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![Bartosz Golaszewski](/assets/img/avatar_default.png)
A proposition of implementation of committable items has been rejected due to the gpio-sim module being the only user and configfs not getting much development in general. In that case, let's remove the notion of committable items from docs and headers. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
270 lines
8.4 KiB
C
270 lines
8.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* configfs.h - definitions for the device driver filesystem
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*
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* Based on sysfs:
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* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
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*
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* Based on kobject.h:
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* Copyright (c) 2002-2003 Patrick Mochel
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* Copyright (c) 2002-2003 Open Source Development Labs
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*
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* configfs Copyright (C) 2005 Oracle. All rights reserved.
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*
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* Please read Documentation/filesystems/configfs.rst before using
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* the configfs interface, ESPECIALLY the parts about reference counts and
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* item destructors.
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*/
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#ifndef _CONFIGFS_H_
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#define _CONFIGFS_H_
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#include <linux/stat.h> /* S_IRUGO */
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#include <linux/types.h> /* ssize_t */
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#include <linux/list.h> /* struct list_head */
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#include <linux/kref.h> /* struct kref */
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#include <linux/mutex.h> /* struct mutex */
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#define CONFIGFS_ITEM_NAME_LEN 20
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struct module;
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struct configfs_item_operations;
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struct configfs_group_operations;
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struct configfs_attribute;
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struct configfs_bin_attribute;
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struct configfs_subsystem;
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struct config_item {
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char *ci_name;
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char ci_namebuf[CONFIGFS_ITEM_NAME_LEN];
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struct kref ci_kref;
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struct list_head ci_entry;
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struct config_item *ci_parent;
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struct config_group *ci_group;
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const struct config_item_type *ci_type;
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struct dentry *ci_dentry;
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};
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extern __printf(2, 3)
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int config_item_set_name(struct config_item *, const char *, ...);
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static inline char *config_item_name(struct config_item * item)
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{
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return item->ci_name;
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}
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extern void config_item_init_type_name(struct config_item *item,
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const char *name,
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const struct config_item_type *type);
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extern struct config_item *config_item_get(struct config_item *);
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extern struct config_item *config_item_get_unless_zero(struct config_item *);
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extern void config_item_put(struct config_item *);
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struct config_item_type {
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struct module *ct_owner;
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struct configfs_item_operations *ct_item_ops;
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struct configfs_group_operations *ct_group_ops;
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struct configfs_attribute **ct_attrs;
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struct configfs_bin_attribute **ct_bin_attrs;
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};
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/**
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* group - a group of config_items of a specific type, belonging
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* to a specific subsystem.
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*/
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struct config_group {
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struct config_item cg_item;
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struct list_head cg_children;
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struct configfs_subsystem *cg_subsys;
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struct list_head default_groups;
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struct list_head group_entry;
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};
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extern void config_group_init(struct config_group *group);
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extern void config_group_init_type_name(struct config_group *group,
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const char *name,
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const struct config_item_type *type);
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static inline struct config_group *to_config_group(struct config_item *item)
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{
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return item ? container_of(item,struct config_group,cg_item) : NULL;
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}
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static inline struct config_group *config_group_get(struct config_group *group)
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{
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return group ? to_config_group(config_item_get(&group->cg_item)) : NULL;
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}
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static inline void config_group_put(struct config_group *group)
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{
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config_item_put(&group->cg_item);
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}
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extern struct config_item *config_group_find_item(struct config_group *,
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const char *);
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static inline void configfs_add_default_group(struct config_group *new_group,
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struct config_group *group)
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{
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list_add_tail(&new_group->group_entry, &group->default_groups);
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}
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struct configfs_attribute {
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const char *ca_name;
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struct module *ca_owner;
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umode_t ca_mode;
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ssize_t (*show)(struct config_item *, char *);
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ssize_t (*store)(struct config_item *, const char *, size_t);
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};
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#define CONFIGFS_ATTR(_pfx, _name) \
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static struct configfs_attribute _pfx##attr_##_name = { \
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.ca_name = __stringify(_name), \
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.ca_mode = S_IRUGO | S_IWUSR, \
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.ca_owner = THIS_MODULE, \
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.show = _pfx##_name##_show, \
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.store = _pfx##_name##_store, \
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}
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#define CONFIGFS_ATTR_RO(_pfx, _name) \
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static struct configfs_attribute _pfx##attr_##_name = { \
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.ca_name = __stringify(_name), \
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.ca_mode = S_IRUGO, \
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.ca_owner = THIS_MODULE, \
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.show = _pfx##_name##_show, \
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}
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#define CONFIGFS_ATTR_WO(_pfx, _name) \
