Re: [Qemu-devel] [PATCH v7 for 2.1 4/4] block: add QAPI command to allow live backing file change

[Kevin Wolf <kwolf@redhat.com>]

Am 25.06.2014 um 21:40 hat Jeff Cody geschrieben:
> This allows a user to make a live change to the backing file recorded in
> an open image.
> 
> The image file to modify can be specified 2 ways:
> 
> 1) image filename
> 2) image node-name
> 
> Note: this does not cause the backing file itself to be reopened; it
> merely changes the backing filename in the image file structure, and
> in internal BDS structures.
> 
> It is the responsibility of the user to pass a filename string that
> can be resolved when the image chain is reopened, and the filename
> string is not validated.
> 
> A good analogy for this command is that it is a live version of
> 'qemu-img rebase -u', with respect to changing the backing file string.
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Signed-off-by: Jeff Cody <jcody@redhat.com>

I'm not a huge fan of adding two different addressing modes to a new QMP
command. I consider using device_name/filename as deprecated and expect
that management tools use node-name for new commands.

Also there's still Eric's reply and Jeff's promise to update the patch
once blockers were sorted out for 2.1.

I'm leaning towards declaring this patch not ready.

Kevin