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1 | /* | |
2 | * kobject.c - library routines for handling generic kernel objects | |
3 | * | |
4 | * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org> | |
5 | * Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com> | |
6 | * Copyright (c) 2006-2007 Novell Inc. | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | * | |
10 | * | |
11 | * Please see the file Documentation/kobject.txt for critical information | |
12 | * about using the kobject interface. | |
13 | */ | |
14 | ||
15 | #include <linux/kobject.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/stat.h> | |
19 | #include <linux/slab.h> | |
20 | ||
21 | /* | |
22 | * populate_dir - populate directory with attributes. | |
23 | * @kobj: object we're working on. | |
24 | * | |
25 | * Most subsystems have a set of default attributes that are associated | |
26 | * with an object that registers with them. This is a helper called during | |
27 | * object registration that loops through the default attributes of the | |
28 | * subsystem and creates attributes files for them in sysfs. | |
29 | */ | |
30 | static int populate_dir(struct kobject *kobj) | |
31 | { | |
32 | struct kobj_type *t = get_ktype(kobj); | |
33 | struct attribute *attr; | |
34 | int error = 0; | |
35 | int i; | |
36 | ||
37 | if (t && t->default_attrs) { | |
38 | for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) { | |
39 | error = sysfs_create_file(kobj, attr); | |
40 | if (error) | |
41 | break; | |
42 | } | |
43 | } | |
44 | return error; | |
45 | } | |
46 | ||
47 | static int create_dir(struct kobject *kobj) | |
48 | { | |
49 | int error = 0; | |
50 | if (kobject_name(kobj)) { | |
51 | error = sysfs_create_dir(kobj); | |
52 | if (!error) { | |
53 | error = populate_dir(kobj); | |
54 | if (error) | |
55 | sysfs_remove_dir(kobj); | |
56 | } | |
57 | } | |
58 | return error; | |
59 | } | |
60 | ||
61 | static int get_kobj_path_length(struct kobject *kobj) | |
62 | { | |
63 | int length = 1; | |
64 | struct kobject *parent = kobj; | |
65 | ||
66 | /* walk up the ancestors until we hit the one pointing to the | |
67 | * root. | |
68 | * Add 1 to strlen for leading '/' of each level. | |
69 | */ | |
70 | do { | |
71 | if (kobject_name(parent) == NULL) | |
72 | return 0; | |
73 | length += strlen(kobject_name(parent)) + 1; | |
74 | parent = parent->parent; | |
75 | } while (parent); | |
76 | return length; | |
77 | } | |
78 | ||
79 | static void fill_kobj_path(struct kobject *kobj, char *path, int length) | |
80 | { | |
81 | struct kobject *parent; | |
82 | ||
83 | --length; | |
84 | for (parent = kobj; parent; parent = parent->parent) { | |
85 | int cur = strlen(kobject_name(parent)); | |
86 | /* back up enough to print this name with '/' */ | |
87 | length -= cur; | |
88 | strncpy(path + length, kobject_name(parent), cur); | |
89 | *(path + --length) = '/'; | |
90 | } | |
91 | ||
92 | pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj), | |
93 | kobj, __func__, path); | |
94 | } | |
95 | ||
96 | /** | |
97 | * kobject_get_path - generate and return the path associated with a given kobj and kset pair. | |
98 | * | |
99 | * @kobj: kobject in question, with which to build the path | |
100 | * @gfp_mask: the allocation type used to allocate the path | |
101 | * | |
102 | * The result must be freed by the caller with kfree(). | |
103 | */ | |
104 | char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask) | |
105 | { | |
106 | char *path; | |
107 | int len; | |
