Hi Keith On 06/20/2018 12:39 AM, Keith Busch wrote: > On Tue, Jun 19, 2018 at 04:30:50PM +0800, Jianchao Wang wrote: >> There is race between nvme_remove and nvme_reset_work that can >> lead to io hang. >> >> nvme_remove nvme_reset_work >> -> change state to DELETING >> -> fail to change state to LIVE >> -> nvme_remove_dead_ctrl >> -> nvme_dev_disable >> -> quiesce request_queue >> -> queue remove_work >> -> cancel_work_sync reset_work >> -> nvme_remove_namespaces >> -> splice ctrl->namespaces >> nvme_remove_dead_ctrl_work >> -> nvme_kill_queues >> -> nvme_ns_remove do nothing >> -> blk_cleanup_queue >> -> blk_freeze_queue >> Finally, the request_queue is quiesced state when wait freeze, >> we will get io hang here. >> >> In fact, when fails to change state in nvme_reset_work, the only >> reason is someone has changed state to DELETING. So it is not >> necessary to invoke nvme_remove_dead_ctrl in that case. >> >> Signed-off-by: Jianchao Wang <jianchao.w.w...@oracle.com> > > Good catch. I think the fix should either have the nvme_dev_disable set > shutdown to true to indicate the controller isn't coming back online, or > move the nvme_kill_queues inside nvme_remove_dead_ctrl.
Yes,just not invoking nvme_remove_dead_ctrl when change state fails couldn't fix the hole completely. I prefer to move nvme_kill_queues from nvme_remove_dead_ctrl_work to nvme_remove_dead_ctrl. Will post the V2 version based on this. Thanks Jianchao
