[bug report] xfs: scrub directory freespace

[Dan Carpenter <dan.carpenter@oracle.com>]

Hello Darrick J. Wong,

The patch df481968f33b: "xfs: scrub directory freespace" from Oct 17,
2017, leads to the following static checker warning:

	fs/xfs/scrub/dir.c:446 xfs_scrub_directory_check_freesp()
	info: ignoring unreachable code.

fs/xfs/scrub/dir.c
   431  STATIC void
   432  xfs_scrub_directory_check_freesp(
   433          struct xfs_scrub_context        *sc,
   434          xfs_dablk_t                     lblk,
   435          struct xfs_buf                  *dbp,
   436          unsigned int                    len)
   437  {
   438          struct xfs_dir2_data_free       *bf;
   439          struct xfs_dir2_data_free       *dfp;
   440          int                             offset;
   441  
   442          if (len == 0)
   443                  return;
   444  
   445          bf = sc->ip->d_ops->data_bestfree_p(dbp->b_addr);
   446          for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
                                                                      ^^^^^
This looks like a loop

   447                  offset = be16_to_cpu(dfp->offset);
   448                  if (offset == 0)
   449                          break;
   450                  if (len == be16_to_cpu(dfp->length))
   451                          return;
   452                  /* Didn't find the best length in the bestfree data */
   453                  break;
                        ^^^^^^
but we always either break or return on the first iteration.  What's
going on?

   454          }
   455  
   456          xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
   457  }

regards,
dan carpenter