Re: [PATCH RFC v3 36/41] scsi: libsas,hisi_sas,mvsas,pm8001: Allocate Scsi_cmd for slow task

[John Garry <john.garry@xxxxxxxxxx>]

On 30/04/2020 14:18, Hannes Reinecke wrote:
> k *sas_alloc_slow_task(gfp_t flags)
> +struct sas_task *sas_alloc_slow_task(struct sas_ha_struct *ha,
> +				     struct domain_device *dev,
> +				     struct scsi_lun *lun, gfp_t flags)
>   {
>   	struct sas_task *task = sas_alloc_task(flags);
> -	struct sas_task_slow *slow = kmalloc(sizeof(*slow), flags);
> +	struct Scsi_Host *shost = ha->core.shost;
> +	struct sas_task_slow *slow;
>   
> -	if (!task || !slow) {
> -		if (task)
> -			kmem_cache_free(sas_task_cache, task);
> -		kfree(slow);
> +	if (!task)
>   		return NULL;
> +
> +	slow = kzalloc(sizeof(*slow), flags);
> +	if (!slow)
> +		goto out_err_slow;
> +
> +	if (shost->nr_reserved_cmds) {
> +		struct scsi_device *sdev;
> +
> +		if (dev && dev->starget) {
> +			sdev = scsi_device_lookup_by_target(dev->starget,
> +						    scsilun_to_int(lun));
> +			if (!sdev)
> +				goto out_err_scmd;
> +		} else
> +			sdev = ha->core.shost_dev;

Could we always just use the ha->core.shost_dev? I feel that it would 
make the code neater.

Thanks,
John

> +		slow->scmd = scsi_get_reserved_cmd(sdev, DMA_NONE, false);
> +		if (!slow->scmd)
> +			goto out_err_scmd;
> +		ASSIGN_SAS_TASK(slow->scmd, task);
>   	}