Merge branch 'cgroup/for-3.7-fixes' into cgroup/for-3.8

This is to receive device_cgroup fixes so that further device_cgroup
changes can be made in cgroup/for-3.8.

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 17 insertions, 1 deletions

diff --git a/fs/char_dev.c b/fs/char_dev.c
index 3f152b92a94a..afc2bb691780 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -471,9 +471,19 @@ static int exact_lock(dev_t dev, void *data)
  */
 int cdev_add(struct cdev *p, dev_t dev, unsigned count)
 {
+        int error;
+
         p->dev = dev;
         p->count = count;
-        return kobj_map(cdev_map, dev, count, NULL, exact_match, exact_lock, p);
+
+        error = kobj_map(cdev_map, dev, count, NULL,
+                         exact_match, exact_lock, p);
+        if (error)
+                return error;
+
+        kobject_get(p->kobj.parent);
+
+        return 0;
 }
 
 static void cdev_unmap(dev_t dev, unsigned count)
@@ -498,14 +508,20 @@ void cdev_del(struct cdev *p)
 static void cdev_default_release(struct kobject *kobj)
 {
         struct cdev *p = container_of(kobj, struct cdev, kobj);
+        struct kobject *parent = kobj->parent;
+
         cdev_purge(p);
+        kobject_put(parent);
 }
 
 static void cdev_dynamic_release(struct kobject *kobj)
 {
         struct cdev *p = container_of(kobj, struct cdev, kobj);
+        struct kobject *parent = kobj->parent;
+
         cdev_purge(p);
         kfree(p);
+        kobject_put(parent);
 }
 
 static struct kobj_type ktype_cdev_default = {