xfs: convert buffer verifiers to an ops structure.

To separate the verifiers from iodone functions and associate read
and write verifiers at the same time, introduce a buffer verifier
operations structure to the xfs_buf.

This avoids the need for assigning the write verifier, clearing the
iodone function and re-running ioend processing in the read
verifier, and gets rid of the nasty "b_pre_io" name for the write
verifier function pointer. If we ever need to, it will also be
easier to add further content specific callbacks to a buffer with an
ops structure in place.

We also avoid needing to export verifier functions, instead we
can simply export the ops structures for those that are needed
outside the function they are defined in.

This patch also fixes a directory block readahead verifier issue
it exposed.

This patch also adds ops callbacks to the inode/alloc btree blocks
initialised by growfs. These will need more work before they will
work with CRCs.

Signed-off-by: Dave Chinner <[e-mail]>
Reviewed-by: Phil White <[e-mail]>
Signed-off-by: Ben Myers <[e-mail]>

fs/xfs/xfs_ag.h

···
 extern int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
 			xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
 
+extern const struct xfs_buf_ops xfs_agf_buf_ops;
+
 /*
  * Size of the unlinked inode hash table in the agi.
  */
···
 
 extern int xfs_read_agi(struct xfs_mount *mp, struct xfs_trans *tp,
 				xfs_agnumber_t agno, struct xfs_buf **bpp);
+
+extern const struct xfs_buf_ops xfs_agi_buf_ops;
 
 /*
  * The third a.g. block contains the a.g. freelist, an array

fs/xfs/xfs_alloc.c

···
 #endif
 }
 
-void
+static void
 xfs_agfl_write_verify(
 	struct xfs_buf	*bp)
 {
···
 	struct xfs_buf	*bp)
 {
 	xfs_agfl_verify(bp);
-	bp->b_pre_io = xfs_agfl_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
 }
+
+const struct xfs_buf_ops xfs_agfl_buf_ops = {
+	.verify_read = xfs_agfl_read_verify,
+	.verify_write = xfs_agfl_write_verify,
+};
 
 /*
  * Read in the allocation group free block array.
···
 	error = xfs_trans_read_buf(
 			mp, tp, mp->m_ddev_targp,
 			XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
-			XFS_FSS_TO_BB(mp, 1), 0, &bp, xfs_agfl_read_verify);
+			XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
 	if (error)
 		return error;
 	ASSERT(!xfs_buf_geterror(bp));
···
 	}
 }
 
-void
-xfs_agf_write_verify(
+static void
+xfs_agf_read_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_agf_verify(bp);
 }
 
 static void
-xfs_agf_read_verify(
+xfs_agf_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_agf_verify(bp);
-	bp->b_pre_io = xfs_agf_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
 }
+
+const struct xfs_buf_ops xfs_agf_buf_ops = {
+	.verify_read = xfs_agf_read_verify,
+	.verify_write = xfs_agf_write_verify,
+};
 
 /*
  * Read in the allocation group header (free/alloc section).
···
 	error = xfs_trans_read_buf(
 			mp, tp, mp->m_ddev_targp,
 			XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
-			XFS_FSS_TO_BB(mp, 1), flags, bpp, xfs_agf_read_verify);
+			XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
 	if (error)
 		return error;
 	if (!*bpp)

fs/xfs/xfs_alloc.h

···
 	xfs_extlen_t		*len,	/* output: length of extent */
 	int			*stat);	/* output: success/failure */
 
-void xfs_agf_write_verify(struct xfs_buf *bp);
-void xfs_agfl_write_verify(struct xfs_buf *bp);
+extern const struct xfs_buf_ops xfs_agf_buf_ops;
+extern const struct xfs_buf_ops xfs_agfl_buf_ops;
 
 #endif	/* __XFS_ALLOC_H__ */

fs/xfs/xfs_alloc_btree.c

···
 }
 
 static void
+xfs_allocbt_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_allocbt_verify(bp);
+}
+
+static void
 xfs_allocbt_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_allocbt_verify(bp);
 }
 
-void
-xfs_allocbt_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_allocbt_verify(bp);
-	bp->b_pre_io = xfs_allocbt_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
-}
+const struct xfs_buf_ops xfs_allocbt_buf_ops = {
+	.verify_read = xfs_allocbt_read_verify,
+	.verify_write = xfs_allocbt_write_verify,
+};
+
 
 #ifdef DEBUG
 STATIC int
···
 	.init_rec_from_cur	= xfs_allocbt_init_rec_from_cur,
 	.init_ptr_from_cur	= xfs_allocbt_init_ptr_from_cur,
 	.key_diff		= xfs_allocbt_key_diff,
-	.read_verify		= xfs_allocbt_read_verify,
-	.write_verify		= xfs_allocbt_write_verify,
+	.buf_ops		= &xfs_allocbt_buf_ops,
 #ifdef DEBUG
 	.keys_inorder		= xfs_allocbt_keys_inorder,
 	.recs_inorder		= xfs_allocbt_recs_inorder,

fs/xfs/xfs_alloc_btree.h

···
 		xfs_agnumber_t, xfs_btnum_t);
 extern int xfs_allocbt_maxrecs(struct xfs_mount *, int, int);
 
+extern const struct xfs_buf_ops xfs_allocbt_buf_ops;
+
 #endif	/* __XFS_ALLOC_BTREE_H__ */

fs/xfs/xfs_attr_leaf.c

···
 }
 
 static void
+xfs_attr_leaf_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_attr_leaf_verify(bp);
+}
+
+static void
 xfs_attr_leaf_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_attr_leaf_verify(bp);
 }
 
-void
-xfs_attr_leaf_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_attr_leaf_verify(bp);
-	bp->b_pre_io = xfs_attr_leaf_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
-}
-
+const struct xfs_buf_ops xfs_attr_leaf_buf_ops = {
+	.verify_read = xfs_attr_leaf_read_verify,
+	.verify_write = xfs_attr_leaf_write_verify,
+};
 
 int
 xfs_attr_leaf_read(
···
 	struct xfs_buf		**bpp)
 {
 	return xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
-				XFS_ATTR_FORK, xfs_attr_leaf_read_verify);
+				XFS_ATTR_FORK, &xfs_attr_leaf_buf_ops);
 }
 
 /*========================================================================
···
 					    XFS_ATTR_FORK);
 	if (error)
 		goto out;
-	bp2->b_pre_io = bp1->b_pre_io;
+	bp2->b_ops = bp1->b_ops;
 	memcpy(bp2->b_addr, bp1->b_addr, XFS_LBSIZE(dp->i_mount));
 	bp1 = NULL;
 	xfs_trans_log_buf(args->trans, bp2, 0, XFS_LBSIZE(dp->i_mount) - 1);
···
 					    XFS_ATTR_FORK);
 	if (error)
 		return(error);
-	bp->b_pre_io = xfs_attr_leaf_write_verify;
+	bp->b_ops = &xfs_attr_leaf_buf_ops;
 	leaf = bp->b_addr;
 	memset((char *)leaf, 0, XFS_LBSIZE(dp->i_mount));
 	hdr = &leaf->hdr;

fs/xfs/xfs_attr_leaf.h

···
 int	xfs_attr_leaf_read(struct xfs_trans *tp, struct xfs_inode *dp,
 			xfs_dablk_t bno, xfs_daddr_t mappedbno,
 			struct xfs_buf **bpp);
-void	xfs_attr_leaf_read_verify(struct xfs_buf *bp);
+
+extern const struct xfs_buf_ops xfs_attr_leaf_buf_ops;
 
