BTRFS error (device loop0): allocation failed flags 2, wanted 4096 tree-log 0, relocation: 0
BTRFS info (device loop0): space_info SYSTEM (sub-group id 0) has -98304 free, is not full
BTRFS info (device loop0): space_info total=4194304, used=4096, pinned=0, reserved=0, may_use=98304, readonly=4190208 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 98304 reserved 94208
BTRFS info (device loop0): delayed_block_rsv: size 98304 reserved 98304
BTRFS info (device loop0): delayed_refs_rsv: size 229376 reserved 229376
BTRFS info (device loop0): block group 1048576 has 4194304 bytes, 4096 used 0 pinned 0 reserved 0 delalloc 0 super 0 zone_unusable (4190208 bytes available) [readonly]
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): 4190208 bytes available across all block groups
------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: CPU: 0 PID: 13 at fs/btrfs/block-group.c:3990 do_chunk_alloc fs/btrfs/block-group.c:3990 [inline]
WARNING: CPU: 0 PID: 13 at fs/btrfs/block-group.c:3990 btrfs_chunk_alloc+0xf4d/0x1150 fs/btrfs/block-group.c:4231
Modules linked in:
CPU: 0 UID: 0 PID: 13 Comm: kworker/u4:1 Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events_unbound btrfs_async_reclaim_metadata_space
RIP: 0010:do_chunk_alloc fs/btrfs/block-group.c:3990 [inline]
RIP: 0010:btrfs_chunk_alloc+0xf4d/0x1150 fs/btrfs/block-group.c:4231
Code: 48 c7 c6 80 b0 cf 8b 44 89 f2 e8 ee 54 42 fd e9 b5 fc ff ff e8 84 97 d8 fd 90 48 c7 c7 20 b0 cf 8b 44 89 f6 e8 a4 45 9c fd 90 <0f> 0b 90 90 e9 96 fc ff ff e8 65 97 d8 fd eb 05 e8 5e 97 d8 fd 48
RSP: 0018:ffffc900001f7778 EFLAGS: 00010246
RAX: 0a8f0b3828266100 RBX: 0000000000000000 RCX: ffff88801af30000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: 00000000ffffff01 R08: ffff88801fc24293 R09: 1ffff11003f84852
R10: dffffc0000000000 R11: ffffed1003f84853 R12: ffff888031cedb90
R13: ffff888052902800 R14: ffffffffffffffe4 R15: ffff888052f3c000
FS:  0000000000000000(0000) GS:ffff88808d255000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f644a128b60 CR3: 0000000053f35000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 flush_space+0x30b/0xcd0 fs/btrfs/space-info.c:861
 do_async_reclaim_metadata_space+0x144/0x390 fs/btrfs/space-info.c:1158
 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1226
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>