syzbot


INFO: task hung in bch2_journal_reclaim_thread

Status: auto-obsoleted due to no activity on 2024/09/06 07:24
Subsystems: bcachefs
[Documentation on labels]
First crash: 82d, last: 82d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in bch2_journal_reclaim_thread (2) bcachefs 421 28m 7d08h 0/28 upstream: reported on 2024/09/21 08:21

Sample crash report:
INFO: task bch-reclaim/loo:19444 blocked for more than 144 seconds.
      Not tainted 6.10.0-rc6-next-20240703-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:bch-reclaim/loo state:D stack:28984 pid:19444 tgid:19444 ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6600
 __schedule_loop kernel/sched/core.c:6677 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6692
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6749
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 bch2_journal_reclaim_thread+0x167/0x560 fs/bcachefs/journal_reclaim.c:726
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:1/9:
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3199 [inline]
 #0: ffff888015080948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3305
 #1: ffffc900000e7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3200 [inline]
 #1: ffffc900000e7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3305
 #2: ffffffff8f5ff788 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
1 lock held by khungtaskd/30:
 #0: ffffffff8e335860 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:333 [inline]
 #0: ffffffff8e335860 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:845 [inline]
 #0: ffffffff8e335860 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6704
2 locks held by getty/4853:
 #0: ffff88802d1280a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211
5 locks held by kworker/u8:15/16915:
 #0: ffff888015edd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3199 [inline]
 #0: ffff888015edd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3305
 #1: ffffc900149a7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3200 [inline]
 #1: ffffc900149a7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3305
 #2: ffffffff8f5f2c10 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
 #3: ffffffff8f5ff788 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe9/0xa90 net/core/dev.c:11887
 #4: ffffffff8e33ac38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #4: ffffffff8e33ac38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:980
2 locks held by kworker/u8:18/16922:
8 locks held by syz.3.1922/19422:
1 lock held by bch-reclaim/loo/19444:
 #0: ffff88808f4caf28 (&j->reclaim_lock){+.+.}-{3:3}, at: bch2_journal_reclaim_thread+0x167/0x560 fs/bcachefs/journal_reclaim.c:726
7 locks held by syz-executor/20702:
 #0: ffff88802a0f6420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2876 [inline]
 #0: ffff88802a0f6420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586
 #1: ffff888023437888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x500 fs/kernfs/file.c:325
 #2: ffff888022e2c698 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x500 fs/kernfs/file.c:326
 #3: ffffffff8ef05248 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216
 #4: ffff88806b36c0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline]
 #4: ffff88806b36c0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1094 [inline]
 #4: ffff88806b36c0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1292
 #5: ffff88806b36d250 (&devlink->lock_key#93){+.+.}-{3:3}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672
 #6: ffffffff8f5ff788 (rtnl_mutex){+.+.}-{3:3}, at: unregister_nexthop_notifier+0x17/0x40 net/ipv4/nexthop.c:3899
1 lock held by syz-executor/20816:
 #0: ffffffff8f5ff788 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:149 [inline]
 #0: ffffffff8f5ff788 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x847/0x1180 net/core/rtnetlink.c:6725

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.10.0-rc6-next-20240703-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16926 Comm: kworker/u8:20 Not tainted 6.10.0-rc6-next-20240703-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:__lock_acquire+0x126e/0x2000 kernel/locking/lockdep.c:5190
Code: 24 28 0f b6 04 38 84 c0 0f 85 fb 09 00 00 48 8b 44 24 10 8b 18 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 80 07 01 93 <be> 08 00 00 00 e8 38 d2 8a 00 48 0f a3 1d 50 88 91 11 73 1d 48 69
RSP: 0018:ffffc90014a378f0 EFLAGS: 00000047
RAX: 0000000000000000 RBX: 0000000000000021 RCX: ffffffff816f7bd0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff93010780
RBP: eec21a7795f9227d R08: ffffffff9301085f R09: 1ffffffff260210b
R10: dffffc0000000000 R11: fffffbfff260210c R12: ffff88804b351e00
R13: ffff88804b3528d8 R14: 1ffff1100966a52a R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001680 CR3: 000000000e132000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5816
 rcu_lock_acquire include/linux/rcupdate.h:333 [inline]
 rcu_read_lock include/linux/rcupdate.h:845 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719
 process_one_work kernel/workqueue.c:3224 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3305
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3383
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/08 07:24 linux-next 0b58e108042b bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in bch2_journal_reclaim_thread
* Struck through repros no longer work on HEAD.