net_sched: remove tc class reference counting

For TC classes, their ->get() and ->put() are always paired, and the
reference counting is completely useless, because:

1) For class modification and dumping paths, we already hold RTNL lock,
   so all of these ->get(),->change(),->put() are atomic.

2) For filter bindiing/unbinding, we use other reference counter than
   this one, and they should have RTNL lock too.

3) For ->qlen_notify(), it is special because it is called on ->enqueue()
   path, but we already hold qdisc tree lock there, and we hold this
   tree lock when graft or delete the class too, so it should not be gone
   or changed until we release the tree lock.

Therefore, this patch removes ->get() and ->put(), but:

1) Adds a new ->find() to find the pointer to a class by classid, no
   refcnt.

2) Move the original class destroy upon the last refcnt into ->delete(),
   right after releasing tree lock. This is fine because the class is
   already removed from hash when holding the lock.

For those who also use ->put() as ->unbind(), just rename them to reflect
this change.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sch_generic.h

@@ -147,8 +147,7 @@ struct Qdisc_class_ops {
 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
 
 	/* Class manipulation routines */
-	unsigned long		(*get)(struct Qdisc *, u32 classid);
-	void			(*put)(struct Qdisc *, unsigned long);
+	unsigned long		(*find)(struct Qdisc *, u32 classid);
 	int			(*change)(struct Qdisc *, u32, u32,
 					struct nlattr **, unsigned long *);
 	int			(*delete)(struct Qdisc *, unsigned long);

net/sched/cls_api.c

@@ -586,7 +586,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 
 	/* Do we search for filter, attached to class? */
 	if (TC_H_MIN(parent)) {
-		cl = cops->get(q, parent);
+		cl = cops->find(q, parent);
 		if (cl == 0)
 			return -ENOENT;
 	}
@@ -716,8 +716,6 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
 errout:
 	if (chain)
 		tcf_chain_put(chain);
-	if (cl)
-		cops->put(q, cl);
 	if (err == -EAGAIN)
 		/* Replay the request. */
 		goto replay;
@@ -822,17 +820,17 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 		goto out;
 	cops = q->ops->cl_ops;
 	if (!cops)
-		goto errout;
+		goto out;
 	if (!cops->tcf_block)
-		goto errout;
+		goto out;
 	if (TC_H_MIN(tcm->tcm_parent)) {
-		cl = cops->get(q, tcm->tcm_parent);
+		cl = cops->find(q, tcm->tcm_parent);
 		if (cl == 0)
-			goto errout;
+			goto out;
 	}
 	block = cops->tcf_block(q, cl);
 	if (!block)
-		goto errout;
+		goto out;
 
 	index_start = cb->args[0];
 	index = 0;
@@ -847,9 +845,6 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
 
 	cb->args[0] = index;
 
-errout:
-	if (cl)
-		cops->put(q, cl);
 out:
 	return skb->len;
 }

net/sched/sch_api.c

@@ -153,7 +153,7 @@ int register_qdisc(struct Qdisc_ops *qops)
 	if (qops->cl_ops) {
 		const struct Qdisc_class_ops *cops = qops->cl_ops;
 
-		if (!(cops->get && cops->put && cops->walk && cops->leaf))
+		if (!(cops->find && cops->walk && cops->leaf))
 			goto out_einval;
 
 		if (cops->tcf_block && !(cops->bind_tcf && cops->unbind_tcf))
@@ -320,12 +320,11 @@ static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
 
 	if (cops == NULL)
 		return NULL;
-	cl = cops->get(p, classid);
+	cl = cops->find(p, classid);
 
 	if (cl == 0)
 		return NULL;
 	leaf = cops->leaf(p, cl);
-	cops->put(p, cl);
 	return leaf;
 }
 
@@ -756,9 +755,8 @@ void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
 		}
 		cops = sch->ops->cl_ops;
 		if (notify && cops->qlen_notify) {
-			cl = cops->get(sch, parentid);
+			cl = cops->find(sch, parentid);
 			cops->qlen_notify(sch, cl);
-			cops->put(sch, cl);
 		}
 		sch->q.qlen -= n;
 		sch->qstats.backlog -= len;
@@ -955,11 +953,11 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
 
 		err = -EOPNOTSUPP;
 		if (cops && cops->graft) {
-			unsigned long cl = cops->get(parent, classid);
-			if (cl) {
+			unsigned long cl = cops->find(parent, classid);
+
+			if (cl)
 				err = cops->graft(parent, cl, new, &old);
-				cops->put(parent, cl);
-			} else
+			else
 				err = -ENOENT;
 		}
 		if (!err)
@@ -1739,7 +1737,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
 		clid = TC_H_MAKE(qid, clid);
 
 	if (clid)
-		cl = cops->get(q, clid);
+		cl = cops->find(q, clid);
 
 	if (cl == 0) {
 		err = -ENOENT;
@@ -1773,9 +1771,6 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n,
 		tclass_notify(net, skb, n, q, new_cl, RTM_NEWTCLASS);
 
 out:
-	if (cl)
-		cops->put(q, cl);
-
 	return err;
 }
 

net/sched/sch_atm.c

@@ -108,23 +108,29 @@ static struct Qdisc *atm_tc_leaf(struct Qdisc *sch, unsigned long cl)
 	return flow ? flow->q : NULL;
 }
 
