[PATCH] ipv6: use RCU in inet6_csk_xmit()
From: Eric Dumazet <hidden>
Date: 2011-07-28 13:43:51
Use RCU to avoid changing dst_entry refcount in fast path. Signed-off-by: Eric Dumazet <redacted> --- net/ipv6/inet6_connection_sock.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index 8a58e8c..2916200 100644
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c@@ -211,6 +211,7 @@ int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused) struct flowi6 fl6; struct dst_entry *dst; struct in6_addr *final_p, final; + int res; memset(&fl6, 0, sizeof(fl6)); fl6.flowi6_proto = sk->sk_protocol;
@@ -241,12 +242,14 @@ int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused) __inet6_csk_dst_store(sk, dst, NULL, NULL); } - skb_dst_set(skb, dst_clone(dst)); + rcu_read_lock(); + skb_dst_set_noref(skb, dst); /* Restore final destination back after routing done */ ipv6_addr_copy(&fl6.daddr, &np->daddr); - return ip6_xmit(sk, skb, &fl6, np->opt); + res = ip6_xmit(sk, skb, &fl6, np->opt); + rcu_read_unlock(); + return res; } - EXPORT_SYMBOL_GPL(inet6_csk_xmit);