xfs: make buffer read verication an IO completion function

Add a verifier function callback capability to the buffer read
interfaces.  This will be used by the callers to supply a function
that verifies the contents of the buffer when it is read from disk.
This patch does not provide callback functions, but simply modifies
the interfaces to allow them to be called.

The reason for adding this to the read interfaces is that it is very
difficult to tell fom the outside is a buffer was just read from
disk or whether we just pulled it out of cache. Supplying a callbck
allows the buffer cache to use it's internal knowledge of the buffer
to execute it only when the buffer is read from disk.

It is intended that the verifier functions will mark the buffer with
an EFSCORRUPTED error when verification fails. This allows the
reading context to distinguish a verification error from an IO
error, and potentially take further actions on the buffer (e.g.
attempt repair) based on the error reported.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phil White <pwhite@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

19 files changed, 75 insertions, 61 deletions

diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 335206a9c698..21c3db08fd01 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -447,7 +447,7 @@ 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_FSS_TO_BB(mp, 1), 0, &bp, NULL);
 	if (error)
 		return error;
 	ASSERT(!xfs_buf_geterror(bp));
@@ -2110,7 +2110,7 @@ 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_FSS_TO_BB(mp, 1), flags, bpp, NULL);
 	if (error)
 		return error;
 	if (!*bpp)
diff --git a/fs/xfs/xfs_attr.c b/fs/xfs/xfs_attr.c
index 55bbe98e8f82..474c57a43cce 100644
--- a/fs/xfs/xfs_attr.c
+++ b/fs/xfs/xfs_attr.c
@@ -1994,7 +1994,7 @@ xfs_attr_rmtval_get(xfs_da_args_t *args)
 			dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
 			blkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
 			error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
-						   dblkno, blkcnt, 0, &bp);
+						   dblkno, blkcnt, 0, &bp, NULL);
 			if (error)
 				return(error);
 
diff --git a/fs/xfs/xfs_btree.c b/fs/xfs/xfs_btree.c
index 121ea99e615a..7e791160092d 100644
--- a/fs/xfs/xfs_btree.c
+++ b/fs/xfs/xfs_btree.c
@@ -266,9 +266,12 @@ xfs_btree_dup_cursor(
 	for (i = 0; i < new->bc_nlevels; i++) {
 		new->bc_ptrs[i] = cur->bc_ptrs[i];
 		new->bc_ra[i] = cur->bc_ra[i];
-		if ((bp = cur->bc_bufs[i])) {
-			if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
-				XFS_BUF_ADDR(bp), mp->m_bsize, 0, &bp))) {
+		bp = cur->bc_bufs[i];
+		if (bp) {
+			error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
+						   XFS_BUF_ADDR(bp), mp->m_bsize,
+						   0, &bp, NULL);
+			if (error) {
 				xfs_btree_del_cursor(new, error);
 				*ncur = NULL;
 				return error;
@@ -624,10 +627,10 @@ xfs_btree_read_bufl(
 
 	ASSERT(fsbno != NULLFSBLOCK);
 	d = XFS_FSB_TO_DADDR(mp, fsbno);
-	if ((error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
-			mp->m_bsize, lock, &bp))) {
+	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, d,
+				   mp->m_bsize, lock, &bp, NULL);
+	if (error)
 		return error;
-	}
 	ASSERT(!xfs_buf_geterror(bp));
 	if (bp)
 		xfs_buf_set_ref(bp, refval);
@@ -650,7 +653,7 @@ xfs_btree_reada_bufl(
 
 	ASSERT(fsbno != NULLFSBLOCK);
 	d = XFS_FSB_TO_DADDR(mp, fsbno);
-	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count);
+	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, NULL);
 }
 
 /*
@@ -670,7 +673,7 @@ xfs_btree_reada_bufs(
 	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);
+	xfs_buf_readahead(mp->m_ddev_targp, d, mp->m_bsize * count, NULL);
 }
 
 STATIC int
@@ -1013,7 +1016,7 @@ 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);
+				   mp->m_bsize, flags, bpp, NULL);
 	if (error)
 		return error;
 
