[systemd-devel] EXT :Re: Systemd udev add tag for boot device

[Boyce, Kevin P [US] (AS)]

Lennart,

Is it not possible for a udev rule like the following to work?  MYVAR has been imported (with value sda) and is visible for the block device.  I verified it with udevadm info --query=name -x sda.

KERNEL=="%E{MYVAR}", TAG+="test"

The end result is that this rule doesn't fire.  Could someone explain why?  According to the man pages, I think this should work.

Kind Regards,
Kevin

-----Original Message-----
From: Lennart Poettering <lennart at poettering.net> 
Sent: Monday, January 13, 2020 10:54 AM
To: Boyce, Kevin P [US] (AS) <Kevin.Boyce at ngc.com>
Cc: systemd-devel at lists.freedesktop.org
Subject: Re: EXT :Re: [systemd-devel] Systemd udev add tag for boot device

On Mo, 13.01.20 09:10, Boyce, Kevin P. (AS) (kevin.boyce at ngc.com) wrote:

> Thank you Lennart.
>
> I'm thinking I will create my own sort of "built-in" command that can 
> parse /proc/cmdline to look for the root= variable early in udev rules 
> so I can create the tag.

So, systemd has to for determining the backing file system of some directory and this is used by gpt-auto-generator for finding the block device backing / or /usr/. I figure you want something like that?

We don't expose that directly though, and it's limited, since we do not cover complex storage. We do cover btrfs though.

Lennart

--
Lennart Poettering, Berlin