1 files changed, 34 insertions, 15 deletions

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index f2930699c6d3..b6dc6e260334 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1673,6 +1673,37 @@ static void mptcp_set_nospace(struct sock *sk)
 	set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags);
 }
 
+static int mptcp_sendmsg_fastopen(struct sock *sk, struct sock *ssk, struct msghdr *msg,
+				  size_t len, int *copied_syn)
+{
+	unsigned int saved_flags = msg->msg_flags;
+	struct mptcp_sock *msk = mptcp_sk(sk);
+	int ret;
+
+	lock_sock(ssk);
+	msg->msg_flags |= MSG_DONTWAIT;
+	msk->connect_flags = O_NONBLOCK;
+	msk->is_sendmsg = 1;
+	ret = tcp_sendmsg_fastopen(ssk, msg, copied_syn, len, NULL);
+	msk->is_sendmsg = 0;
+	msg->msg_flags = saved_flags;
+	release_sock(ssk);
+
+	/* do the blocking bits of inet_stream_connect outside the ssk socket lock */
+	if (ret == -EINPROGRESS && !(msg->msg_flags & MSG_DONTWAIT)) {
+		ret = __inet_stream_connect(sk->sk_socket, msg->msg_name,
+					    msg->msg_namelen, msg->msg_flags, 1);
+
+		/* Keep the same behaviour of plain TCP: zero the copied bytes in
+		 * case of any error, except timeout or signal
+		 */
+		if (ret && ret != -EINPROGRESS && ret != -ERESTARTSYS && ret != -EINTR)
+			*copied_syn = 0;
+	}
+
+	return ret;
+}
+
 static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 {
 	struct mptcp_sock *msk = mptcp_sk(sk);
@@ -1693,26 +1724,14 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
 	ssock = __mptcp_nmpc_socket(msk);
 	if (unlikely(ssock && inet_sk(ssock->sk)->defer_connect)) {
-		struct sock *ssk = ssock->sk;
 		int copied_syn = 0;
 
-		lock_sock(ssk);
-
-		msk->connect_flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
-		msk->is_sendmsg = 1;
-		ret = tcp_sendmsg_fastopen(ssk, msg, &copied_syn, len, NULL);
-		msk->is_sendmsg = 0;
+		ret = mptcp_sendmsg_fastopen(sk, ssock->sk, msg, len, &copied_syn);
 		copied += copied_syn;
-		if (ret == -EINPROGRESS && copied_syn > 0) {
-			/* reflect the new state on the MPTCP socket */
-			inet_sk_state_store(sk, inet_sk_state_load(ssk));
-			release_sock(ssk);
+		if (ret == -EINPROGRESS && copied_syn > 0)
 			goto out;
-		} else if (ret) {
-			release_sock(ssk);
+		else if (ret)
 			goto do_error;
-		}
-		release_sock(ssk);
 	}
 
 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);