syzbot


INFO: task hung in start_transaction

Status: auto-obsoleted due to no activity on 2025/10/21 02:48
Subsystems: btrfs
[Documentation on labels]
First crash: 223d, last: 90d
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in start_transaction 1 1 569d 569d 0/3 auto-obsoleted due to no activity on 2024/07/09 10:14
linux-4.19 INFO: task hung in start_transaction btrfs 1 C 3 983d 1033d 0/1 upstream: reported C repro on 2022/12/23 07:52

Sample crash report:
INFO: task btrfs-transacti:9343 blocked for more than 151 seconds.
      Not tainted 6.16.0-rc7-syzkaller-g29e0a1d9558f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:btrfs-transacti state:D stack:0     pid:9343  tgid:9343  ppid:2      task_flags:0x208040 flags:0x00000010
Call trace:
 __switch_to+0x414/0x834 arch/arm64/kernel/process.c:741 (T)
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x141c/0x2a14 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:6879
 wait_current_trans+0x2d0/0x468 fs/btrfs/transaction.c:532
 start_transaction+0x798/0x155c fs/btrfs/transaction.c:707
 btrfs_attach_transaction+0x30/0x40 fs/btrfs/transaction.c:868
 transaction_kthread+0x1ac/0x430 fs/btrfs/disk-io.c:1583
 kthread+0x5fc/0x75c kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:843

Showing all locks held in the system:
1 lock held by kthreadd/2:
2 locks held by kworker/0:0/9:
2 locks held by kworker/0:1/11:
3 locks held by kworker/u8:0/12:
4 locks held by kworker/u8:1/13:
1 lock held by kworker/R-mm_pe/14:
 #0: ffff80008f7113c8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
3 locks held by kworker/1:0/24:
2 locks held by kworker/1:1/26:
1 lock held by khungtaskd/32:
 #0: ffff80008f869980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
1 lock held by kworker/R-write/34:
8 locks held by kworker/u8:2/41:
4 locks held by kworker/u8:3/42:
3 locks held by kworker/u8:4/196:
2 locks held by kworker/u8:5/291:
3 locks held by kworker/u8:6/307:
3 locks held by kworker/u8:7/322:
2 locks held by kworker/0:2/1815:
4 locks held by kworker/u8:8/2191:
4 locks held by kworker/R-bat_e/4252:
1 lock held by klogd/6129:
1 lock held by dhcpcd/6194:
1 lock held by dhcpcd/6195:
2 locks held by getty/6297:
 #0: ffff0000d232b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009ba3e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfa4 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/6513:
3 locks held by kworker/1:2/6524:
2 locks held by syz-executor/6531:
3 locks held by syz-executor/6533:
1 lock held by kworker/0:3/6534:

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/23 02:44 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 29e0a1d9558f 85deaf45 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in start_transaction
2025/06/10 02:05 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d7fa1af5b33e 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in start_transaction
2025/06/01 06:34 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d7fa1af5b33e 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in start_transaction
2025/05/13 02:40 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci c32f8dc5aaf9 f6671af7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in start_transaction
2025/03/12 08:19 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 5b4ec6e1eb76 ee70e6db .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in start_transaction
* Struck through repros no longer work on HEAD.