------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/free-space-tree.c:869 at btrfs_remove_from_free_space_tree+0xbcd/0xda0 fs/btrfs/free-space-tree.c:869, CPU#0: kworker/u4:2/24
Modules linked in:
CPU: 0 UID: 0 PID: 24 Comm: kworker/u4:2 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:btrfs_remove_from_free_space_tree+0xbcd/0xda0 fs/btrfs/free-space-tree.c:869
Code: e2 74 1a 41 83 ff fb 74 0d 41 83 ff f4 75 15 e8 29 c1 8c fd eb 17 e8 22 c1 8c fd eb 10 e8 1b c1 8c fd eb 09 e8 14 c1 8c fd 90 <0f> 0b 90 44 89 f9 f7 d9 49 bd 00 00 00 00 00 fc ff df e9 5d fe ff
RSP: 0018:ffffc9000031ef60 EFLAGS: 00010293
RAX: ffffffff843a73ac RBX: ffff888052270001 RCX: ffff88801b7b4b00
RDX: 0000000000000000 RSI: ffffffff8f3ffd50 RDI: 00000000ffffffe4
RBP: ffffc9000031f158 R08: ffff88801b7b4b00 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: 1ffff92000063df8
R13: dffffc0000000000 R14: ffff88801f5fb580 R15: 00000000ffffffe4
FS:  0000000000000000(0000) GS:ffff88808c30a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000007ff000 CR3: 000000000eb46000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 alloc_reserved_extent+0x4a/0x2b0 fs/btrfs/extent-tree.c:4976
 alloc_reserved_tree_block fs/btrfs/extent-tree.c:5155 [inline]
 run_delayed_tree_ref fs/btrfs/extent-tree.c:1815 [inline]
 run_one_delayed_ref fs/btrfs/extent-tree.c:1851 [inline]
 btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:2058 [inline]
 __btrfs_run_delayed_refs+0x18b5/0x43b0 fs/btrfs/extent-tree.c:2134
 btrfs_run_delayed_refs+0xdc/0x2a0 fs/btrfs/extent-tree.c:2246
 btrfs_commit_transaction+0x28a/0x30b0 fs/btrfs/transaction.c:2256
 flush_space+0x28a/0xde0 fs/btrfs/space-info.c:-1
 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:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 kthread+0x38b/0x480 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>