============================================
WARNING: possible recursive locking detected
5.15.189-syzkaller #0 Not tainted
--------------------------------------------
kworker/u4:6/1712 is trying to acquire lock:
ffff0000c2d140b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1

but task is already holding lock:
ffff0000c2d140b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 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/u4:6/1712:
 #0: ffff0000c0b78138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x678/0x1140 kernel/workqueue.c:2283
 #1: ffff800023b47c00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6b8/0x1140 kernel/workqueue.c:2285
 #2: ffff0000c2d140b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1
 #3: ffff0000eb59a178 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xd8/0x1000 fs/hfs/extent.c:397

stack backtrace:
CPU: 0 PID: 1712 Comm: kworker/u4:6 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: writeback wb_workfn (flush-7:2)
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 dump_stack+0x1c/0x5c lib/dump_stack.c:113
 __lock_acquire+0x18a4/0x651c kernel/locking/lockdep.c:-1
 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743
 hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x250/0x1000 fs/hfs/extent.c:401
 hfs_bmap_reserve+0xd4/0x3e0 fs/hfs/btree.c:231
 __hfs_ext_write_extent+0x19c/0x488 fs/hfs/extent.c:121
 hfs_ext_write_extent+0x144/0x1bc fs/hfs/extent.c:144
 hfs_write_inode+0xbc/0x880 fs/hfs/inode.c:432
 write_inode fs/fs-writeback.c:1495 [inline]
 __writeback_single_inode+0x560/0x11f0 fs/fs-writeback.c:1705
 writeback_sb_inodes+0x7fc/0x1378 fs/fs-writeback.c:1930
 wb_writeback+0x3d8/0xe44 fs/fs-writeback.c:2104
 wb_do_writeback fs/fs-writeback.c:2247 [inline]
 wb_workfn+0x350/0xdd8 fs/fs-writeback.c:2288
 process_one_work+0x79c/0x1140 kernel/workqueue.c:2310
 worker_thread+0x8f4/0x101c kernel/workqueue.c:2457
 kthread+0x374/0x454 kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:855