1 files changed, 30 insertions, 6 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 4af1f5dae9d3..fec6d67bfd14 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1050,11 +1050,22 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 	tcb = TCP_SKB_CB(skb);
 	memset(&opts, 0, sizeof(opts));
 
-	if (unlikely(tcb->tcp_flags & TCPHDR_SYN))
+	if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
 		tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5);
-	else
+	} else {
 		tcp_options_size = tcp_established_options(sk, skb, &opts,
 							   &md5);
+		/* Force a PSH flag on all (GSO) packets to expedite GRO flush
+		 * at receiver : This slightly improve GRO performance.
+		 * Note that we do not force the PSH flag for non GSO packets,
+		 * because they might be sent under high congestion events,
+		 * and in this case it is better to delay the delivery of 1-MSS
+		 * packets and thus the corresponding ACK packet that would
+		 * release the following packet.
+		 */
+		if (tcp_skb_pcount(skb) > 1)
+			tcb->tcp_flags |= TCPHDR_PSH;
+	}
 	tcp_header_size = tcp_options_size + sizeof(struct tcphdr);
 
 	/* if no packet is in qdisc/device queue, then allow XPS to select
@@ -1288,6 +1299,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *buff;
 	int nsize, old_factor;
+	long limit;
 	int nlen;
 	u8 flags;
 
@@ -1298,8 +1310,16 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
 	if (nsize < 0)
 		nsize = 0;
 
-	if (unlikely((sk->sk_wmem_queued >> 1) > sk->sk_sndbuf &&
-		     tcp_queue != TCP_FRAG_IN_WRITE_QUEUE)) {
+	/* tcp_sendmsg() can overshoot sk_wmem_queued by one full size skb.
+	 * We need some allowance to not penalize applications setting small
+	 * SO_SNDBUF values.
+	 * Also allow first and last skb in retransmit queue to be split.
+	 */
+	limit = sk->sk_sndbuf + 2 * SKB_TRUESIZE(GSO_MAX_SIZE);
+	if (unlikely((sk->sk_wmem_queued >> 1) > limit &&
+		     tcp_queue != TCP_FRAG_IN_WRITE_QUEUE &&
+		     skb != tcp_rtx_queue_head(sk) &&
+		     skb != tcp_rtx_queue_tail(sk))) {
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPWQUEUETOOBIG);
 		return -ENOMEM;
 	}
@@ -1311,6 +1331,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
 	buff = sk_stream_alloc_skb(sk, nsize, gfp, true);
 	if (!buff)
 		return -ENOMEM; /* We'll just try again later. */
+	skb_copy_decrypted(buff, skb);
 
 	sk->sk_wmem_queued += buff->truesize;
 	sk_mem_charge(sk, buff->truesize);
@@ -1393,7 +1414,7 @@ static int __pskb_trim_head(struct sk_buff *skb, int len)
 		} else {
 			shinfo->frags[k] = shinfo->frags[i];
 			if (eat) {
-				shinfo->frags[k].page_offset += eat;
+				skb_frag_off_add(&shinfo->frags[k], eat);
 				skb_frag_size_sub(&shinfo->frags[k], eat);
 				eat = 0;
 			}
@@ -1865,6 +1886,7 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 	buff = sk_stream_alloc_skb(sk, 0, gfp, true);
 	if (unlikely(!buff))
 		return -ENOMEM;
+	skb_copy_decrypted(buff, skb);
 
 	sk->sk_wmem_queued += buff->truesize;
 	sk_mem_charge(sk, buff->truesize);
@@ -2042,7 +2064,7 @@ static bool tcp_can_coalesce_send_queue_head(struct sock *sk, int len)
 		if (len <= skb->len)
 			break;
 
-		if (unlikely(TCP_SKB_CB(skb)->eor))
+		if (unlikely(TCP_SKB_CB(skb)->eor) || tcp_has_tx_tstamp(skb))
 			return false;
 
 		len -= skb->len;
@@ -2134,6 +2156,7 @@ static int tcp_mtu_probe(struct sock *sk)
 	sk_mem_charge(sk, nskb->truesize);
 
 	skb = tcp_send_head(sk);
+	skb_copy_decrypted(nskb, skb);
 
 	TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
 	TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
@@ -2158,6 +2181,7 @@ static int tcp_mtu_probe(struct sock *sk)
 			 * we need to propagate it to the new skb.
 			 */
 			TCP_SKB_CB(nskb)->eor = TCP_SKB_CB(skb)->eor;
+			tcp_skb_collapse_tstamp(nskb, skb);
 			tcp_unlink_write_queue(skb, sk);
 			sk_wmem_free_skb(sk, skb);
 		} else {