 #endif	/* __XFS_ATTR_LEAF_H__ */

fs/xfs/xfs_bmap.c

···
 		return error;
 #endif
 	error = xfs_btree_read_bufl(mp, tp, cbno, 0, &cbp, XFS_BMAP_BTREE_REF,
-				xfs_bmbt_read_verify);
+				&xfs_bmbt_buf_ops);
 	if (error)
 		return error;
 	cblock = XFS_BUF_TO_BLOCK(cbp);
···
 	/*
 	 * Fill in the child block.
 	 */
-	abp->b_pre_io = xfs_bmbt_write_verify;
+	abp->b_ops = &xfs_bmbt_buf_ops;
 	ablock = XFS_BUF_TO_BLOCK(abp);
 	ablock->bb_magic = cpu_to_be32(XFS_BMAP_MAGIC);
 	ablock->bb_level = 0;
···
 		ASSERT(args.len == 1);
 		*firstblock = args.fsbno;
 		bp = xfs_btree_get_bufl(args.mp, tp, args.fsbno, 0);
-		bp->b_pre_io = xfs_bmbt_write_verify;
+		bp->b_ops = &xfs_bmbt_buf_ops;
 		memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
 		xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
 		xfs_bmap_forkoff_reset(args.mp, ip, whichfork);
···
 	 */
 	while (level-- > 0) {
 		error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
-				XFS_BMAP_BTREE_REF, xfs_bmbt_read_verify);
+				XFS_BMAP_BTREE_REF, &xfs_bmbt_buf_ops);
 		if (error)
 			return error;
 		block = XFS_BUF_TO_BLOCK(bp);
···
 		nextbno = be64_to_cpu(block->bb_u.l.bb_rightsib);
 		if (nextbno != NULLFSBLOCK)
 			xfs_btree_reada_bufl(mp, nextbno, 1,
-					     xfs_bmbt_read_verify);
+					     &xfs_bmbt_buf_ops);
 		/*
 		 * Copy records into the extent records.
 		 */
···
 		if (bno == NULLFSBLOCK)
 			break;
 		error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
-				XFS_BMAP_BTREE_REF, xfs_bmbt_read_verify);
+				XFS_BMAP_BTREE_REF, &xfs_bmbt_buf_ops);
 		if (error)
 			return error;
 		block = XFS_BUF_TO_BLOCK(bp);
···
 			bp_release = 1;
 			error = xfs_btree_read_bufl(mp, NULL, bno, 0, &bp,
 						XFS_BMAP_BTREE_REF,
-						xfs_bmbt_read_verify);
+						&xfs_bmbt_buf_ops);
 			if (error)
 				goto error_norelse;
 		}
···
 			bp_release = 1;
 			error = xfs_btree_read_bufl(mp, NULL, bno, 0, &bp,
 						XFS_BMAP_BTREE_REF,
-						xfs_bmbt_read_verify);
+						&xfs_bmbt_buf_ops);
 			if (error)
 				goto error_norelse;
 		}
···
 	int			numrecs;
 
 	error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp, XFS_BMAP_BTREE_REF,
-						xfs_bmbt_read_verify);
+						&xfs_bmbt_buf_ops);
 	if (error)
 		return error;
 	*count += 1;
···
 		while (nextbno != NULLFSBLOCK) {
 			error = xfs_btree_read_bufl(mp, tp, nextbno, 0, &nbp,
 						XFS_BMAP_BTREE_REF,
-						xfs_bmbt_read_verify);
+						&xfs_bmbt_buf_ops);
 			if (error)
 				return error;
 			*count += 1;
···
 			bno = nextbno;
 			error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
 						XFS_BMAP_BTREE_REF,
-						xfs_bmbt_read_verify);
+						&xfs_bmbt_buf_ops);
 			if (error)
 				return error;
 			*count += 1;

fs/xfs/xfs_bmap_btree.c

···
 	}
 }
 
-void
+static void
+xfs_bmbt_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_bmbt_verify(bp);
+}
+
+static void
 xfs_bmbt_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_bmbt_verify(bp);
 }
 
-void
-xfs_bmbt_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_bmbt_verify(bp);
-	bp->b_pre_io = xfs_bmbt_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
-}
+const struct xfs_buf_ops xfs_bmbt_buf_ops = {
+	.verify_read = xfs_bmbt_read_verify,
+	.verify_write = xfs_bmbt_write_verify,
+};
+
 
 #ifdef DEBUG
 STATIC int
···
 	.init_rec_from_cur	= xfs_bmbt_init_rec_from_cur,
 	.init_ptr_from_cur	= xfs_bmbt_init_ptr_from_cur,
 	.key_diff		= xfs_bmbt_key_diff,
-	.read_verify		= xfs_bmbt_read_verify,
-	.write_verify		= xfs_bmbt_write_verify,
+	.buf_ops		= &xfs_bmbt_buf_ops,
 #ifdef DEBUG
 	.keys_inorder		= xfs_bmbt_keys_inorder,
 	.recs_inorder		= xfs_bmbt_recs_inorder,

fs/xfs/xfs_bmap_btree.h

···
 extern int xfs_bmbt_get_maxrecs(struct xfs_btree_cur *, int level);
 extern int xfs_bmdr_maxrecs(struct xfs_mount *, int blocklen, int leaf);
 extern int xfs_bmbt_maxrecs(struct xfs_mount *, int blocklen, int leaf);
-extern void xfs_bmbt_read_verify(struct xfs_buf *bp);
-extern void xfs_bmbt_write_verify(struct xfs_buf *bp);
 
 extern struct xfs_btree_cur *xfs_bmbt_init_cursor(struct xfs_mount *,
 		struct xfs_trans *, struct xfs_inode *, int);
 
+extern const struct xfs_buf_ops xfs_bmbt_buf_ops;
 
 #endif	/* __XFS_BMAP_BTREE_H__ */

fs/xfs/xfs_btree.c

···
 			error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 						   XFS_BUF_ADDR(bp), mp->m_bsize,
 						   0, &bp,
-						   cur->bc_ops->read_verify);
+						   cur->bc_ops->buf_ops);
 			if (error) {
 				xfs_btree_del_cursor(new, error);
 				*ncur = NULL;
···
 	uint			lock,		/* lock flags for read_buf */
 	struct xfs_buf		**bpp,		/* buffer for fsbno */
 	int			refval,		/* ref count value for buffer */
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	struct xfs_buf		*bp;		/* return value */
 	xfs_daddr_t		d;		/* real disk block address */
···
 	ASSERT(fsbno != NULLFSBLOCK);
 	d = XFS_FSB_TO_DADDR(mp, fsbno);
 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
-				   mp->m_bsize, lock, &bp, verify);
+				   mp->m_bsize, lock, &bp, ops);
 	if (error)
 		return error;
 	ASSERT(!xfs_buf_geterror(bp));
···
 	struct xfs_mount	*mp,		/* file system mount point */
 	xfs_fsblock_t		fsbno,		/* file system block number */
 	xfs_extlen_t		count,		/* count of filesystem blocks */
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	xfs_daddr_t		d;
 
 	ASSERT(fsbno != NULLFSBLOCK);
 	d = XFS_FSB_TO_DADDR(mp, fsbno);
-	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, verify);
+	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
 }
 
 /*
···
 	xfs_agnumber_t		agno,		/* allocation group number */
 	xfs_agblock_t		agbno,		/* allocation group block number */
 	xfs_extlen_t		count,		/* count of filesystem blocks */
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	xfs_daddr_t		d;
 
