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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 9B140C433FF for ; Tue, 30 Jul 2019 00:44:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 75A2D216C8 for ; Tue, 30 Jul 2019 00:44:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729160AbfG3AoS (ORCPT ); Mon, 29 Jul 2019 20:44:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36774 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728845AbfG3AoR (ORCPT ); Mon, 29 Jul 2019 20:44:17 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 796283082E57; Tue, 30 Jul 2019 00:44:17 +0000 (UTC) Received: from ming.t460p (ovpn-8-17.pek2.redhat.com [10.72.8.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C3F706012C; Tue, 30 Jul 2019 00:44:05 +0000 (UTC) Date: Tue, 30 Jul 2019 08:44:00 +0800 From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, "Ewan D . Milne" , Bart Van Assche , Hannes Reinecke , Christoph Hellwig , Mike Snitzer , dm-devel@redhat.com, stable@vger.kernel.org Subject: Re: [PATCH V4 0/2] block/scsi/dm-rq: fix leak of request private data in dm-mpath Message-ID: <20190730004359.GA28708@ming.t460p> References: <20190725020500.4317-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190725020500.4317-1-ming.lei@redhat.com> User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Tue, 30 Jul 2019 00:44:17 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Jul 25, 2019 at 10:04:58AM +0800, Ming Lei wrote: > Hi, > > When one request is dispatched to LLD via dm-rq, if the result is > BLK_STS_*RESOURCE, dm-rq will free the request. However, LLD may allocate > private data for this request, so this way will cause memory leak. > > Add .cleanup_rq() callback and implement it in SCSI for fixing the issue, > since SCSI is the only driver which allocates private requst data in > .queue_rq() path. > > Another use case of this callback is to free the request and re-submit > bios during cpu hotplug when the hctx is dead, see the following link: > > https://lore.kernel.org/linux-block/f122e8f2-5ede-2d83-9ca0-bc713ce66d01@huawei.com/T/#t > > V4: > - add more commit log on the new .cleanup_rq callback, as suggested > by Mike > > V3: > - run .cleanup_rq() from dm-rq because this issue is dm-rq specific, > and even in future it should be still very unusual to free request > in this way. If we call .cleanup_rq() in generic rq free code(fast > path), cost will be introduced unnecessarily, also we have to > consider related race. > > V2: > - run .cleanup_rq() in blk_mq_free_request(), as suggested by Mike > > > > Ming Lei (2): > blk-mq: add callback of .cleanup_rq > scsi: implement .cleanup_rq callback > > drivers/md/dm-rq.c | 1 + > drivers/scsi/scsi_lib.c | 13 +++++++++++++ > include/linux/blk-mq.h | 13 +++++++++++++ > 3 files changed, 27 insertions(+) > > Cc: Ewan D. Milne > Cc: Bart Van Assche > Cc: Hannes Reinecke > Cc: Christoph Hellwig > Cc: Mike Snitzer > Cc: dm-devel@redhat.com > Cc: > Fixes: 396eaf21ee17 ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback") Hello Jens & guys, Ping on this fix. Thanks, Ming