Re: [Qemu-devel] [PATCH v3 00/12] block/json: Add JSON protocol driver

[Stefan Hajnoczi]

On Tue, May 06, 2014 at 07:51:10PM +0200, Max Reitz wrote:
> On 06.05.2014 10:10, Stefan Hajnoczi wrote:
> >On Mon, May 05, 2014 at 06:19:07PM +0200, Max Reitz wrote:
> >>On 10.04.2014 20:43, Max Reitz wrote:
> >>>This series adds a passthrough JSON protocol block driver. Its filenames
> >>>are JSON objects prefixed by "json:". The objects are used as options
> >>>for opening another block device which will be the child of the JSON
> >>>device. Regarding this child device, the JSON driver behaves nearly the
> >>>same as raw_bsd in that it is just a passthrough driver. The only
> >>>difference is probably that the JSON driver identifies itself as a block
> >>>filter, in contrast to raw_bsd.
> >>>
> >>>The purpose of this driver is that it may sometimes be desirable to
> >>>specify options for a block device where only a filename can be given,
> >>>e.g., for backing files. Using this should obviously be the exception,
> >>>but it is nice to have if actually needed.
> >>Ping – I do understand that Kevin has reservations against this
> >>series, but as long as he doesn't explicitly ask me to reimplement
> >>this in bdrv_open() without an own block driver (which I'd more or
> >>less gladly do), I do not see issues why this series should not be
> >>merged.
> >I haven't reviewed it further because it seems like a kludge (that we
> >have to keep supporting once it's merged).  Was hoping you and Kevin
> >will come up with a long-term fix instead.
> 
> Okay, if you think the same, I guess I'll have to rewrite this
> series. I agree that including this functionality in bdrv_open() is
> the nicer alternative from the user's point of view, whereas I think
> using a separate block driver results in nicer code.
> 
> I'll rewrite this series and then we'll see how bad it actually looks. ;-)

Thanks!

Stefan