 	ASSERT(agno != NULLAGNUMBER);
 	ASSERT(agbno != NULLAGBLOCK);
 	d = XFS_AGB_TO_DADDR(mp, agno, agbno);
-	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, verify);
+	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, ops);
 }
 
 STATIC int
···
 
 	if ((lr & XFS_BTCUR_LEFTRA) && left != NULLDFSBNO) {
 		xfs_btree_reada_bufl(cur->bc_mp, left, 1,
-				     cur->bc_ops->read_verify);
+				     cur->bc_ops->buf_ops);
 		rval++;
 	}
 
 	if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLDFSBNO) {
 		xfs_btree_reada_bufl(cur->bc_mp, right, 1,
-				     cur->bc_ops->read_verify);
+				     cur->bc_ops->buf_ops);
 		rval++;
 	}
 
···
 
 	if ((lr & XFS_BTCUR_LEFTRA) && left != NULLAGBLOCK) {
 		xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
-				     left, 1, cur->bc_ops->read_verify);
+				     left, 1, cur->bc_ops->buf_ops);
 		rval++;
 	}
 
 	if ((lr & XFS_BTCUR_RIGHTRA) && right != NULLAGBLOCK) {
 		xfs_btree_reada_bufs(cur->bc_mp, cur->bc_private.a.agno,
-				     right, 1, cur->bc_ops->read_verify);
+				     right, 1, cur->bc_ops->buf_ops);
 		rval++;
 	}
 
···
 	if (!*bpp)
 		return ENOMEM;
 
-	(*bpp)->b_pre_io = cur->bc_ops->write_verify;
+	(*bpp)->b_ops = cur->bc_ops->buf_ops;
 	*block = XFS_BUF_TO_BLOCK(*bpp);
 	return 0;
 }
···
 	d = xfs_btree_ptr_to_daddr(cur, ptr);
 	error = xfs_trans_read_buf(mp, cur->bc_tp, mp->m_ddev_targp, d,
 				   mp->m_bsize, flags, bpp,
-				   cur->bc_ops->read_verify);
+				   cur->bc_ops->buf_ops);
 	if (error)
 		return error;
 

fs/xfs/xfs_btree.h

···
 	__int64_t (*key_diff)(struct xfs_btree_cur *cur,
 			      union xfs_btree_key *key);
 
-	void	(*read_verify)(struct xfs_buf *bp);
-	void	(*write_verify)(struct xfs_buf *bp);
+	const struct xfs_buf_ops	*buf_ops;
 
 #ifdef DEBUG
 	/* check that k1 is lower than k2 */
···
 	uint			lock,	/* lock flags for read_buf */
 	struct xfs_buf		**bpp,	/* buffer for fsbno */
 	int			refval,	/* ref count value for buffer */
-	xfs_buf_iodone_t	verify);
+	const struct xfs_buf_ops *ops);
 
 /*
  * Read-ahead the block, don't wait for it, don't return a buffer.
···
 	struct xfs_mount	*mp,	/* file system mount point */
 	xfs_fsblock_t		fsbno,	/* file system block number */
 	xfs_extlen_t		count,	/* count of filesystem blocks */
-	xfs_buf_iodone_t	verify);
+	const struct xfs_buf_ops *ops);
 
 /*
  * Read-ahead the block, don't wait for it, don't return a buffer.
···
 	xfs_agnumber_t		agno,	/* allocation group number */
 	xfs_agblock_t		agbno,	/* allocation group block number */
 	xfs_extlen_t		count,	/* count of filesystem blocks */
-	xfs_buf_iodone_t	verify);
+	const struct xfs_buf_ops *ops);
 
 /*
  * Initialise a new btree block header

fs/xfs/xfs_buf.c

···
 		ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0);
 		ASSERT(bp->b_iodone == NULL);
 		bp->b_flags &= _XBF_KMEM | _XBF_PAGES;
-		bp->b_pre_io = NULL;
+		bp->b_ops = NULL;
 	}
 
 	trace_xfs_buf_find(bp, flags, _RET_IP_);
···
 	struct xfs_buf_map	*map,
 	int			nmaps,
 	xfs_buf_flags_t		flags,
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	struct xfs_buf		*bp;
 
···
 
 		if (!XFS_BUF_ISDONE(bp)) {
 			XFS_STATS_INC(xb_get_read);
-			bp->b_iodone = verify;
+			bp->b_ops = ops;
 			_xfs_buf_read(bp, flags);
 		} else if (flags & XBF_ASYNC) {
 			/*
···
 	struct xfs_buftarg	*target,
 	struct xfs_buf_map	*map,
 	int			nmaps,
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	if (bdi_read_congested(target->bt_bdi))
 		return;
 
 	xfs_buf_read_map(target, map, nmaps,
-		     XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, verify);
+		     XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, ops);
 }
 
 /*
···
 	xfs_daddr_t		daddr,
 	size_t			numblks,
 	int			flags,
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	struct xfs_buf		*bp;
 
···
 	bp->b_bn = daddr;
 	bp->b_maps[0].bm_bn = daddr;
 	bp->b_flags |= XBF_READ;
-	bp->b_iodone = verify;
+	bp->b_ops = ops;
 
 	xfsbdstrat(target->bt_mount, bp);
 	xfs_buf_iowait(bp);
···
 xfs_buf_iodone_work(
 	struct work_struct	*work)
 {
-	xfs_buf_t		*bp =
+	struct xfs_buf		*bp =
 		container_of(work, xfs_buf_t, b_iodone_work);
+	bool			read = !!(bp->b_flags & XBF_READ);
+
+	bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD);
+	if (read && bp->b_ops)
+		bp->b_ops->verify_read(bp);
 
 	if (bp->b_iodone)
 		(*(bp->b_iodone))(bp);
 	else if (bp->b_flags & XBF_ASYNC)
 		xfs_buf_relse(bp);
+	else {
+		ASSERT(read && bp->b_ops);
+		complete(&bp->b_iowait);
+	}
 }
 
 void
 xfs_buf_ioend(
-	xfs_buf_t		*bp,
-	int			schedule)
+	struct xfs_buf	*bp,
+	int		schedule)
 {
+	bool		read = !!(bp->b_flags & XBF_READ);
+
 	trace_xfs_buf_iodone(bp, _RET_IP_);
 
-	bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD);
 	if (bp->b_error == 0)
 		bp->b_flags |= XBF_DONE;
 
-	if ((bp->b_iodone) || (bp->b_flags & XBF_ASYNC)) {
+	if (bp->b_iodone || (read && bp->b_ops) || (bp->b_flags & XBF_ASYNC)) {
 		if (schedule) {
 			INIT_WORK(&bp->b_iodone_work, xfs_buf_iodone_work);
 			queue_work(xfslogd_workqueue, &bp->b_iodone_work);
···
 			xfs_buf_iodone_work(&bp->b_iodone_work);
 		}
 	} else {
+		bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD);
 		complete(&bp->b_iowait);
 	}
 }
···
 			rw |= REQ_FUA;
 		if (bp->b_flags & XBF_FLUSH)
 			rw |= REQ_FLUSH;
+
+		/*
+		 * Run the write verifier callback function if it exists. If
+		 * this function fails it will mark the buffer with an error and
+		 * the IO should not be dispatched.
+		 */
+		if (bp->b_ops) {
+			bp->b_ops->verify_write(bp);
+			if (bp->b_error) {
+				xfs_force_shutdown(bp->b_target->bt_mount,
+						   SHUTDOWN_CORRUPT_INCORE);
+				return;
+			}
+		}
 	} else if (bp->b_flags & XBF_READ_AHEAD) {
 		rw = READA;
 	} else {
···
 
