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Message-ID: <1356c5b0-5cd7-b006-1b34-a66a34e23fb4@huawei.com>
Date:   Thu, 29 Sep 2022 08:33:29 +0100
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Subject: Re: [PATCH 1/6] scsi: libsas: Add sas_task_find_rq()
To:     Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        <jejb@linux.ibm.com>, <martin.petersen@oracle.com>,
        <jinpu.wang@cloud.ionos.com>, <damien.lemoal@wdc.com>
CC:     <hare@suse.de>, <linux-scsi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linuxarm@huawei.com>,
        <ipylypiv@google.com>, <changyuanl@google.com>, <hch@lst.de>
References: <1664368034-114991-1-git-send-email-john.garry@huawei.com>
 <1664368034-114991-2-git-send-email-john.garry@huawei.com>
 <0c0306d7-2645-874a-9745-8aa5dcfeede1@opensource.wdc.com>
From:   John Garry <john.garry@huawei.com>
In-Reply-To: <0c0306d7-2645-874a-9745-8aa5dcfeede1@opensource.wdc.com>
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Precedence: bulk

On 29/09/2022 03:09, Damien Le Moal wrote:
> On 9/28/22 21:27, 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;
> 
> I would change these 2 lines into a single line:
> 
> 		struct ata_queued_cmd *qc = task->uldd_task;
> 
> And no cast as suggested.
> 
>> +		scmd = qc->scsicmd;

So do you prefer:

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

As Jason suggested?

Thanks,
John