[PATCH v4 1/3] block: move ref_tag calculation func to the block layer

[axboe@kernel.dk (Jens Axboe)]

On 7/28/18 4:12 PM, Max Gurtovoy wrote:
> 
> 
> On 7/27/2018 6:38 PM, Jens Axboe wrote:
>> On 7/27/18 9:21 AM, Jens Axboe wrote:
>>> On 7/25/18 9:46 AM, Max Gurtovoy wrote:
>>>> Currently this function is implemented in the scsi layer, but it's
>>>> actual place should be the block layer since T10-PI is a general
>>>> data integrity feature that is used in the nvme protocol as well.
>>>
>>> Applied 1-3 for 4.19.
>>
>> This:
>>
>> static inline u32 t10_pi_ref_tag(struct request *rq)
>> {
>>          return blk_rq_pos(rq) >>
>>                  (rq->q->integrity.interval_exp - 9) & 0xffffffff;
>> }
>>
>> won't work for !CONFIG_BLK_DEV_INTEGRITY. I didn't want to make the
>> change, but looks like it should either return -1U as we the value
>> should mean nothing if BLK_DEV_INTEGRITY isn't set, or just ignore the
>> shift and return blk_rq_pos(rq) & 0xffffffff.
>>
>> Please fixup and resend the series.
>>
> 
> will this be good enough:
> 
> diff --git a/include/linux/t10-pi.h b/include/linux/t10-pi.h
> index 81ae4c4..5a427c2 100644
> --- a/include/linux/t10-pi.h
> +++ b/include/linux/t10-pi.h
> @@ -39,8 +39,12 @@ struct t10_pi_tuple {
> 
>   static inline u32 t10_pi_ref_tag(struct request *rq)
>   {
> +#ifdef CONFIG_BLK_DEV_INTEGRITY
>          return blk_rq_pos(rq) >>
>                  (rq->q->integrity.interval_exp - 9) & 0xffffffff;
> +#else
> +       return -1U;
> +#endif
>   }

I think so, that looks fine to me.

-- 
Jens Axboe