From 98fa6271cfcb1de873b3fe0caf48d9daa1bcc0ac Mon Sep 17 00:00:00 2001
From: Yuchung Cheng <ycheng@google.com>
Date: Mon, 29 Apr 2019 15:46:20 -0700
Subject: [PATCH] tcp: refactor setting the initial congestion window
Relocate the congestion window initialization from tcp_init_metrics()
to tcp_init_transfer() to improve code readability.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/tcp.c | 12 ------------
net/ipv4/tcp_input.c | 26 ++++++++++++++++++++++++++
net/ipv4/tcp_metrics.c | 10 ----------
3 files changed, 26 insertions(+), 22 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f7567a3698eb4..1fa15beb83806 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -457,18 +457,6 @@ void tcp_init_sock(struct sock *sk)
}
EXPORT_SYMBOL(tcp_init_sock);
-void tcp_init_transfer(struct sock *sk, int bpf_op)
-{
- struct inet_connection_sock *icsk = inet_csk(sk);
-
- tcp_mtup_init(sk);
- icsk->icsk_af_ops->rebuild_header(sk);
- tcp_init_metrics(sk);
- tcp_call_bpf(sk, bpf_op, 0, NULL);
- tcp_init_congestion_control(sk);
- tcp_init_buffer_space(sk);
-}
-
static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
{
struct sk_buff *skb = tcp_write_queue_tail(sk);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 706a99ec73f6f..077d9abdfcf50 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5647,6 +5647,32 @@ discard:
}
EXPORT_SYMBOL(tcp_rcv_established);
+void tcp_init_transfer(struct sock *sk, int bpf_op)
+{
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
+
+ tcp_mtup_init(sk);
+ icsk->icsk_af_ops->rebuild_header(sk);
+ tcp_init_metrics(sk);
+
+ /* Initialize the congestion window to start the transfer.
+ * Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been
+ * retransmitted. In light of RFC6298 more aggressive 1sec
+ * initRTO, we only reset cwnd when more than 1 SYN/SYN-ACK
+ * retransmission has occurred.
+ */
+ if (tp->total_retrans > 1 && tp->undo_marker)
+ tp->snd_cwnd = 1;
+ else
+ tp->snd_cwnd = tcp_init_cwnd(tp, __sk_dst_get(sk));
+ tp->snd_cwnd_stamp = tcp_jiffies32;
+
+ tcp_call_bpf(sk, bpf_op, 0, NULL);
+ tcp_init_congestion_control(sk);
+ tcp_init_buffer_space(sk);
+}
+
void tcp_finish_connect(struct sock *sk, struct sk_buff *skb)
{
struct tcp_sock *tp = tcp_sk(sk);
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index d4d687330e2ba..c4848e7a0aad1 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -512,16 +512,6 @@ reset:
inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK;
}
- /* Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been
- * retransmitted. In light of RFC6298 more aggressive 1sec
- * initRTO, we only reset cwnd when more than 1 SYN/SYN-ACK
- * retransmission has occurred.
- */
- if (tp->total_retrans > 1 && tp->undo_marker)
- tp->snd_cwnd = 1;
- else
- tp->snd_cwnd = tcp_init_cwnd(tp, dst);
- tp->snd_cwnd_stamp = tcp_jiffies32;
}
bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst)
--
2.30.2