BTRFS error (device loop0): allocation failed flags 4, wanted 4096 tree-log 0, relocation: 0
BTRFS info (device loop0): space_info DATA+METADATA (sub-group id 0) has -6914048 free, is full
BTRFS info (device loop0): space_info total=11534336, used=2936832, pinned=20480, reserved=8577024, may_use=6914048, readonly=0 zone_unusable=0
BTRFS info (device loop0): global_block_rsv: size 983040 reserved 983040
BTRFS info (device loop0): trans_block_rsv: size 0 reserved 0
BTRFS info (device loop0): chunk_block_rsv: size 0 reserved 0
BTRFS info (device loop0): remap_block_rsv: size 0 reserved 0
BTRFS info (device loop0): delayed_block_rsv: size 32768 reserved 32768
BTRFS info (device loop0): delayed_refs_rsv: size 5898240 reserved 5894144
BTRFS info (device loop0): block group 5242880 has 1638400 bytes, 1617920 used 20480 pinned 0 reserved 0 delalloc 0 super 0 zone_unusable (0 bytes available) 
BTRFS info (device loop0): block group has cluster?: no
BTRFS info (device loop0): 0 free space entries at or bigger than 4096 bytes
BTRFS info (device loop0): block group 6881280 has 1638400 bytes, 1318912 used 0 pinned 319488 reserved 0 delalloc 0 super 0 zone_unusable (0 bytes available) 
BTRFS info (device loop0): block group has cluster?: no
BTRFS info (device loop0): 0 free space entries at or bigger than 4096 bytes
BTRFS info (device loop0): block group 8519680 has 8257536 bytes, 0 used 0 pinned 8257536 reserved 0 delalloc 0 super 0 zone_unusable (0 bytes available) 
BTRFS info (device loop0): block group has cluster?: no
BTRFS info (device loop0): 0 free space entries at or bigger than 4096 bytes
BTRFS error (device loop0): failed to run delayed ref for logical 8200192 num_bytes 4096 type 176 action 1 ref_mod 1: -28
------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/extent-tree.c:2248 at btrfs_run_delayed_refs+0x292/0x2a0 fs/btrfs/extent-tree.c:2248, CPU#0: kworker/u4:5/75
Modules linked in:
CPU: 0 UID: 0 PID: 75 Comm: kworker/u4:5 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_data_space
RIP: 0010:btrfs_run_delayed_refs+0x292/0x2a0 fs/btrfs/extent-tree.c:2248
Code: c1 38 c1 0f 8c ea fd ff ff 4c 89 ef e8 e7 c4 25 fe e9 dd fd ff ff e8 9d 23 b4 fd eb 10 e8 96 23 b4 fd eb 09 e8 8f 23 b4 fd 90 <0f> 0b 90 44 89 e9 f7 d9 e9 71 ff ff ff 90 90 90 90 90 90 90 90 90
RSP: 0000:ffffc90000d47620 EFLAGS: 00010293
RAX: ffffffff8413d8b1 RBX: ffff888045520bc0 RCX: ffff8880003acb00
RDX: 0000000000000000 RSI: ffffffff8f3cfb90 RDI: 00000000ffffffe4
RBP: 0000000000000001 R08: ffff8880003acb00 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: ffff888012a7c000
R13: 00000000ffffffe4 R14: 00000000ffffffe4 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88808c2bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f35742f87e0 CR3: 000000001fc8a000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 btrfs_commit_transaction+0x28a/0x3170 fs/btrfs/transaction.c:2267
 flush_space+0x28a/0xde0 fs/btrfs/space-info.c:-1
 do_async_reclaim_data_space+0x29e/0x550 fs/btrfs/space-info.c:1471
 btrfs_async_reclaim_data_space+0x41/0x90 fs/btrfs/space-info.c:1519
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 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>