Compute the holemask mask for this cluster. */
+		for (clusterino = 0, holemask = 0; clusterino < nr_inodes;
+		     clusterino += XFS_INODES_PER_HOLEMASK_BIT)
+			holemask |= XFS_INOBT_MASK((chunkino + clusterino) /
+					XFS_INODES_PER_HOLEMASK_BIT);
+
+		/* The whole cluster must be a hole or not a hole. */
+		ir_holemask = (irec->ir_holemask & holemask);
+		if (ir_holemask != holemask && ir_holemask != 0) {
+			xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+			continue;
+		}
+
+		/* If any part of this is a hole, skip it. */
+		if (ir_holemask)
+			continue;
+
+		/* Grab the inode cluster buffer. */
+		imap.im_blkno = XFS_AGB_TO_DADDR(mp, bs->cur->bc_private.a.agno,
+				agbno);
+		imap.im_len = XFS_FSB_TO_BB(mp, blks_per_cluster);
+		imap.im_boffset = 0;
+
+		error = xfs_imap_to_bp(mp, bs->cur->bc_tp, &imap,
+				&dip, &bp, 0, 0);
+		if (!xfs_scrub_btree_process_error(bs->sc, bs->cur, 0, &error))
+			continue;
+
+		/* Which inodes are free? */
+		for (clusterino = 0; clusterino < nr_inodes; clusterino++) {
+			error = xfs_scrub_iallocbt_check_cluster_freemask(bs,
+					fsino, chunkino, clusterino, irec, bp);
+			if (error) {
+				xfs_trans_brelse(bs->cur->bc_tp, bp);
+				return error;
+			}
+		}
+
+		xfs_trans_brelse(bs->cur->bc_tp, bp);
+	}
+
+	return error;
+}
+
+/* Scrub an inobt/finobt record. */
+STATIC int
+xfs_scrub_iallocbt_rec(
+	struct xfs_scrub_btree		*bs,
+	union xfs_btree_rec		*rec)
+{
+	struct xfs_mount		*mp = bs->cur->bc_mp;
+	struct xfs_inobt_rec_incore	irec;
+	uint64_t			holes;
+	xfs_agnumber_t			agno = bs->cur->bc_private.a.agno;
+	xfs_agino_t			agino;
+	xfs_agblock_t			agbno;
+	xfs_extlen_t			len;
+	int				holecount;
+	int				i;
+	int				error = 0;
+	unsigned int			real_freecount;
+	uint16_t			holemask;
+
+	xfs_inobt_btrec_to_irec(mp, rec, &irec);
+
+	if (irec.ir_count > XFS_INODES_PER_CHUNK ||
+	    irec.ir_freecount > XFS_INODES_PER_CHUNK)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	real_freecount = irec.ir_freecount +
+			(XFS_INODES_PER_CHUNK - irec.ir_count);
+	if (real_freecount != xfs_scrub_iallocbt_freecount(irec.ir_free))
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	agino = irec.ir_startino;
+	/* Record has to be properly aligned within the AG. */
+	if (!xfs_verify_agino(mp, agno, agino) ||
+	    !xfs_verify_agino(mp, agno, agino + XFS_INODES_PER_CHUNK - 1)) {
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+		goto out;
+	}
+
+	/* Make sure this record is aligned to cluster and inoalignmnt size. */
+	agbno = XFS_AGINO_TO_AGBNO(mp, irec.ir_startino);
+	if ((agbno & (xfs_ialloc_cluster_alignment(mp) - 1)) ||
+	    (agbno & (xfs_icluster_size_fsb(mp) - 1)))
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	/* Handle non-sparse inodes */
+	if (!xfs_inobt_issparse(irec.ir_holemask)) {
+		len = XFS_B_TO_FSB(mp,
+				XFS_INODES_PER_CHUNK * mp->m_sb.sb_inodesize);
+		if (irec.ir_count != XFS_INODES_PER_CHUNK)
+			xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+		if (!xfs_scrub_iallocbt_chunk(bs, &irec, agino, len))
+			goto out;
+		goto check_freemask;
+	}
+
+	/* Check each chunk of a sparse inode cluster. */
+	holemask = irec.ir_holemask;
+	holecount = 0;
+	len = XFS_B_TO_FSB(mp,
+			XFS_INODES_PER_HOLEMASK_BIT * mp->m_sb.sb_inodesize);
+	holes = ~xfs_inobt_irec_to_allocmask(&irec);
+	if ((holes & irec.ir_free) != holes ||
+	    irec.ir_freecount > irec.ir_count)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	for (i = 0; i < XFS_INOBT_HOLEMASK_BITS; i++) {
+		if (holemask & 1)
+			holecount += XFS_INODES_PER_HOLEMASK_BIT;
+		else if (!xfs_scrub_iallocbt_chunk(bs, &irec, agino, len))
+			break;
+		holemask >>= 1;
+		agino += XFS_INODES_PER_HOLEMASK_BIT;
+	}
+
+	if (holecount > XFS_INODES_PER_CHUNK ||
+	    holecount + irec.ir_count != XFS_INODES_PER_CHUNK)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+check_freemask:
+	error = xfs_scrub_iallocbt_check_freemask(bs, &irec);
+	if (error)
+		goto out;
+
+out:
+	return error;
+}
+
+/* Scrub the inode btrees for some AG. */
+STATIC int
+xfs_scrub_iallocbt(
+	struct xfs_scrub_context	*sc,
+	xfs_btnum_t			which)
+{
+	struct xfs_btree_cur		*cur;
+	struct xfs_owner_info		oinfo;
+
+	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INOBT);
+	cur = which == XFS_BTNUM_INO ? sc->sa.ino_cur : sc->sa.fino_cur;
+	return xfs_scrub_btree(sc, cur, xfs_scrub_iallocbt_rec, &oinfo, NULL);
+}
+
+int
+xfs_scrub_inobt(
+	struct xfs_scrub_context	*sc)
+{
+	return xfs_scrub_iallocbt(sc, XFS_BTNUM_INO);
+}
+
+int
+xfs_scrub_finobt(
+	struct xfs_scrub_context	*sc)
+{
+	return xfs_scrub_iallocbt(sc, XFS_BTNUM_FINO);
+}

fs/xfs/scrub/inode.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_inode_buf.h"
+#include "xfs_inode_fork.h"
+#include "xfs_ialloc.h"
+#include "xfs_da_format.h"
+#include "xfs_reflink.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+
+/*
+ * Grab total control of the inode metadata.  It doesn't matter here if
+ * the file data is still changing; exclusive access to the metadata is
+ * the goal.
+ */
+int
+xfs_scrub_setup_inode(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	struct xfs_mount		*mp = sc->mp;
+	int				error;
+
+	/*
+	 * Try to get the inode.  If the verifiers fail, we try again
+	 * in raw mode.
+	 */
+	error = xfs_scrub_get_inode(sc, ip);
+	switch (error) {
+	case 0:
+		break;
+	case -EFSCORRUPTED:
+	case -EFSBADCRC:
+		return 0;
+	default:
+		return error;
+	}
+
+	/* Got the inode, lock it and we're ready to go. */
+	sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
+	xfs_ilock(sc->ip, sc->ilock_flags);
+	error = xfs_scrub_trans_alloc(sc->sm, mp, &sc->tp);
+	if (error)
+		goto out;
+	sc->ilock_flags |= XFS_ILOCK_EXCL;
+	xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
+
+out:
+	/* scrub teardown will unlock and release the inode for us */
+	return error;
+}
+
+/* Inode core */
+
+/*
+ * Validate di_extsize hint.
+ *
+ * The rules are documented at xfs_ioctl_setattr_check_extsize().
+ * These functions must be kept in sync with each other.
+ */
+STATIC void
+xfs_scrub_inode_extsize(
+	struct xfs_scrub_context	*sc,
+	struct xfs_buf			*bp,
+	struct xfs_dinode		*dip,
+	xfs_ino_t			ino,
+	uint16_t			mode,
+	uint16_t			flags)
+{
+	struct xfs_mount		*mp = sc->mp;
+	bool				rt_flag;
+	bool				hint_flag;
+	bool				inherit_flag;
+	uint32_t			extsize;
+	uint32_t			extsize_bytes;
+	uint32_t			blocksize_bytes;
+
+	rt_flag = (flags & XFS_DIFLAG_REALTIME);
+	hint_flag = (flags & XFS_DIFLAG_EXTSIZE);
+	inherit_flag = (flags & XFS_DIFLAG_EXTSZINHERIT);
+	extsize = be32_to_cpu(dip->di_extsize);
+	extsize_bytes = XFS_FSB_TO_B(sc->mp, extsize);
+
+	if (rt_flag)
+		blocksize_bytes = mp->m_sb.sb_rextsize << mp->m_sb.sb_blocklog;
+	else
+		blocksize_bytes = mp->m_sb.sb_blocksize;
+
+	if ((hint_flag || inherit_flag) && !(S_ISDIR(mode) || S_ISREG(mode)))
+		goto bad;
+
+	if (hint_flag && !S_ISREG(mode))
+		goto bad;
+
+	if (inherit_flag && !S_ISDIR(mode))
+		goto bad;
+
+	if ((hint_flag || inherit_flag) && extsize == 0)
+		goto bad;
+
+	if (!(hint_flag || inherit_flag) && extsize != 0)
+		goto bad;
+
+	if (extsize_bytes % blocksize_bytes)
+		goto bad;
+
+	if (extsize > MAXEXTLEN)
+		goto bad;
+
+	if (!rt_flag && extsize > mp->m_sb.sb_agblocks / 2)
+		goto bad;
+
+	return;
+bad:
+	xfs_scrub_ino_set_corrupt(sc, ino, bp);
+}
+
+/*
+ * Validate di_cowextsize hint.
+ *
+ * The rules are documented at xfs_ioctl_setattr_check_cowextsize().
+ * These functions must be kept in sync with each other.
+ */
+STATIC void
+xfs_scrub_inode_cowextsize(
+	struct xfs_scrub_context	*sc,
+	struct xfs_buf			*bp,
+	struct xfs_dinode		*dip,
+	xfs_ino_t			ino,
+	uint16_t			mode,
+	uint16_t			flags,
+	uint64_t			flags2)
+{
+	struct xfs_mount		*mp = sc->mp;
+	bool				rt_flag;
+	bool				hint_flag;
+	uint32_t			extsize;
+	uint32_t			extsize_bytes;
+
+	rt_flag = (flags & XFS_DIFLAG_REALTIME);
+	hint_flag = (flags2 & XFS_DIFLAG2_COWEXTSIZE);
+	extsize = be32_to_cpu(dip->di_cowextsize);
+	extsize_bytes = XFS_FSB_TO_B(sc->mp, extsize);
+
+	if (hint_flag && !xfs_sb_version_hasreflink(&mp->m_sb))
+		goto bad;
+
+	if (hint_flag && !(S_ISDIR(mode) || S_ISREG(mode)))
+		goto bad;
+
+	if (hint_flag && extsize == 0)
+		goto bad;
+
+	if (!hint_flag && extsize != 0)
+		goto bad;
+
+	if (hint_flag && rt_flag)
+		goto bad;
+
+	if (extsize_bytes % mp->m_sb.sb_blocksize)
+		goto bad;
+
+	if (extsize > MAXEXTLEN)
+		goto bad;
+
+	if (extsize > mp->m_sb.sb_agblocks / 2)
+		goto bad;
+
+	return;
+bad:
+	xfs_scrub_ino_set_corrupt(sc, ino, bp);
+}
+
+/* Make sure the di_flags make sense for the inode. */
+STATIC void
+xfs_scrub_inode_flags(
+	struct xfs_scrub_context	*sc,
+	struct xfs_buf			*bp,
+	struct xfs_dinode		*dip,
+	xfs_ino_t			ino,
+	uint16_t			mode,
+	uint16_t			flags)
+{
+	struct xfs_mount		*mp = sc->mp;
+
+	if (flags & ~XFS_DIFLAG_ANY)
+		goto bad;
+
+	/* rt flags require rt device */
+	if ((flags & (XFS_DIFLAG_REALTIME | XFS_DIFLAG_RTINHERIT)) &&
+	    !mp->m_rtdev_targp)
+		goto bad;
+
+	/* new rt bitmap flag only valid for rbmino */
+	if ((flags & XFS_DIFLAG_NEWRTBM) && ino != mp->m_sb.sb_rbmino)
+		goto bad;
+
+	/* directory-only flags */
+	if ((flags & (XFS_DIFLAG_RTINHERIT |
+		     XFS_DIFLAG_EXTSZINHERIT |
+		     XFS_DIFLAG_PROJINHERIT |
+		     XFS_DIFLAG_NOSYMLINKS)) &&
+	    !S_ISDIR(mode))
+		goto bad;
+
+	/* file-only flags */
+	if ((flags & (XFS_DIFLAG_REALTIME | FS_XFLAG_EXTSIZE)) &&
+	    !S_ISREG(mode))
+		goto bad;
+
+	/* filestreams and rt make no sense */
+	if ((flags & XFS_DIFLAG_FILESTREAM) && (flags & XFS_DIFLAG_REALTIME))
+		goto bad;
+
+	return;
+bad:
+	xfs_scrub_ino_set_corrupt(sc, ino, bp);
+}
+
+/* Make sure the di_flags2 make sense for the inode. */
+STATIC void
+xfs_scrub_inode_flags2(
+	struct xfs_scrub_context	*sc,
+	struct xfs_buf			*bp,
+	struct xfs_dinode		*dip,
+	xfs_ino_t			ino,
+	uint16_t			mode,
+	uint16_t			flags,
+	uint64_t			flags2)
+{
+	struct xfs_mount		*mp = sc->mp;
+
+	if (flags2 & ~XFS_DIFLAG2_ANY)
+		goto bad;
+
+	/* reflink flag requires reflink feature */
+	if ((flags2 & XFS_DIFLAG2_REFLINK) &&
+	    !xfs_sb_version_hasreflink(&mp->m_sb))
+		goto bad;
+
+	/* cowextsize flag is checked w.r.t. mode separately */
+
+	/* file/dir-only flags */
+	if ((flags2 & XFS_DIFLAG2_DAX) && !(S_ISREG(mode) || S_ISDIR(mode)))
+		goto bad;
+
+	/* file-only flags */
+	if ((flags2 & XFS_DIFLAG2_REFLINK) && !S_ISREG(mode))
+		goto bad;
+
+	/* realtime and reflink make no sense, currently */
+	if ((flags & XFS_DIFLAG_REALTIME) && (flags2 & XFS_DIFLAG2_REFLINK))
+		goto bad;
+
+	/* dax and reflink make no sense, currently */
+	if ((flags2 & XFS_DIFLAG2_DAX) && (flags2 & XFS_DIFLAG2_REFLINK))
+		goto bad;
+
+	return;
+bad:
+	xfs_scrub_ino_set_corrupt(sc, ino, bp);
+}
+
+/* Scrub all the ondisk inode fields. */
+STATIC void
+xfs_scrub_dinode(
+	struct xfs_scrub_context	*sc,
+	struct xfs_buf			*bp,
+	struct xfs_dinode		*dip,
+	xfs_ino_t			ino)
+{
+	struct xfs_mount		*mp = sc->mp;
+	size_t				fork_recs;
+	unsigned long long		isize;
+	uint64_t			flags2;
+	uint32_t			nextents;
+	uint16_t			flags;
+	uint16_t			mode;
+
+	flags = be16_to_cpu(dip->di_flags);
+	if (dip->di_version >= 3)
+		flags2 = be64_to_cpu(dip->di_flags2);
+	else
+		flags2 = 0;
+
+	/* di_mode */
+	mode = be16_to_cpu(dip->di_mode);
+	if (mode & ~(S_IALLUGO | S_IFMT))
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+	/* v1/v2 fields */
+	switch (dip->di_version) {
+	case 1:
+		/*
+		 * We autoconvert v1 inodes into v2 inodes on writeout,
+		 * so just mark this inode for preening.
+		 */
+		xfs_scrub_ino_set_preen(sc, ino, bp);
+		break;
+	case 2:
+	case 3:
+		if (dip->di_onlink != 0)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+		if (dip->di_mode == 0 && sc->ip)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+		if (dip->di_projid_hi != 0 &&
+		    !xfs_sb_version_hasprojid32bit(&mp->m_sb))
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	default:
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		return;
+	}
+
+	/*
+	 * di_uid/di_gid -- -1 isn't invalid, but there's no way that
+	 * userspace could have created that.
+	 */
+	if (dip->di_uid == cpu_to_be32(-1U) ||
+	    dip->di_gid == cpu_to_be32(-1U))
+		xfs_scrub_ino_set_warning(sc, ino, bp);
+
+	/* di_format */
+	switch (dip->di_format) {
+	case XFS_DINODE_FMT_DEV:
+		if (!S_ISCHR(mode) && !S_ISBLK(mode) &&
+		    !S_ISFIFO(mode) && !S_ISSOCK(mode))
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	case XFS_DINODE_FMT_LOCAL:
+		if (!S_ISDIR(mode) && !S_ISLNK(mode))
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	case XFS_DINODE_FMT_EXTENTS:
+		if (!S_ISREG(mode) && !S_ISDIR(mode) && !S_ISLNK(mode))
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		if (!S_ISREG(mode) && !S_ISDIR(mode))
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	case XFS_DINODE_FMT_UUID:
+	default:
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	}
+
+	/*
+	 * di_size.  xfs_dinode_verify checks for things that screw up
+	 * the VFS such as the upper bit being set and zero-length
+	 * symlinks/directories, but we can do more here.
+	 */
+	isize = be64_to_cpu(dip->di_size);
+	if (isize & (1ULL << 63))
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+	/* Devices, fifos, and sockets must have zero size */
+	if (!S_ISDIR(mode) && !S_ISREG(mode) && !S_ISLNK(mode) && isize != 0)
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+	/* Directories can't be larger than the data section size (32G) */
+	if (S_ISDIR(mode) && (isize == 0 || isize >= XFS_DIR2_SPACE_SIZE))
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+	/* Symlinks can't be larger than SYMLINK_MAXLEN */
+	if (S_ISLNK(mode) && (isize == 0 || isize >= XFS_SYMLINK_MAXLEN))
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+	/*
+	 * Warn if the running kernel can't handle the kinds of offsets
+	 * needed to deal with the file size.  In other words, if the
+	 * pagecache can't cache all the blocks in this file due to
+	 * overly large offsets, flag the inode for admin review.
+	 */
+	if (isize >= mp->m_super->s_maxbytes)
+		xfs_scrub_ino_set_warning(sc, ino, bp);
+
+	/* di_nblocks */
+	if (flags2 & XFS_DIFLAG2_REFLINK) {
+		; /* nblocks can exceed dblocks */
+	} else if (flags & XFS_DIFLAG_REALTIME) {
+		/*
+		 * nblocks is the sum of data extents (in the rtdev),
+		 * attr extents (in the datadev), and both forks' bmbt
+		 * blocks (in the datadev).  This clumsy check is the
+		 * best we can do without cross-referencing with the
+		 * inode forks.
+		 */
+		if (be64_to_cpu(dip->di_nblocks) >=
+		    mp->m_sb.sb_dblocks + mp->m_sb.sb_rblocks)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+	} else {
+		if (be64_to_cpu(dip->di_nblocks) >= mp->m_sb.sb_dblocks)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+	}
+
+	xfs_scrub_inode_flags(sc, bp, dip, ino, mode, flags);
+
+	xfs_scrub_inode_extsize(sc, bp, dip, ino, mode, flags);
+
+	/* di_nextents */
+	nextents = be32_to_cpu(dip->di_nextents);
+	fork_recs =  XFS_DFORK_DSIZE(dip, mp) / sizeof(struct xfs_bmbt_rec);
+	switch (dip->di_format) {
+	case XFS_DINODE_FMT_EXTENTS:
+		if (nextents > fork_recs)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		if (nextents <= fork_recs)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	default:
+		if (nextents != 0)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	}
+
+	/* di_forkoff */
+	if (XFS_DFORK_APTR(dip) >= (char *)dip + mp->m_sb.sb_inodesize)
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+	if (dip->di_anextents != 0 && dip->di_forkoff == 0)
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+	if (dip->di_forkoff == 0 && dip->di_aformat != XFS_DINODE_FMT_EXTENTS)
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+	/* di_aformat */
+	if (dip->di_aformat != XFS_DINODE_FMT_LOCAL &&
+	    dip->di_aformat != XFS_DINODE_FMT_EXTENTS &&
+	    dip->di_aformat != XFS_DINODE_FMT_BTREE)
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+
+	/* di_anextents */
+	nextents = be16_to_cpu(dip->di_anextents);
+	fork_recs =  XFS_DFORK_ASIZE(dip, mp) / sizeof(struct xfs_bmbt_rec);
+	switch (dip->di_aformat) {
+	case XFS_DINODE_FMT_EXTENTS:
+		if (nextents > fork_recs)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	case XFS_DINODE_FMT_BTREE:
+		if (nextents <= fork_recs)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		break;
+	default:
+		if (nextents != 0)
+			xfs_scrub_ino_set_corrupt(sc, ino, bp);
+	}
+
+	if (dip->di_version >= 3) {
+		xfs_scrub_inode_flags2(sc, bp, dip, ino, mode, flags, flags2);
+		xfs_scrub_inode_cowextsize(sc, bp, dip, ino, mode, flags,
+				flags2);
+	}
+}
+
+/* Map and read a raw inode. */
+STATIC int
+xfs_scrub_inode_map_raw(
+	struct xfs_scrub_context	*sc,
+	xfs_ino_t			ino,
+	struct xfs_buf			**bpp,
+	struct xfs_dinode		**dipp)
+{
+	struct xfs_imap			imap;
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_buf			*bp = NULL;
+	struct xfs_dinode		*dip;
+	int				error;
+
+	error = xfs_imap(mp, sc->tp, ino, &imap, XFS_IGET_UNTRUSTED);
+	if (error == -EINVAL) {
+		/*
+		 * Inode could have gotten deleted out from under us;
+		 * just forget about it.
+		 */
+		error = -ENOENT;
+		goto out;
+	}
+	if (!xfs_scrub_process_error(sc, XFS_INO_TO_AGNO(mp, ino),
+			XFS_INO_TO_AGBNO(mp, ino), &error))
+		goto out;
+
+	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
+			imap.im_blkno, imap.im_len, XBF_UNMAPPED, &bp,
+			NULL);
+	if (!xfs_scrub_process_error(sc, XFS_INO_TO_AGNO(mp, ino),
+			XFS_INO_TO_AGBNO(mp, ino), &error))
+		goto out;
+
+	/*
+	 * Is this really an inode?  We disabled verifiers in the above
+	 * xfs_trans_read_buf call because the inode buffer verifier
+	 * fails on /any/ inode record in the inode cluster with a bad
+	 * magic or version number, not just the one that we're
+	 * checking.  Therefore, grab the buffer unconditionally, attach
+	 * the inode verifiers by hand, and run the inode verifier only
+	 * on the one inode we want.
+	 */
+	bp->b_ops = &xfs_inode_buf_ops;
+	dip = xfs_buf_offset(bp, imap.im_boffset);
+	if (!xfs_dinode_verify(mp, ino, dip) ||
+	    !xfs_dinode_good_version(mp, dip->di_version)) {
+		xfs_scrub_ino_set_corrupt(sc, ino, bp);
+		goto out_buf;
+	}
+
+	/* ...and is it the one we asked for? */
+	if (be32_to_cpu(dip->di_gen) != sc->sm->sm_gen) {
+		error = -ENOENT;
+		goto out_buf;
+	}
+
+	*dipp = dip;
+	*bpp = bp;
+out:
+	return error;
+out_buf:
+	xfs_trans_brelse(sc->tp, bp);
+	return error;
+}
+
+/* Scrub an inode. */
+int
+xfs_scrub_inode(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_dinode		di;
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_buf			*bp = NULL;
+	struct xfs_dinode		*dip;
+	xfs_ino_t			ino;
+
+	bool				has_shared;
+	int				error = 0;
+
+	/* Did we get the in-core inode, or are we doing this manually? */
+	if (sc->ip) {
+		ino = sc->ip->i_ino;
+		xfs_inode_to_disk(sc->ip, &di, 0);
+		dip = &di;
+	} else {
+		/* Map & read inode. */
+		ino = sc->sm->sm_ino;
+		error = xfs_scrub_inode_map_raw(sc, ino, &bp, &dip);
+		if (error || !bp)
+			goto out;
+	}
+
+	xfs_scrub_dinode(sc, bp, dip, ino);
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/* Now let's do the things that require a live inode. */
+	if (!sc->ip)
+		goto out;
+
+	/*
+	 * Does this inode have the reflink flag set but no shared extents?
+	 * Set the preening flag if this is the case.
+	 */
+	if (xfs_is_reflink_inode(sc->ip)) {
+		error = xfs_reflink_inode_has_shared_extents(sc->tp, sc->ip,
+				&has_shared);
+		if (!xfs_scrub_process_error(sc, XFS_INO_TO_AGNO(mp, ino),
+				XFS_INO_TO_AGBNO(mp, ino), &error))
+			goto out;
+		if (!has_shared)
+			xfs_scrub_ino_set_preen(sc, ino, bp);
+	}
+
+out:
+	if (bp)
+		xfs_trans_brelse(sc->tp, bp);
+	return error;
+}

