From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:38833)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1VZGvT-0001Ft-3d
	for qemu-devel@nongnu.org; Thu, 24 Oct 2013 05:10:00 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1VZGvN-0002mf-HN
	for qemu-devel@nongnu.org; Thu, 24 Oct 2013 05:09:55 -0400
Received: from mail-wi0-x22a.google.com ([2a00:1450:400c:c05::22a]:62623)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <paolo.bonzini@gmail.com>) id 1VZGvN-0002ma-AT
	for qemu-devel@nongnu.org; Thu, 24 Oct 2013 05:09:49 -0400
Received: by mail-wi0-f170.google.com with SMTP id l12so9525082wiv.5
	for <qemu-devel@nongnu.org>; Thu, 24 Oct 2013 02:09:48 -0700 (PDT)
Sender: Paolo Bonzini <paolo.bonzini@gmail.com>
Message-ID: <5268E3D9.60002@redhat.com>
Date: Thu, 24 Oct 2013 10:09:45 +0100
From: Paolo Bonzini <pbonzini@redhat.com>
MIME-Version: 1.0
References: <1382600811-20043-1-git-send-email-pl@kamp.de>
	<1382600811-20043-15-git-send-email-pl@kamp.de>
In-Reply-To: <1382600811-20043-15-git-send-email-pl@kamp.de>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCHv6 14/17] block/get_block_status: fix
 BDRV_BLOCK_ZERO for unallocated blocks
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Peter Lieven <pl@kamp.de>
Cc: kwolf@redhat.com, ronniesahlberg@gmail.com, qemu-devel@nongnu.org, stefanha@redhat.com

Il 24/10/2013 08:46, Peter Lieven ha scritto:
> this patch does 2 things:
> a) only do additional call outs if BDRV_BLOCK_ZERO is not already set.
> b) use the newly introduced bdrv_has_discard_zeroes()

... whose name became bdrv_unallocated_blocks_are_zero :)  No big deal.

Paolo

> to return the
>    zero state of an unallocated block. the used callout to
>    bdrv_has_zero_init() is only valid right after bdrv_create.
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/block.c b/block.c
> index 21a992a..69a2d2b 100644
> --- a/block.c
> +++ b/block.c
> @@ -3263,8 +3263,8 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
>                                       *pnum, pnum);
>      }
>  
> -    if (!(ret & BDRV_BLOCK_DATA)) {
> -        if (bdrv_has_zero_init(bs)) {
> +    if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) {
> +        if (bdrv_unallocated_blocks_are_zero(bs)) {
>              ret |= BDRV_BLOCK_ZERO;
>          } else if (bs->backing_hd) {
>              BlockDriverState *bs2 = bs->backing_hd;
>