-static unsigned long atm_tc_get(struct Qdisc *sch, u32 classid)
+static unsigned long atm_tc_find(struct Qdisc *sch, u32 classid)
 {
 	struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);
 	struct atm_flow_data *flow;
 
-	pr_debug("atm_tc_get(sch %p,[qdisc %p],classid %x)\n", sch, p, classid);
+	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n", __func__, sch, p, classid);
 	flow = lookup_flow(sch, classid);
-	if (flow)
-		flow->ref++;
-	pr_debug("atm_tc_get: flow %p\n", flow);
+	pr_debug("%s: flow %p\n", __func__, flow);
 	return (unsigned long)flow;
 }
 
 static unsigned long atm_tc_bind_filter(struct Qdisc *sch,
 					unsigned long parent, u32 classid)
 {
-	return atm_tc_get(sch, classid);
+	struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);
+	struct atm_flow_data *flow;
+
+	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n", __func__, sch, p, classid);
+	flow = lookup_flow(sch, classid);
+	if (flow)
+		flow->ref++;
+	pr_debug("%s: flow %p\n", __func__, flow);
+	return (unsigned long)flow;
 }
 
 /*
@@ -234,7 +240,7 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
 		excess = NULL;
 	else {
 		excess = (struct atm_flow_data *)
-			atm_tc_get(sch, nla_get_u32(tb[TCA_ATM_EXCESS]));
+			atm_tc_find(sch, nla_get_u32(tb[TCA_ATM_EXCESS]));
 		if (!excess)
 			return -ENOENT;
 	}
@@ -262,10 +268,9 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
 
 		for (i = 1; i < 0x8000; i++) {
 			classid = TC_H_MAKE(sch->handle, 0x8000 | i);
-			cl = atm_tc_get(sch, classid);
+			cl = atm_tc_find(sch, classid);
 			if (!cl)
 				break;
-			atm_tc_put(sch, cl);
 		}
 	}
 	pr_debug("atm_tc_change: new id %x\n", classid);
@@ -305,8 +310,6 @@ static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
 	*arg = (unsigned long)flow;
 	return 0;
 err_out:
-	if (excess)
-		atm_tc_put(sch, (unsigned long)excess);
 	sockfd_put(sock);
 	return error;
 }
@@ -377,7 +380,7 @@ static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	result = TC_ACT_OK;	/* be nice to gcc */
 	flow = NULL;
 	if (TC_H_MAJ(skb->priority) != sch->handle ||
-	    !(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority))) {
+	    !(flow = (struct atm_flow_data *)atm_tc_find(sch, skb->priority))) {
 		struct tcf_proto *fl;
 
 		list_for_each_entry(flow, &p->flows, list) {
@@ -655,8 +658,7 @@ static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
 static const struct Qdisc_class_ops atm_class_ops = {
 	.graft		= atm_tc_graft,
 	.leaf		= atm_tc_leaf,
-	.get		= atm_tc_get,
-	.put		= atm_tc_put,
+	.find		= atm_tc_find,
 	.change		= atm_tc_change,
 	.delete		= atm_tc_delete,
 	.walk		= atm_tc_walk,

net/sched/sch_cbq.c

@@ -129,7 +129,6 @@ struct cbq_class {
 	struct tcf_proto __rcu	*filter_list;
 	struct tcf_block	*block;
 
-	int			refcnt;
 	int			filters;
 
 	struct cbq_class	*defaults[TC_PRIO_MAX + 1];
@@ -1155,7 +1154,6 @@ static int cbq_init(struct Qdisc *sch, struct nlattr *opt)
 	if (err < 0)
 		goto put_rtab;
 
-	q->link.refcnt = 1;
 	q->link.sibling = &q->link;
 	q->link.common.classid = sch->handle;
 	q->link.qdisc = sch;
@@ -1388,16 +1386,11 @@ static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg)
 	cbq_deactivate_class(cl);
 }
 
-static unsigned long cbq_get(struct Qdisc *sch, u32 classid)
+static unsigned long cbq_find(struct Qdisc *sch, u32 classid)
 {
 	struct cbq_sched_data *q = qdisc_priv(sch);
-	struct cbq_class *cl = cbq_class_lookup(q, classid);
 
-	if (cl) {
-		cl->refcnt++;
-		return (unsigned long)cl;
-	}
-	return 0;
+	return (unsigned long)cbq_class_lookup(q, classid);
 }
 
 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
@@ -1443,25 +1436,6 @@ static void cbq_destroy(struct Qdisc *sch)
 	qdisc_class_hash_destroy(&q->clhash);
 }
 
