4 files changed, 119 insertions, 99 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 675a719dcdd2..d5d542db96fd 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -576,8 +576,8 @@ static struct kobject *get_device_parent(struct device *dev,
 
                 /*
                  * 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 @@ static struct kobject *get_device_parent(struct device *dev,
                         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 struct kobject *get_device_parent(struct device *dev,
 
 static void cleanup_device_parent(struct device *dev)
 {
-        struct device *d;
-        int other = 0;
+        struct kobject *glue_dir = dev->kobj.parent;
 
-        if (!dev->class)
-                return;
-
-        /* see if we live in a parent class directory */
-        if (dev->kobj.parent->kset != &dev->class->class_dirs)
+        /* see if we live in a "glue" directory */
+        if (!dev->class || glue_dir->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
 
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index 63967da073af..be03ce83f9cc 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -68,6 +68,11 @@ struct kobject {
         struct kset             * kset;
         struct kobj_type        * ktype;
         struct sysfs_dirent     * sd;
+        unsigned int state_initialized:1;
+        unsigned int state_name_set:1;
+        unsigned int state_in_sysfs:1;
+        unsigned int state_add_uevent_sent:1;
+        unsigned int state_remove_uevent_sent:1;
 };
 
 extern int kobject_set_name(struct kobject *, const char *, ...)
diff --git a/lib/kobject.c b/lib/kobject.c
index c321f1910cc2..4fce5ca42c2e 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -124,85 +124,74 @@ char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL_GPL(kobject_get_path);
 
-static void kobject_init_internal(struct kobject * kobj)
+/* add the kobject to its kset's list */
+static void kobj_kset_join(struct kobject *kobj)
 {
-        if (!kobj)
+        if (!kobj->kset)
                 return;
-        kref_init(&kobj->kref);
-        INIT_LIST_HEAD(&kobj->entry);
+
+        kset_get(kobj->kset);
+        spin_lock(&kobj->kset->list_lock);
+        list_add_tail(&kobj->entry, &kobj->kset->list);
+        spin_unlock(&kobj->kset->list_lock);
 }
 
+/* remove the kobject from its kset's list */
+static void kobj_kset_leave(struct kobject *kobj)
+{
+        if (!kobj->kset)
+                return;
 
-/**
- *      unlink - remove kobject from kset list.
- *      @kobj:  kobject.
- *
- *      Remove the kobject from the kset list and decrement
- *      its parent's refcount.
- *      This is separated out, so we can use it in both 
- *      kobject_del() and kobject_add_internal() on error.
- */
+        spin_lock(&kobj->kset->list_lock);
+        list_del_init(&kobj->entry);
+        spin_unlock(&kobj->kset->list_lock);
+        kset_put(kobj->kset);
+}
 
-static void unlink(struct kobject * kobj)
+static void kobject_init_internal(struct kobject * kobj)
 {
-        struct kobject *parent = kobj->parent;
-
-        if (kobj->kset) {
-                spin_lock(&kobj->kset->list_lock);
-                list_del_init(&kobj->entry);
-                spin_unlock(&kobj->kset->list_lock);
-        }
-        kobj->parent = NULL;
-        kobject_put(kobj);
-        kobject_put(parent);
+        if (!kobj)
+                return;
+        kref_init(&kobj->kref);
+        INIT_LIST_HEAD(&kobj->entry);
 }
 
+
 static int kobject_add_internal(struct kobject *kobj)
 {
         int error = 0;
         struct kobject * parent;
 
-        if (!(kobj = kobject_get(kobj)))
+        if (!kobj)
                 return -ENOENT;
-        if (!kobj->k_name)
-                kobject_set_name(kobj, "NO_NAME");
-        if (!*kobj->k_name) {
-                pr_debug("kobject (%p) attempted to be registered with no "
+
+        if (!kobj->k_name || !kobj->k_name[0]) {
+                pr_debug("kobject: (%p): attempted to be registered with empty "
                          "name!\n", kobj);
                 WARN_ON(1);
-                kobject_put(kobj);
                 return -EINVAL;
         }
-        parent = kobject_get(kobj->parent);
 
