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7063fbf2 JB |
1 | /* |
2 | * vim: noexpandtab ts=8 sts=0 sw=8: | |
3 | * | |
ecb3d28c JB |
4 | * configfs_example_macros.c - This file is a demonstration module |
5 | * containing a number of configfs subsystems. It uses the helper | |
6 | * macros defined by configfs.h | |
7063fbf2 JB |
7 | * |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public | |
10 | * License as published by the Free Software Foundation; either | |
11 | * version 2 of the License, or (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public | |
19 | * License along with this program; if not, write to the | |
20 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
21 | * Boston, MA 021110-1307, USA. | |
22 | * | |
23 | * Based on sysfs: | |
24 | * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel | |
25 | * | |
26 | * configfs Copyright (C) 2005 Oracle. All rights reserved. | |
27 | */ | |
28 | ||
29 | #include <linux/init.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/slab.h> | |
32 | ||
33 | #include <linux/configfs.h> | |
34 | ||
35 | ||
36 | ||
37 | /* | |
38 | * 01-childless | |
39 | * | |
40 | * This first example is a childless subsystem. It cannot create | |
41 | * any config_items. It just has attributes. | |
42 | * | |
43 | * Note that we are enclosing the configfs_subsystem inside a container. | |
44 | * This is not necessary if a subsystem has no attributes directly | |
45 | * on the subsystem. See the next example, 02-simple-children, for | |
46 | * such a subsystem. | |
47 | */ | |
48 | ||
49 | struct childless { | |
50 | struct configfs_subsystem subsys; | |
51 | int showme; | |
52 | int storeme; | |
53 | }; | |
54 | ||
7063fbf2 JB |
55 | static inline struct childless *to_childless(struct config_item *item) |
56 | { | |
51798222 CH |
57 | return item ? container_of(to_configfs_subsystem(to_config_group(item)), |
58 | struct childless, subsys) : NULL; | |
7063fbf2 JB |
59 | } |
60 | ||
51798222 | 61 | static ssize_t childless_showme_show(struct config_item *item, char *page) |
7063fbf2 | 62 | { |
51798222 | 63 | struct childless *childless = to_childless(item); |
7063fbf2 JB |
64 | ssize_t pos; |
65 | ||
66 | pos = sprintf(page, "%d\n", childless->showme); | |
67 | childless->showme++; | |
68 | ||
69 | return pos; | |
70 | } | |
71 | ||
51798222 | 72 | static ssize_t childless_storeme_show(struct config_item *item, char *page) |
7063fbf2 | 73 | { |
51798222 | 74 | return sprintf(page, "%d\n", to_childless(item)->storeme); |
7063fbf2 JB |
75 | } |
76 | ||
51798222 CH |
77 | static ssize_t childless_storeme_store(struct config_item *item, |
78 | const char *page, size_t count) | |
7063fbf2 | 79 | { |
51798222 | 80 | struct childless *childless = to_childless(item); |
7063fbf2 JB |
81 | unsigned long tmp; |
82 | char *p = (char *) page; | |
83 | ||
84 | tmp = simple_strtoul(p, &p, 10); | |
85 | if (!p || (*p && (*p != '\n'))) | |
86 | return -EINVAL; | |
87 | ||
88 | if (tmp > INT_MAX) | |
89 | return -ERANGE; | |
90 | ||
91 | childless->storeme = tmp; | |
92 | ||
93 | return count; | |
94 | } | |
95 | ||
51798222 | 96 | static ssize_t childless_description_show(struct config_item *item, char *page) |
7063fbf2 JB |
97 | { |
98 | return sprintf(page, | |
99 | "[01-childless]\n" | |
100 | "\n" | |
101 | "The childless subsystem is the simplest possible subsystem in\n" | |
102 | "configfs. It does not support the creation of child config_items.\n" | |
103 | "It only has a few attributes. In fact, it isn't much different\n" | |
