Merge branch 'xfs-sb-logging-rework' into for-next

Conflicts:
fs/xfs/xfs_mount.c

fs/xfs/libxfs/xfs_attr_leaf.c

···
 		if (!xfs_sb_version_hasattr2(&mp->m_sb)) {
 			xfs_sb_version_addattr2(&mp->m_sb);
 			spin_unlock(&mp->m_sb_lock);
-			xfs_mod_sb(tp, XFS_SB_VERSIONNUM | XFS_SB_FEATURES2);
+			xfs_log_sb(tp);
 		} else
 			spin_unlock(&mp->m_sb_lock);
 	}

fs/xfs/libxfs/xfs_bmap.c

···
 		goto bmap_cancel;
 	if (!xfs_sb_version_hasattr(&mp->m_sb) ||
 	   (!xfs_sb_version_hasattr2(&mp->m_sb) && version == 2)) {
-		__int64_t sbfields = 0;
+		bool log_sb = false;
 
 		spin_lock(&mp->m_sb_lock);
 		if (!xfs_sb_version_hasattr(&mp->m_sb)) {
 			xfs_sb_version_addattr(&mp->m_sb);
-			sbfields |= XFS_SB_VERSIONNUM;
+			log_sb = true;
 		}
 		if (!xfs_sb_version_hasattr2(&mp->m_sb) && version == 2) {
 			xfs_sb_version_addattr2(&mp->m_sb);
-			sbfields |= (XFS_SB_VERSIONNUM | XFS_SB_FEATURES2);
+			log_sb = true;
 		}
-		if (sbfields) {
-			spin_unlock(&mp->m_sb_lock);
-			xfs_mod_sb(tp, sbfields);
-		} else
-			spin_unlock(&mp->m_sb_lock);
+		spin_unlock(&mp->m_sb_lock);
+		if (log_sb)
+			xfs_log_sb(tp);
 	}
 
 	error = xfs_bmap_finish(&tp, &flist, &committed);

fs/xfs/libxfs/xfs_format.h

···
 	__uint32_t	sb_features2;	/* additional feature bits */
 
 	/*
-	 * bad features2 field as a result of failing to pad the sb
-	 * structure to 64 bits. Some machines will be using this field
-	 * for features2 bits. Easiest just to mark it bad and not use
-	 * it for anything else.
+	 * bad features2 field as a result of failing to pad the sb structure to
+	 * 64 bits. Some machines will be using this field for features2 bits.
+	 * Easiest just to mark it bad and not use it for anything else.
+	 *
+	 * This is not kept up to date in memory; it is always overwritten by
+	 * the value in sb_features2 when formatting the incore superblock to
+	 * the disk buffer.
 	 */
 	__uint32_t	sb_bad_features2;
 
···
 {
 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
 	sbp->sb_features2 |= XFS_SB_VERSION2_ATTR2BIT;
-	sbp->sb_bad_features2 |= XFS_SB_VERSION2_ATTR2BIT;
 }
 
 static inline void xfs_sb_version_removeattr2(struct xfs_sb *sbp)
 {
 	sbp->sb_features2 &= ~XFS_SB_VERSION2_ATTR2BIT;
-	sbp->sb_bad_features2 &= ~XFS_SB_VERSION2_ATTR2BIT;
 	if (!sbp->sb_features2)
 		sbp->sb_versionnum &= ~XFS_SB_VERSION_MOREBITSBIT;
 }
···
 {
 	sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
 	sbp->sb_features2 |= XFS_SB_VERSION2_PROJID32BIT;
-	sbp->sb_bad_features2 |= XFS_SB_VERSION2_PROJID32BIT;
 }
 
 /*

fs/xfs/libxfs/xfs_sb.c

···
  * Physical superblock buffer manipulations. Shared with libxfs in userspace.
  */
 
