driver core: fix namespace issue with devices assigned to classes

  - uses a kset in "struct class" to keep track of all directories
    belonging to this class
  - merges with the /sys/devices/virtual logic.
  - removes the namespace-dir if the last member of that class
    leaves the directory.

There may be locking or refcounting fixes left, I stopped when it seemed
to work with network and sound modules. :)

From: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index b850e0310538..d37cd7f10e3d 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -89,6 +89,8 @@ extern void kobject_unregister(struct kobject *);
 extern struct kobject * kobject_get(struct kobject *);
 extern void kobject_put(struct kobject *);
 
+extern struct kobject *kobject_kset_add_dir(struct kset *kset,
+                                            struct kobject *, const char *);
 extern struct kobject *kobject_add_dir(struct kobject *, const char *);
 
 extern char * kobject_get_path(struct kobject *, gfp_t);