104 | "than a directory in /proc.\n"); | |
105 | } | |
106 | ||
51798222 CH |
107 | CONFIGFS_ATTR_RO(childless_, showme); |
108 | CONFIGFS_ATTR(childless_, storeme); | |
109 | CONFIGFS_ATTR_RO(childless_, description); | |
7063fbf2 JB |
110 | |
111 | static struct configfs_attribute *childless_attrs[] = { | |
51798222 CH |
112 | &childless_attr_showme, |
113 | &childless_attr_storeme, | |
114 | &childless_attr_description, | |
7063fbf2 JB |
115 | NULL, |
116 | }; | |
117 | ||
7063fbf2 | 118 | static struct config_item_type childless_type = { |
7063fbf2 JB |
119 | .ct_attrs = childless_attrs, |
120 | .ct_owner = THIS_MODULE, | |
121 | }; | |
122 | ||
123 | static struct childless childless_subsys = { | |
124 | .subsys = { | |
125 | .su_group = { | |
126 | .cg_item = { | |
127 | .ci_namebuf = "01-childless", | |
128 | .ci_type = &childless_type, | |
129 | }, | |
130 | }, | |
131 | }, | |
132 | }; | |
133 | ||
134 | ||
135 | /* ----------------------------------------------------------------- */ | |
136 | ||
137 | /* | |
138 | * 02-simple-children | |
139 | * | |
140 | * This example merely has a simple one-attribute child. Note that | |
141 | * there is no extra attribute structure, as the child's attribute is | |
142 | * known from the get-go. Also, there is no container for the | |
143 | * subsystem, as it has no attributes of its own. | |
144 | */ | |
145 | ||
146 | struct simple_child { | |
147 | struct config_item item; | |
148 | int storeme; | |
149 | }; | |
150 | ||
151 | static inline struct simple_child *to_simple_child(struct config_item *item) | |
152 | { | |
153 | return item ? container_of(item, struct simple_child, item) : NULL; | |
154 | } | |
155 | ||
51798222 | 156 | static ssize_t simple_child_storeme_show(struct config_item *item, char *page) |
7063fbf2 | 157 | { |
51798222 | 158 | return sprintf(page, "%d\n", to_simple_child(item)->storeme); |
7063fbf2 JB |
159 | } |
160 | ||
51798222 CH |
161 | static ssize_t simple_child_storeme_store(struct config_item *item, |
162 | const char *page, size_t count) | |
7063fbf2 JB |
163 | { |
164 | struct simple_child *simple_child = to_simple_child(item); | |
165 | unsigned long tmp; | |
166 | char *p = (char *) page; | |
167 | ||
168 | tmp = simple_strtoul(p, &p, 10); | |
169 | if (!p || (*p && (*p != '\n'))) | |
170 | return -EINVAL; | |
171 | ||
172 | if (tmp > INT_MAX) | |
173 | return -ERANGE; | |
174 | ||
175 | simple_child->storeme = tmp; | |
176 | ||
177 | return count; | |
178 | } | |
179 | ||
51798222 CH |
180 | CONFIGFS_ATTR(simple_child_, storeme); |
181 | ||
182 | static struct configfs_attribute *simple_child_attrs[] = { | |
183 | &simple_child_attr_storeme, | |
184 | NULL, | |
185 | }; | |
186 | ||
7063fbf2 JB |
187 | static void simple_child_release(struct config_item *item) |
188 | { | |
189 | kfree(to_simple_child(item)); | |
190 | } | |
191 | ||
192 | static struct configfs_item_operations simple_child_item_ops = { | |
193 | .release = simple_child_release, | |
7063fbf2 JB |
194 | }; |
195 | ||
196 | static struct config_item_type simple_child_type = { | |
197 | .ct_item_ops = &simple_child_item_ops, | |
198 | .ct_attrs = simple_child_attrs, | |
199 | .ct_owner = THIS_MODULE, | |
200 | }; | |
201 | ||
202 | ||
22dd0e88 JB |
203 | struct simple_children { |
204 | struct config_group group; | |
205 | }; | |
206 | ||
207 | static inline struct simple_children *to_simple_children(struct config_item *item) | |
208 | { | |
51798222 CH |
