2.6.25-rc7

 lib

diff --git a/lib/kobject.c b/lib/kobject.c
index 3590f02..0d03252 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -18,58 +18,57 @@
 #include <linux/stat.h>
 #include <linux/slab.h>
 
-/**
- *   populate_dir - populate directory with attributes.
- *   @kobj:   object we're working on.
- *
- *   Most subsystems have a set of default attributes that 
- *   are associated with an object that registers with them.
- *   This is a helper called during object registration that 
- *   loops through the default attributes of the subsystem 
- *   and creates attributes files for them in sysfs.
+/*
+ * populate_dir - populate directory with attributes.
+ * @kobj: object we're working on.
  *
+ * Most subsystems have a set of default attributes that are associated
+ * with an object that registers with them.  This is a helper called during
+ * object registration that loops through the default attributes of the
+ * subsystem and creates attributes files for them in sysfs.
  */
-
-static int populate_dir(struct kobject * kobj)
+static int populate_dir(struct kobject *kobj)
 {
-   struct kobj_type * t = get_ktype(kobj);
-   struct attribute * attr;
+   struct kobj_type *t = get_ktype(kobj);
+   struct attribute *attr;
    int error = 0;
    int i;
-   
+
    if (t && t->default_attrs) {
       for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) {
-         if ((error = sysfs_create_file(kobj,attr)))
+         error = sysfs_create_file(kobj, attr);
+         if (error)
             break;
       }
    }
    return error;
 }
 
-static int create_dir(struct kobject * kobj)
+static int create_dir(struct kobject *kobj)
 {
    int error = 0;
    if (kobject_name(kobj)) {
       error = sysfs_create_dir(kobj);
       if (!error) {
-         if ((error = populate_dir(kobj)))
+         error = populate_dir(kobj);
+         if (error)
             sysfs_remove_dir(kobj);
       }
    }
    return error;
 }
 
-static inline struct kobject * to_kobj(struct list_head * entry)
+static inline struct kobject *to_kobj(struct list_head *entry)
 {
-   return container_of(entry,struct kobject,entry);
+   return container_of(entry, struct kobject, entry);
 }
 
 static int get_kobj_path_length(struct kobject *kobj)
 {
    int length = 1;
-   struct kobject * parent = kobj;
+   struct kobject *parent = kobj;
 
-   /* walk up the ancestors until we hit the one pointing to the 
+   /* walk up the ancestors until we hit the one pointing to the
     * root.
     * Add 1 to strlen for leading '/' of each level.
     */
@@ -84,18 +83,19 @@ static int get_kobj_path_length(struct kobject *kobj)
 
 static void fill_kobj_path(struct kobject *kobj, char *path, int length)
 {
-   struct kobject * parent;
+   struct kobject *parent;
 
    --length;
    for (parent = kobj; parent; parent = parent->parent) {
       int cur = strlen(kobject_name(parent));
       /* back up enough to print this name with '/' */
       length -= cur;
-      strncpy (path + length, kobject_name(parent), cur);
+      strncpy(path + length, kobject_name(parent), cur);
       *(path + --length) = '/';
    }
 
-   pr_debug("%s: path = '%s'\n",__FUNCTION__,path);
+   pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
+       kobj, __FUNCTION__, path);
 }
 
 /**
@@ -123,179 +123,285 @@ char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL_GPL(kobject_get_path);
 
-/**
- *   kobject_init - initialize object.
- *   @kobj:   object in question.
- */
-void kobject_init(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);
-   kobj->kset = kset_get(kobj->kset);
+
+   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() 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)
 {
-   if (kobj->kset) {
-      spin_lock(&kobj->kset->list_lock);
-      list_del_init(&kobj->entry);
-      spin_unlock(&kobj->kset->list_lock);
-   }
-   kobject_put(kobj);
+   if (!kobj)
+      return;
+   kref_init(&kobj->kref);
+   INIT_LIST_HEAD(&kobj->entry);
+   kobj->state_in_sysfs = 0;
+   kobj->state_add_uevent_sent = 0;
+   kobj->state_remove_uevent_sent = 0;
+   kobj->state_initialized = 1;
 }
 
