Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

Pull SCSI target updates from Nicholas Bellinger:
 "This series contains HCH's changes to absorb configfs attribute
  ->show() + ->store() function pointer usage from it's original
  tree-wide consumers, into common configfs code.

  It includes usb-gadget, target w/ drivers, netconsole and ocfs2
  changes to realize the improved simplicity, that now renders the
  original include/target/configfs_macros.h CPP magic for fabric drivers
  and others, unnecessary and obsolete.

  And with common code in place, new configfs attributes can be added
  easier than ever before.

  Note, there are further improvements in-flight from other folks for
  v4.5 code in configfs land, plus number of target fixes for post -rc1
  code"

In the meantime, a new user of the now-removed old configfs API came in
through the char/misc tree in commit 7bd1d4093c2f ("stm class: Introduce
an abstraction for System Trace Module devices").

This merge resolution comes from Alexander Shishkin, who updated his stm
class tracing abstraction to account for the removal of the old
show_attribute and store_attribute methods in commit 517982229f78
("configfs: remove old API") from this pull.  As Alexander says about
that patch:

 "There's no need to keep an extra wrapper structure per item and the
  awkward show_attribute/store_attribute item ops are no longer needed.

  This patch converts policy code to the new api, all the while making
  the code quite a bit smaller and easier on the eyes.

  Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>"

That patch was folded into the merge so that the tree should be fully
bisectable.

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (23 commits)
  configfs: remove old API
  ocfs2/cluster: use per-attribute show and store methods
  ocfs2/cluster: move locking into attribute store methods
  netconsole: use per-attribute show and store methods
  target: use per-attribute show and store methods
  spear13xx_pcie_gadget: use per-attribute show and store methods
  dlm: use per-attribute show and store methods
  usb-gadget/f_serial: use per-attribute show and store methods
  usb-gadget/f_phonet: use per-attribute show and store methods
  usb-gadget/f_obex: use per-attribute show and store methods
  usb-gadget/f_uac2: use per-attribute show and store methods
  usb-gadget/f_uac1: use per-attribute show and store methods
  usb-gadget/f_mass_storage: use per-attribute show and store methods
  usb-gadget/f_sourcesink: use per-attribute show and store methods
  usb-gadget/f_printer: use per-attribute show and store methods
  usb-gadget/f_midi: use per-attribute show and store methods
  usb-gadget/f_loopback: use per-attribute show and store methods
  usb-gadget/ether: use per-attribute show and store methods
  usb-gadget/f_acm: use per-attribute show and store methods
  usb-gadget/f_hid: use per-attribute show and store methods
  ...

5 files changed, 11 insertions, 961 deletions

diff --git a/Documentation/filesystems/Makefile b/Documentation/filesystems/Makefile
index 13483d192ebb..883010ce5e35 100644
--- a/Documentation/filesystems/Makefile
+++ b/Documentation/filesystems/Makefile
@@ -1,5 +1,3 @@
-subdir-y := configfs
-
 # List of programs to build
 hostprogs-y := dnotify_test
 
diff --git a/Documentation/filesystems/configfs/Makefile b/Documentation/filesystems/configfs/Makefile
deleted file mode 100644
index be7ec5e67dbc..000000000000
--- a/Documentation/filesystems/configfs/Makefile
+++ /dev/null
@@ -1,3 +0,0 @@
-ifneq ($(CONFIG_CONFIGFS_FS),)
-obj-m += configfs_example_explicit.o configfs_example_macros.o
-endif
diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs/configfs.txt
index b40fec9d3f53..af68efdbbfad 100644
--- a/Documentation/filesystems/configfs/configfs.txt
+++ b/Documentation/filesystems/configfs/configfs.txt
@@ -160,12 +160,6 @@ among other things.  For that, it needs a type.
 
 	struct configfs_item_operations {
 		void (*release)(struct config_item *);
-		ssize_t (*show_attribute)(struct config_item *,
-					  struct configfs_attribute *,
-					  char *);
-		ssize_t (*store_attribute)(struct config_item *,
-					   struct configfs_attribute *,
-					   const char *, size_t);
 		int (*allow_link)(struct config_item *src,
 				  struct config_item *target);
 		int (*drop_link)(struct config_item *src,
@@ -183,9 +177,7 @@ The most basic function of a config_item_type is to define what
 operations can be performed on a config_item.  All items that have been
 allocated dynamically will need to provide the ct_item_ops->release()
 method.  This method is called when the config_item's reference count
-reaches zero.  Items that wish to display an attribute need to provide
-the ct_item_ops->show_attribute() method.  Similarly, storing a new
-attribute value uses the store_attribute() method.
+reaches zero.
 
