Based on a patch by Kay Sievers.
A tag is exported at boot as a symlinks to the device node in the folder
/run/udev/static_node-tags/<tagname>/, if the device node exists.
These tags are cleaned up by udevadm info --cleanup-db, but are otherwise
never removed.
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.
Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.
The bits that used to be MIT continue to be MIT.
The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.
Tom Gundersen
Kay Sievers
Lennart Poettering
Kay Sievers