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 <dchinner@redhat.com>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

37 files changed, 357 insertions, 249 deletions

diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h
index 22bd4db011c..f2aeedb6a57 100644
--- a/fs/xfs/xfs_ag.h
+++ b/fs/xfs/xfs_ag.h
@@ -108,6 +108,8 @@ typedef struct xfs_agf {
 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.
  */
@@ -161,6 +163,8 @@ typedef struct xfs_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
  * of block pointers to blocks owned by the allocation btree code.
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 545a6c4c236..393055fe3ae 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -465,7 +465,7 @@ xfs_agfl_verify(
 #endif
 }
 
-void
+static void
 xfs_agfl_write_verify(
 	struct xfs_buf	*bp)
 {
@@ -477,11 +477,13 @@ xfs_agfl_read_verify(
 	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.
  */
@@ -499,7 +501,7 @@ xfs_alloc_read_agfl(
 	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));
@@ -2181,23 +2183,25 @@ xfs_agf_verify(
 	}
 }
 
-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).
  */
@@ -2215,7 +2219,7 @@ xfs_read_agf(
 	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)
diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h
index f32811f50f4..99d0a610155 100644
--- a/fs/xfs/xfs_alloc.h
+++ b/fs/xfs/xfs_alloc.h
@@ -231,7 +231,7 @@ xfs_alloc_get_rec(
 	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__ */
diff --git a/fs/xfs/xfs_alloc_btree.c b/fs/xfs/xfs_alloc_btree.c
index b8339652491..b1ddef6b268 100644
--- a/fs/xfs/xfs_alloc_btree.c
+++ b/fs/xfs/xfs_alloc_btree.c
@@ -329,22 +329,25 @@ xfs_allocbt_verify(
 }
 
 static void
-xfs_allocbt_write_verify(
+xfs_allocbt_read_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_allocbt_verify(bp);
 }
 
-void
-xfs_allocbt_read_verify(
+static void
+xfs_allocbt_write_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
 xfs_allocbt_keys_inorder(
@@ -400,8 +403,7 @@ static const struct xfs_btree_ops xfs_allocbt_ops = {
 	.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,
diff --git a/fs/xfs/xfs_alloc_btree.h b/fs/xfs/xfs_alloc_btree.h
index 359fb86ed87..7e89a2b429d 100644
--- a/fs/xfs/xfs_alloc_btree.h
+++ b/fs/xfs/xfs_alloc_btree.h
@@ -93,4 +93,6 @@ extern struct xfs_btree_cur *xfs_allocbt_init_cursor(struct xfs_mount *,
 		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__ */
diff --git a/fs/xfs/xfs_attr_leaf.c b/fs/xfs/xfs_attr_leaf.c
index 5cd5b0c1d17..ee24993c7d1 100644
--- a/fs/xfs/xfs_attr_leaf.c
+++ b/fs/xfs/xfs_attr_leaf.c
@@ -104,22 +104,23 @@ xfs_attr_leaf_verify(
 }
 
 static void
-xfs_attr_leaf_write_verify(
+xfs_attr_leaf_read_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_attr_leaf_verify(bp);
 }
 
-void
-xfs_attr_leaf_read_verify(
+static void
+xfs_attr_leaf_write_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(
@@ -130,7 +131,7 @@ 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);
 }
 
 /*========================================================================
@@ -924,7 +925,7 @@ xfs_attr_leaf_to_node(xfs_da_args_t *args)
 					    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);
@@ -978,7 +979,7 @@ xfs_attr_leaf_create(
 					    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;
diff --git a/fs/xfs/xfs_attr_leaf.h b/fs/xfs/xfs_attr_leaf.h
index 3bbf6277e43..77de139a58f 100644
--- a/fs/xfs/xfs_attr_leaf.h
+++ b/fs/xfs/xfs_attr_leaf.h
@@ -264,6 +264,7 @@ int	xfs_attr_leaf_newentsize(int namelen, int valuelen, int blocksize,
 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__ */
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 6a0f3f9f39d..0e92d12765d 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2663,7 +2663,7 @@ xfs_bmap_btree_to_extents(
 		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);
@@ -3124,7 +3124,7 @@ xfs_bmap_extents_to_btree(
 	/*
 	 * 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;
@@ -3271,7 +3271,7 @@ xfs_bmap_local_to_extents(
 		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);
@@ -4082,7 +4082,7 @@ xfs_bmap_read_extents(
 	 */
 	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);
@@ -4129,7 +4129,7 @@ xfs_bmap_read_extents(
 		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.
 		 */
@@ -4162,7 +4162,7 @@ xfs_bmap_read_extents(
 		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);
@@ -5880,7 +5880,7 @@ xfs_bmap_check_leaf_extents(
 			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;
 		}
@@ -5966,7 +5966,7 @@ xfs_bmap_check_leaf_extents(
 			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;
 		}
@@ -6061,7 +6061,7 @@ xfs_bmap_count_tree(
 	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;
@@ -6073,7 +6073,7 @@ xfs_bmap_count_tree(
 		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;
@@ -6105,7 +6105,7 @@ xfs_bmap_count_tree(
 			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;
diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index 79758e1e4f7..061b45cbe61 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -749,23 +749,26 @@ xfs_bmbt_verify(
 	}
 }
 
