net: make skb_set_owner_w() more robust

skb_set_owner_w() is called from various places that assume
skb->sk always point to a full blown socket (as it changes
sk->sk_wmem_alloc)

We'd like to attach skb to request sockets, and in the future
to timewait sockets as well. For these kind of pseudo sockets,
we need to take a traditional refcount and use sock_edemux()
as the destructor.

It is now time to un-inline skb_set_owner_w(), being too big.

Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Bisected-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f4f9793..cb7ca56 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2963,9 +2963,7 @@
 	skb_reserve(skb, MAX_TCP_HEADER);
 
 	if (attach_req) {
-		skb->destructor = sock_edemux;
-		sock_hold(req_to_sk(req));
-		skb->sk = req_to_sk(req);
+		skb_set_owner_w(skb, req_to_sk(req));
 	} else {
 		/* sk is a const pointer, because we want to express multiple
 		 * cpu might call us concurrently.