Re: [Qemu-devel] [PATCH v2] block: Introduce bs->zero_beyond_eof

[Asias He <asias@redhat.com>]

On Thu, Aug 22, 2013 at 02:12:29PM +0200, Stefan Hajnoczi wrote:
> On Thu, Aug 22, 2013 at 03:24:14PM +0800, Asias He wrote:
> > In 4146b46c42e0989cb5842e04d88ab6ccb1713a48 (block: Produce zeros when
> > protocols reading beyond end of file), we break qemu-iotests ./check
> > -qcow2 022. This happens because qcow2 temporarily sets ->growable = 1
> > for vmstate accesses (which are stored beyond the end of regular image
> > data).
> > 
> > We introduce the bs->zero_beyond_eof to allow qcow2_load_vmstate() to
> > disable ->zero_beyond_eof temporarily in addition to enable ->growable.
> > 
> > Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
> > Signed-off-by: Asias He <asias@redhat.com>
> > ---
> > Changes in v2: Set bs->zero_beyond_eof in bdrv_open_common
> > 
> >  block.c                   | 4 +++-
> >  block/qcow2.c             | 3 +++
> >  include/block/block_int.h | 3 +++
> >  3 files changed, 9 insertions(+), 1 deletion(-)
> 
> Thanks, applied to my block tree:
> https://github.com/stefanha/qemu/commits/block
> 
> ...with a little twist: since the broken patch hasn't been merged yet
> I'm applying this fix *first* to keep the tree bisectable.

Thanks!

> Stefan

-- 
Asias