Merge branch 'next' into for-linus

Prepare input updates for 5.4 merge window.

1 files changed, 31 insertions, 5 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 0ebc33d1c9e5..6e4afc48d7bb 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1153,6 +1153,8 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 	memset(skb->cb, 0, max(sizeof(struct inet_skb_parm),
 			       sizeof(struct inet6_skb_parm)));
 
+	tcp_add_tx_delay(skb, tp);
+
 	err = icsk->icsk_af_ops->queue_xmit(sk, skb, &inet->cork.fl);
 
 	if (unlikely(err > 0)) {
@@ -1286,6 +1288,7 @@ 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;
 
@@ -1296,8 +1299,16 @@ 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;
 	}
@@ -2239,6 +2250,18 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
 			      sock_net(sk)->ipv4.sysctl_tcp_limit_output_bytes);
 	limit <<= factor;
 
+	if (static_branch_unlikely(&tcp_tx_delay_enabled) &&
+	    tcp_sk(sk)->tcp_tx_delay) {
+		u64 extra_bytes = (u64)sk->sk_pacing_rate * tcp_sk(sk)->tcp_tx_delay;
+
+		/* TSQ is based on skb truesize sum (sk_wmem_alloc), so we
+		 * approximate our needs assuming an ~100% skb->truesize overhead.
+		 * USEC_PER_SEC is approximated by 2^20.
+		 * do_div(extra_bytes, USEC_PER_SEC/2) is replaced by a right shift.
+		 */
+		extra_bytes >>= (20 - 1);
+		limit += extra_bytes;
+	}
 	if (refcount_read(&sk->sk_wmem_alloc) > limit) {
 		/* Always send skb if rtx queue is empty.
 		 * No need to wait for TX completion to call us back,
@@ -3217,6 +3240,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 	int tcp_header_size;
 	struct tcphdr *th;
 	int mss;
+	u64 now;
 
 	skb = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
 	if (unlikely(!skb)) {
@@ -3248,13 +3272,14 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 	mss = tcp_mss_clamp(tp, dst_metric_advmss(dst));
 
 	memset(&opts, 0, sizeof(opts));
+	now = tcp_clock_ns();
 #ifdef CONFIG_SYN_COOKIES
 	if (unlikely(req->cookie_ts))
 		skb->skb_mstamp_ns = cookie_init_timestamp(req);
 	else
 #endif
 	{
-		skb->skb_mstamp_ns = tcp_clock_ns();
+		skb->skb_mstamp_ns = now;
 		if (!tcp_rsk(req)->snt_synack) /* Timestamp first SYNACK */
 			tcp_rsk(req)->snt_synack = tcp_skb_timestamp_us(skb);
 	}
@@ -3297,8 +3322,9 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 	rcu_read_unlock();
 #endif
 
-	/* Do not fool tcpdump (if any), clean our debris */
-	skb->tstamp = 0;
+	skb->skb_mstamp_ns = now;
+	tcp_add_tx_delay(skb, tp);
+
 	return skb;
 }
 EXPORT_SYMBOL(tcp_make_synack);