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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/kobj_completion.h> | |
17 | #include <linux/string.h> | |
18 | #include <linux/export.h> | |
19 | #include <linux/stat.h> | |
20 | #include <linux/slab.h> | |
21 | ||
22 | /** | |
23 | * kobject_namespace - return @kobj's namespace tag | |
24 | * @kobj: kobject in question | |
25 | * | |
26 | * Returns namespace tag of @kobj if its parent has namespace ops enabled | |
27 | * and thus @kobj should have a namespace tag associated with it. Returns | |
28 | * %NULL otherwise. | |
29 | */ | |
30 | const void *kobject_namespace(struct kobject *kobj) | |
31 | { | |
32 | const struct kobj_ns_type_operations *ns_ops = kobj_ns_ops(kobj); | |
33 | const void *ns; | |
34 | ||
35 | if (!ns_ops || ns_ops->type == KOBJ_NS_TYPE_NONE) | |
36 | return NULL; | |
37 | ||
38 | ns = kobj->ktype->namespace(kobj); | |
39 | WARN_ON(!ns); /* @kobj in a namespace is required to have !NULL tag */ | |
40 | return ns; | |
41 | } | |
42 | ||
43 | /* | |
44 | * populate_dir - populate directory with attributes. | |
45 | * @kobj: object we're working on. | |
46 | * | |
47 | * Most subsystems have a set of default attributes that are associated | |
48 | * with an object that registers with them. This is a helper called during | |
49 | * object registration that loops through the default attributes of the | |
50 | * subsystem and creates attributes files for them in sysfs. | |
51 | */ | |
52 | static int populate_dir(struct kobject *kobj) | |
53 | { | |
54 | struct kobj_type *t = get_ktype(kobj); | |
55 | struct attribute *attr; | |
56 | int error = 0; | |
57 | int i; | |
58 | ||
59 | if (t && t->default_attrs) { | |
60 | for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) { | |
61 | error = sysfs_create_file(kobj, attr); | |
62 | if (error) | |
63 | break; | |
64 | } | |
65 | } | |
66 | return error; | |
67 | } | |
68 | ||
69 | static int create_dir(struct kobject *kobj) | |
70 | { | |
71 | int error; | |
72 | ||
73 | error = sysfs_create_dir_ns(kobj, kobject_namespace(kobj)); | |
74 | if (!error) { | |
75 | error = populate_dir(kobj); | |
76 | if (error) | |
77 | sysfs_remove_dir(kobj); | |
78 | } | |
79 | ||
80 | /* | |
81 | * @kobj->sd may be deleted by an ancestor going away. Hold an | |
82 | * extra reference so that it stays until @kobj is gone. | |
83 | */ | |
84 | sysfs_get(kobj->sd); | |
85 | ||
86 | return error; | |
87 | } | |
88 | ||
89 | static int get_kobj_path_length(struct kobject *kobj) | |
90 | { | |
91 | int length = 1; | |
92 | struct kobject *parent = kobj; | |
93 | ||
94 | /* walk up the ancestors until we hit the one pointing to the | |
95 | * root. | |
96 | * Add 1 to strlen for leading '/' of each level. | |
97 | */ | |
98 | do { | |
99 | if (kobject_name(parent) == NULL) | |
100 | return 0; | |
101 | length += strlen(kobject_name(parent)) + 1; | |
102 | parent = parent->parent; | |
103 | } while (parent); | |
104 | return length; | |
105 | } | |
106 | ||
107 | static void fill_kobj_path(struct kobject *kobj, char *path, int length) | |
108 | { | |
109 | struct kobject *parent; | |
110 | ||
111 | --length; | |
112 | for (parent = kobj; parent; parent = parent->parent) { | |
113 | int cur = strlen(kobject_name(parent)); | |
114 | /* back up enough to print this name with '/' */ | |
115 | length -= cur; | |
116 | strncpy(path + length, kobject_name(parent), cur); | |
117 | *(path + --length) = '/'; | |
118 | } | |
119 | ||
120 | pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj), | |
121 | kobj, __func__, path); | |
122 | } | |
123 | ||
124 | /** | |
125 | * kobject_get_path - generate and return the path associated with a given kobj and kset pair. | |
126 | * | |
127 | * @kobj: kobject in question, with which to build the path | |
128 | * @gfp_mask: the allocation type used to allocate the path | |
129 | * | |
130 | * The result must be freed by the caller with kfree(). | |
131 | */ | |
132 | char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask) | |
133 | { | |
134 | char *path; | |
135 | int len; | |
136 | ||
137 | len = get_kobj_path_length(kobj); | |
138 | if (len == 0) | |
139 | return NULL; | |
140 | path = kzalloc(len, gfp_mask); | |
141 | if (!path) | |
142 | return NULL; | |
143 | fill_kobj_path(kobj, path, len); | |
144 | ||
145 | return path; | |
146 | } | |
147 | EXPORT_SYMBOL_GPL(kobject_get_path); | |
148 | ||
149 | /* add the kobject to its kset's list */ | |
150 | static void kobj_kset_join(struct kobject *kobj) | |
