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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 DACE2C33C9E for ; Tue, 7 Jan 2020 23:06:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB0CA20715 for ; Tue, 7 Jan 2020 23:06:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="p/+8IKC9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727308AbgAGXGf (ORCPT ); Tue, 7 Jan 2020 18:06:35 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:42310 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727074AbgAGXGf (ORCPT ); Tue, 7 Jan 2020 18:06:35 -0500 Received: by mail-pg1-f196.google.com with SMTP id s64so573904pgb.9; Tue, 07 Jan 2020 15:06:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Hn2E8TmwJXOaHmoVzcv3GA0FCQtIxiHPvPOQL+N/lCU=; b=p/+8IKC9TQursDveFr01JEpQ5bcHvMZC1uRj+JHRYHTReXw1CgY/77BhuOl5n9glJ0 3ZHm3fdP/Dj9r+q43pCD+PxOVN11yRXwc9mTgcWI/yiPlgbiqcUOeH01Q2MWOJ1Xb75Q Rzb/1xI7I4IzVD4l/Wu86DQcK99NLvuTH/JTnDk5FLSveA2j01BQwNluDxUhV6XzChrf rDASSkkE1hHV/OGPSlR5RuHTUoQDjNYXZ24klfluQfkus1An7uy4UfbxljWYfm/ZIYBJ KpYfymAq+fvYouWkB+37JnekbzODcbo5NPJndmXDAH3sbV2bnPxmnfc9JRnpsq6fh+On r0oA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=Hn2E8TmwJXOaHmoVzcv3GA0FCQtIxiHPvPOQL+N/lCU=; b=V21vq5lM3vtqYMbFFqkri7W7N8gmlupc/iLkAsOXhOHO3svX0HOfJOIV0eaLGX3jDu jDAaU+CWF/TfzwPeFgO7aUtMuwYSm2hlKXcENGHcuXe+wT8nSYPKEf3Lm08lQsfQjIZy n0RRlszXTOsRicdlh5Ldv12MChxwW2whjwcpgPXqOyySyZ60bLWmI8ktjBcq026pHFPr w3kYjfpgfbZGdvtMiNd5rxW1lVy/4XvjPXxBdG0KBeYtE6LLGA3c0WATIhvc808EYuv4 ysKAmPHOovZPGnYMpdAWr3P3nKNtfMFRjLUmCZ9BjDWHWuAxijhG6YRfsv+5sQar9GPL EXUg== X-Gm-Message-State: APjAAAVOk9KYlMJVnkmQD/lPMHiWSSmPe2X66XqeZb5NTv07nLrQhc8c rrdtGbrazihGdVqMUcdllfw= X-Google-Smtp-Source: APXvYqwQqKa9HG/4s4SU7tc2itIOKHHboTkZCG0qR76TQBRpNOLwB22DwvbBtUOwPSIGXgrYf+k7gA== X-Received: by 2002:aa7:9d87:: with SMTP id f7mr1785033pfq.138.1578438394934; Tue, 07 Jan 2020 15:06:34 -0800 (PST) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id o19sm30654167pjr.2.2020.01.07.15.06.33 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 07 Jan 2020 15:06:33 -0800 (PST) Date: Tue, 7 Jan 2020 15:06:32 -0800 From: Guenter Roeck To: Ming Lei Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Mason Subject: Re: [PATCH] block: fix splitting segments Message-ID: <20200107230632.GA24960@roeck-us.net> References: <20191229023230.28940-1-ming.lei@redhat.com> <20200107124708.GA20285@roeck-us.net> <20200107152339.GA23622@ming.t460p> <20200107181145.GA22076@roeck-us.net> <20200107223035.GA7505@ming.t460p> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200107223035.GA7505@ming.t460p> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 08, 2020 at 06:30:35AM +0800, Ming Lei wrote: > 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. > The patch below fixes the problem for me. Tested-by: Guenter Roeck Guenter > 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 >