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tcp: take care of compressed acks in tcp_add_reno_sack()
Neal pointed out that non sack flows might suffer from ACK compression added in the following patch ("tcp: implement coalescing on backlog queue") Instead of tweaking tcp_add_backlog() we can take into account how many ACK were coalesced, this information will be available in skb_shinfo(skb)->gso_segs Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
ebeef4bccc
commit
19119f298b
1 changed files with 33 additions and 25 deletions
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@ -1865,16 +1865,20 @@ static void tcp_check_reno_reordering(struct sock *sk, const int addend)
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/* Emulate SACKs for SACKless connection: account for a new dupack. */
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/* Emulate SACKs for SACKless connection: account for a new dupack. */
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static void tcp_add_reno_sack(struct sock *sk)
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static void tcp_add_reno_sack(struct sock *sk, int num_dupack)
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{
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{
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struct tcp_sock *tp = tcp_sk(sk);
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if (num_dupack) {
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u32 prior_sacked = tp->sacked_out;
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struct tcp_sock *tp = tcp_sk(sk);
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u32 prior_sacked = tp->sacked_out;
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s32 delivered;
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tp->sacked_out++;
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tp->sacked_out += num_dupack;
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tcp_check_reno_reordering(sk, 0);
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tcp_check_reno_reordering(sk, 0);
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if (tp->sacked_out > prior_sacked)
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delivered = tp->sacked_out - prior_sacked;
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tp->delivered++; /* Some out-of-order packet is delivered */
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if (delivered > 0)
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tcp_verify_left_out(tp);
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tp->delivered += delivered;
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tcp_verify_left_out(tp);
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}
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}
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}
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/* Account for ACK, ACKing some data in Reno Recovery phase. */
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/* Account for ACK, ACKing some data in Reno Recovery phase. */
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@ -2636,7 +2640,7 @@ void tcp_enter_recovery(struct sock *sk, bool ece_ack)
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/* Process an ACK in CA_Loss state. Move to CA_Open if lost data are
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/* Process an ACK in CA_Loss state. Move to CA_Open if lost data are
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* recovered or spurious. Otherwise retransmits more on partial ACKs.
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* recovered or spurious. Otherwise retransmits more on partial ACKs.
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*/
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*/
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static void tcp_process_loss(struct sock *sk, int flag, bool is_dupack,
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static void tcp_process_loss(struct sock *sk, int flag, int num_dupack,
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int *rexmit)
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int *rexmit)
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{
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{
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struct tcp_sock *tp = tcp_sk(sk);
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struct tcp_sock *tp = tcp_sk(sk);
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@ -2655,7 +2659,7 @@ static void tcp_process_loss(struct sock *sk, int flag, bool is_dupack,
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return;
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return;
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if (after(tp->snd_nxt, tp->high_seq)) {
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if (after(tp->snd_nxt, tp->high_seq)) {
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if (flag & FLAG_DATA_SACKED || is_dupack)
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if (flag & FLAG_DATA_SACKED || num_dupack)
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tp->frto = 0; /* Step 3.a. loss was real */
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tp->frto = 0; /* Step 3.a. loss was real */
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} else if (flag & FLAG_SND_UNA_ADVANCED && !recovered) {
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} else if (flag & FLAG_SND_UNA_ADVANCED && !recovered) {
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tp->high_seq = tp->snd_nxt;
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tp->high_seq = tp->snd_nxt;
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@ -2681,8 +2685,8 @@ static void tcp_process_loss(struct sock *sk, int flag, bool is_dupack,
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/* A Reno DUPACK means new data in F-RTO step 2.b above are
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/* A Reno DUPACK means new data in F-RTO step 2.b above are
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* delivered. Lower inflight to clock out (re)tranmissions.
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* delivered. Lower inflight to clock out (re)tranmissions.
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*/
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*/
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if (after(tp->snd_nxt, tp->high_seq) && is_dupack)
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if (after(tp->snd_nxt, tp->high_seq) && num_dupack)
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tcp_add_reno_sack(sk);
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tcp_add_reno_sack(sk, num_dupack);
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else if (flag & FLAG_SND_UNA_ADVANCED)
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else if (flag & FLAG_SND_UNA_ADVANCED)
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tcp_reset_reno_sack(tp);
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tcp_reset_reno_sack(tp);
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}
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}
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@ -2759,13 +2763,13 @@ static bool tcp_force_fast_retransmit(struct sock *sk)
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* tcp_xmit_retransmit_queue().
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* tcp_xmit_retransmit_queue().
