[PATCH] sysfs: (driver/base) if show/store is missing return -EIO

sysfs: fix drivers/base so if an attribute doesn't implement
       show or store method read/write will return -EIO
       instead of 0.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/base/bus.c

@@ -36,7 +36,7 @@ drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
 {
 	struct driver_attribute * drv_attr = to_drv_attr(attr);
 	struct device_driver * drv = to_driver(kobj);
-	ssize_t ret = 0;
+	ssize_t ret = -EIO;
 
 	if (drv_attr->show)
 		ret = drv_attr->show(drv, buf);
@@ -49,7 +49,7 @@ drv_attr_store(struct kobject * kobj, struct attribute * attr,
 {
 	struct driver_attribute * drv_attr = to_drv_attr(attr);
 	struct device_driver * drv = to_driver(kobj);
-	ssize_t ret = 0;
+	ssize_t ret = -EIO;
 
 	if (drv_attr->store)
 		ret = drv_attr->store(drv, buf, count);

drivers/base/class.c

@@ -26,7 +26,7 @@ class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
 {
 	struct class_attribute * class_attr = to_class_attr(attr);
 	struct class * dc = to_class(kobj);
-	ssize_t ret = 0;
+	ssize_t ret = -EIO;
 
 	if (class_attr->show)
 		ret = class_attr->show(dc, buf);
@@ -39,7 +39,7 @@ class_attr_store(struct kobject * kobj, struct attribute * attr,
 {
 	struct class_attribute * class_attr = to_class_attr(attr);
 	struct class * dc = to_class(kobj);
-	ssize_t ret = 0;
+	ssize_t ret = -EIO;
 
 	if (class_attr->store)
 		ret = class_attr->store(dc, buf, count);

drivers/base/core.c

@@ -36,7 +36,7 @@ dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
 {
 	struct device_attribute * dev_attr = to_dev_attr(attr);
 	struct device * dev = to_dev(kobj);
-	ssize_t ret = 0;
+	ssize_t ret = -EIO;
 
 	if (dev_attr->show)
 		ret = dev_attr->show(dev, buf);
@@ -49,7 +49,7 @@ dev_attr_store(struct kobject * kobj, struct attribute * attr,
 {
 	struct device_attribute * dev_attr = to_dev_attr(attr);
 	struct device * dev = to_dev(kobj);
-	ssize_t ret = 0;
+	ssize_t ret = -EIO;
 
 	if (dev_attr->store)
 		ret = dev_attr->store(dev, buf, count);

drivers/base/sys.c

@@ -37,7 +37,7 @@ sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
 
 	if (sysdev_attr->show)
 		return sysdev_attr->show(sysdev, buffer);
-	return 0;
+	return -EIO;
 }
 
 
@@ -50,7 +50,7 @@ sysdev_store(struct kobject * kobj, struct attribute * attr,
 
 	if (sysdev_attr->store)
 		return sysdev_attr->store(sysdev, buffer, count);
-	return 0;
+	return -EIO;
 }
 
 static struct sysfs_ops sysfs_ops = {