fs/xfs/scrub/parent.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_ialloc.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+
+/* Set us up to scrub parents. */
+int
+xfs_scrub_setup_parent(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	return xfs_scrub_setup_inode_contents(sc, ip, 0);
+}
+
+/* Parent pointers */
+
+/* Look for an entry in a parent pointing to this inode. */
+
+struct xfs_scrub_parent_ctx {
+	struct dir_context		dc;
+	xfs_ino_t			ino;
+	xfs_nlink_t			nlink;
+};
+
+/* Look for a single entry in a directory pointing to an inode. */
+STATIC int
+xfs_scrub_parent_actor(
+	struct dir_context		*dc,
+	const char			*name,
+	int				namelen,
+	loff_t				pos,
+	u64				ino,
+	unsigned			type)
+{
+	struct xfs_scrub_parent_ctx	*spc;
+
+	spc = container_of(dc, struct xfs_scrub_parent_ctx, dc);
+	if (spc->ino == ino)
+		spc->nlink++;
+	return 0;
+}
+
+/* Count the number of dentries in the parent dir that point to this inode. */
+STATIC int
+xfs_scrub_parent_count_parent_dentries(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*parent,
+	xfs_nlink_t			*nlink)
+{
+	struct xfs_scrub_parent_ctx	spc = {
+		.dc.actor = xfs_scrub_parent_actor,
+		.dc.pos = 0,
+		.ino = sc->ip->i_ino,
+		.nlink = 0,
+	};
+	size_t				bufsize;
+	loff_t				oldpos;
+	uint				lock_mode;
+	int				error = 0;
+
+	/*
+	 * If there are any blocks, read-ahead block 0 as we're almost
+	 * certain to have the next operation be a read there.  This is
+	 * how we guarantee that the parent's extent map has been loaded,
+	 * if there is one.
+	 */
+	lock_mode = xfs_ilock_data_map_shared(parent);
+	if (parent->i_d.di_nextents > 0)
+		error = xfs_dir3_data_readahead(parent, 0, -1);
+	xfs_iunlock(parent, lock_mode);
+	if (error)
+		return error;
+
+	/*
+	 * Iterate the parent dir to confirm that there is
+	 * exactly one entry pointing back to the inode being
+	 * scanned.
+	 */
+	bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE,
+			parent->i_d.di_size);
+	oldpos = 0;
+	while (true) {
+		error = xfs_readdir(sc->tp, parent, &spc.dc, bufsize);
+		if (error)
+			goto out;
+		if (oldpos == spc.dc.pos)
+			break;
+		oldpos = spc.dc.pos;
+	}
+	*nlink = spc.nlink;
+out:
+	return error;
+}
+
+/*
+ * Given the inode number of the alleged parent of the inode being
+ * scrubbed, try to validate that the parent has exactly one directory
+ * entry pointing back to the inode being scrubbed.
+ */
+STATIC int
+xfs_scrub_parent_validate(
+	struct xfs_scrub_context	*sc,
+	xfs_ino_t			dnum,
+	bool				*try_again)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_inode		*dp = NULL;
+	xfs_nlink_t			expected_nlink;
+	xfs_nlink_t			nlink;
+	int				error = 0;
+
+	*try_again = false;
+
+	/* '..' must not point to ourselves. */
+	if (sc->ip->i_ino == dnum) {
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+		goto out;
+	}
+
+	/*
+	 * If we're an unlinked directory, the parent /won't/ have a link
+	 * to us.  Otherwise, it should have one link.
+	 */
+	expected_nlink = VFS_I(sc->ip)->i_nlink == 0 ? 0 : 1;
+
+	/*
+	 * Grab this parent inode.  We release the inode before we
+	 * cancel the scrub transaction.  Since we're don't know a
+	 * priori that releasing the inode won't trigger eofblocks
+	 * cleanup (which allocates what would be a nested transaction)
+	 * if the parent pointer erroneously points to a file, we
+	 * can't use DONTCACHE here because DONTCACHE inodes can trigger
+	 * immediate inactive cleanup of the inode.
+	 */
+	error = xfs_iget(mp, sc->tp, dnum, 0, 0, &dp);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
+		goto out;
+	if (dp == sc->ip) {
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+		goto out_rele;
+	}
+
+	/*
+	 * We prefer to keep the inode locked while we lock and search
+	 * its alleged parent for a forward reference.  If we can grab
+	 * the iolock, validate the pointers and we're done.  We must
+	 * use nowait here to avoid an ABBA deadlock on the parent and
+	 * the child inodes.
+	 */
+	if (xfs_ilock_nowait(dp, XFS_IOLOCK_SHARED)) {
+		error = xfs_scrub_parent_count_parent_dentries(sc, dp, &nlink);
+		if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0,
+				&error))
+			goto out_unlock;
+		if (nlink != expected_nlink)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+		goto out_unlock;
+	}
+
+	/*
+	 * The game changes if we get here.  We failed to lock the parent,
+	 * so we're going to try to verify both pointers while only holding
+	 * one lock so as to avoid deadlocking with something that's actually
+	 * trying to traverse down the directory tree.
+	 */
+	xfs_iunlock(sc->ip, sc->ilock_flags);
+	sc->ilock_flags = 0;
+	xfs_ilock(dp, XFS_IOLOCK_SHARED);
+
+	/* Go looking for our dentry. */
+	error = xfs_scrub_parent_count_parent_dentries(sc, dp, &nlink);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
+		goto out_unlock;
+
+	/* Drop the parent lock, relock this inode. */
+	xfs_iunlock(dp, XFS_IOLOCK_SHARED);
+	sc->ilock_flags = XFS_IOLOCK_EXCL;
+	xfs_ilock(sc->ip, sc->ilock_flags);
+
+	/*
+	 * If we're an unlinked directory, the parent /won't/ have a link
+	 * to us.  Otherwise, it should have one link.  We have to re-set
+	 * it here because we dropped the lock on sc->ip.
+	 */
+	expected_nlink = VFS_I(sc->ip)->i_nlink == 0 ? 0 : 1;
+
+	/* Look up '..' to see if the inode changed. */
+	error = xfs_dir_lookup(sc->tp, sc->ip, &xfs_name_dotdot, &dnum, NULL);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
+		goto out_rele;
+
+	/* Drat, parent changed.  Try again! */
+	if (dnum != dp->i_ino) {
+		iput(VFS_I(dp));
+		*try_again = true;
+		return 0;
+	}
+	iput(VFS_I(dp));
+
+	/*
+	 * '..' didn't change, so check that there was only one entry
+	 * for us in the parent.
+	 */
+	if (nlink != expected_nlink)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+	return error;
+
+out_unlock:
+	xfs_iunlock(dp, XFS_IOLOCK_SHARED);
+out_rele:
+	iput(VFS_I(dp));
+out:
+	return error;
+}
+
+/* Scrub a parent pointer. */
+int
+xfs_scrub_parent(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_mount		*mp = sc->mp;
+	xfs_ino_t			dnum;
+	bool				try_again;
+	int				tries = 0;
+	int				error = 0;
+
+	/*
+	 * If we're a directory, check that the '..' link points up to
+	 * a directory that has one entry pointing to us.
+	 */
+	if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
+		return -ENOENT;
+
+	/* We're not a special inode, are we? */
+	if (!xfs_verify_dir_ino(mp, sc->ip->i_ino)) {
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+		goto out;
+	}
+
+	/*
+	 * The VFS grabs a read or write lock via i_rwsem before it reads
+	 * or writes to a directory.  If we've gotten this far we've
+	 * already obtained IOLOCK_EXCL, which (since 4.10) is the same as
+	 * getting a write lock on i_rwsem.  Therefore, it is safe for us
+	 * to drop the ILOCK here in order to do directory lookups.
+	 */
+	sc->ilock_flags &= ~(XFS_ILOCK_EXCL | XFS_MMAPLOCK_EXCL);
+	xfs_iunlock(sc->ip, XFS_ILOCK_EXCL | XFS_MMAPLOCK_EXCL);
+
+	/* Look up '..' */
+	error = xfs_dir_lookup(sc->tp, sc->ip, &xfs_name_dotdot, &dnum, NULL);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
+		goto out;
+	if (!xfs_verify_dir_ino(mp, dnum)) {
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+		goto out;
+	}
+
+	/* Is this the root dir?  Then '..' must point to itself. */
+	if (sc->ip == mp->m_rootip) {
+		if (sc->ip->i_ino != mp->m_sb.sb_rootino ||
+		    sc->ip->i_ino != dnum)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+		goto out;
+	}
+
+	do {
+		error = xfs_scrub_parent_validate(sc, dnum, &try_again);
+		if (error)
+			goto out;
+	} while (try_again && ++tries < 20);
+
+	/*
+	 * We gave it our best shot but failed, so mark this scrub
+	 * incomplete.  Userspace can decide if it wants to try again.
+	 */
+	if (try_again && tries == 20)
+		xfs_scrub_set_incomplete(sc);
+out:
+	return error;
+}

fs/xfs/scrub/quota.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_inode_fork.h"
+#include "xfs_alloc.h"
+#include "xfs_bmap.h"
+#include "xfs_quota.h"
+#include "xfs_qm.h"
+#include "xfs_dquot.h"
+#include "xfs_dquot_item.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+
+/* Convert a scrub type code to a DQ flag, or return 0 if error. */
+static inline uint
+xfs_scrub_quota_to_dqtype(
+	struct xfs_scrub_context	*sc)
+{
+	switch (sc->sm->sm_type) {
+	case XFS_SCRUB_TYPE_UQUOTA:
+		return XFS_DQ_USER;
+	case XFS_SCRUB_TYPE_GQUOTA:
+		return XFS_DQ_GROUP;
+	case XFS_SCRUB_TYPE_PQUOTA:
+		return XFS_DQ_PROJ;
+	default:
+		return 0;
+	}
+}
+
+/* Set us up to scrub a quota. */
+int
+xfs_scrub_setup_quota(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	uint				dqtype;
+
+	/*
+	 * If userspace gave us an AG number or inode data, they don't
+	 * know what they're doing.  Get out.
+	 */
+	if (sc->sm->sm_agno || sc->sm->sm_ino || sc->sm->sm_gen)
+		return -EINVAL;
+
+	dqtype = xfs_scrub_quota_to_dqtype(sc);
+	if (dqtype == 0)
+		return -EINVAL;
+	if (!xfs_this_quota_on(sc->mp, dqtype))
+		return -ENOENT;
+	return 0;
+}
+
+/* Quotas. */
+
+/* Scrub the fields in an individual quota item. */
+STATIC void
+xfs_scrub_quota_item(
+	struct xfs_scrub_context	*sc,
+	uint				dqtype,
+	struct xfs_dquot		*dq,
+	xfs_dqid_t			id)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_disk_dquot		*d = &dq->q_core;
+	struct xfs_quotainfo		*qi = mp->m_quotainfo;
+	xfs_fileoff_t			offset;
+	unsigned long long		bsoft;
+	unsigned long long		isoft;
+	unsigned long long		rsoft;
+	unsigned long long		bhard;
+	unsigned long long		ihard;
+	unsigned long long		rhard;
+	unsigned long long		bcount;
+	unsigned long long		icount;
+	unsigned long long		rcount;
+	xfs_ino_t			fs_icount;
+
+	offset = id * qi->qi_dqperchunk;
+
+	/*
+	 * We fed $id and DQNEXT into the xfs_qm_dqget call, which means
+	 * that the actual dquot we got must either have the same id or
+	 * the next higher id.
+	 */
+	if (id > be32_to_cpu(d->d_id))
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/* Did we get the dquot type we wanted? */
+	if (dqtype != (d->d_flags & XFS_DQ_ALLTYPES))
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	if (d->d_pad0 != cpu_to_be32(0) || d->d_pad != cpu_to_be16(0))
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/* Check the limits. */
+	bhard = be64_to_cpu(d->d_blk_hardlimit);
+	ihard = be64_to_cpu(d->d_ino_hardlimit);
+	rhard = be64_to_cpu(d->d_rtb_hardlimit);
+
+	bsoft = be64_to_cpu(d->d_blk_softlimit);
+	isoft = be64_to_cpu(d->d_ino_softlimit);
+	rsoft = be64_to_cpu(d->d_rtb_softlimit);
+
+	/*
+	 * Warn if the hard limits are larger than the fs.
+	 * Administrators can do this, though in production this seems
+	 * suspect, which is why we flag it for review.
+	 *
+	 * Complain about corruption if the soft limit is greater than
+	 * the hard limit.
+	 */
+	if (bhard > mp->m_sb.sb_dblocks)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (bsoft > bhard)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	if (ihard > mp->m_maxicount)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (isoft > ihard)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	if (rhard > mp->m_sb.sb_rblocks)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (rsoft > rhard)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/* Check the resource counts. */
+	bcount = be64_to_cpu(d->d_bcount);
+	icount = be64_to_cpu(d->d_icount);
+	rcount = be64_to_cpu(d->d_rtbcount);
+	fs_icount = percpu_counter_sum(&mp->m_icount);
+
+	/*
+	 * Check that usage doesn't exceed physical limits.  However, on
+	 * a reflink filesystem we're allowed to exceed physical space
+	 * if there are no quota limits.
+	 */
+	if (xfs_sb_version_hasreflink(&mp->m_sb)) {
+		if (mp->m_sb.sb_dblocks < bcount)
+			xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK,
+					offset);
+	} else {
+		if (mp->m_sb.sb_dblocks < bcount)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					offset);
+	}
+	if (icount > fs_icount || rcount > mp->m_sb.sb_rblocks)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/*
+	 * We can violate the hard limits if the admin suddenly sets a
+	 * lower limit than the actual usage.  However, we flag it for
+	 * admin review.
+	 */
+	if (id != 0 && bhard != 0 && bcount > bhard)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (id != 0 && ihard != 0 && icount > ihard)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (id != 0 && rhard != 0 && rcount > rhard)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+}
+
+/* Scrub all of a quota type's items. */
+int
+xfs_scrub_quota(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_bmbt_irec		irec = { 0 };
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_inode		*ip;
+	struct xfs_quotainfo		*qi = mp->m_quotainfo;
+	struct xfs_dquot		*dq;
+	xfs_fileoff_t			max_dqid_off;
+	xfs_fileoff_t			off = 0;
+	xfs_dqid_t			id = 0;
+	uint				dqtype;
+	int				nimaps;
+	int				error;
+
+	if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
+		return -ENOENT;
+
+	mutex_lock(&qi->qi_quotaofflock);
+	dqtype = xfs_scrub_quota_to_dqtype(sc);
+	if (!xfs_this_quota_on(sc->mp, dqtype)) {
+		error = -ENOENT;
+		goto out_unlock_quota;
+	}
+
+	/* Attach to the quota inode and set sc->ip so that reporting works. */
+	ip = xfs_quota_inode(sc->mp, dqtype);
+	sc->ip = ip;
+
+	/* Look for problem extents. */
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
+	if (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) {
+		xfs_scrub_ino_set_corrupt(sc, sc->ip->i_ino, NULL);
+		goto out_unlock_inode;
+	}
+	max_dqid_off = ((xfs_dqid_t)-1) / qi->qi_dqperchunk;
+	while (1) {
+		if (xfs_scrub_should_terminate(sc, &error))
+			break;
+
+		off = irec.br_startoff + irec.br_blockcount;
+		nimaps = 1;
+		error = xfs_bmapi_read(ip, off, -1, &irec, &nimaps,
+				XFS_BMAPI_ENTIRE);
+		if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, off,
+				&error))
+			goto out_unlock_inode;
+		if (!nimaps)
+			break;
+		if (irec.br_startblock == HOLESTARTBLOCK)
+			continue;
+
+		/* Check the extent record doesn't point to crap. */
+		if (irec.br_startblock + irec.br_blockcount <=
+		    irec.br_startblock)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					irec.br_startoff);
+		if (!xfs_verify_fsbno(mp, irec.br_startblock) ||
+		    !xfs_verify_fsbno(mp, irec.br_startblock +
+					irec.br_blockcount - 1))
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					irec.br_startoff);
+
+		/*
+		 * Unwritten extents or blocks mapped above the highest
+		 * quota id shouldn't happen.
+		 */
+		if (isnullstartblock(irec.br_startblock) ||
+		    irec.br_startoff > max_dqid_off ||
+		    irec.br_startoff + irec.br_blockcount > max_dqid_off + 1)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
+	}
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/* Check all the quota items. */
+	while (id < ((xfs_dqid_t)-1ULL)) {
+		if (xfs_scrub_should_terminate(sc, &error))
+			break;
+
+		error = xfs_qm_dqget(mp, NULL, id, dqtype, XFS_QMOPT_DQNEXT,
+				&dq);
+		if (error == -ENOENT)
+			break;
+		if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK,
+				id * qi->qi_dqperchunk, &error))
+			break;
+
+		xfs_scrub_quota_item(sc, dqtype, dq, id);
+
+		id = be32_to_cpu(dq->q_core.d_id) + 1;
+		xfs_qm_dqput(dq);
+		if (!id)
+			break;
+	}
+
+out:
+	/* We set sc->ip earlier, so make sure we clear it now. */
+	sc->ip = NULL;
+out_unlock_quota:
+	mutex_unlock(&qi->qi_quotaofflock);
+	return error;
+
+out_unlock_inode:
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	goto out;
+}

fs/xfs/scrub/refcount.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_alloc.h"
+#include "xfs_rmap.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+
+/*
+ * Set us up to scrub reference count btrees.
+ */
+int
+xfs_scrub_setup_ag_refcountbt(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	return xfs_scrub_setup_ag_btree(sc, ip, false);
+}
+
+/* Reference count btree scrubber. */
+
+/* Scrub a refcountbt record. */
+STATIC int
+xfs_scrub_refcountbt_rec(
+	struct xfs_scrub_btree		*bs,
+	union xfs_btree_rec		*rec)
+{
+	struct xfs_mount		*mp = bs->cur->bc_mp;
+	xfs_agnumber_t			agno = bs->cur->bc_private.a.agno;
+	xfs_agblock_t			bno;
+	xfs_extlen_t			len;
+	xfs_nlink_t			refcount;
+	bool				has_cowflag;
+	int				error = 0;
+
+	bno = be32_to_cpu(rec->refc.rc_startblock);
+	len = be32_to_cpu(rec->refc.rc_blockcount);
+	refcount = be32_to_cpu(rec->refc.rc_refcount);
+
+	/* Only CoW records can have refcount == 1. */
+	has_cowflag = (bno & XFS_REFC_COW_START);
+	if ((refcount == 1 && !has_cowflag) || (refcount != 1 && has_cowflag))
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	/* Check the extent. */
+	bno &= ~XFS_REFC_COW_START;
+	if (bno + len <= bno ||
+	    !xfs_verify_agbno(mp, agno, bno) ||
+	    !xfs_verify_agbno(mp, agno, bno + len - 1))
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	if (refcount == 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	return error;
+}
+
+/* Scrub the refcount btree for some AG. */
+int
+xfs_scrub_refcountbt(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_owner_info		oinfo;
+
+	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_REFC);
+	return xfs_scrub_btree(sc, sc->sa.refc_cur, xfs_scrub_refcountbt_rec,
+			&oinfo, NULL);
+}

fs/xfs/scrub/rmap.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_alloc.h"
+#include "xfs_ialloc.h"
+#include "xfs_rmap.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/trace.h"
+
+/*
+ * Set us up to scrub reverse mapping btrees.
+ */
+int
+xfs_scrub_setup_ag_rmapbt(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	return xfs_scrub_setup_ag_btree(sc, ip, false);
+}
+
+/* Reverse-mapping scrubber. */
+
+/* Scrub an rmapbt record. */
+STATIC int
+xfs_scrub_rmapbt_rec(
+	struct xfs_scrub_btree		*bs,
+	union xfs_btree_rec		*rec)
+{
+	struct xfs_mount		*mp = bs->cur->bc_mp;
+	struct xfs_rmap_irec		irec;
+	xfs_agnumber_t			agno = bs->cur->bc_private.a.agno;
+	bool				non_inode;
+	bool				is_unwritten;
+	bool				is_bmbt;
+	bool				is_attr;
+	int				error;
+
+	error = xfs_rmap_btrec_to_irec(rec, &irec);
+	if (!xfs_scrub_btree_process_error(bs->sc, bs->cur, 0, &error))
+		goto out;
+
+	/* Check extent. */
+	if (irec.rm_startblock + irec.rm_blockcount <= irec.rm_startblock)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	if (irec.rm_owner == XFS_RMAP_OWN_FS) {
+		/*
+		 * xfs_verify_agbno returns false for static fs metadata.
+		 * Since that only exists at the start of the AG, validate
+		 * that by hand.
+		 */
+		if (irec.rm_startblock != 0 ||
+		    irec.rm_blockcount != XFS_AGFL_BLOCK(mp) + 1)
+			xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+	} else {
+		/*
+		 * Otherwise we must point somewhere past the static metadata
+		 * but before the end of the FS.  Run the regular check.
+		 */
+		if (!xfs_verify_agbno(mp, agno, irec.rm_startblock) ||
+		    !xfs_verify_agbno(mp, agno, irec.rm_startblock +
+				irec.rm_blockcount - 1))
+			xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+	}
+
+	/* Check flags. */
+	non_inode = XFS_RMAP_NON_INODE_OWNER(irec.rm_owner);
+	is_bmbt = irec.rm_flags & XFS_RMAP_BMBT_BLOCK;
+	is_attr = irec.rm_flags & XFS_RMAP_ATTR_FORK;
+	is_unwritten = irec.rm_flags & XFS_RMAP_UNWRITTEN;
+
+	if (is_bmbt && irec.rm_offset != 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	if (non_inode && irec.rm_offset != 0)
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	if (is_unwritten && (is_bmbt || non_inode || is_attr))
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	if (non_inode && (is_bmbt || is_unwritten || is_attr))
+		xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	if (!non_inode) {
+		if (!xfs_verify_ino(mp, irec.rm_owner))
+			xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+	} else {
+		/* Non-inode owner within the magic values? */
+		if (irec.rm_owner <= XFS_RMAP_OWN_MIN ||
+		    irec.rm_owner > XFS_RMAP_OWN_FS)
+			xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
+	}
+out:
+	return error;
+}
+
+/* Scrub the rmap btree for some AG. */
+int
+xfs_scrub_rmapbt(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_owner_info		oinfo;
+
+	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
+	return xfs_scrub_btree(sc, sc->sa.rmap_cur, xfs_scrub_rmapbt_rec,
+			&oinfo, NULL);
+}

