From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753396AbcFOIjE (ORCPT ); Wed, 15 Jun 2016 04:39:04 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:4471 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932380AbcFOIjC (ORCPT ); Wed, 15 Jun 2016 04:39:02 -0400 X-IronPort-AV: E=Sophos;i="5.26,475,1459814400"; d="scan'208";a="367399893" Subject: Re: [Xen-devel] [PATCH 1/2] xen-blkfront: don't call talk_to_blkback when already connected to blkback To: Konrad Rzeszutek Wilk , Bob Liu References: <1464685157-30738-1-git-send-email-bob.liu@oracle.com> <20160531203307.GC23808@char.us.oracle.com> <574E7763.9060001@oracle.com> <20160607152524.GA10281@localhost.localdomain> <5757BF4E.9080307@oracle.com> <20160608144739.GD17027@char.us.oracle.com> CC: , , From: Ross Lagerwall Message-ID: <57611424.2020802@citrix.com> Date: Wed, 15 Jun 2016 09:39:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <20160608144739.GD17027@char.us.oracle.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/08/2016 03:47 PM, Konrad Rzeszutek Wilk wrote: > On Wed, Jun 08, 2016 at 02:46:38PM +0800, Bob Liu wrote: >> >> On 06/07/2016 11:25 PM, Konrad Rzeszutek Wilk wrote: >>> On Wed, Jun 01, 2016 at 01:49:23PM +0800, Bob Liu wrote: >>>> >>>> On 06/01/2016 04:33 AM, Konrad Rzeszutek Wilk wrote: >>>>> On Tue, May 31, 2016 at 04:59:16PM +0800, Bob Liu wrote: >>>>>> Sometimes blkfont may receive twice blkback_changed() notification after >>>>>> migration, then talk_to_blkback() will be called twice too and confused >>>>>> xen-blkback. >>>>> ... snip >>>> But sometimes blkfront receives >>>> blkback_changed() event more than once! >>> >>> I think I know why. The udev scripts that get invoked when when >>> we attach a disk are a bit custom. As such I think they just >>> revalidate the size leading to this. >>> >>> And this 'poke-at-XenbusStateConnected' state multiple times >>> is allowed. It is used to signal disk changes (or just to revalidate). >>> Hence it does not matter why really - we need to deal with this. >>> >>> I modified your patch a bit and are testing it: >>> >> >> Looks much better, thank you very much! > > Great! I also had it tested overnight and there was no hitch will send it > out soon. > I'd like to request that this patch is backported to Linux 4.5 and both of the patches in this series are backported to Linux 4.6. This is affecting Debian Testing (using Linux 4.6). It fails to recover its disk when resuming or migrating. Thanks, -- Ross Lagerwall