net/ipv6: Move rcu_read_lock to callers of ip6_rt_cache_alloc

A later patch protects 'from' in rt6_info and this simplifies the
locking needed by it.

With the move, the fib6_info_hold for the uncached_rt is no longer
needed since the rcu_lock is still held.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 2d6fcfe11c827c2950a746d9b4bbab2d0fd380cc..f8b22183b7fd133594c4fbda738e30c07320d503 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1164,10 +1164,8 @@ static struct rt6_info *ip6_rt_cache_alloc(struct fib6_info *ort,
         *      Clone the route.
         */
 
-       rcu_read_lock();
        dev = ip6_rt_get_dev_rcu(ort);
        rt = ip6_dst_alloc(dev_net(dev), dev, 0);
-       rcu_read_unlock();
        if (!rt)
                return NULL;
 
@@ -1855,14 +1853,11 @@ redo_rt6_select:
                 * the daddr in the skb during the neighbor look-up is different
                 * from the fl6->daddr used to look-up route here.
                 */
-
                struct rt6_info *uncached_rt;
 
-               fib6_info_hold(f6i);
-               rcu_read_unlock();
-
                uncached_rt = ip6_rt_cache_alloc(f6i, &fl6->daddr, NULL);
-               fib6_info_release(f6i);
+
+               rcu_read_unlock();
 
                if (uncached_rt) {
                        /* Uncached_rt's refcnt is taken during ip6_rt_cache_alloc()
@@ -2280,7 +2275,9 @@ static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
        } else if (daddr) {
                struct rt6_info *nrt6;
 
+               rcu_read_lock();
                nrt6 = ip6_rt_cache_alloc(rt6->from, daddr, saddr);
+               rcu_read_unlock();
                if (nrt6) {
                        rt6_do_update_pmtu(nrt6, mtu);
                        if (rt6_insert_exception(nrt6, rt6->from))
@@ -3299,7 +3296,9 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
                                     NEIGH_UPDATE_F_ISROUTER)),
                     NDISC_REDIRECT, &ndopts);
 
+       rcu_read_lock();
        nrt = ip6_rt_cache_alloc(rt->from, &msg->dest, NULL);
+       rcu_read_unlock();
        if (!nrt)
                goto out;