On Wed 29 Aug 2018 11:44:52 AM CEST, Max Reitz wrote:
> On 2018-08-28 15:26, Alberto Garcia wrote:
>> On Thu 09 Aug 2018 11:35:02 PM CEST, Max Reitz wrote:
>>> + backing_overridden = bdrv_backing_overridden(bs);
>>> +
>>> + if (bs->open_flags & BDRV_O_NO_IO) {
>>> + /* Without I/O, the backing file does not change anything.
>>> + * Therefore, in such a case (primarily qemu-img), we can
>>> + * pretend the backing file has not been overridden even if
>>> + * it technically has been. */
>>> + backing_overridden = false;
>>> + }
>>
>> What is this for?
>
> qemu-img info opens files with BDRV_O_NO_BACKING. Without this check,
> you'd get a json:{} filename with "backing": null.
Ah, I see.
Reviewed-by: Alberto Garcia <[email protected]>
Berto
