syzbot


WARNING in __btrfs_free_extent (3)

Status: upstream: reported on 2025/06/01 18:33
Reported-by: syzbot+590ffb16e4cd9f630898@syzkaller.appspotmail.com
First crash: 7d03h, last: 6d17h
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in __btrfs_free_extent 6 8d22h 117d 0/3 upstream: reported on 2025/02/11 08:57
upstream WARNING in __btrfs_free_extent (2) btrfs C done 118 299d 350d 27/28 fixed on 2024/08/16 16:03
upstream WARNING in __btrfs_free_extent btrfs C error 300 390d 948d 25/28 fixed on 2024/05/22 09:57
linux-6.1 WARNING in __btrfs_free_extent (2) 2 225d 225d 0/3 auto-obsoleted due to no activity on 2025/02/03 04:58
linux-4.19 WARNING in __btrfs_free_extent btrfs C error 4 889d 907d 0/1 upstream: reported C repro on 2022/12/14 03:41
linux-6.1 WARNING in __btrfs_free_extent 1 377d 377d 0/3 auto-obsoleted due to no activity on 2024/09/04 10:24
upstream WARNING in __btrfs_free_extent (3) btrfs 41 19h14m 281d 0/28 upstream: reported on 2024/08/31 17:59

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4616 at fs/btrfs/extent-tree.c:3092 __btrfs_free_extent+0x1880/0x2320 fs/btrfs/extent-tree.c:3092
Modules linked in:
CPU: 0 PID: 4616 Comm: kworker/u4:14 Not tainted 6.1.140-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound btrfs_async_reclaim_metadata_space
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __btrfs_free_extent+0x1880/0x2320 fs/btrfs/extent-tree.c:3092
lr : __btrfs_free_extent+0x1880/0x2320 fs/btrfs/extent-tree.c:3092
sp : ffff8000211d7460
x29: ffff8000211d7580 x28: ffff0000f49949d8 x27: 0000000000000000
x26: 0000000000520000 x25: fffffffffffffff7 x24: 0000000000000000
x23: dfff800000000000 x22: 00000000ffffffe4 x21: dfff800000000000
x20: 0000000000000000 x19: 0000000000000000 x18: ffff800011a7bd00
x17: 1fffe00033ee2f76 x16: ffff8000082d1c1c x15: 0000000040000000
x14: 0000000000000002 x13: 1ffff00002a0e0b1 x12: 0000000000ff0100
x11: ff0080000a889954 x10: 0000000000000003 x9 : d05b773462b56e00
x8 : d05b773462b56e00 x7 : ffff8000082516f8 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000006 x1 : ffff800011a7d800 x0 : ffff80018a752000
Call trace:
 __btrfs_free_extent+0x1880/0x2320 fs/btrfs/extent-tree.c:3092
 run_delayed_tree_ref fs/btrfs/extent-tree.c:1696 [inline]
 run_one_delayed_ref fs/btrfs/extent-tree.c:1720 [inline]
 btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:1969 [inline]
 __btrfs_run_delayed_refs+0xba4/0x3280 fs/btrfs/extent-tree.c:2032
 btrfs_run_delayed_refs+0x124/0x47c fs/btrfs/extent-tree.c:2163
 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: 2534410
hardirqs last  enabled at (2534409): [<ffff80000825178c>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1367 [inline]
hardirqs last  enabled at (2534409): [<ffff80000825178c>] finish_lock_switch+0xb0/0x1c4 kernel/sched/core.c:5003
hardirqs last disabled at (2534410): [<ffff8000119153e0>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:405
softirqs last  enabled at (2534396): [<ffff8000081a8dc0>] softirq_handle_end kernel/softirq.c:421 [inline]
softirqs last  enabled at (2534396): [<ffff8000081a8dc0>] handle_softirqs+0xaf8/0xc6c kernel/softirq.c:606
softirqs last disabled at (2534249): [<ffff800008020164>] __do_softirq+0x14/0x20 kernel/softirq.c:612
---[ end trace 0000000000000000 ]---
BTRFS info (device loop7: state A): dumping space info:
BTRFS info (device loop7: state A): space_info DATA+METADATA has 2166784 free, is full
BTRFS info (device loop7: state A): space_info total=3276800, used=53248, pinned=8192, reserved=0, may_use=1048576, readonly=0 zone_unusable=0
BTRFS info (device loop7: state A): space_info SYSTEM has 12447744 free, is not full
BTRFS info (device loop7: state A): space_info total=12451840, used=4096, pinned=0, reserved=0, may_use=0, readonly=0 zone_unusable=0
BTRFS info (device loop7: state A): global_block_rsv: size 983040 reserved 983040
BTRFS info (device loop7: state A): trans_block_rsv: size 0 reserved 0
BTRFS info (device loop7: state A): chunk_block_rsv: size 0 reserved 0
BTRFS info (device loop7: state A): delayed_block_rsv: size 0 reserved 0
BTRFS info (device loop7: state A): delayed_refs_rsv: size 65536 reserved 65536
BTRFS: error (device loop7: state A) in __btrfs_free_extent:3092: errno=-28 No space left
BTRFS info (device loop7: state EA): forced readonly
BTRFS error (device loop7: state EA): failed to run delayed ref for logical 5373952 num_bytes 4096 type 176 action 2 ref_mod 1: -28
BTRFS: error (device loop7: state EA) in btrfs_run_delayed_refs:2165: errno=-28 No space left

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/02 05:21 linux-6.1.y da3c5173c55f 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in __btrfs_free_extent
2025/06/01 18:32 linux-6.1.y da3c5173c55f 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in __btrfs_free_extent
* Struck through repros no longer work on HEAD.