151 | { | |
152 | if (!kobj->kset) | |
153 | return; | |
154 | ||
155 | kset_get(kobj->kset); | |
156 | spin_lock(&kobj->kset->list_lock); | |
157 | list_add_tail(&kobj->entry, &kobj->kset->list); | |
158 | spin_unlock(&kobj->kset->list_lock); | |
159 | } | |
160 | ||
161 | /* remove the kobject from its kset's list */ | |
162 | static void kobj_kset_leave(struct kobject *kobj) | |
163 | { | |
164 | if (!kobj->kset) | |
165 | return; | |
166 | ||
167 | spin_lock(&kobj->kset->list_lock); | |
168 | list_del_init(&kobj->entry); | |
169 | spin_unlock(&kobj->kset->list_lock); | |
170 | kset_put(kobj->kset); | |
171 | } | |
172 | ||
173 | static void kobject_init_internal(struct kobject *kobj) | |
174 | { | |
175 | if (!kobj) | |
176 | return; | |
177 | kref_init(&kobj->kref); | |
178 | INIT_LIST_HEAD(&kobj->entry); | |
179 | kobj->state_in_sysfs = 0; | |
180 | kobj->state_add_uevent_sent = 0; | |
181 | kobj->state_remove_uevent_sent = 0; | |
182 | kobj->state_initialized = 1; | |
183 | } | |
184 | ||
185 | ||
186 | static int kobject_add_internal(struct kobject *kobj) | |
187 | { | |
188 | int error = 0; | |
189 | struct kobject *parent; | |
190 | ||
191 | if (!kobj) | |
192 | return -ENOENT; | |
193 | ||
194 | if (!kobj->name || !kobj->name[0]) { | |
195 | WARN(1, "kobject: (%p): attempted to be registered with empty " | |
196 | "name!\n", kobj); | |
197 | return -EINVAL; | |
198 | } | |
199 | ||
200 | parent = kobject_get(kobj->parent); | |
201 | ||
202 | /* join kset if set, use it as parent if we do not already have one */ | |
203 | if (kobj->kset) { | |
204 | if (!parent) | |
205 | parent = kobject_get(&kobj->kset->kobj); | |
206 | kobj_kset_join(kobj); | |
207 | kobj->parent = parent; | |
208 | } | |
209 | ||
210 | pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n", | |
211 | kobject_name(kobj), kobj, __func__, | |
212 | parent ? kobject_name(parent) : "<NULL>", | |
213 | kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>"); | |
214 | ||
215 | error = create_dir(kobj); | |
216 | if (error) { | |
217 | kobj_kset_leave(kobj); | |
218 | kobject_put(parent); | |
219 | kobj->parent = NULL; | |
220 | ||
221 | /* be noisy on error issues */ | |
222 | if (error == -EEXIST) | |
223 | WARN(1, "%s failed for %s with " | |
224 | "-EEXIST, don't try to register things with " | |
225 | "the same name in the same directory.\n", | |
226 | __func__, kobject_name(kobj)); | |
227 | else | |
228 | WARN(1, "%s failed for %s (error: %d parent: %s)\n", | |
229 | __func__, kobject_name(kobj), error, | |
230 | parent ? kobject_name(parent) : "'none'"); | |
231 | } else | |
232 | kobj->state_in_sysfs = 1; | |
233 | ||
234 | return error; | |
235 | } | |
236 | ||
237 | /** | |
238 | * kobject_set_name_vargs - Set the name of an kobject | |
239 | * @kobj: struct kobject to set the name of | |
240 | * @fmt: format string used to build the name | |
241 | * @vargs: vargs to format the string. | |
242 | */ | |
243 | int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, | |
244 | va_list vargs) | |
245 | { | |
246 | const char *old_name = kobj->name; | |
247 | char *s; | |
248 | ||
249 | if (kobj->name && !fmt) | |
250 | return 0; | |
251 | ||
252 | kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); | |
253 | if (!kobj->name) | |
254 | return -ENOMEM; | |
255 | ||
256 | /* ewww... some of these buggers have '/' in the name ... */ | |
257 | while ((s = strchr(kobj->name, '/'))) | |
258 | s[0] = '!'; | |
259 | ||
260 | kfree(old_name); | |
261 | return 0; | |
262 | } | |
263 | ||
264 | /** | |
265 | * kobject_set_name - Set the name of a kobject | |
266 | * @kobj: struct kobject to set the name of | |
267 | * @fmt: format string used to build the name | |
268 | * | |
269 | * This sets the name of the kobject. If you have already added the | |
270 | * kobject to the system, you must call kobject_rename() in order to | |
271 | * change the name of the kobject. | |
272 | */ | |
273 | int kobject_set_name(struct kobject *kobj, const char *fmt, ...) | |
274 | { | |
275 | va_list vargs; | |
276 | int retval; | |
277 | ||
278 | va_start(vargs, fmt); | |
279 | retval = kobject_set_name_vargs(kobj, fmt, vargs); | |
280 | va_end(vargs); | |
281 | ||
282 | return retval; | |
283 | } | |
284 | EXPORT_SYMBOL(kobject_set_name); | |
285 | ||
286 | /** | |
287 | * kobject_init - initialize a kobject structure | |
288 | * @kobj: pointer to the kobject to initialize | |
289 | * @ktype: pointer to the ktype for this kobject. | |
290 | * | |