108 | ||
109 | len = get_kobj_path_length(kobj); | |
110 | if (len == 0) | |
111 | return NULL; | |
112 | path = kzalloc(len, gfp_mask); | |
113 | if (!path) | |
114 | return NULL; | |
115 | fill_kobj_path(kobj, path, len); | |
116 | ||
117 | return path; | |
118 | } | |
119 | EXPORT_SYMBOL_GPL(kobject_get_path); | |
120 | ||
121 | /* add the kobject to its kset's list */ | |
122 | static void kobj_kset_join(struct kobject *kobj) | |
123 | { | |
124 | if (!kobj->kset) | |
125 | return; | |
126 | ||
127 | kset_get(kobj->kset); | |
128 | spin_lock(&kobj->kset->list_lock); | |
129 | list_add_tail(&kobj->entry, &kobj->kset->list); | |
130 | spin_unlock(&kobj->kset->list_lock); | |
131 | } | |
132 | ||
133 | /* remove the kobject from its kset's list */ | |
134 | static void kobj_kset_leave(struct kobject *kobj) | |
135 | { | |
136 | if (!kobj->kset) | |
137 | return; | |
138 | ||
139 | spin_lock(&kobj->kset->list_lock); | |
140 | list_del_init(&kobj->entry); | |
141 | spin_unlock(&kobj->kset->list_lock); | |
142 | kset_put(kobj->kset); | |
143 | } | |
144 | ||
145 | static void kobject_init_internal(struct kobject *kobj) | |
146 | { | |
147 | if (!kobj) | |
148 | return; | |
149 | kref_init(&kobj->kref); | |
150 | INIT_LIST_HEAD(&kobj->entry); | |
151 | kobj->state_in_sysfs = 0; | |
152 | kobj->state_add_uevent_sent = 0; | |
153 | kobj->state_remove_uevent_sent = 0; | |
154 | kobj->state_initialized = 1; | |
155 | } | |
156 | ||
157 | ||
158 | static int kobject_add_internal(struct kobject *kobj) | |
159 | { | |
160 | int error = 0; | |
161 | struct kobject *parent; | |
162 | ||
163 | if (!kobj) | |
164 | return -ENOENT; | |
165 | ||
166 | if (!kobj->name || !kobj->name[0]) { | |
167 | pr_debug("kobject: (%p): attempted to be registered with empty " | |
168 | "name!\n", kobj); | |
169 | WARN_ON(1); | |
170 | return -EINVAL; | |
171 | } | |
172 | ||
173 | parent = kobject_get(kobj->parent); | |
174 | ||
175 | /* join kset if set, use it as parent if we do not already have one */ | |
176 | if (kobj->kset) { | |
177 | if (!parent) | |
178 | parent = kobject_get(&kobj->kset->kobj); | |
179 | kobj_kset_join(kobj); | |
180 | kobj->parent = parent; | |
181 | } | |
182 | ||
183 | pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n", | |
184 | kobject_name(kobj), kobj, __func__, | |
185 | parent ? kobject_name(parent) : "<NULL>", | |
186 | kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>"); | |
187 | ||
188 | error = create_dir(kobj); | |
189 | if (error) { | |
190 | kobj_kset_leave(kobj); | |
191 | kobject_put(parent); | |
192 | kobj->parent = NULL; | |
193 | ||
194 | /* be noisy on error issues */ | |
195 | if (error == -EEXIST) | |
196 | printk(KERN_ERR "%s failed for %s with " | |
197 | "-EEXIST, don't try to register things with " | |
198 | "the same name in the same directory.\n", | |
199 | __func__, kobject_name(kobj)); | |
200 | else | |
201 | printk(KERN_ERR "%s failed for %s (%d)\n", | |
202 | __func__, kobject_name(kobj), error); | |
203 | dump_stack(); | |
204 | } else | |
205 | kobj->state_in_sysfs = 1; | |
206 | ||
207 | return error; | |
208 | } | |
209 | ||
210 | /** | |
211 | * kobject_set_name_vargs - Set the name of an kobject | |
212 | * @kobj: struct kobject to set the name of | |
213 | * @fmt: format string used to build the name | |
214 | * @vargs: vargs to format the string. | |
215 | */ | |
216 | static int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, | |
217 | va_list vargs) | |
218 | { | |
219 | /* Free the old name, if necessary. */ | |
