======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc3-syzkaller-00017-gf44d154d6e3d #0 Not tainted
------------------------------------------------------
syz.0.0/5341 is trying to acquire lock:
ffff888052da0128 (bcachefs_btree){+.+.}-{0:0}, at: trans_set_locked fs/bcachefs/btree_locking.h:194 [inline]
ffff888052da0128 (bcachefs_btree){+.+.}-{0:0}, at: __bch2_trans_relock+0x382/0x5f0 fs/bcachefs/btree_locking.c:785

but task is already holding lock:
ffff8880542e1548 (&c->fsck_error_msgs_lock){+.+.}-{4:4}, at: __bch2_fsck_err+0x3d4/0x1570 fs/bcachefs/error.c:282

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&c->fsck_error_msgs_lock){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
       __bch2_fsck_err+0x3d4/0x1570 fs/bcachefs/error.c:282
       bch2_check_alloc_hole_freespace+0x816/0x1180 fs/bcachefs/alloc_background.c:1278
       bch2_check_alloc_info+0x20f8/0x5330 fs/bcachefs/alloc_background.c:1547
       bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:191
       bch2_run_online_recovery_passes+0x85/0x150 fs/bcachefs/recovery_passes.c:212
       bch2_fsck_online_thread_fn+0x1da/0x410 fs/bcachefs/chardev.c:799
       thread_with_stdio_fn+0x5f/0x130 fs/bcachefs/thread_with_file.c:298
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (bcachefs_btree){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       trans_set_locked fs/bcachefs/btree_locking.h:194 [inline]
       __bch2_trans_relock+0x397/0x5f0 fs/bcachefs/btree_locking.c:785
       __bch2_fsck_err+0x12ab/0x1570 fs/bcachefs/error.c:363
       bch2_check_alloc_hole_freespace+0x816/0x1180 fs/bcachefs/alloc_background.c:1278
       bch2_check_alloc_info+0x20f8/0x5330 fs/bcachefs/alloc_background.c:1547
       bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:191
       bch2_run_online_recovery_passes+0x85/0x150 fs/bcachefs/recovery_passes.c:212
       bch2_fsck_online_thread_fn+0x1da/0x410 fs/bcachefs/chardev.c:799
       thread_with_stdio_fn+0x5f/0x130 fs/bcachefs/thread_with_file.c:298
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&c->fsck_error_msgs_lock);
                               lock(bcachefs_btree);
                               lock(&c->fsck_error_msgs_lock);
  lock(bcachefs_btree);

 *** DEADLOCK ***

3 locks held by syz.0.0/5341:
 #0: ffff888054280278 (&c->state_lock){++++}-{4:4}, at: bch2_run_online_recovery_passes+0x32/0x150 fs/bcachefs/recovery_passes.c:204
 #1: ffff888054284398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline]
 #1: ffff888054284398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline]
 #1: ffff888054284398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7e1/0xd30 fs/bcachefs/btree_iter.c:3228
 #2: ffff8880542e1548 (&c->fsck_error_msgs_lock){+.+.}-{4:4}, at: __bch2_fsck_err+0x3d4/0x1570 fs/bcachefs/error.c:282

stack backtrace:
CPU: 0 UID: 0 PID: 5341 Comm: syz.0.0 Not tainted 6.13.0-rc3-syzkaller-00017-gf44d154d6e3d #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 trans_set_locked fs/bcachefs/btree_locking.h:194 [inline]
 __bch2_trans_relock+0x397/0x5f0 fs/bcachefs/btree_locking.c:785
 __bch2_fsck_err+0x12ab/0x1570 fs/bcachefs/error.c:363
 bch2_check_alloc_hole_freespace+0x816/0x1180 fs/bcachefs/alloc_background.c:1278
 bch2_check_alloc_info+0x20f8/0x5330 fs/bcachefs/alloc_background.c:1547
 bch2_run_recovery_pass+0xf0/0x1e0 fs/bcachefs/recovery_passes.c:191
 bch2_run_online_recovery_passes+0x85/0x150 fs/bcachefs/recovery_passes.c:212
 bch2_fsck_online_thread_fn+0x1da/0x410 fs/bcachefs/chardev.c:799
 thread_with_stdio_fn+0x5f/0x130 fs/bcachefs/thread_with_file.c:298
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>