3 files changed, 60 insertions, 9 deletions

diff --git a/lib/kobject.c b/lib/kobject.c
index efe67fa96a71..25204a41a9b0 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -194,6 +194,17 @@ int kobject_add(struct kobject * kobj)
                 unlink(kobj);
                 if (parent)
                         kobject_put(parent);
+
+                /* be noisy on error issues */
+                if (error == -EEXIST)
+                        printk("kobject_add failed for %s with -EEXIST, "
+                               "don't try to register things with the "
+                               "same name in the same directory.\n",
+                               kobject_name(kobj));
+                else
+                        printk("kobject_add failed for %s (%d)\n",
+                               kobject_name(kobj), error);
+                dump_stack();
         }
 
         return error;
@@ -207,18 +218,13 @@ int kobject_add(struct kobject * kobj)
 
 int kobject_register(struct kobject * kobj)
 {
-        int error = 0;
+        int error = -EINVAL;
         if (kobj) {
                 kobject_init(kobj);
                 error = kobject_add(kobj);
-                if (error) {
-                        printk("kobject_register failed for %s (%d)\n",
-                               kobject_name(kobj),error);
-                        dump_stack();
-                } else
+                if (!error)
                         kobject_uevent(kobj, KOBJ_ADD);
-        } else
-                error = -EINVAL;
+        }
         return error;
 }
 
@@ -379,6 +385,44 @@ void kobject_put(struct kobject * kobj)
 }
 
 
+static void dir_release(struct kobject *kobj)
+{
+        kfree(kobj);
+}
+
+static struct kobj_type dir_ktype = {
+        .release        = dir_release,
+        .sysfs_ops      = NULL,
+        .default_attrs  = NULL,
+};
+
+/**
+ *      kobject_add_dir - add sub directory of object.
+ *      @parent:        object in which a directory is created.
+ *      @name:  directory name.
+ *
+ *      Add a plain directory object as child of given object.
+ */
+struct kobject *kobject_add_dir(struct kobject *parent, const char *name)
+{
+        struct kobject *k;
+
+        if (!parent)
+                return NULL;
+
+        k = kzalloc(sizeof(*k), GFP_KERNEL);
+        if (!k)
+                return NULL;
+
+        k->parent = parent;
+        k->ktype = &dir_ktype;
+        kobject_set_name(k, name);
+        kobject_register(k);
+
+        return k;
+}
+EXPORT_SYMBOL_GPL(kobject_add_dir);
+
 /**
  *      kset_init - initialize a kset for use
  *      @k:     kset 
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 086a0c6e888e..982226daf939 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -26,6 +26,8 @@
 #define NUM_ENVP        32      /* number of env pointers */
 
 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
+u64 uevent_seqnum;
+char uevent_helper[UEVENT_HELPER_PATH_LEN] = "/sbin/hotplug";
 static DEFINE_SPINLOCK(sequence_lock);
 static struct sock *uevent_sock;
 
diff --git a/lib/kref.c b/lib/kref.c
index 0d07cc31c818..4a467faf1367 100644
--- a/lib/kref.c
+++ b/lib/kref.c
@@ -52,7 +52,12 @@ int kref_put(struct kref *kref, void (*release)(struct kref *kref))
         WARN_ON(release == NULL);
         WARN_ON(release == (void (*)(struct kref *))kfree);
 
-        if (atomic_dec_and_test(&kref->refcount)) {
+        /*
+         * if current count is one, we are the last user and can release object
+         * right now, avoiding an atomic operation on 'refcount'
+         */
+        if ((atomic_read(&kref->refcount) == 1) ||
+            (atomic_dec_and_test(&kref->refcount))) {
                 release(kref);
                 return 1;
         }