1 files changed, 32 insertions, 4 deletions

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 29a2d690d8d5..5edc686faff1 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -879,12 +879,18 @@ static bool mptcp_skb_can_collapse_to(u64 write_seq,
 	       !mpext->frozen;
 }
 
+/* we can append data to the given data frag if:
+ * - there is space available in the backing page_frag
+ * - the data frag tail matches the current page_frag free offset
+ * - the data frag end sequence number matches the current write seq
+ */
 static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk,
 				       const struct page_frag *pfrag,
 				       const struct mptcp_data_frag *df)
 {
 	return df && pfrag->page == df->page &&
 		pfrag->size - pfrag->offset > 0 &&
+		pfrag->offset == (df->offset + df->data_len) &&
 		df->data_seq + df->data_len == msk->write_seq;
 }
 
@@ -941,6 +947,10 @@ static void __mptcp_update_wmem(struct sock *sk)
 {
 	struct mptcp_sock *msk = mptcp_sk(sk);
 
+#ifdef CONFIG_LOCKDEP
+	WARN_ON_ONCE(!lockdep_is_held(&sk->sk_lock.slock));
+#endif
+
 	if (!msk->wmem_reserved)
 		return;
 
@@ -1079,10 +1089,20 @@ out:
 
 static void __mptcp_clean_una_wakeup(struct sock *sk)
 {
+#ifdef CONFIG_LOCKDEP
+	WARN_ON_ONCE(!lockdep_is_held(&sk->sk_lock.slock));
+#endif
 	__mptcp_clean_una(sk);
 	mptcp_write_space(sk);
 }
 
+static void mptcp_clean_una_wakeup(struct sock *sk)
+{
+	mptcp_data_lock(sk);
+	__mptcp_clean_una_wakeup(sk);
+	mptcp_data_unlock(sk);
+}
+
 static void mptcp_enter_memory_pressure(struct sock *sk)
 {
 	struct mptcp_subflow_context *subflow;
@@ -2293,7 +2313,7 @@ static void __mptcp_retrans(struct sock *sk)
 	struct sock *ssk;
 	int ret;
 
-	__mptcp_clean_una_wakeup(sk);
+	mptcp_clean_una_wakeup(sk);
 	dfrag = mptcp_rtx_head(sk);
 	if (!dfrag) {
 		if (mptcp_data_fin_enabled(msk)) {
@@ -2418,13 +2438,12 @@ static int __mptcp_init_sock(struct sock *sk)
 	timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0);
 	timer_setup(&sk->sk_timer, mptcp_timeout_timer, 0);
 
-	tcp_assign_congestion_control(sk);
-
 	return 0;
 }
 
 static int mptcp_init_sock(struct sock *sk)
 {
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct net *net = sock_net(sk);
 	int ret;
 
@@ -2442,6 +2461,16 @@ static int mptcp_init_sock(struct sock *sk)
 	if (ret)
 		return ret;
 
+	/* fetch the ca name; do it outside __mptcp_init_sock(), so that clone will
+	 * propagate the correct value
+	 */
+	tcp_assign_congestion_control(sk);
+	strcpy(mptcp_sk(sk)->ca_name, icsk->icsk_ca_ops->name);
+
+	/* no need to keep a reference to the ops, the name will suffice */
+	tcp_cleanup_congestion_control(sk);
+	icsk->icsk_ca_ops = NULL;
+
 	sk_sockets_allocated_inc(sk);
 	sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];
 	sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1];
@@ -2616,7 +2645,6 @@ static void __mptcp_destroy_sock(struct sock *sk)
 	sk_stream_kill_queues(sk);
 	xfrm_sk_free_policy(sk);
 
-	tcp_cleanup_congestion_control(sk);
 	sk_refcnt_debug_release(sk);
 	mptcp_dispose_initial_subflow(msk);
 	sock_put(sk);