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>

7 files changed, 37 insertions, 67 deletions

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index d5798e17a832..5b132c473264 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1621,29 +1621,25 @@ 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);
-                        if (new == NULL)
-                                return -ENOBUFS;
-                } else {
+        if (new == NULL) {
+                new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
+                                        &pfifo_qdisc_ops, cl->common.classid);
+                if (new == NULL)
+                        return -ENOBUFS;
+        } else {
 #ifdef CONFIG_NET_CLS_ACT
-                        if (cl->police == TC_POLICE_RECLASSIFY)
-                                new->reshape_fail = cbq_reshape_fail;
+                if (cl->police == TC_POLICE_RECLASSIFY)
+                        new->reshape_fail = cbq_reshape_fail;
 #endif
-                }
-                sch_tree_lock(sch);
-                *old = cl->q;
-                cl->q = new;
-                qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
-                qdisc_reset(*old);
-                sch_tree_unlock(sch);
-
-                return 0;
         }
-        return -ENOENT;
+        sch_tree_lock(sch);
+        *old = cl->q;
+        cl->q = new;
+        qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
+        qdisc_reset(*old);
+        sch_tree_unlock(sch);
+
+        return 0;
 }
 
 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)
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index dad0144423da..375d64cb1a3d 100644
--- a/net/sched/sch_hfsc.c
+++ b/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;
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index ec4d46399d59..85acab9dc6fd 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1117,30 +1117,29 @@ 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 (new == NULL &&
-                    (new = qdisc_create_dflt(qdisc_dev(sch), sch->dev_queue,
-                                             &pfifo_qdisc_ops,
-                                             cl->common.classid))
-                    == NULL)
-                        return -ENOBUFS;
-                sch_tree_lock(sch);
-                *old = cl->un.leaf.q;
-                cl->un.leaf.q = new;
-                if (*old != NULL) {
-                        qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
-                        qdisc_reset(*old);
-                }
-                sch_tree_unlock(sch);
-                return 0;
+        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)
+                return -ENOBUFS;
+
+        sch_tree_lock(sch);
+        *old = cl->un.leaf.q;
+        cl->un.leaf.q = new;
+        if (*old != NULL) {
+                qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
+                qdisc_reset(*old);
         }
-        return -ENOENT;
+        sch_tree_unlock(sch);
+        return 0;
 }
 
 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)
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index a0ffe7158ff3..069f81c97277 100644
--- a/net/sched/sch_multiq.c
+++ b/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];
 }
 
@@ -353,11 +347,8 @@ 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;
+        tcm->tcm_info = q->queues[cl-1]->handle;
         return 0;
 }
 
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 209a4ca4b98d..0f73c412d04b 100644
--- a/net/sched/sch_prio.c
+++ b/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];
 }
 
@@ -316,11 +310,8 @@ 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;
+        tcm->tcm_info = q->queues[cl-1]->handle;
         return 0;
 }
 
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index a2c4d1aa3cb1..072cdf442f8e 100644
--- a/net/sched/sch_red.c
+++ b/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;
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index d904167e73b3..8fb8107ab188 100644
--- a/net/sched/sch_tbf.c
+++ b/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;