Quoting Greg KH (gregkh@suse.de):

On Tue, Apr 29, 2008 at 02:34:17PM -0500, Serge E. Hallyn wrote:

quoted

Finally, to give an idea about how the trees end up looking, here is
what I just did on my test box;

/usr/sbin/ip link add type veth
mount --bind /mnt /mnt
mkdir /mnt/sys
mount --make-shared /mnt
ns_exec -cmn /bin/sh  # unshare netns and mounts ns
 # At this point, I still see eth0 and friends under /sys/class/net etc
mount -t sysfs none /sys
 # At this point, /sys/class/net has only lo0 and sit0, and
 # /sys/devices/pci0000:00/0000:00:03.0/net:eth0 is a dead link
mount --bind /sys /mnt/sys
echo $$
	3050

(back in another shell):
/usr/sbin/ip link set veth1 netns 3050

(back in container shell):
/usr/sbin/ip link set veth1 name eth0
 # Now /sys/devices/pci0000:00/0000:00:03.0/net:eth0 is a live link to
 # the /sys/class/net/eth0 which is really the original veth1
exit

ls /mnt/sys/class/net
 # empty directory

What does this all look like without CONFIG_SYSFS_DEPRECATED enabled,
which is what all sane distros do these days.  That's going to change
the look of the tree for stuff like this a lot I think...

thanks,

greg k-h

Now before moving veth1 to the new netns, we have in the container:
/sys/class/net:
lo  sit0

/sys/devices/virtual/net:
lo  sit0

and after moving veth1, we have in the container:

/sys/class/net:
lo  sit0  veth1

/sys/devices/virtual/net:
lo  sit0

In the parent network namespace, veth1 is removed from /sys/class/net
but remains in /sys/devices/virtual/net.

I'm not sure whether this is the renaming bug that Daniel Lezcano's
patch addresses.  If not (as I suspect) then that clearly needs to be
fixed.

Benjamin can you play around with this and test it with Daniel's
patch?

thanks,
-serge