291 | * This function will properly initialize a kobject such that it can then | |
292 | * be passed to the kobject_add() call. | |
293 | * | |
294 | * After this function is called, the kobject MUST be cleaned up by a call | |
295 | * to kobject_put(), not by a call to kfree directly to ensure that all of | |
296 | * the memory is cleaned up properly. | |
297 | */ | |
298 | void kobject_init(struct kobject *kobj, struct kobj_type *ktype) | |
299 | { | |
300 | char *err_str; | |
301 | ||
302 | if (!kobj) { | |
303 | err_str = "invalid kobject pointer!"; | |
304 | goto error; | |
305 | } | |
306 | if (!ktype) { | |
307 | err_str = "must have a ktype to be initialized properly!\n"; | |
308 | goto error; | |
309 | } | |
310 | if (kobj->state_initialized) { | |
311 | /* do not error out as sometimes we can recover */ | |
312 | printk(KERN_ERR "kobject (%p): tried to init an initialized " | |
313 | "object, something is seriously wrong.\n", kobj); | |
314 | dump_stack(); | |
315 | } | |
316 | ||
317 | kobject_init_internal(kobj); | |
318 | kobj->ktype = ktype; | |
319 | return; | |
320 | ||
321 | error: | |
322 | printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str); | |
323 | dump_stack(); | |
324 | } | |
325 | EXPORT_SYMBOL(kobject_init); | |
326 | ||
327 | static int kobject_add_varg(struct kobject *kobj, struct kobject *parent, | |
328 | const char *fmt, va_list vargs) | |
329 | { | |
330 | int retval; | |
331 | ||
332 | retval = kobject_set_name_vargs(kobj, fmt, vargs); | |
333 | if (retval) { | |
334 | printk(KERN_ERR "kobject: can not set name properly!\n"); | |
335 | return retval; | |
336 | } | |
337 | kobj->parent = parent; | |
338 | return kobject_add_internal(kobj); | |
339 | } | |
340 | ||
341 | /** | |
342 | * kobject_add - the main kobject add function | |
343 | * @kobj: the kobject to add | |
344 | * @parent: pointer to the parent of the kobject. | |
345 | * @fmt: format to name the kobject with. | |
346 | * | |
347 | * The kobject name is set and added to the kobject hierarchy in this | |
348 | * function. | |
349 | * | |
350 | * If @parent is set, then the parent of the @kobj will be set to it. | |
351 | * If @parent is NULL, then the parent of the @kobj will be set to the | |
352 | * kobject associted with the kset assigned to this kobject. If no kset | |
353 | * is assigned to the kobject, then the kobject will be located in the | |
354 | * root of the sysfs tree. | |
355 | * | |
356 | * If this function returns an error, kobject_put() must be called to | |
357 | * properly clean up the memory associated with the object. | |
358 | * Under no instance should the kobject that is passed to this function | |
359 | * be directly freed with a call to kfree(), that can leak memory. | |
360 | * | |
361 | * Note, no "add" uevent will be created with this call, the caller should set | |
362 | * up all of the necessary sysfs files for the object and then call | |
363 | * kobject_uevent() with the UEVENT_ADD parameter to ensure that | |
364 | * userspace is properly notified of this kobject's creation. | |
365 | */ | |
366 | int kobject_add(struct kobject *kobj, struct kobject *parent, | |
367 | const char *fmt, ...) | |
368 | { | |
369 | va_list args; | |
370 | int retval; | |
371 | ||
372 | if (!kobj) | |
373 | return -EINVAL; | |
374 | ||
375 | if (!kobj->state_initialized) { | |
376 | printk(KERN_ERR "kobject '%s' (%p): tried to add an " | |
377 | "uninitialized object, something is seriously wrong.\n", | |
378 | kobject_name(kobj), kobj); | |
379 | dump_stack(); | |
380 | return -EINVAL; | |
381 | } | |
382 | va_start(args, fmt); | |
383 | retval = kobject_add_varg(kobj, parent, fmt, args); | |
384 | va_end(args); | |
385 | ||
386 | return retval; | |
387 | } | |
388 | EXPORT_SYMBOL(kobject_add); | |
389 | ||
390 | /** | |
391 | * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy | |
392 | * @kobj: pointer to the kobject to initialize | |
393 | * @ktype: pointer to the ktype for this kobject. | |
394 | * @parent: pointer to the parent of this kobject. | |
395 | * @fmt: the name of the kobject. | |
396 | * | |
397 | * This function combines the call to kobject_init() and | |
398 | * kobject_add(). The same type of error handling after a call to | |
399 | * kobject_add() and kobject lifetime rules are the same here. | |
400 | */ | |
401 | int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype, | |
402 | struct kobject *parent, const char *fmt, ...) | |
403 | { | |
404 | va_list args; | |
405 | int retval; | |
