[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>

3 files changed, 19 insertions, 4 deletions

diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h
index 74e9cb9b6943..d51f23873da9 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
diff --git a/include/net/ip.h b/include/net/ip.h
index 875c5ed53343..c08c59e2384c 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -333,8 +333,8 @@ enum ip_defrag_users
 };
 
 int ip_defrag(struct sk_buff *skb, u32 user);
-extern int ip_frag_nqueues;
-extern atomic_t ip_frag_mem;
+int ip_frag_mem(void);
+int ip_frag_nqueues(void);
 
 /*
  *      Functions provided by ip_forward.c
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 31b3f1b45a2b..77cdab3ce160 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -252,8 +252,8 @@ struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
 
 extern int ipv6_opt_accepted(struct sock *sk, struct sk_buff *skb);
 
-extern int ip6_frag_nqueues;
-extern atomic_t ip6_frag_mem;
+int ip6_frag_nqueues(void);
+int ip6_frag_mem(void);
 
 #define IPV6_FRAG_TIMEOUT       (60*HZ)         /* 60 seconds */