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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 19FA6C43219 for ; Sun, 28 Apr 2019 08:14:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E614E2075D for ; Sun, 28 Apr 2019 08:14:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726602AbfD1IOP (ORCPT ); Sun, 28 Apr 2019 04:14:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48410 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726466AbfD1IOP (ORCPT ); Sun, 28 Apr 2019 04:14:15 -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 DD2F72DC373; Sun, 28 Apr 2019 08:14:14 +0000 (UTC) Received: from localhost (ovpn-8-32.pek2.redhat.com [10.72.8.32]) by smtp.corp.redhat.com (Postfix) with ESMTP id BDDF25D6A6; Sun, 28 Apr 2019 08:14:11 +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" Subject: [PATCH V8 0/7] blk-mq: fix races related with freeing queue Date: Sun, 28 Apr 2019 16:14:01 +0800 Message-Id: <20190428081408.27331-1-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 [10.5.110.29]); Sun, 28 Apr 2019 08:14:15 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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. V8: - merge the 4th and 5th of V7 into one patch, as suggested by Christoph - drop the 9th patch V7: - add reviewed-by and tested-by tag - rename "dead_hctx" as "unused_hctx" - check if there are live hctx in queue's release handler - only patch 6 is modified V6: - remove previous SCSI patch which will be routed via SCSI tree - add reviewed-by tag - fix one related NVMe scan vs reset race V5: - refactor blk_mq_alloc_and_init_hctx() - fix race related updating nr_hw_queues by always freeing hctx after request queue is released 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: free hw queue's resource in hctx's release handler blk-mq: split blk_mq_alloc_and_init_hctx into two parts blk-mq: always free hctx after request queue is freed 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() block/blk-core.c | 23 +----- block/blk-mq-sched.c | 9 +++ block/blk-mq-sysfs.c | 8 +++ block/blk-mq.c | 188 +++++++++++++++++++++++++++++-------------------- block/blk-mq.h | 2 +- include/linux/blk-mq.h | 2 + include/linux/blkdev.h | 7 ++ 7 files changed, 139 insertions(+), 100 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 , -- 2.9.5