From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([140.186.70.92]:44015)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1RDyH9-0006bK-9f
	for qemu-devel@nongnu.org; Wed, 12 Oct 2011 08:51:12 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1RDyH8-00050T-7C
	for qemu-devel@nongnu.org; Wed, 12 Oct 2011 08:51:11 -0400
Received: from mx1.redhat.com ([209.132.183.28]:62931)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <kwolf@redhat.com>) id 1RDyH7-00050G-U6
	for qemu-devel@nongnu.org; Wed, 12 Oct 2011 08:51:10 -0400
Message-ID: <4E958DD6.5000805@redhat.com>
Date: Wed, 12 Oct 2011 14:53:42 +0200
From: Kevin Wolf <kwolf@redhat.com>
MIME-Version: 1.0
References: <1317831427-477-1-git-send-email-stefanha@linux.vnet.ibm.com>
	<1317831427-477-4-git-send-email-stefanha@linux.vnet.ibm.com>
In-Reply-To: <1317831427-477-4-git-send-email-stefanha@linux.vnet.ibm.com>
Content-Type: text/plain; charset=ISO-8859-15
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH 3/6] block: switch bdrv_read()/bdrv_write()
	to coroutines
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@linux.vnet.ibm.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>, Marcelo Tosatti <mtosatti@redhat.com>, qemu-devel@nongnu.org, Zhi Yong Wu <wuzhy@cn.ibm.com>, Avi Kivity <avi@redhat.com>, Christoph Hellwig <hch@lst.de>

Am 05.10.2011 18:17, schrieb Stefan Hajnoczi:
> The bdrv_read()/bdrv_write() functions call .bdrv_read()/.bdrv_write().
> They should go through bdrv_co_do_readv() and bdrv_co_do_writev()
> instead in order to unify request processing code across sync, aio, and
> coroutine interfaces.  This is also an important step towards removing
> BlockDriverState .bdrv_read()/.bdrv_write() in the future.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

This breaks drivers that only provide synchronous .bdrv_read/write.
Attempts to read or write anything results in endless recursion.

Kevin