From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965551AbcAUO52 (ORCPT ); Thu, 21 Jan 2016 09:57:28 -0500 Received: from e06smtp07.uk.ibm.com ([195.75.94.103]:58100 "EHLO e06smtp07.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965373AbcAUO5U (ORCPT ); Thu, 21 Jan 2016 09:57:20 -0500 X-IBM-Helo: d06dlp03.portsmouth.uk.ibm.com X-IBM-MailFrom: sth@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-s390@vger.kernel.org To: keith.busch@intel.com, axboe@fb.com, torvalds@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Sebastian Ott From: Stefan Haberland Subject: [BUG] Regression introduced with "block: split bios to max possible length" Message-ID: <56A0F1CA.4010303@linux.vnet.ibm.com> Date: Thu, 21 Jan 2016 15:57:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16012114-0029-0000-0000-0000058B5741 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Could you please fix or revert the patch? We have following values set for the block queue: hw_sector_size 4096 logical_block_size 4096 minimum_io_size 4096 physical_block_size 4096 max_hw_sectors_kb 760 max_sectors_kb 760 max_segment_size 4096 max_segments 65535 Regards, Stefan