On Fri, Nov 10, 2017 at 10:34:59AM -0600, Eric Blake wrote: > On 11/03/2017 09:41 AM, Daniel P. Berrange wrote: > > After committing the qcow2 image contents into the base image, qemu-img > > will call bdrv_make_empty to drop the payload in the layered image. > > > > When this is done for qcow2 images, it blows away the LUKS encryption > > header, making the resulting image unusable. There are two codepaths > > for emptying a qcow2 image, and the second (slower) codepaths leaves > > the LUKS header intact, so force use of that codepath. > > > > Signed-off-by: Daniel P. Berrange <berra...@redhat.com> > > --- > > > > NB, ideally we would fix the faster codepath in make_completely_empty, but > > having looked at the code, I've really no idea how to even start on fixing > > that > > to not kill the LUKS header clusters. > > Hmm - I wonder if persistent bitmaps are also corrupted in the fast path.
I also wonder if there's anything better we can do to make us safer by default, so we default to the slow & safe path, unless we can provide we *only* have the subset of features that are safe for the fast path ? Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
