From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: SCSI regression in 4.11 Date: Mon, 27 Feb 2017 19:16:49 -0700 Message-ID: References: <20170227152955.1362aabb@xeon-e3> <20170227171931.30b9f619@xeon-e3> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: Received: from mail-pf0-f182.google.com ([209.85.192.182]:36514 "EHLO mail-pf0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751547AbdB1CRJ (ORCPT ); Mon, 27 Feb 2017 21:17:09 -0500 Received: by mail-pf0-f182.google.com with SMTP id x66so842824pfb.3 for ; Mon, 27 Feb 2017 18:16:56 -0800 (PST) In-Reply-To: <20170227171931.30b9f619@xeon-e3> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Stephen Hemminger , Christoph Hellwig , Linus Torvalds , "James E.J. Bottomley" , "Martin K. Petersen" , "K. Y. Srinivasan" , Dexuan Cui , Long Li , Josh Poulson , v-adsuho@microsoft.com Cc: linux-scsi@vger.kernel.org On 02/27/2017 06:19 PM, Stephen Hemminger wrote: > On Mon, 27 Feb 2017 15:30:30 -0800 > Stephen Hemminger wrote: > >> Something in SCSI in 4.11 broke booting on Hyper-V Generation 2 VM with 8 VCPU and 4G of memory. >> Both Linus's current tree (4.11 pre-rc1) and linux-next fail in a similar manner. It looks like some error >> in SCSI device detection because there is only a single device. >> >> The offending commit causing the regression is: >> >> $ git bisect bad >> e9c787e65c0c36529745be47d490d998b4b6e589 is the first bad commit >> commit e9c787e65c0c36529745be47d490d998b4b6e589 >> Author: Christoph Hellwig >> Date: Mon Jan 2 21:55:26 2017 +0300 >> >> scsi: allocate scsi_cmnd structures as part of struct request >> >> Rely on the new block layer functionality to allocate additional driver >> specific data behind struct request instead of implementing it in SCSI >> itѕelf. >> >> Signed-off-by: Christoph Hellwig >> Acked-by: Martin K. Petersen >> Reviewed-by: Hannes Reinecke >> Signed-off-by: Jens Axboe >> >> :040000 040000 6ff016fcdae227efeb19c1c301b17ccd7ea35da6 70d79f99d9b79ecf4dccbe067fc697219f5c78da M drivers >> :040000 040000 a672ff52df8b2c211b3f98cae4a88d8a96ccde0b 1aaaed7de0994f597c7f8290c722a0b4a7789429 M include >> >> I checked and tree is current and up to date and includes >> commit ee5242360424b9b967454e9183767323d10cf985 >> Author: Christoph Hellwig >> Date: Tue Feb 21 10:04:55 2017 +0100 >> >> scsi: zero per-cmd driver data before each I/O >> >> Kernel config is attached. It started with Ubuntu config, but then did localmodconfig and pruned >> out unnecessary stuff. >> > > This problem I am seeing looks like the one addressed by: > > Fixes: ee5242360424 ("scsi: zero per-cmd driver data before each I/O") > > but that is already in linux-next. > > Noticed another place where memset(of the data was being done not the extra bits. > Tried this, but didn't fix it either... Yeah, that fix is already in Linus's tree. But it does look like a replica of what Dexuan reported. Out of curiosity, does it boot if you enable CONFIG_SCSI_MQ_DEFAULT? Christoph, looks like the previous fix wasn't complete... -- Jens Axboe