From 4b4194c40f4ac8d03a700845f8978cba53246b5a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 22 Jun 2010 07:43:15 +0000 Subject: [PATCH] arp: RCU change in arp_solicit() Avoid two atomic ops in arp_solicit() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/arp.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index cf78f41830ca..09ead1baa99e 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -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); -- 2.39.5