Re: [PATCH RFC v3 21/22] scsi: libsas: Queue internal abort commands as requests

[John Garry <john.g.garry@oracle.com>]

On 29/10/2022 02:15, chenxiang (M) wrote:
> Hi John,
> 
> For internal abort commands, it allocates and deliver requests through 
> sdev->request_queue.
> 
> Is it possible that we still need to send internal abort commands even 
> if sdev is freed?
> 
> I  notices that in sas_destruct_devices, it calls sas_rphy_delete() to 
> remove target, and then call i->dft->lldd_dev_gone()
> 
> which will call internal abort commands.

Good question. I did not properly check the removal path and, indeed, 
the sdev would be gone when we call lldd_dev_gone -> 
internal_task_abort_dev, so that should fail to execute.

However I do wonder why we really need to call internal_task_abort_dev 
in the lldd_dev_gone callback. At the point lldd_dev_gone is called all 
IO should be complete - indeed, it is now accounted for as requests 
associated with the sdev. If it is really required to be called (HW 
requirement?) then maybe it could be relocated to sdev/starget teardown 
callback.

Thanks,
John

> 
> 
> 
> 在 2022/10/25 18:18, John Garry 写道:
>> Like what we did for SMP commands, send internal abort commands through
>> the block layer.
>>
>> At this point we can delete special handling in sas_task_abort() for SAS
>> "internal" commands, as every slow task now has a request associated.
>>
>> Function sas_task_internal_timedout() is no longer referenced, so delete
>> it.
>>
>> Signed-off-by: John Garry <john.garry@huawei.com>
>> ---
>>   drivers/scsi/hisi_sas/hisi_sas_main.c | 36 +++++++++----------
>>   drivers/scsi/libsas/sas_expander.c    |  2 +-
>>   drivers/scsi/libsas/sas_init.c        | 12 +++++--
>>   drivers/scsi/libsas/sas_internal.h    |  3 +-
>>   drivers/scsi/libsas/sas_scsi_host.c   | 52 ++++++---------------------
>>   include/scsi/libsas.h                 |  1 -
>>   6 files changed, 38 insertions(+), 68 deletions(-)
>>
>> diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c 
>> b/drivers/scsi/hisi_sas/hisi_sas_main.c
>> index fe2752d24fe8..65475775c844 100644
>> --- a/drivers/scsi/hisi_sas/hisi_sas_main.c
>> +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
>> @@ -465,7 +465,7 @@ static int hisi_sas_queue_command(struct sas_task 
>> *task, gfp_t gfp_flags)
>>       struct hisi_sas_port *port;
>>       struct hisi_hba *hisi_hba;
>>       struct hisi_sas_slot *slot;
>> -    struct request *rq = NULL;
>> +    struct request *rq;
>>       struct device *dev;
>>       int rc;
>> @@ -485,6 +485,21 @@ static int hisi_sas_queue_command(struct sas_task 
>> *task, gfp_t gfp_flags)
>>       hisi_hba = dev_to_hisi_hba(device);
>>       dev = hisi_hba->dev;
>> +    rq = sas_task_find_rq(task);
>> +    if (rq) {
>> +        unsigned int dq_index;
>> +        u32 blk_tag;
>> +
>> +        blk_tag = blk_mq_unique_tag(rq);
>> +        dq_index = blk_mq_unique_tag_to_hwq(blk_tag);
>> +        dq = &hisi_hba->dq[dq_index];
>> +    } else {
>> +        struct Scsi_Host *shost = hisi_hba->shost;
>> +        struct blk_mq_queue_map *qmap = 
>> &shost->tag_set.map[HCTX_TYPE_DEFAULT];
>> +        int queue = qmap->mq_map[raw_smp_processor_id()];
>> +
>> +        dq = &hisi_hba->dq[queue];
>> +    }
>>       switch (task->task_proto) {
>>       case SAS_PROTOCOL_SSP:
>> @@ -519,22 +534,6 @@ static int hisi_sas_queue_command(struct sas_task 
>> *task, gfp_t gfp_flags)
>>                   return -ECOMM;
>>           }
>> -
>> -        rq = sas_task_find_rq(task);
>> -        if (rq) {
>> -            unsigned int dq_index;
>> -            u32 blk_tag;
>> -
>> -            blk_tag = blk_mq_unique_tag(rq);
>> -            dq_index = blk_mq_unique_tag_to_hwq(blk_tag);