-static const struct {
-	short offset;
-	short type;	/* 0 = integer
-			 * 1 = binary / string (no translation)
-			 */
-} xfs_sb_info[] = {
-	{ offsetof(xfs_sb_t, sb_magicnum),	0 },
-	{ offsetof(xfs_sb_t, sb_blocksize),	0 },
-	{ offsetof(xfs_sb_t, sb_dblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_rblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_rextents),	0 },
-	{ offsetof(xfs_sb_t, sb_uuid),		1 },
-	{ offsetof(xfs_sb_t, sb_logstart),	0 },
-	{ offsetof(xfs_sb_t, sb_rootino),	0 },
-	{ offsetof(xfs_sb_t, sb_rbmino),	0 },
-	{ offsetof(xfs_sb_t, sb_rsumino),	0 },
-	{ offsetof(xfs_sb_t, sb_rextsize),	0 },
-	{ offsetof(xfs_sb_t, sb_agblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_agcount),	0 },
-	{ offsetof(xfs_sb_t, sb_rbmblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_logblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_versionnum),	0 },
-	{ offsetof(xfs_sb_t, sb_sectsize),	0 },
-	{ offsetof(xfs_sb_t, sb_inodesize),	0 },
-	{ offsetof(xfs_sb_t, sb_inopblock),	0 },
-	{ offsetof(xfs_sb_t, sb_fname[0]),	1 },
-	{ offsetof(xfs_sb_t, sb_blocklog),	0 },
-	{ offsetof(xfs_sb_t, sb_sectlog),	0 },
-	{ offsetof(xfs_sb_t, sb_inodelog),	0 },
-	{ offsetof(xfs_sb_t, sb_inopblog),	0 },
-	{ offsetof(xfs_sb_t, sb_agblklog),	0 },
-	{ offsetof(xfs_sb_t, sb_rextslog),	0 },
-	{ offsetof(xfs_sb_t, sb_inprogress),	0 },
-	{ offsetof(xfs_sb_t, sb_imax_pct),	0 },
-	{ offsetof(xfs_sb_t, sb_icount),	0 },
-	{ offsetof(xfs_sb_t, sb_ifree),		0 },
-	{ offsetof(xfs_sb_t, sb_fdblocks),	0 },
-	{ offsetof(xfs_sb_t, sb_frextents),	0 },
-	{ offsetof(xfs_sb_t, sb_uquotino),	0 },
-	{ offsetof(xfs_sb_t, sb_gquotino),	0 },
-	{ offsetof(xfs_sb_t, sb_qflags),	0 },
-	{ offsetof(xfs_sb_t, sb_flags),		0 },
-	{ offsetof(xfs_sb_t, sb_shared_vn),	0 },
-	{ offsetof(xfs_sb_t, sb_inoalignmt),	0 },
-	{ offsetof(xfs_sb_t, sb_unit),		0 },
-	{ offsetof(xfs_sb_t, sb_width),		0 },
-	{ offsetof(xfs_sb_t, sb_dirblklog),	0 },
-	{ offsetof(xfs_sb_t, sb_logsectlog),	0 },
-	{ offsetof(xfs_sb_t, sb_logsectsize),	0 },
-	{ offsetof(xfs_sb_t, sb_logsunit),	0 },
-	{ offsetof(xfs_sb_t, sb_features2),	0 },
-	{ offsetof(xfs_sb_t, sb_bad_features2),	0 },
-	{ offsetof(xfs_sb_t, sb_features_compat),	0 },
-	{ offsetof(xfs_sb_t, sb_features_ro_compat),	0 },
-	{ offsetof(xfs_sb_t, sb_features_incompat),	0 },
-	{ offsetof(xfs_sb_t, sb_features_log_incompat),	0 },
-	{ offsetof(xfs_sb_t, sb_crc),		0 },
-	{ offsetof(xfs_sb_t, sb_pad),		0 },
-	{ offsetof(xfs_sb_t, sb_pquotino),	0 },
-	{ offsetof(xfs_sb_t, sb_lsn),		0 },
-	{ sizeof(xfs_sb_t),			0 }
-};
-
 /*
  * Reference counting access wrappers to the perag structures.
  * Because we never free per-ag structures, the only thing we
···
 	__xfs_sb_from_disk(to, from, true);
 }
 
-static inline void
+static void
 xfs_sb_quota_to_disk(
-	xfs_dsb_t	*to,
-	xfs_sb_t	*from,
-	__int64_t	*fields)
+	struct xfs_dsb	*to,
+	struct xfs_sb	*from)
 {
 	__uint16_t	qflags = from->sb_qflags;
 
-	/*
-	 * We need to do these manipilations only if we are working
-	 * with an older version of on-disk superblock.
-	 */
-	if (xfs_sb_version_has_pquotino(from))
+	to->sb_uquotino = cpu_to_be64(from->sb_uquotino);
+	if (xfs_sb_version_has_pquotino(from)) {
+		to->sb_qflags = cpu_to_be16(from->sb_qflags);
+		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
+		to->sb_pquotino = cpu_to_be64(from->sb_pquotino);
 		return;
-
-	if (*fields & XFS_SB_QFLAGS) {
-		/*
-		 * The in-core version of sb_qflags do not have
-		 * XFS_OQUOTA_* flags, whereas the on-disk version
-		 * does.  So, convert incore XFS_{PG}QUOTA_* flags
-		 * to on-disk XFS_OQUOTA_* flags.
-		 */
-		qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
-				XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
-
-		if (from->sb_qflags &
-				(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
-			qflags |= XFS_OQUOTA_ENFD;
-		if (from->sb_qflags &
-				(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
-			qflags |= XFS_OQUOTA_CHKD;
-		to->sb_qflags = cpu_to_be16(qflags);
-		*fields &= ~XFS_SB_QFLAGS;
 	}
 
 	/*
-	 * GQUOTINO and PQUOTINO cannot be used together in versions of
-	 * superblock that do not have pquotino. from->sb_flags tells us which
-	 * quota is active and should be copied to disk. If neither are active,
-	 * make sure we write NULLFSINO to the sb_gquotino field as a quota
-	 * inode value of "0" is invalid when the XFS_SB_VERSION_QUOTA feature
-	 * bit is set.
-	 *
-	 * Note that we don't need to handle the sb_uquotino or sb_pquotino here
-	 * as they do not require any translation. Hence the main sb field loop
-	 * will write them appropriately from the in-core superblock.
+	 * The in-core version of sb_qflags do not have XFS_OQUOTA_*
+	 * flags, whereas the on-disk version does.  So, convert incore
+	 * XFS_{PG}QUOTA_* flags to on-disk XFS_OQUOTA_* flags.
 	 */
-	if ((*fields & XFS_SB_GQUOTINO) &&
-				(from->sb_qflags & XFS_GQUOTA_ACCT))
+	qflags &= ~(XFS_PQUOTA_ENFD | XFS_PQUOTA_CHKD |
+			XFS_GQUOTA_ENFD | XFS_GQUOTA_CHKD);
+
+	if (from->sb_qflags &
+			(XFS_PQUOTA_ENFD | XFS_GQUOTA_ENFD))
+		qflags |= XFS_OQUOTA_ENFD;
+	if (from->sb_qflags &
+			(XFS_PQUOTA_CHKD | XFS_GQUOTA_CHKD))
+		qflags |= XFS_OQUOTA_CHKD;
+	to->sb_qflags = cpu_to_be16(qflags);
+
+	/*
+	 * GQUOTINO and PQUOTINO cannot be used together in versions
+	 * of superblock that do not have pquotino. from->sb_flags
+	 * tells us which quota is active and should be copied to
+	 * disk. If neither are active, we should NULL the inode.
+	 *
+	 * In all cases, the separate pquotino must remain 0 because it
+	 * it beyond the "end" of the valid non-pquotino superblock.
+	 */
+	if (from->sb_qflags & XFS_GQUOTA_ACCT)
 		to->sb_gquotino = cpu_to_be64(from->sb_gquotino);
-	else if ((*fields & XFS_SB_PQUOTINO) &&
-				(from->sb_qflags & XFS_PQUOTA_ACCT))
+	else if (from->sb_qflags & XFS_PQUOTA_ACCT)
 		to->sb_gquotino = cpu_to_be64(from->sb_pquotino);
 	else {
 		/*
···
 			to->sb_gquotino = cpu_to_be64(NULLFSINO);
 	}
 
