1 files changed, 39 insertions, 44 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 730bc44dbad9..4522579aaca2 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -165,13 +165,16 @@ static void tcp_event_data_sent(struct tcp_sock *tp,
 	if (tcp_packets_in_flight(tp) == 0)
 		tcp_ca_event(sk, CA_EVENT_TX_START);
 
-	tp->lsndtime = now;
-
-	/* If it is a reply for ato after last received
-	 * packet, enter pingpong mode.
+	/* If this is the first data packet sent in response to the
+	 * previous received data,
+	 * and it is a reply for ato after last received packet,
+	 * increase pingpong count.
 	 */
-	if ((u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato)
-		icsk->icsk_ack.pingpong = 1;
+	if (before(tp->lsndtime, icsk->icsk_ack.lrcvtime) &&
+	    (u32)(now - icsk->icsk_ack.lrcvtime) < icsk->icsk_ack.ato)
+		inet_csk_inc_pingpong_cnt(sk);
+
+	tp->lsndtime = now;
 }
 
 /* Account for an ACK we sent. */
@@ -594,7 +597,7 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 
 	*md5 = NULL;
 #ifdef CONFIG_TCP_MD5SIG
-	if (static_key_false(&tcp_md5_needed) &&
+	if (static_branch_unlikely(&tcp_md5_needed) &&
 	    rcu_access_pointer(tp->md5sig_info)) {
 		*md5 = tp->af_specific->md5_lookup(sk, sk);
 		if (*md5) {
@@ -731,7 +734,7 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
 
 	*md5 = NULL;
 #ifdef CONFIG_TCP_MD5SIG
-	if (static_key_false(&tcp_md5_needed) &&
+	if (static_branch_unlikely(&tcp_md5_needed) &&
 	    rcu_access_pointer(tp->md5sig_info)) {
 		*md5 = tp->af_specific->md5_lookup(sk, sk);
 		if (*md5) {
@@ -980,7 +983,6 @@ static void tcp_update_skb_after_send(struct sock *sk, struct sk_buff *skb,
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 
-	skb->skb_mstamp_ns = tp->tcp_wstamp_ns;
 	if (sk->sk_pacing_status != SK_PACING_NONE) {
 		unsigned long rate = sk->sk_pacing_rate;
 
@@ -1028,7 +1030,9 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 
 	BUG_ON(!skb || !tcp_skb_pcount(skb));
 	tp = tcp_sk(sk);
-
+	prior_wstamp = tp->tcp_wstamp_ns;
+	tp->tcp_wstamp_ns = max(tp->tcp_wstamp_ns, tp->tcp_clock_cache);
+	skb->skb_mstamp_ns = tp->tcp_wstamp_ns;
 	if (clone_it) {
 		TCP_SKB_CB(skb)->tx.in_flight = TCP_SKB_CB(skb)->end_seq
 			- tp->snd_una;
@@ -1045,11 +1049,6 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 			return -ENOBUFS;
 	}
 
-	prior_wstamp = tp->tcp_wstamp_ns;
-	tp->tcp_wstamp_ns = max(tp->tcp_wstamp_ns, tp->tcp_clock_cache);
-
-	skb->skb_mstamp_ns = tp->tcp_wstamp_ns;
-
 	inet = inet_sk(sk);
 	tcb = TCP_SKB_CB(skb);
 	memset(&opts, 0, sizeof(opts));
@@ -1847,17 +1846,17 @@ static bool tcp_snd_wnd_test(const struct tcp_sock *tp,
  * know that all the data is in scatter-gather pages, and that the
  * packet has never been sent out before (and thus is not cloned).
  */
-static int tso_fragment(struct sock *sk, enum tcp_queue tcp_queue,
-			struct sk_buff *skb, unsigned int len,
+static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
 			unsigned int mss_now, gfp_t gfp)
 {
-	struct sk_buff *buff;
 	int nlen = skb->len - len;
+	struct sk_buff *buff;
 	u8 flags;
 
 	/* All of a TSO frame must be composed of paged data.  */
 	if (skb->len != skb->data_len)
-		return tcp_fragment(sk, tcp_queue, skb, len, mss_now, gfp);
+		return tcp_fragment(sk, TCP_FRAG_IN_WRITE_QUEUE,
+				    skb, len, mss_now, gfp);
 
 	buff = sk_stream_alloc_skb(sk, 0, gfp, true);
 	if (unlikely(!buff))
@@ -1893,7 +1892,7 @@ static int tso_fragment(struct sock *sk, enum tcp_queue tcp_queue,
 