>> -            dq = &hisi_hba->dq[dq_index];
>> -        } else {
>> -            struct Scsi_Host *shost = hisi_hba->shost;
>> -            struct blk_mq_queue_map *qmap = 
>> &shost->tag_set.map[HCTX_TYPE_DEFAULT];
>> -            int queue = qmap->mq_map[raw_smp_processor_id()];
>> -
>> -            dq = &hisi_hba->dq[queue];
>> -        }
>>           break;
>>       case SAS_PROTOCOL_INTERNAL_ABORT:
>>           if (!hisi_hba->hw->prep_abort)
>> @@ -543,13 +542,10 @@ static int hisi_sas_queue_command(struct 
>> sas_task *task, gfp_t gfp_flags)
>>           if (test_bit(HISI_SAS_HW_FAULT_BIT, &hisi_hba->flags))
>>               return -EIO;
>> -        hisi_hba = dev_to_hisi_hba(device);
>> -
>>           if (unlikely(test_bit(HISI_SAS_REJECT_CMD_BIT, 
>> &hisi_hba->flags)))
>>               return -EINVAL;
>>           port = to_hisi_sas_port(sas_port);
>> -        dq = &hisi_hba->dq[task->abort_task.qid];
>>           break;
>>       default:
>>           dev_err(hisi_hba->dev, "task prep: unknown/unsupported proto 
>> (0x%x)\n",
>> diff --git a/drivers/scsi/libsas/sas_expander.c 
>> b/drivers/scsi/libsas/sas_expander.c
>> index cc41127ea5cc..e852f1565fe7 100644
>> --- a/drivers/scsi/libsas/sas_expander.c
>> +++ b/drivers/scsi/libsas/sas_expander.c
>> @@ -50,7 +50,7 @@ static int smp_execute_task_sg(struct domain_device 
>> *dev,
>>               break;
>>           }
>> -        task = sas_alloc_slow_task_rq(dev, GFP_KERNEL);
>> +        task = sas_alloc_slow_task_rq(dev, GFP_KERNEL, -1U);
>>           if (!task) {
>>               res = -ENOMEM;
>>               break;
>> diff --git a/drivers/scsi/libsas/sas_init.c 
>> b/drivers/scsi/libsas/sas_init.c
>> index 5f9e71a54799..c3f602bd2c4c 100644
>> --- a/drivers/scsi/libsas/sas_init.c
>> +++ b/drivers/scsi/libsas/sas_init.c
>> @@ -56,7 +56,7 @@ struct sas_task *sas_alloc_slow_task(gfp_t flags)
>>       return task;
>>   }
>> -struct sas_task *sas_alloc_slow_task_rq(struct domain_device *device, 
>> gfp_t flags)
>> +struct sas_task *sas_alloc_slow_task_rq(struct domain_device *device, 
>> gfp_t flags, unsigned int qid)
>>   {
>>       struct sas_ha_struct *sas_ha = device->port->ha;
>>       struct Scsi_Host *shost = sas_ha->core.shost;
>> @@ -86,8 +86,14 @@ struct sas_task *sas_alloc_slow_task_rq(struct 
>> domain_device *device, gfp_t flag
>>       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);
>> +    if (qid == -1U) {
>> +        rq = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN,
>> +                    BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT);
>> +    } else {
>> +        rq = scsi_alloc_request_hwq(sdev->request_queue, REQ_OP_DRV_IN,
>> +                    BLK_MQ_REQ_RESERVED | BLK_MQ_REQ_NOWAIT,
>> +                    qid);
>> +    }
>>       if (IS_ERR(rq)) {
>>           sas_free_task(task);
>>           return NULL;
>> diff --git a/drivers/scsi/libsas/sas_internal.h 
>> b/drivers/scsi/libsas/sas_internal.h
>> index 9b58948c57c2..af4a4bf88830 100644
>> --- a/drivers/scsi/libsas/sas_internal.h
>> +++ b/drivers/scsi/libsas/sas_internal.h
>> @@ -54,7 +54,8 @@ void sas_free_event(struct asd_sas_event *event);
>>   struct sas_task *sas_alloc_task(gfp_t flags);
>>   struct sas_task *sas_alloc_slow_task(gfp_t flags);
>> -struct sas_task *sas_alloc_slow_task_rq(struct domain_device *device, 
>> gfp_t flags);
>> +struct sas_task *sas_alloc_slow_task_rq(struct domain_device *device, 
>> gfp_t flags,
>> +                      unsigned int qid);
>>   void sas_free_task(struct sas_task *task);
>>   int  sas_register_ports(struct sas_ha_struct *sas_ha);
>> diff --git a/drivers/scsi/libsas/sas_scsi_host.c 
>> b/drivers/scsi/libsas/sas_scsi_host.c
>> index e6ee8dd56a45..a93e019a7dbf 100644