 	/* we only use the buffer cache for meta-data */
 	rw |= REQ_META;
-
-	/*
-	 * run the pre-io callback function if it exists. If this function
-	 * fails it will mark the buffer with an error and the IO should
-	 * not be dispatched.
-	 */
-	if (bp->b_pre_io) {
-		bp->b_pre_io(bp);
-		if (bp->b_error) {
-			xfs_force_shutdown(bp->b_target->bt_mount,
-					   SHUTDOWN_CORRUPT_INCORE);
-			return;
-		}
-	}
 
 	/*
 	 * Walk all the vectors issuing IO on them. Set up the initial offset

fs/xfs/xfs_buf.h

···
 #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
 	struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
 
+struct xfs_buf_ops {
+	void (*verify_read)(struct xfs_buf *);
+	void (*verify_write)(struct xfs_buf *);
+};
+
 typedef struct xfs_buf {
 	/*
 	 * first cacheline holds all the fields needed for an uncontended cache
···
 	unsigned int		b_page_count;	/* size of page array */
 	unsigned int		b_offset;	/* page offset in first page */
 	unsigned short		b_error;	/* error code on I/O */
-
-	void			(*b_pre_io)(struct xfs_buf *);
-						/* pre-io callback function */
+	const struct xfs_buf_ops	*b_ops;
 
 #ifdef XFS_BUF_LOCK_TRACKING
 	int			b_last_holder;
···
 			       xfs_buf_flags_t flags);
 struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target,
 			       struct xfs_buf_map *map, int nmaps,
-			       xfs_buf_flags_t flags, xfs_buf_iodone_t verify);
+			       xfs_buf_flags_t flags,
+			       const struct xfs_buf_ops *ops);
 void xfs_buf_readahead_map(struct xfs_buftarg *target,
 			       struct xfs_buf_map *map, int nmaps,
-			       xfs_buf_iodone_t verify);
+			       const struct xfs_buf_ops *ops);
 
 static inline struct xfs_buf *
 xfs_buf_get(
···
 	xfs_daddr_t		blkno,
 	size_t			numblks,
 	xfs_buf_flags_t		flags,
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
-	return xfs_buf_read_map(target, &map, 1, flags, verify);
+	return xfs_buf_read_map(target, &map, 1, flags, ops);
 }
 
 static inline void
···
 	struct xfs_buftarg	*target,
 	xfs_daddr_t		blkno,
 	size_t			numblks,
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
-	return xfs_buf_readahead_map(target, &map, 1, verify);
+	return xfs_buf_readahead_map(target, &map, 1, ops);
 }
 
 struct xfs_buf *xfs_buf_get_empty(struct xfs_buftarg *target, size_t numblks);
···
 				int flags);
 struct xfs_buf *xfs_buf_read_uncached(struct xfs_buftarg *target,
 				xfs_daddr_t daddr, size_t numblks, int flags,
-				xfs_buf_iodone_t verify);
+				const struct xfs_buf_ops *ops);
 void xfs_buf_hold(struct xfs_buf *bp);
 
 /* Releasing Buffers */

fs/xfs/xfs_da_btree.c

···
 	xfs_da_node_verify(bp);
 }
 
+/*
+ * leaf/node format detection on trees is sketchy, so a node read can be done on
+ * leaf level blocks when detection identifies the tree as a node format tree
+ * incorrectly. In this case, we need to swap the verifier to match the correct
+ * format of the block being read.
+ */
 static void
 xfs_da_node_read_verify(
 	struct xfs_buf		*bp)
···
 			xfs_da_node_verify(bp);
 			break;
 		case XFS_ATTR_LEAF_MAGIC:
-			xfs_attr_leaf_read_verify(bp);
+			bp->b_ops = &xfs_attr_leaf_buf_ops;
+			bp->b_ops->verify_read(bp);
 			return;
 		case XFS_DIR2_LEAFN_MAGIC:
-			xfs_dir2_leafn_read_verify(bp);
+			bp->b_ops = &xfs_dir2_leafn_buf_ops;
+			bp->b_ops->verify_read(bp);
 			return;
 		default:
 			XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW,
···
 			xfs_buf_ioerror(bp, EFSCORRUPTED);
 			break;
 	}
-
-	bp->b_pre_io = xfs_da_node_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
 }
+
+const struct xfs_buf_ops xfs_da_node_buf_ops = {
+	.verify_read = xfs_da_node_read_verify,
+	.verify_write = xfs_da_node_write_verify,
+};
+
 
 int
 xfs_da_node_read(
···
 	int			which_fork)
 {
 	return xfs_da_read_buf(tp, dp, bno, mappedbno, bpp,
-					which_fork, xfs_da_node_read_verify);
+					which_fork, &xfs_da_node_buf_ops);
 }
 
 /*========================================================================
···
 	xfs_trans_log_buf(tp, bp,
 		XFS_DA_LOGRANGE(node, &node->hdr, sizeof(node->hdr)));
 
-	bp->b_pre_io = xfs_da_node_write_verify;
+	bp->b_ops = &xfs_da_node_buf_ops;
 	*bpp = bp;
 	return(0);
 }
···
 	memcpy(node, oldroot, size);
 	xfs_trans_log_buf(tp, bp, 0, size - 1);
 
-	bp->b_pre_io = blk1->bp->b_pre_io;
+	bp->b_ops = blk1->bp->b_ops;
 	blk1->bp = bp;
 	blk1->blkno = blkno;
 
···
 	/*
 	 * This could be copying a leaf back into the root block in the case of
 	 * there only being a single leaf block left in the tree. Hence we have
-	 * to update the pre_io pointer as well to match the buffer type change
+	 * to update the b_ops pointer as well to match the buffer type change
 	 * that could occur.
 	 */
 	memcpy(root_blk->bp->b_addr, bp->b_addr, state->blocksize);
-	root_blk->bp->b_pre_io = bp->b_pre_io;
+	root_blk->bp->b_ops = bp->b_ops;
 	xfs_trans_log_buf(args->trans, root_blk->bp, 0, state->blocksize - 1);
 	error = xfs_da_shrink_inode(args, child, bp);
 	return(error);
···
 	xfs_daddr_t		mappedbno,
 	struct xfs_buf		**bpp,
 	int			whichfork,
-	xfs_buf_iodone_t	verifier)
+	const struct xfs_buf_ops *ops)
 {
 	struct xfs_buf		*bp;
 	struct xfs_buf_map	map;
···
 
 	error = xfs_trans_read_buf_map(dp->i_mount, trans,
 					dp->i_mount->m_ddev_targp,
-					mapp, nmap, 0, &bp, verifier);
+					mapp, nmap, 0, &bp, ops);
 	if (error)
 		goto out_free;
 
···
 	xfs_dablk_t		bno,
 	xfs_daddr_t		mappedbno,
 	int			whichfork,
-	xfs_buf_iodone_t	verifier)
+	const struct xfs_buf_ops *ops)
 {
 	struct xfs_buf_map	map;
 	struct xfs_buf_map	*mapp;
···
 	}
 
 	mappedbno = mapp[0].bm_bn;
-	xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, NULL);
+	xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, ops);
 
 out_free:
 	if (mapp != &map)

fs/xfs/xfs_da_btree.h

···
 int	xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 			       xfs_dablk_t bno, xfs_daddr_t mappedbno,
 			       struct xfs_buf **bpp, int whichfork,
-			       xfs_buf_iodone_t verifier);
+			       const struct xfs_buf_ops *ops);
 xfs_daddr_t	xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 				xfs_dablk_t bno, xfs_daddr_t mapped_bno,
-				int whichfork, xfs_buf_iodone_t verifier);
+				int whichfork, const struct xfs_buf_ops *ops);
 int	xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
 					  struct xfs_buf *dead_buf);
 

fs/xfs/xfs_dir2_block.c

···
 }
 
 static void
+xfs_dir2_block_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_dir2_block_verify(bp);
+}
+
+static void
 xfs_dir2_block_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_dir2_block_verify(bp);
 }
 
