Re: [Qemu-devel] [PATCH 5/5] vmdk: add bdrv_co_write_zeroes

[Fam Zheng <famz@redhat.com>]

On Fri, 04/19 11:12, Stefan Hajnoczi wrote:
> On Fri, Apr 19, 2013 at 11:48:45AM +0800, Fam Zheng wrote:
> > From: Feiran Zheng <feiran.zheng@emc.com>
> > 
> > Use special offset to write zeroes efficiently, when zeroed-grain GTE is
> > available. If zero-write an allocated cluster, cluster is leaked because
> > its offset pointer is overwritten by "0x1".
> > 
> > Signed-off-by: Fam Zheng <famz@redhat.com>
> > ---
> >  block/vmdk.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++-------------
> >  1 file changed, 50 insertions(+), 13 deletions(-)
> 
> Do existing qemu-iotests zero write tests cases cover this?  Do you need
> to add vmdk to their list of supported formats?

I guess they cover and has include vmdk already, need to double check
correctness of both side and fix the multiple extents cases
(twoGbMaxExtent{Sparse,Flat}).

This patch can't properly handle metadata update for zero write, will
fix in next version.

-- 
Fam