[v6.1] WARNING in btrfs_run_delayed_refs (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: da3c5173c55f Linux 6.1.140
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16adf9f4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2bfe5a2f04bb30e3
dashboard link: https://syzkaller.appspot.com/bug?extid=3d5206aaa0fac73fc0a5
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2c3ee4de68a1/disk-da3c5173.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/19742d73f52b/vmlinux-da3c5173.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0ffdd39d32ee/Image-da3c5173.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3d5206...@syzkaller.appspotmail.com

BTRFS error (device loop1): failed to run delayed ref for logical 5316608 num_bytes 4096 type 176 action 1 ref_mod 1: -28
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1592 at fs/btrfs/extent-tree.c:2165 btrfs_run_delayed_refs+0x404/0x47c fs/btrfs/extent-tree.c:2165
Modules linked in:
CPU: 0 PID: 1592 Comm: kworker/u4:5 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound btrfs_async_reclaim_metadata_space
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : btrfs_run_delayed_refs+0x404/0x47c fs/btrfs/extent-tree.c:2165
lr : btrfs_run_delayed_refs+0x404/0x47c fs/btrfs/extent-tree.c:2165
sp : ffff800024ff7910
x29: ffff800024ff7920 x28: ffff0000f2f1b000 x27: dfff800000000000
x26: 0000000000000003 x25: ffff0000d1ace070 x24: 1fffe0001ebdc3d8
x23: ffff0000f5ee1ec0 x22: 0000000000000000 x21: 00000000ffffffe4
x20: 0000000000000000 x19: ffff0000f5ee1e70 x18: ffff800011a7bd00
x17: 1fffe00033ee2f76 x16: ffff8000082d1c1c x15: 0000000040000000
x14: 0000000000000002 x13: 1ffff00002a0e0b1 x12: 0000000000ff0100
x11: ff0080000a889954 x10: 0000000000000003 x9 : 48cf7790e6471200
x8 : 48cf7790e6471200 x7 : ffff8000082516f8 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000007 x1 : ffff800011a7d800 x0 : ffff80018a752000
Call trace:
btrfs_run_delayed_refs+0x404/0x47c fs/btrfs/extent-tree.c:2165
flush_space+0x7ec/0xcdc fs/btrfs/space-info.c:744
btrfs_async_reclaim_metadata_space+0x25c/0x308 fs/btrfs/space-info.c:1080
process_one_work+0x7f4/0x13a8 kernel/workqueue.c:2292
worker_thread+0x8c8/0xfbc kernel/workqueue.c:2439
kthread+0x250/0x2d8 kernel/kthread.c:376
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:864
irq event stamp: 257700
hardirqs last enabled at (257699): [<ffff80000825178c>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1367 [inline]
hardirqs last enabled at (257699): [<ffff80000825178c>] finish_lock_switch+0xb0/0x1c4 kernel/sched/core.c:5003
hardirqs last disabled at (257700): [<ffff8000119153e0>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last enabled at (257644): [<ffff8000081a8dc0>] softirq_handle_end kernel/softirq.c:421 [inline]
softirqs last enabled at (257644): [<ffff8000081a8dc0>] handle_softirqs+0xaf8/0xc6c kernel/softirq.c:606
softirqs last disabled at (257525): [<ffff800008020164>] __do_softirq+0x14/0x20 kernel/softirq.c:612
---[ end trace 0000000000000000 ]---
BTRFS info (device loop1: state A): dumping space info:
BTRFS info (device loop1: state A): space_info DATA+METADATA has 2232320 free, is full
BTRFS info (device loop1: state A): space_info total=3276800, used=45056, pinned=16384, reserved=0, may_use=983040, readonly=0 zone_unusable=0
BTRFS info (device loop1: state A): space_info SYSTEM has 12447744 free, is not full
BTRFS info (device loop1: state A): space_info total=12451840, used=4096, pinned=0, reserved=0, may_use=0, readonly=0 zone_unusable=0
BTRFS info (device loop1: state A): global_block_rsv: size 983040 reserved 983040
BTRFS info (device loop1: state A): trans_block_rsv: size 0 reserved 0
BTRFS info (device loop1: state A): chunk_block_rsv: size 0 reserved 0
BTRFS info (device loop1: state A): delayed_block_rsv: size 0 reserved 0
BTRFS info (device loop1: state A): delayed_refs_rsv: size 0 reserved 0
BTRFS: error (device loop1: state A) in btrfs_run_delayed_refs:2165: errno=-28 No space left
BTRFS info (device loop1: state EA): forced readonly


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.