-	*fields &= ~(XFS_SB_PQUOTINO | XFS_SB_GQUOTINO);
+	to->sb_pquotino = 0;
 }
 
-/*
- * Copy in core superblock to ondisk one.
- *
- * The fields argument is mask of superblock fields to copy.
- */
 void
 xfs_sb_to_disk(
-	xfs_dsb_t	*to,
-	xfs_sb_t	*from,
-	__int64_t	fields)
+	struct xfs_dsb	*to,
+	struct xfs_sb	*from)
 {
-	xfs_caddr_t	to_ptr = (xfs_caddr_t)to;
-	xfs_caddr_t	from_ptr = (xfs_caddr_t)from;
-	xfs_sb_field_t	f;
-	int		first;
-	int		size;
+	xfs_sb_quota_to_disk(to, from);
 
-	ASSERT(fields);
-	if (!fields)
-		return;
+	to->sb_magicnum = cpu_to_be32(from->sb_magicnum);
+	to->sb_blocksize = cpu_to_be32(from->sb_blocksize);
+	to->sb_dblocks = cpu_to_be64(from->sb_dblocks);
+	to->sb_rblocks = cpu_to_be64(from->sb_rblocks);
+	to->sb_rextents = cpu_to_be64(from->sb_rextents);
+	memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
+	to->sb_logstart = cpu_to_be64(from->sb_logstart);
+	to->sb_rootino = cpu_to_be64(from->sb_rootino);
+	to->sb_rbmino = cpu_to_be64(from->sb_rbmino);
+	to->sb_rsumino = cpu_to_be64(from->sb_rsumino);
+	to->sb_rextsize = cpu_to_be32(from->sb_rextsize);
+	to->sb_agblocks = cpu_to_be32(from->sb_agblocks);
+	to->sb_agcount = cpu_to_be32(from->sb_agcount);
+	to->sb_rbmblocks = cpu_to_be32(from->sb_rbmblocks);
+	to->sb_logblocks = cpu_to_be32(from->sb_logblocks);
+	to->sb_versionnum = cpu_to_be16(from->sb_versionnum);
+	to->sb_sectsize = cpu_to_be16(from->sb_sectsize);
+	to->sb_inodesize = cpu_to_be16(from->sb_inodesize);
+	to->sb_inopblock = cpu_to_be16(from->sb_inopblock);
+	memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
+	to->sb_blocklog = from->sb_blocklog;
+	to->sb_sectlog = from->sb_sectlog;
+	to->sb_inodelog = from->sb_inodelog;
+	to->sb_inopblog = from->sb_inopblog;
+	to->sb_agblklog = from->sb_agblklog;
+	to->sb_rextslog = from->sb_rextslog;
+	to->sb_inprogress = from->sb_inprogress;
+	to->sb_imax_pct = from->sb_imax_pct;
+	to->sb_icount = cpu_to_be64(from->sb_icount);
+	to->sb_ifree = cpu_to_be64(from->sb_ifree);
+	to->sb_fdblocks = cpu_to_be64(from->sb_fdblocks);
+	to->sb_frextents = cpu_to_be64(from->sb_frextents);
 
-	/* We should never write the crc here, it's updated in the IO path */
-	fields &= ~XFS_SB_CRC;
+	to->sb_flags = from->sb_flags;
+	to->sb_shared_vn = from->sb_shared_vn;
+	to->sb_inoalignmt = cpu_to_be32(from->sb_inoalignmt);
+	to->sb_unit = cpu_to_be32(from->sb_unit);
+	to->sb_width = cpu_to_be32(from->sb_width);
+	to->sb_dirblklog = from->sb_dirblklog;
+	to->sb_logsectlog = from->sb_logsectlog;
+	to->sb_logsectsize = cpu_to_be16(from->sb_logsectsize);
+	to->sb_logsunit = cpu_to_be32(from->sb_logsunit);
 
-	xfs_sb_quota_to_disk(to, from, &fields);
-	while (fields) {
-		f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
-		first = xfs_sb_info[f].offset;
-		size = xfs_sb_info[f + 1].offset - first;
+	/*
+	 * We need to ensure that bad_features2 always matches features2.
+	 * Hence we enforce that here rather than having to remember to do it
+	 * everywhere else that updates features2.
+	 */
+	from->sb_bad_features2 = from->sb_features2;
+	to->sb_features2 = cpu_to_be32(from->sb_features2);
+	to->sb_bad_features2 = cpu_to_be32(from->sb_bad_features2);
 
-		ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
-
-		if (size == 1 || xfs_sb_info[f].type == 1) {
-			memcpy(to_ptr + first, from_ptr + first, size);
-		} else {
-			switch (size) {
-			case 2:
-				*(__be16 *)(to_ptr + first) =
-				      cpu_to_be16(*(__u16 *)(from_ptr + first));
-				break;
-			case 4:
-				*(__be32 *)(to_ptr + first) =
-				      cpu_to_be32(*(__u32 *)(from_ptr + first));
-				break;
-			case 8:
-				*(__be64 *)(to_ptr + first) =
-				      cpu_to_be64(*(__u64 *)(from_ptr + first));
-				break;
-			default:
-				ASSERT(0);
-			}
-		}
-
-		fields &= ~(1LL << f);
+	if (xfs_sb_version_hascrc(from)) {
+		to->sb_features_compat = cpu_to_be32(from->sb_features_compat);
+		to->sb_features_ro_compat =
+				cpu_to_be32(from->sb_features_ro_compat);
+		to->sb_features_incompat =
+				cpu_to_be32(from->sb_features_incompat);
+		to->sb_features_log_incompat =
+				cpu_to_be32(from->sb_features_log_incompat);
+		to->sb_pad = 0;
+		to->sb_lsn = cpu_to_be64(from->sb_lsn);
 	}
 }
 
