[NET_SCHED]: Fix endless loops (part 4): HTB
Convert HTB to use qdisc_tree_decrease_len() and add a callback
for deactivating a class when its child queue becomes empty.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 3b36e9d..215e68c 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1230,11 +1230,7 @@
return -ENOBUFS;
sch_tree_lock(sch);
if ((*old = xchg(&cl->un.leaf.q, new)) != NULL) {
- if (cl->prio_activity)
- htb_deactivate(qdisc_priv(sch), cl);
-
- /* TODO: is it correct ? Why CBQ doesn't do it ? */
- sch->q.qlen -= (*old)->q.qlen;
+ qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
qdisc_reset(*old);
}
sch_tree_unlock(sch);
@@ -1249,6 +1245,14 @@
return (cl && !cl->level) ? cl->un.leaf.q : NULL;
}
+static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg)
+{
+ struct htb_class *cl = (struct htb_class *)arg;
+
+ if (cl->un.leaf.q->q.qlen == 0)
+ htb_deactivate(qdisc_priv(sch), cl);
+}
+
static unsigned long htb_get(struct Qdisc *sch, u32 classid)
{
struct htb_class *cl = htb_find(classid, sch);
@@ -1323,6 +1327,7 @@
{
struct htb_sched *q = qdisc_priv(sch);
struct htb_class *cl = (struct htb_class *)arg;
+ unsigned int qlen;
// TODO: why don't allow to delete subtree ? references ? does
// tc subsys quarantee us that in htb_destroy it holds no class
@@ -1336,8 +1341,9 @@
hlist_del_init(&cl->hlist);
if (!cl->level) {
- sch->q.qlen -= cl->un.leaf.q->q.qlen;
+ qlen = cl->un.leaf.q->q.qlen;
qdisc_reset(cl->un.leaf.q);
+ qdisc_tree_decrease_qlen(cl->un.leaf.q, qlen);
}
if (cl->prio_activity)
@@ -1419,8 +1425,11 @@
new_q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, classid);
sch_tree_lock(sch);
if (parent && !parent->level) {
+ unsigned int qlen = parent->un.leaf.q->q.qlen;
+
/* turn parent into inner node */
- sch->q.qlen -= parent->un.leaf.q->q.qlen;
+ qdisc_reset(parent->un.leaf.q);
+ qdisc_tree_decrease_qlen(parent->un.leaf.q, qlen);
qdisc_destroy(parent->un.leaf.q);
if (parent->prio_activity)
htb_deactivate(q, parent);
@@ -1568,6 +1577,7 @@
static struct Qdisc_class_ops htb_class_ops = {
.graft = htb_graft,
.leaf = htb_leaf,
+ .qlen_notify = htb_qlen_notify,
.get = htb_get,
.put = htb_put,
.change = htb_change_class,