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 4b0b8dd1b7b0..0298dd684798 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -654,7 +654,8 @@ xfs_buf_read_map(
 	struct xfs_buftarg	*target,
 	struct xfs_buf_map	*map,
 	int			nmaps,
-	xfs_buf_flags_t		flags)
+	xfs_buf_flags_t		flags,
+	xfs_buf_iodone_t	verify)
 {
 	struct xfs_buf		*bp;
 
@@ -666,6 +667,7 @@ xfs_buf_read_map(
 
 		if (!XFS_BUF_ISDONE(bp)) {
 			XFS_STATS_INC(xb_get_read);
+			bp->b_iodone = verify;
 			_xfs_buf_read(bp, flags);
 		} else if (flags & XBF_ASYNC) {
 			/*
@@ -691,13 +693,14 @@ void
 xfs_buf_readahead_map(
 	struct xfs_buftarg	*target,
 	struct xfs_buf_map	*map,
-	int			nmaps)
+	int			nmaps,
+	xfs_buf_iodone_t	verify)
 {
 	if (bdi_read_congested(target->bt_bdi))
 		return;
 
 	xfs_buf_read_map(target, map, nmaps,
-		     XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD);
+		     XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD, verify);
 }
 
 /*
@@ -709,7 +712,8 @@ xfs_buf_read_uncached(
 	struct xfs_buftarg	*target,
 	xfs_daddr_t		daddr,
 	size_t			numblks,
-	int			flags)
+	int			flags,
+	xfs_buf_iodone_t	verify)
 {
 	xfs_buf_t		*bp;
 	int			error;
@@ -723,6 +727,7 @@ xfs_buf_read_uncached(
 	bp->b_bn = daddr;
 	bp->b_maps[0].bm_bn = daddr;
 	bp->b_flags |= XBF_READ;
+	bp->b_iodone = verify;
 
 	xfsbdstrat(target->bt_mount, bp);
 	error = xfs_buf_iowait(bp);
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 7c0b6a0a1557..677b1dc822f4 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -100,6 +100,7 @@ typedef struct xfs_buftarg {
 struct xfs_buf;
 typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
 
+
 #define XB_PAGES	2
 
 struct xfs_buf_map {
@@ -159,7 +160,6 @@ typedef struct xfs_buf {
 #endif
 } xfs_buf_t;
 
-
 /* Finding and Reading Buffers */
 struct xfs_buf *_xfs_buf_find(struct xfs_buftarg *target,
 			      struct xfs_buf_map *map, int nmaps,
@@ -196,9 +196,10 @@ 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_flags_t flags, xfs_buf_iodone_t verify);
 void xfs_buf_readahead_map(struct xfs_buftarg *target,
-			       struct xfs_buf_map *map, int nmaps);
+			       struct xfs_buf_map *map, int nmaps,
+			       xfs_buf_iodone_t verify);
 
 static inline struct xfs_buf *
 xfs_buf_get(
@@ -216,20 +217,22 @@ xfs_buf_read(
 	struct xfs_buftarg	*target,
 	xfs_daddr_t		blkno,
 	size_t			numblks,
-	xfs_buf_flags_t		flags)
+	xfs_buf_flags_t		flags,
+	xfs_buf_iodone_t	verify)
 {
 	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
-	return xfs_buf_read_map(target, &map, 1, flags);
+	return xfs_buf_read_map(target, &map, 1, flags, verify);
 }
 
 static inline void
 xfs_buf_readahead(
 	struct xfs_buftarg	*target,
 	xfs_daddr_t		blkno,
-	size_t			numblks)
+	size_t			numblks,
+	xfs_buf_iodone_t	verify)
 {
 	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
-	return xfs_buf_readahead_map(target, &map, 1);
+	return xfs_buf_readahead_map(target, &map, 1, verify);
 }
 
 struct xfs_buf *xfs_buf_get_empty(struct xfs_buftarg *target, size_t numblks);
@@ -239,7 +242,8 @@ int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length);
 struct xfs_buf *xfs_buf_get_uncached(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_daddr_t daddr, size_t numblks, int flags,
+				xfs_buf_iodone_t verify);
 void xfs_buf_hold(struct xfs_buf *bp);
 
