-subdir-y := configfs
-
# List of programs to build
hostprogs-y := dnotify_test
+++ /dev/null
-ifneq ($(CONFIG_CONFIGFS_FS),)
-obj-m += configfs_example_explicit.o configfs_example_macros.o
-endif
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,
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]
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
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]
[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]
+++ /dev/null
-/*
- * 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");
+++ /dev/null
-/*
- * 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");
{
struct configfs_attribute * attr = to_attr(dentry);
struct config_item * item = to_item(dentry->d_parent);
- struct configfs_item_operations * ops = buffer->ops;
int ret = 0;
ssize_t count;
if (!buffer->page)
return -ENOMEM;
- if (ops->show_attribute)
- count = ops->show_attribute(item, attr, buffer->page);
- else
- count = attr->show(item, buffer->page);
+ count = attr->show(item, buffer->page);
buffer->needs_read_fill = 0;
BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE);
{
struct configfs_attribute * attr = to_attr(dentry);
struct config_item * item = to_item(dentry->d_parent);
- struct configfs_item_operations * ops = buffer->ops;
- if (ops->store_attribute)
- return ops->store_attribute(item, attr, buffer->page, count);
return attr->store(item, buffer->page, count);
}
* and we must have a store method.
*/
if (file->f_mode & FMODE_WRITE) {
- if (!(inode->i_mode & S_IWUGO) ||
- (!ops->store_attribute && !attr->store))
+ if (!(inode->i_mode & S_IWUGO) || !attr->store)
goto Eaccess;
}
* must be a show method for it.
*/
if (file->f_mode & FMODE_READ) {
- if (!(inode->i_mode & S_IRUGO) ||
- (!ops->show_attribute && !attr->show))
+ if (!(inode->i_mode & S_IRUGO) || !attr->show)
goto Eaccess;
}
.store = _pfx##_name##_store, \
}
-/*
- * Users often need to create attribute structures for their configurable
- * attributes, containing a configfs_attribute member and function pointers
- * for the show() and store() operations on that attribute. If they don't
- * need anything else on the extended attribute structure, they can use
- * this macro to define it The argument _item is the name of the
- * config_item structure.
- */
-#define CONFIGFS_ATTR_STRUCT(_item) \
-struct _item##_attribute { \
- struct configfs_attribute attr; \
- ssize_t (*show)(struct _item *, char *); \
- ssize_t (*store)(struct _item *, const char *, size_t); \
-}
-
-/*
- * With the extended attribute structure, users can use this macro
- * (similar to sysfs' __ATTR) to make defining attributes easier.
- * An example:
- * #define MYITEM_ATTR(_name, _mode, _show, _store) \
- * struct myitem_attribute childless_attr_##_name = \
- * __CONFIGFS_ATTR(_name, _mode, _show, _store)
- */
-#define __CONFIGFS_ATTR(_name, _mode, _show, _store) \
-{ \
- .attr = { \
- .ca_name = __stringify(_name), \
- .ca_mode = _mode, \
- .ca_owner = THIS_MODULE, \
- }, \
- .show = _show, \
- .store = _store, \
-}
-/* Here is a readonly version, only requiring a show() operation */
-#define __CONFIGFS_ATTR_RO(_name, _show) \
-{ \
- .attr = { \
- .ca_name = __stringify(_name), \
- .ca_mode = 0444, \
- .ca_owner = THIS_MODULE, \
- }, \
- .show = _show, \
-}
-
-/*
- * With these extended attributes, the simple show_attribute() and
- * store_attribute() operations need to call the show() and store() of the
- * attributes. This is a common pattern, so we provide a macro to define
- * them. The argument _item is the name of the config_item structure.
