xfs: use the directory name hash function for dir scrubbing

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

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);