From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=50321 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1OOTQR-0008B9-V0
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 06:31:28 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69)
	(envelope-from <kwolf@redhat.com>) id 1OOTQM-0007P6-Hn
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 06:31:23 -0400
Received: from mx1.redhat.com ([209.132.183.28]:35944)
	by eggs.gnu.org with esmtp (Exim 4.69)
	(envelope-from <kwolf@redhat.com>) id 1OOTQM-0007P0-BD
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 06:31:18 -0400
Message-ID: <4C175664.7050107@redhat.com>
Date: Tue, 15 Jun 2010 12:31:00 +0200
From: Kevin Wolf <kwolf@redhat.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [PATCH 1/2] qcow2: Simplify image creation
References: <1276526595-32658-1-git-send-email-kwolf@redhat.com>	<1276526595-32658-2-git-send-email-kwolf@redhat.com>
	<AANLkTimS4vfx8V-9SG4JvTUQr6GMytbwbwgBzZjVu1dJ@mail.gmail.com>
In-Reply-To: <AANLkTimS4vfx8V-9SG4JvTUQr6GMytbwbwgBzZjVu1dJ@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/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: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: qemu-devel@nongnu.org, quintela@redhat.com

Am 15.06.2010 12:14, schrieb Stefan Hajnoczi:
> On Mon, Jun 14, 2010 at 3:43 PM, Kevin Wolf <kwolf@redhat.com> wrote:
>> Instead of doing lots of magic for setting up initial refcount blocks and stuff
>> create a minimal (inconsistent) image, open it and initialize the rest with
>> regular qcow2 functions.
> 
> Nice idea.
> 
>> +    ret = bdrv_pwrite(bs, 0, &header, sizeof(header));
>> +    if (ret < 0) {
>> +        return ret;
>> +    }
> 
> The bs is not closed on error.  

Right, will fix the missing bdrv_delete here and in other cases.

> Also, this function will leave a
> partially created file on disk if it fails.

As did the old one, and the bdrv_create functions of most other formats
behave the same. We could implement a bdrv_remove to remove that file
again, but it would be ununsed except for these very unlikely error
cases. If you can't access the disk, usually the bdrv_create_file would
fail already.

Kevin