[PATCH V6 00/10] null_blk: fix init/exit races and memleaks

From: Zizhi Wo <[email protected]>

This series fixes several issues in null_blk around lock initialization,
memory leaks, concurrent configfs access, and module init/exit.

See the individual patch descriptions for details.

Changes since v5:
- Add a new patch converting the file-scope mutex users to gaurd(mutex).
- Simplify the last two patches accordingly.
https://lore.kernel.org/all/[email protected]/

Changes since v4:
- Modified patch 5 to fix the check-and-deref race on dev->zones in
  zone_cond_store().
- Simplified the fix in patch 7.
https://lore.kernel.org/all/[email protected]/

Changes since v3:
- Added patch 5 (zones array memleak) and patch 6 (cleanup).
- Added patch 7 (NULL-ptr-deref on shared tag_set queue shrink).
- Patch 9: reworked the fix from v3's patch 6 to take the file-scope
  lock in _store instead of scattering READ_ONCE/WRITE_ONCE.
https://lore.kernel.org/all/[email protected]/

Changes since v2:
- Dropped the lock rename patch; the rename and locking rework will be
  sent as a separate series (per Damien's suggestion).
- Patch 3: fixed the tense in the commit message.
- Patch 4: also update dev->NAME in the "!dev->nullb" path, which was
  previously lost.
https://lore.kernel.org/all/[email protected]/

Changes since v1:
- Added patches 4-6, and modify the lock name in patch 2.
https://lore.kernel.org/all/[email protected]/


Zizhi Wo (10):
  null_blk: use DEFINE_MUTEX for the file-scope mutex
  null_blk: register configfs subsystem after creating default devices
  null_blk: move unregister_blkdev() after destroying dev in null_exit()
  null_blk: free global tag_set on init error path
  null_blk: free zones array on device power-off
  null_blk: clean up null_del_dev() to use cached dev pointer
  null_blk: reject per-device queue resize for shared tag set
  null_blk: convert file-scope mutex users to guard(mutex)
  null_blk: serialize configfs attribute stores with the lock
  null_blk: serialize configfs attribute shows with the lock

 drivers/block/null_blk/main.c | 92 ++++++++++++++++-------------------
 1 file changed, 43 insertions(+), 49 deletions(-)

-- 
2.52.0