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authorDavid S. Miller <davem@davemloft.net>2017-12-08 22:14:12 +0300
committerDavid S. Miller <davem@davemloft.net>2017-12-08 22:14:12 +0300
commitb7e445a1c8f4fb056a94dcb6accbc590aec69d19 (patch)
tree39472b7c1cc30a0ce316278fc8854101245b97b7
parent2edbdb3159d6f6bd3a9b6e7f789f2b879699a519 (diff)
parent6065fd0d179b96ddc488c76542349bcb148a95fd (diff)
downloadlinux-b7e445a1c8f4fb056a94dcb6accbc590aec69d19.tar.xz
Merge branch 'tcp-RACK-loss-recovery-bug-fixes'
Yuchung Cheng says: ==================== tcp: RACK loss recovery bug fixes This patch set has four minor bug fixes in TCP RACK loss recovery. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv4/tcp_input.c1
-rw-r--r--net/ipv4/tcp_recovery.c28
2 files changed, 14 insertions, 15 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 075c559570e6..9550cc42de2d 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2329,6 +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)
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