406 | ||
407 | kobject_init(kobj, ktype); | |
408 | ||
409 | va_start(args, fmt); | |
410 | retval = kobject_add_varg(kobj, parent, fmt, args); | |
411 | va_end(args); | |
412 | ||
413 | return retval; | |
414 | } | |
415 | EXPORT_SYMBOL_GPL(kobject_init_and_add); | |
416 | ||
417 | /** | |
418 | * kobject_rename - change the name of an object | |
419 | * @kobj: object in question. | |
420 | * @new_name: object's new name | |
421 | * | |
422 | * It is the responsibility of the caller to provide mutual | |
423 | * exclusion between two different calls of kobject_rename | |
424 | * on the same kobject and to ensure that new_name is valid and | |
425 | * won't conflict with other kobjects. | |
426 | */ | |
427 | int kobject_rename(struct kobject *kobj, const char *new_name) | |
428 | { | |
429 | int error = 0; | |
430 | const char *devpath = NULL; | |
431 | const char *dup_name = NULL, *name; | |
432 | char *devpath_string = NULL; | |
433 | char *envp[2]; | |
434 | ||
435 | kobj = kobject_get(kobj); | |
436 | if (!kobj) | |
437 | return -EINVAL; | |
438 | if (!kobj->parent) | |
439 | return -EINVAL; | |
440 | ||
441 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
442 | if (!devpath) { | |
443 | error = -ENOMEM; | |
444 | goto out; | |
445 | } | |
446 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); | |
447 | if (!devpath_string) { | |
448 | error = -ENOMEM; | |
449 | goto out; | |
450 | } | |
451 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); | |
452 | envp[0] = devpath_string; | |
453 | envp[1] = NULL; | |
454 | ||
455 | name = dup_name = kstrdup(new_name, GFP_KERNEL); | |
456 | if (!name) { | |
457 | error = -ENOMEM; | |
458 | goto out; | |
459 | } | |
460 | ||
461 | error = sysfs_rename_dir_ns(kobj, new_name, kobject_namespace(kobj)); | |
462 | if (error) | |
463 | goto out; | |
464 | ||
465 | /* Install the new kobject name */ | |
466 | dup_name = kobj->name; | |
467 | kobj->name = name; | |
468 | ||
469 | /* This function is mostly/only used for network interface. | |
470 | * Some hotplug package track interfaces by their name and | |
471 | * therefore want to know when the name is changed by the user. */ | |
472 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); | |
473 | ||
474 | out: | |
475 | kfree(dup_name); | |
476 | kfree(devpath_string); | |
477 | kfree(devpath); | |
478 | kobject_put(kobj); | |
479 | ||
480 | return error; | |
481 | } | |
482 | EXPORT_SYMBOL_GPL(kobject_rename); | |
483 | ||
484 | /** | |
485 | * kobject_move - move object to another parent | |
486 | * @kobj: object in question. | |
487 | * @new_parent: object's new parent (can be NULL) | |
488 | */ | |
489 | int kobject_move(struct kobject *kobj, struct kobject *new_parent) | |
490 | { | |
491 | int error; | |
492 | struct kobject *old_parent; | |
493 | const char *devpath = NULL; | |
494 | char *devpath_string = NULL; | |
495 | char *envp[2]; | |
496 | ||
497 | kobj = kobject_get(kobj); | |
498 | if (!kobj) | |
499 | return -EINVAL; | |
500 | new_parent = kobject_get(new_parent); | |
501 | if (!new_parent) { | |
502 | if (kobj->kset) | |
503 | new_parent = kobject_get(&kobj->kset->kobj); | |
504 | } | |
505 | ||
506 | /* old object path */ | |
507 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
508 | if (!devpath) { | |
509 | error = -ENOMEM; | |
510 | goto out; | |
511 | } | |
512 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); | |
513 | if (!devpath_string) { | |
514 | error = -ENOMEM; | |
515 | goto out; | |
516 | } | |
517 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); | |
518 | envp[0] = devpath_string; | |
519 | envp[1] = NULL; | |
520 | error = sysfs_move_dir_ns(kobj, new_parent, kobject_namespace(kobj)); | |
521 | if (error) | |
522 | goto out; | |
523 | old_parent = kobj->parent; | |
524 | kobj->parent = new_parent; | |
525 | new_parent = NULL; | |
526 | kobject_put(old_parent); | |
527 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); | |
528 | out: | |
529 | kobject_put(new_parent); | |
530 | kobject_put(kobj); | |
531 | kfree(devpath_string); | |
532 | kfree(devpath); | |
533 | return error; | |
534 | } | |
535 | ||
536 | /** | |
537 | * kobject_del - unlink kobject from hierarchy. | |
538 | * @kobj: object. | |
539 | */ | |
540 | void kobject_del(struct kobject *kobj) | |
541 | { | |
542 | struct sysfs_dirent *sd; | |
543 | ||
544 | if (!kobj) | |
545 | return; | |
546 | ||
547 | sd = kobj->sd; | |
548 | sysfs_remove_dir(kobj); | |
549 | sysfs_put(sd); | |
550 | ||