 [struct configfs_attribute]
 
@@ -193,6 +185,8 @@ attribute value uses the store_attribute() method.
 		char                    *ca_name;
 		struct module           *ca_owner;
 		umode_t                  ca_mode;
+		ssize_t (*show)(struct config_item *, char *);
+		ssize_t (*store)(struct config_item *, const char *, size_t);
 	};
 
 When a config_item wants an attribute to appear as a file in the item's
@@ -202,10 +196,10 @@ config_item_type->ct_attrs.  When the item appears in configfs, the
 attribute file will appear with the configfs_attribute->ca_name
 filename.  configfs_attribute->ca_mode specifies the file permissions.
 
-If an attribute is readable and the config_item provides a
-ct_item_ops->show_attribute() method, that method will be called
-whenever userspace asks for a read(2) on the attribute.  The converse
-will happen for write(2).
+If an attribute is readable and provides a ->show method, that method will
+be called whenever userspace asks for a read(2) on the attribute.  If an
+attribute is writable and provides a ->store  method, that method will be
+be called whenever userspace asks for a write(2) on the attribute.
 
 [struct config_group]
 
@@ -311,20 +305,10 @@ the subsystem must be ready for it.
 [An Example]
 
 The best example of these basic concepts is the simple_children
-subsystem/group and the simple_child item in configfs_example_explicit.c
-and configfs_example_macros.c.  It shows a trivial object displaying and
-storing an attribute, and a simple group creating and destroying these
-children.
-
-The only difference between configfs_example_explicit.c and
-configfs_example_macros.c is how the attributes of the childless item
-are defined.  The childless item has extended attributes, each with
-their own show()/store() operation.  This follows a convention commonly
-used in sysfs.  configfs_example_explicit.c creates these attributes
-by explicitly defining the structures involved.  Conversely
-configfs_example_macros.c uses some convenience macros from configfs.h
-to define the attributes.  These macros are similar to their sysfs
-counterparts.
+subsystem/group and the simple_child item in
+samples/configfs/configfs_sample.c. It shows a trivial object displaying
+and storing an attribute, and a simple group creating and destroying
+these children.
 
 [Hierarchy Navigation and the Subsystem Mutex]
 
