On Monday 9 November 2020 11:47:58 PM IST Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Teach the directory scrubber to check all the bestfree entries,
> including the null ones. We want to be able to detect the case where
> the entry is null but there actually /is/ a directory data block.
>
> Found by fuzzing lbests[0] = ones in xfs/391.
>
Looks good to me.
Reviewed-by: Chandan Babu R <chandanrlinux@xxxxxxxxx>
> Fixes: df481968f33b ("xfs: scrub directory freespace")
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> fs/xfs/scrub/dir.c | 27 ++++++++++++++++++++-------
> 1 file changed, 20 insertions(+), 7 deletions(-)
>
>
> diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
> index 7c432997edad..b045e95c2ea7 100644
> --- a/fs/xfs/scrub/dir.c
> +++ b/fs/xfs/scrub/dir.c
> @@ -558,14 +558,27 @@ xchk_directory_leaf1_bestfree(
> /* Check all the bestfree entries. */
> for (i = 0; i < bestcount; i++, bestp++) {
> best = be16_to_cpu(*bestp);
> + error = xfs_dir3_data_read(sc->tp, sc->ip,
> + xfs_dir2_db_to_da(args->geo, i),
> + XFS_DABUF_MAP_HOLE_OK,
> + &dbp);
> + if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
> + &error))
> + break;
> +
> + if (!dbp) {
> + if (best != NULLDATAOFF) {
> + xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
> + lblk);
> + break;
> + }
> + continue;
> + }
> +
> if (best == NULLDATAOFF)
> - continue;
> - error = xfs_dir3_data_read(sc->tp, sc->ip,
> - i * args->geo->fsbcount, 0, &dbp);
> - if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
> - &error))
> - break;
> - xchk_directory_check_freesp(sc, lblk, dbp, best);
> + xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
> + else
> + xchk_directory_check_freesp(sc, lblk, dbp, best);
> xfs_trans_brelse(sc->tp, dbp);
> if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
> break;
>
>
--
chandan
