loop1: rw=1, sector=172, nr_sectors = 1 limit=64
Buffer I/O error on dev loop1, logical block 172, lost async page write
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/u4:5/4418 is trying to acquire lock:
ffff0000d55420b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x14c/0x1cc fs/hfs/bfind.c:-1

but task is already holding lock:
ffff0000d55420b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x14c/0x1cc fs/hfs/bfind.c:-1

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&tree->tree_lock/1);
  lock(&tree->tree_lock/1);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by kworker/u4:5/4418:
 #0: ffff0000c2c34138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x69c/0x13bc kernel/workqueue.c:-1
 #1: ffff800022187c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6e8/0x13bc kernel/workqueue.c:2267
 #2: ffff0000d55420b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x14c/0x1cc fs/hfs/bfind.c:-1
 #3: ffff0000f8781368 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x100c fs/hfs/extent.c:397

stack backtrace:
CPU: 1 PID: 4418 Comm: kworker/u4:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026
Workqueue: writeback wb_workfn (flush-7:1)
Call trace:
 dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 print_deadlock_bug+0x454/0x5c8 kernel/locking/lockdep.c:3040
 check_deadlock kernel/locking/lockdep.c:3090 [inline]
 validate_chain kernel/locking/lockdep.c:3884 [inline]
 __lock_acquire+0x6020/0x7280 kernel/locking/lockdep.c:5171
 lock_acquire+0x210/0x63c kernel/locking/lockdep.c:5790
 __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 hfs_find_init+0x14c/0x1cc fs/hfs/bfind.c:-1
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x25c/0x100c fs/hfs/extent.c:401
 hfs_bmap_reserve+0xdc/0x3a8 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x19c/0x480 fs/hfs/extent.c:121
 hfs_ext_write_extent+0x154/0x1e0 fs/hfs/extent.c:144
 hfs_write_inode+0xf0/0x8e8 fs/hfs/inode.c:431
 write_inode fs/fs-writeback.c:1536 [inline]
 __writeback_single_inode+0x5e0/0x157c fs/fs-writeback.c:1753
 writeback_sb_inodes+0x870/0x1470 fs/fs-writeback.c:1979
 wb_writeback+0x40c/0xfdc fs/fs-writeback.c:2153
 wb_do_writeback fs/fs-writeback.c:2296 [inline]
 wb_workfn+0x360/0xe18 fs/fs-writeback.c:2336
 process_one_work+0x7e4/0x13bc kernel/workqueue.c:2292
 worker_thread+0x8cc/0xfe8 kernel/workqueue.c:2439
 kthread+0x254/0x2e0 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850