On 10.09.2015 15:39, Alberto Garcia wrote:
> If set to true, the image will be opened with the BDRV_O_NO_BACKING
> flag. This is useful for creating snapshots using images opened with
> blockdev-add, since they are not supposed to have a backing image
> before the operation.
> 
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
>  block.c              | 5 +++++
>  qapi/block-core.json | 6 +++++-
>  2 files changed, 10 insertions(+), 1 deletion(-)

Ignorant of any possible previous discussion that might have taken
place: The documentation for @backing says it may be set to the empty
string in order to achieve exactly that.

So why do we need the new flag? Because "backing: ''" is ugly?

Max