1 files changed, 19 insertions, 11 deletions

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index e212c1374bd0..f505b780f713 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1623,7 +1623,7 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags)
 	struct mptcp_sendmsg_info info = {
 				.flags = flags,
 	};
-	bool do_check_data_fin = false;
+	bool copied = false;
 	int push_count = 1;
 
 	while (mptcp_send_head(sk) && (push_count > 0)) {
@@ -1665,7 +1665,7 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags)
 						push_count--;
 					continue;
 				}
-				do_check_data_fin = true;
+				copied = true;
 			}
 		}
 	}
@@ -1674,11 +1674,14 @@ void __mptcp_push_pending(struct sock *sk, unsigned int flags)
 	if (ssk)
 		mptcp_push_release(ssk, &info);
 
-	/* ensure the rtx timer is running */
-	if (!mptcp_rtx_timer_pending(sk))
-		mptcp_reset_rtx_timer(sk);
-	if (do_check_data_fin)
+	/* Avoid scheduling the rtx timer if no data has been pushed; the timer
+	 * will be updated on positive acks by __mptcp_cleanup_una().
+	 */
+	if (copied) {
+		if (!mptcp_rtx_timer_pending(sk))
+			mptcp_reset_rtx_timer(sk);
 		mptcp_check_send_data_fin(sk);
+	}
 }
 
 static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk, bool first)
@@ -2464,10 +2467,10 @@ bool __mptcp_retransmit_pending_data(struct sock *sk)
  */
 static void __mptcp_subflow_disconnect(struct sock *ssk,
 				       struct mptcp_subflow_context *subflow,
-				       unsigned int flags)
+				       bool fastclosing)
 {
 	if (((1 << ssk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) ||
-	    subflow->send_fastclose) {
+	    fastclosing) {
 		/* The MPTCP code never wait on the subflow sockets, TCP-level
 		 * disconnect should never fail
 		 */
@@ -2535,7 +2538,7 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
 
 	need_push = (flags & MPTCP_CF_PUSH) && __mptcp_retransmit_pending_data(sk);
 	if (!dispose_it) {
-		__mptcp_subflow_disconnect(ssk, subflow, flags);
+		__mptcp_subflow_disconnect(ssk, subflow, msk->fastclosing);
 		release_sock(ssk);
 
 		goto out;
@@ -2766,10 +2769,13 @@ static void __mptcp_retrans(struct sock *sk)
 
 			/*
 			 * make the whole retrans decision, xmit, disallow
-			 * fallback atomic
+			 * fallback atomic, note that we can't retrans even
+			 * when an infinite fallback is in progress, i.e. new
+			 * subflows are disallowed.
 			 */
 			spin_lock_bh(&msk->fallback_lock);
-			if (__mptcp_check_fallback(msk)) {
+			if (__mptcp_check_fallback(msk) ||
+			    !msk->allow_subflows) {
 				spin_unlock_bh(&msk->fallback_lock);
 				release_sock(ssk);
 				goto clear_scheduled;
@@ -2878,6 +2884,7 @@ static void mptcp_do_fastclose(struct sock *sk)
 
 	mptcp_set_state(sk, TCP_CLOSE);
 	mptcp_backlog_purge(sk);
+	msk->fastclosing = 1;
 
 	/* Explicitly send the fastclose reset as need */
 	if (__mptcp_check_fallback(msk))
@@ -3412,6 +3419,7 @@ static int mptcp_disconnect(struct sock *sk, int flags)
 	msk->bytes_sent = 0;
 	msk->bytes_retrans = 0;
 	msk->rcvspace_init = 0;
+	msk->fastclosing = 0;
 
 	/* for fallback's sake */
 	WRITE_ONCE(msk->ack_seq, 0);