arp: RCU change in arp_solicit()

Avoid two atomic ops in arp_solicit()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-06-22 07:43:15 +00:00 committed by David S. Miller
parent 59b80802a8
commit 4b4194c40f

View File

@ -333,11 +333,14 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
struct net_device *dev = neigh->dev;
__be32 target = *(__be32*)neigh->primary_key;
int probes = atomic_read(&neigh->probes);
struct in_device *in_dev = in_dev_get(dev);
struct in_device *in_dev;
if (!in_dev)
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
if (!in_dev) {
rcu_read_unlock();
return;
}
switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
default:
case 0: /* By default announce any local IP */
@ -358,9 +361,8 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
case 2: /* Avoid secondary IPs, get a primary/preferred one */
break;
}
rcu_read_unlock();
if (in_dev)
in_dev_put(in_dev);
if (!saddr)
saddr = inet_select_addr(dev, target, RT_SCOPE_LINK);