Re: [Qemu-devel] [PATCH 1/2] block: gluster - code movements, state storage changes

[Kevin Wolf <kwolf@redhat.com>]

Am 14.02.2014 um 15:41 hat Jeff Cody geschrieben:
> On Fri, Feb 14, 2014 at 03:21:28PM +0100, Stefan Hajnoczi wrote:
> > On Tue, Feb 04, 2014 at 02:26:58PM -0500, Jeff Cody wrote:
> > > @@ -291,23 +311,17 @@ static int qemu_gluster_open(BlockDriverState *bs,  QDict *options,
> > >  
> > >      filename = qemu_opt_get(opts, "filename");
> > >  
> > > +    s->filename = g_strdup(filename);
> > 
> > It's not obvious to me that copying the filename is necessary.
> > block/raw-posix.c does this:
> > 
> >   raw_s->fd = qemu_open(state->bs->filename, raw_s->open_flags);
> > 
> > Why didn't you use bs->filename?
> 
> Back when the raw-posix reopen was implemented, the .bdrv_file_open
> used the char * filename instead of options parameters.  Now that the
> filename is explicitly parsed via the options, I thought it made
> logical sense to cache the filename into the protocol state variable,
> for later use by reopen.
> 
> That way if the bs->filename was changed in some manner, the protocol
> would have the variable as originally intended to be passed to the
> .bdrv_file_open() method.
> 
> In reality, I should be able to just use bs->filename instead, as it
> does not get modified; this just seemed to make a bit more sense.

FWIW, I think we want bs->filename to go away eventually and get it
replaced by a callback (or perhaps two, a short summary one for humans
and a complete one) so that the callers work with setups that are driven
by options and don't have a filename.

Kevin