Re: [Qemu-devel] [PATCH 01/12] nbd: rename read_sync and friends

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

02.06.2017 16:49, Eric Blake wrote:
> On 06/02/2017 07:00 AM, Vladimir Sementsov-Ogievskiy wrote:
>
>>>>> 2. _sync suffix
>>>>>      _sync is related to the fact, that nbd_wr_syncv doesn't return if
>>>> s/fact,/fact/
>>>>
>>>>>      write to socket returns EAGAIN. In first implementation
>>>>> nbd_wr_syncv
>>>>>      just loops while getting EAGAIN, current implementation yields in
>>>>>      this case.
>>>> As mentioned in your followup, you may want to rewrite this to:
>>>>
>>>> _sync was originally used (back in commit 7a5ca864 when it was named
>>>> wr_sync) to indicate that we looped rather than returned on EAGAIN.  But
>>>> now we use qio_channel which yields on our behalf rather than giving us
>>>> EAGAIN.
>>> hmm, I like my wording (with adding note "... implementaion
>>> nbd_wr_syncv (was wr_sync in 7a5ca8648b) just ...")  more, because:
>>> 1. not only nbd_wr_syncv has that suffix, so nbd_wr_syncv should be
>>> mentioned (as we mention wr_sync)
>>> 2. I don't say about contrast between old and current, I say that they
>>> are similar.
>>>
>> Finally, are you OK with my wording? If I reroll, can I add your r-b?
> What final wording are you proposing (full paragraph, not a snippet)?

2. _sync suffix
    _sync is related to the fact that nbd_wr_syncv doesn't return if
    write to socket returns EAGAIN. In first implementation nbd_wr_syncv
    (was wr_sync in 7a5ca8648b) just loops while getting EAGAIN, current
    implementation yields in this case.
    Why to get rid of it:
    - it is normal for r/w functions to be synchronous, so having
      additional suffix for it looks redundant (contrariwise, we have
      _aio suffix for async functions)
    - _sync suffix in block layer is used when function does flush (so
      using it for other thing is confusing a bit)
    - keep function names short after adding nbd_ prefix

>
>>>> Reviewed-by: Eric Blake <eblake@redhat.com>
> At any rate, I already gave R-b for the code, so finessing the commit
> message doesn't change that if the code remains unchanged.
>

-- 
Best regards,
Vladimir