-        pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
-                 kobject_name(kobj), kobj, __FUNCTION__,
-                 parent ? kobject_name(parent) : "<NULL>",
-                 kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>" );
+        parent = kobject_get(kobj->parent);
 
+        /* join kset if set, use it as parent if we do not already have one */
         if (kobj->kset) {
-                kobj->kset = kset_get(kobj->kset);
-
-                if (!parent) {
+                if (!parent)
                         parent = kobject_get(&kobj->kset->kobj);
-                        /*
-                         * If the kset is our parent, get a second
-                         * reference, we drop both the kset and the
-                         * parent ref on cleanup
-                         */
-                        kobject_get(parent);
-                }
-
-                spin_lock(&kobj->kset->list_lock);
-                list_add_tail(&kobj->entry, &kobj->kset->list);
-                spin_unlock(&kobj->kset->list_lock);
+                kobj_kset_join(kobj);
                 kobj->parent = parent;
         }
 
+        pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n",
+                 kobject_name(kobj), kobj, __FUNCTION__,
+                 parent ? kobject_name(parent) : "<NULL>",
+                 kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>" );
+
         error = create_dir(kobj);
         if (error) {
-                /* unlink does the kobject_put() for us */
-                unlink(kobj);
+                kobj_kset_leave(kobj);
+                kobject_put(parent);
+                kobj->parent = NULL;
 
                 /* be noisy on error issues */
                 if (error == -EEXIST)
@@ -214,7 +203,8 @@ static int kobject_add_internal(struct kobject *kobj)
                         printk(KERN_ERR "%s failed for %s (%d)\n",
                                __FUNCTION__, kobject_name(kobj), error);
                 dump_stack();
-        }
+        } else
+                kobj->state_in_sysfs = 1;
 
         return error;
 }
@@ -238,11 +228,13 @@ static int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
         if (!name)
                 return -ENOMEM;
 
+
         /* Free the old name, if necessary. */
         kfree(kobj->k_name);
 
         /* Now, set the new name */
         kobj->k_name = name;
+        kobj->state_name_set = 1;
 
         return 0;
 }
@@ -293,20 +285,25 @@ void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
                 err_str = "must have a ktype to be initialized properly!\n";
                 goto error;
         }
-        if (atomic_read(&kobj->kref.refcount)) {
+        if (kobj->state_initialized) {
                 /* do not error out as sometimes we can recover */
-                printk(KERN_ERR "kobject: reference count is already set, "
-                       "something is seriously wrong.\n");
+                printk(KERN_ERR "kobject (%p): tried to init an initialized "
+                       "object, something is seriously wrong.\n", kobj);
                 dump_stack();
         }
 
         kref_init(&kobj->kref);
         INIT_LIST_HEAD(&kobj->entry);
         kobj->ktype = ktype;
+        kobj->state_name_set = 0;
+        kobj->state_in_sysfs = 0;
+        kobj->state_add_uevent_sent = 0;
+        kobj->state_remove_uevent_sent = 0;
+        kobj->state_initialized = 1;
         return;
 
 error:
-        printk(KERN_ERR "kobject: %s\n", err_str);
+        printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
         dump_stack();
 }
 EXPORT_SYMBOL(kobject_init);
@@ -345,17 +342,10 @@ static int kobject_add_varg(struct kobject *kobj, struct kobject *parent,
  *
  * If this function returns an error, kobject_put() must be called to
  * properly clean up the memory associated with the object.
- *
- * If the function is successful, the only way to properly clean up the
- * memory is with a call to kobject_del(), in which case, a call to
- * kobject_put() is not necessary (kobject_del() does the final
- * kobject_put() to call the release function in the ktype's release
- * pointer.)
- *
  * Under no instance should the kobject that is passed to this function
  * be directly freed with a call to kfree(), that can leak memory.
  *
- * Note, no uevent will be created with this call, the caller should set
+ * Note, no "add" uevent will be created with this call, the caller should set
  * up all of the necessary sysfs files for the object and then call
  * kobject_uevent() with the UEVENT_ADD parameter to ensure that
  * userspace is properly notified of this kobject's creation.
@@ -369,6 +359,13 @@ int kobject_add(struct kobject *kobj, struct kobject *parent,
         if (!kobj)
                 return -EINVAL;
 
