xfs: refactor the directory data block bestfree checks
authorDarrick J. Wong <darrick.wong@oracle.com>
Mon, 6 Nov 2017 19:37:46 +0000 (11:37 -0800)
committerDarrick J. Wong <darrick.wong@oracle.com>
Thu, 9 Nov 2017 17:10:45 +0000 (09:10 -0800)
In a directory data block, the zeroth bestfree item must point to the
longest free space.  Therefore, when we check the bestfree block's
records against the data blocks, we only need to compare with bf[0] and
don't need the loop.

The weird loop was most probably the result of an earlier refactoring
gone bad.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
fs/xfs/scrub/dir.c

index d4cd766..c8ca3fd 100644 (file)
@@ -435,25 +435,15 @@ xfs_scrub_directory_check_freesp(
        struct xfs_buf                  *dbp,
        unsigned int                    len)
 {
-       struct xfs_dir2_data_free       *bf;
        struct xfs_dir2_data_free       *dfp;
-       int                             offset;
 
-       if (len == 0)
-               return;
+       dfp = sc->ip->d_ops->data_bestfree_p(dbp->b_addr);
 
-       bf = sc->ip->d_ops->data_bestfree_p(dbp->b_addr);
-       for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
-               offset = be16_to_cpu(dfp->offset);
-               if (offset == 0)
-                       break;
-               if (len == be16_to_cpu(dfp->length))
-                       return;
-               /* Didn't find the best length in the bestfree data */
-               break;
-       }
+       if (len != be16_to_cpu(dfp->length))
+               xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 
-       xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+       if (len > 0 && be16_to_cpu(dfp->offset) == 0)
+               xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 }
 
 /* Check free space info in a directory leaf1 block. */