diff --git a/Documentation/filesystems/configfs/configfs_example_explicit.c b/Documentation/filesystems/configfs/configfs_example_explicit.c
deleted file mode 100644
index 1420233dfa55..000000000000
--- a/Documentation/filesystems/configfs/configfs_example_explicit.c
+++ /dev/null
@@ -1,483 +0,0 @@
-/*
- * vim: noexpandtab ts=8 sts=0 sw=8:
- *
- * configfs_example_explicit.c - This file is a demonstration module
- *      containing a number of configfs subsystems.  It explicitly defines
- *      each structure without using the helper macros defined in
- *      configfs.h.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
- * Based on sysfs:
- * 	sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
- *
- * configfs Copyright (C) 2005 Oracle.  All rights reserved.
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-
-#include <linux/configfs.h>
-
-
-
-/*
- * 01-childless
- *
- * This first example is a childless subsystem.  It cannot create
- * any config_items.  It just has attributes.
- *
- * Note that we are enclosing the configfs_subsystem inside a container.
- * This is not necessary if a subsystem has no attributes directly
- * on the subsystem.  See the next example, 02-simple-children, for
- * such a subsystem.
- */
-
-struct childless {
-	struct configfs_subsystem subsys;
-	int showme;
-	int storeme;
-};
-
-struct childless_attribute {
-	struct configfs_attribute attr;
-	ssize_t (*show)(struct childless *, char *);
-	ssize_t (*store)(struct childless *, const char *, size_t);
-};
-
-static inline struct childless *to_childless(struct config_item *item)
-{
-	return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct childless, subsys) : NULL;
-}
-
-static ssize_t childless_showme_read(struct childless *childless,
-				     char *page)
-{
-	ssize_t pos;
-
-	pos = sprintf(page, "%d\n", childless->showme);
-	childless->showme++;
-
-	return pos;
-}
-
-static ssize_t childless_storeme_read(struct childless *childless,
-				      char *page)
-{
-	return sprintf(page, "%d\n", childless->storeme);
-}
-
-static ssize_t childless_storeme_write(struct childless *childless,
-				       const char *page,
-				       size_t count)
-{
-	unsigned long tmp;
-	char *p = (char *) page;
-
-	tmp = simple_strtoul(p, &p, 10);
-	if ((*p != '\0') && (*p != '\n'))
-		return -EINVAL;
-
-	if (tmp > INT_MAX)
-		return -ERANGE;
-
-	childless->storeme = tmp;
-
-	return count;
-}
-
-static ssize_t childless_description_read(struct childless *childless,
-					  char *page)
-{
-	return sprintf(page,
-"[01-childless]\n"
-"\n"
-"The childless subsystem is the simplest possible subsystem in\n"
-"configfs.  It does not support the creation of child config_items.\n"
-"It only has a few attributes.  In fact, it isn't much different\n"
-"than a directory in /proc.\n");
-}
-
-static struct childless_attribute childless_attr_showme = {
-	.attr	= { .ca_owner = THIS_MODULE, .ca_name = "showme", .ca_mode = S_IRUGO },
-	.show	= childless_showme_read,
-};
-static struct childless_attribute childless_attr_storeme = {
-	.attr	= { .ca_owner = THIS_MODULE, .ca_name = "storeme", .ca_mode = S_IRUGO | S_IWUSR },
-	.show	= childless_storeme_read,
-	.store	= childless_storeme_write,
-};
-static struct childless_attribute childless_attr_description = {
-	.attr = { .ca_owner = THIS_MODULE, .ca_name = "description", .ca_mode = S_IRUGO },
-	.show = childless_description_read,
-};
-
-static struct configfs_attribute *childless_attrs[] = {
-	&childless_attr_showme.attr,
-	&childless_attr_storeme.attr,
-	&childless_attr_description.attr,
-	NULL,
-};
-
-static ssize_t childless_attr_show(struct config_item *item,
-				   struct configfs_attribute *attr,
-				   char *page)
-{
-	struct childless *childless = to_childless(item);
-	struct childless_attribute *childless_attr =
-		container_of(attr, struct childless_attribute, attr);
-	ssize_t ret = 0;
-
-	if (childless_attr->show)
-		ret = childless_attr->show(childless, page);
-	return ret;
-}
-
-static ssize_t childless_attr_store(struct config_item *item,