220 | kfree(kobj->name); | |
221 | ||
222 | kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); | |
223 | if (!kobj->name) | |
224 | return -ENOMEM; | |
225 | ||
226 | return 0; | |
227 | } | |
228 | ||
229 | /** | |
230 | * kobject_set_name - Set the name of a kobject | |
231 | * @kobj: struct kobject to set the name of | |
232 | * @fmt: format string used to build the name | |
233 | * | |
234 | * This sets the name of the kobject. If you have already added the | |
235 | * kobject to the system, you must call kobject_rename() in order to | |
236 | * change the name of the kobject. | |
237 | */ | |
238 | int kobject_set_name(struct kobject *kobj, const char *fmt, ...) | |
239 | { | |
240 | va_list vargs; | |
241 | int retval; | |
242 | ||
243 | va_start(vargs, fmt); | |
244 | retval = kobject_set_name_vargs(kobj, fmt, vargs); | |
245 | va_end(vargs); | |
246 | ||
247 | return retval; | |
248 | } | |
249 | EXPORT_SYMBOL(kobject_set_name); | |
250 | ||
251 | /** | |
252 | * kobject_init - initialize a kobject structure | |
253 | * @kobj: pointer to the kobject to initialize | |
254 | * @ktype: pointer to the ktype for this kobject. | |
255 | * | |
256 | * This function will properly initialize a kobject such that it can then | |
257 | * be passed to the kobject_add() call. | |
258 | * | |
259 | * After this function is called, the kobject MUST be cleaned up by a call | |
260 | * to kobject_put(), not by a call to kfree directly to ensure that all of | |
261 | * the memory is cleaned up properly. | |
262 | */ | |
263 | void kobject_init(struct kobject *kobj, struct kobj_type *ktype) | |
264 | { | |
265 | char *err_str; | |
266 | ||
267 | if (!kobj) { | |
268 | err_str = "invalid kobject pointer!"; | |
269 | goto error; | |
270 | } | |
271 | if (!ktype) { | |
272 | err_str = "must have a ktype to be initialized properly!\n"; | |
273 | goto error; | |
274 | } | |
275 | if (kobj->state_initialized) { | |
276 | /* do not error out as sometimes we can recover */ | |
277 | printk(KERN_ERR "kobject (%p): tried to init an initialized " | |
278 | "object, something is seriously wrong.\n", kobj); | |
279 | dump_stack(); | |
280 | } | |
281 | ||
282 | kobject_init_internal(kobj); | |
283 | kobj->ktype = ktype; | |
284 | return; | |
285 | ||
286 | error: | |
287 | printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str); | |
288 | dump_stack(); | |
289 | } | |
290 | EXPORT_SYMBOL(kobject_init); | |
291 | ||
292 | static int kobject_add_varg(struct kobject *kobj, struct kobject *parent, | |
293 | const char *fmt, va_list vargs) | |
294 | { | |
295 | int retval; | |
296 | ||
297 | retval = kobject_set_name_vargs(kobj, fmt, vargs); | |
298 | if (retval) { | |
299 | printk(KERN_ERR "kobject: can not set name properly!\n"); | |
300 | return retval; | |
301 | } | |
302 | kobj->parent = parent; | |
303 | return kobject_add_internal(kobj); | |
304 | } | |
305 | ||
306 | /** | |
307 | * kobject_add - the main kobject add function | |
308 | * @kobj: the kobject to add | |
309 | * @parent: pointer to the parent of the kobject. | |
310 | * @fmt: format to name the kobject with. | |
311 | * | |
312 | * The kobject name is set and added to the kobject hierarchy in this | |
313 | * function. | |
314 | * | |
315 | * If @parent is set, then the parent of the @kobj will be set to it. | |
316 | * If @parent is NULL, then the parent of the @kobj will be set to the | |
317 | * kobject associted with the kset assigned to this kobject. If no kset | |
