[Patch net] sch_hfsc: always keep backlog updated

[Cong Wang]

hfsc updates backlog lazily, that is only when we
dump the stats. This is problematic after we begin to
update backlog in qdisc_tree_reduce_backlog().

Reported-by: Stas Nichiporovich <stas...@gmail.com>
Tested-by: Stas Nichiporovich <stas...@gmail.com>
Fixes: 2ccccf5fb43f ("net_sched: update hierarchical backlog too")
Cc: Jamal Hadi Salim <j...@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
---
 net/sched/sch_hfsc.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index d783d7c..1ac9f9f 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1529,6 +1529,7 @@ hfsc_reset_qdisc(struct Qdisc *sch)
        q->eligible = RB_ROOT;
        INIT_LIST_HEAD(&q->droplist);
        qdisc_watchdog_cancel(&q->watchdog);
+       sch->qstats.backlog = 0;
        sch->q.qlen = 0;
 }
 
@@ -1559,14 +1560,6 @@ hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
        struct hfsc_sched *q = qdisc_priv(sch);
        unsigned char *b = skb_tail_pointer(skb);
        struct tc_hfsc_qopt qopt;
-       struct hfsc_class *cl;
-       unsigned int i;
-
-       sch->qstats.backlog = 0;
-       for (i = 0; i < q->clhash.hashsize; i++) {
-               hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
-                       sch->qstats.backlog += cl->qdisc->qstats.backlog;
-       }
 
        qopt.defcls = q->defcls;
        if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
@@ -1604,6 +1597,7 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
        if (cl->qdisc->q.qlen == 1)
                set_active(cl, qdisc_pkt_len(skb));
 
+       qdisc_qstats_backlog_inc(sch, skb);
        sch->q.qlen++;
 
        return NET_XMIT_SUCCESS;
@@ -1672,6 +1666,7 @@ hfsc_dequeue(struct Qdisc *sch)
 
        qdisc_unthrottled(sch);
        qdisc_bstats_update(sch, skb);
+       qdisc_qstats_backlog_dec(sch, skb);
        sch->q.qlen--;
 
        return skb;
@@ -1695,6 +1690,7 @@ hfsc_drop(struct Qdisc *sch)
                        }
                        cl->qstats.drops++;
                        qdisc_qstats_drop(sch);
+                       sch->qstats.backlog -= len;
                        sch->q.qlen--;
                        return len;
                }
-- 
2.1.0