net: sched: rename qdisc_destroy() to qdisc_put()

Current implementation of qdisc_destroy() decrements Qdisc reference
counter and only actually destroy Qdisc if reference counter value reached
zero. Rename qdisc_destroy() to qdisc_put() in order for it to better
describe the way in which this function currently implemented and used.

Extract code that deallocates Qdisc into new private qdisc_destroy()
function. It is intended to be shared between regular qdisc_put() and its
unlocked version that is introduced in next patch in this series.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

20 files changed, 47 insertions, 42 deletions

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index d326fd553b58..fadb1a4d4ee8 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -554,7 +554,7 @@ void dev_deactivate_many(struct list_head *head);
 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
                               struct Qdisc *qdisc);
 void qdisc_reset(struct Qdisc *qdisc);
-void qdisc_destroy(struct Qdisc *qdisc);
+void qdisc_put(struct Qdisc *qdisc);
 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
                                unsigned int len);
 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 411c40344b77..2096138c4bf6 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -920,7 +920,7 @@ static void notify_and_destroy(struct net *net, struct sk_buff *skb,
                 qdisc_notify(net, skb, n, clid, old, new);
 
         if (old)
-                qdisc_destroy(old);
+                qdisc_put(old);
 }
 
 /* Graft qdisc "new" to class "classid" of qdisc "parent" or
@@ -973,7 +973,7 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
                                 qdisc_refcount_inc(new);
 
                         if (!ingress)
-                                qdisc_destroy(old);
+                                qdisc_put(old);
                 }
 
 skip:
@@ -1561,7 +1561,7 @@ graft:
         err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
         if (err) {
                 if (q)
-                        qdisc_destroy(q);
+                        qdisc_put(q);
                 return err;
         }
 
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index cd49afca9617..d714d3747bcb 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -150,7 +150,7 @@ static void atm_tc_put(struct Qdisc *sch, unsigned long cl)
         pr_debug("atm_tc_put: destroying\n");
         list_del_init(&flow->list);
         pr_debug("atm_tc_put: qdisc %p\n", flow->q);
-        qdisc_destroy(flow->q);
+        qdisc_put(flow->q);
         tcf_block_put(flow->block);
         if (flow->sock) {
                 pr_debug("atm_tc_put: f_count %ld\n",
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index f42025d53cfe..4dc05409e3fb 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1418,7 +1418,7 @@ static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
         WARN_ON(cl->filters);
 
         tcf_block_put(cl->block);
-        qdisc_destroy(cl->q);
+        qdisc_put(cl->q);
         qdisc_put_rtab(cl->R_tab);
         gen_kill_estimator(&cl->rate_est);
         if (cl != &q->link)
diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c
index e26a24017faa..e689e11b6d0f 100644
--- a/net/sched/sch_cbs.c
+++ b/net/sched/sch_cbs.c
@@ -379,7 +379,7 @@ static void cbs_destroy(struct Qdisc *sch)
         cbs_disable_offload(dev, q);
 
         if (q->qdisc)
-                qdisc_destroy(q->qdisc);
+                qdisc_put(q->qdisc);
 }
 
 static int cbs_dump(struct Qdisc *sch, struct sk_buff *skb)
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index e0b0cf8a9939..cdebaed0f8cf 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -134,7 +134,7 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
                                             tca[TCA_RATE]);
                 if (err) {
                         NL_SET_ERR_MSG(extack, "Failed to replace estimator");
-                        qdisc_destroy(cl->qdisc);
+                        qdisc_put(cl->qdisc);
                         kfree(cl);
                         return err;
                 }
@@ -153,7 +153,7 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
 {
         gen_kill_estimator(&cl->rate_est);
-        qdisc_destroy(cl->qdisc);
+        qdisc_put(cl->qdisc);
         kfree(cl);
 }
 
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index 049714c57075..f6f480784bc6 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -412,7 +412,7 @@ static void dsmark_destroy(struct Qdisc *sch)
         pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
 
         tcf_block_put(p->block);
-        qdisc_destroy(p->q);
+        qdisc_put(p->q);
         if (p->mv != p->embedded)
                 kfree(p->mv);
 }
diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
index 24893d3b5d22..3809c9bf8896 100644
--- a/net/sched/sch_fifo.c
+++ b/net/sched/sch_fifo.c
@@ -177,7 +177,7 @@ struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
         if (q) {
                 err = fifo_set_limit(q, limit);
                 if (err < 0) {
-                        qdisc_destroy(q);
+                        qdisc_put(q);
                         q = NULL;
                 }
         }
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index a64132a5db36..3e7696f3e053 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -901,7 +901,7 @@ struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
         if (!ops->init || ops->init(sch, NULL, extack) == 0)
                 return sch;
 
-        qdisc_destroy(sch);
+        qdisc_put(sch);
         return NULL;
 }
 EXPORT_SYMBOL(qdisc_create_dflt);
@@ -941,15 +941,11 @@ void qdisc_free(struct Qdisc *qdisc)
         kfree((char *) qdisc - qdisc->padded);
 }
 
