The patch hasn't made it into mainline from what I have seen, it looks like it died back in March waiting for feedback from additional kernel developers. From what I have gathered this is a deadlock scenario directly caused by pausing the resync while the system is under heavy write activity.
Donald Buczek provided a reproducer which is a shell script that generates a lot of write activity and pauses/resumes the raid scrubbing. And he also provided a workaround to get the stuck system running without reboot: echo active > /sys/block/md1/md/array_state I haven't tried the patch or any of this, I pretty much eliminated the trigger which is mdcheck_start & mdcheck_continue and went back to the 18.04 LTS way of scrubbing arrays (which is basically don't pause/interrupt it once it starts). I ran through a checkarray yesterday to 100%, no problems. Meanwhile since upgrading to 20.04 LTS it has hung almost every single time through 5.4, 5.8, and 5.11 kernels. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1942935 Title: kernel io hangs during mdcheck/resync To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-signed-hwe-5.11/+bug/1942935/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
