ipv6: avoid two atomics in ipv6_rthdr_rcv()

Use __in6_dev_get() instead of in6_dev_get()/in6_dev_put()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 6 deletions

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 853a633a94d4..262f105d23b9 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -312,6 +312,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
   Routing header.
  ********************************/
 
+/* called with rcu_read_lock() */
 static int ipv6_rthdr_rcv(struct sk_buff *skb)
 {
         struct inet6_skb_parm *opt = IP6CB(skb);
@@ -324,12 +325,9 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb)
         struct net *net = dev_net(skb->dev);
         int accept_source_route = net->ipv6.devconf_all->accept_source_route;
 
-        idev = in6_dev_get(skb->dev);
-        if (idev) {
-                if (accept_source_route > idev->cnf.accept_source_route)
-                        accept_source_route = idev->cnf.accept_source_route;
-                in6_dev_put(idev);
-        }
+        idev = __in6_dev_get(skb->dev);
+        if (idev && accept_source_route > idev->cnf.accept_source_route)
+                accept_source_route = idev->cnf.accept_source_route;
 
         if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
             !pskb_may_pull(skb, (skb_transport_offset(skb) +