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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 7CD51C43603 for ; Fri, 13 Dec 2019 09:00:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5AE14206C3 for ; Fri, 13 Dec 2019 09:00:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725810AbfLMJAu (ORCPT ); Fri, 13 Dec 2019 04:00:50 -0500 Received: from mx2.suse.de ([195.135.220.15]:48566 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725747AbfLMJAt (ORCPT ); Fri, 13 Dec 2019 04:00:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 115DDB1FC; Fri, 13 Dec 2019 09:00:48 +0000 (UTC) Subject: Re: [PATCH] xen-blkback: prevent premature module unload To: Paul Durrant , xen-devel@lists.xenproject.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Konrad Rzeszutek Wilk , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Jens Axboe References: <20191210145305.6605-1-pdurrant@amazon.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: <0a83ebaa-40b8-55f0-cff0-5aaf7bc14e98@suse.com> Date: Fri, 13 Dec 2019 10:00:44 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <20191210145305.6605-1-pdurrant@amazon.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 10.12.19 15:53, Paul Durrant wrote: > Objects allocated by xen_blkif_alloc come from the 'blkif_cache' kmem > cache. This cache is destoyed when xen-blkif is unloaded so it is > necessary to wait for the deferred free routine used for such objects to > complete. This necessity was missed in commit 14855954f636 "xen-blkback: > allow module to be cleanly unloaded". This patch fixes the problem by > taking/releasing extra module references in xen_blkif_alloc/free() > respectively. > > Signed-off-by: Paul Durrant Pushed to xen/tip.git for-linus-5.5b Juergen