From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752598AbcF1Ty4 (ORCPT ); Tue, 28 Jun 2016 15:54:56 -0400 Received: from userp1050.oracle.com ([156.151.31.82]:24967 "EHLO userp1050.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752394AbcF1Tyw (ORCPT ); Tue, 28 Jun 2016 15:54:52 -0400 Date: Tue, 28 Jun 2016 15:53:26 -0400 From: Konrad Rzeszutek Wilk To: Bob Liu Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, roger.pau@citrix.com Subject: Re: [PATCH] xen-blkfront: save uncompleted reqs in blkfront_resume() Message-ID: <20160628195325.GA14723@char.us.oracle.com> References: <1467016404-7883-1-git-send-email-bob.liu@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1467016404-7883-1-git-send-email-bob.liu@oracle.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Source-IP: userp1040.oracle.com [156.151.31.81] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 27, 2016 at 04:33:24PM +0800, Bob Liu wrote: > Uncompleted reqs used to be 'saved and resubmitted' in blkfront_recover() during > migration, but that's too later after multi-queue introduced. > > After a migrate to another host (which may not have multiqueue support), the > number of rings (block hardware queues) may be changed and the ring and shadow > structure will also be reallocated. > So that blkfront_recover() can't 'save and resubmit' the real uncompleted reqs > because shadow structure has been reallocated. > > This patch fixes this issue by moving the 'save and resubmit' logic out of > blkfront_recover() to earlier place:blkfront_resume(). > > Signed-off-by: Bob Liu Ack-ed and Reviewed-by: Konrad Rzeszutek Wilk Let me run it through some tests and if no regressions found I will ask Jens to pull it.