net: move bsockets outside of read only beginning of struct inet_hashinfo

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>

3 files changed, 6 insertions, 4 deletions

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 8d98dc76bd76..a44e2248b2ef 100644
--- a/include/net/inet_hashtables.h
+++ b/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(
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 9bc6a187bdce..22cd19ee44e5 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -119,7 +119,7 @@ again:
                                             (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;
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index d7b6178bf48b..625cc5f64c94 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/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,