On Tue, Jun 17, 2014 at 05:53:58PM -0400, Jeff Cody wrote:
> 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>
> ---
>  blockdev.c           | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  qapi/block-core.json |  60 ++++++++++++++++++++++++++++++
>  qmp-commands.hx      |  74 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 236 insertions(+)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>