318 | * is assigned to the kobject, then the kobject will be located in the | |
319 | * root of the sysfs tree. | |
320 | * | |
321 | * If this function returns an error, kobject_put() must be called to | |
322 | * properly clean up the memory associated with the object. | |
323 | * Under no instance should the kobject that is passed to this function | |
324 | * be directly freed with a call to kfree(), that can leak memory. | |
325 | * | |
326 | * Note, no "add" uevent will be created with this call, the caller should set | |
327 | * up all of the necessary sysfs files for the object and then call | |
328 | * kobject_uevent() with the UEVENT_ADD parameter to ensure that | |
329 | * userspace is properly notified of this kobject's creation. | |
330 | */ | |
331 | int kobject_add(struct kobject *kobj, struct kobject *parent, | |
332 | const char *fmt, ...) | |
333 | { | |
334 | va_list args; | |
335 | int retval; | |
336 | ||
337 | if (!kobj) | |
338 | return -EINVAL; | |
339 | ||
340 | if (!kobj->state_initialized) { | |
341 | printk(KERN_ERR "kobject '%s' (%p): tried to add an " | |
342 | "uninitialized object, something is seriously wrong.\n", | |
343 | kobject_name(kobj), kobj); | |
344 | dump_stack(); | |
345 | return -EINVAL; | |
346 | } | |
347 | va_start(args, fmt); | |
348 | retval = kobject_add_varg(kobj, parent, fmt, args); | |
349 | va_end(args); | |
350 | ||
351 | return retval; | |
352 | } | |
353 | EXPORT_SYMBOL(kobject_add); | |
354 | ||
355 | /** | |
356 | * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy | |
357 | * @kobj: pointer to the kobject to initialize | |
358 | * @ktype: pointer to the ktype for this kobject. | |
359 | * @parent: pointer to the parent of this kobject. | |
360 | * @fmt: the name of the kobject. | |
361 | * | |
362 | * This function combines the call to kobject_init() and | |
363 | * kobject_add(). The same type of error handling after a call to | |
364 | * kobject_add() and kobject lifetime rules are the same here. | |
365 | */ | |
366 | int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype, | |
367 | struct kobject *parent, const char *fmt, ...) | |
368 | { | |
369 | va_list args; | |
370 | int retval; | |
371 | ||
372 | kobject_init(kobj, ktype); | |
373 | ||
374 | va_start(args, fmt); | |
375 | retval = kobject_add_varg(kobj, parent, fmt, args); | |
376 | va_end(args); | |
377 | ||
378 | return retval; | |
379 | } | |
380 | EXPORT_SYMBOL_GPL(kobject_init_and_add); | |
381 | ||
382 | /** | |
383 | * kobject_rename - change the name of an object | |
384 | * @kobj: object in question. | |
385 | * @new_name: object's new name | |
386 | */ | |
387 | int kobject_rename(struct kobject *kobj, const char *new_name) | |
388 | { | |
389 | int error = 0; | |
390 | const char *devpath = NULL; | |
391 | char *devpath_string = NULL; | |
392 | char *envp[2]; | |
393 | ||
394 | kobj = kobject_get(kobj); | |
395 | if (!kobj) | |
396 | return -EINVAL; | |
397 | if (!kobj->parent) | |
398 | return -EINVAL; | |
399 | ||
400 | /* see if this name is already in use */ | |
401 | if (kobj->kset) { | |
402 | struct kobject *temp_kobj; | |
403 | temp_kobj = kset_find_obj(kobj->kset, new_name); | |
404 | if (temp_kobj) { | |
405 | printk(KERN_WARNING "kobject '%s' cannot be renamed " | |
406 | "to '%s' as '%s' is already in existence.\n", | |
407 | kobject_name(kobj), new_name, new_name); | |
408 | kobject_put(temp_kobj); | |
409 | return -EINVAL; | |
410 | } | |
411 | } | |
412 | ||
413 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