-void
-xfs_dir2_block_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_dir2_block_verify(bp);
-	bp->b_pre_io = xfs_dir2_block_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
-}
+const struct xfs_buf_ops xfs_dir2_block_buf_ops = {
+	.verify_read = xfs_dir2_block_read_verify,
+	.verify_write = xfs_dir2_block_write_verify,
+};
 
 static int
 xfs_dir2_block_read(
···
 	struct xfs_mount	*mp = dp->i_mount;
 
 	return xfs_da_read_buf(tp, dp, mp->m_dirdatablk, -1, bpp,
-				XFS_DATA_FORK, xfs_dir2_block_read_verify);
+				XFS_DATA_FORK, &xfs_dir2_block_buf_ops);
 }
 
 static void
···
 	/*
 	 * Start converting it to block form.
 	 */
-	dbp->b_pre_io = xfs_dir2_block_write_verify;
+	dbp->b_ops = &xfs_dir2_block_buf_ops;
 	hdr->magic = cpu_to_be32(XFS_DIR2_BLOCK_MAGIC);
 	needlog = 1;
 	needscan = 0;
···
 		kmem_free(sfp);
 		return error;
 	}
-	bp->b_pre_io = xfs_dir2_block_write_verify;
+	bp->b_ops = &xfs_dir2_block_buf_ops;
 	hdr = bp->b_addr;
 	hdr->magic = cpu_to_be32(XFS_DIR2_BLOCK_MAGIC);
 	/*

fs/xfs/xfs_dir2_data.c

···
 	}
 }
 
-void
-xfs_dir2_data_write_verify(
-	struct xfs_buf	*bp)
+/*
+ * Readahead of the first block of the directory when it is opened is completely
+ * oblivious to the format of the directory. Hence we can either get a block
+ * format buffer or a data format buffer on readahead.
+ */
+static void
+xfs_dir2_data_reada_verify(
+	struct xfs_buf		*bp)
 {
-	xfs_dir2_data_verify(bp);
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_dir2_data_hdr *hdr = bp->b_addr;
+
+	switch (hdr->magic) {
+	case cpu_to_be32(XFS_DIR2_BLOCK_MAGIC):
+		bp->b_ops = &xfs_dir2_block_buf_ops;
+		bp->b_ops->verify_read(bp);
+		return;
+	case cpu_to_be32(XFS_DIR2_DATA_MAGIC):
+		xfs_dir2_data_verify(bp);
+		return;
+	default:
+		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, hdr);
+		xfs_buf_ioerror(bp, EFSCORRUPTED);
+		break;
+	}
 }
 
 static void
···
 	struct xfs_buf	*bp)
 {
 	xfs_dir2_data_verify(bp);
-	bp->b_pre_io = xfs_dir2_data_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
 }
+
+static void
+xfs_dir2_data_write_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_dir2_data_verify(bp);
+}
+
+const struct xfs_buf_ops xfs_dir2_data_buf_ops = {
+	.verify_read = xfs_dir2_data_read_verify,
+	.verify_write = xfs_dir2_data_write_verify,
+};
+
+static const struct xfs_buf_ops xfs_dir2_data_reada_buf_ops = {
+	.verify_read = xfs_dir2_data_reada_verify,
+	.verify_write = xfs_dir2_data_write_verify,
+};
 
 
 int
···
 	struct xfs_buf		**bpp)
 {
 	return xfs_da_read_buf(tp, dp, bno, mapped_bno, bpp,
-				XFS_DATA_FORK, xfs_dir2_data_read_verify);
+				XFS_DATA_FORK, &xfs_dir2_data_buf_ops);
 }
 
 int
···
 	xfs_daddr_t		mapped_bno)
 {
 	return xfs_da_reada_buf(tp, dp, bno, mapped_bno,
-				XFS_DATA_FORK, xfs_dir2_data_read_verify);
+				XFS_DATA_FORK, &xfs_dir2_data_reada_buf_ops);
 }
 
 /*
···
 		XFS_DATA_FORK);
 	if (error)
 		return error;
-	bp->b_pre_io = xfs_dir2_data_write_verify;
+	bp->b_ops = &xfs_dir2_data_buf_ops;
 
 	/*
 	 * Initialize the header.

fs/xfs/xfs_dir2_leaf.c

···
 }
 
 static void
-xfs_dir2_leaf1_write_verify(
+xfs_dir2_leaf1_read_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_dir2_leaf_verify(bp, cpu_to_be16(XFS_DIR2_LEAF1_MAGIC));
 }
 
 static void
-xfs_dir2_leaf1_read_verify(
+xfs_dir2_leaf1_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_dir2_leaf_verify(bp, cpu_to_be16(XFS_DIR2_LEAF1_MAGIC));
-	bp->b_pre_io = xfs_dir2_leaf1_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
+}
+
+void
+xfs_dir2_leafn_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_dir2_leaf_verify(bp, cpu_to_be16(XFS_DIR2_LEAFN_MAGIC));
 }
 
 void
···
 	xfs_dir2_leaf_verify(bp, cpu_to_be16(XFS_DIR2_LEAFN_MAGIC));
 }
 
-void
-xfs_dir2_leafn_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_dir2_leaf_verify(bp, cpu_to_be16(XFS_DIR2_LEAFN_MAGIC));
-	bp->b_pre_io = xfs_dir2_leafn_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
-}
+static const struct xfs_buf_ops xfs_dir2_leaf1_buf_ops = {
+	.verify_read = xfs_dir2_leaf1_read_verify,
+	.verify_write = xfs_dir2_leaf1_write_verify,
+};
+
+const struct xfs_buf_ops xfs_dir2_leafn_buf_ops = {
+	.verify_read = xfs_dir2_leafn_read_verify,
+	.verify_write = xfs_dir2_leafn_write_verify,
+};
 
 static int
 xfs_dir2_leaf_read(
···
 	struct xfs_buf		**bpp)
 {
 	return xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp,
-				XFS_DATA_FORK, xfs_dir2_leaf1_read_verify);
+				XFS_DATA_FORK, &xfs_dir2_leaf1_buf_ops);
 }
 
 int
···
 	struct xfs_buf		**bpp)
 {
 	return xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp,
-				XFS_DATA_FORK, xfs_dir2_leafn_read_verify);
+				XFS_DATA_FORK, &xfs_dir2_leafn_buf_ops);
 }
 
 /*
···
 	/*
 	 * Fix up the block header, make it a data block.
 	 */
-	dbp->b_pre_io = xfs_dir2_data_write_verify;
+	dbp->b_ops = &xfs_dir2_data_buf_ops;
 	hdr->magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
 	if (needscan)
 		xfs_dir2_data_freescan(mp, hdr, &needlog);
···
 	 * the block.
 	 */
 	if (magic == XFS_DIR2_LEAF1_MAGIC) {
-		bp->b_pre_io = xfs_dir2_leaf1_write_verify;
+		bp->b_ops = &xfs_dir2_leaf1_buf_ops;
 		ltp = xfs_dir2_leaf_tail_p(mp, leaf);
 		ltp->bestcount = 0;
 		xfs_dir2_leaf_log_tail(tp, bp);
 	} else
-		bp->b_pre_io = xfs_dir2_leafn_write_verify;
+		bp->b_ops = &xfs_dir2_leafn_buf_ops;
 	*bpp = bp;
 	return 0;
 }
···
 	else
 		xfs_dir2_leaf_log_header(tp, lbp);
 
