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

[Vladimir Sementsov-Ogievskiy]

01.06.2017 11:03, Sementsov-Ogievskiy Vladimir wrote:
> On 31.05.2017 21:46, Eric Blake wrote:
> > On 05/31/2017 11:55 AM, Vladimir Sementsov-Ogievskiy wrote:
> > > Rename
> > >    nbd_wr_syncv -> nbd_rwv
> > >    read_sync -> nbd_read
> > >    read_sync_eof -> nbd_read_eof
> > >    write_sync -> nbd_write
> > >    drop_sync -> nbd_drop
> > >
> > > 1. nbd_ prefix
> > >     read_sync and write_sync are already shared, so it is good to 
> > > have a
> > >     namespace prefix. drop_sync will be shared, and read_sync_eof is
> > >     related to read_sync, so let's rename them all.
> > >
> > > 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?

> > >     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
> > >
> > > 3. for nbd_wr_syncv let's use more common notation 'rw'
> > >
> > > Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> > > ---
> > The maintainer may be willing to tweak the commit message without
> > needing a v2.
>
> I hope for it)
>
> > > +++ b/nbd/nbd-internal.h
> > > @@ -94,14 +94,14 @@
> > >   #define NBD_ENOSPC     28
> > >   #define NBD_ESHUTDOWN  108
> > >   -/* read_sync_eof
> > > +/* nbd_read_eof
> > >    * Tries to read @size bytes from @ioc. Returns number of bytes 
> > > actually read.
> > >    * May return a value >= 0 and < size only on EOF, i.e. when 
> > > iteratively called
> > > - * qio_channel_readv() returns 0. So, there are no needs to call 
> > > read_sync_eof
> > > + * qio_channel_readv() returns 0. So, there are no needs to call 
> > > nbd_read_eof
> > As long as you are touching this:
> >
> > s/are no needs/is no need/
> >
> > Reviewed-by: Eric Blake <address@hidden>

--
Best regards,
Vladimir