diff --git a/include/net/tcp.h b/include/net/tcp.h index a88bf8f6db23..9cbcfb3c95da 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -723,6 +723,8 @@ static inline void tcp_fast_path_check(struct sock *sk) tcp_fast_path_on(tp); } +u32 tcp_delack_max(const struct sock *sk); + /* Compute the actual rto_min value */ static inline u32 tcp_rto_min(struct sock *sk) { diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index ec46d74c2093..f124f6c63915 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3774,7 +3774,8 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info) info->tcpi_options |= TCPI_OPT_SYN_DATA; info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto); - info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato); + info->tcpi_ato = jiffies_to_usecs(min(icsk->icsk_ack.ato, + tcp_delack_max(sk))); info->tcpi_snd_mss = tp->mss_cache; info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index cab3c1162c3a..ab3b7b4b4429 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -4003,6 +4003,20 @@ int tcp_connect(struct sock *sk) } EXPORT_SYMBOL(tcp_connect); +u32 tcp_delack_max(const struct sock *sk) +{ + const struct dst_entry *dst = __sk_dst_get(sk); + u32 delack_max = inet_csk(sk)->icsk_delack_max; + + if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) { + u32 rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); + u32 delack_from_rto_min = max_t(int, 1, rto_min - 1); + + delack_max = min_t(u32, delack_max, delack_from_rto_min); + } + return delack_max; +} + /* Send out a delayed ack, the caller does the policy checking * to see if we should even be here. See tcp_input.c:tcp_ack_snd_check() * for details. @@ -4038,7 +4052,7 @@ void tcp_send_delayed_ack(struct sock *sk) ato = min(ato, max_ato); } - ato = min_t(u32, ato, inet_csk(sk)->icsk_delack_max); + ato = min_t(u32, ato, tcp_delack_max(sk)); /* Stay within the limit we were given */ timeout = jiffies + ato;