fs/xfs/scrub/rtbitmap.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_alloc.h"
+#include "xfs_rtalloc.h"
+#include "xfs_inode.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+
+/* Set us up with the realtime metadata locked. */
+int
+xfs_scrub_setup_rt(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	struct xfs_mount		*mp = sc->mp;
+	int				error = 0;
+
+	/*
+	 * If userspace gave us an AG number or inode data, they don't
+	 * know what they're doing.  Get out.
+	 */
+	if (sc->sm->sm_agno || sc->sm->sm_ino || sc->sm->sm_gen)
+		return -EINVAL;
+
+	error = xfs_scrub_setup_fs(sc, ip);
+	if (error)
+		return error;
+
+	sc->ilock_flags = XFS_ILOCK_EXCL | XFS_ILOCK_RTBITMAP;
+	sc->ip = mp->m_rbmip;
+	xfs_ilock(sc->ip, sc->ilock_flags);
+
+	return 0;
+}
+
+/* Realtime bitmap. */
+
+/* Scrub a free extent record from the realtime bitmap. */
+STATIC int
+xfs_scrub_rtbitmap_rec(
+	struct xfs_trans		*tp,
+	struct xfs_rtalloc_rec		*rec,
+	void				*priv)
+{
+	struct xfs_scrub_context	*sc = priv;
+
+	if (rec->ar_startblock + rec->ar_blockcount <= rec->ar_startblock ||
+	    !xfs_verify_rtbno(sc->mp, rec->ar_startblock) ||
+	    !xfs_verify_rtbno(sc->mp, rec->ar_startblock +
+			rec->ar_blockcount - 1))
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+	return 0;
+}
+
+/* Scrub the realtime bitmap. */
+int
+xfs_scrub_rtbitmap(
+	struct xfs_scrub_context	*sc)
+{
+	int				error;
+
+	error = xfs_rtalloc_query_all(sc->tp, xfs_scrub_rtbitmap_rec, sc);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
+		goto out;
+
+out:
+	return error;
+}
+
+/* Scrub the realtime summary. */
+int
+xfs_scrub_rtsummary(
+	struct xfs_scrub_context	*sc)
+{
+	/* XXX: implement this some day */
+	return -ENOENT;
+}

fs/xfs/scrub/scrub.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_itable.h"
+#include "xfs_alloc.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ialloc.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_refcount.h"
+#include "xfs_refcount_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/scrub.h"
+#include "scrub/btree.h"
+
+/*
+ * Online Scrub and Repair
+ *
+ * Traditionally, XFS (the kernel driver) did not know how to check or
+ * repair on-disk data structures.  That task was left to the xfs_check
+ * and xfs_repair tools, both of which require taking the filesystem
+ * offline for a thorough but time consuming examination.  Online
+ * scrub & repair, on the other hand, enables us to check the metadata
+ * for obvious errors while carefully stepping around the filesystem's
+ * ongoing operations, locking rules, etc.
+ *
+ * Given that most XFS metadata consist of records stored in a btree,
+ * most of the checking functions iterate the btree blocks themselves
+ * looking for irregularities.  When a record block is encountered, each
+ * record can be checked for obviously bad values.  Record values can
+ * also be cross-referenced against other btrees to look for potential
+ * misunderstandings between pieces of metadata.
+ *
+ * It is expected that the checkers responsible for per-AG metadata
+ * structures will lock the AG headers (AGI, AGF, AGFL), iterate the
+ * metadata structure, and perform any relevant cross-referencing before
+ * unlocking the AG and returning the results to userspace.  These
+ * scrubbers must not keep an AG locked for too long to avoid tying up
+ * the block and inode allocators.
+ *
+ * Block maps and b-trees rooted in an inode present a special challenge
+ * because they can involve extents from any AG.  The general scrubber
+ * structure of lock -> check -> xref -> unlock still holds, but AG
+ * locking order rules /must/ be obeyed to avoid deadlocks.  The
+ * ordering rule, of course, is that we must lock in increasing AG
+ * order.  Helper functions are provided to track which AG headers we've
+ * already locked.  If we detect an imminent locking order violation, we
+ * can signal a potential deadlock, in which case the scrubber can jump
+ * out to the top level, lock all the AGs in order, and retry the scrub.
+ *
+ * For file data (directories, extended attributes, symlinks) scrub, we
+ * can simply lock the inode and walk the data.  For btree data
+ * (directories and attributes) we follow the same btree-scrubbing
+ * strategy outlined previously to check the records.
+ *
+ * We use a bit of trickery with transactions to avoid buffer deadlocks
+ * if there is a cycle in the metadata.  The basic problem is that
+ * travelling down a btree involves locking the current buffer at each
+ * tree level.  If a pointer should somehow point back to a buffer that
+ * we've already examined, we will deadlock due to the second buffer
+ * locking attempt.  Note however that grabbing a buffer in transaction
+ * context links the locked buffer to the transaction.  If we try to
+ * re-grab the buffer in the context of the same transaction, we avoid
+ * the second lock attempt and continue.  Between the verifier and the
+ * scrubber, something will notice that something is amiss and report
+ * the corruption.  Therefore, each scrubber will allocate an empty
+ * transaction, attach buffers to it, and cancel the transaction at the
+ * end of the scrub run.  Cancelling a non-dirty transaction simply
+ * unlocks the buffers.
+ *
+ * There are four pieces of data that scrub can communicate to
+ * userspace.  The first is the error code (errno), which can be used to
+ * communicate operational errors in performing the scrub.  There are
+ * also three flags that can be set in the scrub context.  If the data
+ * structure itself is corrupt, the CORRUPT flag will be set.  If
+ * the metadata is correct but otherwise suboptimal, the PREEN flag
+ * will be set.
+ */
+
+/*
+ * Scrub probe -- userspace uses this to probe if we're willing to scrub
+ * or repair a given mountpoint.  This will be used by xfs_scrub to
+ * probe the kernel's abilities to scrub (and repair) the metadata.  We
+ * do this by validating the ioctl inputs from userspace, preparing the
+ * filesystem for a scrub (or a repair) operation, and immediately
+ * returning to userspace.  Userspace can use the returned errno and
+ * structure state to decide (in broad terms) if scrub/repair are
+ * supported by the running kernel.
+ */
+static int
+xfs_scrub_probe(
+	struct xfs_scrub_context	*sc)
+{
+	int				error = 0;
+
+	if (sc->sm->sm_ino || sc->sm->sm_agno)
+		return -EINVAL;
+	if (xfs_scrub_should_terminate(sc, &error))
+		return error;
+
+	return 0;
+}
+
+/* Scrub setup and teardown */
+
+/* Free all the resources and finish the transactions. */
+STATIC int
+xfs_scrub_teardown(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip_in,
+	int				error)
+{
+	xfs_scrub_ag_free(sc, &sc->sa);
+	if (sc->tp) {
+		xfs_trans_cancel(sc->tp);
+		sc->tp = NULL;
+	}
+	if (sc->ip) {
+		xfs_iunlock(sc->ip, sc->ilock_flags);
+		if (sc->ip != ip_in &&
+		    !xfs_internal_inum(sc->mp, sc->ip->i_ino))
+			iput(VFS_I(sc->ip));
+		sc->ip = NULL;
+	}
+	if (sc->buf) {
+		kmem_free(sc->buf);
+		sc->buf = NULL;
+	}
+	return error;
+}
+
+/* Scrubbing dispatch. */
+
+static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
+	{ /* ioctl presence test */
+		.setup	= xfs_scrub_setup_fs,
+		.scrub	= xfs_scrub_probe,
+	},
+	{ /* superblock */
+		.setup	= xfs_scrub_setup_ag_header,
+		.scrub	= xfs_scrub_superblock,
+	},
+	{ /* agf */
+		.setup	= xfs_scrub_setup_ag_header,
+		.scrub	= xfs_scrub_agf,
+	},
+	{ /* agfl */
+		.setup	= xfs_scrub_setup_ag_header,
+		.scrub	= xfs_scrub_agfl,
+	},
+	{ /* agi */
+		.setup	= xfs_scrub_setup_ag_header,
+		.scrub	= xfs_scrub_agi,
+	},
+	{ /* bnobt */
+		.setup	= xfs_scrub_setup_ag_allocbt,
+		.scrub	= xfs_scrub_bnobt,
+	},
+	{ /* cntbt */
+		.setup	= xfs_scrub_setup_ag_allocbt,
+		.scrub	= xfs_scrub_cntbt,
+	},
+	{ /* inobt */
+		.setup	= xfs_scrub_setup_ag_iallocbt,
+		.scrub	= xfs_scrub_inobt,
+	},
+	{ /* finobt */
+		.setup	= xfs_scrub_setup_ag_iallocbt,
+		.scrub	= xfs_scrub_finobt,
+		.has	= xfs_sb_version_hasfinobt,
+	},
+	{ /* rmapbt */
+		.setup	= xfs_scrub_setup_ag_rmapbt,
+		.scrub	= xfs_scrub_rmapbt,
+		.has	= xfs_sb_version_hasrmapbt,
+	},
+	{ /* refcountbt */
+		.setup	= xfs_scrub_setup_ag_refcountbt,
+		.scrub	= xfs_scrub_refcountbt,
+		.has	= xfs_sb_version_hasreflink,
+	},
+	{ /* inode record */
+		.setup	= xfs_scrub_setup_inode,
+		.scrub	= xfs_scrub_inode,
+	},
+	{ /* inode data fork */
+		.setup	= xfs_scrub_setup_inode_bmap,
+		.scrub	= xfs_scrub_bmap_data,
+	},
+	{ /* inode attr fork */
+		.setup	= xfs_scrub_setup_inode_bmap,
+		.scrub	= xfs_scrub_bmap_attr,
+	},
+	{ /* inode CoW fork */
+		.setup	= xfs_scrub_setup_inode_bmap,
+		.scrub	= xfs_scrub_bmap_cow,
+	},
+	{ /* directory */
+		.setup	= xfs_scrub_setup_directory,
+		.scrub	= xfs_scrub_directory,
+	},
+	{ /* extended attributes */
+		.setup	= xfs_scrub_setup_xattr,
+		.scrub	= xfs_scrub_xattr,
+	},
+	{ /* symbolic link */
+		.setup	= xfs_scrub_setup_symlink,
+		.scrub	= xfs_scrub_symlink,
+	},
+	{ /* parent pointers */
+		.setup	= xfs_scrub_setup_parent,
+		.scrub	= xfs_scrub_parent,
+	},
+	{ /* realtime bitmap */
+		.setup	= xfs_scrub_setup_rt,
+		.scrub	= xfs_scrub_rtbitmap,
+		.has	= xfs_sb_version_hasrealtime,
+	},
+	{ /* realtime summary */
+		.setup	= xfs_scrub_setup_rt,
+		.scrub	= xfs_scrub_rtsummary,
+		.has	= xfs_sb_version_hasrealtime,
+	},
+	{ /* user quota */
+		.setup = xfs_scrub_setup_quota,
+		.scrub = xfs_scrub_quota,
+	},
+	{ /* group quota */
+		.setup = xfs_scrub_setup_quota,
+		.scrub = xfs_scrub_quota,
+	},
+	{ /* project quota */
+		.setup = xfs_scrub_setup_quota,
+		.scrub = xfs_scrub_quota,
+	},
+};
+
+/* This isn't a stable feature, warn once per day. */
+static inline void
+xfs_scrub_experimental_warning(
+	struct xfs_mount	*mp)
+{
+	static struct ratelimit_state scrub_warning = RATELIMIT_STATE_INIT(
+			"xfs_scrub_warning", 86400 * HZ, 1);
+	ratelimit_set_flags(&scrub_warning, RATELIMIT_MSG_ON_RELEASE);
+
+	if (__ratelimit(&scrub_warning))
+		xfs_alert(mp,
+"EXPERIMENTAL online scrub feature in use. Use at your own risk!");
+}
+
+/* Dispatch metadata scrubbing. */
+int
+xfs_scrub_metadata(
+	struct xfs_inode		*ip,
+	struct xfs_scrub_metadata	*sm)
+{
+	struct xfs_scrub_context	sc;
+	struct xfs_mount		*mp = ip->i_mount;
+	const struct xfs_scrub_meta_ops	*ops;
+	bool				try_harder = false;
+	int				error = 0;
+
+	trace_xfs_scrub_start(ip, sm, error);
+
+	/* Forbidden if we are shut down or mounted norecovery. */
+	error = -ESHUTDOWN;
+	if (XFS_FORCED_SHUTDOWN(mp))
+		goto out;
+	error = -ENOTRECOVERABLE;
+	if (mp->m_flags & XFS_MOUNT_NORECOVERY)
+		goto out;
+
+	/* Check our inputs. */
+	error = -EINVAL;
+	sm->sm_flags &= ~XFS_SCRUB_FLAGS_OUT;
+	if (sm->sm_flags & ~XFS_SCRUB_FLAGS_IN)
+		goto out;
+	if (memchr_inv(sm->sm_reserved, 0, sizeof(sm->sm_reserved)))
+		goto out;
+
+	/* Do we know about this type of metadata? */
+	error = -ENOENT;
+	if (sm->sm_type >= XFS_SCRUB_TYPE_NR)
+		goto out;
+	ops = &meta_scrub_ops[sm->sm_type];
+	if (ops->scrub == NULL)
+		goto out;
+
+	/*
+	 * We won't scrub any filesystem that doesn't have the ability
+	 * to record unwritten extents.  The option was made default in
+	 * 2003, removed from mkfs in 2007, and cannot be disabled in
+	 * v5, so if we find a filesystem without this flag it's either
+	 * really old or totally unsupported.  Avoid it either way.
+	 * We also don't support v1-v3 filesystems, which aren't
+	 * mountable.
+	 */
+	error = -EOPNOTSUPP;
+	if (!xfs_sb_version_hasextflgbit(&mp->m_sb))
+		goto out;
+
+	/* Does this fs even support this type of metadata? */
+	error = -ENOENT;
+	if (ops->has && !ops->has(&mp->m_sb))
+		goto out;
+
+	/* We don't know how to repair anything yet. */
+	error = -EOPNOTSUPP;
+	if (sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)
+		goto out;
+
+	xfs_scrub_experimental_warning(mp);
+
+retry_op:
+	/* Set up for the operation. */
+	memset(&sc, 0, sizeof(sc));
+	sc.mp = ip->i_mount;
+	sc.sm = sm;
+	sc.ops = ops;
+	sc.try_harder = try_harder;
+	sc.sa.agno = NULLAGNUMBER;
+	error = sc.ops->setup(&sc, ip);
+	if (error)
+		goto out_teardown;
+
+	/* Scrub for errors. */
+	error = sc.ops->scrub(&sc);
+	if (!try_harder && error == -EDEADLOCK) {
+		/*
+		 * Scrubbers return -EDEADLOCK to mean 'try harder'.
+		 * Tear down everything we hold, then set up again with
+		 * preparation for worst-case scenarios.
+		 */
+		error = xfs_scrub_teardown(&sc, ip, 0);
+		if (error)
+			goto out;
+		try_harder = true;
+		goto retry_op;
+	} else if (error)
+		goto out_teardown;
+
+	if (sc.sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
+			       XFS_SCRUB_OFLAG_XCORRUPT))
+		xfs_alert_ratelimited(mp, "Corruption detected during scrub.");
+
+out_teardown:
+	error = xfs_scrub_teardown(&sc, ip, error);
+out:
+	trace_xfs_scrub_done(ip, sm, error);
+	if (error == -EFSCORRUPTED || error == -EFSBADCRC) {
+		sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+		error = 0;
+	}
+	return error;
+}

fs/xfs/scrub/scrub.h

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_SCRUB_SCRUB_H__
+#define __XFS_SCRUB_SCRUB_H__
+
+struct xfs_scrub_context;
+
+struct xfs_scrub_meta_ops {
+	/* Acquire whatever resources are needed for the operation. */
+	int		(*setup)(struct xfs_scrub_context *,
+				 struct xfs_inode *);
+
+	/* Examine metadata for errors. */
+	int		(*scrub)(struct xfs_scrub_context *);
+
+	/* Decide if we even have this piece of metadata. */
+	bool		(*has)(struct xfs_sb *);
+};
+
+/* Buffer pointers and btree cursors for an entire AG. */
+struct xfs_scrub_ag {
+	xfs_agnumber_t			agno;
+
+	/* AG btree roots */
+	struct xfs_buf			*agf_bp;
+	struct xfs_buf			*agfl_bp;
+	struct xfs_buf			*agi_bp;
+
+	/* AG btrees */
+	struct xfs_btree_cur		*bno_cur;
+	struct xfs_btree_cur		*cnt_cur;
+	struct xfs_btree_cur		*ino_cur;
+	struct xfs_btree_cur		*fino_cur;
+	struct xfs_btree_cur		*rmap_cur;
+	struct xfs_btree_cur		*refc_cur;
+};
+
+struct xfs_scrub_context {
+	/* General scrub state. */
+	struct xfs_mount		*mp;
+	struct xfs_scrub_metadata	*sm;
+	const struct xfs_scrub_meta_ops	*ops;
+	struct xfs_trans		*tp;
+	struct xfs_inode		*ip;
+	void				*buf;
+	uint				ilock_flags;
+	bool				try_harder;
+
+	/* State tracking for single-AG operations. */
+	struct xfs_scrub_ag		sa;
+};
+
+/* Metadata scrubbers */
+int xfs_scrub_tester(struct xfs_scrub_context *sc);
+int xfs_scrub_superblock(struct xfs_scrub_context *sc);
+int xfs_scrub_agf(struct xfs_scrub_context *sc);
+int xfs_scrub_agfl(struct xfs_scrub_context *sc);
+int xfs_scrub_agi(struct xfs_scrub_context *sc);
+int xfs_scrub_bnobt(struct xfs_scrub_context *sc);
+int xfs_scrub_cntbt(struct xfs_scrub_context *sc);
+int xfs_scrub_inobt(struct xfs_scrub_context *sc);
+int xfs_scrub_finobt(struct xfs_scrub_context *sc);
+int xfs_scrub_rmapbt(struct xfs_scrub_context *sc);
+int xfs_scrub_refcountbt(struct xfs_scrub_context *sc);
+int xfs_scrub_inode(struct xfs_scrub_context *sc);
+int xfs_scrub_bmap_data(struct xfs_scrub_context *sc);
+int xfs_scrub_bmap_attr(struct xfs_scrub_context *sc);
+int xfs_scrub_bmap_cow(struct xfs_scrub_context *sc);
+int xfs_scrub_directory(struct xfs_scrub_context *sc);
+int xfs_scrub_xattr(struct xfs_scrub_context *sc);
+int xfs_scrub_symlink(struct xfs_scrub_context *sc);
+int xfs_scrub_parent(struct xfs_scrub_context *sc);
+#ifdef CONFIG_XFS_RT
+int xfs_scrub_rtbitmap(struct xfs_scrub_context *sc);
+int xfs_scrub_rtsummary(struct xfs_scrub_context *sc);
+#else
+static inline int
+xfs_scrub_rtbitmap(struct xfs_scrub_context *sc)
+{
+	return -ENOENT;
+}
+static inline int
+xfs_scrub_rtsummary(struct xfs_scrub_context *sc)
+{
+	return -ENOENT;
+}
+#endif
+#ifdef CONFIG_XFS_QUOTA
+int xfs_scrub_quota(struct xfs_scrub_context *sc);
+#else
+static inline int
+xfs_scrub_quota(struct xfs_scrub_context *sc)
+{
+	return -ENOENT;
+}
+#endif
+
+#endif	/* __XFS_SCRUB_SCRUB_H__ */

fs/xfs/scrub/symlink.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_inode_fork.h"
+#include "xfs_symlink.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+
+/* Set us up to scrub a symbolic link. */
+int
+xfs_scrub_setup_symlink(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	/* Allocate the buffer without the inode lock held. */
+	sc->buf = kmem_zalloc_large(XFS_SYMLINK_MAXLEN + 1, KM_SLEEP);
+	if (!sc->buf)
+		return -ENOMEM;
+
+	return xfs_scrub_setup_inode_contents(sc, ip, 0);
+}
+
+/* Symbolic links. */
+
+int
+xfs_scrub_symlink(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_inode		*ip = sc->ip;
+	struct xfs_ifork		*ifp;
+	loff_t				len;
+	int				error = 0;
+
+	if (!S_ISLNK(VFS_I(ip)->i_mode))
+		return -ENOENT;
+	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+	len = ip->i_d.di_size;
+
+	/* Plausible size? */
+	if (len > XFS_SYMLINK_MAXLEN || len <= 0) {
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+		goto out;
+	}
+
+	/* Inline symlink? */
+	if (ifp->if_flags & XFS_IFINLINE) {
+		if (len > XFS_IFORK_DSIZE(ip) ||
+		    len > strnlen(ifp->if_u1.if_data, XFS_IFORK_DSIZE(ip)))
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+		goto out;
+	}
+
+	/* Remote symlink; must read the contents. */
+	error = xfs_readlink_bmap_ilocked(sc->ip, sc->buf);
+	if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, 0, &error))
+		goto out;
+	if (strnlen(sc->buf, XFS_SYMLINK_MAXLEN) < len)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
+out:
+	return error;
+}

fs/xfs/scrub/trace.c

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_da_format.h"
+#include "xfs_defer.h"
+#include "xfs_inode.h"
+#include "xfs_btree.h"
+#include "xfs_trans.h"
+#include "xfs_bit.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+
+/* Figure out which block the btree cursor was pointing to. */
+static inline xfs_fsblock_t
+xfs_scrub_btree_cur_fsbno(
+	struct xfs_btree_cur		*cur,
+	int				level)
+{
+	if (level < cur->bc_nlevels && cur->bc_bufs[level])
+		return XFS_DADDR_TO_FSB(cur->bc_mp, cur->bc_bufs[level]->b_bn);
+	else if (level == cur->bc_nlevels - 1 &&
+		 cur->bc_flags & XFS_BTREE_LONG_PTRS)
+		return XFS_INO_TO_FSB(cur->bc_mp, cur->bc_private.b.ip->i_ino);
+	else if (!(cur->bc_flags & XFS_BTREE_LONG_PTRS))
+		return XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_private.a.agno, 0);
+	return NULLFSBLOCK;
+}
+
+/*
+ * We include this last to have the helpers above available for the trace
+ * event implementations.
+ */
+#define CREATE_TRACE_POINTS
+#include "scrub/trace.h"