-static void cbq_put(struct Qdisc *sch, unsigned long arg)
-{
-	struct cbq_class *cl = (struct cbq_class *)arg;
-
-	if (--cl->refcnt == 0) {
-#ifdef CONFIG_NET_CLS_ACT
-		spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
-		struct cbq_sched_data *q = qdisc_priv(sch);
-
-		spin_lock_bh(root_lock);
-		if (q->rx_class == cl)
-			q->rx_class = NULL;
-		spin_unlock_bh(root_lock);
-#endif
-
-		cbq_destroy_class(sch, cl);
-	}
-}
-
 static int
 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca,
 		 unsigned long *arg)
@@ -1608,7 +1582,6 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **t
 
 	cl->R_tab = rtab;
 	rtab = NULL;
-	cl->refcnt = 1;
 	cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid);
 	if (!cl->q)
 		cl->q = &noop_qdisc;
@@ -1689,12 +1662,7 @@ static int cbq_delete(struct Qdisc *sch, unsigned long arg)
 	cbq_rmprio(q, cl);
 	sch_tree_unlock(sch);
 
-	BUG_ON(--cl->refcnt == 0);
-	/*
-	 * This shouldn't happen: we "hold" one cops->get() when called
-	 * from tc_ctl_tclass; the destroy method is done from cops->put().
-	 */
-
+	cbq_destroy_class(sch, cl);
 	return 0;
 }
 
@@ -1760,8 +1728,7 @@ static const struct Qdisc_class_ops cbq_class_ops = {
 	.graft		=	cbq_graft,
 	.leaf		=	cbq_leaf,
 	.qlen_notify	=	cbq_qlen_notify,
-	.get		=	cbq_get,
-	.put		=	cbq_put,
+	.find		=	cbq_find,
 	.change		=	cbq_change_class,
 	.delete		=	cbq_delete,
 	.walk		=	cbq_walk,

net/sched/sch_drr.c

@@ -20,7 +20,6 @@
 
 struct drr_class {
 	struct Qdisc_class_common	common;
-	unsigned int			refcnt;
 	unsigned int			filter_cnt;
 
 	struct gnet_stats_basic_packed		bstats;
@@ -111,7 +110,6 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	if (cl == NULL)
 		return -ENOBUFS;
 
-	cl->refcnt	   = 1;
 	cl->common.classid = classid;
 	cl->quantum	   = quantum;
 	cl->qdisc	   = qdisc_create_dflt(sch->dev_queue,
@@ -163,32 +161,15 @@ static int drr_delete_class(struct Qdisc *sch, unsigned long arg)
 	drr_purge_queue(cl);
 	qdisc_class_hash_remove(&q->clhash, &cl->common);
 
-	BUG_ON(--cl->refcnt == 0);
-	/*
-	 * This shouldn't happen: we "hold" one cops->get() when called
-	 * from tc_ctl_tclass; the destroy method is done from cops->put().
-	 */
-
 	sch_tree_unlock(sch);
-	return 0;
-}
-
-static unsigned long drr_get_class(struct Qdisc *sch, u32 classid)
-{
-	struct drr_class *cl = drr_find_class(sch, classid);
 
-	if (cl != NULL)
-		cl->refcnt++;
-
-	return (unsigned long)cl;
+	drr_destroy_class(sch, cl);
+	return 0;
 }
 
-static void drr_put_class(struct Qdisc *sch, unsigned long arg)
+static unsigned long drr_search_class(struct Qdisc *sch, u32 classid)
 {
-	struct drr_class *cl = (struct drr_class *)arg;
-
-	if (--cl->refcnt == 0)
-		drr_destroy_class(sch, cl);
+	return (unsigned long)drr_find_class(sch, classid);
 }
 
 static struct tcf_block *drr_tcf_block(struct Qdisc *sch, unsigned long cl)
@@ -478,8 +459,7 @@ static void drr_destroy_qdisc(struct Qdisc *sch)
 static const struct Qdisc_class_ops drr_class_ops = {
 	.change		= drr_change_class,
 	.delete		= drr_delete_class,
-	.get		= drr_get_class,
-	.put		= drr_put_class,
+	.find		= drr_search_class,
 	.tcf_block	= drr_tcf_block,
 	.bind_tcf	= drr_bind_tcf,
 	.unbind_tcf	= drr_unbind_tcf,

net/sched/sch_dsmark.c

@@ -85,21 +85,21 @@ static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
 	return p->q;
 }
 
-static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
+static unsigned long dsmark_find(struct Qdisc *sch, u32 classid)
 {
-	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n",
-		 __func__, sch, qdisc_priv(sch), classid);
-
 	return TC_H_MIN(classid) + 1;
 }
 
 static unsigned long dsmark_bind_filter(struct Qdisc *sch,
 					unsigned long parent, u32 classid)
 {
-	return dsmark_get(sch, classid);
+	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n",
+		 __func__, sch, qdisc_priv(sch), classid);
+
+	return dsmark_find(sch, classid);
 }
 