-				    struct configfs_attribute *attr,
-				    const char *page, size_t count)
-{
-	struct childless *childless = to_childless(item);
-	struct childless_attribute *childless_attr =
-		container_of(attr, struct childless_attribute, attr);
-	ssize_t ret = -EINVAL;
-
-	if (childless_attr->store)
-		ret = childless_attr->store(childless, page, count);
-	return ret;
-}
-
-static struct configfs_item_operations childless_item_ops = {
-	.show_attribute		= childless_attr_show,
-	.store_attribute	= childless_attr_store,
-};
-
-static struct config_item_type childless_type = {
-	.ct_item_ops	= &childless_item_ops,
-	.ct_attrs	= childless_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-static struct childless childless_subsys = {
-	.subsys = {
-		.su_group = {
-			.cg_item = {
-				.ci_namebuf = "01-childless",
-				.ci_type = &childless_type,
-			},
-		},
-	},
-};
-
-
-/* ----------------------------------------------------------------- */
-
-/*
- * 02-simple-children
- *
- * This example merely has a simple one-attribute child.  Note that
- * there is no extra attribute structure, as the child's attribute is
- * known from the get-go.  Also, there is no container for the
- * subsystem, as it has no attributes of its own.
- */
-
-struct simple_child {
-	struct config_item item;
-	int storeme;
-};
-
-static inline struct simple_child *to_simple_child(struct config_item *item)
-{
-	return item ? container_of(item, struct simple_child, item) : NULL;
-}
-
-static struct configfs_attribute simple_child_attr_storeme = {
-	.ca_owner = THIS_MODULE,
-	.ca_name = "storeme",
-	.ca_mode = S_IRUGO | S_IWUSR,
-};
-
-static struct configfs_attribute *simple_child_attrs[] = {
-	&simple_child_attr_storeme,
-	NULL,
-};
-
-static ssize_t simple_child_attr_show(struct config_item *item,
-				      struct configfs_attribute *attr,
-				      char *page)
-{
-	ssize_t count;
-	struct simple_child *simple_child = to_simple_child(item);
-
-	count = sprintf(page, "%d\n", simple_child->storeme);
-
-	return count;
-}
-
-static ssize_t simple_child_attr_store(struct config_item *item,
-				       struct configfs_attribute *attr,
-				       const char *page, size_t count)
-{
-	struct simple_child *simple_child = to_simple_child(item);
-	unsigned long tmp;
-	char *p = (char *) page;
-
-	tmp = simple_strtoul(p, &p, 10);
-	if (!p || (*p && (*p != '\n')))
-		return -EINVAL;
-
-	if (tmp > INT_MAX)
-		return -ERANGE;
-
-	simple_child->storeme = tmp;
-
-	return count;
-}
-
-static void simple_child_release(struct config_item *item)
-{
-	kfree(to_simple_child(item));
-}
-
-static struct configfs_item_operations simple_child_item_ops = {
-	.release		= simple_child_release,
-	.show_attribute		= simple_child_attr_show,
-	.store_attribute	= simple_child_attr_store,
-};
-
-static struct config_item_type simple_child_type = {
-	.ct_item_ops	= &simple_child_item_ops,
-	.ct_attrs	= simple_child_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-
-struct simple_children {
-	struct config_group group;
-};
-
-static inline struct simple_children *to_simple_children(struct config_item *item)
-{
-	return item ? container_of(to_config_group(item), struct simple_children, group) : NULL;
-}
-
-static struct config_item *simple_children_make_item(struct config_group *group, const char *name)
-{
-	struct simple_child *simple_child;
-
-	simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
-	if (!simple_child)
-		return ERR_PTR(-ENOMEM);
-
-	config_item_init_type_name(&simple_child->item, name,
-				   &simple_child_type);
-
-	simple_child->storeme = 0;
-
-	return &simple_child->item;
-}
-
-static struct configfs_attribute simple_children_attr_description = {
-	.ca_owner = THIS_MODULE,
-	.ca_name = "description",
-	.ca_mode = S_IRUGO,
-};
-
-static struct configfs_attribute *simple_children_attrs[] = {
-	&simple_children_attr_description,
-	NULL,
-};
-
-static ssize_t simple_children_attr_show(struct config_item *item,
-					 struct configfs_attribute *attr,
-					 char *page)
-{
-	return sprintf(page,
-"[02-simple-children]\n"
-"\n"