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static struct configfs_attribute _pfx##attr_##_name = { \
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.ca_name = __stringify(_name), \
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.ca_mode = S_IWUSR, \
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.ca_owner = THIS_MODULE, \
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.store = _pfx##_name##_store, \
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}
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struct file;
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struct vm_area_struct;
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struct configfs_bin_attribute {
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struct configfs_attribute cb_attr; /* std. attribute */
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void *cb_private; /* for user */
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size_t cb_max_size; /* max core size */
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ssize_t (*read)(struct config_item *, void *, size_t);
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ssize_t (*write)(struct config_item *, const void *, size_t);
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};
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#define CONFIGFS_BIN_ATTR(_pfx, _name, _priv, _maxsz) \
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static struct configfs_bin_attribute _pfx##attr_##_name = { \
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.cb_attr = { \
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.ca_name = __stringify(_name), \
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.ca_mode = S_IRUGO | S_IWUSR, \
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.ca_owner = THIS_MODULE, \
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}, \
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.cb_private = _priv, \
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.cb_max_size = _maxsz, \
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.read = _pfx##_name##_read, \
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.write = _pfx##_name##_write, \
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}
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#define CONFIGFS_BIN_ATTR_RO(_pfx, _name, _priv, _maxsz) \
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static struct configfs_bin_attribute _pfx##attr_##_name = { \
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.cb_attr = { \
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.ca_name = __stringify(_name), \
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.ca_mode = S_IRUGO, \
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.ca_owner = THIS_MODULE, \
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}, \
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.cb_private = _priv, \
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.cb_max_size = _maxsz, \
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.read = _pfx##_name##_read, \
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}
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#define CONFIGFS_BIN_ATTR_WO(_pfx, _name, _priv, _maxsz) \
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static struct configfs_bin_attribute _pfx##attr_##_name = { \
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.cb_attr = { \
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.ca_name = __stringify(_name), \
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.ca_mode = S_IWUSR, \
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.ca_owner = THIS_MODULE, \
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}, \
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.cb_private = _priv, \
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.cb_max_size = _maxsz, \
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.write = _pfx##_name##_write, \
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}
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/*
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* If allow_link() exists, the item can symlink(2) out to other
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* items. If the item is a group, it may support mkdir(2).
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* Groups supply one of make_group() and make_item(). If the
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* group supports make_group(), one can create group children. If it
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* supports make_item(), one can create config_item children. make_group()
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* and make_item() return ERR_PTR() on errors. If it has
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* default_groups on group->default_groups, it has automatically created
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* group children. default_groups may coexist alongsize make_group() or
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* make_item(), but if the group wishes to have only default_groups
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* children (disallowing mkdir(2)), it need not provide either function.
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*/
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struct configfs_item_operations {
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void (*release)(struct config_item *);
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int (*allow_link)(struct config_item *src, struct config_item *target);
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void (*drop_link)(struct config_item *src, struct config_item *target);
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};
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struct configfs_group_operations {
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struct config_item *(*make_item)(struct config_group *group, const char *name);
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struct config_group *(*make_group)(struct config_group *group, const char *name);
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void (*disconnect_notify)(struct config_group *group, struct config_item *item);
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void (*drop_item)(struct config_group *group, struct config_item *item);
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};
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struct configfs_subsystem {
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struct config_group su_group;
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struct mutex su_mutex;
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};
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static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group)
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{
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return group ?
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container_of(group, struct configfs_subsystem, su_group) :
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NULL;
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}
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int configfs_register_subsystem(struct configfs_subsystem *subsys);
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void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
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int configfs_register_group(struct config_group *parent_group,
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struct config_group *group);
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void configfs_unregister_group(struct config_group *group);
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void configfs_remove_default_groups(struct config_group *group);
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struct config_group *
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configfs_register_default_group(struct config_group *parent_group,
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const char *name,
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const struct config_item_type *item_type);
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void configfs_unregister_default_group(struct config_group *group);
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/* These functions can sleep and can alloc with GFP_KERNEL */
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/* WARNING: These cannot be called underneath configfs callbacks!! */
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int configfs_depend_item(struct configfs_subsystem *subsys,
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struct config_item *target);
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void configfs_undepend_item(struct config_item *target);
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/*
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* These functions can sleep and can alloc with GFP_KERNEL
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* NOTE: These should be called only underneath configfs callbacks.
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* NOTE: First parameter is a caller's subsystem, not target's.
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* WARNING: These cannot be called on newly created item
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* (in make_group()/make_item() callback)
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*/
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int configfs_depend_item_unlocked(struct configfs_subsystem *caller_subsys,
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struct config_item *target);
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static inline void configfs_undepend_item_unlocked(struct config_item *target)
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{
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configfs_undepend_item(target);
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}
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#endif /* _CONFIGFS_H_ */
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