+        if (!kobj->state_initialized) {
+                printk(KERN_ERR "kobject '%s' (%p): tried to add an "
+                       "uninitialized object, something is seriously wrong.\n",
+                       kobject_name(kobj), kobj);
+                dump_stack();
+                return -EINVAL;
+        }
         va_start(args, fmt);
         retval = kobject_add_varg(kobj, parent, fmt, args);
         va_end(args);
@@ -527,8 +524,12 @@ void kobject_del(struct kobject * kobj)
 {
         if (!kobj)
                 return;
+
         sysfs_remove_dir(kobj);
-        unlink(kobj);
+        kobj->state_in_sysfs = 0;
+        kobj_kset_leave(kobj);
+        kobject_put(kobj->parent);
+        kobj->parent = NULL;
 }
 
 /**
@@ -565,21 +566,43 @@ struct kobject * kobject_get(struct kobject * kobj)
  */
 static void kobject_cleanup(struct kobject *kobj)
 {
-        struct kobj_type * t = get_ktype(kobj);
-        struct kset * s = kobj->kset;
+        struct kobj_type *t = get_ktype(kobj);
         const char *name = kobj->k_name;
+        int name_set = kobj->state_name_set;
 
         pr_debug("kobject: '%s' (%p): %s\n",
                  kobject_name(kobj), kobj, __FUNCTION__);
+
+        if (t && !t->release)
+                pr_debug("kobject: '%s' (%p): does not have a release() "
+                         "function, it is broken and must be fixed.\n",
+                         kobject_name(kobj), kobj);
+
+        /* send "remove" if the caller did not do it but sent "add" */
+        if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) {
+                pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n",
+                         kobject_name(kobj), kobj);
+                kobject_uevent(kobj, KOBJ_REMOVE);
+        }
+
+        /* remove from sysfs if the caller did not do it */
+        if (kobj->state_in_sysfs) {
+                pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n",
+                         kobject_name(kobj), kobj);
+                kobject_del(kobj);
+        }
+
         if (t && t->release) {
+                pr_debug("kobject: '%s' (%p): calling ktype release\n",
+                         kobject_name(kobj), kobj);
                 t->release(kobj);
-                /* If we have a release function, we can guess that this was
-                 * not a statically allocated kobject, so we should be safe to
-                 * free the name */
+        }
+
+        /* free name if we allocated it */
+        if (name_set && name) {
+                pr_debug("kobject: '%s': free name\n", name);
                 kfree(name);
         }
-        if (s)
-                kset_put(s);
 }
 
 static void kobject_release(struct kref *kref)
@@ -601,8 +624,7 @@ void kobject_put(struct kobject * kobj)
 
 static void dynamic_kobj_release(struct kobject *kobj)
 {
-        pr_debug("kobject: '%s' (%p): %s\n",
-                 kobject_name(kobj), kobj, __FUNCTION__);
+        pr_debug("kobject: (%p): %s\n", kobj, __FUNCTION__);
         kfree(kobj);
 }
 
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 51dc4d287add..b021e67c4294 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -180,6 +180,17 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
                 }
         }
 
+        /*
+         * Mark "add" and "remove" events in the object to ensure proper
+         * events to userspace during automatic cleanup. If the object did
+         * send an "add" event, "remove" will automatically generated by
+         * the core, if not already done by the caller.
+         */
+        if (action == KOBJ_ADD)
+                kobj->state_add_uevent_sent = 1;
+        else if (action == KOBJ_REMOVE)
+                kobj->state_remove_uevent_sent = 1;
+
         /* we will send an event, so request a new sequence number */
         spin_lock(&sequence_lock);
         seq = ++uevent_seqnum;