Re: [PATCH v2 4/4] scsi: set shost as hctx driver_data

[John Garry <john.garry@xxxxxxxxxx>]

On 03/12/2020 03:41, Kashyap Desai wrote:
> hctx->driver_data is not set for SCSI currently.
> Separately set hctx->driver_data = shost.

nit: this looks ok to me, but I would have made as an earlier patch so 
that you don't add code and then remove it:

>   static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx)
>   {
> -	struct request_queue *q = hctx->queue;
> -	struct scsi_device *sdev = q->queuedata;
> -	struct Scsi_Host *shost = sdev->host;

Thanks,
John

> Suggested-by: John Garry <john.garry@xxxxxxxxxx>
> Signed-off-by: Kashyap Desai <kashyap.desai@xxxxxxxxxxxx>
> ---
>   drivers/scsi/scsi_lib.c | 19 +++++++++++++------
>   1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 8675900ccc27..892315c21b70 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1789,9 +1789,7 @@ static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq,
>   
>   static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx)
>   {
> -	struct request_queue *q = hctx->queue;
> -	struct scsi_device *sdev = q->queuedata;
> -	struct Scsi_Host *shost = sdev->host;
> +	struct Scsi_Host *shost = hctx->driver_data;
>   
>   	if (shost->hostt->mq_poll)
>   		return shost->hostt->mq_poll(shost, hctx->queue_num);
> @@ -1799,6 +1797,15 @@ static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx)
>   	return 0;
>   }
>   
> +static int scsi_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
> +			  unsigned int hctx_idx)
> +{
> +	struct Scsi_Host *shost = data;
> +
> +	hctx->driver_data = shost;
> +	return 0;
> +}
> +
>   static int scsi_map_queues(struct blk_mq_tag_set *set)
>   {
>   	struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set);
> @@ -1866,15 +1873,14 @@ static const struct blk_mq_ops scsi_mq_ops_no_commit = {
>   	.cleanup_rq	= scsi_cleanup_rq,
>   	.busy		= scsi_mq_lld_busy,
>   	.map_queues	= scsi_map_queues,
> +	.init_hctx	= scsi_init_hctx,
>   	.poll		= scsi_mq_poll,
>   };
>   
>   
>   static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx)
>   {
> -	struct request_queue *q = hctx->queue;
> -	struct scsi_device *sdev = q->queuedata;
> -	struct Scsi_Host *shost = sdev->host;
> +	struct Scsi_Host *shost = hctx->driver_data;
>   
>   	shost->hostt->commit_rqs(shost, hctx->queue_num);
>   }
> @@ -1895,6 +1901,7 @@ static const struct blk_mq_ops scsi_mq_ops = {
>   	.cleanup_rq	= scsi_cleanup_rq,
>   	.busy		= scsi_mq_lld_busy,
>   	.map_queues	= scsi_map_queues,
> +	.init_hctx	= scsi_init_hctx,
>   	.poll		= scsi_mq_poll,
>   };
>