-"This subsystem allows the creation of child config_items.  These\n"
-"items have only one attribute that is readable and writeable.\n");
-}
-
-static void simple_children_release(struct config_item *item)
-{
-	kfree(to_simple_children(item));
-}
-
-static struct configfs_item_operations simple_children_item_ops = {
-	.release	= simple_children_release,
-	.show_attribute	= simple_children_attr_show,
-};
-
-/*
- * Note that, since no extra work is required on ->drop_item(),
- * no ->drop_item() is provided.
- */
-static struct configfs_group_operations simple_children_group_ops = {
-	.make_item	= simple_children_make_item,
-};
-
-static struct config_item_type simple_children_type = {
-	.ct_item_ops	= &simple_children_item_ops,
-	.ct_group_ops	= &simple_children_group_ops,
-	.ct_attrs	= simple_children_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-static struct configfs_subsystem simple_children_subsys = {
-	.su_group = {
-		.cg_item = {
-			.ci_namebuf = "02-simple-children",
-			.ci_type = &simple_children_type,
-		},
-	},
-};
-
-
-/* ----------------------------------------------------------------- */
-
-/*
- * 03-group-children
- *
- * This example reuses the simple_children group from above.  However,
- * the simple_children group is not the subsystem itself, it is a
- * child of the subsystem.  Creation of a group in the subsystem creates
- * a new simple_children group.  That group can then have simple_child
- * children of its own.
- */
-
-static struct config_group *group_children_make_group(struct config_group *group, const char *name)
-{
-	struct simple_children *simple_children;
-
-	simple_children = kzalloc(sizeof(struct simple_children),
-				  GFP_KERNEL);
-	if (!simple_children)
-		return ERR_PTR(-ENOMEM);
-
-	config_group_init_type_name(&simple_children->group, name,
-				    &simple_children_type);
-
-	return &simple_children->group;
-}
-
-static struct configfs_attribute group_children_attr_description = {
-	.ca_owner = THIS_MODULE,
-	.ca_name = "description",
-	.ca_mode = S_IRUGO,
-};
-
-static struct configfs_attribute *group_children_attrs[] = {
-	&group_children_attr_description,
-	NULL,
-};
-
-static ssize_t group_children_attr_show(struct config_item *item,
-					struct configfs_attribute *attr,
-					char *page)
-{
-	return sprintf(page,
-"[03-group-children]\n"
-"\n"
-"This subsystem allows the creation of child config_groups.  These\n"
-"groups are like the subsystem simple-children.\n");
-}
-
-static struct configfs_item_operations group_children_item_ops = {
-	.show_attribute	= group_children_attr_show,
-};
-
-/*
- * Note that, since no extra work is required on ->drop_item(),
- * no ->drop_item() is provided.
- */
-static struct configfs_group_operations group_children_group_ops = {
-	.make_group	= group_children_make_group,
-};
-
-static struct config_item_type group_children_type = {
-	.ct_item_ops	= &group_children_item_ops,
-	.ct_group_ops	= &group_children_group_ops,
-	.ct_attrs	= group_children_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-static struct configfs_subsystem group_children_subsys = {
-	.su_group = {
-		.cg_item = {
-			.ci_namebuf = "03-group-children",
-			.ci_type = &group_children_type,
-		},
-	},
-};
-
-/* ----------------------------------------------------------------- */
-
-/*
- * We're now done with our subsystem definitions.
- * For convenience in this module, here's a list of them all.  It
- * allows the init function to easily register them.  Most modules
- * will only have one subsystem, and will only call register_subsystem
- * on it directly.
- */
-static struct configfs_subsystem *example_subsys[] = {
-	&childless_subsys.subsys,
-	&simple_children_subsys,
-	&group_children_subsys,
-	NULL,
-};
-
-static int __init configfs_example_init(void)
-{
-	int ret;
-	int i;
-	struct configfs_subsystem *subsys;
-
-	for (i = 0; example_subsys[i]; i++) {
-		subsys = example_subsys[i];
-
-		config_group_init(&subsys->su_group);
-		mutex_init(&subsys->su_mutex);
-		ret = configfs_register_subsystem(subsys);
-		if (ret) {