···
 }
 
 /*
- * xfs_mod_sb() can be used to copy arbitrary changes to the
- * in-core superblock into the superblock buffer to be logged.
- * It does not provide the higher level of locking that is
- * needed to protect the in-core superblock from concurrent
- * access.
+ * xfs_log_sb() can be used to copy arbitrary changes to the in-core superblock
+ * into the superblock buffer to be logged.  It does not provide the higher
+ * level of locking that is needed to protect the in-core superblock from
+ * concurrent access.
  */
 void
-xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
+xfs_log_sb(
+	struct xfs_trans	*tp)
 {
-	xfs_buf_t	*bp;
-	int		first;
-	int		last;
-	xfs_mount_t	*mp;
-	xfs_sb_field_t	f;
+	struct xfs_mount	*mp = tp->t_mountp;
+	struct xfs_buf		*bp = xfs_trans_getsb(tp, mp, 0);
 
-	ASSERT(fields);
-	if (!fields)
-		return;
-	mp = tp->t_mountp;
-	bp = xfs_trans_getsb(tp, mp, 0);
-	first = sizeof(xfs_sb_t);
-	last = 0;
-
-	/* translate/copy */
-
-	xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
-
-	/* find modified range */
-	f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
-	ASSERT((1LL << f) & XFS_SB_MOD_BITS);
-	last = xfs_sb_info[f + 1].offset - 1;
-
-	f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
-	ASSERT((1LL << f) & XFS_SB_MOD_BITS);
-	first = xfs_sb_info[f].offset;
-
+	xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
 	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
-	xfs_trans_log_buf(tp, bp, first, last);
+	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsb));
+}
+
+/*
+ * xfs_sync_sb
+ *
+ * Sync the superblock to disk.
+ *
+ * Note that the caller is responsible for checking the frozen state of the
+ * filesystem. This procedure uses the non-blocking transaction allocator and
+ * thus will allow modifications to a frozen fs. This is required because this
+ * code can be called during the process of freezing where use of the high-level
+ * allocator would deadlock.
+ */
+int
+xfs_sync_sb(
+	struct xfs_mount	*mp,
+	bool			wait)
+{
+	struct xfs_trans	*tp;
+	int			error;
+
+	tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_CHANGE, KM_SLEEP);
+	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
+	if (error) {
+		xfs_trans_cancel(tp, 0);
+		return error;
+	}
+
+	xfs_log_sb(tp);
+	if (wait)
+		xfs_trans_set_sync(tp);
+	return xfs_trans_commit(tp, 0);
 }

fs/xfs/libxfs/xfs_sb.h

···
 extern void	xfs_perag_put(struct xfs_perag *pag);
 extern int	xfs_initialize_perag_data(struct xfs_mount *, xfs_agnumber_t);
 
-extern void	xfs_sb_calc_crc(struct xfs_buf	*);
-extern void	xfs_mod_sb(struct xfs_trans *, __int64_t);
-extern void	xfs_sb_mount_common(struct xfs_mount *, struct xfs_sb *);
-extern void	xfs_sb_from_disk(struct xfs_sb *, struct xfs_dsb *);
-extern void	xfs_sb_to_disk(struct xfs_dsb *, struct xfs_sb *, __int64_t);
+extern void	xfs_sb_calc_crc(struct xfs_buf *bp);
+extern void	xfs_log_sb(struct xfs_trans *tp);
+extern int	xfs_sync_sb(struct xfs_mount *mp, bool wait);
+extern void	xfs_sb_mount_common(struct xfs_mount *mp, struct xfs_sb *sbp);
+extern void	xfs_sb_from_disk(struct xfs_sb *to, struct xfs_dsb *from);
+extern void	xfs_sb_to_disk(struct xfs_dsb *to, struct xfs_sb *from);
 extern void	xfs_sb_quota_from_disk(struct xfs_sb *sbp);
 
 #endif	/* __XFS_SB_H__ */

fs/xfs/libxfs/xfs_shared.h

···
 #define	XFS_TRANS_ATTR_RM		23
 #define	XFS_TRANS_ATTR_FLAG		24
 #define	XFS_TRANS_CLEAR_AGI_BUCKET	25
-#define XFS_TRANS_QM_SBCHANGE		26
+#define XFS_TRANS_SB_CHANGE		26
 /*
  * Dummy entries since we use the transaction type to index into the
  * trans_type[] in xlog_recover_print_trans_head()
···
 #define XFS_TRANS_QM_DQCLUSTER		32
 #define XFS_TRANS_QM_QINOCREATE		33
 #define XFS_TRANS_QM_QUOTAOFF_END	34
-#define XFS_TRANS_SB_UNIT		35
-#define XFS_TRANS_FSYNC_TS		36
-#define	XFS_TRANS_GROWFSRT_ALLOC	37
-#define	XFS_TRANS_GROWFSRT_ZERO		38
-#define	XFS_TRANS_GROWFSRT_FREE		39
-#define	XFS_TRANS_SWAPEXT		40
-#define	XFS_TRANS_SB_COUNT		41
-#define	XFS_TRANS_CHECKPOINT		42
-#define	XFS_TRANS_ICREATE		43
-#define	XFS_TRANS_CREATE_TMPFILE	44
-#define	XFS_TRANS_TYPE_MAX		44
+#define XFS_TRANS_FSYNC_TS		35
+#define	XFS_TRANS_GROWFSRT_ALLOC	36
+#define	XFS_TRANS_GROWFSRT_ZERO		37
+#define	XFS_TRANS_GROWFSRT_FREE		38
+#define	XFS_TRANS_SWAPEXT		39
+#define	XFS_TRANS_CHECKPOINT		40
+#define	XFS_TRANS_ICREATE		41
+#define	XFS_TRANS_CREATE_TMPFILE	42
+#define	XFS_TRANS_TYPE_MAX		43
 /* new transaction types need to be reflected in xfs_logprint(8) */
 
