On Thu, Aug 05, 2021 at 06:14:18PM +0300, Pavel Skripkin wrote: > Syzbot reported task hung bug in ext4_fill_super(). The problem was in > too huge mmp update interval. > > Syzkaller reproducer setted s_mmp_update_interval to 39785 seconds. This > update interaval is unreasonable huge and it can cause tasks to hung on > kthread_stop() call, since it will wait until timeout timer expires. I must be missing something. kthread_stop() should wake up the kmmpd() thread, which should see kthread_should_stop(), and then it should exit. What is causing it to wait until the timeout timer expires? - Ted
