net_sched: remove some unnecessary checks in classful schedulers

The class argument to the ->graft(), ->leaf(), ->dump(), ->dump_stats() all
originate from either ->get() or ->walk() and are always valid.

Remove unnecessary checks.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_cbq.c

@@ -1621,11 +1621,9 @@ static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 {
 	struct cbq_class *cl = (struct cbq_class*)arg;
 
-	if (cl) {
 	if (new == NULL) {
 		new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
-						&pfifo_qdisc_ops,
-						cl->common.classid);
+					&pfifo_qdisc_ops, cl->common.classid);
 		if (new == NULL)
 			return -ENOBUFS;
 	} else {
@@ -1642,8 +1640,6 @@ static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 	sch_tree_unlock(sch);
 
 	return 0;
-	}
-	return -ENOENT;
 }
 
 static struct Qdisc *
@@ -1651,7 +1647,7 @@ cbq_leaf(struct Qdisc *sch, unsigned long arg)
 {
 	struct cbq_class *cl = (struct cbq_class*)arg;
 
-	return cl ? cl->q : NULL;
+	return cl->q;
 }
 
 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)

net/sched/sch_hfsc.c

@@ -1203,8 +1203,6 @@ hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 {
 	struct hfsc_class *cl = (struct hfsc_class *)arg;
 
-	if (cl == NULL)
-		return -ENOENT;
 	if (cl->level > 0)
 		return -EINVAL;
 	if (new == NULL) {
@@ -1228,7 +1226,7 @@ hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
 {
 	struct hfsc_class *cl = (struct hfsc_class *)arg;
 
-	if (cl != NULL && cl->level == 0)
+	if (cl->level == 0)
 		return cl->qdisc;
 
 	return NULL;

net/sched/sch_htb.c

@@ -1117,13 +1117,14 @@ static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 {
 	struct htb_class *cl = (struct htb_class *)arg;
 
-	if (cl && !cl->level) {
+	if (cl->level)
+		return -EINVAL;
 	if (new == NULL &&
 	    (new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
 				     &pfifo_qdisc_ops,
-					     cl->common.classid))
-		    == NULL)
+				     cl->common.classid)) == NULL)
 		return -ENOBUFS;
+
 	sch_tree_lock(sch);
 	*old = cl->un.leaf.q;
 	cl->un.leaf.q = new;
@@ -1133,14 +1134,12 @@ static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 	}
 	sch_tree_unlock(sch);
 	return 0;
-	}
-	return -ENOENT;
 }
 
 static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg)
 {
 	struct htb_class *cl = (struct htb_class *)arg;
-	return (cl && !cl->level) ? cl->un.leaf.q : NULL;
+	return !cl->level ? cl->un.leaf.q : NULL;
 }
 
 static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg)

net/sched/sch_multiq.c

@@ -298,9 +298,6 @@ static int multiq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 	struct multiq_sched_data *q = qdisc_priv(sch);
 	unsigned long band = arg - 1;
 
-	if (band >= q->bands)
-		return -EINVAL;
-
 	if (new == NULL)
 		new = &noop_qdisc;
 
@@ -320,9 +317,6 @@ multiq_leaf(struct Qdisc *sch, unsigned long arg)
 	struct multiq_sched_data *q = qdisc_priv(sch);
 	unsigned long band = arg - 1;
 
-	if (band >= q->bands)
-		return NULL;
-
 	return q->queues[band];
 }
 
@@ -353,10 +347,7 @@ static int multiq_dump_class(struct Qdisc *sch, unsigned long cl,
 {
 	struct multiq_sched_data *q = qdisc_priv(sch);
 
-	if (cl - 1 > q->bands)
-		return -ENOENT;
 	tcm->tcm_handle |= TC_H_MIN(cl);
-	if (q->queues[cl-1])
 	tcm->tcm_info = q->queues[cl-1]->handle;
 	return 0;
 }

net/sched/sch_prio.c

@@ -262,9 +262,6 @@ static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
 	struct prio_sched_data *q = qdisc_priv(sch);
 	unsigned long band = arg - 1;
 
-	if (band >= q->bands)
-		return -EINVAL;
-
 	if (new == NULL)
 		new = &noop_qdisc;
 
@@ -284,9 +281,6 @@ prio_leaf(struct Qdisc *sch, unsigned long arg)
 	struct prio_sched_data *q = qdisc_priv(sch);
 	unsigned long band = arg - 1;
 
-	if (band >= q->bands)
-		return NULL;
-
 	return q->queues[band];
 }
 
@@ -316,10 +310,7 @@ static int prio_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *
 {
 	struct prio_sched_data *q = qdisc_priv(sch);
 
-	if (cl - 1 > q->bands)
-		return -ENOENT;
 	tcm->tcm_handle |= TC_H_MIN(cl);
-	if (q->queues[cl-1])
 	tcm->tcm_info = q->queues[cl-1]->handle;
 	return 0;
 }

net/sched/sch_red.c

@@ -268,8 +268,6 @@ static int red_dump_class(struct Qdisc *sch, unsigned long cl,
 {
 	struct red_sched_data *q = qdisc_priv(sch);
 
-	if (cl != 1)
-		return -ENOENT;
 	tcm->tcm_handle |= TC_H_MIN(1);
 	tcm->tcm_info = q->qdisc->handle;
 	return 0;

net/sched/sch_tbf.c

@@ -368,9 +368,6 @@ static int tbf_dump_class(struct Qdisc *sch, unsigned long cl,
 {
 	struct tbf_sched_data *q = qdisc_priv(sch);
 
-	if (cl != 1) 	/* only one class */
-		return -ENOENT;
-
 	tcm->tcm_handle |= TC_H_MIN(1);
 	tcm->tcm_info = q->qdisc->handle;