Am 18.07.2017 um 02:34 hat John Snow geschrieben: > We do not currently guarantee that QEMU will or will not open a > backing file when creating a new overlay file. Presently, QEMU will > not open that file if you provide a filesize, because it has no reason > to want to open it in that case. > > This series makes the contract more explicit: if '-u' is provided to > create, we will not open the backing image regardless, erroring out if > a size was not provided. > > In the other case, if '-u' is not provided, we now endeavor to open the > backing image if possible to check that it exists. For now, if a size > is provided and the image does not exist, QEMU will only warn to maintain > compatibility with legacy behavior. > > In the future, QEMU may treat the operation as a failure if '-u' was not > provided. > > Tests are amended primarily to pass the '-u' flag where it makes sense; > which is when creating overlays for objects already open by QEMU. These > will now generally fail to succeed because of image locking. In this > case, they only warn instead of fail, but this keeps the output cleaner. > > Test 111 is updated to accommodate a new error message. > 082, 085, 139, 156 and 158 add '-u' just to suppress warnings.
Thanks, applied to the block branch. Kevin
