Comment 2 for bug 1798212

We just hit a similar issue on Ubuntu 18.04. From the crash dump, I'm able to see this stack:

[12929.914040] kworker/u4:5 D 0 27285 2 0x80000080
[12929.914053] Workqueue: events_unbound fsnotify_mark_destroy_workfn
[12929.914055] Call Trace:
[12929.914075] __schedule+0x291/0x8a0
[12929.914078] schedule+0x2c/0x80
[12929.914081] schedule_timeout+0x1cf/0x350
[12929.914086] ? select_idle_sibling+0x29/0x410
[12929.914089] ? __enqueue_entity+0x5c/0x60
[12929.914091] ? enqueue_entity+0x10e/0x6b0
[12929.914093] wait_for_completion+0xba/0x140
[12929.914094] ? wake_up_q+0x80/0x80
[12929.914099] __synchronize_srcu.part.13+0x85/0xb0
[12929.914101] ? trace_raw_output_rcu_utilization+0x50/0x50
[12929.914103] ? ttwu_do_activate+0x77/0x80
[12929.914105] synchronize_srcu+0x66/0xe0
[12929.914107] ? synchronize_srcu+0x66/0xe0
[12929.914109] fsnotify_mark_destroy_workfn+0x7b/0xe0
[12929.914113] process_one_work+0x1de/0x410
[12929.914115] worker_thread+0x228/0x410
[12929.914118] kthread+0x121/0x140
[12929.914119] ? process_one_work+0x410/0x410
[12929.914121] ? kthread_create_worker_on_cpu+0x70/0x70

Several other systemd processes are also hung. I was able to issue an NMI to generate a crash dump so I can pull out more information if that would be helpful.