2021-07-20 12:46:44

by Daniel Wagner

Subject: [PATCH v3 5/6] nvme-fc: avoid race between time out and tear down

From: James Smart <[email protected]>

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 <[email protected]>
CC: Chao Leng <[email protected]>
Tested-by: Daniel Wagner <[email protected]>
[dwagner: updated commit id referenced in commit message]
Reviewed-by: Daniel Wagner <[email protected]>
---
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 a64be4fb07af..112e62cd8a2a 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

2021-07-20 17:59:25

by Hannes Reinecke

Subject: Re: [PATCH v3 5/6] nvme-fc: avoid race between time out and tear down

On 7/20/21 2:43 PM, Daniel Wagner wrote:
> From: James Smart <[email protected]>
>
> 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 <[email protected]>
> CC: Chao Leng <[email protected]>
> Tested-by: Daniel Wagner <[email protected]>
> [dwagner: updated commit id referenced in commit message]
> Reviewed-by: Daniel Wagner <[email protected]>
> ---
> drivers/nvme/host/fc.c | 2 ++
> 1 file changed, 2 insertions(+)
>
Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
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