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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 55B79C282DD for ; Tue, 7 Jan 2020 22:30:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20ADA206DB for ; Tue, 7 Jan 2020 22:30:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ue5Czogp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727417AbgAGWax (ORCPT ); Tue, 7 Jan 2020 17:30:53 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:38481 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727174AbgAGWaw (ORCPT ); Tue, 7 Jan 2020 17:30:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578436251; 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=FN/82vVAxc6XEGEfrEz5NnjIGWwecvczTJRijpb0J5I=; b=Ue5CzogpB5PNr7hx9NpHn5Eg2dRB02WL7pZO0XqQv5fviL52SExJ8wH1QsH4AQgf7D1Dv/ pKW6iWD+1myI7IeewlhE2o45THxv7uYqc7JrjM0yQWZWoz1w2LGFfBhJgJgYZRgiXzp4Zj w19dRzZ9Se8EAh/sgmIuZe5oCrwcjaM= 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-317-pXs9sK5SP0a-kkriMQE20A-1; Tue, 07 Jan 2020 17:30:48 -0500 X-MC-Unique: pXs9sK5SP0a-kkriMQE20A-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9BE501800D4E; Tue, 7 Jan 2020 22:30:46 +0000 (UTC) Received: from ming.t460p (ovpn-8-16.pek2.redhat.com [10.72.8.16]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 19F1A7FB65; Tue, 7 Jan 2020 22:30:40 +0000 (UTC) Date: Wed, 8 Jan 2020 06:30:35 +0800 From: Ming Lei To: Guenter Roeck Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Mason Subject: Re: [PATCH] block: fix splitting segments Message-ID: <20200107223035.GA7505@ming.t460p> References: <20191229023230.28940-1-ming.lei@redhat.com> <20200107124708.GA20285@roeck-us.net> <20200107152339.GA23622@ming.t460p> <20200107181145.GA22076@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200107181145.GA22076@roeck-us.net> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 07, 2020 at 10:11:45AM -0800, Guenter Roeck wrote: > On Tue, Jan 07, 2020 at 11:23:39PM +0800, Ming Lei wrote: > > On Tue, Jan 07, 2020 at 04:47:08AM -0800, Guenter Roeck wrote: > > > Hi, > > > > > > On Sun, Dec 29, 2019 at 10:32:30AM +0800, Ming Lei wrote: > > > > There are two issues in get_max_segment_size(): > > > > > > > > 1) the default segment boudary mask is bypassed, and some devices still > > > > require segment to not cross the default 4G boundary > > > > > > > > 2) the segment start address isn't taken into account when checking > > > > segment boundary limit > > > > > > > > Fixes the two issues. > > > > > > > > Fixes: dcebd755926b ("block: use bio_for_each_bvec() to compute multi-page bvec count") > > > > Signed-off-by: Ming Lei > > > > > > This patch, pushed into mainline as "block: fix splitting segments on > > > boundary masks", results in the following crash when booting 'versatilepb' > > > in qemu from disk. Bisect log is attached. Detailed log is at > > > https://kerneltests.org/builders/qemu-arm-master/builds/1410/steps/qemubuildcommand/logs/stdio > > > > > > Guenter > > > > > > --- > > > Crash: > > > > > > kernel BUG at block/bio.c:1885! > > > Internal error: Oops - BUG: 0 [#1] ARM > > > > Please apply the following debug patch, and post the log. > > > > Here you are: > > max_sectors 2560 max_segs 96 max_seg_size 65536 mask ffffffff > c738da80: 8c80/0 2416 28672, 0 > total sectors 56 > > (I replaced %p with %px). > Please try the following patch and see if it makes a difference. If not, replace trace_printk with printk in previous debug patch, and apply the debug patch only & post the log. diff --git a/block/blk-merge.c b/block/blk-merge.c index 347782a24a35..f152bdee9b05 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -159,12 +159,12 @@ static inline unsigned get_max_io_size(struct request_queue *q, static inline unsigned get_max_segment_size(const struct request_queue *q, struct page *start_page, - unsigned long offset) + unsigned long long offset) { unsigned long mask = queue_segment_boundary(q); offset = mask & (page_to_phys(start_page) + offset); - return min_t(unsigned long, mask - offset + 1, + return min_t(unsigned long long, mask - offset + 1, queue_max_segment_size(q)); } Thanks, Ming