1 files changed, 45 insertions, 48 deletions

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index c595bbe1ed99..d453d07b0dfe 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -78,7 +78,7 @@ static void ip6_fb_tnl_dev_init(struct net_device *dev);
 static void ip6_tnl_dev_init(struct net_device *dev);
 static void ip6_tnl_dev_setup(struct net_device *dev);
 
-static int ip6_tnl_net_id;
+static int ip6_tnl_net_id __read_mostly;
 struct ip6_tnl_net {
         /* the IPv6 tunnel fallback device */
         struct net_device *fb_tnl_dev;
@@ -88,8 +88,10 @@ struct ip6_tnl_net {
         struct ip6_tnl **tnls[2];
 };
 
-/* lock for the tunnel lists */
-static DEFINE_RWLOCK(ip6_tnl_lock);
+/*
+ * Locking : hash tables are protected by RCU and a spinlock
+ */
+static DEFINE_SPINLOCK(ip6_tnl_lock);
 
 static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
 {
@@ -130,6 +132,9 @@ static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
  *   else %NULL
  **/
 
+#define for_each_ip6_tunnel_rcu(start) \
+        for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
+
 static struct ip6_tnl *
 ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local)
 {
@@ -138,13 +143,14 @@ ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local)
         struct ip6_tnl *t;
         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 
-        for (t = ip6n->tnls_r_l[h0 ^ h1]; t; t = t->next) {
+        for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[h0 ^ h1]) {
                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
                     ipv6_addr_equal(remote, &t->parms.raddr) &&
                     (t->dev->flags & IFF_UP))
                         return t;
         }
-        if ((t = ip6n->tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP))
+        t = rcu_dereference(ip6n->tnls_wc[0]);
+        if (t && (t->dev->flags & IFF_UP))
                 return t;
 
         return NULL;
@@ -186,10 +192,10 @@ ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 {
         struct ip6_tnl **tp = ip6_tnl_bucket(ip6n, &t->parms);
 
+        spin_lock_bh(&ip6_tnl_lock);
         t->next = *tp;
-        write_lock_bh(&ip6_tnl_lock);
-        *tp = t;
-        write_unlock_bh(&ip6_tnl_lock);
+        rcu_assign_pointer(*tp, t);
+        spin_unlock_bh(&ip6_tnl_lock);
 }
 
 /**
@@ -204,9 +210,9 @@ ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 
         for (tp = ip6_tnl_bucket(ip6n, &t->parms); *tp; tp = &(*tp)->next) {
                 if (t == *tp) {
-                        write_lock_bh(&ip6_tnl_lock);
+                        spin_lock_bh(&ip6_tnl_lock);
                         *tp = t->next;
-                        write_unlock_bh(&ip6_tnl_lock);
+                        spin_unlock_bh(&ip6_tnl_lock);
                         break;
                 }
         }
@@ -313,9 +319,9 @@ ip6_tnl_dev_uninit(struct net_device *dev)
         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 
         if (dev == ip6n->fb_tnl_dev) {
-                write_lock_bh(&ip6_tnl_lock);
+                spin_lock_bh(&ip6_tnl_lock);
                 ip6n->tnls_wc[0] = NULL;
-                write_unlock_bh(&ip6_tnl_lock);
+                spin_unlock_bh(&ip6_tnl_lock);
         } else {
                 ip6_tnl_unlink(ip6n, t);
         }
@@ -409,7 +415,7 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
            in trouble since we might need the source address for further
            processing of the error. */
 
-        read_lock(&ip6_tnl_lock);
+        rcu_read_lock();
         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
                                         &ipv6h->saddr)) == NULL)
                 goto out;
@@ -482,7 +488,7 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
         *msg = rel_msg;
 
 out:
-        read_unlock(&ip6_tnl_lock);
+        rcu_read_unlock();
         return err;
 }
 
@@ -652,6 +658,7 @@ static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
                 IP6_ECN_set_ce(ipv6_hdr(skb));
 }
 
+/* called with rcu_read_lock() */
 static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t)
 {
         struct ip6_tnl_parm *p = &t->parms;
@@ -662,15 +669,13 @@ static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t)
                 struct net_device *ldev = NULL;
 
                 if (p->link)
-                        ldev = dev_get_by_index(net, p->link);
+                        ldev = dev_get_by_index_rcu(net, p->link);
 
                 if ((ipv6_addr_is_multicast(&p->laddr) ||
                      likely(ipv6_chk_addr(net, &p->laddr, ldev, 0))) &&
                     likely(!ipv6_chk_addr(net, &p->raddr, NULL, 0)))
                         ret = 1;
 
-                if (ldev)
-                        dev_put(ldev);
         }
         return ret;
 }
@@ -693,23 +698,23 @@ static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
         struct ip6_tnl *t;
         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 
-        read_lock(&ip6_tnl_lock);
+        rcu_read_lock();
 
