Hi,
I am writing to ask why jbd2 might freeze in kjournald2()?
I am asking this because since blk-mq commit bc27c01b5c46 (blk-mq: Do not
invoke .queue_rq() for a stopped queue), the I/O request will be queued
when the queue is stopped, that is, when OS is frozen (e.g., during xen
live migration or "echo freeze > /sys/power/state" in kvm guest). I think
it should be fine to not freeze jbd2.
Why would kjournald2() freeze to avoid submitting I/O?
Is it because of what is mentioned in code that "The simpler the better",
or there is any other reason?
Thank you very much!
Dongli Zhang