nvme: flush namespace scanning work just before removing namespaces

nvme_stop_ctrl can be called also for reset flow and there is no need to
flush the scan_work as namespaces are not being removed. This can cause
deadlock in rdma, fc and loop drivers since nvme_stop_ctrl barriers
before controller teardown (and specifically I/O cancellation of the
scan_work itself) takes place, but the scan_work will be blocked anyways
so there is no need to flush it.

Instead, move scan_work flush to nvme_remove_namespaces() where it really
needs to flush.

Reported-by: Ming Lei <[email protected]>
Signed-off-by: Sagi Grimberg <[email protected]>
Reviewed-by: Keith Busch <[email protected]>
Reviewed by: James Smart <[email protected]>
Tested-by: Ewan D. Milne <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
This commit is contained in:
Sagi Grimberg 2018-11-21 15:17:37 -08:00 • committed by Christoph Hellwig
commit f6c8e432cb

View file

@ -3314,6 +3314,9 @@ void nvme_remove_namespaces(struct nvme_ctrl *ctrl)
struct nvme_ns *ns, *next;
LIST_HEAD(ns_list);
/* prevent racing with ns scanning */
flush_work(&ctrl->scan_work);
/*
* The dead states indicates the controller was not gracefully
* disconnected. In that case, we won't be able to flush any data while
@ -3476,7 +3479,6 @@ void nvme_stop_ctrl(struct nvme_ctrl *ctrl)
nvme_mpath_stop(ctrl);
nvme_stop_keep_alive(ctrl);
flush_work(&ctrl->async_event_work);
flush_work(&ctrl->scan_work);
cancel_work_sync(&ctrl->fw_act_work);
if (ctrl->ops->stop_ctrl)
ctrl->ops->stop_ctrl(ctrl);