1 files changed, 23 insertions, 8 deletions

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 11c03cf4aa74..17bd8f539bc7 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -46,6 +46,8 @@ EXPORT_SYMBOL(default_qdisc_ops);
  * - updates to tree and tree walking are only done under the rtnl mutex.
  */
 
+#define SKB_XOFF_MAGIC ((struct sk_buff *)1UL)
+
 static inline struct sk_buff *__skb_dequeue_bad_txq(struct Qdisc *q)
 {
 	const struct netdev_queue *txq = q->dev_queue;
@@ -71,7 +73,7 @@ static inline struct sk_buff *__skb_dequeue_bad_txq(struct Qdisc *q)
 				q->q.qlen--;
 			}
 		} else {
-			skb = NULL;
+			skb = SKB_XOFF_MAGIC;
 		}
 	}
 
@@ -253,8 +255,11 @@ validate:
 		return skb;
 
 	skb = qdisc_dequeue_skb_bad_txq(q);
-	if (unlikely(skb))
+	if (unlikely(skb)) {
+		if (skb == SKB_XOFF_MAGIC)
+			return NULL;
 		goto bulk;
+	}
 	skb = q->dequeue(q);
 	if (skb) {
 bulk:
@@ -624,8 +629,12 @@ static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
 
 	err = skb_array_produce(q, skb);
 
-	if (unlikely(err))
-		return qdisc_drop_cpu(skb, qdisc, to_free);
+	if (unlikely(err)) {
+		if (qdisc_is_percpu_stats(qdisc))
+			return qdisc_drop_cpu(skb, qdisc, to_free);
+		else
+			return qdisc_drop(skb, qdisc, to_free);
+	}
 
 	qdisc_update_stats_at_enqueue(qdisc, pkt_len);
 	return NET_XMIT_SUCCESS;
@@ -688,11 +697,14 @@ static void pfifo_fast_reset(struct Qdisc *qdisc)
 			kfree_skb(skb);
 	}
 
-	for_each_possible_cpu(i) {
-		struct gnet_stats_queue *q = per_cpu_ptr(qdisc->cpu_qstats, i);
+	if (qdisc_is_percpu_stats(qdisc)) {
+		for_each_possible_cpu(i) {
+			struct gnet_stats_queue *q;
 
-		q->backlog = 0;
-		q->qlen = 0;
+			q = per_cpu_ptr(qdisc->cpu_qstats, i);
+			q->backlog = 0;
+			q->qlen = 0;
+		}
 	}
 }
 
@@ -973,6 +985,9 @@ static void qdisc_destroy(struct Qdisc *qdisc)
 
 void qdisc_put(struct Qdisc *qdisc)
 {
+	if (!qdisc)
+		return;
+
 	if (qdisc->flags & TCQ_F_BUILTIN ||
 	    !refcount_dec_and_test(&qdisc->refcnt))
 		return;