 #define XFS_TRANS_TYPES \
···
 	{ XFS_TRANS_SETATTR_SIZE,	"SETATTR_SIZE" }, \
 	{ XFS_TRANS_INACTIVE,		"INACTIVE" }, \
 	{ XFS_TRANS_CREATE,		"CREATE" }, \
-	{ XFS_TRANS_CREATE_TMPFILE,	"CREATE_TMPFILE" }, \
 	{ XFS_TRANS_CREATE_TRUNC,	"CREATE_TRUNC" }, \
 	{ XFS_TRANS_TRUNCATE_FILE,	"TRUNCATE_FILE" }, \
 	{ XFS_TRANS_REMOVE,		"REMOVE" }, \
···
 	{ XFS_TRANS_ATTR_RM,		"ATTR_RM" }, \
 	{ XFS_TRANS_ATTR_FLAG,		"ATTR_FLAG" }, \
 	{ XFS_TRANS_CLEAR_AGI_BUCKET,	"CLEAR_AGI_BUCKET" }, \
-	{ XFS_TRANS_QM_SBCHANGE,	"QM_SBCHANGE" }, \
+	{ XFS_TRANS_SB_CHANGE,		"SBCHANGE" }, \
+	{ XFS_TRANS_DUMMY1,		"DUMMY1" }, \
+	{ XFS_TRANS_DUMMY2,		"DUMMY2" }, \
 	{ XFS_TRANS_QM_QUOTAOFF,	"QM_QUOTAOFF" }, \
 	{ XFS_TRANS_QM_DQALLOC,		"QM_DQALLOC" }, \
 	{ XFS_TRANS_QM_SETQLIM,		"QM_SETQLIM" }, \
 	{ XFS_TRANS_QM_DQCLUSTER,	"QM_DQCLUSTER" }, \
 	{ XFS_TRANS_QM_QINOCREATE,	"QM_QINOCREATE" }, \
 	{ XFS_TRANS_QM_QUOTAOFF_END,	"QM_QOFF_END" }, \
-	{ XFS_TRANS_SB_UNIT,		"SB_UNIT" }, \
 	{ XFS_TRANS_FSYNC_TS,		"FSYNC_TS" }, \
 	{ XFS_TRANS_GROWFSRT_ALLOC,	"GROWFSRT_ALLOC" }, \
 	{ XFS_TRANS_GROWFSRT_ZERO,	"GROWFSRT_ZERO" }, \
 	{ XFS_TRANS_GROWFSRT_FREE,	"GROWFSRT_FREE" }, \
 	{ XFS_TRANS_SWAPEXT,		"SWAPEXT" }, \
-	{ XFS_TRANS_SB_COUNT,		"SB_COUNT" }, \
 	{ XFS_TRANS_CHECKPOINT,		"CHECKPOINT" }, \
-	{ XFS_TRANS_DUMMY1,		"DUMMY1" }, \
-	{ XFS_TRANS_DUMMY2,		"DUMMY2" }, \
+	{ XFS_TRANS_ICREATE,		"ICREATE" }, \
+	{ XFS_TRANS_CREATE_TMPFILE,	"CREATE_TMPFILE" }, \
 	{ XLOG_UNMOUNT_REC_TYPE,	"UNMOUNT" }
 
 /*

fs/xfs/libxfs/xfs_trans_resv.c

···
 }
 
 /*
- * Clearing the quotaflags in the superblock.
- *	the super block for changing quota flags: sector size
- */
-STATIC uint
-xfs_calc_qm_sbchange_reservation(
-	struct xfs_mount	*mp)
-{
-	return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize);
-}
-
-/*
  * Adjusting quota limits.
  *    the xfs_disk_dquot_t: sizeof(struct xfs_disk_dquot)
  */
···
 	 * The following transactions are logged in logical format with
 	 * a default log count.
 	 */
-	resp->tr_qm_sbchange.tr_logres = xfs_calc_qm_sbchange_reservation(mp);
-	resp->tr_qm_sbchange.tr_logcount = XFS_DEFAULT_LOG_COUNT;
-
 	resp->tr_qm_setqlim.tr_logres = xfs_calc_qm_setqlim_reservation(mp);
 	resp->tr_qm_setqlim.tr_logcount = XFS_DEFAULT_LOG_COUNT;
 

fs/xfs/libxfs/xfs_trans_resv.h

···
 	struct xfs_trans_res	tr_growrtalloc;	/* grow realtime allocations */
 	struct xfs_trans_res	tr_growrtzero;	/* grow realtime zeroing */
 	struct xfs_trans_res	tr_growrtfree;	/* grow realtime freeing */
-	struct xfs_trans_res	tr_qm_sbchange;	/* change quota flags */
 	struct xfs_trans_res	tr_qm_setqlim;	/* adjust quota limits */
 	struct xfs_trans_res	tr_qm_dqalloc;	/* allocate quota on disk */
 	struct xfs_trans_res	tr_qm_quotaoff;	/* turn quota off */

fs/xfs/xfs_fsops.c

···
 			saved_error = error;
 			continue;
 		}
-		xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, XFS_SB_ALL_BITS);
+		xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
 
