============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.1.7/5742 is trying to acquire lock:
ffff88810cad00a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300

but task is already holding lock:
ffff88810cad00a8 (&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.1.7/5742:
 #0: ffff888118fda410 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x227/0xb90
 #1: ffff888012129c90 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x11e/0x680
 #2: ffff888012129af0 (&HFS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0
 #3: ffff88810cad00a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfs_find_init+0x18e/0x300
 #4: ffff88801212ae70 (&HFS_I(tree->inode)->extents_lock){+.+.}-{4:4}, at: hfs_extend_file+0xf2/0x15e0

stack backtrace:
CPU: 0 UID: 0 PID: 5742 Comm: syz.1.7 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+0x253f/0x2cf0
 lock_acquire+0x106/0x350
 __mutex_lock+0x1a3/0x1550
 hfs_find_init+0x18e/0x300
 hfs_extend_file+0x35c/0x15e0
 hfs_bmap_reserve+0x107/0x430
 __hfs_ext_write_extent+0x1fa/0x470
 __hfs_ext_cache_extent+0x6b/0x9b0
 hfs_extend_file+0x39b/0x15e0
 hfs_get_block+0x412/0xc50
 __block_write_begin_int+0x6c6/0x1910
 cont_write_begin+0x737/0xae0
 hfs_write_begin+0x66/0xb0
 cont_write_begin+0x2e7/0xae0
 hfs_write_begin+0x66/0xb0
 generic_perform_write+0x2e2/0x8f0
 generic_file_write_iter+0x14a/0x680
 vfs_write+0x61d/0xb90
 __x64_sys_pwrite64+0x199/0x230
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb67f9cdd9
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:00007fdb68df2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007fdb68215fa0 RCX: 00007fdb67f9cdd9
RDX: 0000000000000003 RSI: 0000200000000080 RDI: 0000000000000007
RBP: 00007fdb68032d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008000c61 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdb68216038 R14: 00007fdb68215fa0 R15: 00007ffefb4e0828
 </TASK>