 	/* Link BUFF into the send queue. */
 	__skb_header_release(buff);
-	tcp_insert_write_queue_after(skb, buff, sk, tcp_queue);
+	tcp_insert_write_queue_after(skb, buff, sk, TCP_FRAG_IN_WRITE_QUEUE);
 
 	return 0;
 }
@@ -2347,6 +2346,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 			/* "skb_mstamp_ns" is used as a start point for the retransmit timer */
 			skb->skb_mstamp_ns = tp->tcp_wstamp_ns = tp->tcp_clock_cache;
 			list_move_tail(&skb->tcp_tsorted_anchor, &tp->tsorted_sent_queue);
+			tcp_init_tso_segs(skb, mss_now);
 			goto repair; /* Skip network transmission */
 		}
 
@@ -2391,8 +2391,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 						    nonagle);
 
 		if (skb->len > limit &&
-		    unlikely(tso_fragment(sk, TCP_FRAG_IN_WRITE_QUEUE,
-					  skb, limit, mss_now, gfp)))
+		    unlikely(tso_fragment(sk, skb, limit, mss_now, gfp)))
 			break;
 
 		if (tcp_small_queue_check(sk, skb, 0))
@@ -2937,12 +2936,16 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
 		err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
 	}
 
+	/* To avoid taking spuriously low RTT samples based on a timestamp
+	 * for a transmit that never happened, always mark EVER_RETRANS
+	 */
+	TCP_SKB_CB(skb)->sacked |= TCPCB_EVER_RETRANS;
+
 	if (BPF_SOCK_OPS_TEST_FLAG(tp, BPF_SOCK_OPS_RETRANS_CB_FLAG))
 		tcp_call_bpf_3arg(sk, BPF_SOCK_OPS_RETRANS_CB,
 				  TCP_SKB_CB(skb)->seq, segs, err);
 
 	if (likely(!err)) {
-		TCP_SKB_CB(skb)->sacked |= TCPCB_EVER_RETRANS;
 		trace_tcp_retransmit_skb(sk, skb);
 	} else if (err != -EBUSY) {
 		NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL, segs);
@@ -2963,13 +2966,12 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
 #endif
 		TCP_SKB_CB(skb)->sacked |= TCPCB_RETRANS;
 		tp->retrans_out += tcp_skb_pcount(skb);
-
-		/* Save stamp of the first retransmit. */
-		if (!tp->retrans_stamp)
-			tp->retrans_stamp = tcp_skb_timestamp(skb);
-
 	}
 
+	/* Save stamp of the first (attempted) retransmit. */
+	if (!tp->retrans_stamp)
+		tp->retrans_stamp = tcp_skb_timestamp(skb);
+
 	if (tp->undo_retrans < 0)
 		tp->undo_retrans = 0;
 	tp->undo_retrans += tcp_skb_pcount(skb);
@@ -3456,6 +3458,7 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
 			skb_trim(syn_data, copied);
 			space = copied;
 		}
+		skb_zcopy_set(syn_data, fo->uarg, NULL);
 	}
 	/* No more data pending in inet_wait_for_connect() */
 	if (space == fo->size)
@@ -3569,7 +3572,7 @@ void tcp_send_delayed_ack(struct sock *sk)
 		const struct tcp_sock *tp = tcp_sk(sk);
 		int max_ato = HZ / 2;
 
-		if (icsk->icsk_ack.pingpong ||
+		if (inet_csk_in_pingpong_mode(sk) ||
 		    (icsk->icsk_ack.pending & ICSK_ACK_PUSHED))
 			max_ato = TCP_DELACK_MAX;
 
@@ -3750,7 +3753,7 @@ void tcp_send_probe0(struct sock *sk)
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct net *net = sock_net(sk);
-	unsigned long probe_max;
+	unsigned long timeout;
 	int err;
 
 	err = tcp_write_wakeup(sk, LINUX_MIB_TCPWINPROBE);
@@ -3762,26 +3765,18 @@ void tcp_send_probe0(struct sock *sk)
 		return;
 	}
 
+	icsk->icsk_probes_out++;
 	if (err <= 0) {
 		if (icsk->icsk_backoff < net->ipv4.sysctl_tcp_retries2)
 			icsk->icsk_backoff++;
-		icsk->icsk_probes_out++;
-		probe_max = TCP_RTO_MAX;
+		timeout = tcp_probe0_when(sk, TCP_RTO_MAX);
 	} else {
 		/* If packet was not sent due to local congestion,
-		 * do not backoff and do not remember icsk_probes_out.
-		 * Let local senders to fight for local resources.
-		 *
-		 * Use accumulated backoff yet.
+		 * Let senders fight for local resources conservatively.
 		 */
-		if (!icsk->icsk_probes_out)
-			icsk->icsk_probes_out = 1;
-		probe_max = TCP_RESOURCE_PROBE_INTERVAL;
-	}
-	tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
-			     tcp_probe0_when(sk, probe_max),
-			     TCP_RTO_MAX,
-			     NULL);
+		timeout = TCP_RESOURCE_PROBE_INTERVAL;
+	}
+	tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, timeout, TCP_RTO_MAX, NULL);
 }
 
 int tcp_rtx_synack(const struct sock *sk, struct request_sock *req)