======================================================
WARNING: possible circular locking dependency detected
6.12.0-next-20241128-syzkaller #0 Not tainted
------------------------------------------------------
btrfs-cleaner/7238 is trying to acquire lock:
ffff88807c3c2e18 (&delayed_node->mutex){+.+.}-{4:4}, at: __btrfs_release_delayed_node+0xa5/0xaf0 fs/btrfs/delayed-inode.c:268

but task is already holding lock:
ffff88805d870e18 (btrfs-tree-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (btrfs-tree-00){++++}-{4:4}:
       reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374
       __lock_release kernel/locking/lockdep.c:5563 [inline]
       lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870
       up_read+0x16/0x20 kernel/locking/rwsem.c:1619
       btrfs_tree_unlock_rw fs/btrfs/locking.h:203 [inline]
       btrfs_search_slot+0xd50/0x3150 fs/btrfs/ctree.c:2179
       btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:411
       __btrfs_update_delayed_inode+0x1e7/0xb90 fs/btrfs/delayed-inode.c:1030
       btrfs_update_delayed_inode fs/btrfs/delayed-inode.c:1114 [inline]
       __btrfs_commit_inode_delayed_items+0x2318/0x24a0 fs/btrfs/delayed-inode.c:1137
       __btrfs_run_delayed_items+0x213/0x490 fs/btrfs/delayed-inode.c:1171
       flush_space+0x24a/0xcf0 fs/btrfs/space-info.c:775
       btrfs_async_reclaim_metadata_space+0x113/0x350 fs/btrfs/space-info.c:1105
       process_one_work kernel/workqueue.c:3229 [inline]
       process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310
       worker_thread+0x870/0xd30 kernel/workqueue.c:3391
       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 (&delayed_node->mutex){+.+.}-{4:4}:
       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
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
       __btrfs_release_delayed_node+0xa5/0xaf0 fs/btrfs/delayed-inode.c:268
       btrfs_evict_inode+0x752/0x1080 fs/btrfs/inode.c:5374
       evict+0x4e8/0x9a0 fs/inode.c:796
       btrfs_read_locked_inode+0x1027/0x1570 fs/btrfs/inode.c:3996
       btrfs_iget+0x1ca/0x2b0 fs/btrfs/inode.c:5612
       btrfs_run_defrag_inode fs/btrfs/defrag.c:246 [inline]
       btrfs_run_defrag_inodes+0x6bb/0xe40 fs/btrfs/defrag.c:318
       cleaner_kthread+0x28c/0x3d0 fs/btrfs/disk-io.c:1525
       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
       ----                    ----
  rlock(btrfs-tree-00);
                               lock(&delayed_node->mutex);
                               lock(btrfs-tree-00);
  lock(&delayed_node->mutex);

 *** DEADLOCK ***

1 lock held by btrfs-cleaner/7238:
 #0: ffff88805d870e18 (btrfs-tree-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146

stack backtrace:
CPU: 1 UID: 0 PID: 7238 Comm: btrfs-cleaner Not tainted 6.12.0-next-20241128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
 __btrfs_release_delayed_node+0xa5/0xaf0 fs/btrfs/delayed-inode.c:268
 btrfs_evict_inode+0x752/0x1080 fs/btrfs/inode.c:5374
 evict+0x4e8/0x9a0 fs/inode.c:796
 btrfs_read_locked_inode+0x1027/0x1570 fs/btrfs/inode.c:3996
 btrfs_iget+0x1ca/0x2b0 fs/btrfs/inode.c:5612
 btrfs_run_defrag_inode fs/btrfs/defrag.c:246 [inline]
 btrfs_run_defrag_inodes+0x6bb/0xe40 fs/btrfs/defrag.c:318
 cleaner_kthread+0x28c/0x3d0 fs/btrfs/disk-io.c:1525
 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>