-static void dsmark_put(struct Qdisc *sch, unsigned long cl)
+static void dsmark_unbind_filter(struct Qdisc *sch, unsigned long cl)
 {
 }
 
@@ -469,14 +469,13 @@ static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
 static const struct Qdisc_class_ops dsmark_class_ops = {
 	.graft		=	dsmark_graft,
 	.leaf		=	dsmark_leaf,
-	.get		=	dsmark_get,
-	.put		=	dsmark_put,
+	.find		=	dsmark_find,
 	.change		=	dsmark_change,
 	.delete		=	dsmark_delete,
 	.walk		=	dsmark_walk,
 	.tcf_block	=	dsmark_tcf_block,
 	.bind_tcf	=	dsmark_bind_filter,
-	.unbind_tcf	=	dsmark_put,
+	.unbind_tcf	=	dsmark_unbind_filter,
 	.dump		=	dsmark_dump_class,
 };
 

net/sched/sch_fq_codel.c

@@ -579,7 +579,7 @@ static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg)
 	return NULL;
 }
 
-static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid)
+static unsigned long fq_codel_find(struct Qdisc *sch, u32 classid)
 {
 	return 0;
 }
@@ -592,7 +592,7 @@ static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent,
 	return 0;
 }
 
-static void fq_codel_put(struct Qdisc *q, unsigned long cl)
+static void fq_codel_unbind(struct Qdisc *q, unsigned long cl)
 {
 }
 
@@ -683,11 +683,10 @@ static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 static const struct Qdisc_class_ops fq_codel_class_ops = {
 	.leaf		=	fq_codel_leaf,
-	.get		=	fq_codel_get,
-	.put		=	fq_codel_put,
+	.find		=	fq_codel_find,
 	.tcf_block	=	fq_codel_tcf_block,
 	.bind_tcf	=	fq_codel_bind,
-	.unbind_tcf	=	fq_codel_put,
+	.unbind_tcf	=	fq_codel_unbind,
 	.dump		=	fq_codel_dump_class,
 	.dump_stats	=	fq_codel_dump_class_stats,
 	.walk		=	fq_codel_walk,

net/sched/sch_hfsc.c

@@ -110,7 +110,6 @@ enum hfsc_class_flags {
 
 struct hfsc_class {
 	struct Qdisc_class_common cl_common;
-	unsigned int	refcnt;		/* usage count */
 
 	struct gnet_stats_basic_packed bstats;
 	struct gnet_stats_queue qstats;
@@ -1045,7 +1044,6 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 		hfsc_change_usc(cl, usc, 0);
 
 	cl->cl_common.classid = classid;
-	cl->refcnt    = 1;
 	cl->sched     = q;
 	cl->cl_parent = parent;
 	cl->qdisc = qdisc_create_dflt(sch->dev_queue,
@@ -1101,13 +1099,9 @@ hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
 	hfsc_purge_queue(sch, cl);
 	qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
 
-	BUG_ON(--cl->refcnt == 0);
-	/*
-	 * This shouldn't happen: we "hold" one cops->get() when called
-	 * from tc_ctl_tclass; the destroy method is done from cops->put().
-	 */
-
 	sch_tree_unlock(sch);
+
+	hfsc_destroy_class(sch, cl);
 	return 0;
 }
 
@@ -1208,23 +1202,9 @@ hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
 }
 
 static unsigned long
-hfsc_get_class(struct Qdisc *sch, u32 classid)
-{
-	struct hfsc_class *cl = hfsc_find_class(classid, sch);
-
-	if (cl != NULL)
-		cl->refcnt++;
-
-	return (unsigned long)cl;
-}
-
-static void
-hfsc_put_class(struct Qdisc *sch, unsigned long arg)
+hfsc_search_class(struct Qdisc *sch, u32 classid)
 {
-	struct hfsc_class *cl = (struct hfsc_class *)arg;
-
-	if (--cl->refcnt == 0)
-		hfsc_destroy_class(sch, cl);
+	return (unsigned long)hfsc_find_class(classid, sch);
 }
 
 static unsigned long
@@ -1413,7 +1393,6 @@ hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
 		goto err_tcf;
 
 	q->root.cl_common.classid = sch->handle;
-	q->root.refcnt  = 1;
 	q->root.sched   = q;
 	q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
 					  sch->handle);
@@ -1661,8 +1640,7 @@ static const struct Qdisc_class_ops hfsc_class_ops = {
 	.graft		= hfsc_graft_class,
 	.leaf		= hfsc_class_leaf,
 	.qlen_notify	= hfsc_qlen_notify,
-	.get		= hfsc_get_class,
-	.put		= hfsc_put_class,
+	.find		= hfsc_search_class,
 	.bind_tcf	= hfsc_bind_tcf,
 	.unbind_tcf	= hfsc_unbind_tcf,
 	.tcf_block	= hfsc_tcf_block,

net/sched/sch_htb.c

@@ -107,7 +107,6 @@ struct htb_class {
 	struct tcf_proto __rcu	*filter_list;	/* class attached filters */
 	struct tcf_block	*block;
 	int			filter_cnt;
-	int			refcnt;		/* usage count of this class */
 
 	int			level;		/* our level (see above) */
 	unsigned int		children;
@@ -193,6 +192,10 @@ static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
 	return container_of(clc, struct htb_class, common);
 }
 
