From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933007AbcFOOJC (ORCPT ); Wed, 15 Jun 2016 10:09:02 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:31396 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932934AbcFOOI6 (ORCPT ); Wed, 15 Jun 2016 10:08:58 -0400 Date: Wed, 15 Jun 2016 10:08:49 -0400 From: Konrad Rzeszutek Wilk To: Ross Lagerwall Cc: Bob Liu , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, roger.pau@citrix.com Subject: Re: [Xen-devel] [PATCH 1/2] xen-blkfront: don't call talk_to_blkback when already connected to blkback Message-ID: <20160615140849.GE9254@char.us.oracle.com> 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> <57611424.2020802@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <57611424.2020802@citrix.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 15, 2016 at 09:39:00AM +0100, Ross Lagerwall wrote: > 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. Good idea. Done. > > Thanks, > -- > Ross Lagerwall