209 | return item ? container_of(to_config_group(item), |
210 | struct simple_children, group) : NULL; | |
22dd0e88 JB |
211 | } |
212 | ||
51798222 CH |
213 | static struct config_item *simple_children_make_item(struct config_group *group, |
214 | const char *name) | |
7063fbf2 JB |
215 | { |
216 | struct simple_child *simple_child; | |
217 | ||
dd00cc48 | 218 | simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL); |
7063fbf2 | 219 | if (!simple_child) |
a6795e9e | 220 | return ERR_PTR(-ENOMEM); |
7063fbf2 | 221 | |
7063fbf2 JB |
222 | config_item_init_type_name(&simple_child->item, name, |
223 | &simple_child_type); | |
224 | ||
225 | simple_child->storeme = 0; | |
226 | ||
f89ab861 | 227 | return &simple_child->item; |
7063fbf2 JB |
228 | } |
229 | ||
51798222 CH |
230 | static ssize_t simple_children_description_show(struct config_item *item, |
231 | char *page) | |
7063fbf2 JB |
232 | { |
233 | return sprintf(page, | |
234 | "[02-simple-children]\n" | |
235 | "\n" | |
236 | "This subsystem allows the creation of child config_items. These\n" | |
237 | "items have only one attribute that is readable and writeable.\n"); | |
238 | } | |
239 | ||
51798222 CH |
240 | CONFIGFS_ATTR_RO(simple_children_, description); |
241 | ||
242 | static struct configfs_attribute *simple_children_attrs[] = { | |
243 | &simple_children_attr_description, | |
244 | NULL, | |
245 | }; | |
246 | ||
22dd0e88 JB |
247 | static void simple_children_release(struct config_item *item) |
248 | { | |
249 | kfree(to_simple_children(item)); | |
250 | } | |
251 | ||
7063fbf2 | 252 | static struct configfs_item_operations simple_children_item_ops = { |
ecb3d28c | 253 | .release = simple_children_release, |
7063fbf2 JB |
254 | }; |
255 | ||
256 | /* | |
257 | * Note that, since no extra work is required on ->drop_item(), | |
258 | * no ->drop_item() is provided. | |
259 | */ | |
260 | static struct configfs_group_operations simple_children_group_ops = { | |
261 | .make_item = simple_children_make_item, | |
262 | }; | |
263 | ||
264 | static struct config_item_type simple_children_type = { | |
265 | .ct_item_ops = &simple_children_item_ops, | |
266 | .ct_group_ops = &simple_children_group_ops, | |
267 | .ct_attrs = simple_children_attrs, | |
3d0f89bb | 268 | .ct_owner = THIS_MODULE, |
7063fbf2 JB |
269 | }; |
270 | ||
271 | static struct configfs_subsystem simple_children_subsys = { | |
272 | .su_group = { | |
273 | .cg_item = { | |
274 | .ci_namebuf = "02-simple-children", | |
275 | .ci_type = &simple_children_type, | |
276 | }, | |
277 | }, | |
278 | }; | |
279 | ||
280 | ||
281 | /* ----------------------------------------------------------------- */ | |
282 | ||
283 | /* | |
284 | * 03-group-children | |
285 | * | |
286 | * This example reuses the simple_children group from above. However, | |
287 | * the simple_children group is not the subsystem itself, it is a | |
288 | * child of the subsystem. Creation of a group in the subsystem creates | |
289 | * a new simple_children group. That group can then have simple_child | |
290 | * children of its own. | |
291 | */ | |
292 | ||
51798222 CH |
293 | static struct config_group *group_children_make_group( |
294 | struct config_group *group, const char *name) | |
7063fbf2 JB |
295 | { |
296 | struct simple_children *simple_children; | |
297 | ||
dd00cc48 | 298 | simple_children = kzalloc(sizeof(struct simple_children), |
7063fbf2 JB |
299 | GFP_KERNEL); |
300 | if (!simple_children) | |
a6795e9e | 301 | return ERR_PTR(-ENOMEM); |
7063fbf2 | 302 | |