551 | kobj->state_in_sysfs = 0; | |
552 | kobj_kset_leave(kobj); | |
553 | kobject_put(kobj->parent); | |
554 | kobj->parent = NULL; | |
555 | } | |
556 | ||
557 | /** | |
558 | * kobject_get - increment refcount for object. | |
559 | * @kobj: object. | |
560 | */ | |
561 | struct kobject *kobject_get(struct kobject *kobj) | |
562 | { | |
563 | if (kobj) | |
564 | kref_get(&kobj->kref); | |
565 | return kobj; | |
566 | } | |
567 | ||
568 | static struct kobject * __must_check kobject_get_unless_zero(struct kobject *kobj) | |
569 | { | |
570 | if (!kref_get_unless_zero(&kobj->kref)) | |
571 | kobj = NULL; | |
572 | return kobj; | |
573 | } | |
574 | ||
575 | /* | |
576 | * kobject_cleanup - free kobject resources. | |
577 | * @kobj: object to cleanup | |
578 | */ | |
579 | static void kobject_cleanup(struct kobject *kobj) | |
580 | { | |
581 | struct kobj_type *t = get_ktype(kobj); | |
582 | const char *name = kobj->name; | |
583 | ||
584 | pr_debug("kobject: '%s' (%p): %s, parent %p\n", | |
585 | kobject_name(kobj), kobj, __func__, kobj->parent); | |
586 | ||
587 | if (t && !t->release) | |
588 | pr_debug("kobject: '%s' (%p): does not have a release() " | |
589 | "function, it is broken and must be fixed.\n", | |
590 | kobject_name(kobj), kobj); | |
591 | ||
592 | /* send "remove" if the caller did not do it but sent "add" */ | |
593 | if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) { | |
594 | pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n", | |
595 | kobject_name(kobj), kobj); | |
596 | kobject_uevent(kobj, KOBJ_REMOVE); | |
597 | } | |
598 | ||
599 | /* remove from sysfs if the caller did not do it */ | |
600 | if (kobj->state_in_sysfs) { | |
601 | pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n", | |
602 | kobject_name(kobj), kobj); | |
603 | kobject_del(kobj); | |
604 | } | |
605 | ||
606 | if (t && t->release) { | |
607 | pr_debug("kobject: '%s' (%p): calling ktype release\n", | |
608 | kobject_name(kobj), kobj); | |
609 | t->release(kobj); | |
610 | } | |
611 | ||
612 | /* free name if we allocated it */ | |
613 | if (name) { | |
614 | pr_debug("kobject: '%s': free name\n", name); | |
615 | kfree(name); | |
616 | } | |
617 | } | |
618 | ||
619 | #ifdef CONFIG_DEBUG_KOBJECT_RELEASE | |
620 | static void kobject_delayed_cleanup(struct work_struct *work) | |
621 | { | |
622 | kobject_cleanup(container_of(to_delayed_work(work), | |
623 | struct kobject, release)); | |
624 | } | |
625 | #endif | |
626 | ||
627 | static void kobject_release(struct kref *kref) | |
628 | { | |
629 | struct kobject *kobj = container_of(kref, struct kobject, kref); | |
630 | #ifdef CONFIG_DEBUG_KOBJECT_RELEASE | |
631 | pr_info("kobject: '%s' (%p): %s, parent %p (delayed)\n", | |
632 | kobject_name(kobj), kobj, __func__, kobj->parent); | |
633 | INIT_DELAYED_WORK(&kobj->release, kobject_delayed_cleanup); | |
634 | schedule_delayed_work(&kobj->release, HZ); | |
635 | #else | |
636 | kobject_cleanup(kobj); | |
637 | #endif | |
638 | } | |
639 | ||
640 | /** | |
641 | * kobject_put - decrement refcount for object. | |
642 | * @kobj: object. | |
643 | * | |
644 | * Decrement the refcount, and if 0, call kobject_cleanup(). | |
645 | */ | |
646 | void kobject_put(struct kobject *kobj) | |
647 | { | |
648 | if (kobj) { | |
649 | if (!kobj->state_initialized) | |
650 | WARN(1, KERN_WARNING "kobject: '%s' (%p): is not " | |
651 | "initialized, yet kobject_put() is being " | |
652 | "called.\n", kobject_name(kobj), kobj); | |
653 | kref_put(&kobj->kref, kobject_release); | |
654 | } | |
655 | } | |
656 | ||
657 | static void dynamic_kobj_release(struct kobject *kobj) | |
658 | { | |
659 | pr_debug("kobject: (%p): %s\n", kobj, __func__); | |
660 | kfree(kobj); | |
661 | } | |
662 | ||
663 | static struct kobj_type dynamic_kobj_ktype = { | |
664 | .release = dynamic_kobj_release, | |
665 | .sysfs_ops = &kobj_sysfs_ops, | |
666 | }; | |
667 | ||
668 | /** | |
669 | * kobject_create - create a struct kobject dynamically | |
670 | * | |
671 | * This function creates a kobject structure dynamically and sets it up | |
672 | * to be a "dynamic" kobject with a default release function set up. | |
673 | * | |
674 | * If the kobject was not able to be created, NULL will be returned. | |
675 | * The kobject structure returned from here must be cleaned up with a | |
676 | * call to kobject_put() and not kfree(), as kobject_init() has | |
677 | * already been called on this structure. | |
678 | */ | |
679 | struct kobject *kobject_create(void) | |
680 | { | |
