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=-8.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 2095BC67839 for ; Thu, 13 Dec 2018 01:24:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC78720851 for ; Thu, 13 Dec 2018 01:24:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC78720851 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-block-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726475AbeLMBYV (ORCPT ); Wed, 12 Dec 2018 20:24:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46714 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726337AbeLMBYV (ORCPT ); Wed, 12 Dec 2018 20:24:21 -0500 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 7417981F12; Thu, 13 Dec 2018 01:24:20 +0000 (UTC) Received: from ming.t460p (ovpn-8-24.pek2.redhat.com [10.72.8.24]) by smtp.corp.redhat.com (Postfix) with ESMTPS id EF34A60921; Thu, 13 Dec 2018 01:24:13 +0000 (UTC) Date: Thu, 13 Dec 2018 09:24:09 +0800 From: Ming Lei To: Dennis Zhou Cc: Omar Sandoval , kernel-team@fb.com, linux-block@vger.kernel.org Subject: Re: [PATCH blktests 2/2] blktests: add Ming Lei's scsi-stress-remove Message-ID: <20181213012407.GA7881@ming.t460p> References: <20181212230959.69975-1-dennis@kernel.org> <20181212230959.69975-3-dennis@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181212230959.69975-3-dennis@kernel.org> User-Agent: Mutt/1.9.1 (2017-09-22) 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 [10.5.110.25]); Thu, 13 Dec 2018 01:24:20 +0000 (UTC) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Dec 12, 2018 at 06:09:59PM -0500, Dennis Zhou wrote: > This test exposed a race condition with shutting down a request_queue > and the new blkg association. The issue ended up being that while the > request_queue will just start failing requests, blkg destruction sets > the q->root_blkg to %NULL. This caused a NPE when trying to reference > it. So to help prevent this from happening again, integrate Ming's test > into blktests so that it can more easily be ran. > > Signed-off-by: Dennis Zhou > Cc: Ming Lei > --- > tests/block/022 | 96 +++++++++++++++++++++++++++++++++++++++++++++ > tests/block/022.out | 2 + > 2 files changed, 98 insertions(+) > create mode 100755 tests/block/022 > create mode 100644 tests/block/022.out > > diff --git a/tests/block/022 b/tests/block/022 > new file mode 100755 > index 0000000..45bfff7 > --- /dev/null > +++ b/tests/block/022 > @@ -0,0 +1,96 @@ > +#!/bin/bash > +# SPDX-License-Identifier: GPL-3.0+ > +# Copyright (C) 2018 Ming Lei > +# > +# Regression test for patch "blkcg: handle dying request_queue when associating > +# a blkg" > +# > +# This tries to expose the race condition between blkg association and > +# request_queue shutdown. When a request_queue is shutdown, the corresponding > +# blkgs are destroyed. Any further associations should fail gracefully and not > +# cause a kernel panic. > + > +. tests/block/rc > +. common/scsi_debug > +. common/cgroup > + > +DESCRIPTION="test graceful shutdown of scsi_debug devices with running fio jobs" > +QUICK=1 > + > +requires() { > + _have_cgroup2_controller io && _have_scsi_debug && _have_fio > +} > + > +scsi_debug_stress_remove() { > + scsi_debug_path="/sys/bus/pseudo/drivers/scsi_debug" > + count=21 > + > + runtime=12 > + nr_fio_jobs=8 > + scsi_dbg_ndelay=10000 > + > + # set higher aio limit > + echo 524288 > /proc/sys/fs/aio-max-nr > + > + #figure out the CAN_QUEUE > + can_queue=$(((count + 1) * (count / 2) / 2)) > + > + rmmod scsi_debug > /dev/null 2>&1 > + modprobe scsi_debug virtual_gb=128 max_luns=$count \ > + ndelay=$scsi_dbg_ndelay max_queue=$can_queue > + > + # figure out scsi_debug disks > + hosts=$(ls -d /sys/bus/pseudo/drivers/scsi_debug/adapter0/host*) > + hostname=$(basename "$hosts") > + host=$(echo "$hostname" | grep -o -E '[0-9]+') > + > + sdisks=$(ls -d $scsi_debug_path/adapter*/"$hostname"/target*/*/block/*) > + disks="" > + for sd in $sdisks; do > + disks+="/dev/"$(basename "$sd") > + disks+=" " > + done > + > + use_mq=$(cat /sys/module/scsi_mod/parameters/use_blk_mq) > + if [[ $use_mq = "Y" ]]; then > + scheds=("none" "mq-deadline" "kyber") > + else > + scheds=("noop" "deadline" "cfq") > + fi You may use the following to figure out all supported io schedulers, especially we have removed all legacy io schedulers. IOSCHEDS=`sed 's/[][]//g' $Q_PATH/scheduler` Thanks, Ming