Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753939Ab0ALQvs (ORCPT ); Tue, 12 Jan 2010 11:51:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753533Ab0ALQvr (ORCPT ); Tue, 12 Jan 2010 11:51:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:31578 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752453Ab0ALQvr (ORCPT ); Tue, 12 Jan 2010 11:51:47 -0500 Message-ID: <4B4CA886.8070808@redhat.com> Date: Tue, 12 Jan 2010 17:51:18 +0100 From: Michal Novotny User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.5) Gecko/20091209 Fedora/3.0-3.fc11 Thunderbird/3.0 MIME-Version: 1.0 To: Christoph Hellwig CC: Ric Wheeler , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] extend e2fsprogs functionality to add EXT2_FLAG_DIRECT option References: <4B4B84E2.1050508@redhat.com> <4B4C54DC.4040006@redhat.com> <4B4C6429.6090803@redhat.com> <4B4C67F5.1020009@redhat.com> <20100112122319.GA20596@infradead.org> <4B4C6B70.1050205@redhat.com> <20100112124600.GA7151@infradead.org> <4B4C7297.5030905@redhat.com> <20100112163828.GA14633@infradead.org> <4B4CA6A9.3030401@redhat.com> <20100112164748.GA26895@infradead.org> In-Reply-To: <20100112164748.GA26895@infradead.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1015 Lines: 23 On 01/12/2010 05:47 PM, Christoph Hellwig wrote: > On Tue, Jan 12, 2010 at 05:43:21PM +0100, Michal Novotny wrote: > >> So, do you think the problem is in the Xen backend drivers and to make >> it working right in Xen the driver fix is needed? >> > Yes, the Xen blkback driver just submits I/O directly without using > the right interfaces to force cache coherency. It might be relatively > easy to hack a call in to flush all caches when it starts up, but given > how it bypasses all abstractions it's almost impossible to give full > coherency as if using the normal block device interfaces. > > Ok, this way the fix to the drivers should be done. Thanks for your investigation. I just forwarded your reply to other members of my team. Thanks, Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/