net_sched: gred: fix qave reporting via netlink

q->vars.qavg is a Wlog scaled value, but q->backlog is not. In order
to pass q->vars.qavg as the backlog value, we need to un-scale it.
Additionally, the qave value returned via netlink should not be Wlog
scaled, so we need to un-scale the result of red_calc_qavg().

This caused artificially high values for "Average Queue" to be shown
by 'tc -s -d qdisc', but did not affect the actual operation of GRED.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_gred.c

@@ -534,6 +534,7 @@ static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
 	for (i = 0; i < MAX_DPs; i++) {
 		struct gred_sched_data *q = table->tab[i];
 		struct tc_gred_qopt opt;
+		unsigned long qavg;
 
 		memset(&opt, 0, sizeof(opt));
 
@@ -565,7 +566,9 @@ static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
 		if (gred_wred_mode(table))
 			gred_load_wred_set(table, q);
 
-		opt.qave = red_calc_qavg(&q->parms, &q->vars, q->vars.qavg);
+		qavg = red_calc_qavg(&q->parms, &q->vars,
+				     q->vars.qavg >> q->parms.Wlog);
+		opt.qave = qavg >> q->parms.Wlog;
 
 append_opt:
 		if (nla_append(skb, sizeof(opt), &opt) < 0)