fs/xfs/scrub/trace.h

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM xfs_scrub
+
+#if !defined(_TRACE_XFS_SCRUB_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_XFS_SCRUB_TRACE_H
+
+#include <linux/tracepoint.h>
+#include "xfs_bit.h"
+
+DECLARE_EVENT_CLASS(xfs_scrub_class,
+	TP_PROTO(struct xfs_inode *ip, struct xfs_scrub_metadata *sm,
+		 int error),
+	TP_ARGS(ip, sm, error),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(unsigned int, type)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_ino_t, inum)
+		__field(unsigned int, gen)
+		__field(unsigned int, flags)
+		__field(int, error)
+	),
+	TP_fast_assign(
+		__entry->dev = ip->i_mount->m_super->s_dev;
+		__entry->ino = ip->i_ino;
+		__entry->type = sm->sm_type;
+		__entry->agno = sm->sm_agno;
+		__entry->inum = sm->sm_ino;
+		__entry->gen = sm->sm_gen;
+		__entry->flags = sm->sm_flags;
+		__entry->error = error;
+	),
+	TP_printk("dev %d:%d ino %llu type %u agno %u inum %llu gen %u flags 0x%x error %d",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __entry->type,
+		  __entry->agno,
+		  __entry->inum,
+		  __entry->gen,
+		  __entry->flags,
+		  __entry->error)
+)
+#define DEFINE_SCRUB_EVENT(name) \
+DEFINE_EVENT(xfs_scrub_class, name, \
+	TP_PROTO(struct xfs_inode *ip, struct xfs_scrub_metadata *sm, \
+		 int error), \
+	TP_ARGS(ip, sm, error))
+
+DEFINE_SCRUB_EVENT(xfs_scrub_start);
+DEFINE_SCRUB_EVENT(xfs_scrub_done);
+DEFINE_SCRUB_EVENT(xfs_scrub_deadlock_retry);
+
+TRACE_EVENT(xfs_scrub_op_error,
+	TP_PROTO(struct xfs_scrub_context *sc, xfs_agnumber_t agno,
+		 xfs_agblock_t bno, int error, void *ret_ip),
+	TP_ARGS(sc, agno, bno, error, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(unsigned int, type)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, bno)
+		__field(int, error)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->type = sc->sm->sm_type;
+		__entry->agno = agno;
+		__entry->bno = bno;
+		__entry->error = error;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d type %u agno %u agbno %u error %d ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->type,
+		  __entry->agno,
+		  __entry->bno,
+		  __entry->error,
+		  __entry->ret_ip)
+);
+
+TRACE_EVENT(xfs_scrub_file_op_error,
+	TP_PROTO(struct xfs_scrub_context *sc, int whichfork,
+		 xfs_fileoff_t offset, int error, void *ret_ip),
+	TP_ARGS(sc, whichfork, offset, error, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(int, whichfork)
+		__field(unsigned int, type)
+		__field(xfs_fileoff_t, offset)
+		__field(int, error)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		__entry->dev = sc->ip->i_mount->m_super->s_dev;
+		__entry->ino = sc->ip->i_ino;
+		__entry->whichfork = whichfork;
+		__entry->type = sc->sm->sm_type;
+		__entry->offset = offset;
+		__entry->error = error;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d ino %llu fork %d type %u offset %llu error %d ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __entry->whichfork,
+		  __entry->type,
+		  __entry->offset,
+		  __entry->error,
+		  __entry->ret_ip)
+);
+
+DECLARE_EVENT_CLASS(xfs_scrub_block_error_class,
+	TP_PROTO(struct xfs_scrub_context *sc, xfs_daddr_t daddr, void *ret_ip),
+	TP_ARGS(sc, daddr, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(unsigned int, type)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, bno)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		xfs_fsblock_t	fsbno;
+		xfs_agnumber_t	agno;
+		xfs_agblock_t	bno;
+
+		fsbno = XFS_DADDR_TO_FSB(sc->mp, daddr);
+		agno = XFS_FSB_TO_AGNO(sc->mp, fsbno);
+		bno = XFS_FSB_TO_AGBNO(sc->mp, fsbno);
+
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->type = sc->sm->sm_type;
+		__entry->agno = agno;
+		__entry->bno = bno;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d type %u agno %u agbno %u ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->type,
+		  __entry->agno,
+		  __entry->bno,
+		  __entry->ret_ip)
+)
+
+#define DEFINE_SCRUB_BLOCK_ERROR_EVENT(name) \
+DEFINE_EVENT(xfs_scrub_block_error_class, name, \
+	TP_PROTO(struct xfs_scrub_context *sc, xfs_daddr_t daddr, \
+		 void *ret_ip), \
+	TP_ARGS(sc, daddr, ret_ip))
+
+DEFINE_SCRUB_BLOCK_ERROR_EVENT(xfs_scrub_block_error);
+DEFINE_SCRUB_BLOCK_ERROR_EVENT(xfs_scrub_block_preen);
+
+DECLARE_EVENT_CLASS(xfs_scrub_ino_error_class,
+	TP_PROTO(struct xfs_scrub_context *sc, xfs_ino_t ino, xfs_daddr_t daddr,
+		 void *ret_ip),
+	TP_ARGS(sc, ino, daddr, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(unsigned int, type)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, bno)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		xfs_fsblock_t	fsbno;
+		xfs_agnumber_t	agno;
+		xfs_agblock_t	bno;
+
+		if (daddr) {
+			fsbno = XFS_DADDR_TO_FSB(sc->mp, daddr);
+			agno = XFS_FSB_TO_AGNO(sc->mp, fsbno);
+			bno = XFS_FSB_TO_AGBNO(sc->mp, fsbno);
+		} else {
+			agno = XFS_INO_TO_AGNO(sc->mp, ino);
+			bno = XFS_AGINO_TO_AGBNO(sc->mp,
+					XFS_INO_TO_AGINO(sc->mp, ino));
+		}
+
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->ino = ino;
+		__entry->type = sc->sm->sm_type;
+		__entry->agno = agno;
+		__entry->bno = bno;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d ino %llu type %u agno %u agbno %u ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __entry->type,
+		  __entry->agno,
+		  __entry->bno,
+		  __entry->ret_ip)
+)
+
+#define DEFINE_SCRUB_INO_ERROR_EVENT(name) \
+DEFINE_EVENT(xfs_scrub_ino_error_class, name, \
+	TP_PROTO(struct xfs_scrub_context *sc, xfs_ino_t ino, \
+		 xfs_daddr_t daddr, void *ret_ip), \
+	TP_ARGS(sc, ino, daddr, ret_ip))
+
+DEFINE_SCRUB_INO_ERROR_EVENT(xfs_scrub_ino_error);
+DEFINE_SCRUB_INO_ERROR_EVENT(xfs_scrub_ino_preen);
+DEFINE_SCRUB_INO_ERROR_EVENT(xfs_scrub_ino_warning);
+
+DECLARE_EVENT_CLASS(xfs_scrub_fblock_error_class,
+	TP_PROTO(struct xfs_scrub_context *sc, int whichfork,
+		 xfs_fileoff_t offset, void *ret_ip),
+	TP_ARGS(sc, whichfork, offset, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(int, whichfork)
+		__field(unsigned int, type)
+		__field(xfs_fileoff_t, offset)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		__entry->dev = sc->ip->i_mount->m_super->s_dev;
+		__entry->ino = sc->ip->i_ino;
+		__entry->whichfork = whichfork;
+		__entry->type = sc->sm->sm_type;
+		__entry->offset = offset;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d ino %llu fork %d type %u offset %llu ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __entry->whichfork,
+		  __entry->type,
+		  __entry->offset,
+		  __entry->ret_ip)
+);
+
+#define DEFINE_SCRUB_FBLOCK_ERROR_EVENT(name) \
+DEFINE_EVENT(xfs_scrub_fblock_error_class, name, \
+	TP_PROTO(struct xfs_scrub_context *sc, int whichfork, \
+		 xfs_fileoff_t offset, void *ret_ip), \
+	TP_ARGS(sc, whichfork, offset, ret_ip))
+
+DEFINE_SCRUB_FBLOCK_ERROR_EVENT(xfs_scrub_fblock_error);
+DEFINE_SCRUB_FBLOCK_ERROR_EVENT(xfs_scrub_fblock_warning);
+
+TRACE_EVENT(xfs_scrub_incomplete,
+	TP_PROTO(struct xfs_scrub_context *sc, void *ret_ip),
+	TP_ARGS(sc, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(unsigned int, type)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->type = sc->sm->sm_type;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d type %u ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->type,
+		  __entry->ret_ip)
+);
+
+TRACE_EVENT(xfs_scrub_btree_op_error,
+	TP_PROTO(struct xfs_scrub_context *sc, struct xfs_btree_cur *cur,
+		 int level, int error, void *ret_ip),
+	TP_ARGS(sc, cur, level, error, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(unsigned int, type)
+		__field(xfs_btnum_t, btnum)
+		__field(int, level)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, bno)
+		__field(int, ptr);
+		__field(int, error)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		xfs_fsblock_t fsbno = xfs_scrub_btree_cur_fsbno(cur, level);
+
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->type = sc->sm->sm_type;
+		__entry->btnum = cur->bc_btnum;
+		__entry->level = level;
+		__entry->agno = XFS_FSB_TO_AGNO(cur->bc_mp, fsbno);
+		__entry->bno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
+		__entry->ptr = cur->bc_ptrs[level];
+		__entry->error = error;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d type %u btnum %d level %d ptr %d agno %u agbno %u error %d ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->type,
+		  __entry->btnum,
+		  __entry->level,
+		  __entry->ptr,
+		  __entry->agno,
+		  __entry->bno,
+		  __entry->error,
+		  __entry->ret_ip)
+);
+
+TRACE_EVENT(xfs_scrub_ifork_btree_op_error,
+	TP_PROTO(struct xfs_scrub_context *sc, struct xfs_btree_cur *cur,
+		 int level, int error, void *ret_ip),
+	TP_ARGS(sc, cur, level, error, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(int, whichfork)
+		__field(unsigned int, type)
+		__field(xfs_btnum_t, btnum)
+		__field(int, level)
+		__field(int, ptr)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, bno)
+		__field(int, error)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		xfs_fsblock_t fsbno = xfs_scrub_btree_cur_fsbno(cur, level);
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->ino = sc->ip->i_ino;
+		__entry->whichfork = cur->bc_private.b.whichfork;
+		__entry->type = sc->sm->sm_type;
+		__entry->btnum = cur->bc_btnum;
+		__entry->level = level;
+		__entry->ptr = cur->bc_ptrs[level];
+		__entry->agno = XFS_FSB_TO_AGNO(cur->bc_mp, fsbno);
+		__entry->bno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
+		__entry->error = error;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d ino %llu fork %d type %u btnum %d level %d ptr %d agno %u agbno %u error %d ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __entry->whichfork,
+		  __entry->type,
+		  __entry->btnum,
+		  __entry->level,
+		  __entry->ptr,
+		  __entry->agno,
+		  __entry->bno,
+		  __entry->error,
+		  __entry->ret_ip)
+);
+
+TRACE_EVENT(xfs_scrub_btree_error,
+	TP_PROTO(struct xfs_scrub_context *sc, struct xfs_btree_cur *cur,
+		 int level, void *ret_ip),
+	TP_ARGS(sc, cur, level, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(unsigned int, type)
+		__field(xfs_btnum_t, btnum)
+		__field(int, level)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, bno)
+		__field(int, ptr);
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		xfs_fsblock_t fsbno = xfs_scrub_btree_cur_fsbno(cur, level);
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->type = sc->sm->sm_type;
+		__entry->btnum = cur->bc_btnum;
+		__entry->level = level;
+		__entry->agno = XFS_FSB_TO_AGNO(cur->bc_mp, fsbno);
+		__entry->bno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
+		__entry->ptr = cur->bc_ptrs[level];
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d type %u btnum %d level %d ptr %d agno %u agbno %u ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->type,
+		  __entry->btnum,
+		  __entry->level,
+		  __entry->ptr,
+		  __entry->agno,
+		  __entry->bno,
+		  __entry->ret_ip)
+);
+
+TRACE_EVENT(xfs_scrub_ifork_btree_error,
+	TP_PROTO(struct xfs_scrub_context *sc, struct xfs_btree_cur *cur,
+		 int level, void *ret_ip),
+	TP_ARGS(sc, cur, level, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_ino_t, ino)
+		__field(int, whichfork)
+		__field(unsigned int, type)
+		__field(xfs_btnum_t, btnum)
+		__field(int, level)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, bno)
+		__field(int, ptr);
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		xfs_fsblock_t fsbno = xfs_scrub_btree_cur_fsbno(cur, level);
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->ino = sc->ip->i_ino;
+		__entry->whichfork = cur->bc_private.b.whichfork;
+		__entry->type = sc->sm->sm_type;
+		__entry->btnum = cur->bc_btnum;
+		__entry->level = level;
+		__entry->agno = XFS_FSB_TO_AGNO(cur->bc_mp, fsbno);
+		__entry->bno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
+		__entry->ptr = cur->bc_ptrs[level];
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d ino %llu fork %d type %u btnum %d level %d ptr %d agno %u agbno %u ret_ip %pF",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->ino,
+		  __entry->whichfork,
+		  __entry->type,
+		  __entry->btnum,
+		  __entry->level,
+		  __entry->ptr,
+		  __entry->agno,
+		  __entry->bno,
+		  __entry->ret_ip)
+);
+
+DECLARE_EVENT_CLASS(xfs_scrub_sbtree_class,
+	TP_PROTO(struct xfs_scrub_context *sc, struct xfs_btree_cur *cur,
+		 int level),
+	TP_ARGS(sc, cur, level),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(int, type)
+		__field(xfs_btnum_t, btnum)
+		__field(xfs_agnumber_t, agno)
+		__field(xfs_agblock_t, bno)
+		__field(int, level)
+		__field(int, nlevels)
+		__field(int, ptr)
+	),
+	TP_fast_assign(
+		xfs_fsblock_t fsbno = xfs_scrub_btree_cur_fsbno(cur, level);
+
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->type = sc->sm->sm_type;
+		__entry->btnum = cur->bc_btnum;
+		__entry->agno = XFS_FSB_TO_AGNO(cur->bc_mp, fsbno);
+		__entry->bno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
+		__entry->level = level;
+		__entry->nlevels = cur->bc_nlevels;
+		__entry->ptr = cur->bc_ptrs[level];
+	),
+	TP_printk("dev %d:%d type %u btnum %d agno %u agbno %u level %d nlevels %d ptr %d",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->type,
+		  __entry->btnum,
+		  __entry->agno,
+		  __entry->bno,
+		  __entry->level,
+		  __entry->nlevels,
+		  __entry->ptr)
+)
+#define DEFINE_SCRUB_SBTREE_EVENT(name) \
+DEFINE_EVENT(xfs_scrub_sbtree_class, name, \
+	TP_PROTO(struct xfs_scrub_context *sc, struct xfs_btree_cur *cur, \
+		 int level), \
+	TP_ARGS(sc, cur, level))
+
+DEFINE_SCRUB_SBTREE_EVENT(xfs_scrub_btree_rec);
+DEFINE_SCRUB_SBTREE_EVENT(xfs_scrub_btree_key);
+
+#endif /* _TRACE_XFS_SCRUB_TRACE_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#define TRACE_INCLUDE_FILE scrub/trace
+#include <trace/define_trace.h>

fs/xfs/scrub/xfs_scrub.h

···
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_SCRUB_H__
+#define __XFS_SCRUB_H__
+
+#ifndef CONFIG_XFS_ONLINE_SCRUB
+# define xfs_scrub_metadata(ip, sm)	(-ENOTTY)
+#else
+int xfs_scrub_metadata(struct xfs_inode *ip, struct xfs_scrub_metadata *sm);
+#endif /* CONFIG_XFS_ONLINE_SCRUB */
+
+#endif	/* __XFS_SCRUB_H__ */

fs/xfs/xfs.h

···
 #define __XFS_H__
 
 #ifdef CONFIG_XFS_DEBUG
-#define STATIC
 #define DEBUG 1
 #define XFS_BUF_LOCK_TRACKING 1
 #endif

fs/xfs/xfs_attr.h

···
 #define ATTR_KERNOTIME	0x1000	/* [kernel] don't update inode timestamps */
 #define ATTR_KERNOVAL	0x2000	/* [kernel] get attr size only, not value */
 
+#define ATTR_INCOMPLETE	0x4000	/* [kernel] return INCOMPLETE attr keys */
+
 #define XFS_ATTR_FLAGS \
 	{ ATTR_DONTFOLLOW, 	"DONTFOLLOW" }, \
 	{ ATTR_ROOT,		"ROOT" }, \
···
 	{ ATTR_CREATE,		"CREATE" }, \
 	{ ATTR_REPLACE,		"REPLACE" }, \
 	{ ATTR_KERNOTIME,	"KERNOTIME" }, \
-	{ ATTR_KERNOVAL,	"KERNOVAL" }
+	{ ATTR_KERNOVAL,	"KERNOVAL" }, \
+	{ ATTR_INCOMPLETE,	"INCOMPLETE" }
 
 /*
  * The maximum size (into the kernel or returned from the kernel) of an

fs/xfs/xfs_attr_inactive.c

···
 		 * traversal of the tree so we may deal with many blocks
 		 * before we come back to this one.
 		 */
-		error = xfs_da3_node_read(*trans, dp, child_fsb, -2, &child_bp,
-						XFS_ATTR_FORK);
+		error = xfs_da3_node_read(*trans, dp, child_fsb, -1, &child_bp,
+					  XFS_ATTR_FORK);
 		if (error)
 			return error;
-		if (child_bp) {
-						/* save for re-read later */
-			child_blkno = XFS_BUF_ADDR(child_bp);
 
-			/*
-			 * Invalidate the subtree, however we have to.
-			 */
-			info = child_bp->b_addr;
-			switch (info->magic) {
-			case cpu_to_be16(XFS_DA_NODE_MAGIC):
-			case cpu_to_be16(XFS_DA3_NODE_MAGIC):
-				error = xfs_attr3_node_inactive(trans, dp,
-							child_bp, level + 1);
-				break;
-			case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
-			case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
-				error = xfs_attr3_leaf_inactive(trans, dp,
-							child_bp);
-				break;
-			default:
-				error = -EIO;
-				xfs_trans_brelse(*trans, child_bp);
-				break;
-			}
-			if (error)
-				return error;
+		/* save for re-read later */
+		child_blkno = XFS_BUF_ADDR(child_bp);
 
-			/*
-			 * Remove the subsidiary block from the cache
-			 * and from the log.
-			 */
-			error = xfs_da_get_buf(*trans, dp, 0, child_blkno,
-				&child_bp, XFS_ATTR_FORK);
-			if (error)
-				return error;
-			xfs_trans_binval(*trans, child_bp);
+		/*
+		 * Invalidate the subtree, however we have to.
+		 */
+		info = child_bp->b_addr;
+		switch (info->magic) {
+		case cpu_to_be16(XFS_DA_NODE_MAGIC):
+		case cpu_to_be16(XFS_DA3_NODE_MAGIC):
+			error = xfs_attr3_node_inactive(trans, dp, child_bp,
+							level + 1);
+			break;
+		case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
+		case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
+			error = xfs_attr3_leaf_inactive(trans, dp, child_bp);
+			break;
+		default:
+			error = -EIO;
+			xfs_trans_brelse(*trans, child_bp);
+			break;
 		}
+		if (error)
+			return error;
+
+		/*
+		 * Remove the subsidiary block from the cache and from the log.
+		 */
+		error = xfs_da_get_buf(*trans, dp, 0, child_blkno, &child_bp,
+				       XFS_ATTR_FORK);
+		if (error)
+			return error;
+		xfs_trans_binval(*trans, child_bp);
 
 		/*
 		 * If we're not done, re-read the parent to get the next

fs/xfs/xfs_attr_list.c

···
 	return 0;
 }
 
+/*
+ * We didn't find the block & hash mentioned in the cursor state, so
+ * walk down the attr btree looking for the hash.
+ */
 STATIC int
-xfs_attr_node_list(xfs_attr_list_context_t *context)
+xfs_attr_node_list_lookup(
+	struct xfs_attr_list_context	*context,
+	struct attrlist_cursor_kern	*cursor,
+	struct xfs_buf			**pbp)
 {
-	attrlist_cursor_kern_t *cursor;
-	xfs_attr_leafblock_t *leaf;
-	xfs_da_intnode_t *node;
-	struct xfs_attr3_icleaf_hdr leafhdr;
-	struct xfs_da3_icnode_hdr nodehdr;
-	struct xfs_da_node_entry *btree;
-	int error, i;
-	struct xfs_buf *bp;
-	struct xfs_inode	*dp = context->dp;
-	struct xfs_mount	*mp = dp->i_mount;
+	struct xfs_da3_icnode_hdr	nodehdr;
+	struct xfs_da_intnode		*node;
+	struct xfs_da_node_entry	*btree;
+	struct xfs_inode		*dp = context->dp;
+	struct xfs_mount		*mp = dp->i_mount;
+	struct xfs_trans		*tp = context->tp;
+	struct xfs_buf			*bp;
+	int				i;
+	int				error = 0;
+	unsigned int			expected_level = 0;
+	uint16_t			magic;
+
+	ASSERT(*pbp == NULL);
+	cursor->blkno = 0;
+	for (;;) {
+		error = xfs_da3_node_read(tp, dp, cursor->blkno, -1, &bp,
+				XFS_ATTR_FORK);
+		if (error)
+			return error;
+		node = bp->b_addr;
+		magic = be16_to_cpu(node->hdr.info.magic);
+		if (magic == XFS_ATTR_LEAF_MAGIC ||
+		    magic == XFS_ATTR3_LEAF_MAGIC)
+			break;
+		if (magic != XFS_DA_NODE_MAGIC &&
+		    magic != XFS_DA3_NODE_MAGIC) {
+			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
+					node);
+			goto out_corruptbuf;
+		}
+
+		dp->d_ops->node_hdr_from_disk(&nodehdr, node);
+
+		/* Tree taller than we can handle; bail out! */
+		if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH)
+			goto out_corruptbuf;
+
+		/* Check the level from the root node. */
+		if (cursor->blkno == 0)
+			expected_level = nodehdr.level - 1;
+		else if (expected_level != nodehdr.level)
+			goto out_corruptbuf;
+		else
+			expected_level--;
+
+		btree = dp->d_ops->node_tree_p(node);
+		for (i = 0; i < nodehdr.count; btree++, i++) {
+			if (cursor->hashval <= be32_to_cpu(btree->hashval)) {
+				cursor->blkno = be32_to_cpu(btree->before);
+				trace_xfs_attr_list_node_descend(context,
+						btree);
+				break;
+			}
+		}
+		xfs_trans_brelse(tp, bp);
+
+		if (i == nodehdr.count)
+			return 0;
+
+		/* We can't point back to the root. */
+		if (cursor->blkno == 0)
+			return -EFSCORRUPTED;
+	}
+
+	if (expected_level != 0)
+		goto out_corruptbuf;
+
+	*pbp = bp;
+	return 0;
+
+out_corruptbuf:
+	xfs_trans_brelse(tp, bp);
+	return -EFSCORRUPTED;
+}
+
+STATIC int
+xfs_attr_node_list(
+	struct xfs_attr_list_context	*context)
+{
+	struct xfs_attr3_icleaf_hdr	leafhdr;
+	struct attrlist_cursor_kern	*cursor;
+	struct xfs_attr_leafblock	*leaf;
+	struct xfs_da_intnode		*node;
+	struct xfs_buf			*bp;
+	struct xfs_inode		*dp = context->dp;
+	struct xfs_mount		*mp = dp->i_mount;
+	int				error;
 
 	trace_xfs_attr_node_list(context);
 
···
 	 * Note that start of node block is same as start of leaf block.
 	 */
 	if (bp == NULL) {
-		cursor->blkno = 0;
-		for (;;) {
-			uint16_t magic;
-
-			error = xfs_da3_node_read(context->tp, dp,
-						      cursor->blkno, -1, &bp,
-						      XFS_ATTR_FORK);
-			if (error)
-				return error;
-			node = bp->b_addr;
-			magic = be16_to_cpu(node->hdr.info.magic);
-			if (magic == XFS_ATTR_LEAF_MAGIC ||
-			    magic == XFS_ATTR3_LEAF_MAGIC)
-				break;
-			if (magic != XFS_DA_NODE_MAGIC &&
-			    magic != XFS_DA3_NODE_MAGIC) {
-				XFS_CORRUPTION_ERROR("xfs_attr_node_list(3)",
-						     XFS_ERRLEVEL_LOW,
-						     context->dp->i_mount,
-						     node);
-				xfs_trans_brelse(context->tp, bp);
-				return -EFSCORRUPTED;
-			}
-
-			dp->d_ops->node_hdr_from_disk(&nodehdr, node);
-			btree = dp->d_ops->node_tree_p(node);
-			for (i = 0; i < nodehdr.count; btree++, i++) {
-				if (cursor->hashval
-						<= be32_to_cpu(btree->hashval)) {
-					cursor->blkno = be32_to_cpu(btree->before);
-					trace_xfs_attr_list_node_descend(context,
-									 btree);
-					break;
-				}
-			}
-			if (i == nodehdr.count) {
-				xfs_trans_brelse(context->tp, bp);
-				return 0;
-			}
-			xfs_trans_brelse(context->tp, bp);
-		}
+		error = xfs_attr_node_list_lookup(context, cursor, &bp);
+		if (error || !bp)
+			return error;
 	}
 	ASSERT(bp != NULL);
 
