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,URIBL_BLOCKED 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 3608DC10F0E for ; Fri, 12 Apr 2019 03:30:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0617D20675 for ; Fri, 12 Apr 2019 03:30:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726690AbfDLDam (ORCPT ); Thu, 11 Apr 2019 23:30:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55630 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726678AbfDLDam (ORCPT ); Thu, 11 Apr 2019 23:30:42 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1677B308429B; Fri, 12 Apr 2019 03:30:42 +0000 (UTC) Received: from localhost (ovpn-8-26.pek2.redhat.com [10.72.8.26]) by smtp.corp.redhat.com (Postfix) with ESMTP id A777519C7E; Fri, 12 Apr 2019 03:30:38 +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 V5 0/9] blk-mq: fix races related with freeing queue Date: Fri, 12 Apr 2019 11:30:23 +0800 Message-Id: <20190412033032.10418-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Fri, 12 Apr 2019 03:30:42 +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. 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 (9): 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 all hctx alloction & initialization into __blk_mq_alloc_and_init_hctx 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() SCSI: don't hold device refcount in IO path block/blk-core.c | 23 +----- block/blk-mq-sysfs.c | 8 +++ block/blk-mq.c | 188 ++++++++++++++++++++++++++++-------------------- block/blk-mq.h | 2 +- drivers/scsi/scsi_lib.c | 28 +------- include/linux/blk-mq.h | 2 + include/linux/blkdev.h | 7 ++ 7 files changed, 132 insertions(+), 126 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 -- 2.9.5