tcp: early retransmit: tcp_enter_recovery()
This a prepartion patch that refactors the code to enter recovery
into a new function tcp_enter_recovery(). It's needed to implement
the delayed fast retransmit in ER.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 96a631d..be8e09d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3022,6 +3022,38 @@
tp->snd_cwnd = tcp_packets_in_flight(tp) + sndcnt;
}
+static void tcp_enter_recovery(struct sock *sk, bool ece_ack)
+{
+ struct tcp_sock *tp = tcp_sk(sk);
+ int mib_idx;
+
+ if (tcp_is_reno(tp))
+ mib_idx = LINUX_MIB_TCPRENORECOVERY;
+ else
+ mib_idx = LINUX_MIB_TCPSACKRECOVERY;
+
+ NET_INC_STATS_BH(sock_net(sk), mib_idx);
+
+ tp->high_seq = tp->snd_nxt;
+ tp->prior_ssthresh = 0;
+ tp->undo_marker = tp->snd_una;
+ tp->undo_retrans = tp->retrans_out;
+
+ if (inet_csk(sk)->icsk_ca_state < TCP_CA_CWR) {
+ if (!ece_ack)
+ tp->prior_ssthresh = tcp_current_ssthresh(sk);
+ tp->snd_ssthresh = inet_csk(sk)->icsk_ca_ops->ssthresh(sk);
+ TCP_ECN_queue_cwr(tp);
+ }
+
+ tp->bytes_acked = 0;
+ tp->snd_cwnd_cnt = 0;
+ tp->prior_cwnd = tp->snd_cwnd;
+ tp->prr_delivered = 0;
+ tp->prr_out = 0;
+ tcp_set_ca_state(sk, TCP_CA_Recovery);
+}
+
/* Process an event, which can update packets-in-flight not trivially.
* Main goal of this function is to calculate new estimate for left_out,
* taking into account both packets sitting in receiver's buffer and
@@ -3041,7 +3073,7 @@
struct tcp_sock *tp = tcp_sk(sk);
int do_lost = is_dupack || ((flag & FLAG_DATA_SACKED) &&
(tcp_fackets_out(tp) > tp->reordering));
- int fast_rexmit = 0, mib_idx;
+ int fast_rexmit = 0;
if (WARN_ON(!tp->packets_out && tp->sacked_out))
tp->sacked_out = 0;
@@ -3142,32 +3174,7 @@
}
/* Otherwise enter Recovery state */
-
- if (tcp_is_reno(tp))
- mib_idx = LINUX_MIB_TCPRENORECOVERY;
- else
- mib_idx = LINUX_MIB_TCPSACKRECOVERY;
-
- NET_INC_STATS_BH(sock_net(sk), mib_idx);
-
- tp->high_seq = tp->snd_nxt;
- tp->prior_ssthresh = 0;
- tp->undo_marker = tp->snd_una;
- tp->undo_retrans = tp->retrans_out;
-
- if (icsk->icsk_ca_state < TCP_CA_CWR) {
- if (!(flag & FLAG_ECE))
- tp->prior_ssthresh = tcp_current_ssthresh(sk);
- tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk);
- TCP_ECN_queue_cwr(tp);
- }
-
- tp->bytes_acked = 0;
- tp->snd_cwnd_cnt = 0;
- tp->prior_cwnd = tp->snd_cwnd;
- tp->prr_delivered = 0;
- tp->prr_out = 0;
- tcp_set_ca_state(sk, TCP_CA_Recovery);
+ tcp_enter_recovery(sk, (flag & FLAG_ECE));
fast_rexmit = 1;
}