[PATCH 1/4] net: Tag the network flow with the network namespace it is in (v2)

As well as marking flows this indirectly marks the ipv4 routing cache
as every routing entry contains a flow.

It is useful to add the network namespace into flows as frequently
the routing information for ingoing and outgoing network packets is
collected into a flow structure which is then used for several functions
as it sorts out what is going on.

Changes from v1:
- remove flow.h dependency from net_namespace.h

Signed-off-by: Denis V. Lunev <redacted>
Signed-off-by: Eric W. Biederman <redacted>
---
 include/net/flow.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/net/flow.h b/include/net/flow.h
index af59fa5..9590bbe 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h

@@ -10,7 +10,9 @@
 #include <linux/in6.h>
 #include <asm/atomic.h>
 
+struct net;
 struct flowi {
+	struct net *fl_net;
 	int	oif;
 	int	iif;
 	__u32	mark;

-- 
1.5.3.rc5