-/**
- *   kobject_add - add an object to the hierarchy.
- *   @kobj:   object.
- */
 
-int kobject_add(struct kobject * kobj)
+static int kobject_add_internal(struct kobject *kobj)
 {
    int error = 0;
-   struct kobject * parent;
+   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 attempted to be registered with no name!\n");
+
+   if (!kobj->name || !kobj->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: registering. parent: %s, set: %s\n",
-       kobject_name(kobj), 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) {
-      spin_lock(&kobj->kset->list_lock);
-
       if (!parent)
          parent = kobject_get(&kobj->kset->kobj);
-
-      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)
-         printk(KERN_ERR "kobject_add failed for %s with "
+         printk(KERN_ERR "%s failed for %s with "
                 "-EEXIST, don't try to register things with "
                 "the same name in the same directory.\n",
-                kobject_name(kobj));
+                __FUNCTION__, kobject_name(kobj));
       else
-         printk(KERN_ERR "kobject_add failed for %s (%d)\n",
-                kobject_name(kobj), error);
+         printk(KERN_ERR "%s failed for %s (%d)\n",
+                __FUNCTION__, kobject_name(kobj), error);
       dump_stack();
-   }
+   } else
+      kobj->state_in_sysfs = 1;
 
    return error;
 }
 
 /**
- *   kobject_register - initialize and add an object.
- *   @kobj:   object in question.
+ * kobject_set_name_vargs - Set the name of an kobject
+ * @kobj: struct kobject to set the name of
+ * @fmt: format string used to build the name
+ * @vargs: vargs to format the string.
  */
-
-int kobject_register(struct kobject * kobj)
+static int kobject_set_name_vargs(struct kobject *kobj, const char *fmt,
+              va_list vargs)
 {
-   int error = -EINVAL;
-   if (kobj) {
-      kobject_init(kobj);
-      error = kobject_add(kobj);
-      if (!error)
-         kobject_uevent(kobj, KOBJ_ADD);
-   }
-   return error;
-}
+   va_list aq;
+   char *name;
+
+   va_copy(aq, vargs);
+   name = kvasprintf(GFP_KERNEL, fmt, vargs);
+   va_end(aq);
+
+   if (!name)
+      return -ENOMEM;
+
+   /* Free the old name, if necessary. */
+   kfree(kobj->name);
+
+   /* Now, set the new name */
+   kobj->name = name;
 
+   return 0;
+}
 
 /**
  * kobject_set_name - Set the name of a kobject
- * @kobj: kobject to name
+ * @kobj: struct kobject to set the name of
  * @fmt: format string used to build the name
  *
  * This sets the name of the kobject.  If you have already added the
  * kobject to the system, you must call kobject_rename() in order to
  * change the name of the kobject.
  */
-int kobject_set_name(struct kobject * kobj, const char * fmt, ...)
+int kobject_set_name(struct kobject *kobj, const char *fmt, ...)
 {
-   int error = 0;
-   int limit;
-   int need;
    va_list args;
-   char *name;
+   int retval;
 
-   /* find out how big a buffer we need */
-   name = kmalloc(1024, GFP_KERNEL);
-   if (!name) {
-      error = -ENOMEM;
-      goto done;
-   }
    va_start(args, fmt);
-   need = vsnprintf(name, 1024, fmt, args);
+   retval = kobject_set_name_vargs(kobj, fmt, args);
    va_end(args);
-   kfree(name);
 
