============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/u4:6/4382 is trying to acquire lock:
ffff0000fe6400b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1

but task is already holding lock:
ffff0000fe6400b0 (&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/u4:6/4382:
 #0: ffff0000c2c2c138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x6b8/0x13a4 kernel/workqueue.c:2265
 #1: ffff800020af7c20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x6fc/0x13a4 kernel/workqueue.c:2267
 #2: ffff0000fe6400b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x148/0x1c8 fs/hfs/bfind.c:-1
 #3: ffff0000d96880f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xe4/0x1094 fs/hfs/extent.c:397

stack backtrace:
CPU: 0 PID: 4382 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Workqueue: writeback wb_workfn (flush-7:3)
Call trace:
 dump_backtrace+0x1c0/0x1ec 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
 __lock_acquire+0x15cc/0x6800 kernel/locking/lockdep.c:-1
 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662
 __mutex_lock_common+0x190/0x1f60 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+0x148/0x1c8 fs/hfs/bfind.c:-1
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x28c/0x1094 fs/hfs/extent.c:401
 hfs_bmap_reserve+0xd4/0x3e0 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x198/0x484 fs/hfs/extent.c:121
 hfs_ext_write_extent+0x154/0x1e0 fs/hfs/extent.c:144
 hfs_write_inode+0xf0/0x8dc fs/hfs/inode.c:434
 write_inode fs/fs-writeback.c:1470 [inline]
 __writeback_single_inode+0x5e0/0x1554 fs/fs-writeback.c:1687
 writeback_sb_inodes+0x858/0x143c fs/fs-writeback.c:1913
 wb_writeback+0x414/0xfcc fs/fs-writeback.c:2087
 wb_do_writeback fs/fs-writeback.c:2230 [inline]
 wb_workfn+0x360/0xe18 fs/fs-writeback.c:2270
 process_one_work+0x7f8/0x13a4 kernel/workqueue.c:2292
 worker_thread+0x8c4/0xfec kernel/workqueue.c:2439
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850