pkt_sched: Fix locking of qdisc_root with qdisc_root_sleeping_lock()

Use qdisc_root_sleeping_lock() instead of qdisc_root_lock() where
appropriate. The only difference is while dev is deactivated, when
currently we can use a sleeping qdisc with the lock of noop_qdisc.
This shouldn't be dangerous since after deactivation root lock could
be used only by gen_estimator code, but looks wrong anyway.

Signed-off-by: Jarek Poplawski <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/sched/cls_api.c

···
 		}
 	}
 
-	root_lock = qdisc_root_lock(q);
+	root_lock = qdisc_root_sleeping_lock(q);
 
 	if (tp == NULL) {
 		/* Proto-tcf does not exist, create new one */

net/sched/cls_route.c

···
 static inline
 void route4_reset_fastmap(struct Qdisc *q, struct route4_head *head, u32 id)
 {
-	spinlock_t *root_lock = qdisc_root_lock(q);
+	spinlock_t *root_lock = qdisc_root_sleeping_lock(q);
 
 	spin_lock_bh(root_lock);
 	memset(head->fastmap, 0, sizeof(head->fastmap));

net/sched/sch_api.c

···
 	if (q->stab && qdisc_dump_stab(skb, q->stab) < 0)
 		goto nla_put_failure;
 
-	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS,
-					 TCA_XSTATS, qdisc_root_lock(q), &d) < 0)
+	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
+					 qdisc_root_sleeping_lock(q), &d) < 0)
 		goto nla_put_failure;
 
 	if (q->ops->dump_stats && q->ops->dump_stats(q, &d) < 0)
···
 	if (cl_ops->dump && cl_ops->dump(q, cl, skb, tcm) < 0)
 		goto nla_put_failure;
 
-	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS,
-					 TCA_XSTATS, qdisc_root_lock(q), &d) < 0)
+	if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS, TCA_XSTATS,
+					 qdisc_root_sleeping_lock(q), &d) < 0)
 		goto nla_put_failure;
 
 	if (cl_ops->dump_stats && cl_ops->dump_stats(q, cl, &d) < 0)

net/sched/sch_cbq.c

···
 
 	if (--cl->refcnt == 0) {
 #ifdef CONFIG_NET_CLS_ACT
-		spinlock_t *root_lock = qdisc_root_lock(sch);
+		spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
 		struct cbq_sched_data *q = qdisc_priv(sch);
 
 		spin_lock_bh(root_lock);

net/sched/sch_htb.c

···
 
 static int htb_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
-	spinlock_t *root_lock = qdisc_root_lock(sch);
+	spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
 	struct htb_sched *q = qdisc_priv(sch);
 	struct nlattr *nest;
 	struct tc_htb_glob gopt;
···
 			  struct sk_buff *skb, struct tcmsg *tcm)
 {
 	struct htb_class *cl = (struct htb_class *)arg;
-	spinlock_t *root_lock = qdisc_root_lock(sch);
+	spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
 	struct nlattr *nest;
 	struct tc_htb_opt opt;
 

net/sched/sch_netem.c

···
 	for (i = 0; i < n; i++)
 		d->table[i] = data[i];
 
-	root_lock = qdisc_root_lock(sch);
+	root_lock = qdisc_root_sleeping_lock(sch);
 
 	spin_lock_bh(root_lock);
 	d = xchg(&q->delay_dist, d);

net/sched/sch_teql.c

···
 						txq = netdev_get_tx_queue(master->dev, 0);
 						master->slaves = NULL;
 
-						root_lock = qdisc_root_lock(txq->qdisc);
+						root_lock = qdisc_root_sleeping_lock(txq->qdisc);
 						spin_lock_bh(root_lock);
 						qdisc_reset(txq->qdisc);
 						spin_unlock_bh(root_lock);