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 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 E321AC43387 for ; Tue, 8 Jan 2019 17:24:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE0D92070B for ; Tue, 8 Jan 2019 17:24:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728436AbfAHRY0 (ORCPT ); Tue, 8 Jan 2019 12:24:26 -0500 Received: from ale.deltatee.com ([207.54.116.67]:50344 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727484AbfAHRY0 (ORCPT ); Tue, 8 Jan 2019 12:24:26 -0500 Received: from guinness.priv.deltatee.com ([172.16.1.162]) by ale.deltatee.com with esmtp (Exim 4.89) (envelope-from ) id 1ggv72-0002D1-MF; Tue, 08 Jan 2019 10:24:25 -0700 To: Christoph Hellwig Cc: Jens Axboe , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20190108131913.GA6677@lst.de> From: Logan Gunthorpe Message-ID: Date: Tue, 8 Jan 2019 10:24:24 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <20190108131913.GA6677@lst.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-CA Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 172.16.1.162 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, axboe@kernel.dk, hch@lst.de X-SA-Exim-Mail-From: logang@deltatee.com Subject: Re: Regression in v5.0-rc1: Panic at boot X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2019-01-08 6:19 a.m., Christoph Hellwig wrote: > On Mon, Jan 07, 2019 at 12:41:06PM -0700, Logan Gunthorpe wrote: >> Hey, >> >> I found a regression in v5.0-rc1 this morning. My system panics on boot. >> I've attached a log of the panic. >> >> I bisected to find the problematic commit is: >> >> Fixes: 9d037ad707ed ("block: remove req->timeout_list") >> >> But it makes no sense to me why this commit would cause a problem like >> this. I've attached a bisect log. I've also tested v5.0-rc1 with this >> commit reverted and that boots fine. >> >> The traceback seems to indicate the problem is on the bip_get_seed() >> line in t10_pi_complete(). Which suggests that bio_integrity() is >> returning NULL. > > Very odd. Can you try an experiment? Can you add padding the size > of struct timer_list to struct request to check if that makes the > problem go away? Then move the padding from the where the field > was to the end and see if that still "helps"? Ok I tried these things and they all boot without panic: 1) Add two void pointers to where 'timer_list' was 2) Add two void pointer to the end of the struct 3) Add one void pointer to the end of the struct So it seems to be a struct size issue... Logan