>> --- a/drivers/scsi/libsas/sas_scsi_host.c
>> +++ b/drivers/scsi/libsas/sas_scsi_host.c
>> @@ -920,23 +920,6 @@ void sas_task_complete_internal(struct sas_task 
>> *task)
>>       scsi_done(scmd);
>>   }
>> -void sas_task_internal_timedout(struct timer_list *t)
>> -{
>> -    struct sas_task_slow *slow = from_timer(slow, t, timer);
>> -    struct sas_task *task = slow->task;
>> -    bool is_completed = true;
>> -    unsigned long flags;
>> -
>> -    spin_lock_irqsave(&task->task_state_lock, flags);
>> -    if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
>> -        task->task_state_flags |= SAS_TASK_STATE_ABORTED;
>> -        is_completed = false;
>> -    }
>> -    spin_unlock_irqrestore(&task->task_state_lock, flags);
>> -
>> -    if (!is_completed)
>> -        complete(&task->slow_task->completion);
>> -}
>>   enum blk_eh_timer_return sas_internal_timeout(struct scsi_cmnd *scmd)
>>   {
>>       struct sas_task *task = TO_SAS_TASK(scmd);
>> @@ -978,28 +961,23 @@ static int sas_execute_internal_abort(struct 
>> domain_device *device,
>>       int res, retry;
>>       for (retry = 0; retry < TASK_RETRY; retry++) {
>> -        task = sas_alloc_slow_task(GFP_KERNEL);
>> +        struct request *rq;
>> +
>> +        task = sas_alloc_slow_task_rq(device, GFP_KERNEL, qid);
>>           if (!task)
>>               return -ENOMEM;
>>           task->dev = device;
>>           task->task_proto = SAS_PROTOCOL_INTERNAL_ABORT;
>> -        task->task_done = sas_task_internal_done;
>> -        task->slow_task->timer.function = sas_task_internal_timedout;
>> -        task->slow_task->timer.expires = jiffies + TASK_TIMEOUT;
>> -        add_timer(&task->slow_task->timer);
>> +        task->task_done = sas_task_complete_internal;
>>           task->abort_task.tag = tag;
>>           task->abort_task.type = type;
>> -        task->abort_task.qid = qid;
>> -        res = i->dft->lldd_execute_task(task, GFP_KERNEL);
>> -        if (res) {
>> -            del_timer_sync(&task->slow_task->timer);
>> -            pr_err("Executing internal abort failed %016llx (%d)\n",
>> -                   SAS_ADDR(device->sas_addr), res);
>> -            break;
>> -        }
>> +        rq = scsi_cmd_to_rq(task->uldd_task);
>> +        rq->timeout = TASK_TIMEOUT;
>> +
>> +        blk_execute_rq_nowait(rq, true);
>>           wait_for_completion(&task->slow_task->completion);
>>           res = TMF_RESP_FUNC_FAILED;
>> @@ -1069,7 +1047,7 @@ int sas_execute_tmf(struct domain_device 
>> *device, void *parameter,
>>       for (retry = 0; retry < TASK_RETRY; retry++) {
>>           struct request *rq;
>> -        task = sas_alloc_slow_task_rq(device, GFP_KERNEL);
>> +        task = sas_alloc_slow_task_rq(device, GFP_KERNEL, -1U);
>>           if (!task)
>>               return -ENOMEM;
>> @@ -1251,17 +1229,7 @@ void sas_task_abort(struct sas_task *task)
>>   {
>>       struct scsi_cmnd *sc = task->uldd_task;
>> -    /* Escape for libsas internal commands */
>> -    if (!sc) {
>> -        struct sas_task_slow *slow = task->slow_task;
>> -
>> -        if (!slow)
>> -            return;
>> -        if (!del_timer(&slow->timer))
>> -            return;
>> -        slow->timer.function(&slow->timer);
>> -        return;
>> -    }
>> +    WARN_ON_ONCE(!sc);
>>       if (dev_is_sata(task->dev) && !task->slow_task)
>>           sas_ata_task_abort(task);
>> diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
>> index f02156ccd376..60543d8b01d4 100644
>> --- a/include/scsi/libsas.h
>> +++ b/include/scsi/libsas.h
>> @@ -565,7 +565,6 @@ enum sas_internal_abort {
>>   struct sas_internal_abort_task {
>>       enum sas_internal_abort type;
>> -    unsigned int qid;
>>       u16 tag;
>>   };
> 
> 
>