-	lbp->b_pre_io = xfs_dir2_leaf1_write_verify;
+	lbp->b_ops = &xfs_dir2_leaf1_buf_ops;
 	leaf->hdr.info.magic = cpu_to_be16(XFS_DIR2_LEAF1_MAGIC);
 
 	/*

fs/xfs/xfs_dir2_node.c

···
 }
 
 static void
+xfs_dir2_free_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_dir2_free_verify(bp);
+}
+
+static void
 xfs_dir2_free_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_dir2_free_verify(bp);
 }
 
-void
-xfs_dir2_free_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_dir2_free_verify(bp);
-	bp->b_pre_io = xfs_dir2_free_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
-}
+static const struct xfs_buf_ops xfs_dir2_free_buf_ops = {
+	.verify_read = xfs_dir2_free_read_verify,
+	.verify_write = xfs_dir2_free_write_verify,
+};
 
 
 static int
···
 	struct xfs_buf		**bpp)
 {
 	return xfs_da_read_buf(tp, dp, fbno, mappedbno, bpp,
-				XFS_DATA_FORK, xfs_dir2_free_read_verify);
+				XFS_DATA_FORK, &xfs_dir2_free_buf_ops);
 }
 
 int
···
 				XFS_DATA_FORK);
 	if (error)
 		return error;
-	fbp->b_pre_io = xfs_dir2_free_write_verify;
+	fbp->b_ops = &xfs_dir2_free_buf_ops;
 
 	free = fbp->b_addr;
 	leaf = lbp->b_addr;
···
 	}
 	free->hdr.nused = cpu_to_be32(n);
 
-	lbp->b_pre_io = xfs_dir2_leafn_write_verify;
+	lbp->b_ops = &xfs_dir2_leafn_buf_ops;
 	leaf->hdr.info.magic = cpu_to_be16(XFS_DIR2_LEAFN_MAGIC);
 
 	/*
···
 			state->extrablk.index = (int)((char *)dep -
 							(char *)curbp->b_addr);
 			state->extrablk.magic = XFS_DIR2_DATA_MAGIC;
-			curbp->b_pre_io = xfs_dir2_data_write_verify;
+			curbp->b_ops = &xfs_dir2_data_buf_ops;
 			if (cmp == XFS_CMP_EXACT)
 				return XFS_ERROR(EEXIST);
 		}
···
 			state->extrablk.index = -1;
 			state->extrablk.blkno = curdb;
 			state->extrablk.magic = XFS_DIR2_DATA_MAGIC;
-			curbp->b_pre_io = xfs_dir2_data_write_verify;
+			curbp->b_ops = &xfs_dir2_data_buf_ops;
 		} else {
 			/* If the curbp is not the CI match block, drop it */
 			if (state->extrablk.bp != curbp)
···
 					       -1, &fbp, XFS_DATA_FORK);
 			if (error)
 				return error;
-			fbp->b_pre_io = xfs_dir2_free_write_verify;
+			fbp->b_ops = &xfs_dir2_free_buf_ops;
 
 			/*
 			 * Initialize the new block to be empty, and remember

fs/xfs/xfs_dir2_priv.h

···
 				const unsigned char *name, int len);
 
 /* xfs_dir2_block.c */
+extern const struct xfs_buf_ops xfs_dir2_block_buf_ops;
+
 extern int xfs_dir2_block_addname(struct xfs_da_args *args);
 extern int xfs_dir2_block_getdents(struct xfs_inode *dp, void *dirent,
 		xfs_off_t *offset, filldir_t filldir);
···
 #else
 #define	xfs_dir2_data_check(dp,bp)
 #endif
-extern void xfs_dir2_data_write_verify(struct xfs_buf *bp);
+
+extern const struct xfs_buf_ops xfs_dir2_data_buf_ops;
+
 extern int __xfs_dir2_data_check(struct xfs_inode *dp, struct xfs_buf *bp);
 extern int xfs_dir2_data_read(struct xfs_trans *tp, struct xfs_inode *dp,
 		xfs_dablk_t bno, xfs_daddr_t mapped_bno, struct xfs_buf **bpp);
···
 		xfs_dir2_data_aoff_t len, int *needlogp, int *needscanp);
 
 /* xfs_dir2_leaf.c */
-extern void xfs_dir2_leafn_read_verify(struct xfs_buf *bp);
-extern void xfs_dir2_leafn_write_verify(struct xfs_buf *bp);
+extern const struct xfs_buf_ops xfs_dir2_leafn_buf_ops;
+
 extern int xfs_dir2_leafn_read(struct xfs_trans *tp, struct xfs_inode *dp,
 		xfs_dablk_t fbno, xfs_daddr_t mappedbno, struct xfs_buf **bpp);
 extern int xfs_dir2_block_to_leaf(struct xfs_da_args *args,

fs/xfs/xfs_dquot.c

···
 }
 
 static void
-xfs_dquot_buf_write_verify(
+xfs_dquot_buf_read_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_dquot_buf_verify(bp);
 }
 
 void
-xfs_dquot_buf_read_verify(
+xfs_dquot_buf_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_dquot_buf_verify(bp);
-	bp->b_pre_io = xfs_dquot_buf_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
 }
+
+const struct xfs_buf_ops xfs_dquot_buf_ops = {
+	.verify_read = xfs_dquot_buf_read_verify,
+	.verify_write = xfs_dquot_buf_write_verify,
+};
 
 /*
  * Allocate a block and fill it with dquots.
···
 	error = xfs_buf_geterror(bp);
 	if (error)
 		goto error1;
-	bp->b_pre_io = xfs_dquot_buf_write_verify;
+	bp->b_ops = &xfs_dquot_buf_ops;
 
 	/*
 	 * Make a chunk of dquots out of this buffer and log
···
 		ASSERT(*bpp == NULL);
 		return XFS_ERROR(error);
 	}
-	(*bpp)->b_pre_io = xfs_dquot_buf_write_verify;
+	(*bpp)->b_ops = &xfs_dquot_buf_ops;
 
 	ASSERT(xfs_buf_islocked(*bpp));
 	d = (struct xfs_dqblk *)(*bpp)->b_addr;
···
 		error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 					   dqp->q_blkno,
 					   mp->m_quotainfo->qi_dqchunklen,
-					   0, &bp, xfs_dquot_buf_read_verify);
+					   0, &bp, &xfs_dquot_buf_ops);
 
 		if (error == EFSCORRUPTED && (flags & XFS_QMOPT_DQREPAIR)) {
 			xfs_dqid_t firstid = (xfs_dqid_t)map.br_startoff *

fs/xfs/xfs_dquot.h

···
 
 extern int		xfs_qm_dqread(struct xfs_mount *, xfs_dqid_t, uint,
 					uint, struct xfs_dquot	**);
-extern void		xfs_dquot_buf_read_verify(struct xfs_buf *bp);
 extern void		xfs_qm_dqdestroy(xfs_dquot_t *);
 extern int		xfs_qm_dqflush(struct xfs_dquot *, struct xfs_buf **);
 extern void		xfs_qm_dqunpin_wait(xfs_dquot_t *);
···
 	xfs_dqunlock(dqp);
 	return dqp;
 }
+
+extern const struct xfs_buf_ops xfs_dquot_buf_ops;
 
