Re: [PATCH RFC v3 18/22] scsi: libsas: Queue SMP commands as requests

Damien Le Moal
2022-10-27T01:36:59Z

On 10/25/22 19:18, John Garry wrote:
> Send SMP commands through the block layer so that each command gets a
> unique tag associated.
>
> Function sas_task_complete_internal() is what the LLDD calls to signal
> that the CQ is complete and this calls into the SCSI midlayer. And then
> sas_blk_end_sync_rq() is called when the request completes.
>
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
> drivers/scsi/libsas/sas_expander.c | 23 ++++++++---------------
> drivers/scsi/libsas/sas_init.c | 3 +++
> drivers/scsi/libsas/sas_internal.h | 3 +++
> drivers/scsi/libsas/sas_scsi_host.c | 16 ++++++++++++++++
> 4 files changed, 30 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
> index e7cb95683522..cc41127ea5cc 100644
> --- a/drivers/scsi/libsas/sas_expander.c
> +++ b/drivers/scsi/libsas/sas_expander.c
> @@ -43,34 +43,27 @@ static int smp_execute_task_sg(struct domain_device *dev,
> pm_runtime_get_sync(ha->dev);
> mutex_lock(&dev->ex_dev.cmd_mutex);
> for (retry = 0; retry < 3; retry++) {
> + struct request *rq;
> +
> if (test_bit(SAS_DEV_GONE, &dev->state)) {
> res = -ECOMM;
> break;
> }
>
> - task = sas_alloc_slow_task(GFP_KERNEL);
> + task = sas_alloc_slow_task_rq(dev, GFP_KERNEL);
> if (!task) {
> res = -ENOMEM;
> break;
> }
> - task->dev = dev;
> +
> + rq = scsi_cmd_to_rq(task->uldd_task);
> + rq->timeout = SMP_TIMEOUT*HZ;

Missing spaces around "*"

> +
> task->task_proto = dev->tproto;
> task->smp_task.smp_req = *req;
> task->smp_task.smp_resp = *resp;
>
> - task->task_done = sas_task_internal_done;
> -
> - task->slow_task->timer.function = sas_task_internal_timedout;
> - task->slow_task->timer.expires = jiffies + SMP_TIMEOUT*HZ;
> - add_timer(&task->slow_task->timer);
> -
> - res = i->dft->lldd_execute_task(task, GFP_KERNEL);
> -
> - if (res) {
> - del_timer_sync(&task->slow_task->timer);
> - pr_notice("executing SMP task failed:%d\n", res);
> - break;
> - }
> + blk_execute_rq_nowait(rq, true);
>
> wait_for_completion(&task->slow_task->completion);
> res = -ECOMM;
> diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
> index 90e63ff5e966..5f9e71a54799 100644
> --- a/drivers/scsi/libsas/sas_init.c
> +++ b/drivers/scsi/libsas/sas_init.c
> @@ -84,6 +84,7 @@ struct sas_task *sas_alloc_slow_task_rq(struct domain_device *device, gfp_t flag
> return NULL;
>
> task->dev = device;
> + task->task_done = sas_task_complete_internal;
>
> rq = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN,
> BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
> @@ -95,6 +96,8 @@ struct sas_task *sas_alloc_slow_task_rq(struct domain_device *device, gfp_t flag
> scmd = blk_mq_rq_to_pdu(rq);
>
> task->uldd_task = scmd;
> +
> + rq->end_io = sas_blk_end_sync_rq;
> rq->end_io_data = task;
>
> return task;
> diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
> index f5ae4de382f7..9b58948c57c2 100644
> --- a/drivers/scsi/libsas/sas_internal.h
> +++ b/drivers/scsi/libsas/sas_internal.h
> @@ -104,6 +104,9 @@ int sas_execute_tmf(struct domain_device *device, void *parameter,
> int para_len, int force_phy_id,
> struct sas_tmf_task *tmf);
>
> +void sas_task_complete_internal(struct sas_task *task);
> +enum rq_end_io_ret sas_blk_end_sync_rq(struct request *rq, blk_status_t error);
> +
> #ifdef CONFIG_SCSI_SAS_HOST_SMP
> extern void sas_smp_host_handler(struct bsg_job *job, struct Scsi_Host *shost);
> #else
> diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
> index b7d1994a8f1b..2c734a87bb7c 100644
> --- a/drivers/scsi/libsas/sas_scsi_host.c
> +++ b/drivers/scsi/libsas/sas_scsi_host.c
> @@ -913,6 +913,13 @@ void sas_task_internal_done(struct sas_task *task)
> complete(&task->slow_task->completion);
> }
>
> +void sas_task_complete_internal(struct sas_task *task)
> +{
> + struct scsi_cmnd *scmd = task->uldd_task;
> +
> + scsi_done(scmd);
> +}
> +
> void sas_task_internal_timedout(struct timer_list *t)
> {
> struct sas_task_slow *slow = from_timer(slow, t, timer);
> @@ -952,6 +959,15 @@ EXPORT_SYMBOL_GPL(sas_internal_timeout);
> #define TASK_TIMEOUT (20 * HZ)
> #define TASK_RETRY 3
>
> +enum rq_end_io_ret sas_blk_end_sync_rq(struct request *rq, blk_status_t error)
> +{
> + struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
> + struct sas_task *task = TO_SAS_TASK(scmd);
> + complete(&task->slow_task->completion);
> +
> + return RQ_END_IO_NONE;
> +}
> +
> static int sas_execute_internal_abort(struct domain_device *device,
> enum sas_internal_abort type, u16 tag,
> unsigned int qid, void *data)

--
Damien Le Moal
Western Digital Research