+static unsigned long htb_search(struct Qdisc *sch, u32 handle)
+{
+	return (unsigned long)htb_find(handle, sch);
+}
 /**
  * htb_classify - classify a packet into class
  *
@@ -1189,14 +1192,6 @@ static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg)
 	htb_deactivate(qdisc_priv(sch), cl);
 }
 
-static unsigned long htb_get(struct Qdisc *sch, u32 classid)
-{
-	struct htb_class *cl = htb_find(classid, sch);
-	if (cl)
-		cl->refcnt++;
-	return (unsigned long)cl;
-}
-
 static inline int htb_parent_last_child(struct htb_class *cl)
 {
 	if (!cl->parent)
@@ -1316,22 +1311,10 @@ static int htb_delete(struct Qdisc *sch, unsigned long arg)
 	if (last_child)
 		htb_parent_to_leaf(q, cl, new_q);
 
-	BUG_ON(--cl->refcnt == 0);
-	/*
-	 * This shouldn't happen: we "hold" one cops->get() when called
-	 * from tc_ctl_tclass; the destroy method is done from cops->put().
-	 */
-
 	sch_tree_unlock(sch);
-	return 0;
-}
 
-static void htb_put(struct Qdisc *sch, unsigned long arg)
-{
-	struct htb_class *cl = (struct htb_class *)arg;
-
-	if (--cl->refcnt == 0)
-		htb_destroy_class(sch, cl);
+	htb_destroy_class(sch, cl);
+	return 0;
 }
 
 static int htb_change_class(struct Qdisc *sch, u32 classid,
@@ -1422,7 +1405,6 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 			}
 		}
 
-		cl->refcnt = 1;
 		cl->children = 0;
 		INIT_LIST_HEAD(&cl->un.leaf.drop_list);
 		RB_CLEAR_NODE(&cl->pq_node);
@@ -1598,8 +1580,7 @@ static const struct Qdisc_class_ops htb_class_ops = {
 	.graft		=	htb_graft,
 	.leaf		=	htb_leaf,
 	.qlen_notify	=	htb_qlen_notify,
-	.get		=	htb_get,
-	.put		=	htb_put,
+	.find		=	htb_search,
 	.change		=	htb_change_class,
 	.delete		=	htb_delete,
 	.walk		=	htb_walk,

net/sched/sch_ingress.c

@@ -27,7 +27,7 @@ static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
 	return NULL;
 }
 
-static unsigned long ingress_get(struct Qdisc *sch, u32 classid)
+static unsigned long ingress_find(struct Qdisc *sch, u32 classid)
 {
 	return TC_H_MIN(classid) + 1;
 }
@@ -35,10 +35,10 @@ static unsigned long ingress_get(struct Qdisc *sch, u32 classid)
 static unsigned long ingress_bind_filter(struct Qdisc *sch,
 					 unsigned long parent, u32 classid)
 {
-	return ingress_get(sch, classid);
+	return ingress_find(sch, classid);
 }
 
-static void ingress_put(struct Qdisc *sch, unsigned long cl)
+static void ingress_unbind_filter(struct Qdisc *sch, unsigned long cl)
 {
 }
 
@@ -94,12 +94,11 @@ static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
 
 static const struct Qdisc_class_ops ingress_class_ops = {
 	.leaf		=	ingress_leaf,
-	.get		=	ingress_get,
-	.put		=	ingress_put,
+	.find		=	ingress_find,
 	.walk		=	ingress_walk,
 	.tcf_block	=	ingress_tcf_block,
 	.bind_tcf	=	ingress_bind_filter,
-	.unbind_tcf	=	ingress_put,
+	.unbind_tcf	=	ingress_unbind_filter,
 };
 
 static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
@@ -117,7 +116,7 @@ struct clsact_sched_data {
 	struct tcf_block *egress_block;
 };
 