 #endif /* __XFS_DQUOT_H__ */

fs/xfs/xfs_fsops.c

···
 	struct xfs_mount	*mp,
 	xfs_daddr_t		blkno,
 	size_t			numblks,
-	int			flags)
+	int			flags,
+	const struct xfs_buf_ops *ops)
 {
 	struct xfs_buf		*bp;
 
···
 	xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
 	bp->b_bn = blkno;
 	bp->b_maps[0].bm_bn = blkno;
+	bp->b_ops = ops;
 
 	return bp;
 }
···
 		 */
 		bp = xfs_growfs_get_hdr_buf(mp,
 				XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
-				XFS_FSS_TO_BB(mp, 1), 0);
+				XFS_FSS_TO_BB(mp, 1), 0,
+				&xfs_agf_buf_ops);
 		if (!bp) {
 			error = ENOMEM;
 			goto error0;
 		}
-		bp->b_pre_io = xfs_agf_write_verify;
 
 		agf = XFS_BUF_TO_AGF(bp);
 		agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
···
 		 */
 		bp = xfs_growfs_get_hdr_buf(mp,
 				XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
-				XFS_FSS_TO_BB(mp, 1), 0);
+				XFS_FSS_TO_BB(mp, 1), 0,
+				&xfs_agfl_buf_ops);
 		if (!bp) {
 			error = ENOMEM;
 			goto error0;
 		}
-		bp->b_pre_io = xfs_agfl_write_verify;
 
 		agfl = XFS_BUF_TO_AGFL(bp);
 		for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++)
···
 		 */
 		bp = xfs_growfs_get_hdr_buf(mp,
 				XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
-				XFS_FSS_TO_BB(mp, 1), 0);
+				XFS_FSS_TO_BB(mp, 1), 0,
+				&xfs_agi_buf_ops);
 		if (!bp) {
 			error = ENOMEM;
 			goto error0;
 		}
-		bp->b_pre_io = xfs_agi_write_verify;
 
 		agi = XFS_BUF_TO_AGI(bp);
 		agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
···
 		 */
 		bp = xfs_growfs_get_hdr_buf(mp,
 				XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
-				BTOBB(mp->m_sb.sb_blocksize), 0);
+				BTOBB(mp->m_sb.sb_blocksize), 0,
+				&xfs_allocbt_buf_ops);
 
 		if (!bp) {
 			error = ENOMEM;
···
 		 */
 		bp = xfs_growfs_get_hdr_buf(mp,
 				XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
-				BTOBB(mp->m_sb.sb_blocksize), 0);
+				BTOBB(mp->m_sb.sb_blocksize), 0,
+				&xfs_allocbt_buf_ops);
 		if (!bp) {
 			error = ENOMEM;
 			goto error0;
···
 		 */
 		bp = xfs_growfs_get_hdr_buf(mp,
 				XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
-				BTOBB(mp->m_sb.sb_blocksize), 0);
+				BTOBB(mp->m_sb.sb_blocksize), 0,
+				&xfs_inobt_buf_ops);
 		if (!bp) {
 			error = ENOMEM;
 			goto error0;
···
 			error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
 				  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
 				  XFS_FSS_TO_BB(mp, 1), 0, &bp,
-				  xfs_sb_read_verify);
+				  &xfs_sb_buf_ops);
 		} else {
 			bp = xfs_trans_get_buf(NULL, mp->m_ddev_targp,
 				  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
 				  XFS_FSS_TO_BB(mp, 1), 0);
 			if (bp) {
+				bp->b_ops = &xfs_sb_buf_ops;
 				xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
-				bp->b_pre_io = xfs_sb_write_verify;
 			} else
 				error = ENOMEM;
 		}

fs/xfs/xfs_ialloc.c

···
 		 *	to log a whole cluster of inodes instead of all the
 		 *	individual transactions causing a lot of log traffic.
 		 */
-		fbuf->b_pre_io = xfs_inode_buf_write_verify;
+		fbuf->b_ops = &xfs_inode_buf_ops;
 		xfs_buf_zero(fbuf, 0, ninodes << mp->m_sb.sb_inodelog);
 		for (i = 0; i < ninodes; i++) {
 			int	ioffset = i << mp->m_sb.sb_inodelog;
···
 	xfs_check_agi_unlinked(agi);
 }
 
-void
-xfs_agi_write_verify(
+static void
+xfs_agi_read_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_agi_verify(bp);
 }
 
 static void
-xfs_agi_read_verify(
+xfs_agi_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_agi_verify(bp);
-	bp->b_pre_io = xfs_agi_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
 }
+
+const struct xfs_buf_ops xfs_agi_buf_ops = {
+	.verify_read = xfs_agi_read_verify,
+	.verify_write = xfs_agi_write_verify,
+};
 
 /*
  * Read in the allocation group header (inode allocation section)
···
 
 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 			XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
-			XFS_FSS_TO_BB(mp, 1), 0, bpp, xfs_agi_read_verify);
+			XFS_FSS_TO_BB(mp, 1), 0, bpp, &xfs_agi_buf_ops);
 	if (error)
 		return error;
 

fs/xfs/xfs_ialloc.h

···
 int xfs_inobt_get_rec(struct xfs_btree_cur *cur,
 		xfs_inobt_rec_incore_t *rec, int *stat);
 
-void xfs_agi_write_verify(struct xfs_buf *bp);
+extern const struct xfs_buf_ops xfs_agi_buf_ops;
 
 #endif	/* __XFS_IALLOC_H__ */

fs/xfs/xfs_ialloc_btree.c

···
 }
 
 static void
+xfs_inobt_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inobt_verify(bp);
+}
+
+static void
 xfs_inobt_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_inobt_verify(bp);
 }
 
-void
-xfs_inobt_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_inobt_verify(bp);
-	bp->b_pre_io = xfs_inobt_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
-}
+const struct xfs_buf_ops xfs_inobt_buf_ops = {
+	.verify_read = xfs_inobt_read_verify,
+	.verify_write = xfs_inobt_write_verify,
+};
 
 #ifdef DEBUG
 STATIC int
···
 	.init_rec_from_cur	= xfs_inobt_init_rec_from_cur,
 	.init_ptr_from_cur	= xfs_inobt_init_ptr_from_cur,
 	.key_diff		= xfs_inobt_key_diff,
-	.read_verify		= xfs_inobt_read_verify,
-	.write_verify		= xfs_inobt_write_verify,
+	.buf_ops		= &xfs_inobt_buf_ops,
 #ifdef DEBUG
 	.keys_inorder		= xfs_inobt_keys_inorder,
 	.recs_inorder		= xfs_inobt_recs_inorder,

fs/xfs/xfs_ialloc_btree.h

···
 		struct xfs_trans *, struct xfs_buf *, xfs_agnumber_t);
 extern int xfs_inobt_maxrecs(struct xfs_mount *, int, int);
 
+extern const struct xfs_buf_ops xfs_inobt_buf_ops;
+
 #endif	/* __XFS_IALLOC_BTREE_H__ */

fs/xfs/xfs_inode.c

···
 	xfs_inobp_check(mp, bp);
 }
 
-void
+
+static void
+xfs_inode_buf_read_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_inode_buf_verify(bp);
+}
+
+static void
 xfs_inode_buf_write_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_inode_buf_verify(bp);
 }
 
