ipv4: avoid two atomic ops in ip_rt_redirect()
in_dev_get() -> __in_dev_get_rcu() in a rcu protected function.
[ Fix build with CONFIG_IP_ROUTE_VERBOSE disabled. -DaveM ]
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 7b8eacd..883b5c7 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1343,11 +1343,12 @@
spin_unlock_bh(rt_hash_lock_addr(hash));
}
+/* called in rcu_read_lock() section */
void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
__be32 saddr, struct net_device *dev)
{
int i, k;
- struct in_device *in_dev = in_dev_get(dev);
+ struct in_device *in_dev = __in_dev_get_rcu(dev);
struct rtable *rth, **rthp;
__be32 skeys[2] = { saddr, 0 };
int ikeys[2] = { dev->ifindex, 0 };
@@ -1383,7 +1384,6 @@
rthp=&rt_hash_table[hash].chain;
- rcu_read_lock();
while ((rth = rcu_dereference(*rthp)) != NULL) {
struct rtable *rt;
@@ -1405,12 +1405,10 @@
break;
dst_hold(&rth->u.dst);
- rcu_read_unlock();
rt = dst_alloc(&ipv4_dst_ops);
if (rt == NULL) {
ip_rt_put(rth);
- in_dev_put(in_dev);
return;
}
@@ -1463,12 +1461,10 @@
ip_rt_put(rt);
goto do_next;
}
- rcu_read_unlock();
do_next:
;
}
}
- in_dev_put(in_dev);
return;
reject_redirect:
@@ -1479,7 +1475,7 @@
&old_gw, dev->name, &new_gw,
&saddr, &daddr);
#endif
- in_dev_put(in_dev);
+ ;
}
static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)