Subject: Re: [PATCH net-next] net: do not create fallback tunnels for non-default namespaces

From: Jiri Benc <[email-masked]>
Date: Fri, 9 Mar 2018 14:08:40 +0100

On Fri, 9 Mar 2018 04:53:07 -0800, Eric Dumazet wrote:
> Unless you bring it up ;)

Often, you need some options to be specified, thus you end up creating
another interface anyway.

> Compatibility problems,  mostly.
> Some users might depend on existing behavior.

How is this a compatibility problem, when the user has to opt in?
Without the default value, the kernel behaves as before. I'm sorry,
I don't see the problem, what am I missing?

> You and me would not care of breaking our setups, but maybe not
> unaware people out there.

Sure, that's why this is an option and it defaults to off.

> Since init_ns is created at boot time before the sysctl can be
> changed, we rather should not change the default behavior for init_ns.

This could be a problem for built in drivers. With modules, I'm
perfectly happy doing this in initrd :-)

To behave consistently in all cases, we might consider adding a boot
option for this, too, though.

 Jiri