net: move bsockets outside of read only beginning of struct inet_hash…

…info

And switch bsockets to atomic_t since it might be changed in parallel.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inet_hashtables.h

@@ -134,7 +134,7 @@ struct inet_hashinfo {
 	struct inet_bind_hashbucket	*bhash;
 
 	unsigned int			bhash_size;
-	int				bsockets;
+	/* 4 bytes hole on 64 bit */
 
 	struct kmem_cache		*bind_bucket_cachep;
 
@@ -151,6 +151,7 @@ struct inet_hashinfo {
 	struct inet_listen_hashbucket	listening_hash[INET_LHTABLE_SIZE]
 					____cacheline_aligned_in_smp;
 
+	atomic_t			bsockets;
 };
 
 static inline struct inet_ehash_bucket *inet_ehash_bucket(

net/ipv4/inet_connection_sock.c

@@ -119,7 +119,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
 					    (tb->num_owners < smallest_size || smallest_size == -1)) {
 						smallest_size = tb->num_owners;
 						smallest_rover = rover;
-						if (hashinfo->bsockets > (high - low) + 1) {
+						if (atomic_read(&hashinfo->bsockets) > (high - low) + 1) {
 							spin_unlock(&head->lock);
 							snum = smallest_rover;
 							goto have_snum;

net/ipv4/inet_hashtables.c

@@ -62,7 +62,7 @@ void inet_bind_hash(struct sock *sk, struct inet_bind_bucket *tb,
 {
 	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 
-	hashinfo->bsockets++;
+	atomic_inc(&hashinfo->bsockets);
 
 	inet_sk(sk)->num = snum;
 	sk_add_bind_node(sk, &tb->owners);
@@ -81,7 +81,7 @@ static void __inet_put_port(struct sock *sk)
 	struct inet_bind_hashbucket *head = &hashinfo->bhash[bhash];
 	struct inet_bind_bucket *tb;
 
-	hashinfo->bsockets--;
+	atomic_dec(&hashinfo->bsockets);
 
 	spin_lock(&head->lock);
 	tb = inet_csk(sk)->icsk_bind_hash;
@@ -532,6 +532,7 @@ void inet_hashinfo_init(struct inet_hashinfo *h)
 {
 	int i;
 
+	atomic_set(&h->bsockets, 0);
 	for (i = 0; i < INET_LHTABLE_SIZE; i++) {
 		spin_lock_init(&h->listening_hash[i].lock);
 		INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].head,