Kobject: auto-cleanup on final unref
We save the current state in the object itself, so we can do proper
cleanup when the last reference is dropped.
If the initial reference is dropped, the object will be removed from
sysfs if needed, if an "add" event was sent, "remove" will be send, and
the allocated resources are released.
This allows us to clean up some driver core usage as well as allowing us
to do other such changes to the rest of the kernel.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 675a719..d5d542d 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -576,8 +576,8 @@
/*
* If we have no parent, we live in "virtual".
- * Class-devices with a bus-device as parent, live
- * in a class-directory to prevent namespace collisions.
+ * Class-devices with a non class-device as parent, live
+ * in a "glue" directory to prevent namespace collisions.
*/
if (parent == NULL)
parent_kobj = virtual_device_parent(dev);
@@ -607,8 +607,7 @@
kobject_put(k);
return NULL;
}
- /* Do not emit a uevent, as it's not needed for this
- * "class glue" directory. */
+ /* do not emit an uevent for this simple "glue" directory */
return k;
}
@@ -619,30 +618,13 @@
static void cleanup_device_parent(struct device *dev)
{
- struct device *d;
- int other = 0;
+ struct kobject *glue_dir = dev->kobj.parent;
- if (!dev->class)
+ /* see if we live in a "glue" directory */
+ if (!dev->class || glue_dir->kset != &dev->class->class_dirs)
return;
- /* see if we live in a parent class directory */
- if (dev->kobj.parent->kset != &dev->class->class_dirs)
- return;
-
- /* if we are the last child of our class, delete the directory */
- down(&dev->class->sem);
- list_for_each_entry(d, &dev->class->devices, node) {
- if (d == dev)
- continue;
- if (d->kobj.parent == dev->kobj.parent) {
- other = 1;
- break;
- }
- }
- if (!other)
- kobject_del(dev->kobj.parent);
- kobject_put(dev->kobj.parent);
- up(&dev->class->sem);
+ kobject_put(glue_dir);
}
#endif