From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755237AbZIVGeo (ORCPT ); Tue, 22 Sep 2009 02:34:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755217AbZIVGel (ORCPT ); Tue, 22 Sep 2009 02:34:41 -0400 Received: from ozlabs.org ([203.10.76.45]:50128 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755207AbZIVGej (ORCPT ); Tue, 22 Sep 2009 02:34:39 -0400 From: Rusty Russell To: Christoph Hellwig Subject: Re: [PATCH] virtio-blk: add support for cache flush Date: Tue, 22 Sep 2009 16:04:41 +0930 User-Agent: KMail/1.11.2 (Linux/2.6.28-15-generic; KDE/4.2.2; i686; ; ) Cc: linux-kernel@vger.kernel.org References: <20090917175742.GA2416@lst.de> In-Reply-To: <20090917175742.GA2416@lst.de> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200909221604.41838.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 18 Sep 2009 03:27:42 am Christoph Hellwig wrote: > > Recent qemu has added a VIRTIO_BLK_F_FLUSH flag to advertise that the > virtual disk has a volatile write cache that needs to be flushed. In case > we see this feature implement tell the Linux block layer about the fact > and use the new VIRTIO_BLK_T_FLUSH to flush the cache when required. This > allows for an correct and simple implementation of write barriers. Thanks Christoph, this looks very nice. Applied, will push soon. > + * VIRTIO_BLK_T_OUT may be combinaed with VIRTIO_BLK_T_SCSI_CMD or > + * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of it's own > + * and may no be comined with any of the other flags. I fixed the typos here :) Thanks! Rusty.