From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:53577)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <vsementsov@odin.com>) id 1ZWMvR-0002tO-1R
	for qemu-devel@nongnu.org; Mon, 31 Aug 2015 07:06:57 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <vsementsov@odin.com>) id 1ZWMvN-000263-1y
	for qemu-devel@nongnu.org; Mon, 31 Aug 2015 07:06:56 -0400
Received: from relay.parallels.com ([195.214.232.42]:41344)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <vsementsov@odin.com>) id 1ZWMvM-000258-PW
	for qemu-devel@nongnu.org; Mon, 31 Aug 2015 07:06:52 -0400
Message-ID: <55E43538.6020703@virtuozzo.com>
Date: Mon, 31 Aug 2015 14:06:32 +0300
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
MIME-Version: 1.0
References: <1433776886-27239-1-git-send-email-vsementsov@virtuozzo.com>
	<1433776886-27239-7-git-send-email-vsementsov@virtuozzo.com>
	<20150609155014.GF3181@stefanha-thinkpad.redhat.com>
	<55DEC00C.8010100@virtuozzo.com>
In-Reply-To: <55DEC00C.8010100@virtuozzo.com>
Content-Type: text/plain; charset="windows-1252"; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH 6/8] qcow2: add autoclear bit for dirty
	bitmaps
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: Stefan Hajnoczi <stefanha@gmail.com>
Cc: kwolf@redhat.com, qemu-devel@nongnu.org, Vladimir Sementsov-Ogievskiy <vsementsov@parallels.com>, stefanha@redhat.com, den@openvz.org, pbonzini@redhat.com, jsnow@redhat.com

On 27.08.2015 10:45, Vladimir Sementsov-Ogievskiy wrote:
> On 09.06.2015 18:50, Stefan Hajnoczi wrote:
>> On Mon, Jun 08, 2015 at 06:21:24PM +0300, Vladimir 
>> Sementsov-Ogievskiy wrote:
>>> diff --git a/block/qcow2.c b/block/qcow2.c
>>> index 406e55d..f85a55a 100644
>>> --- a/block/qcow2.c
>>> +++ b/block/qcow2.c
>>> @@ -182,6 +182,14 @@ static int 
>>> qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
>>>                   return ret;
>>>               }
>>>   +            if (!(s->autoclear_features & 
>>> QCOW2_AUTOCLEAR_DIRTY_BITMAPS) &&
>>> +                s->nb_dirty_bitmaps > 0) {
>>> +                ret = qcow2_delete_all_dirty_bitmaps(bs, errp);
>>> +                if (ret < 0) {
>>> +                    return ret;
>>> +                }
>>> +            }
>>> +
>> What if the file is read-only?
>>
>> We shouldn't modify the file in qcow2_read_extensions().
> But where? In qcow2_open? Or nowhere? I think auto clear extensions 
> should be cleared automatically..
>

May be, move clearing to qemu-img, and just warn here?

-- 
Best regards,
Vladimir
* now, @virtuozzo.com instead of @parallels.com. Sorry for this inconvenience.