7063fbf2 JB |
303 | config_group_init_type_name(&simple_children->group, name, |
304 | &simple_children_type); | |
305 | ||
f89ab861 | 306 | return &simple_children->group; |
7063fbf2 JB |
307 | } |
308 | ||
51798222 CH |
309 | static ssize_t group_children_description_show(struct config_item *item, |
310 | char *page) | |
7063fbf2 JB |
311 | { |
312 | return sprintf(page, | |
313 | "[03-group-children]\n" | |
314 | "\n" | |
315 | "This subsystem allows the creation of child config_groups. These\n" | |
316 | "groups are like the subsystem simple-children.\n"); | |
317 | } | |
318 | ||
51798222 CH |
319 | CONFIGFS_ATTR_RO(group_children_, description); |
320 | ||
321 | static struct configfs_attribute *group_children_attrs[] = { | |
322 | &group_children_attr_description, | |
323 | NULL, | |
7063fbf2 JB |
324 | }; |
325 | ||
326 | /* | |
327 | * Note that, since no extra work is required on ->drop_item(), | |
328 | * no ->drop_item() is provided. | |
329 | */ | |
330 | static struct configfs_group_operations group_children_group_ops = { | |
331 | .make_group = group_children_make_group, | |
332 | }; | |
333 | ||
334 | static struct config_item_type group_children_type = { | |
7063fbf2 JB |
335 | .ct_group_ops = &group_children_group_ops, |
336 | .ct_attrs = group_children_attrs, | |
3d0f89bb | 337 | .ct_owner = THIS_MODULE, |
7063fbf2 JB |
338 | }; |
339 | ||
340 | static struct configfs_subsystem group_children_subsys = { | |
341 | .su_group = { | |
342 | .cg_item = { | |
343 | .ci_namebuf = "03-group-children", | |
344 | .ci_type = &group_children_type, | |
345 | }, | |
346 | }, | |
347 | }; | |
348 | ||
349 | /* ----------------------------------------------------------------- */ | |
350 | ||
351 | /* | |
352 | * We're now done with our subsystem definitions. | |
353 | * For convenience in this module, here's a list of them all. It | |
354 | * allows the init function to easily register them. Most modules | |
355 | * will only have one subsystem, and will only call register_subsystem | |
356 | * on it directly. | |
357 | */ | |
358 | static struct configfs_subsystem *example_subsys[] = { | |
359 | &childless_subsys.subsys, | |
360 | &simple_children_subsys, | |
361 | &group_children_subsys, | |
362 | NULL, | |
363 | }; | |
364 | ||
365 | static int __init configfs_example_init(void) | |
366 | { | |
367 | int ret; | |
368 | int i; | |
369 | struct configfs_subsystem *subsys; | |
370 | ||
371 | for (i = 0; example_subsys[i]; i++) { | |
372 | subsys = example_subsys[i]; | |
373 | ||
374 | config_group_init(&subsys->su_group); | |
e6bd07ae | 375 | mutex_init(&subsys->su_mutex); |
7063fbf2 JB |
376 | ret = configfs_register_subsystem(subsys); |
377 | if (ret) { | |
378 | printk(KERN_ERR "Error %d while registering subsystem %s\n", | |
379 | ret, | |
380 | subsys->su_group.cg_item.ci_namebuf); | |
381 | goto out_unregister; | |
382 | } | |
383 | } | |
384 | ||
385 | return 0; | |
386 | ||
387 | out_unregister: | |
dcb3a08e | 388 | for (i--; i >= 0; i--) |
7063fbf2 | 389 | configfs_unregister_subsystem(example_subsys[i]); |
7063fbf2 JB |
390 | |
391 | return ret; | |
392 | } | |
393 | ||
394 | static void __exit configfs_example_exit(void) | |
395 | { | |
396 | int i; | |
397 | ||
dcb3a08e | 398 | for (i = 0; example_subsys[i]; i++) |
7063fbf2 | 399 | configfs_unregister_subsystem(example_subsys[i]); |
7063fbf2 JB |
400 | } |
401 | ||
402 | module_init(configfs_example_init); | |
403 | module_exit(configfs_example_exit); | |
404 | MODULE_LICENSE("GPL"); |