Subject: Re: [PATCH 0/4][RFC] netns: sysfs: add a netns suffix to net device sysfs entries

From: "Serge E. Hallyn" <[email-masked]>
Date: Wed, 22 Oct 2008 15:30:45 -0500

Quoting Eric W. Biederman ([email-masked]):
> Benjamin Thery <[email-masked]> writes:
> 
> > Support for network namespaces in mainline is pretty complete for
> > some time now, but there is still this issue with sysfs that prevents 
> > more people to use it easily.
> 
> Ben your patchset is completely inappropriate.
> 
> Temporarily adding elements to the ABI that we intend to remove
> is not a proper solution to this problem.
> 
> That user space visible ida you add is a namespace identifier that breaks
> nested containers and migration.  It is very very very wrong.

I disagree (not surprising :) completely.  The well-known userspace
tools (ifconfig, ip, etc) will not see the lo@1, they'll see lo.
Userspace in a container can either umount /sys completely, or do

	mount -t tmpfs none /sys/class/net
	mount --bind /sys/devices/virtual/net/lo@1 /sys/class/net/lo

if they really want to, in which case only their view
of /sys/devices/virtual/net would be different.

Eric, would you hate this less if it was under some

	CONFIG_SYSFS_NETNS_HACK

config variable?

-serge