[systemd-devel] 'udevadm test' removes/adds by-id/by-path links

[Kay Sievers]

On Thu, Nov 28, 2013 at 11:36 AM, Robert Milasan <rmilasan at suse.com> wrote:
> Hello,
>   when running 'udevadm test /sys/block/sdb --action=remove' then links
>   to the device node in /dev/disk/{by-id,by-path} are being removed and
>   running udevadm test with action=add, the links are re-added.
>
> robert at viper:~> ls -l /dev/disk/by-id/|grep sdb
> lrwxrwxrwx 1 root root  9 Nov 28 11:13
> usb-Corsair_Flash_Voyager_00000025000057-0:0 -> ../../sdb
> lrwxrwxrwx 1 root root 10 Nov 28 10:50
> usb-Corsair_Flash_Voyager_00000025000057-0:0-part1 -> ../../sdb1
>
> robert at viper:~> sudo udevadm test /sys/block/sdb --action=remove
>>/dev/null 2>&1
> robert at viper:~> ls -l /dev/disk/by-id/|grep sdb
> lrwxrwxrwx 1 root root 10 Nov 28 10:50
> usb-Corsair_Flash_Voyager_00000025000057-0:0-part1 -> ../../sdb1
>
> robert at viper:~> sudo udevadm test /sys/block/sdb --action=add
>>/dev/null 2>&1
> robert at viper:~> ls -l /dev/disk/by-id/|grep sdb
> lrwxrwxrwx 1 root root  9 Nov 28 11:34
> usb-Corsair_Flash_Voyager_00000025000057-0:0 -> ../../sdb
> lrwxrwxrwx 1 root root 10 Nov 28 10:50
> usb-Corsair_Flash_Voyager_00000025000057-0:0-part1 -> ../../sdb1
>
>  As you can see on action=remove, the link to sdb device node has been
>  removed and on action=add, the link as been re-added.
>
>  As I am running 'udevadm test', I would think, that this is only a test
>  and the links or anything related to this test suppose to be fake,
>  meaning nothing really should be removed/added.
>
>  Is this a known functionality of 'udevadm test' or it's a bug?

Sure, "test" does what a real event would do, so it changes the
content of /dev; that's expected and intentional.

Kay