 /* Releasing Buffers */
diff --git a/fs/xfs/xfs_da_btree.c b/fs/xfs/xfs_da_btree.c
index c62e7e6ff50e..4af8bad7068c 100644
--- a/fs/xfs/xfs_da_btree.c
+++ b/fs/xfs/xfs_da_btree.c
@@ -2161,7 +2161,7 @@ xfs_da_read_buf(
 
 	error = xfs_trans_read_buf_map(dp->i_mount, trans,
 					dp->i_mount->m_ddev_targp,
-					mapp, nmap, 0, &bp);
+					mapp, nmap, 0, &bp, NULL);
 	if (error)
 		goto out_free;
 
@@ -2237,7 +2237,7 @@ xfs_da_reada_buf(
 	}
 
 	mappedbno = mapp[0].bm_bn;
-	xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap);
+	xfs_buf_readahead_map(dp->i_mount->m_ddev_targp, mapp, nmap, NULL);
 
 out_free:
 	if (mapp != &map)
diff --git a/fs/xfs/xfs_dir2_leaf.c b/fs/xfs/xfs_dir2_leaf.c
index 0b296253bd01..bac86984e403 100644
--- a/fs/xfs/xfs_dir2_leaf.c
+++ b/fs/xfs/xfs_dir2_leaf.c
@@ -926,7 +926,7 @@ xfs_dir2_leaf_readbuf(
 				XFS_FSB_TO_DADDR(mp,
 					map[mip->ra_index].br_startblock +
 							mip->ra_offset),
-				(int)BTOBB(mp->m_dirblksize));
+				(int)BTOBB(mp->m_dirblksize), NULL);
 			mip->ra_current = i;
 		}
 
diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index bf27fcca4843..e95f800333d4 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -439,7 +439,7 @@ xfs_qm_dqtobp(
 		error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 					   dqp->q_blkno,
 					   mp->m_quotainfo->qi_dqchunklen,
-					   0, &bp);
+					   0, &bp, NULL);
 		if (error || !bp)
 			return XFS_ERROR(error);
 	}
@@ -920,7 +920,7 @@ xfs_qm_dqflush(
 	 * Get the buffer containing the on-disk dquot
 	 */
 	error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
-				   mp->m_quotainfo->qi_dqchunklen, 0, &bp);
+				   mp->m_quotainfo->qi_dqchunklen, 0, &bp, NULL);
 	if (error)
 		goto out_unlock;
 
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index bd9cb7f0b073..5440768ec41c 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -168,7 +168,7 @@ xfs_growfs_data_private(
 	dpct = pct - mp->m_sb.sb_imax_pct;
 	bp = xfs_buf_read_uncached(mp->m_ddev_targp,
 				XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
-				XFS_FSS_TO_BB(mp, 1), 0);
+				XFS_FSS_TO_BB(mp, 1), 0, NULL);
 	if (!bp)
 		return EIO;
 	xfs_buf_relse(bp);
@@ -439,7 +439,7 @@ xfs_growfs_data_private(
 		if (agno < oagcount) {
 			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_FSS_TO_BB(mp, 1), 0, &bp, NULL);
 		} else {
 			bp = xfs_trans_get_buf(NULL, mp->m_ddev_targp,
 				  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index 37753e1c8537..12e3dead439d 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -1490,7 +1490,7 @@ xfs_read_agi(
 
 	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_FSS_TO_BB(mp, 1), 0, bpp, NULL);
 	if (error)
 		return error;
 
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 7449cb943efd..8d6963010489 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -408,7 +408,7 @@ xfs_imap_to_bp(
 
 	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);
+				   (int)imap->im_len, buf_flags, &bp, NULL);
 	if (error) {
 		if (error != EAGAIN) {
 			xfs_warn(mp,
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 46b6986e39b0..1d6d2ee08495 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1129,8 +1129,7 @@ xlog_iodone(xfs_buf_t *bp)
 	 * with it being freed after writing the unmount record to the
 	 * log.
 	 */
-
-}	/* xlog_iodone */
+}
 
 /*
  * Return size of each in-core log record buffer.
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 3e06333d4bd1..eb1e29ff0c7c 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -2144,7 +2144,7 @@ xlog_recover_buffer_pass2(
 		buf_flags |= XBF_UNMAPPED;
 
 	bp = xfs_buf_read(mp->m_ddev_targp, buf_f->blf_blkno, buf_f->blf_len,
-			  buf_flags);
+			  buf_flags, NULL);
 	if (!bp)
 		return XFS_ERROR(ENOMEM);
 	error = bp->b_error;
@@ -2237,7 +2237,8 @@ xlog_recover_inode_pass2(
 	}
 	trace_xfs_log_recover_inode_recover(log, in_f);
 
