[PATCH 2/6][INET]: Consolidate inet(6)_hash_connect.

[Pavel Emelyanov <xemul@openvz.org>]

These two functions are the same except for what they call
to "check_established" and "hash" for a socket.

This saves half-a-kilo for ipv4 and ipv6.

 add/remove: 1/0 grow/shrink: 1/4 up/down: 582/-1128 (-546)
 function                                     old     new   delta
 __inet_hash_connect                            -     577    +577
 arp_ignore                                   108     113      +5
 static.hint                                    8       4      -4
 rt_worker_func                               376     372      -4
 inet6_hash_connect                           584      25    -559
 inet_hash_connect                            586      25    -561

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---
 include/net/inet_hashtables.h |    5 ++
 net/ipv4/inet_hashtables.c    |   32 +++++++++-----
 net/ipv6/inet6_hashtables.c   |   93 +----------------------------------------
 3 files changed, 28 insertions(+), 102 deletions(-)

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 761bdc0..a34a8f2 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -413,6 +413,11 @@ static inline struct sock *inet_lookup(struct inet_hashinfo *hashinfo,
 	return sk;
 }
 
+extern int __inet_hash_connect(struct inet_timewait_death_row *death_row,
+		struct sock *sk,
+		int (*check_established)(struct inet_timewait_death_row *,
+			struct sock *, __u16, struct inet_timewait_sock **),
+		void (*hash)(struct inet_hashinfo *, struct sock *));
 extern int inet_hash_connect(struct inet_timewait_death_row *death_row,
 			     struct sock *sk);
 #endif /* _INET_HASHTABLES_H */
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 619c63c..b93d40f 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -348,11 +348,11 @@ void __inet_hash(struct inet_hashinfo *hashinfo, struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(__inet_hash);
 
-/*
- * Bind a port for a connect operation and hash it.
- */
-int inet_hash_connect(struct inet_timewait_death_row *death_row,
-		      struct sock *sk)
+int __inet_hash_connect(struct inet_timewait_death_row *death_row,
+		struct sock *sk,
+		int (*check_established)(struct inet_timewait_death_row *,
+			struct sock *, __u16, struct inet_timewait_sock **),
+		void (*hash)(struct inet_hashinfo *, struct sock *))
 {
 	struct inet_hashinfo *hinfo = death_row->hashinfo;
 	const unsigned short snum = inet_sk(sk)->num;
@@ -385,9 +385,8 @@ int inet_hash_connect(struct inet_timewait_death_row *death_row,
 					BUG_TRAP(!hlist_empty(&tb->owners));
 					if (tb->fastreuse >= 0)
 						goto next_port;
-					if (!__inet_check_established(death_row,
-								      sk, port,
-								      &tw))
+					if (!check_established(death_row, sk,
+								port, &tw))
 						goto ok;
 					goto next_port;
 				}
@@ -415,7 +414,7 @@ ok:
 		inet_bind_hash(sk, tb, port);
 		if (sk_unhashed(sk)) {
 			inet_sk(sk)->sport = htons(port);
-			__inet_hash_nolisten(hinfo, sk);
+			hash(hinfo, sk);
 		}
 		spin_unlock(&head->lock);
 
@@ -432,17 +431,28 @@ ok:
 	tb  = inet_csk(sk)->icsk_bind_hash;
 	spin_lock_bh(&head->lock);
 	if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
-		__inet_hash_nolisten(hinfo, sk);
+		hash(hinfo, sk);
 		spin_unlock_bh(&head->lock);
 		return 0;
 	} else {
 		spin_unlock(&head->lock);
 		/* No definite answer... Walk to established hash table */
-		ret = __inet_check_established(death_row, sk, snum, NULL);
+		ret = check_established(death_row, sk, snum, NULL);
 out:
 		local_bh_enable();
 		return ret;
 	}
 }
+EXPORT_SYMBOL_GPL(__inet_hash_connect);
+
+/*
+ * Bind a port for a connect operation and hash it.
+ */
+int inet_hash_connect(struct inet_timewait_death_row *death_row,
+		      struct sock *sk)
+{
+	return __inet_hash_connect(death_row, sk,
+			__inet_check_established, __inet_hash_nolisten);
+}
 
 EXPORT_SYMBOL_GPL(inet_hash_connect);
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 06b01be..ece6d0e 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -233,97 +233,8 @@ static inline u32 inet6_sk_port_offset(const struct sock *sk)
 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 		       struct sock *sk)
 {
-	struct inet_hashinfo *hinfo = death_row->hashinfo;
-	const unsigned short snum = inet_sk(sk)->num;
-	struct inet_bind_hashbucket *head;
-	struct inet_bind_bucket *tb;
-	int ret;
-
-	if (snum == 0) {
-		int i, port, low, high, remaining;
-		static u32 hint;
-		const u32 offset = hint + inet6_sk_port_offset(sk);
-		struct hlist_node *node;
-		struct inet_timewait_sock *tw = NULL;
-
-		inet_get_local_port_range(&low, &high);
-		remaining = (high - low) + 1;
-
-		local_bh_disable();
-		for (i = 1; i <= remaining; i++) {
-			port = low + (i + offset) % remaining;
-			head = &hinfo->bhash[inet_bhashfn(port, hinfo->bhash_size)];
-			spin_lock(&head->lock);
-
-			/* Does not bother with rcv_saddr checks,
-			 * because the established check is already
-			 * unique enough.
-			 */
-			inet_bind_bucket_for_each(tb, node, &head->chain) {
-				if (tb->port == port) {
-					BUG_TRAP(!hlist_empty(&tb->owners));
-					if (tb->fastreuse >= 0)
-						goto next_port;
-					if (!__inet6_check_established(death_row,
-								       sk, port,
-								       &tw))
-						goto ok;
-					goto next_port;
-				}
-			}
-
-			tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
-						     head, port);
-			if (!tb) {
-				spin_unlock(&head->lock);
-				break;
-			}
-			tb->fastreuse = -1;
-			goto ok;
-
-		next_port:
-			spin_unlock(&head->lock);
-		}
-		local_bh_enable();
-
-		return -EADDRNOTAVAIL;
-
-ok:
-		hint += i;
-
-		/* Head lock still held and bh's disabled */
-		inet_bind_hash(sk, tb, port);
-		if (sk_unhashed(sk)) {
-			inet_sk(sk)->sport = htons(port);
-			__inet6_hash(hinfo, sk);
-		}
-		spin_unlock(&head->lock);
-
-		if (tw) {
-			inet_twsk_deschedule(tw, death_row);
-			inet_twsk_put(tw);
-		}
-
-		ret = 0;
-		goto out;
-	}
-
-	head = &hinfo->bhash[inet_bhashfn(snum, hinfo->bhash_size)];
-	tb   = inet_csk(sk)->icsk_bind_hash;
-	spin_lock_bh(&head->lock);
-
-	if (sk_head(&tb->owners) == sk && sk->sk_bind_node.next == NULL) {
-		__inet6_hash(hinfo, sk);
-		spin_unlock_bh(&head->lock);
-		return 0;
-	} else {
-		spin_unlock(&head->lock);
-		/* No definite answer... Walk to established hash table */
-		ret = __inet6_check_established(death_row, sk, snum, NULL);
-out:
-		local_bh_enable();
-		return ret;
-	}
+	return __inet_hash_connect(death_row, sk,
+			__inet6_check_established, __inet6_hash);
 }
 
 EXPORT_SYMBOL_GPL(inet6_hash_connect);
-- 
1.5.3.4