Merge remote-tracking branch 'net-next/master' into mac80211-next

Resolve the merge conflict between Felix's/my and Toke's patches
coming into the tree through net and mac80211-next respectively.
Most of Felix's changes go away due to Toke's new infrastructure
work, my patch changes to "goto begin" (the label wasn't there
before) instead of returning NULL so flow control towards drivers
is preserved better.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 82 insertions, 36 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8b45794eb6b2..896e9dfbdb5c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -734,9 +734,16 @@ static void tcp_tsq_handler(struct sock *sk)
 {
 	if ((1 << sk->sk_state) &
 	    (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_CLOSING |
-	     TCPF_CLOSE_WAIT  | TCPF_LAST_ACK))
-		tcp_write_xmit(sk, tcp_current_mss(sk), tcp_sk(sk)->nonagle,
+	     TCPF_CLOSE_WAIT  | TCPF_LAST_ACK)) {
+		struct tcp_sock *tp = tcp_sk(sk);
+
+		if (tp->lost_out > tp->retrans_out &&
+		    tp->snd_cwnd > tcp_packets_in_flight(tp))
+			tcp_xmit_retransmit_queue(sk);
+
+		tcp_write_xmit(sk, tcp_current_mss(sk), tp->nonagle,
 			       0, GFP_ATOMIC);
+	}
 }
 /*
  * One tasklet per cpu tries to send more skbs.
@@ -918,6 +925,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 		skb_mstamp_get(&skb->skb_mstamp);
 		TCP_SKB_CB(skb)->tx.in_flight = TCP_SKB_CB(skb)->end_seq
 			- tp->snd_una;
+		tcp_rate_skb_sent(sk, skb);
 
 		if (unlikely(skb_cloned(skb)))
 			skb = pskb_copy(skb, gfp_mask);
@@ -1213,6 +1221,9 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
 	tcp_set_skb_tso_segs(skb, mss_now);
 	tcp_set_skb_tso_segs(buff, mss_now);
 
+	/* Update delivered info for the new segment */
+	TCP_SKB_CB(buff)->tx = TCP_SKB_CB(skb)->tx;
+
 	/* If this packet has been sent out already, we must
 	 * adjust the various packet counters.
 	 */
@@ -1358,6 +1369,7 @@ int tcp_mss_to_mtu(struct sock *sk, int mss)
 	}
 	return mtu;
 }
+EXPORT_SYMBOL(tcp_mss_to_mtu);
 
 /* MTU probing init per socket */
 void tcp_mtup_init(struct sock *sk)
@@ -1545,7 +1557,8 @@ static bool tcp_nagle_check(bool partial, const struct tcp_sock *tp,
 /* Return how many segs we'd like on a TSO packet,
  * to send one TSO packet per ms
  */
-static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now)
+u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now,
+		     int min_tso_segs)
 {
 	u32 bytes, segs;
 
@@ -1557,10 +1570,23 @@ static u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now)
 	 * This preserves ACK clocking and is consistent
 	 * with tcp_tso_should_defer() heuristic.
 	 */
-	segs = max_t(u32, bytes / mss_now, sysctl_tcp_min_tso_segs);
+	segs = max_t(u32, bytes / mss_now, min_tso_segs);
 
 	return min_t(u32, segs, sk->sk_gso_max_segs);
 }
+EXPORT_SYMBOL(tcp_tso_autosize);
+
+/* Return the number of segments we want in the skb we are transmitting.
+ * See if congestion control module wants to decide; otherwise, autosize.
+ */
+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, sysctl_tcp_min_tso_segs);
+}
 
 /* Returns the portion of skb which can be sent right away */
 static unsigned int tcp_mss_split_point(const struct sock *sk,
@@ -1966,12 +1992,14 @@ static int tcp_mtu_probe(struct sock *sk)
 	len = 0;
 	tcp_for_write_queue_from_safe(skb, next, sk) {
 		copy = min_t(int, skb->len, probe_size - len);
-		if (nskb->ip_summed)
+		if (nskb->ip_summed) {
 			skb_copy_bits(skb, 0, skb_put(nskb, copy), copy);
-		else
-			nskb->csum = skb_copy_and_csum_bits(skb, 0,
-							    skb_put(nskb, copy),
-							    copy, nskb->csum);
+		} else {
+			__wsum csum = skb_copy_and_csum_bits(skb, 0,
+							     skb_put(nskb, copy),
+							     copy, 0);
+			nskb->csum = csum_block_add(nskb->csum, csum, len);
+		}
 
 		if (skb->len <= copy) {
 			/* We've eaten all the data from this skb.
@@ -2020,6 +2048,39 @@ static int tcp_mtu_probe(struct sock *sk)
 	return -1;
 }
 
