Re: [PATCH v2 05/20] scsi: core: Add support for internal commands

Bart Van Assche
2021-11-22T19:04:58Z

On 11/22/21 9:46 AM, Bart Van Assche wrote:
> On 11/22/21 12:58 AM, John Garry wrote:
>> On 19/11/2021 19:57, Bart Van Assche wrote:
>>> +{
>>> +    unsigned int opf = REQ_INTERNAL;
>>> +    struct request *rq;
>>> +
>>> +    opf |= data_direction == DMA_TO_DEVICE ? REQ_OP_DRV_OUT :
>>> REQ_OP_DRV_IN;
>>> +    rq = blk_mq_alloc_request(q, opf, flags);
>>> +    if (IS_ERR(rq))
>>> +        return ERR_CAST(rq);
>>
>> I think that Christoph suggested elsewhere that we should poison all
>> the scsi_cmnd
>
> I had overlooked that comment. I will look into this.

If anyone comes up with a good approach for poisoning the scsi_cmnd I
will look into this. Only overwriting struct scsi_cmnd is not acceptable
since that would result in a memory leak. See also the memory allocation
statements in scsi_mq_init_request().

Thanks,

Bart.