Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751729AbdIUKOA convert rfc822-to-8bit (ORCPT ); Thu, 21 Sep 2017 06:14:00 -0400 Received: from ozlabs.org ([103.22.144.67]:44839 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751450AbdIUKN6 (ORCPT ); Thu, 21 Sep 2017 06:13:58 -0400 From: Michael Ellerman To: Rob Landley , Christophe LEROY , Stephen Rothwell Cc: sachinp , mhocko@suse.com, peterz@infradead.org, viresh.kumar@linaro.org, Benjamin Tissoires , mingo@kernel.org, lokeshvutla@ti.com, Abdul Haleem , linux-input@vger.kernel.org, thomas.lendacky@amd.com, lauraa@codeaurora.org, keescook@chromium.org, Jiri Kosina , rostedt@goodmis.org, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, tglx@linutronix.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, tj@kernel.org, Andrew Morton , linuxppc-dev Subject: Re: [PATCH v3] Make initramfs honor CONFIG_DEVTMPFS_MOUNT In-Reply-To: References: <1495700957.9020.43.camel@abdul.in.ibm.com> <8760gp9jjl.fsf@concordia.ellerman.id.au> <20170526072437.46499fbd@canb.auug.org.au> <87a7e82d-0af5-7f9e-6bd6-7e28b238e866@landley.net> <87r2z86ykt.fsf@concordia.ellerman.id.au> <4aa9cb26-f868-0720-e5c8-3c4e08afad20@landley.net> <3ba5ddc7-d1a2-7f54-0a26-0752f3975226@c-s.fr> User-Agent: Notmuch/0.21 (https://notmuchmail.org) Date: Thu, 21 Sep 2017 20:13:55 +1000 Message-ID: <878th8cqak.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2338 Lines: 58 Rob Landley writes: > On 09/14/2017 04:17 AM, Christophe LEROY wrote: >> Le 14/09/2017 à 01:51, Rob Landley a écrit : >>> From: Rob Landley >>> >>> Make initramfs honor CONFIG_DEVTMPFS_MOUNT, and move >>> /dev/console open after devtmpfs mount. >>> >>> Add workaround for Debian bug that was copied by Ubuntu. >> >> Is that a bug only for Debian ? Why ? > > Look down, specifically this bit: > >>> v2 discussion: >>> http://lkml.iu.edu/hypermail/linux/kernel/1705.2/05611.html > > That's some discussion of version 2 of this patch, which was merged for > a while last dev cycle, then backed out again because it triggered the > same bug in a number of system init scripts: > > http://lkml.iu.edu/hypermail/linux/kernel/1705.2/07072.html > http://lkml.iu.edu/hypermail/linux/kernel/1705.3/01182.html > http://lkml.iu.edu/hypermail/linux/kernel/1705.3/01505.html > http://lkml.iu.edu/hypermail/linux/kernel/1705.3/01320.html > > All of whom copied the broken error "recovery" path from debian. If they > checked whether it was already mounted, or didn't _blank_ the /dev > directory in response to mounting the exact same filesystem over itself > giving -EBUSY, the system would work fine. Heck, if you built a kernel > with a static /dev in initramfs and no devtmpfs configured in, the > script would break things exactly the same way. The breakage is that > script takes a hammer to a perfectly functional /dev directory and then > continues the boot with an empty /dev. That's bonkers. > >> Why should a Debian bug be fixed by a workaround in the mainline kernel ? > > That was my argument last time, and the answer was "Breaking userspace > is bad, mmmkay." Even when userspace is doing something REALLY OBVIOUSLY > STUPID and it is _clearly_ their fault, as long as they got there first > they've established the status quo and it doesn't matter how silly it is. > > This was explicitly stated to me here: > > http://lkml.iu.edu/hypermail/linux/kernel/1705.3/03292.html > > I.E. don't argue with me, argue with him. :) I'm still here. And I'm still right :) No one wants their system to stop booting because of this obscure functionality. Just put it behind a new config option which defaults off. No workarounds required, no broken systems, no long email threads required. cheers