On Thu, Apr 19, 2018 at 09:51:16AM +0800, jianchao.wang wrote: > Hi Ming > > Thanks for your kindly response. > > On 04/18/2018 11:40 PM, Ming Lei wrote: > >> Regarding to this patchset, it is mainly to fix the dependency between > >> nvme_timeout and nvme_dev_disable, as your can see: > >> nvme_timeout will invoke nvme_dev_disable, and nvme_dev_disable have to > >> depend on nvme_timeout when controller no response. > > Do you mean nvme_disable_io_queues()? If yes, this one has been handled > > by wait_for_completion_io_timeout() already, and looks the block timeout > > can be disabled simply. Or are there others? > > > Here is one possible scenario currently > > nvme_dev_disable // hold shutdown_lock nvme_timeout > -> nvme_set_host_mem -> nvme_dev_disable > -> nvme_submit_sync_cmd -> try to require > shutdown_lock > -> __nvme_submit_sync_cmd > -> blk_execute_rq > //if sysctl_hung_task_timeout_secs == 0 > -> wait_for_completion_io > And maybe nvme_dev_disable need to issue other commands in the future.
OK, thanks for sharing this one, for now I think it might need to be handled by wait_for_completion_io_timeout() for working around this issue. > > Even if we could fix these kind of issues as nvme_disable_io_queues, > it is still a risk I think. Yeah, I can't agree more, that is why I think the nvme time/eh code should be refactored, and solve the current issues in a more clean/maintainable way. Thanks, Ming
