[PATCH 0/2] btrfs-progs: fix an old bug in lowmem mode

[Qu Wenruo <wqu@suse.com>]

Inspired by Mark's recent enhanced super block dev item check against
chunk tree device item, it turns out there are several existing images
not passing the check.

One of the check is fsck/020/keyed_data_ref_with_reloc_leaf.img, which
may be caused by some older kernels (the bug is already fixed a long
time ago).

The first patch is to fix a lowmem mode check bug, that it doesn't
correctly account the keyed backref with shared backref.

This is exposed by the image from the next patch.

Then the last patch is to update the image with a proper note on how to
re-create it.
And the new image also acts as a regression test for the above lowmem
bug.

Please note this is not the last fsck image which has such problem,
fsck/057 is another one, and will be addressed in a dedicated patch.

Qu Wenruo (2):
  btrfs-progs: check/lowmem: fix a false alert when counting the refs
  btrfs-progs: fsck-tests: fix an image which has incorrect super dev
    item

 check/mode-lowmem.c                           | 145 +++++++++++++++++-
 .../keyed_data_ref_with_reloc_leaf.img        | Bin 16384 -> 19456 bytes
 2 files changed, 139 insertions(+), 6 deletions(-)

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2.49.0