         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
                                         &ipv6h->daddr)) != NULL) {
                 if (t->parms.proto != ipproto && t->parms.proto != 0) {
-                        read_unlock(&ip6_tnl_lock);
+                        rcu_read_unlock();
                         goto discard;
                 }
 
                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
-                        read_unlock(&ip6_tnl_lock);
+                        rcu_read_unlock();
                         goto discard;
                 }
 
                 if (!ip6_tnl_rcv_ctl(t)) {
                         t->dev->stats.rx_dropped++;
-                        read_unlock(&ip6_tnl_lock);
+                        rcu_read_unlock();
                         goto discard;
                 }
                 secpath_reset(skb);
@@ -727,10 +732,10 @@ static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
                 t->dev->stats.rx_packets++;
                 t->dev->stats.rx_bytes += skb->len;
                 netif_rx(skb);
-                read_unlock(&ip6_tnl_lock);
+                rcu_read_unlock();
                 return 0;
         }
-        read_unlock(&ip6_tnl_lock);
+        rcu_read_unlock();
         return 1;
 
 discard:
@@ -798,8 +803,9 @@ static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
         if (p->flags & IP6_TNL_F_CAP_XMIT) {
                 struct net_device *ldev = NULL;
 
+                rcu_read_lock();
                 if (p->link)
-                        ldev = dev_get_by_index(net, p->link);
+                        ldev = dev_get_by_index_rcu(net, p->link);
 
                 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
                         printk(KERN_WARNING
@@ -813,8 +819,7 @@ static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
                                p->name);
                 else
                         ret = 1;
-                if (ldev)
-                        dev_put(ldev);
+                rcu_read_unlock();
         }
         return ret;
 }
@@ -1387,29 +1392,25 @@ static void ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n)
 {
         int h;
         struct ip6_tnl *t;
+        LIST_HEAD(list);
 
         for (h = 0; h < HASH_SIZE; h++) {
-                while ((t = ip6n->tnls_r_l[h]) != NULL)
-                        unregister_netdevice(t->dev);
+                t = ip6n->tnls_r_l[h];
+                while (t != NULL) {
+                        unregister_netdevice_queue(t->dev, &list);
+                        t = t->next;
+                }
         }
 
         t = ip6n->tnls_wc[0];
-        unregister_netdevice(t->dev);
+        unregister_netdevice_queue(t->dev, &list);
+        unregister_netdevice_many(&list);
 }
 
 static int ip6_tnl_init_net(struct net *net)
 {
+        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
         int err;
-        struct ip6_tnl_net *ip6n;
-
-        err = -ENOMEM;
-        ip6n = kzalloc(sizeof(struct ip6_tnl_net), GFP_KERNEL);
-        if (ip6n == NULL)
-                goto err_alloc;
-
-        err = net_assign_generic(net, ip6_tnl_net_id, ip6n);
-        if (err < 0)
-                goto err_assign;
 
         ip6n->tnls[0] = ip6n->tnls_wc;
         ip6n->tnls[1] = ip6n->tnls_r_l;
@@ -1432,27 +1433,23 @@ static int ip6_tnl_init_net(struct net *net)
 err_register:
         free_netdev(ip6n->fb_tnl_dev);
 err_alloc_dev:
-        /* nothing */
-err_assign:
-        kfree(ip6n);
-err_alloc:
         return err;
 }
 
 static void ip6_tnl_exit_net(struct net *net)
 {
-        struct ip6_tnl_net *ip6n;
+        struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 
-        ip6n = net_generic(net, ip6_tnl_net_id);
         rtnl_lock();
         ip6_tnl_destroy_tunnels(ip6n);
         rtnl_unlock();
-        kfree(ip6n);
 }
 
 static struct pernet_operations ip6_tnl_net_ops = {
         .init = ip6_tnl_init_net,
         .exit = ip6_tnl_exit_net,
+        .id   = &ip6_tnl_net_id,
+        .size = sizeof(struct ip6_tnl_net),
 };
 
 /**
@@ -1477,7 +1474,7 @@ static int __init ip6_tunnel_init(void)
                 goto unreg_ip4ip6;
         }
 
-        err = register_pernet_gen_device(&ip6_tnl_net_id, &ip6_tnl_net_ops);
+        err = register_pernet_device(&ip6_tnl_net_ops);
         if (err < 0)
                 goto err_pernet;
         return 0;
@@ -1501,7 +1498,7 @@ static void __exit ip6_tunnel_cleanup(void)
         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
                 printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n");
 
-        unregister_pernet_gen_device(ip6_tnl_net_id, &ip6_tnl_net_ops);
+        unregister_pernet_device(&ip6_tnl_net_ops);
 }
 
 module_init(ip6_tunnel_init);