-   /* Allocate the new space and copy the string in */
-   limit = need + 1;
-   name = kmalloc(limit, GFP_KERNEL);
-   if (!name) {
-      error = -ENOMEM;
-      goto done;
+   return retval;
+}
+EXPORT_SYMBOL(kobject_set_name);
+
+/**
+ * kobject_init - initialize a kobject structure
+ * @kobj: pointer to the kobject to initialize
+ * @ktype: pointer to the ktype for this kobject.
+ *
+ * This function will properly initialize a kobject such that it can then
+ * be passed to the kobject_add() call.
+ *
+ * After this function is called, the kobject MUST be cleaned up by a call
+ * to kobject_put(), not by a call to kfree directly to ensure that all of
+ * the memory is cleaned up properly.
+ */
+void kobject_init(struct kobject *kobj, struct kobj_type *ktype)
+{
+   char *err_str;
+
+   if (!kobj) {
+      err_str = "invalid kobject pointer!";
+      goto error;
+   }
+   if (!ktype) {
+      err_str = "must have a ktype to be initialized properly!\n";
+      goto error;
+   }
+   if (kobj->state_initialized) {
+      /* do not error out as sometimes we can recover */
+      printk(KERN_ERR "kobject (%p): tried to init an initialized "
+             "object, something is seriously wrong.\n", kobj);
+      dump_stack();
    }
-   va_start(args, fmt);
-   need = vsnprintf(name, limit, fmt, args);
-   va_end(args);
 
-   /* something wrong with the string we copied? */
-   if (need >= limit) {
-      kfree(name);
-      error = -EFAULT;
-      goto done;
+   kobject_init_internal(kobj);
+   kobj->ktype = ktype;
+   return;
+
+error:
+   printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
+   dump_stack();
+}
+EXPORT_SYMBOL(kobject_init);
+
+static int kobject_add_varg(struct kobject *kobj, struct kobject *parent,
+             const char *fmt, va_list vargs)
+{
+   va_list aq;
+   int retval;
+
+   va_copy(aq, vargs);
+   retval = kobject_set_name_vargs(kobj, fmt, aq);
+   va_end(aq);
+   if (retval) {
+      printk(KERN_ERR "kobject: can not set name properly!\n");
+      return retval;
    }
+   kobj->parent = parent;
+   return kobject_add_internal(kobj);
+}
 
-   /* Free the old name, if necessary. */
-   kfree(kobj->k_name);
+/**
+ * kobject_add - the main kobject add function
+ * @kobj: the kobject to add
+ * @parent: pointer to the parent of the kobject.
+ * @fmt: format to name the kobject with.
+ *
+ * The kobject name is set and added to the kobject hierarchy in this
+ * function.
+ *
+ * If @parent is set, then the parent of the @kobj will be set to it.
+ * If @parent is NULL, then the parent of the @kobj will be set to the
+ * kobject associted with the kset assigned to this kobject.  If no kset
+ * is assigned to the kobject, then the kobject will be located in the
+ * root of the sysfs tree.
+ *
+ * If this function returns an error, kobject_put() must be called to
+ * properly clean up the memory associated with the object.
+ * 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 "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.
+ */
+int kobject_add(struct kobject *kobj, struct kobject *parent,
+      const char *fmt, ...)
+{
+   va_list args;
+   int retval;
 
-   /* Now, set the new name */
-   kobj->k_name = name;
-done:
-   return error;
+   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);
+
+   return retval;
 }
-EXPORT_SYMBOL(kobject_set_name);
+EXPORT_SYMBOL(kobject_add);
 
 /**
- *   kobject_rename - change the name of an object
- *   @kobj:   object in question.
- *   @new_name: object's new name
+ * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy
+ * @kobj: pointer to the kobject to initialize
+ * @ktype: pointer to the ktype for this kobject.
+ * @parent: pointer to the parent of this kobject.
+ * @fmt: the name of the kobject.
+ *
+ * This function combines the call to kobject_init() and
+ * kobject_add().  The same type of error handling after a call to
+ * kobject_add() and kobject lifetime rules are the same here.
  */
+int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype,
+          struct kobject *parent, const char *fmt, ...)
+{
+   va_list args;
+   int retval;
+
+   kobject_init(kobj, ktype);
+
+   va_start(args, fmt);
+   retval = kobject_add_varg(kobj, parent, fmt, args);
+   va_end(args);
+
+   return retval;
+}
+EXPORT_SYMBOL_GPL(kobject_init_and_add);
 
