syzbot

============================================
WARNING: possible recursive locking detected
6.8.0-syzkaller-08951-gfe46a7dd189e #0 Not tainted
--------------------------------------------
kworker/u8:7/2410 is trying to acquire lock:
ffff8880225260b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x16e/0x200 fs/hfsplus/bfind.c:33

but task is already holding lock:
ffff8880225260b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x16e/0x200 fs/hfsplus/bfind.c:33

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

6 locks held by kworker/u8:7/2410:
 #0: ffff8880176ba948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229
 #1: ffffc90008cc7d80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1a60 kernel/workqueue.c:3230
 #2: ffff8880225240e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: super_trylock_shared+0x1e/0xf0 fs/super.c:561
 #3: ffff8880223e0e88 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_ext_write_extent+0x82/0x210 fs/hfsplus/extents.c:149
 #4: ffff8880225260b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x16e/0x200 fs/hfsplus/bfind.c:33
 #5: ffff8880223e0108 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1c1/0x1090 fs/hfsplus/extents.c:457

stack backtrace:
CPU: 0 PID: 2410 Comm: kworker/u8:7 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3856 [inline]
 __lock_acquire+0x20e6/0x3b30 kernel/locking/lockdep.c:5137
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
 hfsplus_find_init+0x16e/0x200 fs/hfsplus/bfind.c:33
 hfsplus_ext_read_extent+0x18f/0x250 fs/hfsplus/extents.c:216
 hfsplus_file_extend+0x699/0x1090 fs/hfsplus/extents.c:461
 hfsplus_bmap_reserve+0x31c/0x410 fs/hfsplus/btree.c:358
 __hfsplus_ext_write_extent+0x474/0x5e0 fs/hfsplus/extents.c:104
 hfsplus_ext_write_extent_locked fs/hfsplus/extents.c:139 [inline]
 hfsplus_ext_write_extent_locked fs/hfsplus/extents.c:129 [inline]
 hfsplus_ext_write_extent+0x1c9/0x210 fs/hfsplus/extents.c:150
 hfsplus_write_inode+0x22/0x4f0 fs/hfsplus/super.c:154
 write_inode fs/fs-writeback.c:1498 [inline]
 __writeback_single_inode+0xa9d/0xe90 fs/fs-writeback.c:1715
 writeback_sb_inodes+0x5a6/0x1090 fs/fs-writeback.c:1941
 __writeback_inodes_wb+0xff/0x2e0 fs/fs-writeback.c:2012
 wb_writeback+0x7db/0xa90 fs/fs-writeback.c:2119
 wb_check_background_flush fs/fs-writeback.c:2189 [inline]
 wb_do_writeback fs/fs-writeback.c:2277 [inline]
 wb_workfn+0x856/0xe90 fs/fs-writeback.c:2304
 process_one_work+0x9ac/0x1a60 kernel/workqueue.c:3254
 process_scheduled_works kernel/workqueue.c:3335 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
 kthread+0x2c4/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>