Re: [PATCH v7 2/3] nvme-fc: avoid race between time out and tear down

On Sep 14, 2021, at 4:20 AM, Daniel Wagner [off-list ref] wrote:

From: James Smart <redacted>

To avoid race between time out and tear down, in tear down process,
first we quiesce the queue, and then delete the timer and cancel
the time out work for the queue.

This patch merges the admin and io sync ops into the queue teardown logic
as shown in the RDMA patch 3017013dcc "nvme-rdma: avoid race between time
out and tear down". There is no teardown_lock in nvme-fc.

Signed-off-by: James Smart <redacted>
CC: Chao Leng <redacted>
Tested-by: Daniel Wagner <redacted>
Reviewed-by: Daniel Wagner <redacted>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
drivers/nvme/host/fc.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index b5d9a5507de5..6ebe68396712 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c

@@ -2487,6 +2487,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)

	 */
	if (ctrl->ctrl.queue_count > 1) {
		nvme_stop_queues(&ctrl->ctrl);
+		nvme_sync_io_queues(&ctrl->ctrl);
		blk_mq_tagset_busy_iter(&ctrl->tag_set,
				nvme_fc_terminate_exchange, &ctrl->ctrl);
		blk_mq_tagset_wait_completed_request(&ctrl->tag_set);

@@ -2510,6 +2511,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues)

	 * clean up the admin queue. Same thing as above.
	 */
	blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
+	blk_sync_queue(ctrl->ctrl.admin_q);
	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
				nvme_fc_terminate_exchange, &ctrl->ctrl);
	blk_mq_tagset_wait_completed_request(&ctrl->admin_tag_set);
-- 
2.29.2