syzbot


INFO: task hung in write_all_supers

Status: auto-obsoleted due to no activity on 2025/10/07 22:48
Subsystems: btrfs
[Documentation on labels]
First crash: 94d, last: 94d

Sample crash report:
INFO: task kworker/u8:11:4453 blocked for more than 151 seconds.
      Not tainted 6.16.0-rc5-syzkaller-gec4801305969 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:11   state:D stack:0     pid:4453  tgid:4453  ppid:2      task_flags:0x4208060 flags:0x00000010
Workqueue: btrfs-qgroup-rescan btrfs_work_helper
Call trace:
 __switch_to+0x414/0x834 arch/arm64/kernel/process.c:742 (T)
 context_switch kernel/sched/core.c:5401 [inline]
 __schedule+0x1414/0x2a28 kernel/sched/core.c:6790
 __schedule_loop kernel/sched/core.c:6868 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:6883
 io_schedule+0x84/0xf0 kernel/sched/core.c:7728
 folio_wait_bit_common+0x56c/0x9e0 mm/filemap.c:1317
 folio_wait_bit+0x30/0x40 mm/filemap.c:1456
 folio_wait_locked include/linux/pagemap.h:1189 [inline]
 wait_dev_supers fs/btrfs/disk-io.c:3855 [inline]
 write_all_supers+0x2374/0x31c0 fs/btrfs/disk-io.c:4100
 btrfs_commit_transaction+0x19fc/0x2b44 fs/btrfs/transaction.c:2539
 btrfs_qgroup_rescan_worker+0x1164/0x150c fs/btrfs/qgroup.c:3852
 btrfs_work_helper+0x380/0xca8 fs/btrfs/async-thread.c:312
 process_one_work+0x7e8/0x155c kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x958/0xed8 kernel/workqueue.c:3402
 kthread+0x5fc/0x75c kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:843
INFO: task syz-executor:6532 blocked for more than 151 seconds.
      Not tainted 6.16.0-rc5-syzkaller-gec4801305969 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:6532  tgid:6532  ppid:6524   task_flags:0x400140 flags:0x00000010
Call trace:
 __switch_to+0x414/0x834 arch/arm64/kernel/process.c:742 (T)
 context_switch kernel/sched/core.c:5401 [inline]
 __schedule+0x1414/0x2a28 kernel/sched/core.c:6790
 __schedule_loop kernel/sched/core.c:6868 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:6883
 wait_for_commit+0x214/0x430 fs/btrfs/transaction.c:915
 btrfs_wait_for_commit+0x2d0/0x3c0 fs/btrfs/transaction.c:995
 btrfs_attach_transaction_barrier+0x74/0xac fs/btrfs/transaction.c:889
 btrfs_sync_fs+0x148/0x9a4 fs/btrfs/super.c:1010
 sync_filesystem+0x1a0/0x218 fs/sync.c:66

Showing all locks held in the system:
1 lock held by kthreadd/2:
2 locks held by kworker/0:1/11:
4 locks held by kworker/u8:0/12:
 #0: ffff0000d3394948 ((wq_completion)wg-kex-wg2#10){+.+.}-{0:0}, at: process_one_work+0x63c/0x155c kernel/workqueue.c:3212
 #1: ffff800097a87bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x6d4/0x155c kernel/workqueue.c:3212
 #2: ffff0000d9f2d308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x10c/0x6c8 drivers/net/wireguard/noise.c:529
 #3: ffff0000d2f7aad8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x114/0x6c8 drivers/net/wireguard/noise.c:530
3 locks held by kworker/u8:1/14:
1 lock held by khungtaskd/32:
 #0: ffff80008f8599c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
3 locks held by kworker/u8:2/41:

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/09 22:48 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci ec4801305969 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in write_all_supers
* Struck through repros no longer work on HEAD.