1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
|
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* configfs.h - definitions for the device driver filesystem
*
* 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
*
* Based on kobject.h:
* Copyright (c) 2002-2003 Patrick Mochel
* Copyright (c) 2002-2003 Open Source Development Labs
*
* configfs Copyright (C) 2005 Oracle. All rights reserved.
*
* Please read Documentation/filesystems/configfs/configfs.txt before using
* the configfs interface, ESPECIALLY the parts about reference counts and
* item destructors.
*/
#ifndef _CONFIGFS_H_
#define _CONFIGFS_H_
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/kref.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/atomic.h>
#define CONFIGFS_ITEM_NAME_LEN 20
struct module;
struct configfs_item_operations;
struct configfs_group_operations;
struct configfs_attribute;
struct configfs_subsystem;
struct config_item {
char *ci_name;
char ci_namebuf[CONFIGFS_ITEM_NAME_LEN];
struct kref ci_kref;
struct list_head ci_entry;
struct config_item *ci_parent;
struct config_group *ci_group;
struct config_item_type *ci_type;
struct dentry *ci_dentry;
};
extern __printf(2, 3)
int config_item_set_name(struct config_item *, const char *, ...);
static inline char *config_item_name(struct config_item * item)
{
return item->ci_name;
}
extern void config_item_init_type_name(struct config_item *item,
const char *name,
struct config_item_type *type);
extern struct config_item * config_item_get(struct config_item *);
extern void config_item_put(struct config_item *);
struct config_item_type {
struct module *ct_owner;
struct configfs_item_operations *ct_item_ops;
struct configfs_group_operations *ct_group_ops;
struct configfs_attribute **ct_attrs;
};
/**
* group - a group of config_items of a specific type, belonging
* to a specific subsystem.
*/
struct config_group {
struct config_item cg_item;
struct list_head cg_children;
struct configfs_subsystem *cg_subsys;
struct config_group **default_groups;
};
extern void config_group_init(struct config_group *group);
extern void config_group_init_type_name(struct config_group *group,
const char *name,
struct config_item_type *type);
static inline struct config_group *to_config_group(struct config_item *item)
{
return item ? container_of(item,struct config_group,cg_item) : NULL;
}
static inline struct config_group *config_group_get(struct config_group *group)
{
return group ? to_config_group(config_item_get(&group->cg_item)) : NULL;
}
static inline void config_group_put(struct config_group *group)
{
config_item_put(&group->cg_item);
}
extern struct config_item *config_group_find_item(struct config_group *,
const char *);
struct configfs_attribute {
const char *ca_name;
struct module *ca_owner;
umode_t ca_mode;
};
/*
* 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).
* Groups supply one of make_group() and make_item(). If the
* group supports make_group(), one can create group children. If it
* supports make_item(), one can create config_item children. make_group()
* and make_item() return ERR_PTR() on errors. If it has
* default_groups on group->default_groups, it has automatically created
* group children. default_groups may coexist alongsize make_group() or
* make_item(), but if the group wishes to have only default_groups
* children (disallowing mkdir(2)), it need not provide either function.
* If the group has commit(), it supports pending and committed (active)
* items.
*/
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);
};
struct configfs_group_operations {
struct config_item *(*make_item)(struct config_group *group, const char *name);
struct config_group *(*make_group)(struct config_group *group, const char *name);
int (*commit_item)(struct config_item *item);
void (*disconnect_notify)(struct config_group *group, struct config_item *item);
void (*drop_item)(struct config_group *group, struct config_item *item);
};
struct configfs_subsystem {
struct config_group su_group;
struct mutex su_mutex;
};
static inline struct configfs_subsystem *to_configfs_subsystem(struct config_group *group)
{
return group ?
container_of(group, struct configfs_subsystem, su_group) :
NULL;
}
int configfs_register_subsystem(struct configfs_subsystem *subsys);
void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
/* These functions can sleep and can alloc with GFP_KERNEL */
/* WARNING: These cannot be called underneath configfs callbacks!! */
int configfs_depend_item(struct configfs_subsystem *subsys, struct config_item *target);
void configfs_undepend_item(struct configfs_subsystem *subsys, struct config_item *target);
#endif /* _CONFIGFS_H_ */
|
