ipv6: some RCU conversions

ICMP and ND are not fast path, but still we can avoid changing idev
refcount, using RCU.

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

1 files changed, 10 insertions, 15 deletions

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 11900417b1cc..2b59154c65d3 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -490,7 +490,8 @@ void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
                 goto out_dst_release;
         }
 
-        idev = in6_dev_get(skb->dev);
+        rcu_read_lock();
+        idev = __in6_dev_get(skb->dev);
 
         err = ip6_append_data(sk, icmpv6_getfrag, &msg,
                               len + sizeof(struct icmp6hdr),
@@ -500,19 +501,16 @@ void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
         if (err) {
                 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
                 ip6_flush_pending_frames(sk);
-                goto out_put;
+        } else {
+                err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
+                                                 len + sizeof(struct icmp6hdr));
         }
-        err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, len + sizeof(struct icmp6hdr));
-
-out_put:
-        if (likely(idev != NULL))
-                in6_dev_put(idev);
+        rcu_read_unlock();
 out_dst_release:
         dst_release(dst);
 out:
         icmpv6_xmit_unlock(sk);
 }
-
 EXPORT_SYMBOL(icmpv6_send);
 
 static void icmpv6_echo_reply(struct sk_buff *skb)
@@ -569,7 +567,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
         if (hlimit < 0)
                 hlimit = ip6_dst_hoplimit(dst);
 
-        idev = in6_dev_get(skb->dev);
+        idev = __in6_dev_get(skb->dev);
 
         msg.skb = skb;
         msg.offset = 0;
@@ -583,13 +581,10 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
         if (err) {
                 ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
                 ip6_flush_pending_frames(sk);
-                goto out_put;
+        } else {
+                err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
+                                                 skb->len + sizeof(struct icmp6hdr));
         }
-        err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, skb->len + sizeof(struct icmp6hdr));
-
-out_put:
-        if (likely(idev != NULL))
-                in6_dev_put(idev);
         dst_release(dst);
 out:
         icmpv6_xmit_unlock(sk);