tcp: fix xmit timer to only be reset if data ACKed/SACKed

[karo-tx-linux.git] / net / ipv4 / tcp_input.c

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b9ba8d55d8b8ef3ec38274bcaac0c6500c199594..53de1424c13cda5d1fec826b97cacf4f95adc99a 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -107,6 +107,7 @@ int sysctl_tcp_invalid_ratelimit __read_mostly = HZ/2;
 #define FLAG_ORIG_SACK_ACKED   0x200 /* Never retransmitted data are (s)acked  */
 #define FLAG_SND_UNA_ADVANCED  0x400 /* Snd_una was changed (!= FLAG_DATA_ACKED) */
 #define FLAG_DSACKING_ACK      0x800 /* SACK blocks contained D-SACK info */
+#define FLAG_SET_XMIT_TIMER    0x1000 /* Set TLP or RTO timer */
 #define FLAG_SACK_RENEGING     0x2000 /* snd_una advanced to a sacked seq */
 #define FLAG_UPDATE_TS_RECENT  0x4000 /* tcp_replace_ts_recent() */
 #define FLAG_NO_CHALLENGE_ACK  0x8000 /* do not call tcp_send_challenge_ack()  */
@@ -3016,6 +3017,13 @@ void tcp_rearm_rto(struct sock *sk)
        }
 }
 
+/* Try to schedule a loss probe; if that doesn't work, then schedule an RTO. */
+static void tcp_set_xmit_timer(struct sock *sk)
+{
+       if (!tcp_schedule_loss_probe(sk))
+               tcp_rearm_rto(sk);
+}
+
 /* If we get here, the whole TSO packet has not been acked. */
 static u32 tcp_tso_acked(struct sock *sk, struct sk_buff *skb)
 {
@@ -3177,7 +3185,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
                                        ca_rtt_us, sack->rate);
 
        if (flag & FLAG_ACKED) {
-               tcp_rearm_rto(sk);
+               flag |= FLAG_SET_XMIT_TIMER;  /* set TLP or RTO timer */
                if (unlikely(icsk->icsk_mtup.probe_size &&
                             !after(tp->mtu_probe.probe_seq_end, tp->snd_una))) {
                        tcp_mtup_probe_success(sk);
@@ -3205,7 +3213,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
                 * after when the head was last (re)transmitted. Otherwise the
                 * timeout may continue to extend in loss recovery.
                 */
-               tcp_rearm_rto(sk);
+               flag |= FLAG_SET_XMIT_TIMER;  /* set TLP or RTO timer */
        }
 
        if (icsk->icsk_ca_ops->pkts_acked) {
@@ -3577,9 +3585,6 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
        if (after(ack, tp->snd_nxt))
                goto invalid_ack;
 
-       if (icsk->icsk_pending == ICSK_TIME_LOSS_PROBE)
-               tcp_rearm_rto(sk);
-
        if (after(ack, prior_snd_una)) {
                flag |= FLAG_SND_UNA_ADVANCED;
                icsk->icsk_retransmits = 0;
@@ -3644,18 +3649,20 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
        flag |= tcp_clean_rtx_queue(sk, prior_fackets, prior_snd_una, &acked,
                                    &sack_state);
 
+       if (tp->tlp_high_seq)
+               tcp_process_tlp_ack(sk, ack, flag);
+       /* If needed, reset TLP/RTO timer; RACK may later override this. */
+       if (flag & FLAG_SET_XMIT_TIMER)
+               tcp_set_xmit_timer(sk);
+
        if (tcp_ack_is_dubious(sk, flag)) {
                is_dupack = !(flag & (FLAG_SND_UNA_ADVANCED | FLAG_NOT_DUP));
                tcp_fastretrans_alert(sk, acked, is_dupack, &flag, &rexmit);
        }
-       if (tp->tlp_high_seq)
-               tcp_process_tlp_ack(sk, ack, flag);
 
        if ((flag & FLAG_FORWARD_PROGRESS) || !(flag & FLAG_NOT_DUP))
                sk_dst_confirm(sk);
 
-       if (icsk->icsk_pending == ICSK_TIME_RETRANS)
-               tcp_schedule_loss_probe(sk);
        delivered = tp->delivered - delivered;  /* freshly ACKed or SACKed */
        lost = tp->lost - lost;                 /* freshly marked lost */
        tcp_rate_gen(sk, delivered, lost, sack_state.rate);