netns: Deduplicate and fix copy_net_ns when !CONFIG_NET_NS

The copy of copy_net_ns used when the network stack is not
built is broken as it does not return -EINVAL when attempting
to create a new network namespace.  We don't even have
a previous network namespace.

Since we need a copy of copy_net_ns in net/net_namespace.h that is
available when the networking stack is not built at all move the
correct version of copy_net_ns from net_namespace.c into net_namespace.h
Leaving us with just 2 versions of copy_net_ns.  One version for when
we compile in network namespace suport and another stub for all other
occasions.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 7 deletions

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 42f1e1c7514..2c1c5909168 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -347,13 +347,6 @@ struct net *get_net_ns_by_fd(int fd)
 }
 
 #else
-struct net *copy_net_ns(unsigned long flags, struct net *old_net)
-{
-	if (flags & CLONE_NEWNET)
-		return ERR_PTR(-EINVAL);
-	return old_net;
-}
-
 struct net *get_net_ns_by_fd(int fd)
 {
 	return ERR_PTR(-EINVAL);