From patchwork Thu Apr 4 08:43:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10885267 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2880E1669 for ; Thu, 4 Apr 2019 08:43:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1A27A28904 for ; Thu, 4 Apr 2019 08:43:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0DB5F28A22; Thu, 4 Apr 2019 08:43:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B3272289EC for ; Thu, 4 Apr 2019 08:43:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728019AbfDDInb (ORCPT ); Thu, 4 Apr 2019 04:43:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37960 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725914AbfDDInb (ORCPT ); Thu, 4 Apr 2019 04:43:31 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 57971307E048; Thu, 4 Apr 2019 08:43:31 +0000 (UTC) Received: from localhost (ovpn-8-21.pek2.redhat.com [10.72.8.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5B34A62671; Thu, 4 Apr 2019 08:43:26 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , Dongli Zhang , James Smart , Bart Van Assche , linux-scsi@vger.kernel.org, "Martin K . Petersen" , Christoph Hellwig , "James E . J . Bottomley" , jianchao wang Subject: [PATCH V4 0/7] blk-mq: fix races related with freeing queue Date: Thu, 4 Apr 2019 16:43:13 +0800 Message-Id: <20190404084320.24681-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Thu, 04 Apr 2019 08:43:31 +0000 (UTC) Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi, Since 45a9c9d909b2 ("blk-mq: Fix a use-after-free"), run queue isn't allowed during cleanup queue even though queue refcount is held. This change has caused lots of kernel oops triggered in run queue path, turns out it isn't easy to fix them all. So move freeing of hw queue resources into hctx's release handler, then the above issue is fixed. Meantime, this way is safe given freeing hw queue resource doesn't require tags. V3 covers more races. V4: - add patch for fixing potential use-after-free in blk_mq_update_nr_hw_queues - fix comment in the last patch V3: - cancel q->requeue_work in queue's release handler - cancel hctx->run_work in hctx's release handler - add patch 1 for fixing race in plug code path - the last patch is added for avoiding to grab SCSI's refcont in IO path V2: - moving freeing hw queue resources into hctx's release handler Ming Lei (7): blk-mq: grab .q_usage_counter when queuing request from plug code path blk-mq: move cancel of requeue_work into blk_mq_release blk-mq: quiesce queue before updating nr_hw_queues blk-mq: free hw queue's resource in hctx's release handler blk-mq: move cancel of hctx->run_work into blk_mq_hw_sysfs_release block: don't drain in-progress dispatch in blk_cleanup_queue() SCSI: don't hold device refcount in IO path block/blk-core.c | 23 +---------------------- block/blk-mq-sysfs.c | 8 ++++++++ block/blk-mq.c | 25 +++++++++++++++++-------- block/blk-mq.h | 2 +- drivers/scsi/scsi_lib.c | 28 ++-------------------------- 5 files changed, 29 insertions(+), 57 deletions(-) Cc: Dongli Zhang Cc: James Smart Cc: Bart Van Assche Cc: linux-scsi@vger.kernel.org, Cc: Martin K . Petersen , Cc: Christoph Hellwig , Cc: James E . J . Bottomley , Cc: jianchao wang