[Patch net-next 2/3] tcp: make tcp_send_loss_probe() boolean

[Cong Wang]

Let tcp_send_loss_probe() return whether a TLP has been
sent or not. This is needed by the folllowing patch.

Cc: Eric Dumazet <eduma...@google.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
 include/net/tcp.h     | 2 +-
 net/ipv4/tcp_output.c | 7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index ab4eb5eb5d07..0ee5400e751c 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -581,7 +581,7 @@ void tcp_push_one(struct sock *, unsigned int mss_now);
 void __tcp_send_ack(struct sock *sk, u32 rcv_nxt);
 void tcp_send_ack(struct sock *sk);
 void tcp_send_delayed_ack(struct sock *sk);
-void tcp_send_loss_probe(struct sock *sk);
+bool tcp_send_loss_probe(struct sock *sk);
 bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto);
 void tcp_skb_collapse_tstamp(struct sk_buff *skb,
                             const struct sk_buff *next_skb);
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 0488607c5cd3..9822820edca4 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2539,12 +2539,13 @@ static bool skb_still_in_host_queue(const struct sock 
*sk,
 /* When probe timeout (PTO) fires, try send a new segment if possible, else
  * retransmit the last segment.
  */
-void tcp_send_loss_probe(struct sock *sk)
+bool tcp_send_loss_probe(struct sock *sk)
 {
        struct tcp_sock *tp = tcp_sk(sk);
        struct sk_buff *skb;
        int pcount;
        int mss = tcp_current_mss(sk);
+       bool sent = false;
 
        skb = tcp_send_head(sk);
        if (skb && tcp_snd_wnd_test(tp, skb, mss)) {
@@ -2560,7 +2561,7 @@ void tcp_send_loss_probe(struct sock *sk)
                          "invalid inflight: %u state %u cwnd %u mss %d\n",
                          tp->packets_out, sk->sk_state, tp->snd_cwnd, mss);
                inet_csk(sk)->icsk_pending = 0;
-               return;
+               return false;
        }
 
        /* At most one outstanding TLP retransmission. */
@@ -2592,11 +2593,13 @@ void tcp_send_loss_probe(struct sock *sk)
        tp->tlp_high_seq = tp->snd_nxt;
 
 probe_sent:
+       sent = true;
        NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPLOSSPROBES);
        /* Reset s.t. tcp_rearm_rto will restart timer from now */
        inet_csk(sk)->icsk_pending = 0;
 rearm_timer:
        tcp_rearm_rto(sk);
+       return sent;
 }
 
 /* Push out any pending frames which were held back due to
-- 
2.21.0