-int kobject_rename(struct kobject * kobj, const char *new_name)
+/**
+ * kobject_rename - change the name of an object
+ * @kobj: object in question.
+ * @new_name: object's new name
+ */
+int kobject_rename(struct kobject *kobj, const char *new_name)
 {
    int error = 0;
    const char *devpath = NULL;
@@ -334,8 +440,6 @@ int kobject_rename(struct kobject * kobj, const char *new_name)
    sprintf(devpath_string, "DEVPATH_OLD=%s", devpath);
    envp[0] = devpath_string;
    envp[1] = NULL;
-   /* Note : if we want to send the new name alone, not the full path,
-    * we could probably use kobject_name(kobj); */
 
    error = sysfs_rename_dir(kobj, new_name);
 
@@ -354,11 +458,10 @@ out:
 }
 
 /**
- *   kobject_move - move object to another parent
- *   @kobj:   object in question.
- *   @new_parent: object's new parent (can be NULL)
+ * kobject_move - move object to another parent
+ * @kobj: object in question.
+ * @new_parent: object's new parent (can be NULL)
  */
-
 int kobject_move(struct kobject *kobj, struct kobject *new_parent)
 {
    int error;
@@ -406,68 +509,74 @@ out:
 }
 
 /**
- *   kobject_del - unlink kobject from hierarchy.
- *    @kobj:   object.
+ * kobject_del - unlink kobject from hierarchy.
+ * @kobj: object.
  */
-
-void kobject_del(struct kobject * kobj)
+void kobject_del(struct kobject *kobj)
 {
    if (!kobj)
       return;
-   sysfs_remove_dir(kobj);
-   unlink(kobj);
-}
 
-/**
- *   kobject_unregister - remove object from hierarchy and decrement refcount.
- *   @kobj:   object going away.
- */
-
-void kobject_unregister(struct kobject * kobj)
-{
-   if (!kobj)
-      return;
-   pr_debug("kobject %s: unregistering\n",kobject_name(kobj));
-   kobject_uevent(kobj, KOBJ_REMOVE);
-   kobject_del(kobj);
-   kobject_put(kobj);
+   sysfs_remove_dir(kobj);
+   kobj->state_in_sysfs = 0;
+   kobj_kset_leave(kobj);
+   kobject_put(kobj->parent);
+   kobj->parent = NULL;
 }
 
 /**
- *   kobject_get - increment refcount for object.
- *   @kobj:   object.
+ * kobject_get - increment refcount for object.
+ * @kobj: object.
  */
-
-struct kobject * kobject_get(struct kobject * kobj)
+struct kobject *kobject_get(struct kobject *kobj)
 {
    if (kobj)
       kref_get(&kobj->kref);
    return kobj;
 }
 
-/**
- *   kobject_cleanup - free kobject resources. 
- *   @kobj:   object.
+/*
+ * kobject_cleanup - free kobject resources.
+ * @kobj: object to cleanup
  */
-
-void kobject_cleanup(struct kobject * kobj)
+static void kobject_cleanup(struct kobject *kobj)
 {
-   struct kobj_type * t = get_ktype(kobj);
-   struct kset * s = kobj->kset;
-   struct kobject * parent = kobj->parent;
-   const char *name = kobj->k_name;
+   struct kobj_type *t = get_ktype(kobj);
+   const char *name = kobj->name;
+
+   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);
+   }
 
-   pr_debug("kobject %s: cleaning up\n",kobject_name(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) {
+      pr_debug("kobject: '%s': free name\n", name);
       kfree(name);
    }
-   if (s)
-      kset_put(s);
-   kobject_put(parent);
 }
 
 static void kobject_release(struct kref *kref)
@@ -476,107 +585,130 @@ static void kobject_release(struct kref *kref)
 }
 