414 | if (!devpath) { | |
415 | error = -ENOMEM; | |
416 | goto out; | |
417 | } | |
418 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); | |
419 | if (!devpath_string) { | |
420 | error = -ENOMEM; | |
421 | goto out; | |
422 | } | |
423 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); | |
424 | envp[0] = devpath_string; | |
425 | envp[1] = NULL; | |
426 | ||
427 | error = sysfs_rename_dir(kobj, new_name); | |
428 | ||
429 | /* This function is mostly/only used for network interface. | |
430 | * Some hotplug package track interfaces by their name and | |
431 | * therefore want to know when the name is changed by the user. */ | |
432 | if (!error) | |
433 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); | |
434 | ||
435 | out: | |
436 | kfree(devpath_string); | |
437 | kfree(devpath); | |
438 | kobject_put(kobj); | |
439 | ||
440 | return error; | |
441 | } | |
442 | EXPORT_SYMBOL_GPL(kobject_rename); | |
443 | ||
444 | /** | |
445 | * kobject_move - move object to another parent | |
446 | * @kobj: object in question. | |
447 | * @new_parent: object's new parent (can be NULL) | |
448 | */ | |
449 | int kobject_move(struct kobject *kobj, struct kobject *new_parent) | |
450 | { | |
451 | int error; | |
452 | struct kobject *old_parent; | |
453 | const char *devpath = NULL; | |
454 | char *devpath_string = NULL; | |
455 | char *envp[2]; | |
456 | ||
457 | kobj = kobject_get(kobj); | |
458 | if (!kobj) | |
459 | return -EINVAL; | |
460 | new_parent = kobject_get(new_parent); | |
461 | if (!new_parent) { | |
462 | if (kobj->kset) | |
463 | new_parent = kobject_get(&kobj->kset->kobj); | |
464 | } | |
465 | /* old object path */ | |
466 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
467 | if (!devpath) { | |
468 | error = -ENOMEM; | |
469 | goto out; | |
470 | } | |
471 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); | |
472 | if (!devpath_string) { | |
473 | error = -ENOMEM; | |
474 | goto out; | |
475 | } | |
476 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); | |
477 | envp[0] = devpath_string; | |
478 | envp[1] = NULL; | |
479 | error = sysfs_move_dir(kobj, new_parent); | |
480 | if (error) | |
481 | goto out; | |
482 | old_parent = kobj->parent; | |
483 | kobj->parent = new_parent; | |
484 | new_parent = NULL; | |
485 | kobject_put(old_parent); | |
486 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); | |
487 | out: | |
488 | kobject_put(new_parent); | |
489 | kobject_put(kobj); | |
490 | kfree(devpath_string); | |
491 | kfree(devpath); | |
492 | return error; | |
493 | } | |
494 | ||
495 | /** | |
496 | * kobject_del - unlink kobject from hierarchy. | |
497 | * @kobj: object. | |
498 | */ | |
499 | void kobject_del(struct kobject *kobj) | |
500 | { | |
501 | if (!kobj) | |
502 | return; | |
503 | ||
504 | sysfs_remove_dir(kobj); | |
505 | kobj->state_in_sysfs = 0; | |
506 | kobj_kset_leave(kobj); | |
507 | kobject_put(kobj->parent); | |
508 | kobj->parent = NULL; | |
509 | } | |
510 | ||
511 | /** | |
512 | * kobject_get - increment refcount for object. | |
513 | * @kobj: object. | |
514 | */ | |
515 | struct kobject *kobject_get(struct kobject *kobj) | |
516 | { | |
517 | if (kobj) | |
518 | kref_get(&kobj->kref); | |
519 | return kobj; | |
520 | } | |
521 | ||
522 | /* | |
523 | * kobject_cleanup - free kobject resources. | |
524 | * @kobj: object to cleanup | |
525 | */ | |
526 | static void kobject_cleanup(struct kobject *kobj) | |
527 | { | |
528 | struct kobj_type *t = get_ktype(kobj); | |