···
 			cursor->offset = 0;
 		}
 
-		if (entry->flags & XFS_ATTR_INCOMPLETE)
+		if ((entry->flags & XFS_ATTR_INCOMPLETE) &&
+		    !(context->flags & ATTR_INCOMPLETE))
 			continue;		/* skip incomplete entries */
 
 		if (entry->flags & XFS_ATTR_LOCAL) {
···
 #define	ATTR_ENTBASESIZE		/* minimum bytes used by an attr */ \
 	(((struct attrlist_ent *) 0)->a_name - (char *) 0)
 #define	ATTR_ENTSIZE(namelen)		/* actual bytes used by an attr */ \
-	((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(u_int32_t)-1) \
-	 & ~(sizeof(u_int32_t)-1))
+	((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(uint32_t)-1) \
+	 & ~(sizeof(uint32_t)-1))
 
 /*
  * Format an attribute and copy it out to the user's buffer.
···
 		return -EINVAL;
 	if ((cursor->initted == 0) &&
 	    (cursor->hashval || cursor->blkno || cursor->offset))
+		return -EINVAL;
+
+	/* Only internal consumers can retrieve incomplete attrs. */
+	if (flags & ATTR_INCOMPLETE)
 		return -EINVAL;
 
 	/*

fs/xfs/xfs_bmap_util.c

···
 	struct xfs_ifork	*ifp,
 	xfs_filblks_t		*count)
 {
+	struct xfs_iext_cursor	icur;
 	struct xfs_bmbt_irec	got;
-	xfs_extnum_t		numrecs = 0, i = 0;
+	xfs_extnum_t		numrecs = 0;
 
-	while (xfs_iext_get_extent(ifp, i++, &got)) {
+	for_each_xfs_iext(ifp, &icur, &got) {
 		if (!isnullstartblock(got.br_startblock)) {
 			*count += got.br_blockcount;
 			numrecs++;
 		}
 	}
+
 	return numrecs;
 }
 
···
 	return 0;
 }
 
-/*
- * returns 1 for success, 0 if we failed to map the extent.
- */
-STATIC int
-xfs_getbmapx_fix_eof_hole(
-	xfs_inode_t		*ip,		/* xfs incore inode pointer */
-	int			whichfork,
-	struct getbmapx		*out,		/* output structure */
-	int			prealloced,	/* this is a file with
-						 * preallocated data space */
-	int64_t			end,		/* last block requested */
-	xfs_fsblock_t		startblock,
-	bool			moretocome)
+static int
+xfs_getbmap_report_one(
+	struct xfs_inode	*ip,
+	struct getbmapx		*bmv,
+	struct kgetbmap		*out,
+	int64_t			bmv_end,
+	struct xfs_bmbt_irec	*got)
 {
-	int64_t			fixlen;
-	xfs_mount_t		*mp;		/* file system mount point */
-	xfs_ifork_t		*ifp;		/* inode fork pointer */
-	xfs_extnum_t		lastx;		/* last extent pointer */
-	xfs_fileoff_t		fileblock;
+	struct kgetbmap		*p = out + bmv->bmv_entries;
+	bool			shared = false, trimmed = false;
+	int			error;
 
-	if (startblock == HOLESTARTBLOCK) {
-		mp = ip->i_mount;
-		out->bmv_block = -1;
-		fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
-		fixlen -= out->bmv_offset;
-		if (prealloced && out->bmv_offset + out->bmv_length == end) {
-			/* Came to hole at EOF. Trim it. */
-			if (fixlen <= 0)
-				return 0;
-			out->bmv_length = fixlen;
-		}
-	} else {
-		if (startblock == DELAYSTARTBLOCK)
-			out->bmv_block = -2;
-		else
-			out->bmv_block = xfs_fsb_to_db(ip, startblock);
-		fileblock = XFS_BB_TO_FSB(ip->i_mount, out->bmv_offset);
-		ifp = XFS_IFORK_PTR(ip, whichfork);
-		if (!moretocome &&
-		    xfs_iext_bno_to_ext(ifp, fileblock, &lastx) &&
-		   (lastx == xfs_iext_count(ifp) - 1))
-			out->bmv_oflags |= BMV_OF_LAST;
-	}
-
-	return 1;
-}
-
-/* Adjust the reported bmap around shared/unshared extent transitions. */
-STATIC int
-xfs_getbmap_adjust_shared(
-	struct xfs_inode		*ip,
-	int				whichfork,
-	struct xfs_bmbt_irec		*map,
-	struct getbmapx			*out,
-	struct xfs_bmbt_irec		*next_map)
-{
-	struct xfs_mount		*mp = ip->i_mount;
-	xfs_agnumber_t			agno;
-	xfs_agblock_t			agbno;
-	xfs_agblock_t			ebno;
-	xfs_extlen_t			elen;
-	xfs_extlen_t			nlen;
-	int				error;
-
-	next_map->br_startblock = NULLFSBLOCK;
-	next_map->br_startoff = NULLFILEOFF;
-	next_map->br_blockcount = 0;
-
-	/* Only written data blocks can be shared. */
-	if (!xfs_is_reflink_inode(ip) ||
-	    whichfork != XFS_DATA_FORK ||
-	    !xfs_bmap_is_real_extent(map))
-		return 0;
-
-	agno = XFS_FSB_TO_AGNO(mp, map->br_startblock);
-	agbno = XFS_FSB_TO_AGBNO(mp, map->br_startblock);
-	error = xfs_reflink_find_shared(mp, NULL, agno, agbno,
-			map->br_blockcount, &ebno, &elen, true);
+	error = xfs_reflink_trim_around_shared(ip, got, &shared, &trimmed);
 	if (error)
 		return error;
 
-	if (ebno == NULLAGBLOCK) {
-		/* No shared blocks at all. */
-		return 0;
-	} else if (agbno == ebno) {
+	if (isnullstartblock(got->br_startblock) ||
+	    got->br_startblock == DELAYSTARTBLOCK) {
 		/*
-		 * Shared extent at (agbno, elen).  Shrink the reported
-		 * extent length and prepare to move the start of map[i]
-		 * to agbno+elen, with the aim of (re)formatting the new
-		 * map[i] the next time through the inner loop.
+		 * Delalloc extents that start beyond EOF can occur due to
+		 * speculative EOF allocation when the delalloc extent is larger
+		 * than the largest freespace extent at conversion time.  These
+		 * extents cannot be converted by data writeback, so can exist
+		 * here even if we are not supposed to be finding delalloc
+		 * extents.
 		 */
-		out->bmv_length = XFS_FSB_TO_BB(mp, elen);
-		out->bmv_oflags |= BMV_OF_SHARED;
-		if (elen != map->br_blockcount) {
-			*next_map = *map;
-			next_map->br_startblock += elen;
-			next_map->br_startoff += elen;
-			next_map->br_blockcount -= elen;
-		}
-		map->br_blockcount -= elen;
+		if (got->br_startoff < XFS_B_TO_FSB(ip->i_mount, XFS_ISIZE(ip)))
+			ASSERT((bmv->bmv_iflags & BMV_IF_DELALLOC) != 0);
+
+		p->bmv_oflags |= BMV_OF_DELALLOC;
+		p->bmv_block = -2;
 	} else {
-		/*
-		 * There's an unshared extent (agbno, ebno - agbno)
-		 * followed by shared extent at (ebno, elen).  Shrink
-		 * the reported extent length to cover only the unshared
-		 * extent and prepare to move up the start of map[i] to
-		 * ebno, with the aim of (re)formatting the new map[i]
-		 * the next time through the inner loop.
-		 */
-		*next_map = *map;
-		nlen = ebno - agbno;
-		out->bmv_length = XFS_FSB_TO_BB(mp, nlen);
-		next_map->br_startblock += nlen;
-		next_map->br_startoff += nlen;
-		next_map->br_blockcount -= nlen;
-		map->br_blockcount -= nlen;
+		p->bmv_block = xfs_fsb_to_db(ip, got->br_startblock);
 	}
 
+	if (got->br_state == XFS_EXT_UNWRITTEN &&
+	    (bmv->bmv_iflags & BMV_IF_PREALLOC))
+		p->bmv_oflags |= BMV_OF_PREALLOC;
+
+	if (shared)
+		p->bmv_oflags |= BMV_OF_SHARED;
+
+	p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, got->br_startoff);
+	p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, got->br_blockcount);
+
+	bmv->bmv_offset = p->bmv_offset + p->bmv_length;
+	bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
+	bmv->bmv_entries++;
 	return 0;
+}
+
+static void
+xfs_getbmap_report_hole(
+	struct xfs_inode	*ip,
+	struct getbmapx		*bmv,
+	struct kgetbmap		*out,
+	int64_t			bmv_end,
+	xfs_fileoff_t		bno,
+	xfs_fileoff_t		end)
+{
+	struct kgetbmap		*p = out + bmv->bmv_entries;
+
+	if (bmv->bmv_iflags & BMV_IF_NO_HOLES)
+		return;
+
+	p->bmv_block = -1;
+	p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, bno);
+	p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, end - bno);
+
+	bmv->bmv_offset = p->bmv_offset + p->bmv_length;
+	bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
+	bmv->bmv_entries++;
+}
+
+static inline bool
+xfs_getbmap_full(
+	struct getbmapx		*bmv)
+{
+	return bmv->bmv_length == 0 || bmv->bmv_entries >= bmv->bmv_count - 1;
+}
+
+static bool
+xfs_getbmap_next_rec(
+	struct xfs_bmbt_irec	*rec,
+	xfs_fileoff_t		total_end)
+{
+	xfs_fileoff_t		end = rec->br_startoff + rec->br_blockcount;
+
+	if (end == total_end)
+		return false;
+
+	rec->br_startoff += rec->br_blockcount;
+	if (!isnullstartblock(rec->br_startblock) &&
+	    rec->br_startblock != DELAYSTARTBLOCK)
+		rec->br_startblock += rec->br_blockcount;
+	rec->br_blockcount = total_end - end;
+	return true;
 }
 
 /*
···
  */
 int						/* error code */
 xfs_getbmap(
-	xfs_inode_t		*ip,
+	struct xfs_inode	*ip,
 	struct getbmapx		*bmv,		/* user bmap structure */
-	xfs_bmap_format_t	formatter,	/* format to user */
-	void			*arg)		/* formatter arg */
+	struct kgetbmap		*out)
 {
-	int64_t			bmvend;		/* last block requested */
-	int			error = 0;	/* return value */
-	int64_t			fixlen;		/* length for -1 case */
-	int			i;		/* extent number */
-	int			lock;		/* lock state */
-	xfs_bmbt_irec_t		*map;		/* buffer for user's data */
-	xfs_mount_t		*mp;		/* file system mount point */
-	int			nex;		/* # of user extents can do */
-	int			subnex;		/* # of bmapi's can do */
-	int			nmap;		/* number of map entries */
-	struct getbmapx		*out;		/* output structure */
-	int			whichfork;	/* data or attr fork */
-	int			prealloced;	/* this is a file with
-						 * preallocated data space */
-	int			iflags;		/* interface flags */
-	int			bmapi_flags;	/* flags for xfs_bmapi */
-	int			cur_ext = 0;
-	struct xfs_bmbt_irec	inject_map;
+	struct xfs_mount	*mp = ip->i_mount;
+	int			iflags = bmv->bmv_iflags;
+	int			whichfork, lock, error = 0;
+	int64_t			bmv_end, max_len;
+	xfs_fileoff_t		bno, first_bno;
+	struct xfs_ifork	*ifp;
+	struct xfs_bmbt_irec	got, rec;
+	xfs_filblks_t		len;
+	struct xfs_iext_cursor	icur;
 
-	mp = ip->i_mount;
-	iflags = bmv->bmv_iflags;
-
+	if (bmv->bmv_iflags & ~BMV_IF_VALID)
+		return -EINVAL;
 #ifndef DEBUG
 	/* Only allow CoW fork queries if we're debugging. */
 	if (iflags & BMV_IF_COWFORK)
···
 	if ((iflags & BMV_IF_ATTRFORK) && (iflags & BMV_IF_COWFORK))
 		return -EINVAL;
 
+	if (bmv->bmv_length < -1)
+		return -EINVAL;
+	bmv->bmv_entries = 0;
+	if (bmv->bmv_length == 0)
+		return 0;
+
 	if (iflags & BMV_IF_ATTRFORK)
 		whichfork = XFS_ATTR_FORK;
 	else if (iflags & BMV_IF_COWFORK)
 		whichfork = XFS_COW_FORK;
 	else
 		whichfork = XFS_DATA_FORK;
-
-	switch (whichfork) {
-	case XFS_ATTR_FORK:
-		if (XFS_IFORK_Q(ip)) {
-			if (ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS &&
-			    ip->i_d.di_aformat != XFS_DINODE_FMT_BTREE &&
-			    ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)
-				return -EINVAL;
-		} else if (unlikely(
-			   ip->i_d.di_aformat != 0 &&
-			   ip->i_d.di_aformat != XFS_DINODE_FMT_EXTENTS)) {
-			XFS_ERROR_REPORT("xfs_getbmap", XFS_ERRLEVEL_LOW,
-					 ip->i_mount);
-			return -EFSCORRUPTED;
-		}
-
-		prealloced = 0;
-		fixlen = 1LL << 32;
-		break;
-	case XFS_COW_FORK:
-		if (ip->i_cformat != XFS_DINODE_FMT_EXTENTS)
-			return -EINVAL;
-
-		if (xfs_get_cowextsz_hint(ip)) {
-			prealloced = 1;
-			fixlen = mp->m_super->s_maxbytes;
-		} else {
-			prealloced = 0;
-			fixlen = XFS_ISIZE(ip);
-		}
-		break;
-	default:
-		/* Local format data forks report no extents. */
-		if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
-			bmv->bmv_entries = 0;
-			return 0;
-		}
-		if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
-		    ip->i_d.di_format != XFS_DINODE_FMT_BTREE)
-			return -EINVAL;
-
-		if (xfs_get_extsz_hint(ip) ||
-		    ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC|XFS_DIFLAG_APPEND)){
-			prealloced = 1;
-			fixlen = mp->m_super->s_maxbytes;
-		} else {
-			prealloced = 0;
-			fixlen = XFS_ISIZE(ip);
-		}
-		break;
-	}
-
-	if (bmv->bmv_length == -1) {
-		fixlen = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, fixlen));
-		bmv->bmv_length =
-			max_t(int64_t, fixlen - bmv->bmv_offset, 0);
-	} else if (bmv->bmv_length == 0) {
-		bmv->bmv_entries = 0;
-		return 0;
-	} else if (bmv->bmv_length < 0) {
-		return -EINVAL;
-	}
-
-	nex = bmv->bmv_count - 1;
-	if (nex <= 0)
-		return -EINVAL;
-	bmvend = bmv->bmv_offset + bmv->bmv_length;
-
-
-	if (bmv->bmv_count > ULONG_MAX / sizeof(struct getbmapx))
-		return -ENOMEM;
-	out = kmem_zalloc_large(bmv->bmv_count * sizeof(struct getbmapx), 0);
-	if (!out)
-		return -ENOMEM;
+	ifp = XFS_IFORK_PTR(ip, whichfork);
 
 	xfs_ilock(ip, XFS_IOLOCK_SHARED);
 	switch (whichfork) {
+	case XFS_ATTR_FORK:
+		if (!XFS_IFORK_Q(ip))
+			goto out_unlock_iolock;
+
+		max_len = 1LL << 32;
+		lock = xfs_ilock_attr_map_shared(ip);
+		break;
+	case XFS_COW_FORK:
+		/* No CoW fork? Just return */
+		if (!ifp)
+			goto out_unlock_iolock;
+
+		if (xfs_get_cowextsz_hint(ip))
+			max_len = mp->m_super->s_maxbytes;
+		else
+			max_len = XFS_ISIZE(ip);
+
+		lock = XFS_ILOCK_SHARED;
+		xfs_ilock(ip, lock);
+		break;
 	case XFS_DATA_FORK:
 		if (!(iflags & BMV_IF_DELALLOC) &&
 		    (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_d.di_size)) {
···
 			 */
 		}
 
+		if (xfs_get_extsz_hint(ip) ||
+		    (ip->i_d.di_flags &
+		     (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))
+			max_len = mp->m_super->s_maxbytes;
+		else
+			max_len = XFS_ISIZE(ip);
+
 		lock = xfs_ilock_data_map_shared(ip);
 		break;
-	case XFS_COW_FORK:
-		lock = XFS_ILOCK_SHARED;
-		xfs_ilock(ip, lock);
-		break;
-	case XFS_ATTR_FORK:
-		lock = xfs_ilock_attr_map_shared(ip);
-		break;
 	}
 
-	/*
-	 * Don't let nex be bigger than the number of extents
-	 * we can have assuming alternating holes and real extents.
-	 */
-	if (nex > XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1)
-		nex = XFS_IFORK_NEXTENTS(ip, whichfork) * 2 + 1;
-
-	bmapi_flags = xfs_bmapi_aflag(whichfork);
-	if (!(iflags & BMV_IF_PREALLOC))
-		bmapi_flags |= XFS_BMAPI_IGSTATE;
-
-	/*
-	 * Allocate enough space to handle "subnex" maps at a time.
-	 */
-	error = -ENOMEM;
-	subnex = 16;
-	map = kmem_alloc(subnex * sizeof(*map), KM_MAYFAIL | KM_NOFS);
-	if (!map)
+	switch (XFS_IFORK_FORMAT(ip, whichfork)) {
+	case XFS_DINODE_FMT_EXTENTS:
+	case XFS_DINODE_FMT_BTREE:
+		break;
+	case XFS_DINODE_FMT_LOCAL:
+		/* Local format inode forks report no extents. */
 		goto out_unlock_ilock;
-
-	bmv->bmv_entries = 0;
-
-	if (XFS_IFORK_NEXTENTS(ip, whichfork) == 0 &&
-	    (whichfork == XFS_ATTR_FORK || !(iflags & BMV_IF_DELALLOC))) {
-		error = 0;
-		goto out_free_map;
+	default:
+		error = -EINVAL;
+		goto out_unlock_ilock;
 	}
 
-	do {
-		nmap = (nex> subnex) ? subnex : nex;
-		error = xfs_bmapi_read(ip, XFS_BB_TO_FSBT(mp, bmv->bmv_offset),
-				       XFS_BB_TO_FSB(mp, bmv->bmv_length),
-				       map, &nmap, bmapi_flags);
+	if (bmv->bmv_length == -1) {
+		max_len = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, max_len));
+		bmv->bmv_length = max(0LL, max_len - bmv->bmv_offset);
+	}
+
+	bmv_end = bmv->bmv_offset + bmv->bmv_length;
+
+	first_bno = bno = XFS_BB_TO_FSBT(mp, bmv->bmv_offset);
+	len = XFS_BB_TO_FSB(mp, bmv->bmv_length);
+
+	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
+		error = xfs_iread_extents(NULL, ip, whichfork);
 		if (error)
-			goto out_free_map;
-		ASSERT(nmap <= subnex);
+			goto out_unlock_ilock;
+	}
 
-		for (i = 0; i < nmap && bmv->bmv_length &&
-				cur_ext < bmv->bmv_count - 1; i++) {
-			out[cur_ext].bmv_oflags = 0;
-			if (map[i].br_state == XFS_EXT_UNWRITTEN)
-				out[cur_ext].bmv_oflags |= BMV_OF_PREALLOC;
-			else if (map[i].br_startblock == DELAYSTARTBLOCK)
-				out[cur_ext].bmv_oflags |= BMV_OF_DELALLOC;
-			out[cur_ext].bmv_offset =
-				XFS_FSB_TO_BB(mp, map[i].br_startoff);
-			out[cur_ext].bmv_length =
-				XFS_FSB_TO_BB(mp, map[i].br_blockcount);
-			out[cur_ext].bmv_unused1 = 0;
-			out[cur_ext].bmv_unused2 = 0;
+	if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
+		/*
+		 * Report a whole-file hole if the delalloc flag is set to
+		 * stay compatible with the old implementation.
+		 */
+		if (iflags & BMV_IF_DELALLOC)
+			xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
+					XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
+		goto out_unlock_ilock;
+	}
 
-			/*
-			 * delayed allocation extents that start beyond EOF can
-			 * occur due to speculative EOF allocation when the
-			 * delalloc extent is larger than the largest freespace
-			 * extent at conversion time. These extents cannot be
-			 * converted by data writeback, so can exist here even
-			 * if we are not supposed to be finding delalloc
-			 * extents.
-			 */
-			if (map[i].br_startblock == DELAYSTARTBLOCK &&
-			    map[i].br_startoff < XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
-				ASSERT((iflags & BMV_IF_DELALLOC) != 0);
+	while (!xfs_getbmap_full(bmv)) {
+		xfs_trim_extent(&got, first_bno, len);
 
-                        if (map[i].br_startblock == HOLESTARTBLOCK &&
-			    whichfork == XFS_ATTR_FORK) {
-				/* came to the end of attribute fork */
-				out[cur_ext].bmv_oflags |= BMV_OF_LAST;
-				goto out_free_map;
-			}
-
-			/* Is this a shared block? */
-			error = xfs_getbmap_adjust_shared(ip, whichfork,
-					&map[i], &out[cur_ext], &inject_map);
-			if (error)
-				goto out_free_map;
-
-			if (!xfs_getbmapx_fix_eof_hole(ip, whichfork,
-					&out[cur_ext], prealloced, bmvend,
-					map[i].br_startblock,
-					inject_map.br_startblock != NULLFSBLOCK))
-				goto out_free_map;
-
-			bmv->bmv_offset =
-				out[cur_ext].bmv_offset +
-				out[cur_ext].bmv_length;
-			bmv->bmv_length =
-				max_t(int64_t, 0, bmvend - bmv->bmv_offset);
-
-			/*
-			 * In case we don't want to return the hole,
-			 * don't increase cur_ext so that we can reuse
-			 * it in the next loop.
-			 */
-			if ((iflags & BMV_IF_NO_HOLES) &&
-			    map[i].br_startblock == HOLESTARTBLOCK) {
-				memset(&out[cur_ext], 0, sizeof(out[cur_ext]));
-				continue;
-			}
-
-			/*
-			 * In order to report shared extents accurately,
-			 * we report each distinct shared/unshared part
-			 * of a single bmbt record using multiple bmap
-			 * extents.  To make that happen, we iterate the
-			 * same map array item multiple times, each
-			 * time trimming out the subextent that we just
-			 * reported.
-			 *
-			 * Because of this, we must check the out array
-			 * index (cur_ext) directly against bmv_count-1
-			 * to avoid overflows.
-			 */
-			if (inject_map.br_startblock != NULLFSBLOCK) {
-				map[i] = inject_map;
-				i--;
-			}
-			bmv->bmv_entries++;
-			cur_ext++;
+		/*
+		 * Report an entry for a hole if this extent doesn't directly
+		 * follow the previous one.
+		 */
+		if (got.br_startoff > bno) {
+			xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
+					got.br_startoff);
+			if (xfs_getbmap_full(bmv))
+				break;
 		}
-	} while (nmap && bmv->bmv_length && cur_ext < bmv->bmv_count - 1);
 
- out_free_map:
-	kmem_free(map);
- out_unlock_ilock:
-	xfs_iunlock(ip, lock);
- out_unlock_iolock:
-	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+		/*
+		 * In order to report shared extents accurately, we report each
+		 * distinct shared / unshared part of a single bmbt record with
+		 * an individual getbmapx record.
+		 */
+		bno = got.br_startoff + got.br_blockcount;
+		rec = got;
+		do {
+			error = xfs_getbmap_report_one(ip, bmv, out, bmv_end,
+					&rec);
+			if (error || xfs_getbmap_full(bmv))
+				goto out_unlock_ilock;
+		} while (xfs_getbmap_next_rec(&rec, bno));
 
-	for (i = 0; i < cur_ext; i++) {
-		/* format results & advance arg */
-		error = formatter(&arg, &out[i]);
-		if (error)
+		if (!xfs_iext_next_extent(ifp, &icur, &got)) {
+			xfs_fileoff_t	end = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
+
+			out[bmv->bmv_entries - 1].bmv_oflags |= BMV_OF_LAST;
+
+			if (whichfork != XFS_ATTR_FORK && bno < end &&
+			    !xfs_getbmap_full(bmv)) {
+				xfs_getbmap_report_hole(ip, bmv, out, bmv_end,
+						bno, end);
+			}
+			break;
+		}
+
+		if (bno >= first_bno + len)
 			break;
 	}
 