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*/
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*/
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static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
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static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
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bool is_dupack, int *ack_flag, int *rexmit)
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int num_dupack, int *ack_flag, int *rexmit)
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{
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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struct inet_connection_sock *icsk = inet_csk(sk);
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struct tcp_sock *tp = tcp_sk(sk);
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struct tcp_sock *tp = tcp_sk(sk);
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int fast_rexmit = 0, flag = *ack_flag;
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int fast_rexmit = 0, flag = *ack_flag;
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bool do_lost = is_dupack || ((flag & FLAG_DATA_SACKED) &&
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bool do_lost = num_dupack || ((flag & FLAG_DATA_SACKED) &&
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tcp_force_fast_retransmit(sk));
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tcp_force_fast_retransmit(sk));
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if (!tp->packets_out && tp->sacked_out)
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if (!tp->packets_out && tp->sacked_out)
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tp->sacked_out = 0;
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tp->sacked_out = 0;
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@ -2812,8 +2816,8 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
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switch (icsk->icsk_ca_state) {
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switch (icsk->icsk_ca_state) {
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case TCP_CA_Recovery:
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case TCP_CA_Recovery:
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if (!(flag & FLAG_SND_UNA_ADVANCED)) {
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if (!(flag & FLAG_SND_UNA_ADVANCED)) {
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if (tcp_is_reno(tp) && is_dupack)
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if (tcp_is_reno(tp))
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tcp_add_reno_sack(sk);
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tcp_add_reno_sack(sk, num_dupack);
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} else {
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} else {
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if (tcp_try_undo_partial(sk, prior_snd_una))
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if (tcp_try_undo_partial(sk, prior_snd_una))
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return;
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return;
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@ -2828,7 +2832,7 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
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tcp_identify_packet_loss(sk, ack_flag);
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tcp_identify_packet_loss(sk, ack_flag);
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break;
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break;
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case TCP_CA_Loss:
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case TCP_CA_Loss:
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tcp_process_loss(sk, flag, is_dupack, rexmit);
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tcp_process_loss(sk, flag, num_dupack, rexmit);
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tcp_identify_packet_loss(sk, ack_flag);
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tcp_identify_packet_loss(sk, ack_flag);
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if (!(icsk->icsk_ca_state == TCP_CA_Open ||
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if (!(icsk->icsk_ca_state == TCP_CA_Open ||
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(*ack_flag & FLAG_LOST_RETRANS)))
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(*ack_flag & FLAG_LOST_RETRANS)))
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@ -2839,8 +2843,7 @@ static void tcp_fastretrans_alert(struct sock *sk, const u32 prior_snd_una,
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if (tcp_is_reno(tp)) {
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if (tcp_is_reno(tp)) {
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if (flag & FLAG_SND_UNA_ADVANCED)
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if (flag & FLAG_SND_UNA_ADVANCED)
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tcp_reset_reno_sack(tp);
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tcp_reset_reno_sack(tp);
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if (is_dupack)
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tcp_add_reno_sack(sk, num_dupack);
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tcp_add_reno_sack(sk);
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}
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}
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if (icsk->icsk_ca_state <= TCP_CA_Disorder)
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if (icsk->icsk_ca_state <= TCP_CA_Disorder)
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@ -3562,7 +3565,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
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bool is_sack_reneg = tp->is_sack_reneg;
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bool is_sack_reneg = tp->is_sack_reneg;
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u32 ack_seq = TCP_SKB_CB(skb)->seq;
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u32 ack_seq = TCP_SKB_CB(skb)->seq;
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u32 ack = TCP_SKB_CB(skb)->ack_seq;
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u32 ack = TCP_SKB_CB(skb)->ack_seq;
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bool is_dupack = false;
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int num_dupack = 0;
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int prior_packets = tp->packets_out;
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int prior_packets = tp->packets_out;
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u32 delivered = tp->delivered;
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u32 delivered = tp->delivered;
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u32 lost = tp->lost;
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u32 lost = tp->lost;
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@ -3673,8 +3676,13 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
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tcp_set_xmit_timer(sk);
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tcp_set_xmit_timer(sk);
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if (tcp_ack_is_dubious(sk, flag)) {
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if (tcp_ack_is_dubious(sk, flag)) {
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is_dupack = !(flag & (FLAG_SND_UNA_ADVANCED | FLAG_NOT_DUP));
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if (!(flag & (FLAG_SND_UNA_ADVANCED | FLAG_NOT_DUP))) {
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tcp_fastretrans_alert(sk, prior_snd_una, is_dupack, &flag,
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num_dupack = 1;
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/* Consider if pure acks were aggregated in tcp_add_backlog() */
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if (!(flag & FLAG_DATA))
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num_dupack = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
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}
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tcp_fastretrans_alert(sk, prior_snd_una, num_dupack, &flag,
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&rexmit);
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&rexmit);
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}
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}
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@ -3692,7 +3700,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
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no_queue:
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no_queue:
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/* If data was DSACKed, see if we can undo a cwnd reduction. */
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/* If data was DSACKed, see if we can undo a cwnd reduction. */
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if (flag & FLAG_DSACKING_ACK) {
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if (flag & FLAG_DSACKING_ACK) {
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tcp_fastretrans_alert(sk, prior_snd_una, is_dupack, &flag,
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tcp_fastretrans_alert(sk, prior_snd_una, num_dupack, &flag,
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&rexmit);
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&rexmit);
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tcp_newly_delivered(sk, delivered, flag);
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tcp_newly_delivered(sk, delivered, flag);
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}
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}
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@ -3717,7 +3725,7 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag)
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if (TCP_SKB_CB(skb)->sacked) {
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if (TCP_SKB_CB(skb)->sacked) {
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flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
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flag |= tcp_sacktag_write_queue(sk, skb, prior_snd_una,
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&sack_state);
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&sack_state);
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tcp_fastretrans_alert(sk, prior_snd_una, is_dupack, &flag,
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tcp_fastretrans_alert(sk, prior_snd_una, num_dupack, &flag,
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&rexmit);
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&rexmit);
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tcp_newly_delivered(sk, delivered, flag);
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tcp_newly_delivered(sk, delivered, flag);
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tcp_xmit_recovery(sk, rexmit);
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tcp_xmit_recovery(sk, rexmit);
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