-void
-xfs_bmbt_write_verify(
+static void
+xfs_bmbt_read_verify(
 	struct xfs_buf	*bp)
 {
 	xfs_bmbt_verify(bp);
 }
 
-void
-xfs_bmbt_read_verify(
+static void
+xfs_bmbt_write_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
 xfs_bmbt_keys_inorder(
@@ -805,8 +808,7 @@ static const struct xfs_btree_ops xfs_bmbt_ops = {
 	.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,
diff --git a/fs/xfs/xfs_bmap_btree.h b/fs/xfs/xfs_bmap_btree.h
index 938c8598654..88469ca0869 100644
--- a/fs/xfs/xfs_bmap_btree.h
+++ b/fs/xfs/xfs_bmap_btree.h
@@ -232,11 +232,10 @@ extern void xfs_bmbt_to_bmdr(struct xfs_mount *, struct xfs_btree_block *, int,
 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__ */
diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
index 1e2d89eed2a..db010408d70 100644
--- a/fs/xfs/xfs_btree.c
+++ b/fs/xfs/xfs_btree.c
@@ -271,7 +271,7 @@ xfs_btree_dup_cursor(
 			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;
@@ -621,7 +621,7 @@ xfs_btree_read_bufl(
 	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 */
@@ -630,7 +630,7 @@ xfs_btree_read_bufl(
 	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));
@@ -650,13 +650,13 @@ xfs_btree_reada_bufl(
 	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);
 }
 
 /*
@@ -670,14 +670,14 @@ xfs_btree_reada_bufs(
 	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
@@ -692,13 +692,13 @@ xfs_btree_readahead_lblock(
 
 	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++;
 	}
 
@@ -718,13 +718,13 @@ xfs_btree_readahead_sblock(
 
 	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++;
 	}
 
@@ -996,7 +996,7 @@ xfs_btree_get_buf_block(
 	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;
 }
@@ -1024,7 +1024,7 @@ xfs_btree_read_buf_block(
 	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;
 
diff --git a/fs/xfs/xfs_btree.h b/fs/xfs/xfs_btree.h
index 458ab355089..f932897194e 100644
--- a/fs/xfs/xfs_btree.h
+++ b/fs/xfs/xfs_btree.h
@@ -188,8 +188,7 @@ struct xfs_btree_ops {
 	__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 */
@@ -359,7 +358,7 @@ xfs_btree_read_bufl(
 	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.
@@ -370,7 +369,7 @@ xfs_btree_reada_bufl(
 	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.
@@ -382,7 +381,7 @@ xfs_btree_reada_bufs(
 	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
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index bd1a948ee39..26673a0b20e 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -571,7 +571,7 @@ found:
 		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_);
@@ -657,7 +657,7 @@ xfs_buf_read_map(
 	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;
 
@@ -669,7 +669,7 @@ xfs_buf_read_map(
 
 		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) {
 			/*
@@ -696,13 +696,13 @@ 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)
 {
 	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);
 }
 
 /*
@@ -715,7 +715,7 @@ xfs_buf_read_uncached(
 	xfs_daddr_t		daddr,
 	size_t			numblks,
 	int			flags,
-	xfs_buf_iodone_t	verify)
+	const struct xfs_buf_ops *ops)
 {
 	struct xfs_buf		*bp;
 
@@ -728,7 +728,7 @@ xfs_buf_read_uncached(
 	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);
@@ -1001,27 +1001,37 @@ STATIC void
 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);
@@ -1029,6 +1039,7 @@ xfs_buf_ioend(
 			xfs_buf_iodone_work(&bp->b_iodone_work);
 		}
 	} else {
+		bp->b_flags &= ~(XBF_READ | XBF_WRITE | XBF_READ_AHEAD);
 		complete(&bp->b_iowait);
 	}
 }
@@ -1316,6 +1327,20 @@ _xfs_buf_ioapply(
 			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 {
@@ -1326,20 +1351,6 @@ _xfs_buf_ioapply(
 	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
 	 * into the buffer and the desired IO size before we start -
 	 * _xfs_buf_ioapply_vec() will modify them appropriately for each
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 51bc16a1cd9..23f5642480b 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -111,6 +111,11 @@ struct xfs_buf_map {
 #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
@@ -154,9 +159,7 @@ typedef struct xfs_buf {
 	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;
@@ -199,10 +202,11 @@ struct xfs_buf *xfs_buf_get_map(struct xfs_buftarg *target,
 			       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(
@@ -221,10 +225,10 @@ xfs_buf_read(
 	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
@@ -232,10 +236,10 @@ xfs_bu