From: Mahesh Bandewar <[email protected]>
Date: Tue, 18 Aug 2020 17:51:23 -0700
> The sysctl that was added earlier by commit 79134e6ce2c ("net: do
> not create fallback tunnels for non-default namespaces") to create
> fall-back only in root-ns. This patch enhances that behavior to provide
> option not to create fallback tunnels in root-ns as well. Since modules
> that create fallback tunnels could be built-in and setting the sysctl
> value after booting is pointless, so added a config option which defaults
> to zero (to preserve backward compatibility) but also takes values "1" and
> "2" which don't create fallback tunnels in non-root namespaces
> only and no-where respectively.
>
> Signed-off-by: Mahesh Bandewar <[email protected]>
...
> +config SYSCTL_FB_TUNNEL
...
> -int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0;
> +int sysctl_fb_tunnels_only_for_init_net __read_mostly =
> CONFIG_SYSCTL_FB_TUNNEL;
I can't allow this. This requires a kernel rebuild when none is
really necessary. You're also forcing distributions to make a choice
they have no place making at all.
You have two ways to handle this situation already:
1) Kernel command line
2) initrd
I'm not allowing to add a third. And if I had, then that sets
precedence and others will want to do this as well for their
favorite sysctl that has implications as soon as modules get
loaded.