529 | const char *name = kobj->name; | |
530 | ||
531 | pr_debug("kobject: '%s' (%p): %s\n", | |
532 | kobject_name(kobj), kobj, __func__); | |
533 | ||
534 | if (t && !t->release) | |
535 | pr_debug("kobject: '%s' (%p): does not have a release() " | |
536 | "function, it is broken and must be fixed.\n", | |
537 | kobject_name(kobj), kobj); | |
538 | ||
539 | /* send "remove" if the caller did not do it but sent "add" */ | |
540 | if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) { | |
541 | pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n", | |
542 | kobject_name(kobj), kobj); | |
543 | kobject_uevent(kobj, KOBJ_REMOVE); | |
544 | } | |
545 | ||
546 | /* remove from sysfs if the caller did not do it */ | |
547 | if (kobj->state_in_sysfs) { | |
548 | pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n", | |
549 | kobject_name(kobj), kobj); | |
550 | kobject_del(kobj); | |
551 | } | |
552 | ||
553 | if (t && t->release) { | |
554 | pr_debug("kobject: '%s' (%p): calling ktype release\n", | |
555 | kobject_name(kobj), kobj); | |
556 | t->release(kobj); | |
557 | } | |
558 | ||
559 | /* free name if we allocated it */ | |
560 | if (name) { | |
561 | pr_debug("kobject: '%s': free name\n", name); | |
562 | kfree(name); | |
563 | } | |
564 | } | |
565 | ||
566 | static void kobject_release(struct kref *kref) | |
567 | { | |
568 | kobject_cleanup(container_of(kref, struct kobject, kref)); | |
569 | } | |
570 | ||
571 | /** | |
572 | * kobject_put - decrement refcount for object. | |
573 | * @kobj: object. | |
574 | * | |
575 | * Decrement the refcount, and if 0, call kobject_cleanup(). | |
576 | */ | |
577 | void kobject_put(struct kobject *kobj) | |
578 | { | |
579 | if (kobj) { | |
580 | if (!kobj->state_initialized) { | |
581 | printk(KERN_WARNING "kobject: '%s' (%p): is not " | |
582 | "initialized, yet kobject_put() is being " | |
583 | "called.\n", kobject_name(kobj), kobj); | |
584 | WARN_ON(1); | |
585 | } | |
586 | kref_put(&kobj->kref, kobject_release); | |
587 | } | |
588 | } | |
589 | ||
590 | static void dynamic_kobj_release(struct kobject *kobj) | |
591 | { | |
592 | pr_debug("kobject: (%p): %s\n", kobj, __func__); | |
593 | kfree(kobj); | |
594 | } | |
595 | ||
596 | static struct kobj_type dynamic_kobj_ktype = { | |
597 | .release = dynamic_kobj_release, | |
598 | .sysfs_ops = &kobj_sysfs_ops, | |
599 | }; | |
600 | ||
601 | /** | |
602 | * kobject_create - create a struct kobject dynamically | |
603 | * | |
604 | * This function creates a kobject structure dynamically and sets it up | |
605 | * to be a "dynamic" kobject with a default release function set up. | |
606 | * | |
607 | * If the kobject was not able to be created, NULL will be returned. | |
608 | * The kobject structure returned from here must be cleaned up with a | |
609 | * call to kobject_put() and not kfree(), as kobject_init() has | |
610 | * already been called on this structure. | |
611 | */ | |
612 | struct kobject *kobject_create(void) | |
613 | { | |
614 | struct kobject *kobj; | |
615 | ||
616 | kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); | |
617 | if (!kobj) | |
618 | return NULL; | |
619 | ||
620 | kobject_init(kobj, &dynamic_kobj_ktype); | |
621 | return kobj; | |
622 | } | |
623 | ||
624 | /** | |
625 | * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs | |
626 | * | |
627 | * @name: the name for the kset | |
628 | * @parent: the parent kobject of this kobject, if any. | |
629 | * | |
630 | * This function creates a kobject structure dynamically and registers it | |
