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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=ham 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 C4587C64E8A for ; Thu, 3 Dec 2020 01:49:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6D86C20B80 for ; Thu, 3 Dec 2020 01:49:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726479AbgLCBtN (ORCPT ); Wed, 2 Dec 2020 20:49:13 -0500 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:34710 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726312AbgLCBtN (ORCPT ); Wed, 2 Dec 2020 20:49:13 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R771e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04395;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0UHMcpTK_1606960110; Received: from admindeMacBook-Pro-2.local(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0UHMcpTK_1606960110) by smtp.aliyun-inc.com(127.0.0.1); Thu, 03 Dec 2020 09:48:31 +0800 Subject: Re: [dm-devel] dm: use gcd() to fix chunk_sectors limit stacking To: Mike Snitzer Cc: linux-block@vger.kernel.org, joseph.qi@linux.alibaba.com, dm-devel@redhat.com References: <20201201160709.31748-1-snitzer@redhat.com> <20201202033855.60882-1-jefflexu@linux.alibaba.com> <20201202033855.60882-2-jefflexu@linux.alibaba.com> <20201202050343.GA20535@redhat.com> <7326607a-b687-3989-dee7-cf469ab37ac4@linux.alibaba.com> <20201202151112.GD20535@redhat.com> From: JeffleXu Message-ID: <353a132b-1430-60b0-3f17-979af1b8dd22@linux.alibaba.com> Date: Thu, 3 Dec 2020 09:48:30 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <20201202151112.GD20535@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 12/2/20 11:11 PM, Mike Snitzer wrote: > On Wed, Dec 02 2020 at 2:10am -0500, > JeffleXu wrote: > >> >> >> On 12/2/20 1:03 PM, Mike Snitzer wrote: >>> What you've done here is fairly chaotic/disruptive: >>> 1) you emailed a patch out that isn't needed or ideal, I dealt already >>> staged a DM fix in linux-next for 5.10-rcX, see: >>> https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-5.10-rcX&id=f28de262ddf09b635095bdeaf0e07ff507b3c41b >> >> Then ti->type->io_hints() is still bypassed when type->iterate_devices() >> not defined? > > Yes, the stacking of limits really is tightly coupled to device-based > influence. Hypothetically some DM target that doesn't remap to any data > devices may want to override limits... in practice there isn't a need > for this. If that changes we can take action to accommodate it.. but I'm > definitely not interested in modifying DM core in this area when there > isn't a demonstrated need. Thanks. -- Thanks, Jeffle