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>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index f02d40296506..c6c0601abd7a 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -474,7 +474,7 @@ int		xfs_trans_read_buf_map(struct xfs_mount *mp,
 				       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(
@@ -485,11 +485,11 @@ 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);