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 B3ADDC38A24 for ; Thu, 7 May 2020 15:29:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D9192082E for ; Thu, 7 May 2020 15:29:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726267AbgEGP3J (ORCPT ); Thu, 7 May 2020 11:29:09 -0400 Received: from verein.lst.de ([213.95.11.211]:47391 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725914AbgEGP3J (ORCPT ); Thu, 7 May 2020 11:29:09 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id A33A868B05; Thu, 7 May 2020 17:29:06 +0200 (CEST) Date: Thu, 7 May 2020 17:29:06 +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: <20200507152906.GA31257@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> <20200506045258.GB9846@lst.de> <10918cd1-a4a9-7872-9672-efcd28ef0751@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <10918cd1-a4a9-7872-9672-efcd28ef0751@linux.ibm.com> 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 Thu, May 07, 2020 at 05:22:28PM +0200, Stefan Haberland wrote: > OK, just thought again about your suggestion and also that > you have already been talking about a symbol lookup I just > have written a prototype that took your first two patches > as base, exports the symbol of dasd_biodasdinfo and in > ibm.c I do a kallsyms_lookup_name("dasd_biodasdinfo"). > > So I would not have to define a structure twice or rely on > MAJORs. Also we would not have to define an own file > operation only for DASD devices. > > What do you think about this? If you agree I will polish > the patches, test them and send them for review. How do you figure out a given gendisk is a DASD device? I guess dasd_biodasdinfo could just check the block_device_operations pointer first thing. That's still a little ugly, but seems the least bad idea so far, so please at least post it for discussion.