631 | * with sysfs. When you are finished with this structure, call | |
632 | * kobject_put() and the structure will be dynamically freed when | |
633 | * it is no longer being used. | |
634 | * | |
635 | * If the kobject was not able to be created, NULL will be returned. | |
636 | */ | |
637 | struct kobject *kobject_create_and_add(const char *name, struct kobject *parent) | |
638 | { | |
639 | struct kobject *kobj; | |
640 | int retval; | |
641 | ||
642 | kobj = kobject_create(); | |
643 | if (!kobj) | |
644 | return NULL; | |
645 | ||
646 | retval = kobject_add(kobj, parent, "%s", name); | |
647 | if (retval) { | |
648 | printk(KERN_WARNING "%s: kobject_add error: %d\n", | |
649 | __func__, retval); | |
650 | kobject_put(kobj); | |
651 | kobj = NULL; | |
652 | } | |
653 | return kobj; | |
654 | } | |
655 | EXPORT_SYMBOL_GPL(kobject_create_and_add); | |
656 | ||
657 | /** | |
658 | * kset_init - initialize a kset for use | |
659 | * @k: kset | |
660 | */ | |
661 | void kset_init(struct kset *k) | |
662 | { | |
663 | kobject_init_internal(&k->kobj); | |
664 | INIT_LIST_HEAD(&k->list); | |
665 | spin_lock_init(&k->list_lock); | |
666 | } | |
667 | ||
668 | /* default kobject attribute operations */ | |
669 | static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr, | |
670 | char *buf) | |
671 | { | |
672 | struct kobj_attribute *kattr; | |
673 | ssize_t ret = -EIO; | |
674 | ||
675 | kattr = container_of(attr, struct kobj_attribute, attr); | |
676 | if (kattr->show) | |
677 | ret = kattr->show(kobj, kattr, buf); | |
678 | return ret; | |
679 | } | |
680 | ||
681 | static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr, | |
682 | const char *buf, size_t count) | |
683 | { | |
684 | struct kobj_attribute *kattr; | |
685 | ssize_t ret = -EIO; | |
686 | ||
687 | kattr = container_of(attr, struct kobj_attribute, attr); | |
688 | if (kattr->store) | |
689 | ret = kattr->store(kobj, kattr, buf, count); | |
690 | return ret; | |
691 | } | |
692 | ||
693 | struct sysfs_ops kobj_sysfs_ops = { | |
694 | .show = kobj_attr_show, | |
695 | .store = kobj_attr_store, | |
696 | }; | |
697 | ||
698 | /** | |
699 | * kset_register - initialize and add a kset. | |
700 | * @k: kset. | |
701 | */ | |
702 | int kset_register(struct kset *k) | |
703 | { | |
704 | int err; | |
705 | ||
706 | if (!k) | |
707 | return -EINVAL; | |
708 | ||
709 | kset_init(k); | |
710 | err = kobject_add_internal(&k->kobj); | |
711 | if (err) | |
712 | return err; | |
713 | kobject_uevent(&k->kobj, KOBJ_ADD); | |
714 | return 0; | |
715 | } | |
716 | ||
717 | /** | |
718 | * kset_unregister - remove a kset. | |
719 | * @k: kset. | |
720 | */ | |
721 | void kset_unregister(struct kset *k) | |
722 | { | |
723 | if (!k) | |
724 | return; | |
725 | kobject_put(&k->kobj); | |
726 | } | |
727 | ||
728 | /** | |
729 | * kset_find_obj - search for object in kset. | |
730 | * @kset: kset we're looking in. | |
731 | * @name: object's name. | |
732 | * | |
733 | * Lock kset via @kset->subsys, and iterate over @kset->list, | |
734 | * looking for a matching kobject. If matching object is found | |
735 | * take a reference and return the object. | |
736 | */ | |
737 | struct kobject *kset_find_obj(struct kset *kset, const char *name) | |
738 | { | |
739 | struct kobject *k; | |
740 | struct kobject *ret = NULL; | |
741 | ||
742 | spin_lock(&kset->list_lock); | |
743 | list_for_each_entry(k, &kset->list, entry) { | |
744 | if (kobject_name(k) && !strcmp(kobject_name(k), name)) { | |
