[PATCH 0/3] btrfs-progs: check: add detection for missing root orphan items

[Qu Wenruo <wqu@suse.com>]

There is an internal bug report that some half-dropped subvolume makes
balance to fail.

It turns out that, the involved subvolume doesn't have an orphan item,
this means the half-dropped subvolume is never going to be cleaned up.

Then at balance time, a reloc tree is created for that half-dropped
subvolume, and since balance doesn't expect to get a half-dropped
subvolume, it doesn't check the drop_process_key and increased ref on
already dropped nodes.

The problem for progs is that, neither original mode nor lowmem detects
this kind of problem.

Original mode has a bad logic which prevents us from calling the proper
orphan item check.
Lowmem mode doesn't even take orphan item into consideration.

This series will add the detection part for btrfs-check, for both
original and lowmem mode, with a hand crafted image for test.

Qu Wenruo (3):
  btrfs-progs: check/original: detect missing orphan items correctly
  btrfs-progs: check/lowmem: detect missing orphan items correctly
  btrfs-progs: fsck-tests: a new test case for missing root orphan item

 check/main.c                                    |   3 +--
 check/mode-lowmem.c                             |  11 +++++++++++
 .../066-missing-root-orphan-item/default.img.xz | Bin 0 -> 13468 bytes
 .../066-missing-root-orphan-item/test.sh        |  14 ++++++++++++++
 4 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 tests/fsck-tests/066-missing-root-orphan-item/default.img.xz
 create mode 100755 tests/fsck-tests/066-missing-root-orphan-item/test.sh

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2.50.0