-static unsigned long clsact_get(struct Qdisc *sch, u32 classid)
+static unsigned long clsact_find(struct Qdisc *sch, u32 classid)
 {
 	switch (TC_H_MIN(classid)) {
 	case TC_H_MIN(TC_H_MIN_INGRESS):
@@ -131,7 +130,7 @@ static unsigned long clsact_get(struct Qdisc *sch, u32 classid)
 static unsigned long clsact_bind_filter(struct Qdisc *sch,
 					unsigned long parent, u32 classid)
 {
-	return clsact_get(sch, classid);
+	return clsact_find(sch, classid);
 }
 
 static struct tcf_block *clsact_tcf_block(struct Qdisc *sch, unsigned long cl)
@@ -183,12 +182,11 @@ static void clsact_destroy(struct Qdisc *sch)
 
 static const struct Qdisc_class_ops clsact_class_ops = {
 	.leaf		=	ingress_leaf,
-	.get		=	clsact_get,
-	.put		=	ingress_put,
+	.find		=	clsact_find,
 	.walk		=	ingress_walk,
 	.tcf_block	=	clsact_tcf_block,
 	.bind_tcf	=	clsact_bind_filter,
-	.unbind_tcf	=	ingress_put,
+	.unbind_tcf	=	ingress_unbind_filter,
 };
 
 static struct Qdisc_ops clsact_qdisc_ops __read_mostly = {

net/sched/sch_mq.c

@@ -165,7 +165,7 @@ static struct Qdisc *mq_leaf(struct Qdisc *sch, unsigned long cl)
 	return dev_queue->qdisc_sleeping;
 }
 
-static unsigned long mq_get(struct Qdisc *sch, u32 classid)
+static unsigned long mq_find(struct Qdisc *sch, u32 classid)
 {
 	unsigned int ntx = TC_H_MIN(classid);
 
@@ -174,10 +174,6 @@ static unsigned long mq_get(struct Qdisc *sch, u32 classid)
 	return ntx;
 }
 
-static void mq_put(struct Qdisc *sch, unsigned long cl)
-{
-}
-
 static int mq_dump_class(struct Qdisc *sch, unsigned long cl,
 			 struct sk_buff *skb, struct tcmsg *tcm)
 {
@@ -223,8 +219,7 @@ static const struct Qdisc_class_ops mq_class_ops = {
 	.select_queue	= mq_select_queue,
 	.graft		= mq_graft,
 	.leaf		= mq_leaf,
-	.get		= mq_get,
-	.put		= mq_put,
+	.find		= mq_find,
 	.walk		= mq_walk,
 	.dump		= mq_dump_class,
 	.dump_stats	= mq_dump_class_stats,

net/sched/sch_mqprio.c

@@ -277,7 +277,7 @@ static struct Qdisc *mqprio_leaf(struct Qdisc *sch, unsigned long cl)
 	return dev_queue->qdisc_sleeping;
 }
 
-static unsigned long mqprio_get(struct Qdisc *sch, u32 classid)
+static unsigned long mqprio_find(struct Qdisc *sch, u32 classid)
 {
 	struct net_device *dev = qdisc_dev(sch);
 	unsigned int ntx = TC_H_MIN(classid);
@@ -287,10 +287,6 @@ static unsigned long mqprio_get(struct Qdisc *sch, u32 classid)
 	return ntx;
 }
 
-static void mqprio_put(struct Qdisc *sch, unsigned long cl)
-{
-}
-
 static int mqprio_dump_class(struct Qdisc *sch, unsigned long cl,
 			 struct sk_buff *skb, struct tcmsg *tcm)
 {
@@ -403,8 +399,7 @@ static void mqprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 static const struct Qdisc_class_ops mqprio_class_ops = {
 	.graft		= mqprio_graft,
 	.leaf		= mqprio_leaf,
-	.get		= mqprio_get,
-	.put		= mqprio_put,
+	.find		= mqprio_find,
 	.walk		= mqprio_walk,
 	.dump		= mqprio_dump_class,
 	.dump_stats	= mqprio_dump_class_stats,

net/sched/sch_multiq.c

@@ -306,7 +306,7 @@ multiq_leaf(struct Qdisc *sch, unsigned long arg)
 	return q->queues[band];
 }
 
-static unsigned long multiq_get(struct Qdisc *sch, u32 classid)
+static unsigned long multiq_find(struct Qdisc *sch, u32 classid)
 {
 	struct multiq_sched_data *q = qdisc_priv(sch);
 	unsigned long band = TC_H_MIN(classid);
@@ -319,11 +319,11 @@ static unsigned long multiq_get(struct Qdisc *sch, u32 classid)
 static unsigned long multiq_bind(struct Qdisc *sch, unsigned long parent,
 				 u32 classid)
 {
-	return multiq_get(sch, classid);
+	return multiq_find(sch, classid);
 }
 
 
-static void multiq_put(struct Qdisc *q, unsigned long cl)
+static void multiq_unbind(struct Qdisc *q, unsigned long cl)
 {
 }
 