-			printk(KERN_ERR "Error %d while registering subsystem %s\n",
-			       ret,
-			       subsys->su_group.cg_item.ci_namebuf);
-			goto out_unregister;
-		}
-	}
-
-	return 0;
-
-out_unregister:
-	for (i--; i >= 0; i--)
-		configfs_unregister_subsystem(example_subsys[i]);
-
-	return ret;
-}
-
-static void __exit configfs_example_exit(void)
-{
-	int i;
-
-	for (i = 0; example_subsys[i]; i++)
-		configfs_unregister_subsystem(example_subsys[i]);
-}
-
-module_init(configfs_example_init);
-module_exit(configfs_example_exit);
-MODULE_LICENSE("GPL");
diff --git a/Documentation/filesystems/configfs/configfs_example_macros.c b/Documentation/filesystems/configfs/configfs_example_macros.c
deleted file mode 100644
index 327dfbc640a9..000000000000
--- a/Documentation/filesystems/configfs/configfs_example_macros.c
+++ /dev/null
@@ -1,446 +0,0 @@
-/*
- * vim: noexpandtab ts=8 sts=0 sw=8:
- *
- * configfs_example_macros.c - This file is a demonstration module
- *      containing a number of configfs subsystems.  It uses the helper
- *      macros defined by configfs.h
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
- * Based on sysfs:
- * 	sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
- *
- * configfs Copyright (C) 2005 Oracle.  All rights reserved.
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-
-#include <linux/configfs.h>
-
-
-
-/*
- * 01-childless
- *
- * This first example is a childless subsystem.  It cannot create
- * any config_items.  It just has attributes.
- *
- * Note that we are enclosing the configfs_subsystem inside a container.
- * This is not necessary if a subsystem has no attributes directly
- * on the subsystem.  See the next example, 02-simple-children, for
- * such a subsystem.
- */
-
-struct childless {
-	struct configfs_subsystem subsys;
-	int showme;
-	int storeme;
-};
-
-static inline struct childless *to_childless(struct config_item *item)
-{
-	return item ? container_of(to_configfs_subsystem(to_config_group(item)), struct childless, subsys) : NULL;
-}
-
-CONFIGFS_ATTR_STRUCT(childless);
-#define CHILDLESS_ATTR(_name, _mode, _show, _store)	\
-struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR(_name, _mode, _show, _store)
-#define CHILDLESS_ATTR_RO(_name, _show)	\
-struct childless_attribute childless_attr_##_name = __CONFIGFS_ATTR_RO(_name, _show);
-
-static ssize_t childless_showme_read(struct childless *childless,
-				     char *page)
-{
-	ssize_t pos;
-
-	pos = sprintf(page, "%d\n", childless->showme);
-	childless->showme++;
-
-	return pos;
-}
-
-static ssize_t childless_storeme_read(struct childless *childless,
-				      char *page)
-{
-	return sprintf(page, "%d\n", childless->storeme);
-}
-
-static ssize_t childless_storeme_write(struct childless *childless,
-				       const char *page,
-				       size_t count)
-{
-	unsigned long tmp;
-	char *p = (char *) page;
-
-	tmp = simple_strtoul(p, &p, 10);
-	if (!p || (*p && (*p != '\n')))
-		return -EINVAL;
-
-	if (tmp > INT_MAX)
-		return -ERANGE;
-
-	childless->storeme = tmp;
-
-	return count;
-}
-
-static ssize_t childless_description_read(struct childless *childless,
-					  char *page)
-{
-	return sprintf(page,
-"[01-childless]\n"
-"\n"
-"The childless subsystem is the simplest possible subsystem in\n"
-"configfs.  It does not support the creation of child config_items.\n"
-"It only has a few attributes.  In fact, it isn't much different\n"
-"than a directory in /proc.\n");
-}
-
-CHILDLESS_ATTR_RO(showme, childless_showme_read);
-CHILDLESS_ATTR(storeme, S_IRUGO | S_IWUSR, childless_storeme_read,
-	       childless_storeme_write);
-CHILDLESS_ATTR_RO(description, childless_description_read);
-
-static struct configfs_attribute *childless_attrs[] = {
-	&childless_attr_showme.attr,
-	&childless_attr_storeme.attr,
-	&childless_attr_description.attr,
-	NULL,
-};
-
-CONFIGFS_ATTR_OPS(childless);
-static struct configfs_item_operations childless_item_ops = {
-	.show_attribute		= childless_attr_show,
-	.store_attribute	= childless_attr_store,
-};
-
-static struct config_item_type childless_type = {
