Re: [PATCH]: Rename REQ_COPY_USER to more descriptive REQ_HAS_TAIL_SPACE_FOR_PADDING

Vladislav Bolkhovitin
2009-07-09T18:30:23Z

Jens Axboe, on 07/09/2009 10:17 PM wrote:
> On Thu, Jul 09 2009, Vladislav Bolkhovitin wrote:
>> Currently names of REQ_COPY_USER and __REQ_COPY_USER constants are confusing,
>> because they actually mean that the buffer for the corresponding requests
>> has space in the tail for padding in case of DMA padding restrictions.
>
> No, that's not what it means, the fact that there's padding room is a
> side effect of the map type. So I'd suggest adding a comment above that
> if {} in blk_rq_map_sg(), something that should have been there from the
> beginning.

Can you elaborate a bit more about what REQ_COPY_USER should mean, please?

As far as I can see from the sources, currently it's used to only to
determine if there is the padding space. Maybe, the original meaning
doesn't make sense anymore?

Thanks,
Vlad