 		error = xfs_bwrite(bp);
 		xfs_buf_relse(bp);
···
 			goto retry;
 	}
 	return 0;
-}
-
-/*
- * Dump a transaction into the log that contains no real change. This is needed
- * to be able to make the log dirty or stamp the current tail LSN into the log
- * during the covering operation.
- *
- * We cannot use an inode here for this - that will push dirty state back up
- * into the VFS and then periodic inode flushing will prevent log covering from
- * making progress. Hence we log a field in the superblock instead and use a
- * synchronous transaction to ensure the superblock is immediately unpinned
- * and can be written back.
- */
-int
-xfs_fs_log_dummy(
-	xfs_mount_t	*mp)
-{
-	xfs_trans_t	*tp;
-	int		error;
-
-	tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1, KM_SLEEP);
-	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
-	if (error) {
-		xfs_trans_cancel(tp, 0);
-		return error;
-	}
-
-	/* log the UUID because it is an unchanging field */
-	xfs_mod_sb(tp, XFS_SB_UUID);
-	xfs_trans_set_sync(tp);
-	return xfs_trans_commit(tp, 0);
 }
 
 int

fs/xfs/xfs_log.c

···
 #include "xfs_fsops.h"
 #include "xfs_cksum.h"
 #include "xfs_sysfs.h"
+#include "xfs_sb.h"
 
 kmem_zone_t	*xfs_log_ticket_zone;
 
···
 	struct xfs_mount	*mp = log->l_mp;
 
 	/* dgc: errors ignored - not fatal and nowhere to report them */
-	if (xfs_log_need_covered(mp))
-		xfs_fs_log_dummy(mp);
-	else
+	if (xfs_log_need_covered(mp)) {
+		/*
+		 * Dump a transaction into the log that contains no real change.
+		 * This is needed to stamp the current tail LSN into the log
+		 * during the covering operation.
+		 *
+		 * We cannot use an inode here for this - that will push dirty
+		 * state back up into the VFS and then periodic inode flushing
+		 * will prevent log covering from making progress. Hence we
+		 * synchronously log the superblock instead to ensure the
+		 * superblock is immediately unpinned and can be written back.
+		 */
+		xfs_sync_sb(mp, true);
+	} else
 		xfs_log_force(mp, 0);
 
 	/* start pushing all the metadata that is currently dirty */

fs/xfs/xfs_mount.c

···
 		if (xfs_sb_version_hasdalign(sbp)) {
 			if (sbp->sb_unit != mp->m_dalign) {
 				sbp->sb_unit = mp->m_dalign;
-				mp->m_update_flags |= XFS_SB_UNIT;
+				mp->m_update_sb = true;
 			}
 			if (sbp->sb_width != mp->m_swidth) {
 				sbp->sb_width = mp->m_swidth;
-				mp->m_update_flags |= XFS_SB_WIDTH;
+				mp->m_update_sb = true;
 			}
 		} else {
 			xfs_warn(mp,
···
 xfs_mount_reset_sbqflags(
 	struct xfs_mount	*mp)
 {
-	int			error;
-	struct xfs_trans	*tp;
-
 	mp->m_qflags = 0;
 
-	/*
-	 * It is OK to look at sb_qflags here in mount path,
-	 * without m_sb_lock.
-	 */
+	/* It is OK to look at sb_qflags in the mount path without m_sb_lock. */
 	if (mp->m_sb.sb_qflags == 0)
 		return 0;
 	spin_lock(&mp->m_sb_lock);
 	mp->m_sb.sb_qflags = 0;
 	spin_unlock(&mp->m_sb_lock);
 
-	/*
-	 * If the fs is readonly, let the incore superblock run
-	 * with quotas off but don't flush the update out to disk
-	 */
-	if (mp->m_flags & XFS_MOUNT_RDONLY)
+	if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
 		return 0;
 
-	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
-	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_sbchange, 0, 0);
-	if (error) {
-		xfs_trans_cancel(tp, 0);
-		xfs_alert(mp, "%s: Superblock update failed!", __func__);
-		return error;
-	}
-
-	xfs_mod_sb(tp, XFS_SB_QFLAGS);
-	return xfs_trans_commit(tp, 0);
+	return xfs_sync_sb(mp, false);
 }
 
 __uint64_t
···
 	xfs_sb_mount_common(mp, sbp);
 
 	/*
-	 * Check for a mismatched features2 values.  Older kernels
-	 * read & wrote into the wrong sb offset for sb_features2
-	 * on some platforms due to xfs_sb_t not being 64bit size aligned
-	 * when sb_features2 was added, which made older superblock
-	 * reading/writing routines swap it as a 64-bit value.
+	 * Check for a mismatched features2 values.  Older kernels read & wrote
+	 * into the wrong sb offset for sb_features2 on some platforms due to
+	 * xfs_sb_t not being 64bit size aligned when sb_features2 was added,
+	 * which made older superblock reading/writing routines swap it as a
+	 * 64-bit value.
 	 *
 	 * For backwards compatibility, we make both slots equal.
 	 *
-	 * If we detect a mismatched field, we OR the set bits into the
-	 * existing features2 field in case it has already been modified; we
-	 * don't want to lose any features.  We then update the bad location
-	 * with the ORed value so that older kernels will see any features2
-	 * flags, and mark the two fields as needing updates once the
-	 * transaction subsystem is online.
+	 * If we detect a mismatched field, we OR the set bits into the existing
+	 * features2 field in case it has already been modified; we don't want
+	 * to lose any features.  We then update the bad location with the ORed
+	 * value so that older kernels will see any features2 flags. The
+	 * superblock writeback code ensures the new sb_features2 is copied to
+	 * sb_bad_features2 before it is logged or written to disk.
 	 */
 	if (xfs_sb_has_mismatched_features2(sbp)) {
 		xfs_warn(mp, "correcting sb_features alignment problem");
 		sbp->sb_features2 |= sbp->sb_bad_features2;
-		sbp->sb_bad_features2 = sbp->sb_features2;
-		mp->m_update_flags |= XFS_SB_FEATURES2;
+		mp->m_update_sb = true;
 