-	kmem_free(out);
+out_unlock_ilock:
+	xfs_iunlock(ip, lock);
+out_unlock_iolock:
+	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
 	return error;
 }
 
···
 
 }
 
-/*
- * @next_fsb will keep track of the extent currently undergoing shift.
- * @stop_fsb will keep track of the extent at which we have to stop.
- * If we are shifting left, we will start with block (offset + len) and
- * shift each extent till last extent.
- * If we are shifting right, we will start with last extent inside file space
- * and continue until we reach the block corresponding to offset.
- */
 static int
-xfs_shift_file_space(
-	struct xfs_inode        *ip,
-	xfs_off_t               offset,
-	xfs_off_t               len,
-	enum shift_direction	direction)
+xfs_prepare_shift(
+	struct xfs_inode	*ip,
+	loff_t			offset)
 {
-	int			done = 0;
-	struct xfs_mount	*mp = ip->i_mount;
-	struct xfs_trans	*tp;
 	int			error;
-	struct xfs_defer_ops	dfops;
-	xfs_fsblock_t		first_block;
-	xfs_fileoff_t		stop_fsb;
-	xfs_fileoff_t		next_fsb;
-	xfs_fileoff_t		shift_fsb;
-	uint			resblks;
-
-	ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT);
-
-	if (direction == SHIFT_LEFT) {
-		/*
-		 * Reserve blocks to cover potential extent merges after left
-		 * shift operations.
-		 */
-		resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
-		next_fsb = XFS_B_TO_FSB(mp, offset + len);
-		stop_fsb = XFS_B_TO_FSB(mp, VFS_I(ip)->i_size);
-	} else {
-		/*
-		 * If right shift, delegate the work of initialization of
-		 * next_fsb to xfs_bmap_shift_extent as it has ilock held.
-		 */
-		resblks = 0;
-		next_fsb = NULLFSBLOCK;
-		stop_fsb = XFS_B_TO_FSB(mp, offset);
-	}
-
-	shift_fsb = XFS_B_TO_FSB(mp, len);
 
 	/*
 	 * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
···
 	 * Writeback and invalidate cache for the remainder of the file as we're
 	 * about to shift down every extent from offset to EOF.
 	 */
-	error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
-					     offset, -1);
+	error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, offset, -1);
 	if (error)
 		return error;
 	error = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
···
 			return error;
 	}
 
-	/*
-	 * The extent shifting code works on extent granularity. So, if
-	 * stop_fsb is not the starting block of extent, we need to split
-	 * the extent at stop_fsb.
-	 */
-	if (direction == SHIFT_RIGHT) {
-		error = xfs_bmap_split_extent(ip, stop_fsb);
-		if (error)
-			return error;
-	}
-
-	while (!error && !done) {
-		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0,
-					&tp);
-		if (error)
-			break;
-
-		xfs_ilock(ip, XFS_ILOCK_EXCL);
-		error = xfs_trans_reserve_quota(tp, mp, ip->i_udquot,
-				ip->i_gdquot, ip->i_pdquot, resblks, 0,
-				XFS_QMOPT_RES_REGBLKS);
-		if (error)
-			goto out_trans_cancel;
-
-		xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
-
-		xfs_defer_init(&dfops, &first_block);
-
-		/*
-		 * We are using the write transaction in which max 2 bmbt
-		 * updates are allowed
-		 */
-		error = xfs_bmap_shift_extents(tp, ip, &next_fsb, shift_fsb,
-				&done, stop_fsb, &first_block, &dfops,
-				direction, XFS_BMAP_MAX_SHIFT_EXTENTS);
-		if (error)
-			goto out_bmap_cancel;
-
-		error = xfs_defer_finish(&tp, &dfops);
-		if (error)
-			goto out_bmap_cancel;
-
-		error = xfs_trans_commit(tp);
-	}
-
-	return error;
-
-out_bmap_cancel:
-	xfs_defer_cancel(&dfops);
-out_trans_cancel:
-	xfs_trans_cancel(tp);
-	return error;
+	return 0;
 }
 
 /*
···
 	xfs_off_t		offset,
 	xfs_off_t		len)
 {
-	int error;
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_trans	*tp;
+	int			error;
+	struct xfs_defer_ops	dfops;
+	xfs_fsblock_t		first_block;
+	xfs_fileoff_t		stop_fsb = XFS_B_TO_FSB(mp, VFS_I(ip)->i_size);
+	xfs_fileoff_t		next_fsb = XFS_B_TO_FSB(mp, offset + len);
+	xfs_fileoff_t		shift_fsb = XFS_B_TO_FSB(mp, len);
+	uint			resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
+	bool			done = false;
 
 	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+	ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
+
 	trace_xfs_collapse_file_space(ip);
 
 	error = xfs_free_file_space(ip, offset, len);
 	if (error)
 		return error;
 
-	return xfs_shift_file_space(ip, offset, len, SHIFT_LEFT);
+	error = xfs_prepare_shift(ip, offset);
+	if (error)
+		return error;
+
+	while (!error && !done) {
+		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0,
+					&tp);
+		if (error)
+			break;
+
+		xfs_ilock(ip, XFS_ILOCK_EXCL);
+		error = xfs_trans_reserve_quota(tp, mp, ip->i_udquot,
+				ip->i_gdquot, ip->i_pdquot, resblks, 0,
+				XFS_QMOPT_RES_REGBLKS);
+		if (error)
+			goto out_trans_cancel;
+		xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+
+		xfs_defer_init(&dfops, &first_block);
+		error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb,
+				&done, stop_fsb, &first_block, &dfops);
+		if (error)
+			goto out_bmap_cancel;
+
+		error = xfs_defer_finish(&tp, &dfops);
+		if (error)
+			goto out_bmap_cancel;
+		error = xfs_trans_commit(tp);
+	}
+
+	return error;
+
+out_bmap_cancel:
+	xfs_defer_cancel(&dfops);
+out_trans_cancel:
+	xfs_trans_cancel(tp);
+	return error;
 }
 
 /*
···
 	loff_t			offset,
 	loff_t			len)
 {
+	struct xfs_mount	*mp = ip->i_mount;
+	struct xfs_trans	*tp;
+	int			error;
+	struct xfs_defer_ops	dfops;
+	xfs_fsblock_t		first_block;
+	xfs_fileoff_t		stop_fsb = XFS_B_TO_FSB(mp, offset);
+	xfs_fileoff_t		next_fsb = NULLFSBLOCK;
+	xfs_fileoff_t		shift_fsb = XFS_B_TO_FSB(mp, len);
+	bool			done = false;
+
 	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+	ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
+
 	trace_xfs_insert_file_space(ip);
 
-	return xfs_shift_file_space(ip, offset, len, SHIFT_RIGHT);
+	error = xfs_prepare_shift(ip, offset);
+	if (error)
+		return error;
+
+	/*
+	 * The extent shifting code works on extent granularity. So, if stop_fsb
+	 * is not the starting block of extent, we need to split the extent at
+	 * stop_fsb.
+	 */
+	error = xfs_bmap_split_extent(ip, stop_fsb);
+	if (error)
+		return error;
+
+	while (!error && !done) {
+		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0,
+					&tp);
+		if (error)
+			break;
+
+		xfs_ilock(ip, XFS_ILOCK_EXCL);
+		xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+		xfs_defer_init(&dfops, &first_block);
+		error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb,
+				&done, stop_fsb, &first_block, &dfops);
+		if (error)
+			goto out_bmap_cancel;
+
+		error = xfs_defer_finish(&tp, &dfops);
+		if (error)
+			goto out_bmap_cancel;
+		error = xfs_trans_commit(tp);
+	}
+
+	return error;
+
+out_bmap_cancel:
+	xfs_defer_cancel(&dfops);
+	xfs_trans_cancel(tp);
+	return error;
 }
 
 /*
···
 	xfs_filblks_t		aforkblks = 0;
 	xfs_filblks_t		taforkblks = 0;
 	xfs_extnum_t		junk;
-	xfs_extnum_t		nextents;
 	uint64_t		tmp;
 	int			error;
 
···
 
 	switch (ip->i_d.di_format) {
 	case XFS_DINODE_FMT_EXTENTS:
-		/*
-		 * If the extents fit in the inode, fix the pointer.  Otherwise
-		 * it's already NULL or pointing to the extent.
-		 */
-		nextents = xfs_iext_count(&ip->i_df);
-		if (nextents <= XFS_INLINE_EXTS)
-			ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
 		(*src_log_flags) |= XFS_ILOG_DEXT;
 		break;
 	case XFS_DINODE_FMT_BTREE:
···
 
 	switch (tip->i_d.di_format) {
 	case XFS_DINODE_FMT_EXTENTS:
-		/*
-		 * If the extents fit in the inode, fix the pointer.  Otherwise
-		 * it's already NULL or pointing to the extent.
-		 */
-		nextents = xfs_iext_count(&tip->i_df);
-		if (nextents <= XFS_INLINE_EXTS)
-			tifp->if_u1.if_extents = tifp->if_u2.if_inline_ext;
 		(*target_log_flags) |= XFS_ILOG_DEXT;
 		break;
 	case XFS_DINODE_FMT_BTREE:

fs/xfs/xfs_bmap_util.h

···
 int	xfs_bmap_punch_delalloc_range(struct xfs_inode *ip,
 		xfs_fileoff_t start_fsb, xfs_fileoff_t length);
 
-/* bmap to userspace formatter - copy to user & advance pointer */
-typedef int (*xfs_bmap_format_t)(void **, struct getbmapx *);
+struct kgetbmap {
+	__s64		bmv_offset;	/* file offset of segment in blocks */
+	__s64		bmv_block;	/* starting block (64-bit daddr_t)  */
+	__s64		bmv_length;	/* length of segment, blocks	    */
+	__s32		bmv_oflags;	/* output flags */
+};
 int	xfs_getbmap(struct xfs_inode *ip, struct getbmapx *bmv,
-		xfs_bmap_format_t formatter, void *arg);
+		struct kgetbmap *out);
 
 /* functions in xfs_bmap.c that are only needed by xfs_bmap_util.c */
 int	xfs_bmap_extsize_align(struct xfs_mount *mp, struct xfs_bmbt_irec *gotp,

fs/xfs/xfs_buf.c

···
 #include "xfs_mount.h"
 #include "xfs_trace.h"
 #include "xfs_log.h"
+#include "xfs_errortag.h"
+#include "xfs_error.h"
 
 static kmem_zone_t *xfs_buf_zone;
 
···
 xfs_buf_terminate(void)
 {
 	kmem_zone_destroy(xfs_buf_zone);
+}
+
+void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
+{
+	/*
+	 * Set the lru reference count to 0 based on the error injection tag.
+	 * This allows userspace to disrupt buffer caching for debug/testing
+	 * purposes.
+	 */
+	if (XFS_TEST_ERROR(false, bp->b_target->bt_mount,
+			   XFS_ERRTAG_BUF_LRU_REF))
+		lru_ref = 0;
+
+	atomic_set(&bp->b_lru_ref, lru_ref);
 }

fs/xfs/xfs_buf.h

···
 #define XFS_BUF_ADDR(bp)		((bp)->b_maps[0].bm_bn)
 #define XFS_BUF_SET_ADDR(bp, bno)	((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno))
 
-static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
-{
-	atomic_set(&bp->b_lru_ref, lru_ref);
-}
+void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref);
 
 static inline int xfs_buf_ispinned(struct xfs_buf *bp)
 {

fs/xfs/xfs_dir2_readdir.c

···
 	DT_FIFO, DT_SOCK, DT_LNK, DT_WHT,
 };
 
-static unsigned char
+unsigned char
 xfs_dir3_get_dtype(
 	struct xfs_mount	*mp,
 	uint8_t			filetype)
···
 	xfs_dablk_t		next_ra;
 	xfs_dablk_t		map_off;
 	xfs_dablk_t		last_da;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	icur;
 	int			ra_want;
 	int			error = 0;
 
···
 	 */
 	last_da = xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET);
 	map_off = xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, *cur_off));
-	if (!xfs_iext_lookup_extent(dp, ifp, map_off, &idx, &map))
+	if (!xfs_iext_lookup_extent(dp, ifp, map_off, &icur, &map))
 		goto out;
 	if (map.br_startoff >= last_da)
 		goto out;
···
 	if (next_ra >= last_da)
 		goto out_no_ra;
 	if (map.br_blockcount < geo->fsbcount &&
-	    !xfs_iext_get_extent(ifp, ++idx, &map))
+	    !xfs_iext_next_extent(ifp, &icur, &map))
 		goto out_no_ra;
 	if (map.br_startoff >= last_da)
 		goto out_no_ra;
···
 			ra_want -= geo->fsbcount;
 			next_ra += geo->fsbcount;
 		}
-		if (!xfs_iext_get_extent(ifp, ++idx, &map)) {
+		if (!xfs_iext_next_extent(ifp, &icur, &map)) {
 			*ra_blk = last_da;
 			break;
 		}

fs/xfs/xfs_dquot.c

···
  * otherwise by the lowest id first, see xfs_dqlock2.
  */
 
-#ifdef DEBUG
-xfs_buftarg_t *xfs_dqerror_target;
-int xfs_do_dqerror;
-int xfs_dqreq_num;
-int xfs_dqerror_mod = 33;
-#endif
-
 struct kmem_zone		*xfs_qm_dqtrxzone;
 static struct kmem_zone		*xfs_qm_dqzone;
 
···
 	xfs_dqid_t		next_id = *id + 1; /* simple advance */
 	uint			lock_flags;
 	struct xfs_bmbt_irec	got;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	cur;
 	xfs_fsblock_t		start;
 	int			error = 0;
 
···
 			return error;
 	}
 
-	if (xfs_iext_lookup_extent(quotip, &quotip->i_df, start, &idx, &got)) {
+	if (xfs_iext_lookup_extent(quotip, &quotip->i_df, start, &cur, &got)) {
 		/* contiguous chunk, bump startoff for the id calculation */
 		if (got.br_startoff < start)
 			got.br_startoff = start;
···
 		return -ESRCH;
 	}
 
-#ifdef DEBUG
-	if (xfs_do_dqerror) {
-		if ((xfs_dqerror_target == mp->m_ddev_targp) &&
-		    (xfs_dqreq_num++ % xfs_dqerror_mod) == 0) {
-			xfs_debug(mp, "Returning error in dqget");
-			return -EIO;
-		}
-	}
-
 	ASSERT(type == XFS_DQ_USER ||
 	       type == XFS_DQ_PROJ ||
 	       type == XFS_DQ_GROUP);
···
 		ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
 		ASSERT(xfs_inode_dquot(ip, type) == NULL);
 	}
-#endif
 
 restart:
 	mutex_lock(&qi->qi_tree_lock);

fs/xfs/xfs_error.c

···
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_sysfs.h"
 
···
 	XFS_RANDOM_DROP_WRITES,
 	XFS_RANDOM_LOG_BAD_CRC,
 	XFS_RANDOM_LOG_ITEM_PIN,
+	XFS_RANDOM_BUF_LRU_REF,
 };
 
 struct xfs_errortag_attr {
···
 XFS_ERRORTAG_ATTR_RW(drop_writes,	XFS_ERRTAG_DROP_WRITES);
 XFS_ERRORTAG_ATTR_RW(log_bad_crc,	XFS_ERRTAG_LOG_BAD_CRC);
 XFS_ERRORTAG_ATTR_RW(log_item_pin,	XFS_ERRTAG_LOG_ITEM_PIN);
+XFS_ERRORTAG_ATTR_RW(buf_lru_ref,	XFS_ERRTAG_BUF_LRU_REF);
 
 static struct attribute *xfs_errortag_attrs[] = {
 	XFS_ERRORTAG_ATTR_LIST(noerror),
···
 	XFS_ERRORTAG_ATTR_LIST(drop_writes),
 	XFS_ERRORTAG_ATTR_LIST(log_bad_crc),
 	XFS_ERRORTAG_ATTR_LIST(log_item_pin),
+	XFS_ERRORTAG_ATTR_LIST(buf_lru_ref),
 	NULL,
 };
 
-struct kobj_type xfs_errortag_ktype = {
+static struct kobj_type xfs_errortag_ktype = {
 	.release = xfs_sysfs_release,
 	.sysfs_ops = &xfs_errortag_sysfs_ops,
 	.default_attrs = xfs_errortag_attrs,

fs/xfs/xfs_error.h

···
 		} \
 	}
 
-/*
- * error injection tags - the labels can be anything you want
- * but each tag should have its own unique number
- */
-
-#define XFS_ERRTAG_NOERROR				0
-#define XFS_ERRTAG_IFLUSH_1				1
-#define XFS_ERRTAG_IFLUSH_2				2
-#define XFS_ERRTAG_IFLUSH_3				3
-#define XFS_ERRTAG_IFLUSH_4				4
-#define XFS_ERRTAG_IFLUSH_5				5
-#define XFS_ERRTAG_IFLUSH_6				6
-#define	XFS_ERRTAG_DA_READ_BUF				7
-#define	XFS_ERRTAG_BTREE_CHECK_LBLOCK			8
-#define	XFS_ERRTAG_BTREE_CHECK_SBLOCK			9
-#define	XFS_ERRTAG_ALLOC_READ_AGF			10
-#define	XFS_ERRTAG_IALLOC_READ_AGI			11
-#define	XFS_ERRTAG_ITOBP_INOTOBP			12
-#define	XFS_ERRTAG_IUNLINK				13
-#define	XFS_ERRTAG_IUNLINK_REMOVE			14
-#define	XFS_ERRTAG_DIR_INO_VALIDATE			15
-#define XFS_ERRTAG_BULKSTAT_READ_CHUNK			16
-#define XFS_ERRTAG_IODONE_IOERR				17
-#define XFS_ERRTAG_STRATREAD_IOERR			18
-#define XFS_ERRTAG_STRATCMPL_IOERR			19
-#define XFS_ERRTAG_DIOWRITE_IOERR			20
-#define XFS_ERRTAG_BMAPIFORMAT				21
-#define XFS_ERRTAG_FREE_EXTENT				22
-#define XFS_ERRTAG_RMAP_FINISH_ONE			23
-#define XFS_ERRTAG_REFCOUNT_CONTINUE_UPDATE		24
-#define XFS_ERRTAG_REFCOUNT_FINISH_ONE			25
-#define XFS_ERRTAG_BMAP_FINISH_ONE			26
-#define XFS_ERRTAG_AG_RESV_CRITICAL			27
-/*
- * DEBUG mode instrumentation to test and/or trigger delayed allocation
- * block killing in the event of failed writes. When enabled, all
- * buffered writes are silenty dropped and handled as if they failed.
- * All delalloc blocks in the range of the write (including pre-existing
- * delalloc blocks!) are tossed as part of the write failure error
- * handling sequence.
- */
-#define XFS_ERRTAG_DROP_WRITES				28
-#define XFS_ERRTAG_LOG_BAD_CRC				29
-#define XFS_ERRTAG_LOG_ITEM_PIN				30
-#define XFS_ERRTAG_MAX					31
-
-/*
- * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
- */
-#define XFS_RANDOM_DEFAULT				100
-#define XFS_RANDOM_IFLUSH_1				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IFLUSH_2				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IFLUSH_3				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IFLUSH_4				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IFLUSH_5				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IFLUSH_6				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_DA_READ_BUF				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_BTREE_CHECK_LBLOCK			(XFS_RANDOM_DEFAULT/4)
-#define XFS_RANDOM_BTREE_CHECK_SBLOCK			XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_ALLOC_READ_AGF			XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IALLOC_READ_AGI			XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_ITOBP_INOTOBP			XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IUNLINK				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IUNLINK_REMOVE			XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_DIR_INO_VALIDATE			XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_BULKSTAT_READ_CHUNK			XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_IODONE_IOERR				(XFS_RANDOM_DEFAULT/10)
-#define XFS_RANDOM_STRATREAD_IOERR			(XFS_RANDOM_DEFAULT/10)
-#define XFS_RANDOM_STRATCMPL_IOERR			(XFS_RANDOM_DEFAULT/10)
-#define XFS_RANDOM_DIOWRITE_IOERR			(XFS_RANDOM_DEFAULT/10)
-#define	XFS_RANDOM_BMAPIFORMAT				XFS_RANDOM_DEFAULT
-#define XFS_RANDOM_FREE_EXTENT				1
-#define XFS_RANDOM_RMAP_FINISH_ONE			1
-#define XFS_RANDOM_REFCOUNT_CONTINUE_UPDATE		1
-#define XFS_RANDOM_REFCOUNT_FINISH_ONE			1
-#define XFS_RANDOM_BMAP_FINISH_ONE			1
-#define XFS_RANDOM_AG_RESV_CRITICAL			4
-#define XFS_RANDOM_DROP_WRITES				1
-#define XFS_RANDOM_LOG_BAD_CRC				1
-#define XFS_RANDOM_LOG_ITEM_PIN				1
-
 #ifdef DEBUG
 extern int xfs_errortag_init(struct xfs_mount *mp);
 extern void xfs_errortag_del(struct xfs_mount *mp);

fs/xfs/xfs_file.c

···
 	 * point we can change the ->readdir prototype to include the
 	 * buffer size.  For now we use the current glibc buffer size.
 	 */
-	bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
+	bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_d.di_size);
 
 	return xfs_readdir(NULL, ip, ctx, bufsize);
 }

fs/xfs/xfs_icache.c

···
 	} else {
 		rcu_read_unlock();
 		if (flags & XFS_IGET_INCORE) {
-			error = -ENOENT;
+			error = -ENODATA;
 			goto out_error_or_again;
 		}
 		XFS_STATS_INC(mp, xs_ig_missed);

fs/xfs/xfs_inode.c

···
 #include "xfs_ialloc.h"
 #include "xfs_bmap.h"
 #include "xfs_bmap_util.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_quota.h"
 #include "xfs_filestream.h"
···
 }
 #endif
 
-#ifdef DEBUG
-int xfs_locked_n;
-int xfs_small_retries;
-int xfs_middle_retries;
-int xfs_lots_retries;
-int xfs_lock_delays;
-#endif
-
 /*
  * xfs_lockdep_subclass_ok() is only used in an ASSERT, so is only called when
  * DEBUG or XFS_WARN is set. And MAX_LOCKDEP_SUBCLASSES is then only defined
···
 
 		if ((attempts % 5) == 0) {
 			delay(1); /* Don't just spin the CPU */
-#ifdef DEBUG
-			xfs_lock_delays++;
-#endif
 		}
 		i = 0;
 		try_lock = 0;
 		goto again;
 	}
-
-#ifdef DEBUG
-	if (attempts) {
-		if (attempts < 5) xfs_small_retries++;
-		else if (attempts < 100) xfs_middle_retries++;
-		else xfs_lots_retries++;
-	} else {
-		xfs_locked_n++;
-	}
-#endif
 }
 
