============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.2.306/8023 is trying to acquire lock:
ffff888170d2e0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300

but task is already holding lock:
ffff888170d2e0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300

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 syz.2.306/8023:
 #0: ffff888114084420 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90
 #1: ffff888175a9a320 (&sb->s_type->i_mutex_key#40){+.+.}-{4:4}, at: do_truncate+0x171/0x220
 #2: ffff888175a9a178 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1540
 #3: ffff888170d2e0b0 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300
 #4: ffff888175a99af8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xda/0x1540

stack backtrace:
CPU: 0 UID: 0 PID: 8023 Comm: syz.2.306 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_deadlock_bug+0x279/0x290
 __lock_acquire+0x2540/0x2cf0
 lock_acquire+0x107/0x340
 __mutex_lock+0x187/0x1350
 hfs_find_init+0x18e/0x300
 hfs_extend_file+0x2f6/0x1540
 hfs_bmap_reserve+0x107/0x430
 __hfs_ext_write_extent+0x1fa/0x470
 __hfs_ext_cache_extent+0x6b/0x9b0
 hfs_extend_file+0x31e/0x1540
 hfs_get_block+0x3d7/0xbd0
 __block_write_begin_int+0x6b5/0x1900
 cont_write_begin+0x78c/0xb50
 hfs_write_begin+0x66/0xb0
 cont_write_begin+0x2fd/0xb50
 hfs_write_begin+0x66/0xb0
 hfs_file_truncate+0x19c/0xb30
 hfs_inode_setattr+0x4a9/0x670
 notify_change+0xc1a/0xf40
 do_truncate+0x1a4/0x220
 vfs_truncate+0x493/0x520
 do_sys_truncate+0xdb/0x190
 __x64_sys_truncate+0x5b/0x70
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6e44f8f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6e45d92038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f6e451e5fa0 RCX: 00007f6e44f8f7c9
RDX: 0000000000000000 RSI: 0000000001001bfc RDI: 0000200000000040
RBP: 00007f6e44ff297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6e451e6038 R14: 00007f6e451e5fa0 R15: 00007ffe6390c018
 </TASK>
