net: ib_net pointer should depends on CONFIG_NET_NS

We can shrink size of "struct inet_bind_bucket" by 50%, using
read_pnet() and write_pnet()

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

3 files changed, 12 insertions, 5 deletions

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 5cc182f9ecae..cb31fbf8ae2a 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -77,13 +77,20 @@ struct inet_ehash_bucket {
  * ports are created in O(1) time?  I thought so. ;-)   -DaveM
  */
 struct inet_bind_bucket {
+#ifdef CONFIG_NET_NS
         struct net              *ib_net;
+#endif
         unsigned short          port;
         signed short            fastreuse;
         struct hlist_node       node;
         struct hlist_head       owners;
 };
 
+static inline struct net *ib_net(struct inet_bind_bucket *ib)
+{
+        return read_pnet(&ib->ib_net);
+}
+
 #define inet_bind_bucket_for_each(tb, node, head) \
         hlist_for_each_entry(tb, node, head, node)
 
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 36f4cbc7da3a..05af807ca9b9 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -109,7 +109,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
                                         hashinfo->bhash_size)];
                         spin_lock(&head->lock);
                         inet_bind_bucket_for_each(tb, node, &head->chain)
-                                if (tb->ib_net == net && tb->port == rover)
+                                if (ib_net(tb) == net && tb->port == rover)
                                         goto next;
                         break;
                 next:
@@ -137,7 +137,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum)
                                 hashinfo->bhash_size)];
                 spin_lock(&head->lock);
                 inet_bind_bucket_for_each(tb, node, &head->chain)
-                        if (tb->ib_net == net && tb->port == snum)
+                        if (ib_net(tb) == net && tb->port == snum)
                                 goto tb_found;
         }
         tb = NULL;
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 44981906fb91..be41ebbec4eb 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -35,7 +35,7 @@ struct inet_bind_bucket *inet_bind_bucket_create(struct kmem_cache *cachep,
         struct inet_bind_bucket *tb = kmem_cache_alloc(cachep, GFP_ATOMIC);
 
         if (tb != NULL) {
-                tb->ib_net       = hold_net(net);
+                write_pnet(&tb->ib_net, hold_net(net));
                 tb->port      = snum;
                 tb->fastreuse = 0;
                 INIT_HLIST_HEAD(&tb->owners);
@@ -51,7 +51,7 @@ void inet_bind_bucket_destroy(struct kmem_cache *cachep, struct inet_bind_bucket
 {
         if (hlist_empty(&tb->owners)) {
                 __hlist_del(&tb->node);
-                release_net(tb->ib_net);
+                release_net(ib_net(tb));
                 kmem_cache_free(cachep, tb);
         }
 }
@@ -449,7 +449,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
                          * unique enough.
                          */
                         inet_bind_bucket_for_each(tb, node, &head->chain) {
-                                if (tb->ib_net == net && tb->port == port) {
+                                if (ib_net(tb) == net && tb->port == port) {
                                         WARN_ON(hlist_empty(&tb->owners));
                                         if (tb->fastreuse >= 0)
                                                 goto next_port;