arp: RCU changes
Avoid two atomic ops in arp_fwd_proxy()
Avoid two atomic ops in arp_process()
Valid optims since arp_rcv() is run under rcu_read_lock()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index f094b75..917d2d6 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -545,10 +545,10 @@
/* place to check for proxy_arp for routes */
- if ((out_dev = in_dev_get(rt->u.dst.dev)) != NULL) {
+ out_dev = __in_dev_get_rcu(rt->u.dst.dev);
+ if (out_dev)
omi = IN_DEV_MEDIUM_ID(out_dev);
- in_dev_put(out_dev);
- }
+
return (omi != imi && omi != -1);
}
@@ -741,7 +741,7 @@
static int arp_process(struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
- struct in_device *in_dev = in_dev_get(dev);
+ struct in_device *in_dev = __in_dev_get_rcu(dev);
struct arphdr *arp;
unsigned char *arp_ptr;
struct rtable *rt;
@@ -890,7 +890,6 @@
arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha);
} else {
pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb);
- in_dev_put(in_dev);
return 0;
}
goto out;
@@ -936,8 +935,6 @@
}
out:
- if (in_dev)
- in_dev_put(in_dev);
consume_skb(skb);
return 0;
}