syzbot

ocfs2: Finishing quota recovery on device (7,2) for slot 0
======================================================
WARNING: possible circular locking dependency detected
6.1.127-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:1/11 is trying to acquire lock:
ffff88806292c0e0 (&type->s_umount_key#50){++++}-{3:3}, at: ocfs2_finish_quota_recovery+0x158/0x2300 fs/ocfs2/quota_local.c:600

but task is already holding lock:
ffffc90000107d20 ((work_completion)(&journal->j_recovery_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 ((work_completion)(&journal->j_recovery_work)){+.+.}-{0:0}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       process_one_work+0x7dc/0x11d0 kernel/workqueue.c:2268
       worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
       kthread+0x28d/0x320 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #1 ((wq_completion)ocfs2_wq#2){+.+.}-{0:0}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __flush_workqueue+0x170/0x1610 kernel/workqueue.c:2812
       ocfs2_shutdown_local_alloc+0x105/0xa90 fs/ocfs2/localalloc.c:379
       ocfs2_dismount_volume+0x1fb/0x960 fs/ocfs2/super.c:1879
       generic_shutdown_super+0x130/0x340 fs/super.c:501
       kill_block_super+0x7a/0xe0 fs/super.c:1470
       deactivate_locked_super+0xa0/0x110 fs/super.c:332
       cleanup_mnt+0x490/0x520 fs/namespace.c:1186
       task_work_run+0x246/0x300 kernel/task_work.c:203
       resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
       exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
       __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
       syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
       do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&type->s_umount_key#50){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       ocfs2_finish_quota_recovery+0x158/0x2300 fs/ocfs2/quota_local.c:600
       ocfs2_complete_recovery+0x18e2/0x2840 fs/ocfs2/journal.c:1324
       process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
       worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
       kthread+0x28d/0x320 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

other info that might help us debug this:

Chain exists of:
  &type->s_umount_key#50 --> (wq_completion)ocfs2_wq#2 --> (work_completion)(&journal->j_recovery_work)

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock((work_completion)(&journal->j_recovery_work));
                               lock((wq_completion)ocfs2_wq#2);
                               lock((work_completion)(&journal->j_recovery_work));
  lock(&type->s_umount_key#50);

 *** DEADLOCK ***

2 locks held by kworker/u4:1/11:
 #0: ffff88807b3bf138 ((wq_completion)ocfs2_wq#2){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000107d20 ((work_completion)(&journal->j_recovery_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267

stack backtrace:
CPU: 0 PID: 11 Comm: kworker/u4:1 Not tainted 6.1.127-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: ocfs2_wq ocfs2_complete_recovery
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
 ocfs2_finish_quota_recovery+0x158/0x2300 fs/ocfs2/quota_local.c:600
 ocfs2_complete_recovery+0x18e2/0x2840 fs/ocfs2/journal.c:1324
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>