-	.ct_item_ops	= &childless_item_ops,
-	.ct_attrs	= childless_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-static struct childless childless_subsys = {
-	.subsys = {
-		.su_group = {
-			.cg_item = {
-				.ci_namebuf = "01-childless",
-				.ci_type = &childless_type,
-			},
-		},
-	},
-};
-
-
-/* ----------------------------------------------------------------- */
-
-/*
- * 02-simple-children
- *
- * This example merely has a simple one-attribute child.  Note that
- * there is no extra attribute structure, as the child's attribute is
- * known from the get-go.  Also, there is no container for the
- * subsystem, as it has no attributes of its own.
- */
-
-struct simple_child {
-	struct config_item item;
-	int storeme;
-};
-
-static inline struct simple_child *to_simple_child(struct config_item *item)
-{
-	return item ? container_of(item, struct simple_child, item) : NULL;
-}
-
-static struct configfs_attribute simple_child_attr_storeme = {
-	.ca_owner = THIS_MODULE,
-	.ca_name = "storeme",
-	.ca_mode = S_IRUGO | S_IWUSR,
-};
-
-static struct configfs_attribute *simple_child_attrs[] = {
-	&simple_child_attr_storeme,
-	NULL,
-};
-
-static ssize_t simple_child_attr_show(struct config_item *item,
-				      struct configfs_attribute *attr,
-				      char *page)
-{
-	ssize_t count;
-	struct simple_child *simple_child = to_simple_child(item);
-
-	count = sprintf(page, "%d\n", simple_child->storeme);
-
-	return count;
-}
-
-static ssize_t simple_child_attr_store(struct config_item *item,
-				       struct configfs_attribute *attr,
-				       const char *page, size_t count)
-{
-	struct simple_child *simple_child = to_simple_child(item);
-	unsigned long tmp;
-	char *p = (char *) page;
-
-	tmp = simple_strtoul(p, &p, 10);
-	if (!p || (*p && (*p != '\n')))
-		return -EINVAL;
-
-	if (tmp > INT_MAX)
-		return -ERANGE;
-
-	simple_child->storeme = tmp;
-
-	return count;
-}
-
-static void simple_child_release(struct config_item *item)
-{
-	kfree(to_simple_child(item));
-}
-
-static struct configfs_item_operations simple_child_item_ops = {
-	.release		= simple_child_release,
-	.show_attribute		= simple_child_attr_show,
-	.store_attribute	= simple_child_attr_store,
-};
-
-static struct config_item_type simple_child_type = {
-	.ct_item_ops	= &simple_child_item_ops,
-	.ct_attrs	= simple_child_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-
-struct simple_children {
-	struct config_group group;
-};
-
-static inline struct simple_children *to_simple_children(struct config_item *item)
-{
-	return item ? container_of(to_config_group(item), struct simple_children, group) : NULL;
-}
-
-static struct config_item *simple_children_make_item(struct config_group *group, const char *name)
-{
-	struct simple_child *simple_child;
-
-	simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
-	if (!simple_child)
-		return ERR_PTR(-ENOMEM);
-
-	config_item_init_type_name(&simple_child->item, name,
-				   &simple_child_type);
-
-	simple_child->storeme = 0;
-
-	return &simple_child->item;
-}
-
-static struct configfs_attribute simple_children_attr_description = {
-	.ca_owner = THIS_MODULE,
-	.ca_name = "description",
-	.ca_mode = S_IRUGO,
-};
-
-static struct configfs_attribute *simple_children_attrs[] = {
-	&simple_children_attr_description,
-	NULL,
-};
-
-static ssize_t simple_children_attr_show(struct config_item *item,
-					 struct configfs_attribute *attr,
-					 char *page)
-{
-	return sprintf(page,
-"[02-simple-children]\n"
-"\n"
-"This subsystem allows the creation of child config_items.  These\n"
-"items have only one attribute that is readable and writeable.\n");
-}
-
-static void simple_children_release(struct config_item *item)
-{
-	kfree(to_simple_children(item));
-}
-
-static struct configfs_item_operations simple_children_item_ops = {
-	.release	= simple_children_release,
-	.show_attribute	= simple_children_attr_show,
-};
-
-/*
- * Note that, since no extra work is required on ->drop_item(),
- * no ->drop_item() is provided.
- */
