Re: [PATCH v2 4/5] nvme-fc: Wait with a timeout for queue to freeze

[Hannes Reinecke]

On 7/8/21 11:27 AM, Daniel Wagner wrote:
> Do not wait indifinitly for all queues to freeze. Instead use a
> timeout and abort the operation if we get stuck.
>
> Reviewed-by: James Smart <jsmart2021@xxxxxxxxx>
> Signed-off-by: Daniel Wagner <dwagner@xxxxxxx>
> ---
>   drivers/nvme/host/fc.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index d0eb81387d4e..8e1fc3796735 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -2956,7 +2956,14 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl)
>   		dev_info(ctrl->ctrl.device,
>   			"reconnect: revising io queue count from %d to %d\n",
>   			prior_ioq_cnt, nr_io_queues);
> -		nvme_wait_freeze(&ctrl->ctrl);
> +		if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) {
> +			/*
> +			 * If we timed out waiting for freeze we are likely to
> +			 * be stuck.  Fail the controller initialization just
> +			 * to be safe.
> +			 */
> +			return -ENODEV;

For controller reset we're using '-ENOTCONN'; maybe it's worthwhile to 
use the same error code here.
But that's just a minor detail.

> +		}
>   		blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues);
>   		nvme_unfreeze(&ctrl->ctrl);
>   	}
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke                Kernel Storage Architect
hare@xxxxxxx                              +49 911 74053 688
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