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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 1F07CC4725C for ; Wed, 6 May 2020 04:53:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 035F1206F9 for ; Wed, 6 May 2020 04:53:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725813AbgEFExC (ORCPT ); Wed, 6 May 2020 00:53:02 -0400 Received: from verein.lst.de ([213.95.11.211]:38744 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725771AbgEFExC (ORCPT ); Wed, 6 May 2020 00:53:02 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 46CD968C4E; Wed, 6 May 2020 06:52:59 +0200 (CEST) Date: Wed, 6 May 2020 06:52:58 +0200 From: Christoph Hellwig To: Stefan Haberland Cc: Christoph Hellwig , axboe@kernel.dk, linux-block@vger.kernel.org, hoeppner@linux.ibm.com, linux-s390@vger.kernel.org, heiko.carstens@de.ibm.com, gor@linux.ibm.com, borntraeger@de.ibm.com, linux-kernel@vger.kernel.org, Peter Oberparleiter Subject: Re: [PATCH 1/1] s390/dasd: remove ioctl_by_bdev from DASD driver Message-ID: <20200506045258.GB9846@lst.de> References: <20200430111754.98508-1-sth@linux.ibm.com> <20200430111754.98508-2-sth@linux.ibm.com> <20200430131351.GA24813@lst.de> <4ab11558-9f2b-02ee-d191-c9a5cc38de0f@linux.ibm.com> <70f541fe-a678-8952-0753-32707d21e337@linux.ibm.com> <20200505124423.GA26313@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, May 05, 2020 at 05:09:56PM +0200, Stefan Haberland wrote: > OK, thanks for the hint.I did not have this in mind. And I still have > to look up how this is working at all. > But isn't this only a real issue for devices with more than 16 minors > or partitions? So it should not be a problem for DASDs with our limit > of 3 partitions and the fixed amount of minors, right? > > Just tested with CONFIG_DEBUG_BLOCK_EXT_DEVT enabled and about 1000 > unlabeled devices. Did not see an issue. > > While I see the SCSI devices with MAJOR 259 and quite a random MINOR > all the DASD devices keep their MAJOR 94 and ascending MINOR. Looks like it only changes the minors, and not the majors. Still checking for major and relying on a shared structure define in different places just doesn't look maintainable. > > And compared to all the complications I think the biodasdinfo method > > is the least of all those evils. > > Are you talking about your first patch suggestion?Then I disagree. > I still do not like to force the driver to be built in if there is an > alternative. No, I mean the series that I actually sent out: https://lkml.org/lkml/2020/4/21/66 https://lkml.org/lkml/2020/4/21/68 https://lkml.org/lkml/2020/4/21/69