 /**
- *   kobject_put - decrement refcount for object.
- *   @kobj:   object.
+ * kobject_put - decrement refcount for object.
+ * @kobj: object.
  *
- *   Decrement the refcount, and if 0, call kobject_cleanup().
+ * Decrement the refcount, and if 0, call kobject_cleanup().
  */
-void kobject_put(struct kobject * kobj)
+void kobject_put(struct kobject *kobj)
 {
    if (kobj)
       kref_put(&kobj->kref, kobject_release);
 }
 
-
-static void dir_release(struct kobject *kobj)
+static void dynamic_kobj_release(struct kobject *kobj)
 {
+   pr_debug("kobject: (%p): %s\n", kobj, __FUNCTION__);
    kfree(kobj);
 }
 
-static struct kobj_type dir_ktype = {
-   .release   = dir_release,
-   .sysfs_ops   = NULL,
-   .default_attrs   = NULL,
+static struct kobj_type dynamic_kobj_ktype = {
+   .release   = dynamic_kobj_release,
+   .sysfs_ops   = &kobj_sysfs_ops,
 };
 
 /**
- *   kobject_kset_add_dir - add sub directory of object.
- *   @kset:      kset the directory is belongs to.
- *   @parent:   object in which a directory is created.
- *   @name:   directory name.
+ * kobject_create - create a struct kobject dynamically
  *
- *   Add a plain directory object as child of given object.
+ * This function creates a kobject structure dynamically and sets it up
+ * to be a "dynamic" kobject with a default release function set up.
+ *
+ * If the kobject was not able to be created, NULL will be returned.
+ * The kobject structure returned from here must be cleaned up with a
+ * call to kobject_put() and not kfree(), as kobject_init() has
+ * already been called on this structure.
  */
-struct kobject *kobject_kset_add_dir(struct kset *kset,
-                 struct kobject *parent, const char *name)
+struct kobject *kobject_create(void)
 {
-   struct kobject *k;
-   int ret;
-
-   if (!parent)
-      return NULL;
-
-   k = kzalloc(sizeof(*k), GFP_KERNEL);
-   if (!k)
-      return NULL;
+   struct kobject *kobj;
 
-   k->kset = kset;
-   k->parent = parent;
-   k->ktype = &dir_ktype;
-   kobject_set_name(k, name);
-   ret = kobject_register(k);
-   if (ret < 0) {
-      printk(KERN_WARNING "%s: kobject_register error: %d\n",
-         __func__, ret);
-      kobject_del(k);
+   kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
+   if (!kobj)
       return NULL;
-   }
 
-   return k;
+   kobject_init(kobj, &dynamic_kobj_ktype);
+   return kobj;
 }
 
 /**
- *   kobject_add_dir - add sub directory of object.
- *   @parent:   object in which a directory is created.
- *   @name:   directory name.
+ * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs
+ *
+ * @name: the name for the kset
+ * @parent: the parent kobject of this kobject, if any.
+ *
+ * This function creates a kobject structure dynamically and registers it
+ * with sysfs.  When you are finished with this structure, call
+ * kobject_put() and the structure will be dynamically freed when
+ * it is no longer being used.
  *
- *   Add a plain directory object as child of given object.
+ * If the kobject was not able to be created, NULL will be returned.
  */
-struct kobject *kobject_add_dir(struct kobject *parent, const char *name)
+struct kobject *kobject_create_and_add(const char *name, struct kobject *parent)
 {
-   return kobject_kset_add_dir(NULL, parent, name);
+   struct kobject *kobj;
+   int retval;
+
+   kobj = kobject_create();
+   if (!kobj)
+      return NULL;
+
+   retval = kobject_add(kobj, parent, "%s", name);
+   if (retval) {
+      printk(KERN_WARNING "%s: kobject_add error: %d\n",
+             __FUNCTION__, retval);
+      kobject_put(kobj);
+      kobj = NULL;
+   }
+   return kobj;
 }
+EXPORT_SYMBOL_GPL(kobject_create_and_add);
 
