1 files changed, 27 insertions, 10 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 141e85e6422b..246ab7b5e857 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -500,8 +500,11 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb,
 
 	room = min_t(int, tp->window_clamp, tcp_space(sk)) - tp->rcv_ssthresh;
 
+	if (room <= 0)
+		return;
+
 	/* Check #1 */
-	if (room > 0 && !tcp_under_memory_pressure(sk)) {
+	if (!tcp_under_memory_pressure(sk)) {
 		unsigned int truesize = truesize_adjust(adjust, skb);
 		int incr;
 
@@ -518,6 +521,11 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb,
 			tp->rcv_ssthresh += min(room, incr);
 			inet_csk(sk)->icsk_ack.quick |= 1;
 		}
+	} else {
+		/* Under pressure:
+		 * Adjust rcv_ssthresh according to reserved mem
+		 */
+		tcp_adjust_rcv_ssthresh(sk);
 	}
 }
 
@@ -3221,7 +3229,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, const struct sk_buff *ack_skb,
 	long seq_rtt_us = -1L;
 	long ca_rtt_us = -1L;
 	u32 pkts_acked = 0;
-	u32 last_in_flight = 0;
 	bool rtt_update;
 	int flag = 0;
 
@@ -3257,7 +3264,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, const struct sk_buff *ack_skb,
 			if (!first_ackt)
 				first_ackt = last_ackt;
 
-			last_in_flight = TCP_SKB_CB(skb)->tx.in_flight;
 			if (before(start_seq, reord))
 				reord = start_seq;
 			if (!after(scb->end_seq, tp->high_seq))
@@ -3323,8 +3329,8 @@ static int tcp_clean_rtx_queue(struct sock *sk, const struct sk_buff *ack_skb,
 		seq_rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, first_ackt);
 		ca_rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, last_ackt);
 
-		if (pkts_acked == 1 && last_in_flight < tp->mss_cache &&
-		    last_in_flight && !prior_sacked && fully_acked &&
+		if (pkts_acked == 1 && fully_acked && !prior_sacked &&
+		    (tp->snd_una - prior_snd_una) < tp->mss_cache &&
 		    sack->rate->prior_delivered + 1 == tp->delivered &&
 		    !(flag & (FLAG_CA_ALERT | FLAG_SYN_ACKED))) {
 			/* Conservatively mark a delayed ACK. It's typically
@@ -3381,9 +3387,10 @@ static int tcp_clean_rtx_queue(struct sock *sk, const struct sk_buff *ack_skb,
 
 	if (icsk->icsk_ca_ops->pkts_acked) {
 		struct ack_sample sample = { .pkts_acked = pkts_acked,
-					     .rtt_us = sack->rate->rtt_us,
-					     .in_flight = last_in_flight };
+					     .rtt_us = sack->rate->rtt_us };
 
+		sample.in_flight = tp->mss_cache *
+			(tp->delivered - sack->rate->prior_delivered);
 		icsk->icsk_ca_ops->pkts_acked(sk, &sample);
 	}
 
@@ -5346,7 +5353,7 @@ static int tcp_prune_queue(struct sock *sk)
 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
 		tcp_clamp_window(sk);
 	else if (tcp_under_memory_pressure(sk))
-		tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss);
+		tcp_adjust_rcv_ssthresh(sk);
 
 	if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf)
 		return 0;
@@ -5381,7 +5388,7 @@ static int tcp_prune_queue(struct sock *sk)
 	return -1;
 }
 
-static bool tcp_should_expand_sndbuf(const struct sock *sk)
+static bool tcp_should_expand_sndbuf(struct sock *sk)
 {
 	const struct tcp_sock *tp = tcp_sk(sk);
 
@@ -5392,8 +5399,18 @@ static bool tcp_should_expand_sndbuf(const struct sock *sk)
 		return false;
 
 	/* If we are under global TCP memory pressure, do not expand.  */
-	if (tcp_under_memory_pressure(sk))
+	if (tcp_under_memory_pressure(sk)) {
+		int unused_mem = sk_unused_reserved_mem(sk);
+
+		/* Adjust sndbuf according to reserved mem. But make sure
+		 * it never goes below SOCK_MIN_SNDBUF.
+		 * See sk_stream_moderate_sndbuf() for more details.
+		 */
+		if (unused_mem > SOCK_MIN_SNDBUF)
+			WRITE_ONCE(sk->sk_sndbuf, unused_mem);
+
 		return false;
+	}
 
 	/* If we are under soft global TCP memory pressure, do not expand.  */
 	if (sk_memory_allocated(sk) >= sk_prot_mem_limits(sk, 0))