Re: [PATCH 05/17] bio: cleanup rw usage

[Boaz Harrosh <bharrosh@panasas.com>]

On 04/02/2009 12:02 PM, Tejun Heo wrote:
> Boaz Harrosh wrote:
>> On 04/01/2009 04:44 PM, Tejun Heo wrote:
>>> Impact: cleanup
>>>
>>> bio confusingly uses @write_to_vm and @reading for data directions,
>>> both of which mean the opposite of the usual block/bio convention of
>>> using READ and WRITE w.r.t. IO devices.  The only place where the
>>> inversion is necessary is when caling get_user_pages_fast() in
>>> bio_copy_user_iov() as the gup uses the VM convention of read/write
>>> w.r.t. VM.
>>>
>>> This patch converts all bio functions to use READ/WRITE rw parameter
>>> and let the one place where inversion is necessary to rw == READ.
>>>
>> Hi one more nit picking just if you are at it. If you want
>> I can do the work and send it to you so you can squash it into this patch.
>> See bellow
>>
>>> +	if (rw == WRITE)
>>> +		bio->bi_rw |= 1 << BIO_RW;
>> can we pleas have an inline that does that? Like bio_set_dir()?
>> and change all users. You will be surprised how many there are.
>>
>> It gives me an hart attack every time I have to write yet another
>> one.
> 
> Things like this are actually what I'm trying to clean up.  If you
> look at the whole series, at the end, there remains only one place
> which sets the flag in the blk/bio map paths and all users of
> blk_rq_map_*() interface couldn't care less about the flag because
> they provide only the necessary information through strictly defined
> API.
> 

Right, I know. and its great.

I'm saying, all these other block-layer places and all
these places above block like stacking drivers and filesystems
That use generic_make_request and friends. If at it these can be
cleaned as well, in regard to this small thingy.

> Thanks.
> 

I'll do it, no problems. Would you push it with your patchset?

Thanks
Boaz