Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 797108d1 authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by David S. Miller
Browse files

tcp: add helper for counter tweaking due mid-wq change 



We need full-scale adjustment to fix a TCP miscount in the next
patch, so just move it into a helper and call for that from the
other places.

Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0de8ca59

include/net/tcp.h

+0 −15
Original line number Diff line number Diff line
@@ -616,21 +616,6 @@ static inline int tcp_skb_mss(const struct sk_buff *skb) 
	return skb_shinfo(skb)->gso_size;

}



static inline void tcp_dec_pcount_approx_int(__u32 *count, const int decr)

{

	if (*count) {

		*count -= decr;

		if ((int)*count < 0)

			*count = 0;

	}

}



static inline void tcp_dec_pcount_approx(__u32 *count,

					 const struct sk_buff *skb)

{

	tcp_dec_pcount_approx_int(count, tcp_skb_pcount(skb));

}



/* Events passed to congestion control interface */

enum tcp_ca_event {

	CA_EVENT_TX_START,	/* first transmit when no packets in flight */

net/ipv4/tcp_output.c

+34 −32
Original line number Diff line number Diff line
@@ -754,6 +754,36 @@ static void tcp_adjust_fackets_out(struct sock *sk, struct sk_buff *skb, 
		tp->fackets_out -= decr;

}



/* Pcount in the middle of the write queue got changed, we need to do various

 * tweaks to fix counters

 */

static void tcp_adjust_pcount(struct sock *sk, struct sk_buff *skb, int decr)

{

	struct tcp_sock *tp = tcp_sk(sk);



	tp->packets_out -= decr;



	if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)

		tp->sacked_out -= decr;

	if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)

		tp->retrans_out -= decr;

	if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST)

		tp->lost_out -= decr;



	/* Reno case is special. Sigh... */

	if (tcp_is_reno(tp) && decr > 0)

		tp->sacked_out -= min_t(u32, tp->sacked_out, decr);



	tcp_adjust_fackets_out(sk, skb, decr);



	if (tp->lost_skb_hint &&

	    before(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(tp->lost_skb_hint)->seq) &&

	    (tcp_is_fack(tp) || TCP_SKB_CB(skb)->sacked))

		tp->lost_cnt_hint -= decr;



	tcp_verify_left_out(tp);

}



/* Function to create two new TCP segments.  Shrinks the given segment

 * to the specified size and appends a new segment with the rest of the

 * packet to the list.  This won't be called frequently, I hope.
@@ -836,28 +866,8 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len, 
		int diff = old_factor - tcp_skb_pcount(skb) -

			tcp_skb_pcount(buff);



		tp->packets_out -= diff;



		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)

			tp->sacked_out -= diff;

		if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS)

			tp->retrans_out -= diff;



		if (TCP_SKB_CB(skb)->sacked & TCPCB_LOST)

			tp->lost_out -= diff;



		/* Adjust Reno SACK estimate. */

		if (tcp_is_reno(tp) && diff > 0) {

			tcp_dec_pcount_approx_int(&tp->sacked_out, diff);

			tcp_verify_left_out(tp);

		}

		tcp_adjust_fackets_out(sk, skb, diff);



		if (tp->lost_skb_hint &&

		    before(TCP_SKB_CB(skb)->seq,

			   TCP_SKB_CB(tp->lost_skb_hint)->seq) &&

		    (tcp_is_fack(tp) || TCP_SKB_CB(skb)->sacked))

			tp->lost_cnt_hint -= diff;

		if (diff)

			tcp_adjust_pcount(sk, skb, diff);

	}



	/* Link BUFF into the send queue. */
@@ -1768,22 +1778,14 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb) 
	 * packet counting does not break.

	 */

	TCP_SKB_CB(skb)->sacked |= TCP_SKB_CB(next_skb)->sacked & TCPCB_EVER_RETRANS;

	if (TCP_SKB_CB(next_skb)->sacked & TCPCB_SACKED_RETRANS)

		tp->retrans_out -= tcp_skb_pcount(next_skb);

	if (TCP_SKB_CB(next_skb)->sacked & TCPCB_LOST)

		tp->lost_out -= tcp_skb_pcount(next_skb);

	/* Reno case is special. Sigh... */

	if (tcp_is_reno(tp) && tp->sacked_out)

		tcp_dec_pcount_approx(&tp->sacked_out, next_skb);



	tcp_adjust_fackets_out(sk, next_skb, tcp_skb_pcount(next_skb));

	tp->packets_out -= tcp_skb_pcount(next_skb);



	/* changed transmit queue under us so clear hints */

	tcp_clear_retrans_hints_partial(tp);

	if (next_skb == tp->retransmit_skb_hint)

		tp->retransmit_skb_hint = skb;



	tcp_adjust_pcount(sk, next_skb, tcp_skb_pcount(next_skb));



	sk_wmem_free_skb(sk, next_skb);

}