[PATCH] Add a klist to struct device_driver for the devices bound to it.

- Use it in driver_for_each_device() instead of the regular list_head and stop using
  the bus's rwsem for protection.
- Use driver_for_each_device() in driver_detach() so we don't deadlock on the
  bus's rwsem.
- Remove ->devices.
- Move klist access and sysfs link access out from under device's semaphore, since
  they're synchronized through other means.

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

1 files changed, 19 insertions, 15 deletions

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index b709b1e0cb2a..47cbb5641235 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -40,7 +40,7 @@ void device_bind_driver(struct device * dev)
 {
 	pr_debug("bound device '%s' to driver '%s'\n",
 		 dev->bus_id, dev->driver->name);
-	list_add_tail(&dev->driver_list, &dev->driver->devices);
+	klist_add_tail(&dev->driver->klist_devices, &dev->knode_driver);
 	sysfs_create_link(&dev->driver->kobj, &dev->kobj,
 			  kobject_name(&dev->kobj));
 	sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver");
@@ -164,31 +164,35 @@ void driver_attach(struct device_driver * drv)
  */
 void device_release_driver(struct device * dev)
 {
-	struct device_driver * drv;
+	struct device_driver * drv = dev->driver;
+
+	if (!drv)
+		return;
+
+	sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
+	sysfs_remove_link(&dev->kobj, "driver");
+	klist_remove(&dev->knode_driver);
 
 	down(&dev->sem);
-	drv = dev->driver;
-	if (drv) {
-		sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
-		sysfs_remove_link(&dev->kobj, "driver");
-		list_del_init(&dev->driver_list);
-		if (drv->remove)
-			drv->remove(dev);
-		dev->driver = NULL;
-	}
+	if (drv->remove)
+		drv->remove(dev);
+	dev->driver = NULL;
 	up(&dev->sem);
 }
 
+static int __remove_driver(struct device * dev, void * unused)
+{
+	device_release_driver(dev);
+	return 0;
+}
+
 /**
  * driver_detach - detach driver from all devices it controls.
  * @drv: driver.
  */
 void driver_detach(struct device_driver * drv)
 {
-	while (!list_empty(&drv->devices)) {
-		struct device * dev = container_of(drv->devices.next, struct device, driver_list);
-		device_release_driver(dev);
-	}
+	driver_for_each_device(drv, NULL, NULL, __remove_driver);
 }