745 | ret = kobject_get(k); | |
746 | break; | |
747 | } | |
748 | } | |
749 | spin_unlock(&kset->list_lock); | |
750 | return ret; | |
751 | } | |
752 | ||
753 | static void kset_release(struct kobject *kobj) | |
754 | { | |
755 | struct kset *kset = container_of(kobj, struct kset, kobj); | |
756 | pr_debug("kobject: '%s' (%p): %s\n", | |
757 | kobject_name(kobj), kobj, __func__); | |
758 | kfree(kset); | |
759 | } | |
760 | ||
761 | static struct kobj_type kset_ktype = { | |
762 | .sysfs_ops = &kobj_sysfs_ops, | |
763 | .release = kset_release, | |
764 | }; | |
765 | ||
766 | /** | |
767 | * kset_create - create a struct kset dynamically | |
768 | * | |
769 | * @name: the name for the kset | |
770 | * @uevent_ops: a struct kset_uevent_ops for the kset | |
771 | * @parent_kobj: the parent kobject of this kset, if any. | |
772 | * | |
773 | * This function creates a kset structure dynamically. This structure can | |
774 | * then be registered with the system and show up in sysfs with a call to | |
775 | * kset_register(). When you are finished with this structure, if | |
776 | * kset_register() has been called, call kset_unregister() and the | |
777 | * structure will be dynamically freed when it is no longer being used. | |
778 | * | |
779 | * If the kset was not able to be created, NULL will be returned. | |
780 | */ | |
781 | static struct kset *kset_create(const char *name, | |
782 | struct kset_uevent_ops *uevent_ops, | |
783 | struct kobject *parent_kobj) | |
784 | { | |
785 | struct kset *kset; | |
786 | ||
787 | kset = kzalloc(sizeof(*kset), GFP_KERNEL); | |
788 | if (!kset) | |
789 | return NULL; | |
790 | kobject_set_name(&kset->kobj, name); | |
791 | kset->uevent_ops = uevent_ops; | |
792 | kset->kobj.parent = parent_kobj; | |
793 | ||
794 | /* | |
795 | * The kobject of this kset will have a type of kset_ktype and belong to | |
796 | * no kset itself. That way we can properly free it when it is | |
797 | * finished being used. | |
798 | */ | |
799 | kset->kobj.ktype = &kset_ktype; | |
800 | kset->kobj.kset = NULL; | |
801 | ||
802 | return kset; | |
803 | } | |
804 | ||
805 | /** | |
806 | * kset_create_and_add - create a struct kset dynamically and add it to sysfs | |
807 | * | |
808 | * @name: the name for the kset | |
809 | * @uevent_ops: a struct kset_uevent_ops for the kset | |
810 | * @parent_kobj: the parent kobject of this kset, if any. | |
811 | * | |
812 | * This function creates a kset structure dynamically and registers it | |
813 | * with sysfs. When you are finished with this structure, call | |
814 | * kset_unregister() and the structure will be dynamically freed when it | |
815 | * is no longer being used. | |
816 | * | |
817 | * If the kset was not able to be created, NULL will be returned. | |
818 | */ | |
819 | struct kset *kset_create_and_add(const char *name, | |
820 | struct kset_uevent_ops *uevent_ops, | |
821 | struct kobject *parent_kobj) | |
822 | { | |
823 | struct kset *kset; | |
824 | int error; | |
825 | ||
826 | kset = kset_create(name, uevent_ops, parent_kobj); | |
827 | if (!kset) | |
828 | return NULL; | |
829 | error = kset_register(kset); | |
830 | if (error) { | |
831 | kfree(kset); | |
832 | return NULL; | |
833 | } | |
834 | return kset; | |
835 | } | |
836 | EXPORT_SYMBOL_GPL(kset_create_and_add); | |
837 | ||
838 | EXPORT_SYMBOL(kobject_get); | |
839 | EXPORT_SYMBOL(kobject_put); | |
840 | EXPORT_SYMBOL(kobject_del); | |
841 | ||
842 | EXPORT_SYMBOL(kset_register); | |
843 | EXPORT_SYMBOL(kset_unregister); |