From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 996B1C433F5 for ; Wed, 5 Sep 2018 16:28:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60F2E2075C for ; Wed, 5 Sep 2018 16:28:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 60F2E2075C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=CARNet.hr Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727675AbeIEU7C (ORCPT ); Wed, 5 Sep 2018 16:59:02 -0400 Received: from mail.CARNet.hr ([161.53.123.6]:48874 "EHLO mail.carnet.hr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726463AbeIEU7B (ORCPT ); Wed, 5 Sep 2018 16:59:01 -0400 Received: from cnzgrivvl-t440p.carpriv.carnet.hr ([161.53.12.131]:56480 helo=gavran.carpriv.carnet.hr) by mail.carnet.hr with smtp (Exim 4.80) (envelope-from ) id 1fxaev-0004zl-LE; Wed, 05 Sep 2018 18:28:02 +0200 Received: by gavran.carpriv.carnet.hr (Postfix, from userid 1000) id 8E2DE2012E; Wed, 5 Sep 2018 18:28:01 +0200 (CEST) Date: Wed, 5 Sep 2018 18:28:01 +0200 From: Valentin Vidic To: Roger Pau =?iso-8859-1?Q?Monn=E9?= Cc: Konrad Rzeszutek Wilk , Jens Axboe , xen-devel@lists.xenproject.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, drbd-user@lists.linbit.com Message-ID: <20180905162801.GB26705@gavran.carpriv.carnet.hr> References: <20180829065214.23546-1-Valentin.Vidic@CARNet.hr> <20180905103649.edugijsjx4v2fbxd@mac.bytemobile.com> <20180905113515.GU26705@gavran.carpriv.carnet.hr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180905113515.GU26705@gavran.carpriv.carnet.hr> User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 161.53.12.131 Subject: Re: [PATCH] xen-blkback: Switch to closed state after releasing the backing device X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 05, 2018 at 01:35:15PM +0200, Valentin Vidic wrote: > > AFAICT, this will cause the backend to never switch to 'Closed' state > > until the toolstack sets online to 0, which is not good IMO. > > > > If for example a frontend decides to close a device, the backend will > > stay in state 'Closing' until the toolstack actually removes the disk > > by setting online to 0. > > > > This will prevent resetting blk connections, as blkback will refuse to > > switch to state XenbusStateInitWait unless it's at XenbusStateClosed > > (see the XenbusStateInitialising case in frontend_changed), which will > > never be reached with your patch. Would it be possible to call xen_vbd_free before the state change? case XenbusStateClosed: xen_blkif_disconnect(be->blkif); xen_vbd_free(&be->blkif->vbd); xenbus_switch_state(dev, XenbusStateClosed); -- Valentin