681 | struct kobject *kobj; | |
682 | ||
683 | kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); | |
684 | if (!kobj) | |
685 | return NULL; | |
686 | ||
687 | kobject_init(kobj, &dynamic_kobj_ktype); | |
688 | return kobj; | |
689 | } | |
690 | ||
691 | /** | |
692 | * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs | |
693 | * | |
694 | * @name: the name for the kobject | |
695 | * @parent: the parent kobject of this kobject, if any. | |
696 | * | |
697 | * This function creates a kobject structure dynamically and registers it | |
698 | * with sysfs. When you are finished with this structure, call | |
699 | * kobject_put() and the structure will be dynamically freed when | |
700 | * it is no longer being used. | |
701 | * | |
702 | * If the kobject was not able to be created, NULL will be returned. | |
703 | */ | |
704 | struct kobject *kobject_create_and_add(const char *name, struct kobject *parent) | |
705 | { | |
706 | struct kobject *kobj; | |
707 | int retval; | |
708 | ||
709 | kobj = kobject_create(); | |
710 | if (!kobj) | |
711 | return NULL; | |
712 | ||
713 | retval = kobject_add(kobj, parent, "%s", name); | |
714 | if (retval) { | |
715 | printk(KERN_WARNING "%s: kobject_add error: %d\n", | |
716 | __func__, retval); | |
717 | kobject_put(kobj); | |
718 | kobj = NULL; | |
719 | } | |
720 | return kobj; | |
721 | } | |
722 | EXPORT_SYMBOL_GPL(kobject_create_and_add); | |
723 | ||
724 | /** | |
725 | * kset_init - initialize a kset for use | |
726 | * @k: kset | |
727 | */ | |
728 | void kset_init(struct kset *k) | |
729 | { | |
730 | kobject_init_internal(&k->kobj); | |
731 | INIT_LIST_HEAD(&k->list); | |
732 | spin_lock_init(&k->list_lock); | |
733 | } | |
734 | ||
735 | /* default kobject attribute operations */ | |
736 | static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr, | |
737 | char *buf) | |
738 | { | |
739 | struct kobj_attribute *kattr; | |
740 | ssize_t ret = -EIO; | |
741 | ||
742 | kattr = container_of(attr, struct kobj_attribute, attr); | |
743 | if (kattr->show) | |
744 | ret = kattr->show(kobj, kattr, buf); | |
745 | return ret; | |
746 | } | |
747 | ||
748 | static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr, | |
749 | const char *buf, size_t count) | |
750 | { | |
751 | struct kobj_attribute *kattr; | |
752 | ssize_t ret = -EIO; | |
753 | ||
754 | kattr = container_of(attr, struct kobj_attribute, attr); | |
755 | if (kattr->store) | |
756 | ret = kattr->store(kobj, kattr, buf, count); | |
757 | return ret; | |
758 | } | |
759 | ||
760 | const struct sysfs_ops kobj_sysfs_ops = { | |
761 | .show = kobj_attr_show, | |
762 | .store = kobj_attr_store, | |
763 | }; | |
764 | ||
765 | /** | |
766 | * kobj_completion_init - initialize a kobj_completion object. | |
767 | * @kc: kobj_completion | |
768 | * @ktype: type of kobject to initialize | |
769 | * | |
770 | * kobj_completion structures can be embedded within structures with different | |
771 | * lifetime rules. During the release of the enclosing object, we can | |
772 | * wait on the release of the kobject so that we don't free it while it's | |
773 | * still busy. | |
774 | */ | |
775 | void kobj_completion_init(struct kobj_completion *kc, struct kobj_type *ktype) | |
776 | { | |
777 | init_completion(&kc->kc_unregister); | |
778 | kobject_init(&kc->kc_kobj, ktype); | |
779 | } | |
780 | EXPORT_SYMBOL_GPL(kobj_completion_init); | |
781 | ||
782 | /** | |
783 | * kobj_completion_release - release a kobj_completion object | |
784 | * @kobj: kobject embedded in kobj_completion | |
785 | * | |
786 | * Used with kobject_release to notify waiters that the kobject has been | |
787 | * released. | |
788 | */ | |
789 | void kobj_completion_release(struct kobject *kobj) | |
790 | { | |
791 | struct kobj_completion *kc = kobj_to_kobj_completion(kobj); | |
792 | complete(&kc->kc_unregister); | |
793 | } | |
794 | EXPORT_SYMBOL_GPL(kobj_completion_release); | |
795 | ||
796 | /** | |
797 | * kobj_completion_del_and_wait - release the kobject and wait for it | |
798 | * @kc: kobj_completion object to release | |
799 | * | |
800 | * Delete the kobject from sysfs and drop the reference count. Then wait | |
801 | * until any other outstanding references are also dropped. This routine | |
802 | * is only necessary once other references may have been taken on the | |
803 | * kobject. Typically this happens when the kobject has been published | |
804 | * to sysfs via kobject_add. | |
805 | */ | |
