mptcp: move msk state update to subflow_syn_recv_sock()

After commit 58b09919 ("mptcp: create msk early"), the
msk socket is already available at subflow_syn_recv_sock()
time. Let's move there the state update, to mirror more
closely the first subflow state.

The above will also help multiple subflow supports.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/protocol.c

@@ -861,6 +861,9 @@ struct sock *mptcp_sk_clone(const struct sock *sk, struct request_sock *req)
 		ack_seq++;
 		msk->ack_seq = ack_seq;
 	}
+
+	/* will be fully established after successful MPC subflow creation */
+	inet_sk_state_store(nsk, TCP_SYN_RECV);
 	bh_unlock_sock(nsk);
 
 	/* keep a single reference */
@@ -916,10 +919,6 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
 		mptcp_copy_inaddrs(newsk, ssk);
 		list_add(&subflow->node, &msk->conn_list);
 
-		/* will be fully established at mptcp_stream_accept()
-		 * completion.
-		 */
-		inet_sk_state_store(new_mptcp_sock, TCP_SYN_RECV);
 		bh_unlock_sock(new_mptcp_sock);
 		local_bh_enable();
 	}
@@ -1256,8 +1255,6 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
 			if (!ssk->sk_socket)
 				mptcp_sock_graft(ssk, newsock);
 		}
-
-		inet_sk_state_store(newsock->sk, TCP_ESTABLISHED);
 	}
 
 	sock_put(ssock->sk);

net/mptcp/subflow.c

@@ -234,6 +234,8 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk,
 			/* new mpc subflow takes ownership of the newly
 			 * created mptcp socket
 			 */
+			inet_sk_state_store((struct sock *)new_msk,
+					    TCP_ESTABLISHED);
 			ctx->conn = new_msk;
 			new_msk = NULL;
 		}