 /**
- *   kset_init - initialize a kset for use
- *   @k:   kset 
+ * kset_init - initialize a kset for use
+ * @k: kset
  */
-
-void kset_init(struct kset * k)
+void kset_init(struct kset *k)
 {
-   kobject_init(&k->kobj);
+   kobject_init_internal(&k->kobj);
    INIT_LIST_HEAD(&k->list);
    spin_lock_init(&k->list_lock);
 }
 
+/* default kobject attribute operations */
+static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr,
+               char *buf)
+{
+   struct kobj_attribute *kattr;
+   ssize_t ret = -EIO;
 
-/**
- *   kset_add - add a kset object to the hierarchy.
- *   @k:   kset.
- */
+   kattr = container_of(attr, struct kobj_attribute, attr);
+   if (kattr->show)
+      ret = kattr->show(kobj, kattr, buf);
+   return ret;
+}
 
-int kset_add(struct kset * k)
+static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr,
+                const char *buf, size_t count)
 {
-   return kobject_add(&k->kobj);
+   struct kobj_attribute *kattr;
+   ssize_t ret = -EIO;
+
+   kattr = container_of(attr, struct kobj_attribute, attr);
+   if (kattr->store)
+      ret = kattr->store(kobj, kattr, buf, count);
+   return ret;
 }
 
+struct sysfs_ops kobj_sysfs_ops = {
+   .show   = kobj_attr_show,
+   .store   = kobj_attr_store,
+};
 
 /**
- *   kset_register - initialize and add a kset.
- *   @k:   kset.
+ * kset_register - initialize and add a kset.
+ * @k: kset.
  */
-
-int kset_register(struct kset * k)
+int kset_register(struct kset *k)
 {
    int err;
 
@@ -584,46 +716,42 @@ int kset_register(struct kset * k)
       return -EINVAL;
 
    kset_init(k);
-   err = kset_add(k);
+   err = kobject_add_internal(&k->kobj);
    if (err)
       return err;
    kobject_uevent(&k->kobj, KOBJ_ADD);
    return 0;
 }
 
-
 /**
- *   kset_unregister - remove a kset.
- *   @k:   kset.
+ * kset_unregister - remove a kset.
+ * @k: kset.
  */
-
-void kset_unregister(struct kset * k)
+void kset_unregister(struct kset *k)
 {
    if (!k)
       return;
-   kobject_unregister(&k->kobj);
+   kobject_put(&k->kobj);
 }
 
-
 /**
- *   kset_find_obj - search for object in kset.
- *   @kset:   kset we're looking in.
- *   @name:   object's name.
+ * kset_find_obj - search for object in kset.
+ * @kset: kset we're looking in.
+ * @name: object's name.
  *
- *   Lock kset via @kset->subsys, and iterate over @kset->list,
- *   looking for a matching kobject. If matching object is found
- *   take a reference and return the object.
+ * Lock kset via @kset->subsys, and iterate over @kset->list,
+ * looking for a matching kobject. If matching object is found
+ * take a reference and return the object.
  */
-
-struct kobject * kset_find_obj(struct kset * kset, const char * name)
+struct kobject *kset_find_obj(struct kset *kset, const char *name)
 {
-   struct list_head * entry;
-   struct kobject * ret = NULL;
+   struct list_head *entry;
+   struct kobject *ret = NULL;
 
    spin_lock(&kset->list_lock);
-   list_for_each(entry,&kset->list) {
-      struct kobject * k = to_kobj(entry);
-      if (kobject_name(k) && !strcmp(kobject_name(k),name)) {
+   list_for_each(entry, &kset->list) {
+      struct kobject *k = to_kobj(entry);
+      if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
          ret = kobject_get(k);
          break;
       }
@@ -632,47 +760,94 @@ struct kobject * kset_find_obj(struct kset * kset, const char * name)
    return ret;
 }
 