806 | void kobj_completion_del_and_wait(struct kobj_completion *kc) | |
807 | { | |
808 | kobject_del(&kc->kc_kobj); | |
809 | kobject_put(&kc->kc_kobj); | |
810 | wait_for_completion(&kc->kc_unregister); | |
811 | } | |
812 | EXPORT_SYMBOL_GPL(kobj_completion_del_and_wait); | |
813 | ||
814 | /** | |
815 | * kset_register - initialize and add a kset. | |
816 | * @k: kset. | |
817 | */ | |
818 | int kset_register(struct kset *k) | |
819 | { | |
820 | int err; | |
821 | ||
822 | if (!k) | |
823 | return -EINVAL; | |
824 | ||
825 | kset_init(k); | |
826 | err = kobject_add_internal(&k->kobj); | |
827 | if (err) | |
828 | return err; | |
829 | kobject_uevent(&k->kobj, KOBJ_ADD); | |
830 | return 0; | |
831 | } | |
832 | ||
833 | /** | |
834 | * kset_unregister - remove a kset. | |
835 | * @k: kset. | |
836 | */ | |
837 | void kset_unregister(struct kset *k) | |
838 | { | |
839 | if (!k) | |
840 | return; | |
841 | kobject_put(&k->kobj); | |
842 | } | |
843 | ||
844 | /** | |
845 | * kset_find_obj - search for object in kset. | |
846 | * @kset: kset we're looking in. | |
847 | * @name: object's name. | |
848 | * | |
849 | * Lock kset via @kset->subsys, and iterate over @kset->list, | |
850 | * looking for a matching kobject. If matching object is found | |
851 | * take a reference and return the object. | |
852 | */ | |
853 | struct kobject *kset_find_obj(struct kset *kset, const char *name) | |
854 | { | |
855 | struct kobject *k; | |
856 | struct kobject *ret = NULL; | |
857 | ||
858 | spin_lock(&kset->list_lock); | |
859 | ||
860 | list_for_each_entry(k, &kset->list, entry) { | |
861 | if (kobject_name(k) && !strcmp(kobject_name(k), name)) { | |
862 | ret = kobject_get_unless_zero(k); | |
863 | break; | |
864 | } | |
865 | } | |
866 | ||
867 | spin_unlock(&kset->list_lock); | |
868 | return ret; | |
869 | } | |
870 | ||
871 | static void kset_release(struct kobject *kobj) | |
872 | { | |
873 | struct kset *kset = container_of(kobj, struct kset, kobj); | |
874 | pr_debug("kobject: '%s' (%p): %s\n", | |
875 | kobject_name(kobj), kobj, __func__); | |
876 | kfree(kset); | |
877 | } | |
878 | ||
879 | static struct kobj_type kset_ktype = { | |
880 | .sysfs_ops = &kobj_sysfs_ops, | |
881 | .release = kset_release, | |
882 | }; | |
883 | ||
884 | /** | |
885 | * kset_create - create a struct kset dynamically | |
886 | * | |
887 | * @name: the name for the kset | |
888 | * @uevent_ops: a struct kset_uevent_ops for the kset | |
889 | * @parent_kobj: the parent kobject of this kset, if any. | |
890 | * | |
891 | * This function creates a kset structure dynamically. This structure can | |
892 | * then be registered with the system and show up in sysfs with a call to | |
893 | * kset_register(). When you are finished with this structure, if | |
894 | * kset_register() has been called, call kset_unregister() and the | |
895 | * structure will be dynamically freed when it is no longer being used. | |
896 | * | |
897 | * If the kset was not able to be created, NULL will be returned. | |
898 | */ | |
899 | static struct kset *kset_create(const char *name, | |
900 | const struct kset_uevent_ops *uevent_ops, | |
901 | struct kobject *parent_kobj) | |
902 | { | |
903 | struct kset *kset; | |
904 | int retval; | |
905 | ||
906 | kset = kzalloc(sizeof(*kset), GFP_KERNEL); | |
907 | if (!kset) | |
908 | return NULL; | |
909 | retval = kobject_set_name(&kset->kobj, "%s", name); | |
910 | if (retval) { | |
911 | kfree(kset); | |
912 | return NULL; | |
913 | } | |
914 | kset->uevent_ops = uevent_ops; | |
915 | kset->kobj.parent = parent_kobj; | |
916 | ||
917 | /* | |
918 | * The kobject of this kset will have a type of kset_ktype and belong to | |
919 | * no kset itself. That way we can properly free it when it is | |
920 | * finished being used. | |
921 | */ | |
922 | kset->kobj.ktype = &kset_ktype; | |
923 | kset->kobj.kset = NULL; | |
924 | ||
925 | return kset; | |
926 | } | |
927 | ||
928 | /** | |
929 | * kset_create_and_add - create a struct kset dynamically and add it to sysfs | |
930 | * | |
931 | * @name: the name for the kset | |
932 | * @uevent_ops: a struct kset_uevent_ops for the kset | |
933 | * @parent_kobj: the parent kobject of this kset, if any. | |
934 | * | |
935 | * This function creates a kset structure dynamically and registers it | |
936 | * with sysfs. When you are finished with this structure, call | |
937 | * kset_unregister() and the structure will be dynamically freed when it | |
938 | * is no longer being used. | |
939 | * | |
