Am 17.02.2014 um 18:12 hat Eric Blake geschrieben:
> On 02/17/2014 07:45 AM, Kevin Wolf wrote:
> > Instead of making the backing file contents visible again after a discard
> > request, set the zero flag if possible (i.e. on version >= 3).
> > 
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> >  block/qcow2-cluster.c  | 22 ++++++++++++++++++++--
> >  tests/qemu-iotests/046 | 18 ++++++++++++++----
> >  2 files changed, 34 insertions(+), 6 deletions(-)
> > 
> 
> > +        if (!!(old_offset & QCOW_OFLAG_ZERO)) {
> 
> The !! is not necessary here; any non-zero value in a boolean context
> gives the same result as an explicit conversion to 0-or-1.

Thanks, that looks a bit odd indeed. I'll change it.

Kevin