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=-7.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 D2811C43387 for ; Mon, 24 Dec 2018 09:17:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F411218AF for ; Mon, 24 Dec 2018 09:17:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DdXWZzDD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725824AbeLXJRu (ORCPT ); Mon, 24 Dec 2018 04:17:50 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:44474 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725268AbeLXJRt (ORCPT ); Mon, 24 Dec 2018 04:17:49 -0500 Received: by mail-pg1-f196.google.com with SMTP id t13so5378793pgr.11 for ; Mon, 24 Dec 2018 01:17:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=rNXd2KUfL3/FLaqpz0NMeGk919yij6J2VNJCCgXUtiM=; b=DdXWZzDDCCapuOb2wx+mQdz+H9cEZ/8NRLrHQLkLj4Oz3vuTDgQKyxUshCNTWHvH6o v9QoYp+XMtkYDe6SmJuEs5O2ZfhdGpCIbcrEVj+k0PKUTUEgOEbb7ZgskvKHtFAl/5Bb scDd1MXRfHOiffEyct2vLpa/+fHB5uqTm4dFbFlZ8Smcii4iedX+BLxhW6GsMdHgt0dW yKAuCIvPUWOW6AuMnoKiV4eIIH51bRMeTwq37MpF2vnrwisE2H7dpRuW5MlE6ATBx9r4 SO+8DIpJhrfDuIAAWne81bdyJHzNfIkTwA/ArbAxiSHSxyPJZhOx1RcS3kFMuK+pxZ7n o3yQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=rNXd2KUfL3/FLaqpz0NMeGk919yij6J2VNJCCgXUtiM=; b=MH1FK/hYE+QH/46n14stXJZeN03BNctW6w3/DruP8WIl06dKYKdfrvoKV10N6nyLUH 22ntnftW19z0zmtI3W4zGiAxW1GCCGbrKkfsWUqh+ybyhfw+z7DEgHOMANvIRyq0YvPn ekNHxe7Ea4HUTkcBj8wpvTp1aOnVJSwxUyTRfE3eq4M96zaaz8dVQmPgI+tTFH5Q5vcC 89uNEljNwDn11TSj8UUJ8U+Zj8JZwE8hv689ZjeJJc893LKYdDOAlWVLX7LG6V1i69IK oGr0fLnwgMq46Cy24s+D0KKW2TqC2z/D82DwWEhcZpO33Vs6b6bj+80KHFUxZNvHGnc2 TzWQ== X-Gm-Message-State: AJcUuken7YIG8jiVLW8vJlmuheWd1OVfz9L5dfvKJkrnPW8svG7ApaMm Ep+Q+BBupfRHuKrzQh4vbZwOFRON X-Google-Smtp-Source: ALg8bN6Pd89klEoZBUfXeUFl/8apVUjFh/0O/tTaUVPPTSEA9t2Iqx3diKH4kOBHIe5qdjI0Kt9mQA== X-Received: by 2002:a63:df50:: with SMTP id h16mr11839830pgj.421.1545643067080; Mon, 24 Dec 2018 01:17:47 -0800 (PST) Received: from dtor-ws ([2620:15c:202:201:3adc:b08c:7acc:b325]) by smtp.gmail.com with ESMTPSA id b27sm43628149pfh.113.2018.12.24.01.17.45 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 24 Dec 2018 01:17:46 -0800 (PST) Date: Mon, 24 Dec 2018 01:17:44 -0800 From: Dmitry Torokhov To: Gabriel C Cc: Christian Brauner , Marcus Meissner , LKML , Greg KH , Linus Torvalds Subject: Re: FYI: Userland breakage caused by udev bind commit Message-ID: <20181224091744.GA122208@dtor-ws> References: <20181223164954.hib4lbchftspidsd@suse.de> <20181223171703.s7jm6fkyosnsf33z@brauner.io> <20181223180609.GA102606@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 24, 2018 at 08:31:27AM +0100, Gabriel C wrote: > Am So., 23. Dez. 2018 um 19:09 Uhr schrieb Dmitry Torokhov > : > > [ also added Linus to CC on that one too ] > > > > On Sun, Dec 23, 2018 at 06:17:04PM +0100, Christian Brauner wrote: > > > On Sun, Dec 23, 2018 at 05:49:54PM +0100, Marcus Meissner wrote: > > > > Hi, > > > > > > > > I am the maintainer of libmtp and libgphoto2 > > > > > > > > Some months ago I was made aware of this bug: > > > > https://bugs.kde.org/show_bug.cgi?id=387454 > > > > > > > > This was fallout identified to come from this kernel commit: > > > > > > > > commit 1455cf8dbfd06aa7651dcfccbadb7a093944ca65 > > > > Author: Dmitry Torokhov > > > > Date: Wed Jul 19 17:24:30 2017 -0700 > > > > > > Fwiw, the addition of {un}bind events has caused issues for > > > systemd-udevd as well and is tracked here: > > > https://github.com/systemd/systemd/issues/7587 > > > I haven't been aware of this until yesterday and it seems that so far > > > this hasn't been brought up on lkml until you did now. > > > > The fallout was caused by premature enabling of the new events in > > systemd/udev by yours truly (even though the commit has Lennart's name > > on it due to how it was merged): > > > > https://github.com/systemd/systemd/commit/9a39e1ce314d1a6f8a754f6dab040019239666a9 > > > > "Add handling for bind/unbind actions (#6720) > > > > Newer kernels will emit uevents with "bind" and "unbind" actions. These > > uevents will be issued when driver is bound to or unbound from a device. > > "Bind" events are helpful when device requires a firmware to operate > > properly, and driver is unable to create a child device before firmware > > is properly loaded. > > > > For some reason systemd validates actions and drops the ones it does not > > know, instead of passing them on through as old udev did, so we need to > > explicitly teach it about them." > > > > Similarly it is now papered over in systemd/udev until we make it > > properly handle new events: > > > > https://github.com/systemd/systemd/commit/56c886dc7ed5b2bb0882ba85136f4070545bfc1b > > > > "sd-device: ignore bind/unbind events for now > > > > Until systemd/udev are ready for the new events and do not flush entire > > device state on each new event received, we should ignore them." > > > > And how about peoples still uses systemd < 235 and newer kernels ? Should work exactly as it was with older kernels as it ignores bind/unbind attributes. > > > > > > > > > If distributions would be using libmtp and libgphoto2 udev rules > > > > that just triggered on "add" events, and not the new "bind" events, > > > > the missing "attribute tagging" of the "bind" events would confused the > > > > KDE Solid device detection and make the devices no longer detected. > > > > > > > > This did not affect distributions that rely on the newer "hwdb" > > > > device detection method. > > > > > > > > I have released fixed libmtp and libgphoto2 versions in November, so > > > > this is under control, but wanted to bring this up as a "kernel caused > > > > userland breakage". > > > > Given that we explicitly enabled these new events in systemd/udev code > > this is actually "userspace caused userspace breakage" case. > > I really do not agree with you here .. Is kernel -> userspace breakage > and while userspace is trying to workaround even much more breaks. > Not sure I follow your logic. We enabled handling new events in systemd/udev. This thing broke systemd/udev. We now disabled this new thing in systemd/udev. Thanks. -- Dmitry