syzbot

============================================
WARNING: possible recursive locking detected
5.15.112-syzkaller #0 Not tainted
--------------------------------------------
kworker/u4:2/154 is trying to acquire lock:
ffff888078b6a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0

but task is already holding lock:
ffff888078b6a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0

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

5 locks held by kworker/u4:2/154:
 #0: ffff888014184938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2280
 #1: ffffc900010bfd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2282
 #2: ffff8880157f2988 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_ext_write_extent+0x8a/0x1f0 fs/hfsplus/extents.c:149
 #3: ffff888078b6a0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0
 #4: ffff8880157f0108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1d2/0x1b10 fs/hfsplus/extents.c:457

stack backtrace:
CPU: 0 PID: 154 Comm: kworker/u4:2 Not tainted 5.15.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2946 [inline]
 check_deadlock kernel/locking/lockdep.c:2989 [inline]
 validate_chain+0x46cf/0x58b0 kernel/locking/lockdep.c:3774
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5011
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622
 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 hfsplus_find_init+0x146/0x1c0
 hfsplus_ext_read_extent fs/hfsplus/extents.c:216 [inline]
 hfsplus_file_extend+0x40a/0x1b10 fs/hfsplus/extents.c:461
 hfsplus_bmap_reserve+0x101/0x4e0 fs/hfsplus/btree.c:357
 __hfsplus_ext_write_extent+0x2a4/0x5b0 fs/hfsplus/extents.c:104
 hfsplus_ext_write_extent_locked fs/hfsplus/extents.c:139 [inline]
 hfsplus_ext_write_extent+0x166/0x1f0 fs/hfsplus/extents.c:150
 hfsplus_write_inode+0x1e/0x5c0 fs/hfsplus/super.c:154
 write_inode fs/fs-writeback.c:1478 [inline]
 __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1683
 writeback_sb_inodes+0xbf0/0x1a50 fs/fs-writeback.c:1908
 wb_writeback+0x451/0xc50 fs/fs-writeback.c:2082
 wb_do_writeback fs/fs-writeback.c:2225 [inline]
 wb_workfn+0x46c/0x1130 fs/fs-writeback.c:2266
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>