[INET]: Collect frag queues management objects together

There are some objects that are common in all the places
which are used to keep track of frag queues, they are:

 * hash table
 * LRU list
 * rw lock
 * rnd number for hash function
 * the number of queues
 * the amount of memory occupied by queues
 * secret timer

Move all this stuff into one structure (struct inet_frags)
to make it possible use them uniformly in the future. Like
with the previous patch this mostly consists of hunks like

-    write_lock(&ipfrag_lock);
+    write_lock(&ip4_frags.lock);

To address the issue with exporting the number of queues and
the amount of memory occupied by queues outside the .c file
they are declared in, I introduce a couple of helpers.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 74e9cb9..d51f238 100644
--- a/include/net/inet_frag.h
+++ b/include/net/inet_frag.h
@@ -18,4 +18,19 @@ struct inet_frag_queue {
 #define LAST_IN			1
 };
 
+#define INETFRAGS_HASHSZ		64
+
+struct inet_frags {
+	struct list_head	lru_list;
+	struct hlist_head	hash[INETFRAGS_HASHSZ];
+	rwlock_t		lock;
+	u32			rnd;
+	int			nqueues;
+	atomic_t		mem;
+	struct timer_list	secret_timer;
+};
+
+void inet_frags_init(struct inet_frags *);
+void inet_frags_fini(struct inet_frags *);
+
 #endif