syzbot

============================================
WARNING: possible recursive locking detected
6.2.0-rc5-syzkaller #0 Not tainted
--------------------------------------------
kworker/u4:3/49 is trying to acquire lock:
ffff8880289280b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x167/0x1e0

but task is already holding lock:
ffff8880289280b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x167/0x1e0

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/u4:3/49:
 #0: ffff8881451eb138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7f2/0xdb0
 #1: ffffc90000ba7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x831/0xdb0 kernel/workqueue.c:2264
 #2: ffff8880289280b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x167/0x1e0
 #3: ffff888079f380f8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xde/0x1420 fs/hfs/extent.c:397

stack backtrace:
CPU: 0 PID: 49 Comm: kworker/u4:3 Not tainted 6.2.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline]
 check_deadlock kernel/locking/lockdep.c:3033 [inline]
 validate_chain+0x4843/0x6ae0 kernel/locking/lockdep.c:3818
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
 __mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
 hfs_find_init+0x167/0x1e0
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x2f8/0x1420 fs/hfs/extent.c:401
 hfs_bmap_reserve+0xfa/0x410 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x1ea/0x460 fs/hfs/extent.c:121
 hfs_ext_write_extent+0x13e/0x1b0 fs/hfs/extent.c:144
 hfs_write_inode+0x8d/0xaf0 fs/hfs/inode.c:431
 write_inode fs/fs-writeback.c:1451 [inline]
 __writeback_single_inode+0x4d6/0x670 fs/fs-writeback.c:1663
 writeback_sb_inodes+0x812/0x1050 fs/fs-writeback.c:1889
 wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2063
 wb_do_writeback fs/fs-writeback.c:2206 [inline]
 wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2246
 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
 kthread+0x266/0x300 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>