From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1KTLGu-0001ON-BP
	for qemu-devel@nongnu.org; Wed, 13 Aug 2008 14:40:36 -0400
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1KTLGs-0001NO-LN
	for qemu-devel@nongnu.org; Wed, 13 Aug 2008 14:40:35 -0400
Received: from [199.232.76.173] (port=33687 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1KTLGr-0001ND-S0
	for qemu-devel@nongnu.org; Wed, 13 Aug 2008 14:40:34 -0400
Received: from il.qumranet.com ([212.179.150.194]:38448)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <avi@qumranet.com>) id 1KTLGr-0002Ec-7B
	for qemu-devel@nongnu.org; Wed, 13 Aug 2008 14:40:33 -0400
Message-ID: <48A32AA2.6030902@qumranet.com>
Date: Wed, 13 Aug 2008 21:40:34 +0300
From: Avi Kivity <avi@qumranet.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] [PATCH] Flush pending AIO on reboot and shutdown.
References: <20080813132358.17672.68212.stgit@gleb-debian.qumranet.com.qumranet.com>	<48A2E732.4040501@codemonkey.ws>	<20080813141346.GC17567@minantech.com>	<48A2F89A.20609@codemonkey.ws>	<20080813152329.GG17567@minantech.com>	<48A30395.6060706@codemonkey.ws>
	<20080813183544.GA29998@minantech.com>
In-Reply-To: <20080813183544.GA29998@minantech.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Reply-To: qemu-devel@nongnu.org
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.gnu.org/pipermail/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: qemu-devel@nongnu.org

Gleb Natapov wrote:
> but what bother me is that we
> consciously drop user data that we can easily save. Why? Real HW tries
> hard to save every bit of user data and we just decided to drop it. The
> difference between cancel or complete a request may be corrupted or not
> corrupted file system after a crash.
>
>   

If a guest didn't wait for an I/O to complete, it shouldn't expect it to 
be on disk.

Of course, we can have the IDE layer wait instead of cancelling, which 
will get the request onto the disk.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.