-void qdisc_destroy(struct Qdisc *qdisc)
+static void qdisc_destroy(struct Qdisc *qdisc)
 {
         const struct Qdisc_ops  *ops = qdisc->ops;
         struct sk_buff *skb, *tmp;
 
-        if (qdisc->flags & TCQ_F_BUILTIN ||
-            !refcount_dec_and_test(&qdisc->refcnt))
-                return;
-
 #ifdef CONFIG_NET_SCHED
         qdisc_hash_del(qdisc);
 
@@ -976,7 +972,16 @@ void qdisc_destroy(struct Qdisc *qdisc)
 
         qdisc_free(qdisc);
 }
-EXPORT_SYMBOL(qdisc_destroy);
+
+void qdisc_put(struct Qdisc *qdisc)
+{
+        if (qdisc->flags & TCQ_F_BUILTIN ||
+            !refcount_dec_and_test(&qdisc->refcnt))
+                return;
+
+        qdisc_destroy(qdisc);
+}
+EXPORT_SYMBOL(qdisc_put);
 
 /* Attach toplevel qdisc to device queue. */
 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
@@ -1270,7 +1275,7 @@ static void shutdown_scheduler_queue(struct net_device *dev,
                 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
                 dev_queue->qdisc_sleeping = qdisc_default;
 
-                qdisc_destroy(qdisc);
+                qdisc_put(qdisc);
         }
 }
 
@@ -1279,7 +1284,7 @@ void dev_shutdown(struct net_device *dev)
         netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
         if (dev_ingress_queue(dev))
                 shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
-        qdisc_destroy(dev->qdisc);
+        qdisc_put(dev->qdisc);
         dev->qdisc = &noop_qdisc;
 
         WARN_ON(timer_pending(&dev->watchdog_timer));
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 3278a76f6861..b18ec1f6de60 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1092,7 +1092,7 @@ hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
         struct hfsc_sched *q = qdisc_priv(sch);
 
         tcf_block_put(cl->block);
-        qdisc_destroy(cl->qdisc);
+        qdisc_put(cl->qdisc);
         gen_kill_estimator(&cl->rate_est);
         if (cl != &q->root)
                 kfree(cl);
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 18ac2d6ca294..58b449490757 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1208,7 +1208,7 @@ static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
 {
         if (!cl->level) {
                 WARN_ON(!cl->leaf.q);
-                qdisc_destroy(cl->leaf.q);
+                qdisc_put(cl->leaf.q);
         }
         gen_kill_estimator(&cl->rate_est);
         tcf_block_put(cl->block);
@@ -1409,7 +1409,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
                         /* turn parent into inner node */
                         qdisc_reset(parent->leaf.q);
                         qdisc_tree_reduce_backlog(parent->leaf.q, qlen, backlog);
-                        qdisc_destroy(parent->leaf.q);
+                        qdisc_put(parent->leaf.q);
                         if (parent->prio_activity)
                                 htb_deactivate(q, parent);
 
diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index d6b8ae4ed7a3..f20f3a0f8424 100644
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -65,7 +65,7 @@ static void mq_destroy(struct Qdisc *sch)
         if (!priv->qdiscs)
                 return;
         for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++)
-                qdisc_destroy(priv->qdiscs[ntx]);
+                qdisc_put(priv->qdiscs[ntx]);
         kfree(priv->qdiscs);
 }
 
@@ -119,7 +119,7 @@ static void mq_attach(struct Qdisc *sch)
                 qdisc = priv->qdiscs[ntx];
                 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
                 if (old)
-                        qdisc_destroy(old);
+                        qdisc_put(old);
 #ifdef CONFIG_NET_SCHED
                 if (ntx < dev->real_num_tx_queues)
                         qdisc_hash_add(qdisc, false);
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 0e9d761cdd80..d364e63c396d 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -40,7 +40,7 @@ static void mqprio_destroy(struct Qdisc *sch)
                 for (ntx = 0;
                      ntx < dev->num_tx_queues && priv->qdiscs[ntx];
                      ntx++)
-                        qdisc_destroy(priv->qdiscs[ntx]);
+                        qdisc_put(priv->qdiscs[ntx]);
                 kfree(priv->qdiscs);
         }
 
@@ -300,7 +300,7 @@ static void mqprio_attach(struct Qdisc *sch)
                 qdisc = priv->qdiscs[ntx];
                 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
                 if (old)
-                        qdisc_destroy(old);
+                        qdisc_put(old);
                 if (ntx < dev->real_num_tx_queues)
                         qdisc_hash_add(qdisc, false);
         }
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 1da7ea8de0ad..7410ce4d0321 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -175,7 +175,7 @@ multiq_destroy(struct Qdisc *sch)
 
         tcf_block_put(q->block);
         for (band = 0; band < q->bands; band++)
-                qdisc_destroy(q->queues[band]);
+                qdisc_put(q->queues[band]);
 
         kfree(q->queues);
 }
@@ -204,7 +204,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt,
                         q->queues[i] = &noop_qdisc;
                         qdisc_tree_reduce_backlog(child, child->q.qlen,
                                                   child->qstats.backlog);
-                        qdisc_destroy(child);
+                        qdisc_put(child);
                 }
         }
 