@@ -385,12 +385,11 @@ static struct tcf_block *multiq_tcf_block(struct Qdisc *sch, unsigned long cl)
 static const struct Qdisc_class_ops multiq_class_ops = {
 	.graft		=	multiq_graft,
 	.leaf		=	multiq_leaf,
-	.get		=	multiq_get,
-	.put		=	multiq_put,
+	.find		=	multiq_find,
 	.walk		=	multiq_walk,
 	.tcf_block	=	multiq_tcf_block,
 	.bind_tcf	=	multiq_bind,
-	.unbind_tcf	=	multiq_put,
+	.unbind_tcf	=	multiq_unbind,
 	.dump		=	multiq_dump_class,
 	.dump_stats	=	multiq_dump_class_stats,
 };

net/sched/sch_netem.c

@@ -1096,15 +1096,11 @@ static struct Qdisc *netem_leaf(struct Qdisc *sch, unsigned long arg)
 	return q->qdisc;
 }
 
-static unsigned long netem_get(struct Qdisc *sch, u32 classid)
+static unsigned long netem_find(struct Qdisc *sch, u32 classid)
 {
 	return 1;
 }
 
-static void netem_put(struct Qdisc *sch, unsigned long arg)
-{
-}
-
 static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 {
 	if (!walker->stop) {
@@ -1120,8 +1116,7 @@ static void netem_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 static const struct Qdisc_class_ops netem_class_ops = {
 	.graft		=	netem_graft,
 	.leaf		=	netem_leaf,
-	.get		=	netem_get,
-	.put		=	netem_put,
+	.find		=	netem_find,
 	.walk		=	netem_walk,
 	.dump		=	netem_dump_class,
 };

net/sched/sch_prio.c

@@ -260,7 +260,7 @@ prio_leaf(struct Qdisc *sch, unsigned long arg)
 	return q->queues[band];
 }
 
-static unsigned long prio_get(struct Qdisc *sch, u32 classid)
+static unsigned long prio_find(struct Qdisc *sch, u32 classid)
 {
 	struct prio_sched_data *q = qdisc_priv(sch);
 	unsigned long band = TC_H_MIN(classid);
@@ -272,11 +272,11 @@ static unsigned long prio_get(struct Qdisc *sch, u32 classid)
 
 static unsigned long prio_bind(struct Qdisc *sch, unsigned long parent, u32 classid)
 {
-	return prio_get(sch, classid);
+	return prio_find(sch, classid);
 }
 
 
-static void prio_put(struct Qdisc *q, unsigned long cl)
+static void prio_unbind(struct Qdisc *q, unsigned long cl)
 {
 }
 
@@ -338,12 +338,11 @@ static struct tcf_block *prio_tcf_block(struct Qdisc *sch, unsigned long cl)
 static const struct Qdisc_class_ops prio_class_ops = {
 	.graft		=	prio_graft,
 	.leaf		=	prio_leaf,
-	.get		=	prio_get,
-	.put		=	prio_put,
+	.find		=	prio_find,
 	.walk		=	prio_walk,
 	.tcf_block	=	prio_tcf_block,
 	.bind_tcf	=	prio_bind,
-	.unbind_tcf	=	prio_put,
+	.unbind_tcf	=	prio_unbind,
 	.dump		=	prio_dump_class,
 	.dump_stats	=	prio_dump_class_stats,
 };

net/sched/sch_qfq.c

@@ -132,7 +132,6 @@ struct qfq_aggregate;
 struct qfq_class {
 	struct Qdisc_class_common common;
 
-	unsigned int refcnt;
 	unsigned int filter_cnt;
 
 	struct gnet_stats_basic_packed bstats;
@@ -477,7 +476,6 @@ static int qfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 	if (cl == NULL)
 		return -ENOBUFS;
 
-	cl->refcnt = 1;
 	cl->common.classid = classid;
 	cl->deficit = lmax;
 
@@ -555,32 +553,15 @@ static int qfq_delete_class(struct Qdisc *sch, unsigned long arg)
 	qfq_purge_queue(cl);
 	qdisc_class_hash_remove(&q->clhash, &cl->common);
 
-	BUG_ON(--cl->refcnt == 0);
-	/*
-	 * This shouldn't happen: we "hold" one cops->get() when called
-	 * from tc_ctl_tclass; the destroy method is done from cops->put().
-	 */
-
 	sch_tree_unlock(sch);
-	return 0;
-}
-
-static unsigned long qfq_get_class(struct Qdisc *sch, u32 classid)
-{
-	struct qfq_class *cl = qfq_find_class(sch, classid);
-
-	if (cl != NULL)
-		cl->refcnt++;
 
-	return (unsigned long)cl;
+	qfq_destroy_class(sch, cl);
+	return 0;
 }
 
-static void qfq_put_class(struct Qdisc *sch, unsigned long arg)
+static unsigned long qfq_search_class(struct Qdisc *sch, u32 classid)
 {
-	struct qfq_class *cl = (struct qfq_class *)arg;
-
-	if (--cl->refcnt == 0)
-		qfq_destroy_class(sch, cl);
+	return (unsigned long)qfq_find_class(sch, classid);
 }
 
 static struct tcf_block *qfq_tcf_block(struct Qdisc *sch, unsigned long cl)
@@ -1510,8 +1491,7 @@ static void qfq_destroy_qdisc(struct Qdisc *sch)
 static const struct Qdisc_class_ops qfq_class_ops = {
 	.change		= qfq_change_class,
 	.delete		= qfq_delete_class,
-	.get		= qfq_get_class,
-	.put		= qfq_put_class,
+	.find		= qfq_search_class,
 	.tcf_block	= qfq_tcf_block,
 	.bind_tcf	= qfq_bind_tcf,
 	.unbind_tcf	= qfq_unbind_tcf,

net/sched/sch_red.c

@@ -311,15 +311,11 @@ static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg)
 	return q->qdisc;
 }
 