- * This macro expects the attributes to be named "struct <name>_attribute"
- * and the function to_<name>() to exist;
- */
-#define CONFIGFS_ATTR_OPS(_item) \
-static ssize_t _item##_attr_show(struct config_item *item, \
- struct configfs_attribute *attr, \
- char *page) \
-{ \
- struct _item *_item = to_##_item(item); \
- struct _item##_attribute *_item##_attr = \
- container_of(attr, struct _item##_attribute, attr); \
- ssize_t ret = 0; \
- \
- if (_item##_attr->show) \
- ret = _item##_attr->show(_item, page); \
- return ret; \
-} \
-static ssize_t _item##_attr_store(struct config_item *item, \
- struct configfs_attribute *attr, \
- const char *page, size_t count) \
-{ \
- struct _item *_item = to_##_item(item); \
- struct _item##_attribute *_item##_attr = \
- container_of(attr, struct _item##_attribute, attr); \
- ssize_t ret = -EINVAL; \
- \
- if (_item##_attr->store) \
- ret = _item##_attr->store(_item, page, count); \
- return ret; \
-}
-
/*
* If allow_link() exists, the item can symlink(2) out to other
* items. If the item is a group, it may support mkdir(2).
*/
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, struct config_item *target);
};
Builds a sample live patch that replaces the procfs handler
for /proc/cmdline to print "this has been live patched".
+config SAMPLE_CONFIGFS
+ tristate "Build configfs patching sample -- loadable modules only"
+ depends on CONFIGFS_FS && m
+ help
+ Builds a sample configfs interface.
+
endif # SAMPLES
# Makefile for Linux samples code
obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ trace_events/ livepatch/ \
- hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/
+ hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \
+ configfs/
--- /dev/null
+
+obj-$(CONFIG_SAMPLE_CONFIGFS) += configfs_sample.o
--- /dev/null
+/*
+ * 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;
+}
+
+static ssize_t childless_showme_show(struct config_item *item, char *page)
+{
+ struct childless *childless = to_childless(item);
+ ssize_t pos;
+
+ pos = sprintf(page, "%d\n", childless->showme);
+ childless->showme++;
+
+ return pos;
+}
+
+static ssize_t childless_storeme_show(struct config_item *item, char *page)
+{
+ return sprintf(page, "%d\n", to_childless(item)->storeme);
+}
+
+static ssize_t childless_storeme_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct childless *childless = to_childless(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;
+
+ childless->storeme = tmp;
+
+ return count;
+}
+
+static ssize_t childless_description_show(struct config_item *item, 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");
+}
+
+CONFIGFS_ATTR_RO(childless_, showme);
+CONFIGFS_ATTR(childless_, storeme);
+CONFIGFS_ATTR_RO(childless_, description);
+
+static struct configfs_attribute *childless_attrs[] = {
+ &childless_attr_showme,
+ &childless_attr_storeme,
+ &childless_attr_description,
+ NULL,
+};
+
+static struct config_item_type childless_type = {
+ .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 ssize_t simple_child_storeme_show(struct config_item *item, char *page)
+{
+ return sprintf(page, "%d\n", to_simple_child(item)->storeme);
+}
+
+static ssize_t simple_child_storeme_store(struct config_item *item,
+ 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;
+}
+
+CONFIGFS_ATTR(simple_child_, storeme);
+
+static struct configfs_attribute *simple_child_attrs[] = {
+ &simple_child_attr_storeme,
+ NULL,
+};
+
+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,
+};
+
+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 ssize_t simple_children_description_show(struct config_item *item,
+ 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");
+}
+
+CONFIGFS_ATTR_RO(simple_children_, description);
+
+static struct configfs_attribute *simple_children_attrs[] = {
+ &simple_children_attr_description,
+ NULL,
+};
+
+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,
+};
+
+/*
+ * 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 ssize_t group_children_description_show(struct config_item *item,
+ 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");
+}
+
+CONFIGFS_ATTR_RO(group_children_, description);
+
+static struct configfs_attribute *group_children_attrs[] = {
+ &group_children_attr_description,
+ NULL,
+};
+
+/*
+ * 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_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");
projects / linux-drm-fsl-dcu.git / commitdiff