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Commit 4ddf6676 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by David S. Miller
Browse files

[TCP]: Move Reno SACKed_out counter functions earlier 



Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d06e021d

net/ipv4/tcp_input.c

+47 −51
Original line number Diff line number Diff line
@@ -1314,6 +1314,53 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_ 
/* F-RTO can only be used if TCP has never retransmitted anything other than

 * head (SACK enhanced variant from Appendix B of RFC4138 is more robust here)

 */

static void tcp_check_reno_reordering(struct sock *sk, const int addend)

{

	struct tcp_sock *tp = tcp_sk(sk);

	u32 holes;



	holes = max(tp->lost_out, 1U);

	holes = min(holes, tp->packets_out);



	if ((tp->sacked_out + holes) > tp->packets_out) {

		tp->sacked_out = tp->packets_out - holes;

		tcp_update_reordering(sk, tp->packets_out + addend, 0);

	}

}



/* Emulate SACKs for SACKless connection: account for a new dupack. */



static void tcp_add_reno_sack(struct sock *sk)

{

	struct tcp_sock *tp = tcp_sk(sk);

	tp->sacked_out++;

	tcp_check_reno_reordering(sk, 0);

	tcp_sync_left_out(tp);

}



/* Account for ACK, ACKing some data in Reno Recovery phase. */



static void tcp_remove_reno_sacks(struct sock *sk, int acked)

{

	struct tcp_sock *tp = tcp_sk(sk);



	if (acked > 0) {

		/* One ACK acked hole. The rest eat duplicate ACKs. */

		if (acked-1 >= tp->sacked_out)

			tp->sacked_out = 0;

		else

			tp->sacked_out -= acked-1;

	}

	tcp_check_reno_reordering(sk, acked);

	tcp_sync_left_out(tp);

}



static inline void tcp_reset_reno_sack(struct tcp_sock *tp)

{

	tp->sacked_out = 0;

	tp->left_out = tp->lost_out;

}



int tcp_use_frto(struct sock *sk)

{

	const struct tcp_sock *tp = tcp_sk(sk);
@@ -1730,57 +1777,6 @@ static int tcp_time_to_recover(struct sock *sk) 
	return 0;

}



/* If we receive more dupacks than we expected counting segments

 * in assumption of absent reordering, interpret this as reordering.

 * The only another reason could be bug in receiver TCP.

 */

static void tcp_check_reno_reordering(struct sock *sk, const int addend)

{

	struct tcp_sock *tp = tcp_sk(sk);

	u32 holes;



	holes = max(tp->lost_out, 1U);

	holes = min(holes, tp->packets_out);



	if ((tp->sacked_out + holes) > tp->packets_out) {

		tp->sacked_out = tp->packets_out - holes;

		tcp_update_reordering(sk, tp->packets_out + addend, 0);

	}

}



/* Emulate SACKs for SACKless connection: account for a new dupack. */



static void tcp_add_reno_sack(struct sock *sk)

{

	struct tcp_sock *tp = tcp_sk(sk);

	tp->sacked_out++;

	tcp_check_reno_reordering(sk, 0);

	tcp_sync_left_out(tp);

}



/* Account for ACK, ACKing some data in Reno Recovery phase. */



static void tcp_remove_reno_sacks(struct sock *sk, int acked)

{

	struct tcp_sock *tp = tcp_sk(sk);



	if (acked > 0) {

		/* One ACK acked hole. The rest eat duplicate ACKs. */

		if (acked-1 >= tp->sacked_out)

			tp->sacked_out = 0;

		else

			tp->sacked_out -= acked-1;

	}

	tcp_check_reno_reordering(sk, acked);

	tcp_sync_left_out(tp);

}



static inline void tcp_reset_reno_sack(struct tcp_sock *tp)

{

	tp->sacked_out = 0;

	tp->left_out = tp->lost_out;

}



/* RFC: This is from the original, I doubt that this is necessary at all:

 * clear xmit_retrans hint if seq of this skb is beyond hint. How could we

 * retransmitted past LOST markings in the first place? I'm not fully sure