[PATCH 00/12] btrfs-progs: fix btrfs_path leak, part 2

[Qu Wenruo <wqu@suse.com>]

This is the part 2, focusing on the on-stack btrfs_path.

Unlike heap-allocated btrfs_path, which needs proper btrfs_free_path()
call, or the btrfs_path itself along with the held ebs will leak.

The on-stack one only leaks the held ebs, but still we should fix them.

Just by the amount of code, one should know this is largely generated by
LLM, although I spent more time drafting the plan and review the final
patch.

There are some extra notes other than just converting existing
"btrfs_path" on-stack declaration to BTRFS_PATH_AUTO_RELEASE:

- If a label is only for cleanup, remove the label when possible
  As a lot of call sites can directly return without jumping to the
  cleanup label.

  Also cleanup some "ret = x; return ret;" patterns.

- Keep dedicated btrfs_release_path() if needed
  As our C code is not fully aligning the path lifespan with the scope,
  we still need to manually release path halfway for certain call sites.

  E.g. before calling btrfs_commit_transaction(),
  btrfs_abort_transaction(), btrfs_search_slot(), close_ctree() or
  before lowmem mode modifying the tree.

  Releasing the path before btrfs_commit_transaction() is to follow the
  kernel convension. There are a lot of existing call sites breaking it,
  so here we do not intentionally fix them.

  This will require a dedicated change in the future.

- Reduce the lifespan of btrfs_path when possible
  E.g. the path is only utilized inside a loop or if () branch, declare
  path there.

This applies to patch 01~08, which are all straightforward conversion
with minor cleanups.

After that, the code review process exposed some other bugs in the
touched functions, which are all pretty simple and low severity ones.
Patch 09~12 are to fix those minor bugs.

Qu Wenruo (12):
  btrfs-progs: kernel-shared: use BTRFS_PATH_AUTO_RELEASE() for on-stack
    paths
  btrfs-progs: common, convert, image: use BTRFS_PATH_AUTO_RELEASE() for
    on-stack paths
  btrfs-progs: mkfs: use BTRFS_PATH_AUTO_RELEASE() for on-stack paths
  btrfs-progs: tune: use BTRFS_PATH_AUTO_RELEASE() for on-stack paths
  btrfs-progs: cmds: use BTRFS_PATH_AUTO_RELEASE() for on-stack paths
  btrfs-progs: check: use BTRFS_PATH_AUTO_RELEASE() for repair,
    qgroup-verify and mode-common
  btrfs-progs: check: use BTRFS_PATH_AUTO_RELEASE() for lowmem mode
  btrfs-progs: check: use BTRFS_PATH_AUTO_RELEASE() for original mode
  btrfs-progs: check: fix fixup_extent_flags() retry path
  btrfs-progs: fix missing transaction commit in
    truncate_free_ino_items()
  btrfs-progs: dump-tree: fix exit code and leak on open failure
  btrfs-progs: check: return error if fill_csum_tree_from_fs() fails to
    read a root

 check/main.c                     | 235 +++++++++++--------------------
 check/mode-common.c              | 141 +++++++------------
 check/mode-lowmem.c              | 202 +++++++++-----------------
 check/qgroup-verify.c            |  29 ++--
 check/repair.c                   |   5 +-
 cmds/device.c                    |  11 +-
 cmds/inspect-dump-tree.c         |  11 +-
 cmds/rescue-chunk-recover.c      |  43 ++----
 cmds/rescue-fix-data-checksum.c  |  10 +-
 cmds/rescue.c                    |   7 +-
 cmds/restore.c                   | 126 +++++++----------
 common/clear-cache.c             |  79 ++++-------
 common/root-tree-utils.c         |  10 +-
 convert/main.c                   |   9 +-
 convert/source-ext2.c            |   3 +-
 convert/source-fs.c              |   3 +-
 image/common.c                   |   2 +-
 image/image-create.c             |   2 +-
 image/image-restore.c            |  20 +--
 kernel-shared/extent-tree.c      |  62 +++-----
 kernel-shared/file.c             |   3 +-
 kernel-shared/free-space-cache.c |  24 ++--
 kernel-shared/inode.c            |   8 +-
 kernel-shared/print-tree.c       |   9 +-
 kernel-shared/volumes.c          |  15 +-
 mkfs/main.c                      |  42 ++----
 mkfs/rootdir.c                   |  36 ++---
 tests/btree-test.c               |   2 +-
 tune/change-csum.c               |  50 ++-----
 tune/change-uuid.c               |  38 ++---
 tune/convert-remap-tree.c        |  12 +-
 tune/quota.c                     |  19 ++-
 32 files changed, 447 insertions(+), 821 deletions(-)

--
2.56.0