Messages in this thread | | | Subject | Re: PATCH V4 0/5 nvme-pci: fixes on nvme_timeout and nvme_dev_disable | From | "jianchao.wang" <> | Date | Thu, 19 Apr 2018 09:51:16 +0800 |
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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.
Even if we could fix these kind of issues as nvme_disable_io_queues, it is still a risk I think.
Thanks Jianchao
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