ip6mr: do not acquire mrt_lock while calling ip6_mr_forward()

ip6_mr_forward() uses standard RCU protection already.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 089c26a..8a751a3 100644 (file)
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -2042,9 +2042,7 @@ static int ip6mr_forward2(struct net *net, struct mr_table *mrt,
                WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
                vif_dev->stats.tx_bytes += skb->len;
                vif_dev->stats.tx_packets++;
-               rcu_read_lock();
                ip6mr_cache_report(mrt, skb, vifi, MRT6MSG_WHOLEPKT);
-               rcu_read_unlock();
                goto out_free;
        }
 #endif
@@ -2112,6 +2110,7 @@ static int ip6mr_find_vif(struct mr_table *mrt, struct net_device *dev)
        return ct;
 }
 
+/* Called under rcu_read_lock() */
 static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
                           struct net_device *dev, struct sk_buff *skb,
                           struct mfc6_cache *c)
@@ -2131,14 +2130,12 @@ static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
                /* For an (*,G) entry, we only check that the incoming
                 * interface is part of the static tree.
                 */
-               rcu_read_lock();
                cache_proxy = mr_mfc_find_any_parent(mrt, vif);
                if (cache_proxy &&
                    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255) {
                        rcu_read_unlock();
                        goto forward;
                }
-               rcu_read_unlock();
        }
 
        /*
@@ -2159,12 +2156,10 @@ static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
                               c->_c.mfc_un.res.last_assert +
                               MFC_ASSERT_THRESH)) {
                        c->_c.mfc_un.res.last_assert = jiffies;
-                       rcu_read_lock();
                        ip6mr_cache_report(mrt, skb, true_vifi, MRT6MSG_WRONGMIF);
                        if (mrt->mroute_do_wrvifwhole)
                                ip6mr_cache_report(mrt, skb, true_vifi,
                                                   MRT6MSG_WRMIFWHOLE);
-                       rcu_read_unlock();
                }
                goto dont_forward;
        }
@@ -2278,11 +2273,8 @@ int ip6_mr_input(struct sk_buff *skb)
                return -ENODEV;
        }
 
-       read_lock(&mrt_lock);
        ip6_mr_forward(net, mrt, dev, skb, cache);
 
-       read_unlock(&mrt_lock);
-
        return 0;
 }