Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Conflict was two parallel additions of include files to sch_generic.c,
no biggie.

Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 44 insertions, 25 deletions

diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index c690cd0d9b3f..b563e0c46bac 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -93,7 +93,7 @@ static void inet_twsk_add_bind_node(struct inet_timewait_sock *tw,
 }
 
 /*
- * Enter the time wait state.
+ * Enter the time wait state. This is called with locally disabled BH.
  * Essentially we whip up a timewait bucket, copy the relevant info into it
  * from the SK, and mess with hash chains and list linkage.
  */
@@ -111,7 +111,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
 	 */
 	bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), inet->inet_num,
 			hashinfo->bhash_size)];
-	spin_lock_bh(&bhead->lock);
+	spin_lock(&bhead->lock);
 	tw->tw_tb = icsk->icsk_bind_hash;
 	WARN_ON(!icsk->icsk_bind_hash);
 	inet_twsk_add_bind_node(tw, &tw->tw_tb->owners);
@@ -137,7 +137,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
 	if (__sk_nulls_del_node_init_rcu(sk))
 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 
-	spin_unlock_bh(lock);
+	spin_unlock(lock);
 }
 EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
 
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 180311636023..c470fec9062f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2412,6 +2412,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 	tp->snd_cwnd_cnt = 0;
 	tp->window_clamp = 0;
 	tcp_set_ca_state(sk, TCP_CA_Open);
+	tp->is_sack_reneg = 0;
 	tcp_clear_retrans(tp);
 	inet_csk_delack_init(sk);
 	/* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0
diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
index 69ee877574d0..8322f26e770e 100644
--- a/net/ipv4/tcp_bbr.c
+++ b/net/ipv4/tcp_bbr.c
@@ -110,7 +110,8 @@ struct bbr {
 	u32	lt_last_lost;	     /* LT intvl start: tp->lost */
 	u32	pacing_gain:10,	/* current gain for setting pacing rate */
 		cwnd_gain:10,	/* current gain for setting cwnd */
-		full_bw_cnt:3,	/* number of rounds without large bw gains */
+		full_bw_reached:1,   /* reached full bw in Startup? */
+		full_bw_cnt:2,	/* number of rounds without large bw gains */
 		cycle_idx:3,	/* current index in pacing_gain cycle array */
 		has_seen_rtt:1, /* have we seen an RTT sample yet? */
 		unused_b:5;
@@ -180,7 +181,7 @@ static bool bbr_full_bw_reached(const struct sock *sk)
 {
 	const struct bbr *bbr = inet_csk_ca(sk);
 
-	return bbr->full_bw_cnt >= bbr_full_bw_cnt;
+	return bbr->full_bw_reached;
 }
 
 /* Return the windowed max recent bandwidth sample, in pkts/uS << BW_SCALE. */
@@ -717,6 +718,7 @@ static void bbr_check_full_bw_reached(struct sock *sk,
 		return;
 	}
 	++bbr->full_bw_cnt;
+	bbr->full_bw_reached = bbr->full_bw_cnt >= bbr_full_bw_cnt;
 }
 
 /* If pipe is probably full, drain the queue and then enter steady-state. */
@@ -850,6 +852,7 @@ static void bbr_init(struct sock *sk)
 	bbr->restore_cwnd = 0;
 	bbr->round_start = 0;
 	bbr->idle_restart = 0;
+	bbr->full_bw_reached = 0;
 	bbr->full_bw = 0;
 	bbr->full_bw_cnt = 0;
 	bbr->cycle_mstamp = 0;
@@ -871,6 +874,11 @@ static u32 bbr_sndbuf_expand(struct sock *sk)
  */
 static u32 bbr_undo_cwnd(struct sock *sk)
 {
+	struct bbr *bbr = inet_csk_ca(sk);
+
+	bbr->full_bw = 0;   /* spurious slow-down; reset full pipe detection */
+	bbr->full_bw_cnt = 0;
+	bbr_reset_lt_bw_sampling(sk);
 	return tcp_sk(sk)->snd_cwnd;
 }
 
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 734cfc8ff76e..9550cc42de2d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -579,6 +579,7 @@ void tcp_rcv_space_adjust(struct sock *sk)
 	int time;
 	int copied;
 
+	tcp_mstamp_refresh(tp);
 	time = tcp_stamp_us_delta(tp->tcp_mstamp, tp->rcvq_space.time);
 	if (time < (tp->rcv_rtt_est.rtt_us >> 3) || tp->rcv_rtt_est.rtt_us == 0)
 		return;
@@ -1941,6 +1942,8 @@ void tcp_enter_loss(struct sock *sk)
 	if (is_reneg) {
 		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSACKRENEGING);
 		tp->sacked_out = 0;
+		/* Mark SACK reneging until we recover from this loss event. */
+		tp->is_sack_reneg = 1;
 	}
 	tcp_clear_all_retrans_hints(tp);
 
@@ -2326,6 +2329,7 @@ static void tcp_undo_cwnd_reduction(struct sock *sk, bool unmark_loss)
 	}
 	tp->snd_cwnd_stamp = tcp_jiffies32;
 	tp->undo_marker = 0;
+	tp->rack.advanced = 1; /* Force RACK to re-exam losses */
 }
 
 static inline bool tcp_may_undo(const struct tcp_sock *tp)
@@ -2364,6 +2368,7 @@ static bool tcp_try_undo_recovery(struct sock *sk)
 		return true;
 	}
 	tcp_set_ca_state(sk, TCP_CA_Open);
+	tp->is_sack_reneg = 0;
 	return false;
 }
 
