Input: serio_raw - use kref instead of rolling out its own refcounting

Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/serio/serio_raw.c

@@ -9,6 +9,7 @@
  * the Free Software Foundation.
  */
 
+#include <linux/kref.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/poll.h>
@@ -33,7 +34,7 @@ struct serio_raw {
 	unsigned int tail, head;
 
 	char name[16];
-	unsigned int refcnt;
+	struct kref kref;
 	struct serio *serio;
 	struct miscdevice dev;
 	wait_queue_head_t wait;
@@ -104,7 +105,7 @@ static int serio_raw_open(struct inode *inode, struct file *file)
 	list->serio_raw = serio_raw;
 	file->private_data = list;
 
-	serio_raw->refcnt++;
+	kref_get(&serio_raw->kref);
 	list_add_tail(&list->node, &serio_raw->list);
 
 out:
@@ -112,17 +113,14 @@ static int serio_raw_open(struct inode *inode, struct file *file)
 	return retval;
 }
 
-static int serio_raw_cleanup(struct serio_raw *serio_raw)
+static void serio_raw_cleanup(struct kref *kref)
 {
-	if (--serio_raw->refcnt == 0) {
+	struct serio_raw *serio_raw =
+			container_of(kref, struct serio_raw, kref);
+
 	misc_deregister(&serio_raw->dev);
 	list_del_init(&serio_raw->node);
 	kfree(serio_raw);
-
-		return 1;
-	}
-
-	return 0;
 }
 
 static int serio_raw_release(struct inode *inode, struct file *file)
@@ -132,7 +130,7 @@ static int serio_raw_release(struct inode *inode, struct file *file)
 
 	mutex_lock(&serio_raw_mutex);
 
-	serio_raw_cleanup(serio_raw);
+	kref_put(&serio_raw->kref, serio_raw_cleanup);
 
 	mutex_unlock(&serio_raw_mutex);
 	return 0;
@@ -283,7 +281,7 @@ static int serio_raw_connect(struct serio *serio, struct serio_driver *drv)
 	mutex_lock(&serio_raw_mutex);
 
 	snprintf(serio_raw->name, sizeof(serio_raw->name), "serio_raw%d", serio_raw_no++);
-	serio_raw->refcnt = 1;
+	kref_init(&serio_raw->kref);
 	serio_raw->serio = serio;
 	INIT_LIST_HEAD(&serio_raw->list);
 	init_waitqueue_head(&serio_raw->wait);
@@ -357,8 +355,8 @@ static void serio_raw_disconnect(struct serio *serio)
 	serio_set_drvdata(serio, NULL);
 
 	serio_raw->serio = NULL;
-	if (!serio_raw_cleanup(serio_raw))
 	wake_up_interruptible(&serio_raw->wait);
+	kref_put(&serio_raw->kref, serio_raw_cleanup);
 
 	mutex_unlock(&serio_raw_mutex);
 }