[PATCH 3/4] xfs: use the directory name hash function for dir scrubbing

Darrick J. Wong
2023-04-06T00:04:06Z

The directory code has a directory-specific hash computation function
that includes a modified hash function for case-insensitive lookups.
Hence we must use that function (and not the raw da_hashname) when
checking the dabtree structure.

Found by accidentally breaking xfs/188 to create an abnormally huge
case-insensitive directory and watching scrub break.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/scrub/dir.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index d1b0f23c2c59..aeb815a483ff 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -201,6 +201,7 @@ xchk_dir_rec(
struct xchk_da_btree *ds,
int level)
{
+ struct xfs_name dname = { };
struct xfs_da_state_blk *blk = &ds->state->path.blk[level];
struct xfs_mount *mp = ds->state->mp;
struct xfs_inode *dp = ds->dargs.dp;
@@ -297,7 +298,11 @@ xchk_dir_rec(
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
goto out_relse;
}
- calc_hash = xfs_da_hashname(dent->name, dent->namelen);
+
+ /* Does the directory hash match? */
+ dname.name = dent->name;
+ dname.len = dent->namelen;
+ calc_hash = xfs_dir2_hashname(mp, &dname);
if (calc_hash != hash)
xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);