tunnels: add _rcu annotations

[net-next-2.6.git] / net / ipv6 / tunnel6.c

diff --git a/net/ipv6/tunnel6.c b/net/ipv6/tunnel6.c
index d203e6df1f8b3eeaa1b3e3caa0832c92174784c9..4f3cec12aa8575a860f18124f0f4ee7f83cf540d 100644 (file)
--- a/net/ipv6/tunnel6.c
+++ b/net/ipv6/tunnel6.c
@@ -30,28 +30,31 @@
 #include <net/protocol.h>
 #include <net/xfrm.h>
 
-static struct xfrm6_tunnel *tunnel6_handlers __read_mostly;
-static struct xfrm6_tunnel *tunnel46_handlers __read_mostly;
+static struct xfrm6_tunnel __rcu *tunnel6_handlers __read_mostly;
+static struct xfrm6_tunnel __rcu *tunnel46_handlers __read_mostly;
 static DEFINE_MUTEX(tunnel6_mutex);
 
 int xfrm6_tunnel_register(struct xfrm6_tunnel *handler, unsigned short family)
 {
-       struct xfrm6_tunnel **pprev;
+       struct xfrm6_tunnel __rcu **pprev;
+       struct xfrm6_tunnel *t;
        int ret = -EEXIST;
        int priority = handler->priority;
 
        mutex_lock(&tunnel6_mutex);
 
        for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
-            *pprev; pprev = &(*pprev)->next) {
-               if ((*pprev)->priority > priority)
+            (t = rcu_dereference_protected(*pprev,
+                       lockdep_is_held(&tunnel6_mutex))) != NULL;
+            pprev = &t->next) {
+               if (t->priority > priority)
                        break;
-               if ((*pprev)->priority == priority)
+               if (t->priority == priority)
                        goto err;
        }
 
        handler->next = *pprev;
-       *pprev = handler;
+       rcu_assign_pointer(*pprev, handler);
 
        ret = 0;
 
@@ -65,14 +68,17 @@ EXPORT_SYMBOL(xfrm6_tunnel_register);
 
 int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
 {
-       struct xfrm6_tunnel **pprev;
+       struct xfrm6_tunnel __rcu **pprev;
+       struct xfrm6_tunnel *t;
        int ret = -ENOENT;
 
        mutex_lock(&tunnel6_mutex);
 
        for (pprev = (family == AF_INET6) ? &tunnel6_handlers : &tunnel46_handlers;
-            *pprev; pprev = &(*pprev)->next) {
-               if (*pprev == handler) {
+            (t = rcu_dereference_protected(*pprev,
+                       lockdep_is_held(&tunnel6_mutex))) != NULL;
+            pprev = &t->next) {
+               if (t == handler) {
                        *pprev = handler->next;
                        ret = 0;
                        break;
@@ -88,6 +94,11 @@ int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler, unsigned short family)
 
 EXPORT_SYMBOL(xfrm6_tunnel_deregister);
 
+#define for_each_tunnel_rcu(head, handler)             \
+       for (handler = rcu_dereference(head);           \
+            handler != NULL;                           \
+            handler = rcu_dereference(handler->next))  \
+
 static int tunnel6_rcv(struct sk_buff *skb)
 {
        struct xfrm6_tunnel *handler;
@@ -95,7 +106,7 @@ static int tunnel6_rcv(struct sk_buff *skb)
        if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
                goto drop;
 
-       for (handler = tunnel6_handlers; handler; handler = handler->next)
+       for_each_tunnel_rcu(tunnel6_handlers, handler)
                if (!handler->handler(skb))
                        return 0;
 
@@ -113,7 +124,7 @@ static int tunnel46_rcv(struct sk_buff *skb)
        if (!pskb_may_pull(skb, sizeof(struct iphdr)))
                goto drop;
 
-       for (handler = tunnel46_handlers; handler; handler = handler->next)
+       for_each_tunnel_rcu(tunnel46_handlers, handler)
                if (!handler->handler(skb))
                        return 0;
 
@@ -129,7 +140,7 @@ static void tunnel6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 {
        struct xfrm6_tunnel *handler;
 
-       for (handler = tunnel6_handlers; handler; handler = handler->next)
+       for_each_tunnel_rcu(tunnel6_handlers, handler)
                if (!handler->err_handler(skb, opt, type, code, offset, info))
                        break;
 }