Re: [PATCH] sysfs: Don't allow the creation of symlinks we can't remove

[Johannes Berg <johannes@sipsolutions.net>]

On Thu, 2010-07-22 at 04:27 -0700, Eric W. Biederman wrote:

> >> Do we have a convenient command line tool to do this?
> >> I remember there being a different netlink message from
> >> normal network devices.
> >
> > iw phy0 set netns <pid>
> >
> > http://git.sipsolutions.net/iw.git
> >
> >> > root@kvm:~# ip link
> >> > 3: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
> >> >     link/ether 02:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
> >> > 7: lo: <LOOPBACK> mtu 16436 qdisc noop state DOWN 
> >> >     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
> >> > root@kvm:~# ls /sys/class/net/
> >> > eth0  hwsim0  lo  wlan1  wlan2
> >> 
> >> I think this is actually the output of something working.
> >> 
> >> I expect after you created a new netns you didn't mount
> >> a new instance of /sys.  /sys remembers which netns you
> >> had when you mounted it.  So you have to mount /sys again
> >> so you can see the /sys/class/net for the network namespace
> >> you are in.
> >
> > Ohh, oops! I saw all the "current->" references in the code and somehow
> > expected the same instance of sysfs to show the right thing.
> >
> > Yes, it works now. But the patch below doesn't seem to work, am I
> > missing something?
> 
> You are trying to move the phy devices as well?

Yes. The intent is that each wireless phy lives in a netns along with
all of its child devices.

> My guess is that at least part of the problem is that you don't have a
> ieee80211 directory under hwsim.

But I should have? 'ieee80211' is a class just like 'net', no?

> My apologies for not thinking about the peculiarities of the wireless
> drivers.

No worries.

johannes