-void
-xfs_inode_buf_read_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_inode_buf_verify(bp);
-	bp->b_pre_io = xfs_inode_buf_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
-}
+const struct xfs_buf_ops xfs_inode_buf_ops = {
+	.verify_read = xfs_inode_buf_read_verify,
+	.verify_write = xfs_inode_buf_write_verify,
+};
+
 
 /*
  * This routine is called to map an inode to the buffer containing the on-disk
···
 	buf_flags |= XBF_UNMAPPED;
 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap->im_blkno,
 				   (int)imap->im_len, buf_flags, &bp,
-				   xfs_inode_buf_read_verify);
+				   &xfs_inode_buf_ops);
 	if (error) {
 		if (error == EAGAIN) {
 			ASSERT(buf_flags & XBF_TRYLOCK);
···
 		 * want it to fail. We can acheive this by adding a write
 		 * verifier to the buffer.
 		 */
-		 bp->b_pre_io = xfs_inode_buf_write_verify;
+		 bp->b_ops = &xfs_inode_buf_ops;
 
 		/*
 		 * Walk the inodes already attached to the buffer and mark them

fs/xfs/xfs_inode.h

···
 			       struct xfs_buf **, uint, uint);
 int		xfs_iread(struct xfs_mount *, struct xfs_trans *,
 			  struct xfs_inode *, uint);
-void		xfs_inode_buf_read_verify(struct xfs_buf *);
-void		xfs_inode_buf_write_verify(struct xfs_buf *);
 void		xfs_dinode_to_disk(struct xfs_dinode *,
 				   struct xfs_icdinode *);
 void		xfs_idestroy_fork(struct xfs_inode *, int);
···
 extern struct kmem_zone	*xfs_ifork_zone;
 extern struct kmem_zone	*xfs_inode_zone;
 extern struct kmem_zone	*xfs_ili_zone;
+extern const struct xfs_buf_ops xfs_inode_buf_ops;
 
 #endif	/* __XFS_INODE_H__ */

fs/xfs/xfs_itable.c

···
 							& ~r.ir_free)
 						xfs_btree_reada_bufs(mp, agno,
 							agbno, nbcluster,
-							xfs_inode_buf_read_verify);
+							&xfs_inode_buf_ops);
 				}
 				irbp->ir_startino = r.ir_startino;
 				irbp->ir_freecount = r.ir_freecount;

fs/xfs/xfs_log_recover.c

···
 	ASSERT(!(XFS_BUF_ISWRITE(bp)));
 	XFS_BUF_READ(bp);
 	XFS_BUF_UNASYNC(bp);
-	bp->b_iodone = xfs_sb_read_verify;
+	bp->b_ops = &xfs_sb_buf_ops;
 	xfsbdstrat(log->l_mp, bp);
 	error = xfs_buf_iowait(bp);
 	if (error) {

fs/xfs/xfs_mount.c

···
 		xfs_buf_ioerror(bp, error);
 }
 
-void
-xfs_sb_write_verify(
-	struct xfs_buf	*bp)
-{
-	xfs_sb_verify(bp);
-}
-
-void
+static void
 xfs_sb_read_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_sb_verify(bp);
-	bp->b_pre_io = xfs_sb_write_verify;
-	bp->b_iodone = NULL;
-	xfs_buf_ioend(bp, 0);
 }
 
 /*
···
  * If we find an XFS superblock, the run a normal, noisy mount because we are
  * really going to mount it and want to know about errors.
  */
-void
+static void
 xfs_sb_quiet_read_verify(
 	struct xfs_buf	*bp)
 {
···
 	/* quietly fail */
 	xfs_buf_ioerror(bp, EFSCORRUPTED);
 }
+
+static void
+xfs_sb_write_verify(
+	struct xfs_buf	*bp)
+{
+	xfs_sb_verify(bp);
+}
+
+const struct xfs_buf_ops xfs_sb_buf_ops = {
+	.verify_read = xfs_sb_read_verify,
+	.verify_write = xfs_sb_write_verify,
+};
+
+static const struct xfs_buf_ops xfs_sb_quiet_buf_ops = {
+	.verify_read = xfs_sb_quiet_read_verify,
+	.verify_write = xfs_sb_write_verify,
+};
 
 /*
  * xfs_readsb
···
 reread:
 	bp = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR,
 				   BTOBB(sector_size), 0,
-				   loud ? xfs_sb_read_verify
-				        : xfs_sb_quiet_read_verify);
+				   loud ? &xfs_sb_buf_ops
+				        : &xfs_sb_quiet_buf_ops);
 	if (!bp) {
 		if (loud)
 			xfs_warn(mp, "SB buffer read failed");

fs/xfs/xfs_mount.h

···
 
 #endif	/* __KERNEL__ */
 
-extern void	xfs_sb_read_verify(struct xfs_buf *);
-extern void	xfs_sb_write_verify(struct xfs_buf *bp);
 extern void	xfs_mod_sb(struct xfs_trans *, __int64_t);
 extern int	xfs_initialize_perag(struct xfs_mount *, xfs_agnumber_t,
 					xfs_agnumber_t *);
 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 const struct xfs_buf_ops xfs_sb_buf_ops;
 
 #endif	/* __XFS_MOUNT_H__ */

fs/xfs/xfs_qm.c

···
 		error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
 			      XFS_FSB_TO_DADDR(mp, bno),
 			      mp->m_quotainfo->qi_dqchunklen, 0, &bp,
-			      xfs_dquot_buf_read_verify);
+			      &xfs_dquot_buf_ops);
 		if (error)
 			break;
 

fs/xfs/xfs_trans.h

···
 				       struct xfs_buf_map *map, int nmaps,
 				       xfs_buf_flags_t flags,
 				       struct xfs_buf **bpp,
-				       xfs_buf_iodone_t verify);
+				       const struct xfs_buf_ops *ops);
 
 static inline int
 xfs_trans_read_buf(
···
 	int			numblks,
 	xfs_buf_flags_t		flags,
 	struct xfs_buf		**bpp,
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
 	return xfs_trans_read_buf_map(mp, tp, target, &map, 1,
-				      flags, bpp, verify);
+				      flags, bpp, ops);
 }
 
 struct xfs_buf	*xfs_trans_getsb(xfs_trans_t *, struct xfs_mount *, int);

fs/xfs/xfs_trans_buf.c

···
 	int			nmaps,
 	xfs_buf_flags_t		flags,
 	struct xfs_buf		**bpp,
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	xfs_buf_t		*bp;
 	xfs_buf_log_item_t	*bip;
···
 
 	*bpp = NULL;
 	if (!tp) {
-		bp = xfs_buf_read_map(target, map, nmaps, flags, verify);
+		bp = xfs_buf_read_map(target, map, nmaps, flags, ops);
 		if (!bp)
 			return (flags & XBF_TRYLOCK) ?
 					EAGAIN : XFS_ERROR(ENOMEM);
···
 			ASSERT(!XFS_BUF_ISASYNC(bp));
 			ASSERT(bp->b_iodone == NULL);
 			XFS_BUF_READ(bp);
-			bp->b_iodone = verify;
+			bp->b_ops = ops;
 			xfsbdstrat(tp->t_mountp, bp);
 			error = xfs_buf_iowait(bp);
 			if (error) {
···
 		return 0;
 	}
 
-	bp = xfs_buf_read_map(target, map, nmaps, flags, verify);
+	bp = xfs_buf_read_map(target, map, nmaps, flags, ops);
 	if (bp == NULL) {
 		*bpp = NULL;
 		return (flags & XBF_TRYLOCK) ?