-	bp = xfs_buf_read(mp->m_ddev_targp, in_f->ilf_blkno, in_f->ilf_len, 0);
+	bp = xfs_buf_read(mp->m_ddev_targp, in_f->ilf_blkno, in_f->ilf_len, 0,
+			  NULL);
 	if (!bp) {
 		error = ENOMEM;
 		goto error;
@@ -2548,7 +2549,8 @@ xlog_recover_dquot_pass2(
 	ASSERT(dq_f->qlf_len == 1);
 
 	error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dq_f->qlf_blkno,
-				   XFS_FSB_TO_BB(mp, dq_f->qlf_len), 0, &bp);
+				   XFS_FSB_TO_BB(mp, dq_f->qlf_len), 0, &bp,
+				   NULL);
 	if (error)
 		return error;
 
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 41ae7e1590f5..d5402b0eb6a3 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -652,7 +652,7 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 
 reread:
 	bp = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR,
-					BTOBB(sector_size), 0);
+					BTOBB(sector_size), 0, NULL);
 	if (!bp) {
 		if (loud)
 			xfs_warn(mp, "SB buffer read failed");
@@ -1002,7 +1002,7 @@ xfs_check_sizes(xfs_mount_t *mp)
 	}
 	bp = xfs_buf_read_uncached(mp->m_ddev_targp,
 					d - XFS_FSS_TO_BB(mp, 1),
-					XFS_FSS_TO_BB(mp, 1), 0);
+					XFS_FSS_TO_BB(mp, 1), 0, NULL);
 	if (!bp) {
 		xfs_warn(mp, "last sector read failed");
 		return EIO;
@@ -1017,7 +1017,7 @@ xfs_check_sizes(xfs_mount_t *mp)
 		}
 		bp = xfs_buf_read_uncached(mp->m_logdev_targp,
 					d - XFS_FSB_TO_BB(mp, 1),
-					XFS_FSB_TO_BB(mp, 1), 0);
+					XFS_FSB_TO_BB(mp, 1), 0, NULL);
 		if (!bp) {
 			xfs_warn(mp, "log device read failed");
 			return EIO;
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 48c750b0e830..688f608b3668 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -892,7 +892,7 @@ xfs_qm_dqiter_bufs(
 	while (blkcnt--) {
 		error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
 			      XFS_FSB_TO_DADDR(mp, bno),
-			      mp->m_quotainfo->qi_dqchunklen, 0, &bp);
+			      mp->m_quotainfo->qi_dqchunklen, 0, &bp, NULL);
 		if (error)
 			break;
 
@@ -979,7 +979,8 @@ xfs_qm_dqiterate(
 				while (rablkcnt--) {
 					xfs_buf_readahead(mp->m_ddev_targp,
 					       XFS_FSB_TO_DADDR(mp, rablkno),
-					       mp->m_quotainfo->qi_dqchunklen);
+					       mp->m_quotainfo->qi_dqchunklen,
+					       NULL);
 					rablkno++;
 				}
 			}
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index a69e0b4750a9..b271ed939d7b 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -870,7 +870,7 @@ xfs_rtbuf_get(
 	ASSERT(map.br_startblock != NULLFSBLOCK);
 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
 				   XFS_FSB_TO_DADDR(mp, map.br_startblock),
-				   mp->m_bsize, 0, &bp);
+				   mp->m_bsize, 0, &bp, NULL);
 	if (error)
 		return error;
 	ASSERT(!xfs_buf_geterror(bp));
@@ -1873,7 +1873,7 @@ xfs_growfs_rt(
 	 */
 	bp = xfs_buf_read_uncached(mp->m_rtdev_targp,
 				XFS_FSB_TO_BB(mp, nrblocks - 1),
-				XFS_FSB_TO_BB(mp, 1), 0);
+				XFS_FSB_TO_BB(mp, 1), 0, NULL);
 	if (!bp)
 		return EIO;
 	xfs_buf_relse(bp);
@@ -2220,7 +2220,7 @@ xfs_rtmount_init(
 	}
 	bp = xfs_buf_read_uncached(mp->m_rtdev_targp,
 					d - XFS_FSB_TO_BB(mp, 1),
-					XFS_FSB_TO_BB(mp, 1), 0);
+					XFS_FSB_TO_BB(mp, 1), 0, NULL);
 	if (!bp) {
 		xfs_warn(mp, "realtime device size check failed");
 		return EIO;
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index db056544cbb5..f02d40296506 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -464,10 +464,7 @@ xfs_trans_get_buf(
 	int			numblks,
 	uint			flags)
 {
-	struct xfs_buf_map	map = {
-		.bm_bn = blkno,
-		.bm_len = numblks,
-	};
+	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
 	return xfs_trans_get_buf_map(tp, target, &map, 1, flags);
 }
 
