linux/fs/quota
Shashank A P 72b7ceca85 fs: quota: create dedicated workqueue for quota_release_work
There is a kernel panic due to WARN_ONCE when panic_on_warn is set.

This issue occurs when writeback is triggered due to sync call for an
opened file(ie, writeback reason is WB_REASON_SYNC). When f2fs balance
is needed at sync path, flush for quota_release_work is triggered.
By default quota_release_work is queued to "events_unbound" queue which
does not have WQ_MEM_RECLAIM flag. During f2fs balance "writeback"
workqueue tries to flush quota_release_work causing kernel panic due to
MEM_RECLAIM flag mismatch errors.

This patch creates dedicated workqueue with WQ_MEM_RECLAIM flag
for work quota_release_work.

------------[ cut here ]------------
WARNING: CPU: 4 PID: 14867 at kernel/workqueue.c:3721 check_flush_dependency+0x13c/0x148
Call trace:
 check_flush_dependency+0x13c/0x148
 __flush_work+0xd0/0x398
 flush_delayed_work+0x44/0x5c
 dquot_writeback_dquots+0x54/0x318
 f2fs_do_quota_sync+0xb8/0x1a8
 f2fs_write_checkpoint+0x3cc/0x99c
 f2fs_gc+0x190/0x750
 f2fs_balance_fs+0x110/0x168
 f2fs_write_single_data_page+0x474/0x7dc
 f2fs_write_data_pages+0x7d0/0xd0c
 do_writepages+0xe0/0x2f4
 __writeback_single_inode+0x44/0x4ac
 writeback_sb_inodes+0x30c/0x538
 wb_writeback+0xf4/0x440
 wb_workfn+0x128/0x5d4
 process_scheduled_works+0x1c4/0x45c
 worker_thread+0x32c/0x3e8
 kthread+0x11c/0x1b0
 ret_from_fork+0x10/0x20
Kernel panic - not syncing: kernel: panic_on_warn set ...

Fixes: ac6f420291 ("quota: flush quota_release_work upon quota writeback")
CC: stable@vger.kernel.org
Signed-off-by: Shashank A P <shashank.ap@samsung.com>
Link: https://patch.msgid.link/20250901092905.2115-1-shashank.ap@samsung.com
Signed-off-by: Jan Kara <jack@suse.cz>
2025-09-03 12:35:00 +02:00
..
Kconfig reiserfs: The last commit 2024-10-21 16:29:38 +02:00
Makefile
compat.h
dquot.c fs: quota: create dedicated workqueue for quota_release_work 2025-09-03 12:35:00 +02:00
kqid.c
netlink.c
quota.c fdget_raw() users: switch to CLASS(fd_raw) 2024-11-03 01:28:06 -05:00
quota_tree.c quota: Detect loops in quota tree 2024-02-12 14:14:49 +01:00
quota_tree.h
quota_v1.c quota: remove unneeded return value of register_quota_format 2024-07-22 18:13:44 +02:00
quota_v2.c quota: remove unneeded return value of register_quota_format 2024-07-22 18:13:44 +02:00
quotaio_v1.h
quotaio_v2.h