============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.1.9235/28000 is trying to acquire lock:
ffff8880493300a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1

but task is already holding lock:
ffff8880493300a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 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

locks held by syz.1.9235/28000: 5, last CPU#0:
 #0: ffff88802b83a460 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff888052df8800 (&sb->s_type->i_mutex_key#49){+.+.}-{4:4}, at: inode_lock_killable include/linux/fs.h:1030 [inline]
 #1: ffff888052df8800 (&sb->s_type->i_mutex_key#49){+.+.}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63
 #2: ffff888052df8660 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397
 #3: ffff8880493300a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1
 #4: ffff888052df91e0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf9/0x1680 fs/hfs/extent.c:397

stack backtrace:
CPU: 0 UID: 0 PID: 28000 Comm: syz.1.9235 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3057
 check_deadlock kernel/locking/lockdep.c:3109 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x24df/0x2cf0 kernel/locking/lockdep.c:5253
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
 hfs_find_init+0x18d/0x300 fs/hfs/bfind.c:-1
 hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
 hfs_extend_file+0x367/0x1680 fs/hfs/extent.c:401
 hfs_bmap_reserve+0x108/0x430 fs/hfs/btree.c:399
 __hfs_ext_write_extent+0x1fc/0x470 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x6e/0x9b0 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x3ad/0x1680 fs/hfs/extent.c:401
 hfs_get_block+0x401/0xbf0 fs/hfs/extent.c:353
 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030
 block_write_begin fs/buffer.c:2144 [inline]
 cont_write_begin+0x71b/0xac0 fs/buffer.c:2506
 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62
 cont_expand_zero fs/buffer.c:2434 [inline]
 cont_write_begin+0x2d6/0xac0 fs/buffer.c:2496
 hfs_write_begin+0x123/0x1c0 fs/hfs/inode.c:62
 hfs_file_truncate+0x1d2/0xb70 fs/hfs/extent.c:495
 hfs_inode_setattr+0x4a3/0x6d0 fs/hfs/inode.c:688
 notify_change+0xbba/0xea0 fs/attr.c:556
 do_truncate+0x1c2/0x250 fs/open.c:68
 vfs_truncate+0x4b4/0x540 fs/open.c:118
 ksys_truncate+0xf3/0x1c0 fs/open.c:142
 __do_sys_truncate fs/open.c:154 [inline]
 __se_sys_truncate fs/open.c:152 [inline]
 __x64_sys_truncate+0x5b/0x70 fs/open.c:152
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0c3cb9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0c3da2e028 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f0c3ce25fa0 RCX: 00007f0c3cb9e0d9
RDX: 0000000000000000 RSI: 0000000001000707 RDI: 0000200000000340
RBP: 00007f0c3cc35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c3ce26038 R14: 00007f0c3ce25fa0 R15: 00007ffcf3853c38
 </TASK>