 		/*
 		 * Re-check for ATTR2 in case it was found in bad_features2
···
 	if (xfs_sb_version_hasattr2(&mp->m_sb) &&
 	   (mp->m_flags & XFS_MOUNT_NOATTR2)) {
 		xfs_sb_version_removeattr2(&mp->m_sb);
-		mp->m_update_flags |= XFS_SB_FEATURES2;
+		mp->m_update_sb = true;
 
 		/* update sb_versionnum for the clearing of the morebits */
 		if (!sbp->sb_features2)
-			mp->m_update_flags |= XFS_SB_VERSIONNUM;
+			mp->m_update_sb = true;
 	}
 
 	/* always use v2 inodes by default now */
 	if (!(mp->m_sb.sb_versionnum & XFS_SB_VERSION_NLINKBIT)) {
 		mp->m_sb.sb_versionnum |= XFS_SB_VERSION_NLINKBIT;
-		mp->m_update_flags |= XFS_SB_VERSIONNUM;
+		mp->m_update_sb = true;
 	}
 
 	/*
···
 	 * the next remount into writeable mode.  Otherwise we would never
 	 * perform the update e.g. for the root filesystem.
 	 */
-	if (mp->m_update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
-		error = xfs_mount_log_sb(mp, mp->m_update_flags);
+	if (mp->m_update_sb && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
+		error = xfs_sync_sb(mp, false);
 		if (error) {
 			xfs_warn(mp, "failed to write sb changes");
 			goto out_rtunmount;
···
 int
 xfs_log_sbcount(xfs_mount_t *mp)
 {
-	xfs_trans_t	*tp;
-	int		error;
-
 	/* allow this to proceed during the freeze sequence... */
 	if (!xfs_fs_writable(mp, SB_FREEZE_COMPLETE))
 		return 0;
···
 	if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
 		return 0;
 
-	tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);
-	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
-	if (error) {
-		xfs_trans_cancel(tp, 0);
-		return error;
-	}
-
-	xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
-	xfs_trans_set_sync(tp);
-	error = xfs_trans_commit(tp, 0);
-	return error;
+	return xfs_sync_sb(mp, true);
 }
 
 /*
···
 	xfs_buf_lock(bp);
 	mp->m_sb_bp = NULL;
 	xfs_buf_relse(bp);
-}
-
-/*
- * Used to log changes to the superblock unit and width fields which could
- * be altered by the mount options, as well as any potential sb_features2
- * fixup. Only the first superblock is updated.
- */
-int
-xfs_mount_log_sb(
-	xfs_mount_t	*mp,
-	__int64_t	fields)
-{
-	xfs_trans_t	*tp;
-	int		error;
-
-	ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
-			 XFS_SB_FEATURES2 | XFS_SB_VERSIONNUM));
-
-	tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
-	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
-	if (error) {
-		xfs_trans_cancel(tp, 0);
-		return error;
-	}
-	xfs_mod_sb(tp, fields);
-	error = xfs_trans_commit(tp, 0);
-	return error;
 }
 
 /*

fs/xfs/xfs_mount.h

···
 	struct delayed_work	m_reclaim_work;	/* background inode reclaim */
 	struct delayed_work	m_eofblocks_work; /* background eof blocks
 						     trimming */
-	__int64_t		m_update_flags;	/* sb flags we need to update
-						   on the next remount,rw */
+	bool			m_update_sb;	/* sb needs update in mount */
 	int64_t			m_low_space[XFS_LOWSP_MAX];
 						/* low free space thresholds */
 	struct xfs_kobj		m_kobj;
···
 extern int	xfs_mod_incore_sb(xfs_mount_t *, xfs_sb_field_t, int64_t, int);
 extern int	xfs_mod_incore_sb_batch(xfs_mount_t *, xfs_mod_sb_t *,
 			uint, int);
-extern int	xfs_mount_log_sb(xfs_mount_t *, __int64_t);
+extern int	xfs_mount_log_sb(xfs_mount_t *);
 extern struct xfs_buf *xfs_getsb(xfs_mount_t *, int);
 extern int	xfs_readsb(xfs_mount_t *, int);
 extern void	xfs_freesb(xfs_mount_t *);

fs/xfs/xfs_qm.c

···
 xfs_qm_qino_alloc(
 	xfs_mount_t	*mp,
 	xfs_inode_t	**ip,
-	__int64_t	sbfields,
 	uint		flags)
 {
 	xfs_trans_t	*tp;
···
 	spin_lock(&mp->m_sb_lock);
 	if (flags & XFS_QMOPT_SBVERSION) {
 		ASSERT(!xfs_sb_version_hasquota(&mp->m_sb));
-		ASSERT((sbfields & (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
-			XFS_SB_GQUOTINO | XFS_SB_PQUOTINO | XFS_SB_QFLAGS)) ==
-				(XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
-				 XFS_SB_GQUOTINO | XFS_SB_PQUOTINO |
-				 XFS_SB_QFLAGS));
 
 		xfs_sb_version_addquota(&mp->m_sb);
 		mp->m_sb.sb_uquotino = NULLFSINO;
···
 	else
 		mp->m_sb.sb_pquotino = (*ip)->i_ino;
 	spin_unlock(&mp->m_sb_lock);
-	xfs_mod_sb(tp, sbfields);
+	xfs_log_sb(tp);
 
 	if ((error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES))) {
 		xfs_alert(mp, "%s failed (error %d)!", __func__, error);
···
 	spin_unlock(&mp->m_sb_lock);
 
 	if (sbf != (mp->m_qflags & XFS_MOUNT_QUOTA_ALL)) {
-		if (xfs_qm_write_sb_changes(mp, XFS_SB_QFLAGS)) {
+		if (xfs_sync_sb(mp, false)) {
 			/*
 			 * We could only have been turning quotas off.
 			 * We aren't in very good shape actually because
···
 	struct xfs_inode	*gip = NULL;
 	struct xfs_inode	*pip = NULL;
 	int			error;
-	__int64_t		sbflags = 0;
 	uint			flags = 0;
 
