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=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,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 1F75BC49361 for ; Mon, 14 Jun 2021 21:55:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E958E61166 for ; Mon, 14 Jun 2021 21:55:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231688AbhFNV5v (ORCPT ); Mon, 14 Jun 2021 17:57:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:51572 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231664AbhFNV5m (ORCPT ); Mon, 14 Jun 2021 17:57:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623707739; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KLVO0uHHSAtgtB8zfOsGh07ySHX0in1v8TZBqoRBniI=; b=edl2qqN/JNKjAyZc5aLGW3AHkHKqbPo2tQKrmxqp1oZ2kvAEkbNyAqLyofSb2OH3ppXAuX FLzf+KMAgeJYgtvUg6yo/FF2IzA/YE5bIQkxDlnD240THGtX87zarQ4id/03XDmW8zOV9i B3uAWwFyhNbVmAucA720lE1jGnJaOzg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-283-6WVpP6FrMaOdg18wXb4_Rw-1; Mon, 14 Jun 2021 17:55:35 -0400 X-MC-Unique: 6WVpP6FrMaOdg18wXb4_Rw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7F6E21084F40; Mon, 14 Jun 2021 21:55:34 +0000 (UTC) Received: from T590 (ovpn-12-39.pek2.redhat.com [10.72.12.39]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 148E060C4A; Mon, 14 Jun 2021 21:55:24 +0000 (UTC) Date: Tue, 15 Jun 2021 05:55:20 +0800 From: Ming Lei To: Jens Axboe , Christoph Hellwig Cc: linux-block@vger.kernel.org, Yi Zhang , Bart Van Assche Subject: Re: [PATCH V3 0/2] block: fix race between adding wbt and normal IO Message-ID: References: <20210609015822.103433-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210609015822.103433-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Jun 09, 2021 at 09:58:20AM +0800, Ming Lei wrote: > Hello, > > Yi reported several kernel panics on: > > [16687.001777] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 > ... > [16687.163549] pc : __rq_qos_track+0x38/0x60 > > or > > [ 997.690455] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 > ... > [ 997.850347] pc : __rq_qos_done+0x2c/0x50 > > Turns out it is caused by race between adding wbt and normal IO. > > Fix the issue by freezing request queue when adding/deleting rq qos. > > V3: > - use ->queue_lock for protecting concurrent adding/deleting rqos on > same queue > > V2: > - switch to the approach of freezing queue, which is more generic > than V1. > > > > Ming Lei (2): > block: fix race between adding/removing rq qos and normal IO > block: mark queue init done at the end of blk_register_queue > > block/blk-rq-qos.h | 24 ++++++++++++++++++++++++ > block/blk-sysfs.c | 29 +++++++++++++++-------------- > 2 files changed, 39 insertions(+), 14 deletions(-) > > Cc: Yi Zhang > Cc: Bart Van Assche Hello Jens, Any chance to merge the fixes if you are fine? Thanks, Ming