Re: FYI: Userland breakage caused by udev bind commit

From: Christian Brauner
Date: Sun Dec 23 2018 - 12:17:13 EST


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 <dmitry.torokhov@xxxxxxxxx>
> 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.

>
> 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".
>
> Ciao, Marcus