[PATCH] Add a klist to struct bus_type for its drivers.

- Use it in bus_for_each_drv().
- Use the klist spinlock instead of the bus rwsem.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/device.h

@@ -53,6 +53,7 @@ struct bus_type {
 	struct kset		drivers;
 	struct kset		devices;
 	struct klist		klist_devices;
+	struct klist		klist_drivers;
 
 	struct bus_attribute	* bus_attrs;
 	struct device_attribute	* dev_attrs;
@@ -105,6 +106,7 @@ struct device_driver {
 	struct completion	unloaded;
 	struct kobject		kobj;
 	struct list_head	devices;
+	struct klist_node	knode_bus;
 
 	struct module		* owner;