-static unsigned long red_get(struct Qdisc *sch, u32 classid)
+static unsigned long red_find(struct Qdisc *sch, u32 classid)
 {
 	return 1;
 }
 
-static void red_put(struct Qdisc *sch, unsigned long arg)
-{
-}
-
 static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 {
 	if (!walker->stop) {
@@ -335,8 +331,7 @@ static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 static const struct Qdisc_class_ops red_class_ops = {
 	.graft		=	red_graft,
 	.leaf		=	red_leaf,
-	.get		=	red_get,
-	.put		=	red_put,
+	.find		=	red_find,
 	.walk		=	red_walk,
 	.dump		=	red_dump_class,
 };

net/sched/sch_sfb.c

@@ -632,12 +632,12 @@ static struct Qdisc *sfb_leaf(struct Qdisc *sch, unsigned long arg)
 	return q->qdisc;
 }
 
-static unsigned long sfb_get(struct Qdisc *sch, u32 classid)
+static unsigned long sfb_find(struct Qdisc *sch, u32 classid)
 {
 	return 1;
 }
 
-static void sfb_put(struct Qdisc *sch, unsigned long arg)
+static void sfb_unbind(struct Qdisc *sch, unsigned long arg)
 {
 }
 
@@ -683,14 +683,13 @@ static unsigned long sfb_bind(struct Qdisc *sch, unsigned long parent,
 static const struct Qdisc_class_ops sfb_class_ops = {
 	.graft		=	sfb_graft,
 	.leaf		=	sfb_leaf,
-	.get		=	sfb_get,
-	.put		=	sfb_put,
+	.find		=	sfb_find,
 	.change		=	sfb_change_class,
 	.delete		=	sfb_delete,
 	.walk		=	sfb_walk,
 	.tcf_block	=	sfb_tcf_block,
 	.bind_tcf	=	sfb_bind,
-	.unbind_tcf	=	sfb_put,
+	.unbind_tcf	=	sfb_unbind,
 	.dump		=	sfb_dump_class,
 };
 

net/sched/sch_sfq.c

@@ -808,7 +808,7 @@ static struct Qdisc *sfq_leaf(struct Qdisc *sch, unsigned long arg)
 	return NULL;
 }
 
-static unsigned long sfq_get(struct Qdisc *sch, u32 classid)
+static unsigned long sfq_find(struct Qdisc *sch, u32 classid)
 {
 	return 0;
 }
@@ -821,7 +821,7 @@ static unsigned long sfq_bind(struct Qdisc *sch, unsigned long parent,
 	return 0;
 }
 
-static void sfq_put(struct Qdisc *q, unsigned long cl)
+static void sfq_unbind(struct Qdisc *q, unsigned long cl)
 {
 }
 
@@ -885,11 +885,10 @@ static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 
 static const struct Qdisc_class_ops sfq_class_ops = {
 	.leaf		=	sfq_leaf,
-	.get		=	sfq_get,
-	.put		=	sfq_put,
+	.find		=	sfq_find,
 	.tcf_block	=	sfq_tcf_block,
 	.bind_tcf	=	sfq_bind,
-	.unbind_tcf	=	sfq_put,
+	.unbind_tcf	=	sfq_unbind,
 	.dump		=	sfq_dump_class,
 	.dump_stats	=	sfq_dump_class_stats,
 	.walk		=	sfq_walk,

net/sched/sch_tbf.c

@@ -510,15 +510,11 @@ static struct Qdisc *tbf_leaf(struct Qdisc *sch, unsigned long arg)
 	return q->qdisc;
 }
 
-static unsigned long tbf_get(struct Qdisc *sch, u32 classid)
+static unsigned long tbf_find(struct Qdisc *sch, u32 classid)
 {
 	return 1;
 }
 
-static void tbf_put(struct Qdisc *sch, unsigned long arg)
-{
-}
-
 static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 {
 	if (!walker->stop) {
@@ -534,8 +530,7 @@ static void tbf_walk(struct Qdisc *sch, struct qdisc_walker *walker)
 static const struct Qdisc_class_ops tbf_class_ops = {
 	.graft		=	tbf_graft,
 	.leaf		=	tbf_leaf,
-	.get		=	tbf_get,
-	.put		=	tbf_put,
+	.find		=	tbf_find,
 	.walk		=	tbf_walk,
 	.dump		=	tbf_dump_class,
 };