[NET_SCHED] sch_cbq: deactivating when grafting, purging etc.

- deactivating of active classes when q.qlen drops to zero
  (cbq_drop)

- a redundant instruction removed from cbq_deactivate_class

PS: probably htb_deactivate in htb_delete and
cbq_deactivate_class in cbq_delete are also
redundant now.

Signed-off-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 4 deletions

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index ba82dfab6043..f79a4f3d0a95 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -371,8 +371,6 @@ static void cbq_deactivate_class(struct cbq_class *this)
                                         return;
                                 }
                         }
-
-                        cl = cl_prev->next_alive;
                         return;
                 }
         } while ((cl_prev = cl) != q->active[prio]);
@@ -1258,6 +1256,8 @@ static unsigned int cbq_drop(struct Qdisc* sch)
                 do {
                         if (cl->q->ops->drop && (len = cl->q->ops->drop(cl->q))) {
                                 sch->q.qlen--;
+                                if (!cl->q->q.qlen)
+                                        cbq_deactivate_class(cl);
                                 return len;
                         }
                 } while ((cl = cl->next_alive) != cl_head);
@@ -1685,8 +1685,7 @@ static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 #endif
                 }
                 sch_tree_lock(sch);
-                *old = cl->q;
-                cl->q = new;
+                *old = xchg(&cl->q, new);
                 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
                 qdisc_reset(*old);
                 sch_tree_unlock(sch);
@@ -1704,6 +1703,14 @@ cbq_leaf(struct Qdisc *sch, unsigned long arg)
         return cl ? cl->q : NULL;
 }
 
+static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
+{
+        struct cbq_class *cl = (struct cbq_class *)arg;
+
+        if (cl->q->q.qlen == 0)
+                cbq_deactivate_class(cl);
+}
+
 static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
 {
         struct cbq_sched_data *q = qdisc_priv(sch);
@@ -1988,12 +1995,17 @@ static int cbq_delete(struct Qdisc *sch, unsigned long arg)
 {
         struct cbq_sched_data *q = qdisc_priv(sch);
         struct cbq_class *cl = (struct cbq_class*)arg;
+        unsigned int qlen;
 
         if (cl->filters || cl->children || cl == &q->link)
                 return -EBUSY;
 
         sch_tree_lock(sch);
 
+        qlen = cl->q->q.qlen;
+        qdisc_reset(cl->q);
+        qdisc_tree_decrease_qlen(cl->q, qlen);
+
         if (cl->next_alive)
                 cbq_deactivate_class(cl);
 
@@ -2084,6 +2096,7 @@ static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 static struct Qdisc_class_ops cbq_class_ops = {
         .graft          =       cbq_graft,
         .leaf           =       cbq_leaf,
+        .qlen_notify    =       cbq_qlen_notify,
         .get            =       cbq_get,
         .put            =       cbq_put,
         .change         =       cbq_change_class,