[systemd-devel] Udev won't rename interfaces that are already UP

[Lennart Poettering]

On Wed, 18.02.15 18:26, Giancarlo Razzolini (grazzolini at gmail.com) wrote:

> On 18-02-2015 18:12, Mantas Mikulėnas wrote:
> > It's so much not that udev won't do this – the kernel actually won't
> > let it to:
> >
> > # ip link set eth0 up
> > # ip link set eth0 name fred0
> > RTNETLINK answers: Device or resource busy
> > #
> >
> Thank you for your fast response, Mantas. I'm aware that this is a
> kernel limitation. But udev could force the renaming by intentionally
> flushing and/or downing the interface. I know this is a corner case, but
> I believe that the early userspace network configuration should be
> forcibly dropped, no matter what. Also, I know that early userspace
> networking isn't common place, but it has many applications, as those
> hooks show. I'd be happy to give a try in making a patch, but I wanted
> first to get some input from you guys.

Well, if you have networking up so early that's usually because you
need it to boot, for example because it is the backing device for the
root file system. In such a case it would be a really bad idea to take
the network interface down.

I think generally the deal is pretty OK and kinda expected: if you
want early networking, then you have to stick with the name you choose
that early.

I figure if you want control over naming of the interfaces, the right
option would be to include the .link file for it in the initrd image,
so that it is applied that early.

Lennart

-- 
Lennart Poettering, Red Hat