Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <99efb876-69b1-eb7c-dfa6-8ac621a25438@huawei.com>
Date:   Wed, 28 Sep 2022 14:56:24 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.6.1
Subject: Re: [PATCH 1/6] scsi: libsas: Add sas_task_find_rq()
To:     Johannes Thumshirn <Johannes.Thumshirn@wdc.com>,
        "jejb@linux.ibm.com" <jejb@linux.ibm.com>,
        "martin.petersen@oracle.com" <martin.petersen@oracle.com>,
        "jinpu.wang@cloud.ionos.com" <jinpu.wang@cloud.ionos.com>,
        Damien Le Moal <Damien.LeMoal@wdc.com>
CC:     "hare@suse.de" <hare@suse.de>,
        "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linuxarm@huawei.com" <linuxarm@huawei.com>,
        "ipylypiv@google.com" <ipylypiv@google.com>,
        "changyuanl@google.com" <changyuanl@google.com>,
        "hch@lst.de" <hch@lst.de>
References: <1664368034-114991-1-git-send-email-john.garry@huawei.com>
 <1664368034-114991-2-git-send-email-john.garry@huawei.com>
 <PH0PR04MB74164CE477846FFDB843D5419B549@PH0PR04MB7416.namprd04.prod.outlook.com>
From:   John Garry <john.garry@huawei.com>
In-Reply-To: <PH0PR04MB74164CE477846FFDB843D5419B549@PH0PR04MB7416.namprd04.prod.outlook.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 28/09/2022 14:17, Johannes Thumshirn wrote:
>> +static inline struct request *sas_task_find_rq(struct sas_task *task)
>> +{
>> +	struct scsi_cmnd *scmd;
>> +
>> +	if (!task || !task->uldd_task)
>> +		return NULL;
> Is anyone actually calling sas_task_find_rq with a NULL task?

Yeah, unfortunately. An example - the only one I think - is in the 
pm8001 driver: pm8001_ccb_alloc() function which takes a task pointer 
which may be NULL, and this function calls sas_task_find_rq()

> That doesn't make a lot of sense from an API POV for me, having
> the only argument allowed to be NULL (and not being a *free()
> kind of function).

I suppose that I could change to only call sas_task_find_rq() for 
non-NULL sas_task pointers (and remove the task check).

Thanks,
John