2 files changed, 61 insertions, 0 deletions

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 95b560f0b253..b855352167b1 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1173,6 +1173,45 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
 }
 
 /*
+ * enable/disable flow on qdisc.
+ */
+int
+tc_qdisc_flow_control(struct net_device *dev, u32 tcm_handle, int enable_flow)
+{
+	struct Qdisc *q;
+	int qdisc_len = 0;
+	struct __qdisc_change_req {
+		struct nlattr attr;
+		struct tc_prio_qopt data;
+	} req =	{
+		.attr = {sizeof(struct __qdisc_change_req), TCA_OPTIONS},
+		.data = {3, {1, 2, 2, 2, 1, 2, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1}, 1}
+		};
+
+	/* override flow bit */
+	req.data.enable_flow = enable_flow;
+
+	/* look up using tcm handle */
+	q = qdisc_lookup(dev, tcm_handle);
+
+	/* call registered change function */
+	if (likely(q && q->ops)) {
+		if (likely(q->ops->change)) {
+			qdisc_len = q->q.qlen;
+			if (q->ops->change(q, &req.attr) != 0)
+				pr_err("%s(): qdisc change failed", __func__);
+		} else {
+			WARN_ONCE(1, "%s(): called on queue which does %s",
+				  __func__, "not support change() operation");
+		}
+	} else {
+		WARN_ONCE(1, "%s(): called on bad queue", __func__);
+	}
+	return qdisc_len;
+}
+EXPORT_SYMBOL(tc_qdisc_flow_control);
+
+/*
  * Create/change qdisc.
  */
 
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index fee1b15506b2..0d4630b155fe 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -18,6 +18,7 @@
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/skbuff.h>
+#include <linux/netdevice.h>
 #include <net/netlink.h>
 #include <net/pkt_sched.h>
 
@@ -27,6 +28,7 @@ struct prio_sched_data {
 	struct tcf_proto __rcu *filter_list;
 	u8  prio2band[TC_PRIO_MAX+1];
 	struct Qdisc *queues[TCQ_PRIO_BANDS];
+	u8 enable_flow;
 };
 
 
@@ -98,6 +100,9 @@ static struct sk_buff *prio_peek(struct Qdisc *sch)
 	struct prio_sched_data *q = qdisc_priv(sch);
 	int prio;
 
+	if (!q->enable_flow)
+		return NULL;
+
 	for (prio = 0; prio < q->bands; prio++) {
 		struct Qdisc *qdisc = q->queues[prio];
 		struct sk_buff *skb = qdisc->ops->peek(qdisc);
@@ -112,6 +117,9 @@ static struct sk_buff *prio_dequeue(struct Qdisc *sch)
 	struct prio_sched_data *q = qdisc_priv(sch);
 	int prio;
 
+	if (!q->enable_flow)
+		return NULL;
+
 	for (prio = 0; prio < q->bands; prio++) {
 		struct Qdisc *qdisc = q->queues[prio];
 		struct sk_buff *skb = qdisc_dequeue_peeked(qdisc);
@@ -152,6 +160,7 @@ prio_reset(struct Qdisc *sch)
 	for (prio = 0; prio < q->bands; prio++)
 		qdisc_reset(q->queues[prio]);
 	sch->q.qlen = 0;
+	q->enable_flow = 1;
 }
 
 static void
@@ -170,6 +179,7 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
 	struct prio_sched_data *q = qdisc_priv(sch);
 	struct tc_prio_qopt *qopt;
 	int i;
+	int flow_change = 0;
 
 	if (nla_len(opt) < sizeof(*qopt))
 		return -EINVAL;
@@ -184,6 +194,10 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
 	}
 
 	sch_tree_lock(sch);
+	if (q->enable_flow != qopt->enable_flow) {
+		q->enable_flow = qopt->enable_flow;
+		flow_change = 1;
+	}
 	q->bands = qopt->bands;
 	memcpy(q->prio2band, qopt->priomap, TC_PRIO_MAX+1);
 
@@ -219,6 +233,13 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt)
 			}
 		}
 	}
+
+	/* Schedule qdisc when flow re-enabled */
+	if (flow_change && q->enable_flow) {
+		if (!test_bit(__QDISC_STATE_DEACTIVATED,
+			      &sch->state))
+			__netif_schedule(qdisc_root(sch));
+	}
 	return 0;
 }
 
@@ -248,6 +269,7 @@ static int prio_dump(struct Qdisc *sch, struct sk_buff *skb)
 	struct tc_prio_qopt opt;
 
 	opt.bands = q->bands;
+	opt.enable_flow = q->enable_flow;
 	memcpy(&opt.priomap, q->prio2band, TC_PRIO_MAX + 1);
 
 	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))