[NETNS][FRAGS]: Make the LRU list per namespace.

The inet_frags.lru_list is used for evicting only, so we have
to make it per-namespace, to evict only those fragments, who's
namespace exceeded its high threshold, but not the whole hash.
Besides, this helps to avoid long loops  in evictor.

The spinlock is not per-namespace because it protects the
hash table as well, which is global.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 1917fbe..3695ff4 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -4,6 +4,7 @@
 struct netns_frags {
 	int			nqueues;
 	atomic_t		mem;
+	struct list_head	lru_list;
 
 	/* sysctls */
 	int			timeout;
@@ -32,7 +33,6 @@
 #define INETFRAGS_HASHSZ		64
 
 struct inet_frags {
-	struct list_head	lru_list;
 	struct hlist_head	hash[INETFRAGS_HASHSZ];
 	rwlock_t		lock;
 	u32			rnd;