From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752742AbcAUVen (ORCPT ); Thu, 21 Jan 2016 16:34:43 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:55974 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750826AbcAUVek (ORCPT ); Thu, 21 Jan 2016 16:34:40 -0500 Subject: Re: [BUG] Regression introduced with "block: split bios to max possible length" To: Stefan Haberland , , References: <56A0F1CA.4010303@linux.vnet.ibm.com> CC: , , Sebastian Ott From: Jens Axboe Message-ID: <56A14EE4.1020008@fb.com> Date: Thu, 21 Jan 2016 14:34:28 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <56A0F1CA.4010303@linux.vnet.ibm.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.52.123] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-01-21_07:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/21/2016 07:57 AM, Stefan Haberland wrote: > Hi, > > unfortunately commit e36f62042880 "block: split bios to maxpossible length" > breaks the DASD driver on s390. We expect the block requests to be > multiple > of 4k in size. With the patch applied I see the requests split up in > multiple > of 512 byte and therefore the requests get rejected and lots of I/Os fail. Sigh, that's definitely a bug. I'll take a look at it and see if I can get a tested fix in for 4.5-rc1. If not, we'll revert it, again. -- Jens Axboe