syzbot

======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc1-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor984/5828 is trying to acquire lock:
ffff888027ba1948 ((wq_completion)ocfs2_wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0xb1/0x170 kernel/workqueue.c:3907

but task is already holding lock:
ffff888032c9e0e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
ffff888032c9e0e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
ffff888032c9e0e0 (&type->s_umount_key#45){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&type->s_umount_key#45){++++}-{4:4}:
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       down_read+0xb3/0xa50 kernel/locking/rwsem.c:1524
       ocfs2_finish_quota_recovery+0x15e/0x2310 fs/ocfs2/quota_local.c:603
       ocfs2_complete_recovery+0x1977/0x2580 fs/ocfs2/journal.c:1357
       process_one_work kernel/workqueue.c:3238 [inline]
       process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
       worker_thread+0x870/0xd50 kernel/workqueue.c:3400
       kthread+0x7b7/0x940 kernel/kthread.c:464
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #1 ((work_completion)(&journal->j_recovery_work)){+.+.}-{0:0}:
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       process_one_work kernel/workqueue.c:3214 [inline]
       process_scheduled_works+0x9e9/0x18e0 kernel/workqueue.c:3319
       worker_thread+0x870/0xd50 kernel/workqueue.c:3400
       kthread+0x7b7/0x940 kernel/kthread.c:464
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 ((wq_completion)ocfs2_wq){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3166 [inline]
       check_prevs_add kernel/locking/lockdep.c:3285 [inline]
       validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
       __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       touch_wq_lockdep_map+0xc7/0x170 kernel/workqueue.c:3907
       __flush_workqueue+0x14c/0x1280 kernel/workqueue.c:3949
       ocfs2_shutdown_local_alloc+0x10b/0xab0 fs/ocfs2/localalloc.c:380
       ocfs2_dismount_volume+0x204/0x910 fs/ocfs2/super.c:1822
       generic_shutdown_super+0x139/0x2d0 fs/super.c:642
       kill_block_super+0x44/0x90 fs/super.c:1710
       deactivate_locked_super+0xc4/0x130 fs/super.c:473
       cleanup_mnt+0x422/0x4c0 fs/namespace.c:1435
       task_work_run+0x251/0x310 kernel/task_work.c:227
       exit_task_work include/linux/task_work.h:40 [inline]
       do_exit+0xa11/0x27f0 kernel/exit.c:953
       do_group_exit+0x207/0x2c0 kernel/exit.c:1102
       __do_sys_exit_group kernel/exit.c:1113 [inline]
       __se_sys_exit_group kernel/exit.c:1111 [inline]
       __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
       x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  (wq_completion)ocfs2_wq --> (work_completion)(&journal->j_recovery_work) --> &type->s_umount_key#45

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&type->s_umount_key#45);
                               lock((work_completion)(&journal->j_recovery_work));
                               lock(&type->s_umount_key#45);
  lock((wq_completion)ocfs2_wq);

 *** DEADLOCK ***

1 lock held by syz-executor984/5828:
 #0: ffff888032c9e0e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888032c9e0e0 (&type->s_umount_key#45){++++}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888032c9e0e0 (&type->s_umount_key#45){++++}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505

stack backtrace:
CPU: 1 UID: 0 PID: 5828 Comm: syz-executor984 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079
 check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211
 check_prev_add kernel/locking/lockdep.c:3166 [inline]
 check_prevs_add kernel/locking/lockdep.c:3285 [inline]
 validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
 touch_wq_lockdep_map+0xc7/0x170 kernel/workqueue.c:3907
 __flush_workqueue+0x14c/0x1280 kernel/workqueue.c:3949
 ocfs2_shutdown_local_alloc+0x10b/0xab0 fs/ocfs2/localalloc.c:380
 ocfs2_dismount_volume+0x204/0x910 fs/ocfs2/super.c:1822
 generic_shutdown_super+0x139/0x2d0 fs/super.c:642
 kill_block_super+0x44/0x90 fs/super.c:1710
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x422/0x4c0 fs/namespace.c:1435
 task_work_run+0x251/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa11/0x27f0 kernel/exit.c:953
 do_group_exit+0x207/0x2c0 kernel/exit.c:1102
 __do_sys_exit_group kernel/exit.c:1113 [inline]
 __se_sys_exit_group kernel/exit.c:1111 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111
 x64_sys_call+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faff12b9389
Code: Unable to access opcode bytes at 0x7faff12b935f.
RSP: 002b:00007ffdb0706938 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007faff12b9389
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007faff13472b0 R08: ffffffffffffffb0 R09: 0000000000000000
R10: 00007ffdb07069c0 R11: 0000000000000246 R12: 00007faff13472b0
R13: 0000000000000000 R14: 00007faff1348120 R15: 00007faff12844b0