@@ -2397,8 +2402,10 @@ static bool tcp_try_undo_loss(struct sock *sk, bool frto_undo)
 			NET_INC_STATS(sock_net(sk),
 					LINUX_MIB_TCPSPURIOUSRTOS);
 		inet_csk(sk)->icsk_retransmits = 0;
-		if (frto_undo || tcp_is_sack(tp))
+		if (frto_undo || tcp_is_sack(tp)) {
 			tcp_set_ca_state(sk, TCP_CA_Open);
+			tp->is_sack_reneg = 0;
+		}
 		return true;
 	}
 	return false;
@@ -3495,6 +3502,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 	struct tcp_sacktag_state sack_state;
 	struct rate_sample rs = { .prior_delivered = 0 };
 	u32 prior_snd_una = tp->snd_una;
+	bool is_sack_reneg = tp->is_sack_reneg;
 	u32 ack_seq = TCP_SKB_CB(skb)->seq;
 	u32 ack = TCP_SKB_CB(skb)->ack_seq;
 	bool is_dupack = false;
@@ -3611,7 +3619,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
 
 	delivered = tp->delivered - delivered;	/* freshly ACKed or SACKed */
 	lost = tp->lost - lost;			/* freshly marked lost */
-	tcp_rate_gen(sk, delivered, lost, sack_state.rate);
+	tcp_rate_gen(sk, delivered, lost, is_sack_reneg, sack_state.rate);
 	tcp_cong_control(sk, ack, delivered, flag, sack_state.rate);
 	tcp_xmit_recovery(sk, rexmit);
 	return 1;
diff --git a/net/ipv4/tcp_rate.c b/net/ipv4/tcp_rate.c
index 3330a370d306..c61240e43923 100644
--- a/net/ipv4/tcp_rate.c
+++ b/net/ipv4/tcp_rate.c
@@ -106,7 +106,7 @@ void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb,
 
 /* Update the connection delivery information and generate a rate sample. */
 void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost,
-		  struct rate_sample *rs)
+		  bool is_sack_reneg, struct rate_sample *rs)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 	u32 snd_us, ack_us;
@@ -124,8 +124,12 @@ void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost,
 
 	rs->acked_sacked = delivered;	/* freshly ACKed or SACKed */
 	rs->losses = lost;		/* freshly marked lost */
-	/* Return an invalid sample if no timing information is available. */
-	if (!rs->prior_mstamp) {
+	/* Return an invalid sample if no timing information is available or
+	 * in recovery from loss with SACK reneging. Rate samples taken during
+	 * a SACK reneging event may overestimate bw by including packets that
+	 * were SACKed before the reneg.
+	 */
+	if (!rs->prior_mstamp || is_sack_reneg) {
 		rs->delivered = -1;
 		rs->interval_us = -1;
 		return;
diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c
index d3ea89020c69..3a81720ac0c4 100644
--- a/net/ipv4/tcp_recovery.c
+++ b/net/ipv4/tcp_recovery.c
@@ -55,7 +55,8 @@ static void tcp_rack_detect_loss(struct sock *sk, u32 *reo_timeout)
 	 * to queuing or delayed ACKs.
 	 */
 	reo_wnd = 1000;
-	if ((tp->rack.reord || !tp->lost_out) && min_rtt != ~0U) {
+	if ((tp->rack.reord || inet_csk(sk)->icsk_ca_state < TCP_CA_Recovery) &&
+	    min_rtt != ~0U) {
 		reo_wnd = max((min_rtt >> 2) * tp->rack.reo_wnd_steps, reo_wnd);
 		reo_wnd = min(reo_wnd, tp->srtt_us >> 3);
 	}
@@ -79,12 +80,12 @@ static void tcp_rack_detect_loss(struct sock *sk, u32 *reo_timeout)
 		 */
 		remaining = tp->rack.rtt_us + reo_wnd -
 			    tcp_stamp_us_delta(tp->tcp_mstamp, skb->skb_mstamp);
-		if (remaining < 0) {
+		if (remaining <= 0) {
 			tcp_rack_mark_skb_lost(sk, skb);
 			list_del_init(&skb->tcp_tsorted_anchor);
 		} else {
-			/* Record maximum wait time (+1 to avoid 0) */
-			*reo_timeout = max_t(u32, *reo_timeout, 1 + remaining);
+			/* Record maximum wait time */
+			*reo_timeout = max_t(u32, *reo_timeout, remaining);
 		}
 	}
 }
@@ -116,13 +117,8 @@ void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq,
 {
 	u32 rtt_us;
 
-	if (tp->rack.mstamp &&
-	    !tcp_rack_sent_after(xmit_time, tp->rack.mstamp,
-				 end_seq, tp->rack.end_seq))
-		return;
-
 	rtt_us = tcp_stamp_us_delta(tp->tcp_mstamp, xmit_time);
-	if (sacked & TCPCB_RETRANS) {
+	if (rtt_us < tcp_min_rtt(tp) && (sacked & TCPCB_RETRANS)) {
 		/* If the sacked packet was retransmitted, it's ambiguous
 		 * whether the retransmission or the original (or the prior
 		 * retransmission) was sacked.
@@ -133,13 +129,15 @@ void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq,
 		 * so it's at least one RTT (i.e., retransmission is at least
 		 * an RTT later).
 		 */
-		if (rtt_us < tcp_min_rtt(tp))
-			return;
+		return;
 	}
-	tp->rack.rtt_us = rtt_us;
-	tp->rack.mstamp = xmit_time;
-	tp->rack.end_seq = end_seq;
 	tp->rack.advanced = 1;
+	tp->rack.rtt_us = rtt_us;
+	if (tcp_rack_sent_after(xmit_time, tp->rack.mstamp,
+				end_seq, tp->rack.end_seq)) {
+		tp->rack.mstamp = xmit_time;
+		tp->rack.end_seq = end_seq;
+	}
 }
 
 /* We have waited long enough to accommodate reordering. Mark the expired