1 files changed, 455 insertions, 279 deletions

diff --git a/lib/kobject.c b/lib/kobject.c
index 3590f022a609..1d63ead1815e 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 +123,286 @@ 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);
 }
 
-/**
- *      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;
+        kref_init(&kobj->kref);
+        INIT_LIST_HEAD(&kobj->entry);
+        kobj->ktype = ktype;
+        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 (%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 +441,6 @@ 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 +459,10 @@ 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 +510,74 @@ 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 +586,130 @@ 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 kset 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 +717,42 @@ 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 +761,94 @@ 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);