From 6b48e5b8a20f653b7d64ccf99a498f2523bff752 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 8 Nov 2020 16:32:42 -0800 Subject: [PATCH] xfs: directory scrub should check the null bestfree entries too 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. Fixes: df481968f33b ("xfs: scrub directory freespace") Signed-off-by: Darrick J. Wong Reviewed-by: Chandan Babu R Reviewed-by: Christoph Hellwig --- fs/xfs/scrub/dir.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 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); - if (best == NULLDATAOFF) - continue; error = xfs_dir3_data_read(sc->tp, sc->ip, - i * args->geo->fsbcount, 0, &dbp); + 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; - xchk_directory_check_freesp(sc, lblk, dbp, best); + + if (!dbp) { + if (best != NULLDATAOFF) { + xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, + lblk); + break; + } + continue; + } + + if (best == NULLDATAOFF) + 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;