 /*
···
 	xfs_inode_t	*pip,
 	umode_t		mode,
 	xfs_nlink_t	nlink,
-	xfs_dev_t	rdev,
+	dev_t		rdev,
 	prid_t		prid,
 	int		okalloc,
 	xfs_buf_t	**ialloc_context,
···
 	set_nlink(inode, nlink);
 	ip->i_d.di_uid = xfs_kuid_to_uid(current_fsuid());
 	ip->i_d.di_gid = xfs_kgid_to_gid(current_fsgid());
+	inode->i_rdev = rdev;
 	xfs_set_projid(ip, prid);
 
 	if (pip && XFS_INHERIT_GID(pip)) {
···
 	case S_IFBLK:
 	case S_IFSOCK:
 		ip->i_d.di_format = XFS_DINODE_FMT_DEV;
-		ip->i_df.if_u2.if_rdev = rdev;
 		ip->i_df.if_flags = 0;
 		flags |= XFS_ILOG_DEV;
 		break;
···
 		ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
 		ip->i_df.if_flags = XFS_IFEXTENTS;
 		ip->i_df.if_bytes = ip->i_df.if_real_bytes = 0;
-		ip->i_df.if_u1.if_extents = NULL;
+		ip->i_df.if_u1.if_root = NULL;
 		break;
 	default:
 		ASSERT(0);
···
 					   the inode. */
 	umode_t		mode,
 	xfs_nlink_t	nlink,
-	xfs_dev_t	rdev,
+	dev_t		rdev,
 	prid_t		prid,		/* project id */
 	int		okalloc,	/* ok to allocate new space */
 	xfs_inode_t	**ipp,		/* pointer to inode; it will be
···
 	xfs_inode_t		*dp,
 	struct xfs_name		*name,
 	umode_t			mode,
-	xfs_dev_t		rdev,
+	dev_t			rdev,
 	xfs_inode_t		**ipp)
 {
 	int			is_dir = S_ISDIR(mode);
···
 		return error;
 
 	if (is_dir) {
-		rdev = 0;
 		resblks = XFS_MKDIR_SPACE_RES(mp, name->len);
 		tres = &M_RES(mp)->tr_mkdir;
 	} else {

fs/xfs/xfs_inode.h

···
 int		xfs_lookup(struct xfs_inode *dp, struct xfs_name *name,
 			   struct xfs_inode **ipp, struct xfs_name *ci_name);
 int		xfs_create(struct xfs_inode *dp, struct xfs_name *name,
-			   umode_t mode, xfs_dev_t rdev, struct xfs_inode **ipp);
+			   umode_t mode, dev_t rdev, struct xfs_inode **ipp);
 int		xfs_create_tmpfile(struct xfs_inode *dp, struct dentry *dentry,
 			   umode_t mode, struct xfs_inode **ipp);
 int		xfs_remove(struct xfs_inode *dp, struct xfs_name *name,
···
 xfs_extlen_t	xfs_get_cowextsz_hint(struct xfs_inode *ip);
 
 int		xfs_dir_ialloc(struct xfs_trans **, struct xfs_inode *, umode_t,
-			       xfs_nlink_t, xfs_dev_t, prid_t, int,
+			       xfs_nlink_t, dev_t, prid_t, int,
 			       struct xfs_inode **, int *);
 
 /* from xfs_file.c */

fs/xfs/xfs_inode_item.c

···
 		break;
 
 	case XFS_DINODE_FMT_DEV:
-	case XFS_DINODE_FMT_UUID:
 		break;
 	default:
 		ASSERT(0);
···
 	switch (ip->i_d.di_format) {
 	case XFS_DINODE_FMT_EXTENTS:
 		iip->ili_fields &=
-			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
-			  XFS_ILOG_DEV | XFS_ILOG_UUID);
+			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT | XFS_ILOG_DEV);
 
 		if ((iip->ili_fields & XFS_ILOG_DEXT) &&
 		    ip->i_d.di_nextents > 0 &&
 		    ip->i_df.if_bytes > 0) {
 			struct xfs_bmbt_rec *p;
 
-			ASSERT(ip->i_df.if_u1.if_extents != NULL);
 			ASSERT(xfs_iext_count(&ip->i_df) > 0);
 
 			p = xlog_prepare_iovec(lv, vecp, XLOG_REG_TYPE_IEXT);
···
 		break;
 	case XFS_DINODE_FMT_BTREE:
 		iip->ili_fields &=
-			~(XFS_ILOG_DDATA | XFS_ILOG_DEXT |
-			  XFS_ILOG_DEV | XFS_ILOG_UUID);
+			~(XFS_ILOG_DDATA | XFS_ILOG_DEXT | XFS_ILOG_DEV);
 
 		if ((iip->ili_fields & XFS_ILOG_DBROOT) &&
 		    ip->i_df.if_broot_bytes > 0) {
···
 		break;
 	case XFS_DINODE_FMT_LOCAL:
 		iip->ili_fields &=
-			~(XFS_ILOG_DEXT | XFS_ILOG_DBROOT |
-			  XFS_ILOG_DEV | XFS_ILOG_UUID);
+			~(XFS_ILOG_DEXT | XFS_ILOG_DBROOT | XFS_ILOG_DEV);
 		if ((iip->ili_fields & XFS_ILOG_DDATA) &&
 		    ip->i_df.if_bytes > 0) {
 			/*
···
 		break;
 	case XFS_DINODE_FMT_DEV:
 		iip->ili_fields &=
-			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
-			  XFS_ILOG_DEXT | XFS_ILOG_UUID);
+			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT | XFS_ILOG_DEXT);
 		if (iip->ili_fields & XFS_ILOG_DEV)
-			ilf->ilf_u.ilfu_rdev = ip->i_df.if_u2.if_rdev;
-		break;
-	case XFS_DINODE_FMT_UUID:
-		iip->ili_fields &=
-			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
-			  XFS_ILOG_DEXT | XFS_ILOG_DEV);
-		if (iip->ili_fields & XFS_ILOG_UUID)
-			ilf->ilf_u.ilfu_uuid = ip->i_df.if_u2.if_uuid;
+			ilf->ilf_u.ilfu_rdev = sysv_encode_dev(VFS_I(ip)->i_rdev);
 		break;
 	default:
 		ASSERT(0);
···
 
 			ASSERT(xfs_iext_count(ip->i_afp) ==
 				ip->i_d.di_anextents);
-			ASSERT(ip->i_afp->if_u1.if_extents != NULL);
 
 			p = xlog_prepare_iovec(lv, vecp, XLOG_REG_TYPE_IATTR_EXT);
 			data_bytes = xfs_iextents_copy(ip, p, XFS_ATTR_FORK);
···
 	ilf->ilf_dsize = 0;
 	ilf->ilf_asize = 0;
 	ilf->ilf_pad = 0;
-	uuid_copy(&ilf->ilf_u.ilfu_uuid, &uuid_null);
+	memset(&ilf->ilf_u, 0, sizeof(ilf->ilf_u));
 
 	xlog_finish_iovec(lv, vecp, sizeof(*ilf));
 
···
 	in_f->ilf_asize = in_f32->ilf_asize;
 	in_f->ilf_dsize = in_f32->ilf_dsize;
 	in_f->ilf_ino = in_f32->ilf_ino;
-	/* copy biggest field of ilf_u */
-	uuid_copy(&in_f->ilf_u.ilfu_uuid, &in_f32->ilf_u.ilfu_uuid);
+	memcpy(&in_f->ilf_u, &in_f32->ilf_u, sizeof(in_f->ilf_u));
 	in_f->ilf_blkno = in_f32->ilf_blkno;
 	in_f->ilf_len = in_f32->ilf_len;
 	in_f->ilf_boffset = in_f32->ilf_boffset;

fs/xfs/xfs_inode_item.h

···
 extern void xfs_istale_done(struct xfs_buf *, struct xfs_log_item *);
 extern void xfs_iflush_abort(struct xfs_inode *, bool);
 extern int xfs_inode_item_format_convert(xfs_log_iovec_t *,
-					 xfs_inode_log_format_t *);
+					 struct xfs_inode_log_format *);
 
 extern struct kmem_zone	*xfs_ili_zone;
 

fs/xfs/xfs_ioctl.c

···
 #include "xfs_btree.h"
 #include <linux/fsmap.h>
 #include "xfs_fsmap.h"
+#include "scrub/xfs_scrub.h"
 
 #include <linux/capability.h>
 #include <linux/cred.h>
···
 int
 xfs_set_dmattrs(
 	xfs_inode_t     *ip,
-	u_int		evmask,
-	u_int16_t	state)
+	uint		evmask,
+	uint16_t	state)
 {
 	xfs_mount_t	*mp = ip->i_mount;
 	xfs_trans_t	*tp;
···
  * 8. for non-realtime files, the extent size hint must be limited
  *    to half the AG size to avoid alignment extending the extent beyond the
  *    limits of the AG.
+ *
+ * Please keep this function in sync with xfs_scrub_inode_extsize.
  */
 static int
 xfs_ioctl_setattr_check_extsize(
···
  * 5. Extent size must be a multiple of the appropriate block size.
  * 6. The extent size hint must be limited to half the AG size to avoid
  *    alignment extending the extent beyond the limits of the AG.
+ *
+ * Please keep this function in sync with xfs_scrub_inode_cowextsize.
  */
 static int
 xfs_ioctl_setattr_check_cowextsize(
···
 	return error;
 }
 
-STATIC int
-xfs_getbmap_format(void **ap, struct getbmapx *bmv)
+static bool
+xfs_getbmap_format(
+	struct kgetbmap		*p,
+	struct getbmapx __user	*u,
+	size_t			recsize)
 {
-	struct getbmap __user	*base = (struct getbmap __user *)*ap;
-
-	/* copy only getbmap portion (not getbmapx) */
-	if (copy_to_user(base, bmv, sizeof(struct getbmap)))
-		return -EFAULT;
-
-	*ap += sizeof(struct getbmap);
-	return 0;
+	if (put_user(p->bmv_offset, &u->bmv_offset) ||
+	    put_user(p->bmv_block, &u->bmv_block) ||
+	    put_user(p->bmv_length, &u->bmv_length) ||
+	    put_user(0, &u->bmv_count) ||
+	    put_user(0, &u->bmv_entries))
+		return false;
+	if (recsize < sizeof(struct getbmapx))
+		return true;
+	if (put_user(0, &u->bmv_iflags) ||
+	    put_user(p->bmv_oflags, &u->bmv_oflags) ||
+	    put_user(0, &u->bmv_unused1) ||
+	    put_user(0, &u->bmv_unused2))
+		return false;
+	return true;
 }
 
 STATIC int
···
 	void			__user *arg)
 {
 	struct getbmapx		bmx = { 0 };
-	int			error;
+	struct kgetbmap		*buf;
+	size_t			recsize;
+	int			error, i;
 
-	/* struct getbmap is a strict subset of struct getbmapx. */
-	if (copy_from_user(&bmx, arg, offsetof(struct getbmapx, bmv_iflags)))
+	switch (cmd) {
+	case XFS_IOC_GETBMAPA:
+		bmx.bmv_iflags = BMV_IF_ATTRFORK;
+		/*FALLTHRU*/
+	case XFS_IOC_GETBMAP:
+		if (file->f_mode & FMODE_NOCMTIME)
+			bmx.bmv_iflags |= BMV_IF_NO_DMAPI_READ;
+		/* struct getbmap is a strict subset of struct getbmapx. */
+		recsize = sizeof(struct getbmap);
+		break;
+	case XFS_IOC_GETBMAPX:
+		recsize = sizeof(struct getbmapx);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (copy_from_user(&bmx, arg, recsize))
 		return -EFAULT;
 
 	if (bmx.bmv_count < 2)
 		return -EINVAL;
+	if (bmx.bmv_count > ULONG_MAX / recsize)
+		return -ENOMEM;
 
-	bmx.bmv_iflags = (cmd == XFS_IOC_GETBMAPA ? BMV_IF_ATTRFORK : 0);
-	if (file->f_mode & FMODE_NOCMTIME)
-		bmx.bmv_iflags |= BMV_IF_NO_DMAPI_READ;
+	buf = kmem_zalloc_large(bmx.bmv_count * sizeof(*buf), 0);
+	if (!buf)
+		return -ENOMEM;
 
-	error = xfs_getbmap(XFS_I(file_inode(file)), &bmx, xfs_getbmap_format,
-			    (__force struct getbmap *)arg+1);
+	error = xfs_getbmap(XFS_I(file_inode(file)), &bmx, buf);
 	if (error)
-		return error;
+		goto out_free_buf;
 
-	/* copy back header - only size of getbmap */
-	if (copy_to_user(arg, &bmx, sizeof(struct getbmap)))
-		return -EFAULT;
-	return 0;
-}
+	error = -EFAULT;
+	if (copy_to_user(arg, &bmx, recsize))
+		goto out_free_buf;
+	arg += recsize;
 
-STATIC int
-xfs_getbmapx_format(void **ap, struct getbmapx *bmv)
-{
-	struct getbmapx __user	*base = (struct getbmapx __user *)*ap;
+	for (i = 0; i < bmx.bmv_entries; i++) {
+		if (!xfs_getbmap_format(buf + i, arg, recsize))
+			goto out_free_buf;
+		arg += recsize;
+	}
 
-	if (copy_to_user(base, bmv, sizeof(struct getbmapx)))
-		return -EFAULT;
-
-	*ap += sizeof(struct getbmapx);
-	return 0;
-}
-
-STATIC int
-xfs_ioc_getbmapx(
-	struct xfs_inode	*ip,
-	void			__user *arg)
-{
-	struct getbmapx		bmx;
-	int			error;
-
-	if (copy_from_user(&bmx, arg, sizeof(bmx)))
-		return -EFAULT;
-
-	if (bmx.bmv_count < 2)
-		return -EINVAL;
-
-	if (bmx.bmv_iflags & (~BMV_IF_VALID))
-		return -EINVAL;
-
-	error = xfs_getbmap(ip, &bmx, xfs_getbmapx_format,
-			    (__force struct getbmapx *)arg+1);
-	if (error)
-		return error;
-
-	/* copy back header */
-	if (copy_to_user(arg, &bmx, sizeof(struct getbmapx)))
-		return -EFAULT;
-
+	error = 0;
+out_free_buf:
+	kmem_free(buf);
 	return 0;
 }
 
···
 	head.fmh_entries = xhead.fmh_entries;
 	head.fmh_oflags = xhead.fmh_oflags;
 	if (copy_to_user(arg, &head, sizeof(struct fsmap_head)))
+		return -EFAULT;
+
+	return 0;
+}
+
+STATIC int
+xfs_ioc_scrub_metadata(
+	struct xfs_inode		*ip,
+	void				__user *arg)
+{
+	struct xfs_scrub_metadata	scrub;
+	int				error;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (copy_from_user(&scrub, arg, sizeof(scrub)))
+		return -EFAULT;
+
+	error = xfs_scrub_metadata(ip, &scrub);
+	if (error)
+		return error;
+
+	if (copy_to_user(arg, &scrub, sizeof(scrub)))
 		return -EFAULT;
 
 	return 0;
···
 
 	case XFS_IOC_GETBMAP:
 	case XFS_IOC_GETBMAPA:
-		return xfs_ioc_getbmap(filp, cmd, arg);
-
 	case XFS_IOC_GETBMAPX:
-		return xfs_ioc_getbmapx(ip, arg);
+		return xfs_ioc_getbmap(filp, cmd, arg);
 
 	case FS_IOC_GETFSMAP:
 		return xfs_ioc_getfsmap(ip, arg);
+
+	case XFS_IOC_SCRUB_METADATA:
+		return xfs_ioc_scrub_metadata(ip, arg);
 
 	case XFS_IOC_FD_TO_HANDLE:
 	case XFS_IOC_PATH_TO_HANDLE:

fs/xfs/xfs_ioctl.h

···
 extern int
 xfs_set_dmattrs(
 	struct xfs_inode	*ip,
-	u_int			evmask,
-	u_int16_t		state);
+	uint			evmask,
+	uint16_t		state);
 
 #endif

fs/xfs/xfs_ioctl32.c

···
 	case XFS_IOC_ERROR_INJECTION:
 	case XFS_IOC_ERROR_CLEARALL:
 	case FS_IOC_GETFSMAP:
+	case XFS_IOC_SCRUB_METADATA:
 		return xfs_file_ioctl(filp, cmd, p);
 #ifndef BROKEN_X86_ALIGNMENT
 	/* These are handled fine if no alignment issues */

fs/xfs/xfs_iomap.c

···
 #include "xfs_bmap_btree.h"
 #include "xfs_bmap.h"
 #include "xfs_bmap_util.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_trans.h"
 #include "xfs_trans_space.h"
···
 	struct xfs_inode	*ip,
 	loff_t			offset,
 	loff_t			count,
-	xfs_extnum_t		idx)
+	struct xfs_iext_cursor	*icur)
 {
 	struct xfs_mount	*mp = ip->i_mount;
 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
···
 	 */
 	if ((mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) ||
 	    XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) ||
-	    !xfs_iext_get_extent(ifp, idx - 1, &prev) ||
+	    !xfs_iext_peek_prev_extent(ifp, icur, &prev) ||
 	    prev.br_startoff + prev.br_blockcount < offset_fsb)
 		return mp->m_writeio_blocks;
 
···
 	xfs_fileoff_t		end_fsb;
 	int			error = 0, eof = 0;
 	struct xfs_bmbt_irec	got;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	icur;
 	xfs_fsblock_t		prealloc_blocks = 0;
 
 	ASSERT(!XFS_IS_REALTIME_INODE(ip));
···
 			goto out_unlock;
 	}
 
-	eof = !xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got);
+	eof = !xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got);
 	if (!eof && got.br_startoff <= offset_fsb) {
 		if (xfs_is_reflink_inode(ip)) {
 			bool		shared;
···
 	end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
 
 	if (eof) {
-		prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count, idx);
+		prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count,
+				&icur);
 		if (prealloc_blocks) {
 			xfs_extlen_t	align;
 			xfs_off_t	end_offset;
···
 
 retry:
 	error = xfs_bmapi_reserve_delalloc(ip, XFS_DATA_FORK, offset_fsb,
-			end_fsb - offset_fsb, prealloc_blocks, &got, &idx, eof);
+			end_fsb - offset_fsb, prealloc_blocks, &got, &icur,
+			eof);
 	switch (error) {
 	case 0:
 		break;

fs/xfs/xfs_iops.c

···
 	if (S_ISCHR(mode) || S_ISBLK(mode)) {
 		if (unlikely(!sysv_valid_dev(rdev) || MAJOR(rdev) & ~0x1ff))
 			return -EINVAL;
-		rdev = sysv_encode_dev(rdev);
 	} else {
 		rdev = 0;
 	}
···
 	case S_IFBLK:
 	case S_IFCHR:
 		stat->blksize = BLKDEV_IOSIZE;
-		stat->rdev = MKDEV(sysv_major(ip->i_df.if_u2.if_rdev) & 0x1ff,
-				   sysv_minor(ip->i_df.if_u2.if_rdev));
+		stat->rdev = inode->i_rdev;
 		break;
 	default:
 		if (XFS_IS_REALTIME_INODE(ip)) {
···
 		return error;
 
 	/*
-	 * We are going to log the inode size change in this transaction so
-	 * any previous writes that are beyond the on disk EOF and the new
-	 * EOF that have not been written out need to be written here.  If we
-	 * do not write the data out, we expose ourselves to the null files
-	 * problem. Note that this includes any block zeroing we did above;
-	 * otherwise those blocks may not be zeroed after a crash.
-	 */
-	if (did_zeroing ||
-	    (newsize > ip->i_d.di_size && oldsize != ip->i_d.di_size)) {
-		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
-						      ip->i_d.di_size, newsize);
-		if (error)
-			return error;
-	}
-
-	/*
 	 * We've already locked out new page faults, so now we can safely remove
 	 * pages from the page cache knowing they won't get refaulted until we
 	 * drop the XFS_MMAP_EXCL lock after the extent manipulations are
···
 	 * user visible changes). There's not much we can do about this, except
 	 * to hope that the caller sees ENOMEM and retries the truncate
 	 * operation.
+	 *
+	 * And we update in-core i_size and truncate page cache beyond newsize
+	 * before writeback the [di_size, newsize] range, so we're guaranteed
+	 * not to write stale data past the new EOF on truncate down.
 	 */
 	truncate_setsize(inode, newsize);
+
+	/*
+	 * We are going to log the inode size change in this transaction so
+	 * any previous writes that are beyond the on disk EOF and the new
+	 * EOF that have not been written out need to be written here.  If we
+	 * do not write the data out, we expose ourselves to the null files
+	 * problem. Note that this includes any block zeroing we did above;
+	 * otherwise those blocks may not be zeroed after a crash.
+	 */
+	if (did_zeroing ||
+	    (newsize > ip->i_d.di_size && oldsize != ip->i_d.di_size)) {
+		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
+						ip->i_d.di_size, newsize - 1);
+		if (error)
+			return error;
+	}
 
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
 	if (error)
···
 
 	inode->i_uid    = xfs_uid_to_kuid(ip->i_d.di_uid);
 	inode->i_gid    = xfs_gid_to_kgid(ip->i_d.di_gid);
-
-	switch (inode->i_mode & S_IFMT) {
-	case S_IFBLK:
-	case S_IFCHR:
-		inode->i_rdev =
-			MKDEV(sysv_major(ip->i_df.if_u2.if_rdev) & 0x1ff,
-			      sysv_minor(ip->i_df.if_u2.if_rdev));
-		break;
-	default:
-		inode->i_rdev = 0;
-		break;
-	}
 
 	i_size_write(inode, ip->i_d.di_size);
 	xfs_diflags_to_iflags(inode, ip);

fs/xfs/xfs_itable.c

···
 #include "xfs_trace.h"
 #include "xfs_icache.h"
 
-int
-xfs_internal_inum(
-	xfs_mount_t	*mp,
-	xfs_ino_t	ino)
-{
-	return (ino == mp->m_sb.sb_rbmino || ino == mp->m_sb.sb_rsumino ||
-		(xfs_sb_version_hasquota(&mp->m_sb) &&
-		 xfs_is_quota_inode(&mp->m_sb, ino)));
-}
-
 /*
  * Return stat information for one inode.
  * Return 0 if ok, else errno.
···
 
 	switch (dic->di_format) {
 	case XFS_DINODE_FMT_DEV:
-		buf->bs_rdev = ip->i_df.if_u2.if_rdev;
+		buf->bs_rdev = sysv_encode_dev(inode->i_rdev);
 		buf->bs_blksize = BLKDEV_IOSIZE;
 		buf->bs_blocks = 0;
 		break;
 	case XFS_DINODE_FMT_LOCAL:
-	case XFS_DINODE_FMT_UUID:
 		buf->bs_rdev = 0;
 		buf->bs_blksize = mp->m_sb.sb_blocksize;
 		buf->bs_blocks = 0;

fs/xfs/xfs_itable.h

···
 	void			__user *buffer, /* buffer with inode info */
 	inumbers_fmt_pf		formatter);
 
-int xfs_internal_inum(struct xfs_mount *mp, xfs_ino_t ino);
-
 #endif	/* __XFS_ITABLE_H__ */

fs/xfs/xfs_linux.h

···
 #define SYNCHRONIZE()	barrier()
 #define __return_address __builtin_return_address(0)
 
+/*
+ * Return the address of a label.  Use barrier() so that the optimizer
+ * won't reorder code to refactor the error jumpouts into a single
+ * return, which throws off the reported address.
+ */
+#define __this_address	({ __label__ __here; __here: barrier(); &&__here; })
+
 #define XFS_PROJID_DEFAULT	0
 
 #define MIN(a,b)	(min(a,b))
···
 #define ASSERT(expr)	\
 	(likely(expr) ? (void)0 : assfail(#expr, __FILE__, __LINE__))
 
-#ifndef STATIC
-# define STATIC noinline
-#endif
-
 #else	/* !DEBUG */
 
 #ifdef XFS_WARN
···
 #define ASSERT(expr)	\
 	(likely(expr) ? (void)0 : asswarn(#expr, __FILE__, __LINE__))
 
-#ifndef STATIC
-# define STATIC static noinline
-#endif
-
 #else	/* !DEBUG && !XFS_WARN */
 
 #define ASSERT(expr)	((void)0)
 
-#ifndef STATIC
-# define STATIC static noinline
-#endif
-
 #endif /* XFS_WARN */
 #endif /* DEBUG */
+
+#define STATIC static noinline
 
 #ifdef CONFIG_XFS_RT
 

fs/xfs/xfs_log.c

···
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_trans.h"
 #include "xfs_trans_priv.h"
···
 	xfs_daddr_t	blk_offset,
 	int		num_bblks)
 {
+	bool		fatal = xfs_sb_version_hascrc(&mp->m_sb);
 	int		error = 0;
 	int		min_logfsbs;
 
