[0/4] xfs: fix various scrub problems

Message

Darrick J. Wong Nov. 9, 2020, 6:17 p.m. UTC

Hi all,

While continuing my assessment of the online fsck code, I observed
various other minor problems in the online scrub code.  The most serious
of the bugs involves the extent reference count checker, which
incorrectly counts the number of rmaps it loads into the shared-extent
record stack, and results in scrub being unable to detect off-by-one
errors in the reference count.

The three patches after that tighten the checking around the mininum
number of records in a btree block; flags for rmap records; and
validating that a null entry in the leaf bestfree block actually
correspond to a hole in the directory data segment.

If you're going to start using this mess, you probably ought to just
pull from my git trees, which are linked below.

This is an extraordinary way to destroy everything.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=scrub-fixes-5.10
---
 fs/xfs/scrub/bmap.c     |    8 ++++----
 fs/xfs/scrub/btree.c    |   45 +++++++++++++++++++++++++++------------------
 fs/xfs/scrub/dir.c      |   27 ++++++++++++++++++++-------
 fs/xfs/scrub/refcount.c |    8 +++-----
 4 files changed, 54 insertions(+), 34 deletions(-)