ipv6: drop ipv6_sk_mc_lock in mcast

Similarly the code is already protected by rtnl lock.

Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 484a942..27ca0b7 100644 (file)
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -73,9 +73,6 @@ static void *__mld2_query_bugs[] __attribute__((__unused__)) = {
 
 static struct in6_addr mld2_all_mcr = MLD2_ALL_MCR_INIT;
 
-/* Big mc list lock for all the sockets */
-static DEFINE_SPINLOCK(ipv6_sk_mc_lock);
-
 static void igmp6_join_group(struct ifmcaddr6 *ma);
 static void igmp6_leave_group(struct ifmcaddr6 *ma);
 static void igmp6_timer_handler(unsigned long data);
@@ -201,10 +198,8 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
                return err;
        }
 
-       spin_lock(&ipv6_sk_mc_lock);
        mc_lst->next = np->ipv6_mc_list;
        rcu_assign_pointer(np->ipv6_mc_list, mc_lst);
-       spin_unlock(&ipv6_sk_mc_lock);
 
        rcu_read_unlock();
        rtnl_unlock();
@@ -226,17 +221,14 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
                return -EINVAL;
 
        rtnl_lock();
-       spin_lock(&ipv6_sk_mc_lock);
        for (lnk = &np->ipv6_mc_list;
-            (mc_lst = rcu_dereference_protected(*lnk,
-                       lockdep_is_held(&ipv6_sk_mc_lock))) != NULL;
+            (mc_lst = rtnl_dereference(*lnk)) != NULL;
              lnk = &mc_lst->next) {
                if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
                    ipv6_addr_equal(&mc_lst->addr, addr)) {
                        struct net_device *dev;
 
                        *lnk = mc_lst->next;
-                       spin_unlock(&ipv6_sk_mc_lock);
 
                        rcu_read_lock();
                        dev = dev_get_by_index_rcu(net, mc_lst->ifindex);
@@ -256,7 +248,6 @@ int ipv6_sock_mc_drop(struct sock *sk, int ifindex, const struct in6_addr *addr)
                        return 0;
                }
        }
-       spin_unlock(&ipv6_sk_mc_lock);
        rtnl_unlock();
 
        return -EADDRNOTAVAIL;
@@ -303,13 +294,10 @@ void ipv6_sock_mc_close(struct sock *sk)
                return;
 
        rtnl_lock();
-       spin_lock(&ipv6_sk_mc_lock);
-       while ((mc_lst = rcu_dereference_protected(np->ipv6_mc_list,
-                               lockdep_is_held(&ipv6_sk_mc_lock))) != NULL) {
+       while ((mc_lst = rtnl_dereference(np->ipv6_mc_list)) != NULL) {
                struct net_device *dev;
 
                np->ipv6_mc_list = mc_lst->next;
-               spin_unlock(&ipv6_sk_mc_lock);
 
                rcu_read_lock();
                dev = dev_get_by_index_rcu(net, mc_lst->ifindex);
@@ -326,9 +314,7 @@ void ipv6_sock_mc_close(struct sock *sk)
                atomic_sub(sizeof(*mc_lst), &sk->sk_omem_alloc);
                kfree_rcu(mc_lst, rcu);
 
-               spin_lock(&ipv6_sk_mc_lock);
        }
-       spin_unlock(&ipv6_sk_mc_lock);
        rtnl_unlock();
 }