···
 			 XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
 			 XFS_MAX_LOG_BYTES);
 		error = -EINVAL;
+	} else if (mp->m_sb.sb_logsunit > 1 &&
+		   mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) {
+		xfs_warn(mp,
+		"log stripe unit %u bytes must be a multiple of block size",
+			 mp->m_sb.sb_logsunit);
+		error = -EINVAL;
+		fatal = true;
 	}
 	if (error) {
-		if (xfs_sb_version_hascrc(&mp->m_sb)) {
+		/*
+		 * Log check errors are always fatal on v5; or whenever bad
+		 * metadata leads to a crash.
+		 */
+		if (fatal) {
 			xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
 			ASSERT(0);
 			goto out_free_log;
···
 {
 	int	error = 0;
 	bool	readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
+	bool	recovered = mp->m_log->l_flags & XLOG_RECOVERY_NEEDED;
 
 	if (mp->m_flags & XFS_MOUNT_NORECOVERY) {
 		ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
···
 		xfs_log_work_queue(mp);
 	mp->m_super->s_flags &= ~MS_ACTIVE;
 	evict_inodes(mp->m_super);
+
+	/*
+	 * Drain the buffer LRU after log recovery. This is required for v4
+	 * filesystems to avoid leaving around buffers with NULL verifier ops,
+	 * but we do it unconditionally to make sure we're always in a clean
+	 * cache state after mount.
+	 *
+	 * Don't push in the error case because the AIL may have pending intents
+	 * that aren't removed until recovery is cancelled.
+	 */
+	if (!error && recovered) {
+		xfs_log_force(mp, XFS_LOG_SYNC);
+		xfs_ail_push_all_sync(mp->m_ail);
+	}
+	xfs_wait_buftarg(mp->m_ddev_targp);
 
 	if (readonly)
 		mp->m_flags |= XFS_MOUNT_RDONLY;
···
  * one of the iclogs.  This uses backup pointers stored in a different
  * part of the log in case we trash the log structure.
  */
-void
+STATIC void
 xlog_verify_dest_ptr(
 	struct xlog	*log,
 	void		*ptr)

fs/xfs/xfs_log_recover.c

···
  */
 
 /*
- * Verify the given count of basic blocks is valid number of blocks
- * to specify for an operation involving the given XFS log buffer.
- * Returns nonzero if the count is valid, 0 otherwise.
+ * Verify the log-relative block number and length in basic blocks are valid for
+ * an operation involving the given XFS log buffer. Returns true if the fields
+ * are valid, false otherwise.
  */
-
-static inline int
-xlog_buf_bbcount_valid(
+static inline bool
+xlog_verify_bp(
 	struct xlog	*log,
+	xfs_daddr_t	blk_no,
 	int		bbcount)
 {
-	return bbcount > 0 && bbcount <= log->l_logBBsize;
+	if (blk_no < 0 || blk_no >= log->l_logBBsize)
+		return false;
+	if (bbcount <= 0 || (blk_no + bbcount) > log->l_logBBsize)
+		return false;
+	return true;
 }
 
 /*
···
 {
 	struct xfs_buf	*bp;
 
-	if (!xlog_buf_bbcount_valid(log, nbblks)) {
+	/*
+	 * Pass log block 0 since we don't have an addr yet, buffer will be
+	 * verified on read.
+	 */
+	if (!xlog_verify_bp(log, 0, nbblks)) {
 		xfs_warn(log->l_mp, "Invalid block length (0x%x) for buffer",
 			nbblks);
 		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_HIGH, log->l_mp);
···
 {
 	int		error;
 
-	if (!xlog_buf_bbcount_valid(log, nbblks)) {
-		xfs_warn(log->l_mp, "Invalid block length (0x%x) for buffer",
-			nbblks);
+	if (!xlog_verify_bp(log, blk_no, nbblks)) {
+		xfs_warn(log->l_mp,
+			 "Invalid log block/length (0x%llx, 0x%x) for buffer",
+			 blk_no, nbblks);
 		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_HIGH, log->l_mp);
 		return -EFSCORRUPTED;
 	}
···
 {
 	int		error;
 
-	if (!xlog_buf_bbcount_valid(log, nbblks)) {
-		xfs_warn(log->l_mp, "Invalid block length (0x%x) for buffer",
-			nbblks);
+	if (!xlog_verify_bp(log, blk_no, nbblks)) {
+		xfs_warn(log->l_mp,
+			 "Invalid log block/length (0x%llx, 0x%x) for buffer",
+			 blk_no, nbblks);
 		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_HIGH, log->l_mp);
 		return -EFSCORRUPTED;
 	}
···
 	 * in the in-core log.  The following number can be made tighter if
 	 * we actually look at the block size of the filesystem.
 	 */
-	num_scan_bblks = XLOG_TOTAL_REC_SHIFT(log);
+	num_scan_bblks = min_t(int, log_bbnum, XLOG_TOTAL_REC_SHIFT(log));
 	if (head_blk >= num_scan_bblks) {
 		/*
 		 * We are guaranteed that the entire check can be performed
···
 	struct xlog_recover_item	*item,
 	xfs_lsn_t			current_lsn)
 {
-	xfs_inode_log_format_t	*in_f;
+	struct xfs_inode_log_format	*in_f;
 	xfs_mount_t		*mp = log->l_mp;
 	xfs_buf_t		*bp;
 	xfs_dinode_t		*dip;
···
 	uint			isize;
 	int			need_free = 0;
 
-	if (item->ri_buf[0].i_len == sizeof(xfs_inode_log_format_t)) {
+	if (item->ri_buf[0].i_len == sizeof(struct xfs_inode_log_format)) {
 		in_f = item->ri_buf[0].i_addr;
 	} else {
-		in_f = kmem_alloc(sizeof(xfs_inode_log_format_t), KM_SLEEP);
+		in_f = kmem_alloc(sizeof(struct xfs_inode_log_format), KM_SLEEP);
 		need_free = 1;
 		error = xfs_inode_item_format_convert(&item->ri_buf[0], in_f);
 		if (error)
···
 	}
 
 	fields = in_f->ilf_fields;
-	switch (fields & (XFS_ILOG_DEV | XFS_ILOG_UUID)) {
-	case XFS_ILOG_DEV:
+	if (fields & XFS_ILOG_DEV)
 		xfs_dinode_put_rdev(dip, in_f->ilf_u.ilfu_rdev);
-		break;
-	case XFS_ILOG_UUID:
-		memcpy(XFS_DFORK_DPTR(dip),
-		       &in_f->ilf_u.ilfu_uuid,
-		       sizeof(uuid_t));
-		break;
-	}
 
 	if (in_f->ilf_size == 2)
 		goto out_owner_change;
···
 	char			*dp,
 	int			len)
 {
-	xfs_inode_log_format_t	*in_f;			/* any will do */
+	struct xfs_inode_log_format	*in_f;			/* any will do */
 	xlog_recover_item_t	*item;
 	char			*ptr;
 
···
 
 	ptr = kmem_alloc(len, KM_SLEEP);
 	memcpy(ptr, dp, len);
-	in_f = (xfs_inode_log_format_t *)ptr;
+	in_f = (struct xfs_inode_log_format *)ptr;
 
 	/* take the tail entry */
 	item = list_entry(trans->r_itemq.prev, xlog_recover_item_t, ri_list);
···
  * Read all of the agf and agi counters and check that they
  * are consistent with the superblock counters.
  */
-void
+STATIC void
 xlog_recover_check_summary(
 	struct xlog	*log)
 {

fs/xfs/xfs_mount.c

···
 	xfs_rtunmount_inodes(mp);
  out_rele_rip:
 	IRELE(rip);
-	cancel_delayed_work_sync(&mp->m_reclaim_work);
-	xfs_reclaim_inodes(mp, SYNC_WAIT);
 	/* Clean out dquots that might be in memory after quotacheck. */
 	xfs_qm_unmount(mp);
+	/*
+	 * Cancel all delayed reclaim work and reclaim the inodes directly.
+	 * We have to do this /after/ rtunmount and qm_unmount because those
+	 * two will have scheduled delayed reclaim for the rt/quota inodes.
+	 *
+	 * This is slightly different from the unmountfs call sequence
+	 * because we could be tearing down a partially set up mount.  In
+	 * particular, if log_mount_finish fails we bail out without calling
+	 * qm_unmount_quotas and therefore rely on qm_unmount to release the
+	 * quota inodes.
+	 */
+	cancel_delayed_work_sync(&mp->m_reclaim_work);
+	xfs_reclaim_inodes(mp, SYNC_WAIT);
  out_log_dealloc:
 	mp->m_flags |= XFS_MOUNT_UNMOUNTING;
 	xfs_log_mount_cancel(mp);

fs/xfs/xfs_reflink.c

···
 	struct xfs_bmbt_irec	got;
 	int			error = 0;
 	bool			eof = false, trimmed;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	icur;
 
 	/*
 	 * Search the COW fork extent list first.  This serves two purposes:
···
 	 * tree.
 	 */
 
-	if (!xfs_iext_lookup_extent(ip, ifp, imap->br_startoff, &idx, &got))
+	if (!xfs_iext_lookup_extent(ip, ifp, imap->br_startoff, &icur, &got))
 		eof = true;
 	if (!eof && got.br_startoff <= imap->br_startoff) {
 		trace_xfs_reflink_cow_found(ip, imap);
···
 		return error;
 
 	error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff,
-			imap->br_blockcount, 0, &got, &idx, eof);
+			imap->br_blockcount, 0, &got, &icur, eof);
 	if (error == -ENOSPC || error == -EDQUOT)
 		trace_xfs_reflink_cow_enospc(ip, imap);
 	if (error)
···
 	xfs_off_t		offset,
 	xfs_off_t		count)
 {
-	struct xfs_bmbt_irec	got;
-	struct xfs_defer_ops	dfops;
 	struct xfs_mount	*mp = ip->i_mount;
-	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
 	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
 	xfs_fileoff_t		end_fsb = XFS_B_TO_FSB(mp, offset + count);
-	xfs_extnum_t		idx;
-	bool			found;
-	int			error = 0;
+	xfs_filblks_t		count_fsb = end_fsb - offset_fsb;
+	struct xfs_bmbt_irec	imap;
+	struct xfs_defer_ops	dfops;
+	xfs_fsblock_t		first_block = NULLFSBLOCK;
+	int			nimaps = 1, error = 0;
+
+	ASSERT(count != 0);
 
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
-
-	/* Convert all the extents to real from unwritten. */
-	for (found = xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got);
-	     found && got.br_startoff < end_fsb;
-	     found = xfs_iext_get_extent(ifp, ++idx, &got)) {
-		error = xfs_reflink_convert_cow_extent(ip, &got, offset_fsb,
-				end_fsb - offset_fsb, &dfops);
-		if (error)
-			break;
-	}
-
-	/* Finish up. */
+	error = xfs_bmapi_write(NULL, ip, offset_fsb, count_fsb,
+			XFS_BMAPI_COWFORK | XFS_BMAPI_CONVERT |
+			XFS_BMAPI_CONVERT_ONLY, &first_block, 0, &imap, &nimaps,
+			&dfops);
 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
 	return error;
 }
···
 	bool			trimmed;
 	xfs_filblks_t		resaligned;
 	xfs_extlen_t		resblks = 0;
-	xfs_extnum_t		idx;
+	struct xfs_iext_cursor	icur;
 
 retry:
 	ASSERT(xfs_is_reflink_inode(ip));
···
 	 * Even if the extent is not shared we might have a preallocation for
 	 * it in the COW fork.  If so use it.
 	 */
-	if (xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &idx, &got) &&
+	if (xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &got) &&
 	    got.br_startoff <= offset_fsb) {
 		*shared = true;
 
···
 	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
 	xfs_fileoff_t			offset_fsb;
 	struct xfs_bmbt_irec		got;
-	xfs_extnum_t			idx;
+	struct xfs_iext_cursor		icur;
 
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
 	ASSERT(xfs_is_reflink_inode(ip));
 
 	offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
-	if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got))
+	if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got))
 		return false;
 	if (got.br_startoff > offset_fsb)
 		return false;
···
 {
 	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
 	struct xfs_bmbt_irec		got;
-	xfs_extnum_t			idx;
+	struct xfs_iext_cursor		icur;
 
 	if (!xfs_is_reflink_inode(ip))
 		return;
 
 	/* Find the extent in the CoW fork. */
-	if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got))
+	if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got))
 		return;
 
 	/* This is the extent before; try sliding up one. */
 	if (got.br_startoff < offset_fsb) {
-		if (!xfs_iext_get_extent(ifp, idx + 1, &got))
+		if (!xfs_iext_next_extent(ifp, &icur, &got))
 			return;
 	}
 
···
 {
 	struct xfs_ifork		*ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
 	struct xfs_bmbt_irec		got, del;
-	xfs_extnum_t			idx;
+	struct xfs_iext_cursor		icur;
 	xfs_fsblock_t			firstfsb;
 	struct xfs_defer_ops		dfops;
 	int				error = 0;
 
 	if (!xfs_is_reflink_inode(ip))
 		return 0;
-	if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got))
+	if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got))
 		return 0;
 
-	while (got.br_startoff < end_fsb) {
+	/* Walk backwards until we're out of the I/O range... */
+	while (got.br_startoff + got.br_blockcount > offset_fsb) {
 		del = got;
 		xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb);
+
+		/* Extent delete may have bumped ext forward */
+		if (!del.br_blockcount) {
+			xfs_iext_prev(ifp, &icur);
+			goto next_extent;
+		}
+
 		trace_xfs_reflink_cancel_cow(ip, &del);
 
 		if (isnullstartblock(del.br_startblock)) {
 			error = xfs_bmap_del_extent_delay(ip, XFS_COW_FORK,
-					&idx, &got, &del);
+					&icur, &got, &del);
 			if (error)
 				break;
 		} else if (del.br_state == XFS_EXT_UNWRITTEN || cancel_real) {
···
 			}
 
 			/* Remove the mapping from the CoW fork. */
-			xfs_bmap_del_extent_cow(ip, &idx, &got, &del);
+			xfs_bmap_del_extent_cow(ip, &icur, &got, &del);
 		}
-
-		if (!xfs_iext_get_extent(ifp, ++idx, &got))
+next_extent:
+		if (!xfs_iext_get_extent(ifp, &icur, &got))
 			break;
 	}
 
···
 	int				error;
 	unsigned int			resblks;
 	xfs_filblks_t			rlen;
-	xfs_extnum_t			idx;
+	struct xfs_iext_cursor		icur;
 
 	trace_xfs_reflink_end_cow(ip, offset, count);
 
···
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);
 
-	/* If there is a hole at end_fsb - 1 go to the previous extent */
-	if (!xfs_iext_lookup_extent(ip, ifp, end_fsb - 1, &idx, &got) ||
-	    got.br_startoff > end_fsb) {
-		/*
-		 * In case of racing, overlapping AIO writes no COW extents
-		 * might be left by the time I/O completes for the loser of
-		 * the race.  In that case we are done.
-		 */
-		if (idx <= 0)
-			goto out_cancel;
-		xfs_iext_get_extent(ifp, --idx, &got);
-	}
+	/*
+	 * In case of racing, overlapping AIO writes no COW extents might be
+	 * left by the time I/O completes for the loser of the race.  In that
+	 * case we are done.
+	 */
+	if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got))
+		goto out_cancel;
 
 	/* Walk backwards until we're out of the I/O range... */
 	while (got.br_startoff + got.br_blockcount > offset_fsb) {
 		del = got;
 		xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb);
 
-		/* Extent delete may have bumped idx forward */
+		/* Extent delete may have bumped ext forward */
 		if (!del.br_blockcount) {
-			idx--;
+			xfs_iext_prev(ifp, &icur);
 			goto next_extent;
 		}
 
···
 		 * allocated but have not yet been involved in a write.
 		 */
 		if (got.br_state == XFS_EXT_UNWRITTEN) {
-			idx--;
+			xfs_iext_prev(ifp, &icur);
 			goto next_extent;
 		}
 
···
 			goto out_defer;
 
 		/* Remove the mapping from the CoW fork. */
-		xfs_bmap_del_extent_cow(ip, &idx, &got, &del);
+		xfs_bmap_del_extent_cow(ip, &icur, &got, &del);
 
 		xfs_defer_ijoin(&dfops, ip);
 		error = xfs_defer_finish(&tp, &dfops);
 		if (error)
 			goto out_defer;
 next_extent:
-		if (!xfs_iext_get_extent(ifp, idx, &got))
+		if (!xfs_iext_get_extent(ifp, &icur, &got))
 			break;
 	}
 
···
 	xfs_extlen_t			aglen;
 	xfs_agblock_t			rbno;
 	xfs_extlen_t			rlen;
-	xfs_extnum_t			idx;
+	struct xfs_iext_cursor		icur;
 	bool				found;
 	int				error;
 
···
 	}
 
 	*has_shared = false;
-	found = xfs_iext_lookup_extent(ip, ifp, 0, &idx, &got);
+	found = xfs_iext_lookup_extent(ip, ifp, 0, &icur, &got);
 	while (found) {
 		if (isnullstartblock(got.br_startblock) ||
 		    got.br_state != XFS_EXT_NORM)
···
 			return 0;
 		}
 next:
-		found = xfs_iext_get_extent(ifp, ++idx, &got);
+		found = xfs_iext_next_extent(ifp, &icur, &got);
 	}
 
 	return 0;

fs/xfs/xfs_rtalloc.h

···
 int xfs_rtalloc_query_all(struct xfs_trans *tp,
 			  xfs_rtalloc_query_range_fn fn,
 			  void *priv);
+bool xfs_verify_rtbno(struct xfs_mount *mp, xfs_rtblock_t rtbno);
 #else
 # define xfs_rtallocate_extent(t,b,min,max,l,f,p,rb)    (ENOSYS)
 # define xfs_rtfree_extent(t,b,l)                       (ENOSYS)
···
 # define xfs_rtalloc_query_range(t,l,h,f,p)             (ENOSYS)
 # define xfs_rtalloc_query_all(t,f,p)                   (ENOSYS)
 # define xfs_rtbuf_get(m,t,b,i,p)                       (ENOSYS)
+# define xfs_verify_rtbno(m, r)			(false)
 static inline int		/* error */
 xfs_rtmount_init(
 	xfs_mount_t	*mp)	/* file system mount structure */

fs/xfs/xfs_trace.h

···
 		   __entry->bt_before)
 );
 
-TRACE_EVENT(xfs_iext_insert,
-	TP_PROTO(struct xfs_inode *ip, xfs_extnum_t idx,
-		 struct xfs_bmbt_irec *r, int state, unsigned long caller_ip),
-	TP_ARGS(ip, idx, r, state, caller_ip),
-	TP_STRUCT__entry(
-		__field(dev_t, dev)
-		__field(xfs_ino_t, ino)
-		__field(xfs_extnum_t, idx)
-		__field(xfs_fileoff_t, startoff)
-		__field(xfs_fsblock_t, startblock)
-		__field(xfs_filblks_t, blockcount)
-		__field(xfs_exntst_t, state)
-		__field(int, bmap_state)
-		__field(unsigned long, caller_ip)
-	),
-	TP_fast_assign(
-		__entry->dev = VFS_I(ip)->i_sb->s_dev;
-		__entry->ino = ip->i_ino;
-		__entry->idx = idx;
-		__entry->startoff = r->br_startoff;
-		__entry->startblock = r->br_startblock;
-		__entry->blockcount = r->br_blockcount;
-		__entry->state = r->br_state;
-		__entry->bmap_state = state;
-		__entry->caller_ip = caller_ip;
-	),
-	TP_printk("dev %d:%d ino 0x%llx state %s idx %ld "
-		  "offset %lld block %lld count %lld flag %d caller %ps",
-		  MAJOR(__entry->dev), MINOR(__entry->dev),
-		  __entry->ino,
-		  __print_flags(__entry->bmap_state, "|", XFS_BMAP_EXT_FLAGS),
-		  (long)__entry->idx,
-		  __entry->startoff,
-		  (int64_t)__entry->startblock,
-		  __entry->blockcount,
-		  __entry->state,
-		  (char *)__entry->caller_ip)
-);
-
 DECLARE_EVENT_CLASS(xfs_bmap_class,
-	TP_PROTO(struct xfs_inode *ip, xfs_extnum_t idx, int state,
+	TP_PROTO(struct xfs_inode *ip, struct xfs_iext_cursor *cur, int state,
 		 unsigned long caller_ip),
-	TP_ARGS(ip, idx, state, caller_ip),
+	TP_ARGS(ip, cur, state, caller_ip),
 	TP_STRUCT__entry(
 		__field(dev_t, dev)
 		__field(xfs_ino_t, ino)
-		__field(xfs_extnum_t, idx)
+		__field(void *, leaf);
+		__field(int, pos);
 		__field(xfs_fileoff_t, startoff)
 		__field(xfs_fsblock_t, startblock)
 		__field(xfs_filblks_t, blockcount)
···
 		struct xfs_bmbt_irec	r;
 
 		ifp = xfs_iext_state_to_fork(ip, state);
-		xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &r);
+		xfs_iext_get_extent(ifp, cur, &r);
 		__entry->dev = VFS_I(ip)->i_sb->s_dev;
 		__entry->ino = ip->i_ino;
-		__entry->idx = idx;
+		__entry->leaf = cur->leaf;
+		__entry->pos = cur->pos;
 		__entry->startoff = r.br_startoff;
 		__entry->startblock = r.br_startblock;
 		__entry->blockcount = r.br_blockcount;
···
 		__entry->bmap_state = state;
 		__entry->caller_ip = caller_ip;
 	),
-	TP_printk("dev %d:%d ino 0x%llx state %s idx %ld "
+	TP_printk("dev %d:%d ino 0x%llx state %s cur 0x%p/%d "
 		  "offset %lld block %lld count %lld flag %d caller %ps",
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->ino,
 		  __print_flags(__entry->bmap_state, "|", XFS_BMAP_EXT_FLAGS),
-		  (long)__entry->idx,
+		  __entry->leaf,
+		  __entry->pos,
 		  __entry->startoff,
 		  (int64_t)__entry->startblock,
 		  __entry->blockcount,
···
 
 #define DEFINE_BMAP_EVENT(name) \
 DEFINE_EVENT(xfs_bmap_class, name, \
-	TP_PROTO(struct xfs_inode *ip, xfs_extnum_t idx, int state, \
+	TP_PROTO(struct xfs_inode *ip, struct xfs_iext_cursor *cur, int state, \
 		 unsigned long caller_ip), \
-	TP_ARGS(ip, idx, state, caller_ip))
+	TP_ARGS(ip, cur, state, caller_ip))
+DEFINE_BMAP_EVENT(xfs_iext_insert);
 DEFINE_BMAP_EVENT(xfs_iext_remove);
 DEFINE_BMAP_EVENT(xfs_bmap_pre_update);
 DEFINE_BMAP_EVENT(xfs_bmap_post_update);
-DEFINE_BMAP_EVENT(xfs_extlist);
+DEFINE_BMAP_EVENT(xfs_read_extent);
+DEFINE_BMAP_EVENT(xfs_write_extent);
 
 DECLARE_EVENT_CLASS(xfs_buf_class,
 	TP_PROTO(struct xfs_buf *bp, unsigned long caller_ip),

fs/xfs/xfs_trans_ail.c

···
 #include "xfs_trans.h"
 #include "xfs_trans_priv.h"
 #include "xfs_trace.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_log.h"
 
···
 	current->flags |= PF_MEMALLOC;
 	set_freezable();
 
-	while (!kthread_should_stop()) {
+	while (1) {
 		if (tout && tout <= 20)
-			__set_current_state(TASK_KILLABLE);
+			set_current_state(TASK_KILLABLE);
 		else
-			__set_current_state(TASK_INTERRUPTIBLE);
+			set_current_state(TASK_INTERRUPTIBLE);
+
+		/*
+		 * Check kthread_should_stop() after we set the task state
+		 * to guarantee that we either see the stop bit and exit or
+		 * the task state is reset to runnable such that it's not
+		 * scheduled out indefinitely and detects the stop bit at
+		 * next iteration.
+		 *
+		 * A memory barrier is included in above task state set to
+		 * serialize again kthread_stop().
+		 */
+		if (kthread_should_stop()) {
+			__set_current_state(TASK_RUNNING);
+			break;
+		}
 
 		spin_lock(&ailp->xa_lock);