loop0: detected capacity change from 0 to 1024
hfsplus: can't free extent: start 2889, count 1

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.0/5315 is trying to acquire lock:
ffff888051b38740 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21c/0x1df0 fs/hfsplus/extents.c:457

but task is already holding lock:
ffff888051b32040 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21c/0x1df0 fs/hfsplus/extents.c:457

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

locks held by syz.0.0/5315: 3, last CPU#0:
 #0: ffff888051b321d8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1025 [inline]
 #0: ffff888051b321d8 (&sb->s_type->i_mutex_key#23){+.+.}-{4:4}, at: generic_file_write_iter+0x82/0x330 mm/filemap.c:4514
 #1: ffff888051b32040 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21c/0x1df0 fs/hfsplus/extents.c:457
 #2: ffff88803542e0a8 (&tree->tree_lock/1){+.+.}-{4:4}, at: hfsplus_find_init+0x179/0x2e0 fs/hfsplus/bfind.c:29

stack backtrace:
CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
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
 hfsplus_file_extend+0x21c/0x1df0 fs/hfsplus/extents.c:457
 hfsplus_bmap_reserve+0x170/0x590 fs/hfsplus/btree.c:512
 __hfsplus_ext_write_extent+0x295/0x690 fs/hfsplus/extents.c:104
 __hfsplus_ext_cache_extent+0x81/0xbd0 fs/hfsplus/extents.c:190
 hfsplus_ext_read_extent fs/hfsplus/extents.c:222 [inline]
 hfsplus_file_extend+0x502/0x1df0 fs/hfsplus/extents.c:461
 hfsplus_get_block+0x41f/0x1610 fs/hfsplus/extents.c:249
 __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
 hfsplus_write_begin+0x126/0x1e0 fs/hfsplus/inode.c:56
 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374
 generic_file_write_iter+0xae/0x330 mm/filemap.c:4517
 aio_write+0x5d0/0x870 fs/aio.c:1687
 __io_submit_one fs/aio.c:-1 [inline]
 io_submit_one+0x798/0x13d0 fs/aio.c:2106
 __do_sys_io_submit fs/aio.c:2165 [inline]
 __se_sys_io_submit+0x195/0x340 fs/aio.c:2135
 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: 0033:0x7f630259e0d9
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:00007f6303477fe8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1
RAX: ffffffffffffffda RBX: 00007f6302825fa0 RCX: 00007f630259e0d9
RDX: 0000200000000540 RSI: 000000000000003b RDI: 00007f630342f000
RBP: 00007f6302635024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6302826038 R14: 00007f6302825fa0 R15: 00007fffbb4896a8
 </TASK>
Trying to write to read-only block-device loop0