[IPV6]: Remove ndiscs rt6_lock dependency

(Ab)using rt6_lock wouldn't work anymore if rt6_lock is
converted into a per table lock.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 5 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d9baca062d24..ce1f49b595b0 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -747,8 +747,6 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
         }
 }
 
-/* Protected by rt6_lock.  */
-static struct dst_entry *ndisc_dst_gc_list;
 static int ipv6_get_mtu(struct net_device *dev);
 
 static inline unsigned int ipv6_advmss(unsigned int mtu)
@@ -769,6 +767,9 @@ static inline unsigned int ipv6_advmss(unsigned int mtu)
         return mtu;
 }
 
+static struct dst_entry *ndisc_dst_gc_list;
+DEFINE_SPINLOCK(ndisc_lock);
+
 struct dst_entry *ndisc_dst_alloc(struct net_device *dev, 
                                   struct neighbour *neigh,
                                   struct in6_addr *addr,
@@ -809,10 +810,10 @@ struct dst_entry *ndisc_dst_alloc(struct net_device *dev,
         rt->rt6i_dst.plen = 128;
 #endif
 
-        write_lock_bh(&rt6_lock);
+        spin_lock_bh(&ndisc_lock);
         rt->u.dst.next = ndisc_dst_gc_list;
         ndisc_dst_gc_list = &rt->u.dst;
-        write_unlock_bh(&rt6_lock);
+        spin_unlock_bh(&ndisc_lock);
 
         fib6_force_start_gc();
 
@@ -826,8 +827,11 @@ int ndisc_dst_gc(int *more)
         int freed;
 
         next = NULL;
+        freed = 0;
+
+        spin_lock_bh(&ndisc_lock);
         pprev = &ndisc_dst_gc_list;
-        freed = 0;
+
         while ((dst = *pprev) != NULL) {
                 if (!atomic_read(&dst->__refcnt)) {
                         *pprev = dst->next;
@@ -839,6 +843,8 @@ int ndisc_dst_gc(int *more)
                 }
         }
 
+        spin_unlock_bh(&ndisc_lock);
+
         return freed;
 }