[IPV4]: Prepare FIB core for RCU.

* RCU versions of hlist_***_rcu
* fib_alias partial rcu port just whats needed now.

Signed-off-by: Robert Olsson <Robert.Olsson@data.slu.se>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 0 deletions

diff --git a/include/linux/list.h b/include/linux/list.h
index 0f2435f92db3..9b9b0eec1e8a 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -634,6 +634,27 @@ static inline void hlist_add_after(struct hlist_node *n,
                 next->next->pprev  = &next->next;
 }
 
+static inline void hlist_add_before_rcu(struct hlist_node *n,
+                                        struct hlist_node *next)
+{
+        n->pprev = next->pprev;
+        n->next = next;
+        smp_wmb();
+        next->pprev = &n->next;
+        *(n->pprev) = n;
+}
+
+static inline void hlist_add_after_rcu(struct hlist_node *prev,
+                                       struct hlist_node *n)
+{
+        n->next = prev->next;
+        n->pprev = &prev->next;
+        smp_wmb();
+        prev->next = n;
+        if (n->next)
+                n->next->pprev = &n->next;
+}
+
 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
 
 #define hlist_for_each(pos, head) \