@@ -476,7 +473,8 @@ int		xfs_trans_read_buf_map(struct xfs_mount *mp,
 				       struct xfs_buftarg *target,
 				       struct xfs_buf_map *map, int nmaps,
 				       xfs_buf_flags_t flags,
-				       struct xfs_buf **bpp);
+				       struct xfs_buf **bpp,
+				       xfs_buf_iodone_t verify);
 
 static inline int
 xfs_trans_read_buf(
@@ -486,13 +484,12 @@ xfs_trans_read_buf(
 	xfs_daddr_t		blkno,
 	int			numblks,
 	xfs_buf_flags_t		flags,
-	struct xfs_buf		**bpp)
+	struct xfs_buf		**bpp,
+	xfs_buf_iodone_t	verify)
 {
-	struct xfs_buf_map	map = {
-		.bm_bn = blkno,
-		.bm_len = numblks,
-	};
-	return xfs_trans_read_buf_map(mp, tp, target, &map, 1, flags, bpp);
+	DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
+	return xfs_trans_read_buf_map(mp, tp, target, &map, 1,
+				      flags, bpp, verify);
 }
 
 struct xfs_buf	*xfs_trans_getsb(xfs_trans_t *, struct xfs_mount *, int);
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 6311b99c267f..977628207b45 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -257,7 +257,8 @@ xfs_trans_read_buf_map(
 	struct xfs_buf_map	*map,
 	int			nmaps,
 	xfs_buf_flags_t		flags,
-	struct xfs_buf		**bpp)
+	struct xfs_buf		**bpp,
+	xfs_buf_iodone_t	verify)
 {
 	xfs_buf_t		*bp;
 	xfs_buf_log_item_t	*bip;
@@ -265,7 +266,7 @@ xfs_trans_read_buf_map(
 
 	*bpp = NULL;
 	if (!tp) {
-		bp = xfs_buf_read_map(target, map, nmaps, flags);
+		bp = xfs_buf_read_map(target, map, nmaps, flags, verify);
 		if (!bp)
 			return (flags & XBF_TRYLOCK) ?
 					EAGAIN : XFS_ERROR(ENOMEM);
@@ -312,7 +313,9 @@ xfs_trans_read_buf_map(
 		if (!(XFS_BUF_ISDONE(bp))) {
 			trace_xfs_trans_read_buf_io(bp, _RET_IP_);
 			ASSERT(!XFS_BUF_ISASYNC(bp));
+			ASSERT(bp->b_iodone == NULL);
 			XFS_BUF_READ(bp);
+			bp->b_iodone = verify;
 			xfsbdstrat(tp->t_mountp, bp);
 			error = xfs_buf_iowait(bp);
 			if (error) {
@@ -349,7 +352,7 @@ xfs_trans_read_buf_map(
 		return 0;
 	}
 
-	bp = xfs_buf_read_map(target, map, nmaps, flags);
+	bp = xfs_buf_read_map(target, map, nmaps, flags, verify);
 	if (bp == NULL) {
 		*bpp = NULL;
 		return (flags & XBF_TRYLOCK) ?
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 81c61fd17890..26880793feca 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -80,7 +80,7 @@ xfs_readlink_bmap(
 		d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
 		byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
 
-		bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0);
+		bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0, NULL);
 		if (!bp)
 			return XFS_ERROR(ENOMEM);
 		error = bp->b_error;