+/* TCP Small Queues :
+ * Control number of packets in qdisc/devices to two packets / or ~1 ms.
+ * (These limits are doubled for retransmits)
+ * This allows for :
+ *  - better RTT estimation and ACK scheduling
+ *  - faster recovery
+ *  - high rates
+ * Alas, some drivers / subsystems require a fair amount
+ * of queued bytes to ensure line rate.
+ * One example is wifi aggregation (802.11 AMPDU)
+ */
+static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
+				  unsigned int factor)
+{
+	unsigned int limit;
+
+	limit = max(2 * skb->truesize, sk->sk_pacing_rate >> 10);
+	limit = min_t(u32, limit, sysctl_tcp_limit_output_bytes);
+	limit <<= factor;
+
+	if (atomic_read(&sk->sk_wmem_alloc) > limit) {
+		set_bit(TSQ_THROTTLED, &tcp_sk(sk)->tsq_flags);
+		/* It is possible TX completion already happened
+		 * before we set TSQ_THROTTLED, so we must
+		 * test again the condition.
+		 */
+		smp_mb__after_atomic();
+		if (atomic_read(&sk->sk_wmem_alloc) > limit)
+			return true;
+	}
+	return false;
+}
+
 /* This routine writes packets to the network.  It advances the
  * send_head.  This happens as incoming acks open up the remote
  * window for us.
@@ -2057,7 +2118,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 		}
 	}
 
-	max_segs = tcp_tso_autosize(sk, mss_now);
+	max_segs = tcp_tso_segs(sk, mss_now);
 	while ((skb = tcp_send_head(sk))) {
 		unsigned int limit;
 
@@ -2106,29 +2167,8 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 		    unlikely(tso_fragment(sk, skb, limit, mss_now, gfp)))
 			break;
 
-		/* TCP Small Queues :
-		 * Control number of packets in qdisc/devices to two packets / or ~1 ms.
-		 * This allows for :
-		 *  - better RTT estimation and ACK scheduling
-		 *  - faster recovery
-		 *  - high rates
-		 * Alas, some drivers / subsystems require a fair amount
-		 * of queued bytes to ensure line rate.
-		 * One example is wifi aggregation (802.11 AMPDU)
-		 */
-		limit = max(2 * skb->truesize, sk->sk_pacing_rate >> 10);
-		limit = min_t(u32, limit, sysctl_tcp_limit_output_bytes);
-
-		if (atomic_read(&sk->sk_wmem_alloc) > limit) {
-			set_bit(TSQ_THROTTLED, &tp->tsq_flags);
-			/* It is possible TX completion already happened
-			 * before we set TSQ_THROTTLED, so we must
-			 * test again the condition.
-			 */
-			smp_mb__after_atomic();
-			if (atomic_read(&sk->sk_wmem_alloc) > limit)
-				break;
-		}
+		if (tcp_small_queue_check(sk, skb, 0))
+			break;
 
 		if (unlikely(tcp_transmit_skb(sk, skb, 1, gfp)))
 			break;
@@ -2605,7 +2645,8 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
 	 * copying overhead: fragmentation, tunneling, mangling etc.
 	 */
 	if (atomic_read(&sk->sk_wmem_alloc) >
-	    min(sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2), sk->sk_sndbuf))
+	    min_t(u32, sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2),
+		  sk->sk_sndbuf))
 		return -EAGAIN;
 
 	if (skb_still_in_host_queue(sk, skb))
@@ -2774,7 +2815,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk)
 		last_lost = tp->snd_una;
 	}
 
-	max_segs = tcp_tso_autosize(sk, tcp_current_mss(sk));
+	max_segs = tcp_tso_segs(sk, tcp_current_mss(sk));
 	tcp_for_write_queue_from(skb, sk) {
 		__u8 sacked;
 		int segs;
@@ -2828,10 +2869,13 @@ begin_fwd:
 		if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
 			continue;
 
+		if (tcp_small_queue_check(sk, skb, 1))
+			return;
+
 		if (tcp_retransmit_skb(sk, skb, segs))
 			return;
 
-		NET_INC_STATS(sock_net(sk), mib_idx);
+		NET_ADD_STATS(sock_net(sk), mib_idx, tcp_skb_pcount(skb));
 
 		if (tcp_in_cwnd_reduction(sk))
 			tp->prr_out += tcp_skb_pcount(skb);
@@ -3568,6 +3612,8 @@ int tcp_rtx_synack(const struct sock *sk, struct request_sock *req)
 	if (!res) {
 		__TCP_INC_STATS(sock_net(sk), TCP_MIB_RETRANSSEGS);
 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSYNRETRANS);
+		if (unlikely(tcp_passive_fastopen(sk)))
+			tcp_sk(sk)->total_retrans++;
 	}
 	return res;
 }