On Thu, May 10, 2018 at 03:01:04PM +0000, Bart Van Assche wrote: > On Sat, 2018-05-05 at 21:58 +0800, Ming Lei wrote: > > Turns out the current way can't drain timout completely because mod_timer() > > can be triggered in the work func, which can be just run inside the synced > > timeout work: > > > > del_timer_sync(&q->timeout); > > cancel_work_sync(&q->timeout_work); > > > > This patch introduces one flag of 'timeout_off' for fixing this issue, turns > > out this simple way does work. > > > > Also blk_quiesce_timeout() and blk_unquiesce_timeout() are introduced for > > draining timeout, which is needed by NVMe. > > Hello Ming, > > The description of the above patch does not motivate sufficiently why you think > that this change is necessary. As you know it is already possible to wait until > timeout handling has finished by calling blk_mq_freeze_queue() + > blk_mq_unfreeze_queue(). An explanation is needed of why you think that calling blk_mq_freeze_queue() + blk_mq_unfreeze_queue() can't work, you have to call blk_mq_freeze_queue_wait() between the two, but blk_mq_freeze_queue_wait is a big trouble for NVMe, and can't be used inside nvme_dev_disable(). You can find the usage in the last patch of this series. Thanks, Ming
