Re: [PATCH 1/6] scsi: libsas: Add sas_task_find_rq()

[Jason Yan <yanaijie@huawei.com>]

On 2022/9/28 20:27, John Garry wrote:
> blk-mq already provides a unique tag per request. Some libsas LLDDs - like
> hisi_sas - already use this tag as the unique per-IO HW tag.
> 
> Add a common function to provide the request associated with a sas_task
> for all libsas LLDDs.
> 
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
>   include/scsi/libsas.h | 22 ++++++++++++++++++++++
>   1 file changed, 22 insertions(+)
> 
> diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
> index f86b56bf7833..bc51756a3317 100644
> --- a/include/scsi/libsas.h
> +++ b/include/scsi/libsas.h
> @@ -644,6 +644,28 @@ static inline bool sas_is_internal_abort(struct sas_task *task)
>   	return task->task_proto == SAS_PROTOCOL_INTERNAL_ABORT;
>   }
>   
> +static inline struct request *sas_task_find_rq(struct sas_task *task)
> +{
> +	struct scsi_cmnd *scmd;
> +
> +	if (!task || !task->uldd_task)
> +		return NULL;
> +
> +	if (task->task_proto & SAS_PROTOCOL_STP_ALL) {
> +		struct ata_queued_cmd *qc;
> +
> +		qc = task->uldd_task;
> +		scmd = qc->scsicmd;

Can we remove that local qc?

and
	scmd = ((struct ata_queued_cmd *)task->uldd_task)->scsicmd;

Thanks,
Jason

> +	} else {
> +		scmd = task->uldd_task;
> +	}
> +
> +	if (!scmd)
> +		return NULL;
> +
> +	return scsi_cmd_to_rq(scmd);
> +}
> +
>   struct sas_domain_function_template {
>   	/* The class calls these to notify the LLDD of an event. */
>   	void (*lldd_port_formed)(struct asd_sas_phy *);
>