1 files changed, 30 insertions, 4 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e9f985e..6818042 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1730,7 +1730,7 @@ u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now,
 	 */
 	segs = max_t(u32, bytes / mss_now, min_tso_segs);
 
-	return min_t(u32, segs, sk->sk_gso_max_segs);
+	return segs;
 }
 EXPORT_SYMBOL(tcp_tso_autosize);
 
@@ -1742,9 +1742,10 @@ static u32 tcp_tso_segs(struct sock *sk, unsigned int mss_now)
 	const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops;
 	u32 tso_segs = ca_ops->tso_segs_goal ? ca_ops->tso_segs_goal(sk) : 0;
 
-	return tso_segs ? :
-		tcp_tso_autosize(sk, mss_now,
-				 sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs);
+	if (!tso_segs)
+		tso_segs = tcp_tso_autosize(sk, mss_now,
+				sock_net(sk)->ipv4.sysctl_tcp_min_tso_segs);
+	return min_t(u32, tso_segs, sk->sk_gso_max_segs);
 }
 
 /* Returns the portion of skb which can be sent right away */
@@ -2027,6 +2028,24 @@ static inline void tcp_mtu_check_reprobe(struct sock *sk)
 	}
 }
 
+static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len)
+{
+	struct sk_buff *skb, *next;
+
+	skb = tcp_send_head(sk);
+	tcp_for_write_queue_from_safe(skb, next, sk) {
+		if (len <= skb->len)
+			break;
+
+		if (unlikely(TCP_SKB_CB(skb)->eor))
+			return false;
+
+		len -= skb->len;
+	}
+
+	return true;
+}
+
 /* Create a new MTU probe if we are ready.
  * MTU probe is regularly attempting to increase the path MTU by
  * deliberately sending larger packets.  This discovers routing
@@ -2099,6 +2118,9 @@ static int tcp_mtu_probe(struct sock *sk)
 			return 0;
 	}
 
+	if (!tcp_can_coalesce_send_queue_head(sk, probe_size))
+		return -1;
+
 	/* We're allowed to probe.  Build it now. */
 	nskb = sk_stream_alloc_skb(sk, probe_size, GFP_ATOMIC, false);
 	if (!nskb)
@@ -2134,6 +2156,10 @@ static int tcp_mtu_probe(struct sock *sk)
 			/* We've eaten all the data from this skb.
 			 * Throw it away. */
 			TCP_SKB_CB(nskb)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags;
+			/* If this is the last SKB we copy and eor is set
+			 * we need to propagate it to the new skb.
+			 */
+			TCP_SKB_CB(nskb)->eor = TCP_SKB_CB(skb)->eor;
 			tcp_unlink_write_queue(skb, sk);
 			sk_wmem_free_skb(sk, skb);
 		} else {