From patchwork Wed Apr 3 10:26:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10883231 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 AB24617E9 for ; Wed, 3 Apr 2019 10:26:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8CEA7289D0 for ; Wed, 3 Apr 2019 10:26:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7FFB8289D3; Wed, 3 Apr 2019 10:26:18 +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=ham 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 1CAA1289D0 for ; Wed, 3 Apr 2019 10:26:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726328AbfDCK0R (ORCPT ); Wed, 3 Apr 2019 06:26:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34762 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726199AbfDCK0R (ORCPT ); Wed, 3 Apr 2019 06:26:17 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 77B3730832C2; Wed, 3 Apr 2019 10:26:17 +0000 (UTC) Received: from localhost (ovpn-8-25.pek2.redhat.com [10.72.8.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id B6989608BD; Wed, 3 Apr 2019 10:26:14 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei Subject: [PATCH V3 0/6] blk-mq: fix races related with freeing queue Date: Wed, 3 Apr 2019 18:26:03 +0800 Message-Id: <20190403102609.18707-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Wed, 03 Apr 2019 10:26:17 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@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. 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 (6): 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: 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 | 16 ++++++++++------ block/blk-mq.h | 2 +- drivers/scsi/scsi_lib.c | 30 ++++++------------------------ 5 files changed, 26 insertions(+), 53 deletions(-)