[PATCH 24/24] xfs: remove xfs_inobp_check()

[Dave Chinner <david@fromorbit.com>]

From: Dave Chinner <dchinner@redhat.com>

This debug code is called on every xfs_iflush() call, which then
checks every inode in the buffer for non-zero unlinked list field.
Hence it checks every inode in the cluster buffer every time a
single inode on that cluster it flushed. This is resulting in:

-   38.91%     5.33%  [kernel]  [k] xfs_iflush                                                                                                              ▒
   - 17.70% xfs_iflush                                                                                                                                      ▒
      - 9.93% xfs_inobp_check                                                                                                                                   ▒
           4.36% xfs_buf_offset                                                                                                                                 ▒

10% of the CPU time spent flushing inodes is repeatedly checking
unlinked fields in the buffer. We don't need to do this.

The other place we call xfs_inobp_check() is
xfs_iunlink_update_dinode(), and this is after we've done this
assert for the agino we are about to write into that inode:

	ASSERT(xfs_verify_agino_or_null(mp, agno, next_agino));

which means we've already checked that the agino we are about to
write is not 0 on debug kernels. The inode buffer verifiers do
everything else we need, so let's just remove this debug code.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
 fs/xfs/libxfs/xfs_inode_buf.c | 24 ------------------------
 fs/xfs/libxfs/xfs_inode_buf.h |  6 ------
 fs/xfs/xfs_inode.c            |  2 --
 3 files changed, 32 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index 1af97235785c8..6b6f67595bf4e 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -20,30 +20,6 @@
 
 #include <linux/iversion.h>
 
-/*
- * Check that none of the inode's in the buffer have a next
- * unlinked field of 0.
- */
-#if defined(DEBUG)
-void
-xfs_inobp_check(
-	xfs_mount_t	*mp,
-	xfs_buf_t	*bp)
-{
-	int		i;
-	xfs_dinode_t	*dip;
-
-	for (i = 0; i < M_IGEO(mp)->inodes_per_cluster; i++) {
-		dip = xfs_buf_offset(bp, i * mp->m_sb.sb_inodesize);
-		if (!dip->di_next_unlinked)  {
-			xfs_alert(mp,
-	"Detected bogus zero next_unlinked field in inode %d buffer 0x%llx.",
-				i, (long long)bp->b_bn);
-		}
-	}
-}
-#endif
-
 /*
  * If we are doing readahead on an inode buffer, we might be in log recovery
  * reading an inode allocation buffer that hasn't yet been replayed, and hence
diff --git a/fs/xfs/libxfs/xfs_inode_buf.h b/fs/xfs/libxfs/xfs_inode_buf.h
index 865ac493c72a2..6b08b9d060c2e 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.h
+++ b/fs/xfs/libxfs/xfs_inode_buf.h
@@ -52,12 +52,6 @@ int	xfs_inode_from_disk(struct xfs_inode *ip, struct xfs_dinode *from);
 void	xfs_log_dinode_to_disk(struct xfs_log_dinode *from,
 			       struct xfs_dinode *to);
 
-#if defined(DEBUG)
-void	xfs_inobp_check(struct xfs_mount *, struct xfs_buf *);
-#else
-#define	xfs_inobp_check(mp, bp)
-#endif /* DEBUG */
-
 xfs_failaddr_t xfs_dinode_verify(struct xfs_mount *mp, xfs_ino_t ino,
 			   struct xfs_dinode *dip);
 xfs_failaddr_t xfs_inode_validate_extsize(struct xfs_mount *mp,
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 7db0f97e537e3..98a494e42aa6a 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -2146,7 +2146,6 @@ xfs_iunlink_update_dinode(
 	xfs_dinode_calc_crc(mp, dip);
 	xfs_trans_inode_buf(tp, ibp);
 	xfs_trans_log_buf(tp, ibp, offset, offset + sizeof(xfs_agino_t) - 1);
-	xfs_inobp_check(mp, ibp);
 }
 
 /* Set an in-core inode's unlinked pointer and return the old value. */
@@ -3538,7 +3537,6 @@ xfs_iflush(
 	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
 	if (XFS_IFORK_Q(ip))
 		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
-	xfs_inobp_check(mp, bp);
 
 	/*
 	 * We've recorded everything logged in the inode, so we'd like to clear
-- 
2.26.2.761.g0e0b3e54be