rfc: udev should be able to re-exec itself

All,

currently udev does not have a way to restart itself. This would be a useful feature, because we could then use this command when we upgrade or downgrade udev on user's systems so that the most current version of udev is always running.

One of gentoo's developers did suggest a patch quite a while back, but some how it got lost in the shuffel. This patch will not apply now, but it gives the impression that something like this could be added very easily [1].

Thoughts anyone?

Thanks,

William

[1] https://bugs.gentoo.org/show_bug.cgi?id=129204#c7

We do not want daemons to re-execute themselves. It's far more complicated than usually expected, and in most cases it should be avoided.

The problem of interruption-free upgrades is in most cases solved with systemd's socket activation. But I don't think any distribution uses that possibility when they upgrade udev today, but they easily could, all the things are there to make it work.

Udev should not re-execute itself, but stopped, installed, and restarted. If you want fancy upgrade setups, use an init system that supports that properly while keeping things simple, and which allows interruption-free restarts by keeping the sockets open.

Don't hack up daemons with half-baken things; it's *really* hard to get right.

Thanks,
Kay