@@ -228,7 +228,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt,
                                         qdisc_tree_reduce_backlog(old,
                                                                   old->q.qlen,
                                                                   old->qstats.backlog);
-                                        qdisc_destroy(old);
+                                        qdisc_put(old);
                                 }
                                 sch_tree_unlock(sch);
                         }
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 506e1960ed7f..57b3ad9394ad 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -1022,7 +1022,7 @@ static void netem_destroy(struct Qdisc *sch)
 
         qdisc_watchdog_cancel(&q->watchdog);
         if (q->qdisc)
-                qdisc_destroy(q->qdisc);
+                qdisc_put(q->qdisc);
         dist_free(q->delay_dist);
         dist_free(q->slot_dist);
 }
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 222e53d3d27a..f8af98621179 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -175,7 +175,7 @@ prio_destroy(struct Qdisc *sch)
         tcf_block_put(q->block);
         prio_offload(sch, NULL);
         for (prio = 0; prio < q->bands; prio++)
-                qdisc_destroy(q->queues[prio]);
+                qdisc_put(q->queues[prio]);
 }
 
 static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
@@ -205,7 +205,7 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
                                               extack);
                 if (!queues[i]) {
                         while (i > oldbands)
-                                qdisc_destroy(queues[--i]);
+                                qdisc_put(queues[--i]);
                         return -ENOMEM;
                 }
         }
@@ -220,7 +220,7 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
 
                 qdisc_tree_reduce_backlog(child, child->q.qlen,
                                           child->qstats.backlog);
-                qdisc_destroy(child);
+                qdisc_put(child);
         }
 
         for (i = oldbands; i < q->bands; i++) {
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index bb1a9c11fc54..dc37c4ead439 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -526,7 +526,7 @@ set_change_agg:
         return 0;
 
 destroy_class:
-        qdisc_destroy(cl->qdisc);
+        qdisc_put(cl->qdisc);
         kfree(cl);
         return err;
 }
@@ -537,7 +537,7 @@ static void qfq_destroy_class(struct Qdisc *sch, struct qfq_class *cl)
 
         qfq_rm_from_agg(q, cl);
         gen_kill_estimator(&cl->rate_est);
-        qdisc_destroy(cl->qdisc);
+        qdisc_put(cl->qdisc);
         kfree(cl);
 }
 
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 56c181c3feeb..3ce6c0a2c493 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -181,7 +181,7 @@ static void red_destroy(struct Qdisc *sch)
 
         del_timer_sync(&q->adapt_timer);
         red_offload(sch, false);
-        qdisc_destroy(q->qdisc);
+        qdisc_put(q->qdisc);
 }
 
 static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
@@ -233,7 +233,7 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
         if (child) {
                 qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
                                           q->qdisc->qstats.backlog);
-                qdisc_destroy(q->qdisc);
+                qdisc_put(q->qdisc);
                 q->qdisc = child;
         }
 
diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index 7cbdad8419b7..bab506b01a32 100644
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c
@@ -469,7 +469,7 @@ static void sfb_destroy(struct Qdisc *sch)
         struct sfb_sched_data *q = qdisc_priv(sch);
 
         tcf_block_put(q->block);
-        qdisc_destroy(q->qdisc);
+        qdisc_put(q->qdisc);
 }
 
 static const struct nla_policy sfb_policy[TCA_SFB_MAX + 1] = {
@@ -523,7 +523,7 @@ static int sfb_change(struct Qdisc *sch, struct nlattr *opt,
 
         qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
                                   q->qdisc->qstats.backlog);
-        qdisc_destroy(q->qdisc);
+        qdisc_put(q->qdisc);
         q->qdisc = child;
 
         q->rehash_interval = msecs_to_jiffies(ctl->rehash_interval);
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index a4530e85bd02..942dcca09cf2 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -392,7 +392,7 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt,
         if (child) {
                 qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
                                           q->qdisc->qstats.backlog);
-                qdisc_destroy(q->qdisc);
+                qdisc_put(q->qdisc);
                 q->qdisc = child;
         }
         q->limit = qopt->limit;
@@ -438,7 +438,7 @@ static void tbf_destroy(struct Qdisc *sch)
         struct tbf_sched_data *q = qdisc_priv(sch);
 
         qdisc_watchdog_cancel(&q->watchdog);
-        qdisc_destroy(q->qdisc);
+        qdisc_put(q->qdisc);
 }
 
 static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)