------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/block-group.c:4203 at do_chunk_alloc fs/btrfs/block-group.c:4203 [inline], CPU#0: kworker/u4:6/176
WARNING: fs/btrfs/block-group.c:4203 at btrfs_chunk_alloc+0x10cc/0x1330 fs/btrfs/block-group.c:4444, CPU#0: kworker/u4:6/176
Modules linked in:
CPU: 0 UID: 0 PID: 176 Comm: kworker/u4:6 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
Workqueue: events_unbound btrfs_async_reclaim_metadata_space
RIP: 0010:do_chunk_alloc fs/btrfs/block-group.c:4203 [inline]
RIP: 0010:btrfs_chunk_alloc+0x10cc/0x1330 fs/btrfs/block-group.c:4444
Code: 07 38 c1 0f 8c e9 ef ff ff 48 89 df e8 7d c5 fc fd e9 dc ef ff ff e8 13 a2 8d fd eb 10 e8 0c a2 8d fd eb 09 e8 05 a2 8d fd 90 <0f> 0b 90 44 89 f1 f7 d9 e9 38 fd ff ff 48 8b 4c 24 08 48 83 c1 5b
RSP: 0000:ffffc9000186f6f8 EFLAGS: 00010293
RAX: ffffffff8438e08b RBX: 1ffff1100a4db816 RCX: ffff8880332e4a80
RDX: 0000000000000000 RSI: ffffffff8f1fc240 RDI: 00000000ffffffe4
RBP: ffff888043b80001 R08: ffff8880332e4a80 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: 1ffff1100a4db816
R13: 00000000ffffffe4 R14: ffffffffffffffe4 R15: ffff8880526ea180
FS:  0000000000000000(0000) GS:ffff88808c54e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f5ef96000 CR3: 00000000439b2000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 flush_space+0x3df/0xde0 fs/btrfs/space-info.c:908
 do_async_reclaim_metadata_space+0x3e8/0x940 fs/btrfs/space-info.c:1211
 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1278
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>