[PKT_SCHED]: Cleanup qdisc creation and alignment macros

Adds qdisc_alloc() to share code between qdisc_create()
and qdisc_create_dflt(). Hides the qdisc alignment behind
macros and makes use of them.

Signed-off-by: Thomas Graf <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/pkt_sched.h

···
 
 extern rwlock_t qdisc_tree_lock;
 
-#define	QDISC_ALIGN		32
-#define	QDISC_ALIGN_CONST	(QDISC_ALIGN - 1)
+#define QDISC_ALIGNTO		32
+#define QDISC_ALIGN(len)	(((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
 
 static inline void *qdisc_priv(struct Qdisc *q)
 {
-	return (char *)q + ((sizeof(struct Qdisc) + QDISC_ALIGN_CONST)
-			      & ~QDISC_ALIGN_CONST);
+	return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
 }
 
 /* 

include/net/sch_generic.h

···
 extern void dev_deactivate(struct net_device *dev);
 extern void qdisc_reset(struct Qdisc *qdisc);
 extern void qdisc_destroy(struct Qdisc *qdisc);
+extern struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops);
 extern struct Qdisc *qdisc_create_dflt(struct net_device *dev,
 				       struct Qdisc_ops *ops);
 

net/sched/sch_api.c

···
 {
 	int err;
 	struct rtattr *kind = tca[TCA_KIND-1];
-	void *p = NULL;
 	struct Qdisc *sch;
 	struct Qdisc_ops *ops;
-	int size;
 
 	ops = qdisc_lookup_ops(kind);
 #ifdef CONFIG_KMOD
···
 	if (ops == NULL)
 		goto err_out;
 
-	/* ensure that the Qdisc and the private data are 32-byte aligned */
-	size = ((sizeof(*sch) + QDISC_ALIGN_CONST) & ~QDISC_ALIGN_CONST);
-	size += ops->priv_size + QDISC_ALIGN_CONST;
-
-	p = kmalloc(size, GFP_KERNEL);
-	err = -ENOBUFS;
-	if (!p)
+	sch = qdisc_alloc(dev, ops);
+	if (IS_ERR(sch)) {
+		err = PTR_ERR(sch);
 		goto err_out2;
-	memset(p, 0, size);
-	sch = (struct Qdisc *)(((unsigned long)p + QDISC_ALIGN_CONST)
-	                       & ~QDISC_ALIGN_CONST);
-	sch->padded = (char *)sch - (char *)p;
+	}
 
-	INIT_LIST_HEAD(&sch->list);
-	skb_queue_head_init(&sch->q);
-
-	if (handle == TC_H_INGRESS)
+	if (handle == TC_H_INGRESS) {
 		sch->flags |= TCQ_F_INGRESS;
-
-	sch->ops = ops;
-	sch->enqueue = ops->enqueue;
-	sch->dequeue = ops->dequeue;
-	sch->dev = dev;
-	dev_hold(dev);
-	atomic_set(&sch->refcnt, 1);
-	sch->stats_lock = &dev->queue_lock;
-	if (handle == 0) {
+		handle = TC_H_MAKE(TC_H_INGRESS, 0);
+	} else if (handle == 0) {
 		handle = qdisc_alloc_handle(dev);
 		err = -ENOMEM;
 		if (handle == 0)
 			goto err_out3;
 	}
 
-	if (handle == TC_H_INGRESS)
-                sch->handle =TC_H_MAKE(TC_H_INGRESS, 0);
-        else
-                sch->handle = handle;
+	sch->handle = handle;
 
 	if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS-1])) == 0) {
 		qdisc_lock_tree(dev);
···
 	}
 err_out3:
 	dev_put(dev);
+	kfree((char *) sch - sch->padded);
 err_out2:
 	module_put(ops->owner);
 err_out:
 	*errp = err;
-	if (p)
-		kfree(p);
 	return NULL;
 }
 

net/sched/sch_generic.c

···
 	.owner		=	THIS_MODULE,
 };
 
-struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
+struct Qdisc *qdisc_alloc(struct net_device *dev, struct Qdisc_ops *ops)
 {
 	void *p;
 	struct Qdisc *sch;
-	int size;
+	unsigned int size;
+	int err = -ENOBUFS;
 
 	/* ensure that the Qdisc and the private data are 32-byte aligned */
-	size = ((sizeof(*sch) + QDISC_ALIGN_CONST) & ~QDISC_ALIGN_CONST);
-	size += ops->priv_size + QDISC_ALIGN_CONST;
+	size = QDISC_ALIGN(sizeof(*sch));
+	size += ops->priv_size + (QDISC_ALIGNTO - 1);
 
 	p = kmalloc(size, GFP_KERNEL);
 	if (!p)
-		return NULL;
+		goto errout;
 	memset(p, 0, size);
-
-	sch = (struct Qdisc *)(((unsigned long)p + QDISC_ALIGN_CONST) 
-			       & ~QDISC_ALIGN_CONST);
-	sch->padded = (char *)sch - (char *)p;
+	sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
+	sch->padded = (char *) sch - (char *) p;
 
 	INIT_LIST_HEAD(&sch->list);
 	skb_queue_head_init(&sch->q);
···
 	dev_hold(dev);
 	sch->stats_lock = &dev->queue_lock;
 	atomic_set(&sch->refcnt, 1);
+
+	return sch;
+errout:
+	return ERR_PTR(-err);
+}
+
+struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
+{
+	struct Qdisc *sch;
+	
+	sch = qdisc_alloc(dev, ops);
+	if (IS_ERR(sch))
+		goto errout;
+
 	if (!ops->init || ops->init(sch, NULL) == 0)
 		return sch;
 
-	dev_put(dev);
-	kfree(p);
+errout:
 	return NULL;
 }
 
···
 EXPORT_SYMBOL(noop_qdisc);
 EXPORT_SYMBOL(noop_qdisc_ops);
 EXPORT_SYMBOL(qdisc_create_dflt);
+EXPORT_SYMBOL(qdisc_alloc);
 EXPORT_SYMBOL(qdisc_destroy);
 EXPORT_SYMBOL(qdisc_reset);
 EXPORT_SYMBOL(qdisc_restart);