 	ASSERT(mp->m_quotainfo);
···
 		}
 	} else {
 		flags |= XFS_QMOPT_SBVERSION;
-		sbflags |= (XFS_SB_VERSIONNUM | XFS_SB_UQUOTINO |
-			    XFS_SB_GQUOTINO | XFS_SB_PQUOTINO |
-			    XFS_SB_QFLAGS);
 	}
 
 	/*
···
 	 */
 	if (XFS_IS_UQUOTA_ON(mp) && uip == NULL) {
 		error = xfs_qm_qino_alloc(mp, &uip,
-					      sbflags | XFS_SB_UQUOTINO,
 					      flags | XFS_QMOPT_UQUOTA);
 		if (error)
 			goto error_rele;
···
 	}
 	if (XFS_IS_GQUOTA_ON(mp) && gip == NULL) {
 		error = xfs_qm_qino_alloc(mp, &gip,
-					  sbflags | XFS_SB_GQUOTINO,
 					  flags | XFS_QMOPT_GQUOTA);
 		if (error)
 			goto error_rele;
···
 	}
 	if (XFS_IS_PQUOTA_ON(mp) && pip == NULL) {
 		error = xfs_qm_qino_alloc(mp, &pip,
-					  sbflags | XFS_SB_PQUOTINO,
 					  flags | XFS_QMOPT_PQUOTA);
 		if (error)
 			goto error_rele;
···
 
 	xfs_qm_dqdestroy(dqp);
 }
-
-/*
- * Start a transaction and write the incore superblock changes to
- * disk. flags parameter indicates which fields have changed.
- */
-int
-xfs_qm_write_sb_changes(
-	xfs_mount_t	*mp,
-	__int64_t	flags)
-{
-	xfs_trans_t	*tp;
-	int		error;
-
-	tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
-	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_sbchange, 0, 0);
-	if (error) {
-		xfs_trans_cancel(tp, 0);
-		return error;
-	}
-
-	xfs_mod_sb(tp, flags);
-	error = xfs_trans_commit(tp, 0);
-
-	return error;
-}
-
 
 /* --------------- utility functions for vnodeops ---------------- */
 

fs/xfs/xfs_qm.h

···
 #define XFS_QM_RTBWARNLIMIT	5
 
 extern void		xfs_qm_destroy_quotainfo(struct xfs_mount *);
-extern int		xfs_qm_write_sb_changes(struct xfs_mount *, __int64_t);
 
 /* dquot stuff */
 extern void		xfs_qm_dqpurge_all(struct xfs_mount *, uint);

fs/xfs/xfs_qm_syscalls.c

···
 		mutex_unlock(&q->qi_quotaofflock);
 
 		/* XXX what to do if error ? Revert back to old vals incore ? */
-		error = xfs_qm_write_sb_changes(mp, XFS_SB_QFLAGS);
-		return error;
+		return xfs_sync_sb(mp, false);
 	}
 
 	dqtype = 0;
···
 {
 	int		error;
 	uint		qf;
-	__int64_t	sbflags;
 
 	flags &= (XFS_ALL_QUOTA_ACCT | XFS_ALL_QUOTA_ENFD);
 	/*
 	 * Switching on quota accounting must be done at mount time.
 	 */
 	flags &= ~(XFS_ALL_QUOTA_ACCT);
-
-	sbflags = 0;
 
 	if (flags == 0) {
 		xfs_debug(mp, "%s: zero flags, m_qflags=%x",
···
 	/*
 	 * There's nothing to change if it's the same.
 	 */
-	if ((qf & flags) == flags && sbflags == 0)
+	if ((qf & flags) == flags)
 		return -EEXIST;
-	sbflags |= XFS_SB_QFLAGS;
 
-	if ((error = xfs_qm_write_sb_changes(mp, sbflags)))
+	error = xfs_sync_sb(mp, false);
+	if (error)
 		return error;
 	/*
 	 * If we aren't trying to switch on quota enforcement, we are done.
···
 	mp->m_sb.sb_qflags = (mp->m_qflags & ~(flags)) & XFS_MOUNT_QUOTA_ALL;
 	spin_unlock(&mp->m_sb_lock);
 
-	xfs_mod_sb(tp, XFS_SB_QFLAGS);
+	xfs_log_sb(tp);
 
 	/*
 	 * We have to make sure that the transaction is secure on disk before we

fs/xfs/xfs_super.c

···
 		 * If this is the first remount to writeable state we
 		 * might have some superblock changes to update.
 		 */
-		if (mp->m_update_flags) {
-			error = xfs_mount_log_sb(mp, mp->m_update_flags);
+		if (mp->m_update_sb) {
+			error = xfs_sync_sb(mp, false);
 			if (error) {
 				xfs_warn(mp, "failed to write sb changes");
 				return error;
 			}
-			mp->m_update_flags = 0;
+			mp->m_update_sb = false;
 		}
 
 		/*
···
 
 /*
  * Second stage of a freeze. The data is already frozen so we only
- * need to take care of the metadata. Once that's done write a dummy
- * record to dirty the log in case of a crash while frozen.
+ * need to take care of the metadata. Once that's done sync the superblock
+ * to the log to dirty it in case of a crash while frozen. This ensures that we
+ * will recover the unlinked inode lists on the next mount.
  */
 STATIC int
 xfs_fs_freeze(
···
 
 	xfs_save_resvblks(mp);
 	xfs_quiesce_attr(mp);
-	return xfs_fs_log_dummy(mp);
+	return xfs_sync_sb(mp, true);
 }
 
 STATIC int