940 | * If the kset was not able to be created, NULL will be returned. | |
941 | */ | |
942 | struct kset *kset_create_and_add(const char *name, | |
943 | const struct kset_uevent_ops *uevent_ops, | |
944 | struct kobject *parent_kobj) | |
945 | { | |
946 | struct kset *kset; | |
947 | int error; | |
948 | ||
949 | kset = kset_create(name, uevent_ops, parent_kobj); | |
950 | if (!kset) | |
951 | return NULL; | |
952 | error = kset_register(kset); | |
953 | if (error) { | |
954 | kfree(kset); | |
955 | return NULL; | |
956 | } | |
957 | return kset; | |
958 | } | |
959 | EXPORT_SYMBOL_GPL(kset_create_and_add); | |
960 | ||
961 | ||
962 | static DEFINE_SPINLOCK(kobj_ns_type_lock); | |
963 | static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES]; | |
964 | ||
965 | int kobj_ns_type_register(const struct kobj_ns_type_operations *ops) | |
966 | { | |
967 | enum kobj_ns_type type = ops->type; | |
968 | int error; | |
969 | ||
970 | spin_lock(&kobj_ns_type_lock); | |
971 | ||
972 | error = -EINVAL; | |
973 | if (type >= KOBJ_NS_TYPES) | |
974 | goto out; | |
975 | ||
976 | error = -EINVAL; | |
977 | if (type <= KOBJ_NS_TYPE_NONE) | |
978 | goto out; | |
979 | ||
980 | error = -EBUSY; | |
981 | if (kobj_ns_ops_tbl[type]) | |
982 | goto out; | |
983 | ||
984 | error = 0; | |
985 | kobj_ns_ops_tbl[type] = ops; | |
986 | ||
987 | out: | |
988 | spin_unlock(&kobj_ns_type_lock); | |
989 | return error; | |
990 | } | |
991 | ||
992 | int kobj_ns_type_registered(enum kobj_ns_type type) | |
993 | { | |
994 | int registered = 0; | |
995 | ||
996 | spin_lock(&kobj_ns_type_lock); | |
997 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES)) | |
998 | registered = kobj_ns_ops_tbl[type] != NULL; | |
999 | spin_unlock(&kobj_ns_type_lock); | |
1000 | ||
1001 | return registered; | |
1002 | } | |
1003 | ||
1004 | const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent) | |
1005 | { | |
1006 | const struct kobj_ns_type_operations *ops = NULL; | |
1007 | ||
1008 | if (parent && parent->ktype->child_ns_type) | |
1009 | ops = parent->ktype->child_ns_type(parent); | |
1010 | ||
1011 | return ops; | |
1012 | } | |
1013 | ||
1014 | const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj) | |
1015 | { | |
1016 | return kobj_child_ns_ops(kobj->parent); | |
1017 | } | |
1018 | ||
1019 | bool kobj_ns_current_may_mount(enum kobj_ns_type type) | |
1020 | { | |
1021 | bool may_mount = true; | |
1022 | ||
1023 | spin_lock(&kobj_ns_type_lock); | |
1024 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
1025 | kobj_ns_ops_tbl[type]) | |
1026 | may_mount = kobj_ns_ops_tbl[type]->current_may_mount(); | |
1027 | spin_unlock(&kobj_ns_type_lock); | |
1028 | ||
1029 | return may_mount; | |
1030 | } | |
1031 | ||
1032 | void *kobj_ns_grab_current(enum kobj_ns_type type) | |
1033 | { | |
1034 | void *ns = NULL; | |
1035 | ||
1036 | spin_lock(&kobj_ns_type_lock); | |
1037 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
1038 | kobj_ns_ops_tbl[type]) | |
1039 | ns = kobj_ns_ops_tbl[type]->grab_current_ns(); | |
1040 | spin_unlock(&kobj_ns_type_lock); | |
1041 | ||
1042 | return ns; | |
1043 | } | |
1044 | ||
1045 | const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk) | |
1046 | { | |
1047 | const void *ns = NULL; | |
1048 | ||
1049 | spin_lock(&kobj_ns_type_lock); | |
1050 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
1051 | kobj_ns_ops_tbl[type]) | |
1052 | ns = kobj_ns_ops_tbl[type]->netlink_ns(sk); | |
1053 | spin_unlock(&kobj_ns_type_lock); | |
1054 | ||
1055 | return ns; | |
1056 | } | |
1057 | ||
1058 | const void *kobj_ns_initial(enum kobj_ns_type type) | |
1059 | { | |
1060 | const void *ns = NULL; | |
1061 | ||
1062 | spin_lock(&kobj_ns_type_lock); | |
1063 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
1064 | kobj_ns_ops_tbl[type]) | |
1065 | ns = kobj_ns_ops_tbl[type]->initial_ns(); | |
1066 | spin_unlock(&kobj_ns_type_lock); | |
1067 | ||
1068 | return ns; | |
1069 | } | |
1070 | ||
1071 | void kobj_ns_drop(enum kobj_ns_type type, void *ns) | |
1072 | { | |
1073 | spin_lock(&kobj_ns_type_lock); | |
1074 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
1075 | kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns) | |
1076 | kobj_ns_ops_tbl[type]->drop_ns(ns); | |
1077 | spin_unlock(&kobj_ns_type_lock); | |
1078 | } | |
1079 | ||
1080 | EXPORT_SYMBOL(kobject_get); | |
1081 | EXPORT_SYMBOL(kobject_put); | |
1082 | EXPORT_SYMBOL(kobject_del); | |
1083 | ||
1084 | EXPORT_SYMBOL(kset_register); | |
1085 | EXPORT_SYMBOL(kset_unregister); |