-static struct configfs_group_operations simple_children_group_ops = {
-	.make_item	= simple_children_make_item,
-};
-
-static struct config_item_type simple_children_type = {
-	.ct_item_ops	= &simple_children_item_ops,
-	.ct_group_ops	= &simple_children_group_ops,
-	.ct_attrs	= simple_children_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-static struct configfs_subsystem simple_children_subsys = {
-	.su_group = {
-		.cg_item = {
-			.ci_namebuf = "02-simple-children",
-			.ci_type = &simple_children_type,
-		},
-	},
-};
-
-
-/* ----------------------------------------------------------------- */
-
-/*
- * 03-group-children
- *
- * This example reuses the simple_children group from above.  However,
- * the simple_children group is not the subsystem itself, it is a
- * child of the subsystem.  Creation of a group in the subsystem creates
- * a new simple_children group.  That group can then have simple_child
- * children of its own.
- */
-
-static struct config_group *group_children_make_group(struct config_group *group, const char *name)
-{
-	struct simple_children *simple_children;
-
-	simple_children = kzalloc(sizeof(struct simple_children),
-				  GFP_KERNEL);
-	if (!simple_children)
-		return ERR_PTR(-ENOMEM);
-
-	config_group_init_type_name(&simple_children->group, name,
-				    &simple_children_type);
-
-	return &simple_children->group;
-}
-
-static struct configfs_attribute group_children_attr_description = {
-	.ca_owner = THIS_MODULE,
-	.ca_name = "description",
-	.ca_mode = S_IRUGO,
-};
-
-static struct configfs_attribute *group_children_attrs[] = {
-	&group_children_attr_description,
-	NULL,
-};
-
-static ssize_t group_children_attr_show(struct config_item *item,
-					struct configfs_attribute *attr,
-					char *page)
-{
-	return sprintf(page,
-"[03-group-children]\n"
-"\n"
-"This subsystem allows the creation of child config_groups.  These\n"
-"groups are like the subsystem simple-children.\n");
-}
-
-static struct configfs_item_operations group_children_item_ops = {
-	.show_attribute	= group_children_attr_show,
-};
-
-/*
- * Note that, since no extra work is required on ->drop_item(),
- * no ->drop_item() is provided.
- */
-static struct configfs_group_operations group_children_group_ops = {
-	.make_group	= group_children_make_group,
-};
-
-static struct config_item_type group_children_type = {
-	.ct_item_ops	= &group_children_item_ops,
-	.ct_group_ops	= &group_children_group_ops,
-	.ct_attrs	= group_children_attrs,
-	.ct_owner	= THIS_MODULE,
-};
-
-static struct configfs_subsystem group_children_subsys = {
-	.su_group = {
-		.cg_item = {
-			.ci_namebuf = "03-group-children",
-			.ci_type = &group_children_type,
-		},
-	},
-};
-
-/* ----------------------------------------------------------------- */
-
-/*
- * We're now done with our subsystem definitions.
- * For convenience in this module, here's a list of them all.  It
- * allows the init function to easily register them.  Most modules
- * will only have one subsystem, and will only call register_subsystem
- * on it directly.
- */
-static struct configfs_subsystem *example_subsys[] = {
-	&childless_subsys.subsys,
-	&simple_children_subsys,
-	&group_children_subsys,
-	NULL,
-};
-
-static int __init configfs_example_init(void)
-{
-	int ret;
-	int i;
-	struct configfs_subsystem *subsys;
-
-	for (i = 0; example_subsys[i]; i++) {
-		subsys = example_subsys[i];
-
-		config_group_init(&subsys->su_group);
-		mutex_init(&subsys->su_mutex);
-		ret = configfs_register_subsystem(subsys);
-		if (ret) {
-			printk(KERN_ERR "Error %d while registering subsystem %s\n",
-			       ret,
-			       subsys->su_group.cg_item.ci_namebuf);
-			goto out_unregister;
-		}
-	}
-
-	return 0;
-
-out_unregister:
-	for (i--; i >= 0; i--)
-		configfs_unregister_subsystem(example_subsys[i]);
-
-	return ret;
-}
-
-static void __exit configfs_example_exit(void)
-{
-	int i;
-
-	for (i = 0; example_subsys[i]; i++)
-		configfs_unregister_subsystem(example_subsys[i]);
-}
-
-module_init(configfs_example_init);
-module_exit(configfs_example_exit);
-MODULE_LICENSE("GPL");