sack_newdata and snd_recover hold the same value. Therefore, use only

a single instance: use snd_recover also where sack_newdata was used.

Submitted by:		Richard Scheffenegger
Differential Revision:	https://reviews.freebsd.org/D18811

cddl/lib/libdtrace/tcp.d

@@ -244,7 +244,7 @@ translator tcpsinfo_t < struct tcpcb *p > {
 	tcps_cwnd_ssthresh =	p == NULL ? -1 : p->snd_ssthresh;
 	tcps_srecover =		p == NULL ? -1 : p->snd_recover;
 	tcps_sack_fack =	p == NULL ? 0  : p->snd_fack;
-	tcps_sack_snxt =	p == NULL ? 0  : p->sack_newdata;
+	tcps_sack_snxt =	p == NULL ? 0  : p->snd_recover;
 	tcps_rto =		p == NULL ? -1 : (p->t_rxtcur * 1000) / `hz;
 	tcps_mss =		p == NULL ? -1 : p->t_maxseg;
 	tcps_retransmit =	p == NULL ? -1 : p->t_rxtshift > 0 ? 1 : 0;

sys/netinet/tcp_input.c

@@ -2564,7 +2564,7 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
 					if (tp->t_flags & TF_SACK_PERMIT) {
 						TCPSTAT_INC(
 						    tcps_sack_recovery_episode);
-						tp->sack_newdata = tp->snd_nxt;
+						tp->snd_recover = tp->snd_nxt;
 						tp->snd_cwnd = maxseg;
 						(void) tp->t_fb->tfb_tcp_output(tp);
 						goto drop;

sys/netinet/tcp_log_buf.c

@@ -1686,7 +1686,6 @@ tcp_log_event_(struct tcpcb *tp, struct tcphdr *th, struct sockbuf *rxbuf,
 	COPY_STAT(rcv_up);
 	COPY_STAT(rcv_adv);
 	COPY_STAT(rcv_nxt);
-	COPY_STAT(sack_newdata);
 	COPY_STAT(rcv_wnd);
 	COPY_STAT_T(dupacks);
 	COPY_STAT_T(segqlen);

sys/netinet/tcp_log_buf.h

@@ -32,7 +32,7 @@
 
 #define	TCP_LOG_REASON_LEN	32
 #define	TCP_LOG_TAG_LEN		32
-#define	TCP_LOG_BUF_VER		(7)
+#define	TCP_LOG_BUF_VER		(8)
 
 /*
  * Because the (struct tcp_log_buffer) includes 8-byte uint64_t's, it requires
@@ -144,7 +144,6 @@ struct tcp_log_buffer
 	uint32_t	tlb_rcv_up;	/* TCPCB rcv_up */
 	uint32_t	tlb_rcv_adv;	/* TCPCB rcv_adv */
 	uint32_t	tlb_rcv_nxt;	/* TCPCB rcv_nxt */
-	tcp_seq		tlb_sack_newdata; /* TCPCB sack_newdata */
 	uint32_t	tlb_rcv_wnd;	/* TCPCB rcv_wnd */
 	uint32_t	tlb_dupacks;	/* TCPCB t_dupacks */
 	int		tlb_segqlen;	/* TCPCB segqlen */

sys/netinet/tcp_output.c

@@ -420,7 +420,7 @@ tcp_output(struct tcpcb *tp)
 			 */
 			if (len > 0) {
 				cwin = tp->snd_cwnd -
-					(tp->snd_nxt - tp->sack_newdata) -
+					(tp->snd_nxt - tp->snd_recover) -
 					sack_bytes_rxmt;
 				if (cwin < 0)
 					cwin = 0;

sys/netinet/tcp_sack.c

@@ -780,7 +780,7 @@ tcp_sack_partialack(struct tcpcb *tp, struct tcphdr *th)
 	if ((BYTES_THIS_ACK(tp, th) / tp->t_maxseg) >= 2)
 		num_segs = 2;
 	tp->snd_cwnd = (tp->sackhint.sack_bytes_rexmit +
-	    (tp->snd_nxt - tp->sack_newdata) + num_segs * tp->t_maxseg);
+	    (tp->snd_nxt - tp->snd_recover) + num_segs * tp->t_maxseg);
 	if (tp->snd_cwnd > tp->snd_ssthresh)
 		tp->snd_cwnd = tp->snd_ssthresh;
 	tp->t_flags |= TF_ACKNOW;

sys/netinet/tcp_usrreq.c

@@ -2806,8 +2806,8 @@ db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
 	    tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
 
 	db_print_indent(indent);
-	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d   sack_newdata: "
+	db_printf("snd_fack: 0x%08x   rcv_numsacks: %d\n",
-	    "0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
+	    tp->snd_fack, tp->rcv_numsacks);
 
 	/* Skip sackblks, sackhint. */
 

sys/netinet/tcp_var.h

@@ -186,8 +186,6 @@ struct tcpcb {
 	TAILQ_HEAD(sackhole_head, sackhole) snd_holes;
 					/* SACK scoreboard (sorted) */
 	tcp_seq	snd_fack;		/* last seq number(+1) sack'd by rcv'r*/
-	tcp_seq sack_newdata;		/* New data xmitted in this recovery
-					   episode starts at this seq number */
 	struct sackblk sackblks[MAX_SACK_BLKS]; /* seq nos. of sack blocks */
 	struct sackhint	sackhint;	/* SACK scoreboard hint */
 	int	t_rttlow;		/* smallest observerved RTT */