INFO: task kworker/0:2:1325 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:2     state:D
 stack:25328 pid: 1325 ppid:     2 flags:0x00004000
Workqueue: events_long flush_old_commits
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
 reiserfs_sync_fs fs/reiserfs/super.c:76 [inline]
 flush_old_commits+0x1fb/0x310 fs/reiserfs/super.c:111
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/1:1/26:
 #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc90000e1fd00
 (
(work_completion)(&(&sbi->old_work)->work)
){+.+.}-{0:0}
, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: 
ffff8880757f00e0
 (
&type->s_umount_key
#53
){.+.+}-{3:3}
, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: 
ffff88805a498090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
1 lock held by khungtaskd/27:
 #0: ffffffff8c31f360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u4:2/154:
4 locks held by kworker/1:2/1108:
 #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc90004bc7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff88805a1f40e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: ffff88807c4d9090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
4 locks held by kworker/0:2/1325:
 #0: 
ffff888016c71138
 (
(wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc90004fb7d00
 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: ffff88807b2a00e0 (&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: ffff888076e04090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
4 locks held by kworker/1:3/2415:
 #0: 
ffff888016c71138
 (
(wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: ffffc9000664fd00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: 
ffff888023ea60e0
 (
&type->s_umount_key#53){.+.+}-{3:3}, at: flush_old_commits+0xce/0x310 fs/reiserfs/super.c:97
 #3: ffff888029d9e090
 (
&sbi->lock
){+.+.}-{3:3}
, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27
2 locks held by getty/3943:
 #0: 
ffff88814d2ba098
 (
&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: 
ffffc900025e62e8