-int subsystem_register(struct kset *s)
+static void kset_release(struct kobject *kobj)
 {
-   return kset_register(s);
+   struct kset *kset = container_of(kobj, struct kset, kobj);
+   pr_debug("kobject: '%s' (%p): %s\n",
+       kobject_name(kobj), kobj, __FUNCTION__);
+   kfree(kset);
 }
 
-void subsystem_unregister(struct kset *s)
+static struct kobj_type kset_ktype = {
+   .sysfs_ops   = &kobj_sysfs_ops,
+   .release = kset_release,
+};
+
+/**
+ * kset_create - create a struct kset dynamically
+ *
+ * @name: the name for the kset
+ * @uevent_ops: a struct kset_uevent_ops for the kset
+ * @parent_kobj: the parent kobject of this kset, if any.
+ *
+ * This function creates a kset structure dynamically.  This structure can
+ * then be registered with the system and show up in sysfs with a call to
+ * kset_register().  When you are finished with this structure, if
+ * kset_register() has been called, call kset_unregister() and the
+ * structure will be dynamically freed when it is no longer being used.
+ *
+ * If the kset was not able to be created, NULL will be returned.
+ */
+static struct kset *kset_create(const char *name,
+            struct kset_uevent_ops *uevent_ops,
+            struct kobject *parent_kobj)
 {
-   kset_unregister(s);
+   struct kset *kset;
+
+   kset = kzalloc(sizeof(*kset), GFP_KERNEL);
+   if (!kset)
+      return NULL;
+   kobject_set_name(&kset->kobj, name);
+   kset->uevent_ops = uevent_ops;
+   kset->kobj.parent = parent_kobj;
+
+   /*
+    * The kobject of this kset will have a type of kset_ktype and belong to
+    * no kset itself.  That way we can properly free it when it is
+    * finished being used.
+    */
+   kset->kobj.ktype = &kset_ktype;
+   kset->kobj.kset = NULL;
+
+   return kset;
 }
 
 /**
- *   subsystem_create_file - export sysfs attribute file.
- *   @s:   subsystem.
- *   @a:   subsystem attribute descriptor.
+ * kset_create_and_add - create a struct kset dynamically and add it to sysfs
+ *
+ * @name: the name for the kset
+ * @uevent_ops: a struct kset_uevent_ops for the kset
+ * @parent_kobj: the parent kobject of this kset, if any.
+ *
+ * This function creates a kset structure dynamically and registers it
+ * with sysfs.  When you are finished with this structure, call
+ * kset_unregister() and the structure will be dynamically freed when it
+ * is no longer being used.
+ *
+ * If the kset was not able to be created, NULL will be returned.
  */
-
-int subsys_create_file(struct kset *s, struct subsys_attribute *a)
+struct kset *kset_create_and_add(const char *name,
+             struct kset_uevent_ops *uevent_ops,
+             struct kobject *parent_kobj)
 {
-   int error = 0;
-
-   if (!s || !a)
-      return -EINVAL;
+   struct kset *kset;
+   int error;
 
-   if (kset_get(s)) {
-      error = sysfs_create_file(&s->kobj, &a->attr);
-      kset_put(s);
+   kset = kset_create(name, uevent_ops, parent_kobj);
+   if (!kset)
+      return NULL;
+   error = kset_register(kset);
+   if (error) {
+      kfree(kset);
+      return NULL;
    }
-   return error;
+   return kset;
 }
+EXPORT_SYMBOL_GPL(kset_create_and_add);
 
-EXPORT_SYMBOL(kobject_init);
-EXPORT_SYMBOL(kobject_register);
-EXPORT_SYMBOL(kobject_unregister);
 EXPORT_SYMBOL(kobject_get);
 EXPORT_SYMBOL(kobject_put);
-EXPORT_SYMBOL(kobject_add);
 EXPORT_SYMBOL(kobject_del);
 
 EXPORT_SYMBOL(kset_register);
 EXPORT_SYMBOL(kset_unregister);
-
-EXPORT_SYMBOL(subsystem_register);
-EXPORT_SYMBOL(subsystem_unregister);
-EXPORT_SYMBOL(subsys_create_file);