--- zzzz-none-000/linux-3.10.107/drivers/xen/xen-balloon.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/xen/xen-balloon.c	2021-02-04 17:41:59.000000000 +0000
@@ -30,6 +30,8 @@
  * IN THE SOFTWARE.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/capability.h>
@@ -81,7 +83,7 @@
 
 	err = register_xenbus_watch(&target_watch);
 	if (err)
-		printk(KERN_ERR "Failed to set balloon watcher\n");
+		pr_err("Failed to set balloon watcher\n");
 
 	return NOTIFY_DONE;
 }
@@ -95,7 +97,7 @@
 	if (!xen_domain())
 		return -ENODEV;
 
-	pr_info("xen-balloon: Initialising balloon driver.\n");
+	pr_info("Initialising balloon driver\n");
 
 	register_balloon(&balloon_dev);
 
@@ -191,13 +193,18 @@
 		   show_target, store_target);
 
 
-static struct device_attribute *balloon_attrs[] = {
-	&dev_attr_target_kb,
-	&dev_attr_target,
-	&dev_attr_schedule_delay.attr,
-	&dev_attr_max_schedule_delay.attr,
-	&dev_attr_retry_count.attr,
-	&dev_attr_max_retry_count.attr
+static struct attribute *balloon_attrs[] = {
+	&dev_attr_target_kb.attr,
+	&dev_attr_target.attr,
+	&dev_attr_schedule_delay.attr.attr,
+	&dev_attr_max_schedule_delay.attr.attr,
+	&dev_attr_retry_count.attr.attr,
+	&dev_attr_max_retry_count.attr.attr,
+	NULL
+};
+
+static const struct attribute_group balloon_group = {
+	.attrs = balloon_attrs
 };
 
 static struct attribute *balloon_info_attrs[] = {
@@ -212,6 +219,12 @@
 	.attrs = balloon_info_attrs
 };
 
+static const struct attribute_group *balloon_groups[] = {
+	&balloon_group,
+	&balloon_info_group,
+	NULL
+};
+
 static struct bus_type balloon_subsys = {
 	.name = BALLOON_CLASS_NAME,
 	.dev_name = BALLOON_CLASS_NAME,
@@ -219,7 +232,7 @@
 
 static int register_balloon(struct device *dev)
 {
-	int i, error;
+	int error;
 
 	error = subsys_system_register(&balloon_subsys, NULL);
 	if (error)
@@ -227,6 +240,7 @@
 
 	dev->id = 0;
 	dev->bus = &balloon_subsys;
+	dev->groups = balloon_groups;
 
 	error = device_register(dev);
 	if (error) {
@@ -234,24 +248,7 @@
 		return error;
 	}
 
-	for (i = 0; i < ARRAY_SIZE(balloon_attrs); i++) {
-		error = device_create_file(dev, balloon_attrs[i]);
-		if (error)
-			goto fail;
-	}
-
-	error = sysfs_create_group(&dev->kobj, &balloon_info_group);
-	if (error)
-		goto fail;
-
 	return 0;
-
- fail:
-	while (--i >= 0)
-		device_remove_file(dev, balloon_attrs[i]);
-	device_unregister(dev);
-	bus_unregister(&balloon_subsys);
-	return error;
 }
 
 MODULE_LICENSE("GPL");