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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 | WARN(1, "kobject: (%p): attempted to be registered with empty " | |
168 | "name!\n", kobj); | |
169 | return -EINVAL; | |
170 | } | |
171 | ||
172 | parent = kobject_get(kobj->parent); | |
173 | ||
174 | /* join kset if set, use it as parent if we do not already have one */ | |
175 | if (kobj->kset) { | |
176 | if (!parent) | |
177 | parent = kobject_get(&kobj->kset->kobj); | |
178 | kobj_kset_join(kobj); | |
179 | kobj->parent = parent; | |
180 | } | |
181 | ||
182 | pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n", | |
183 | kobject_name(kobj), kobj, __func__, | |
184 | parent ? kobject_name(parent) : "<NULL>", | |
185 | kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>"); | |
186 | ||
187 | error = create_dir(kobj); | |
188 | if (error) { | |
189 | kobj_kset_leave(kobj); | |
190 | kobject_put(parent); | |
191 | kobj->parent = NULL; | |
192 | ||
193 | /* be noisy on error issues */ | |
194 | if (error == -EEXIST) | |
195 | printk(KERN_ERR "%s failed for %s with " | |
196 | "-EEXIST, don't try to register things with " | |
197 | "the same name in the same directory.\n", | |
198 | __func__, kobject_name(kobj)); | |
199 | else | |
200 | printk(KERN_ERR "%s failed for %s (%d)\n", | |
201 | __func__, kobject_name(kobj), error); | |
202 | dump_stack(); | |
203 | } else | |
204 | kobj->state_in_sysfs = 1; | |
205 | ||
206 | return error; | |
207 | } | |
208 | ||
209 | /** | |
210 | * kobject_set_name_vargs - Set the name of an kobject | |
211 | * @kobj: struct kobject to set the name of | |
212 | * @fmt: format string used to build the name | |
213 | * @vargs: vargs to format the string. | |
214 | */ | |
215 | int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, | |
216 | va_list vargs) | |
217 | { | |
218 | const char *old_name = kobj->name; | |
219 | char *s; | |
220 | ||
221 | if (kobj->name && !fmt) | |
222 | return 0; | |
223 | ||
224 | kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); | |
225 | if (!kobj->name) | |
226 | return -ENOMEM; | |
227 | ||
228 | /* ewww... some of these buggers have '/' in the name ... */ | |
229 | while ((s = strchr(kobj->name, '/'))) | |
230 | s[0] = '!'; | |
231 | ||
232 | kfree(old_name); | |
233 | return 0; | |
234 | } | |
235 | ||
236 | /** | |
237 | * kobject_set_name - Set the name of a kobject | |
238 | * @kobj: struct kobject to set the name of | |
239 | * @fmt: format string used to build the name | |
240 | * | |
241 | * This sets the name of the kobject. If you have already added the | |
242 | * kobject to the system, you must call kobject_rename() in order to | |
243 | * change the name of the kobject. | |
244 | */ | |
245 | int kobject_set_name(struct kobject *kobj, const char *fmt, ...) | |
246 | { | |
247 | va_list vargs; | |
248 | int retval; | |
249 | ||
250 | va_start(vargs, fmt); | |
251 | retval = kobject_set_name_vargs(kobj, fmt, vargs); | |
252 | va_end(vargs); | |
253 | ||
254 | return retval; | |
255 | } | |
256 | EXPORT_SYMBOL(kobject_set_name); | |
257 | ||
258 | /** | |
259 | * kobject_init - initialize a kobject structure | |
260 | * @kobj: pointer to the kobject to initialize | |
261 | * @ktype: pointer to the ktype for this kobject. | |
262 | * | |
263 | * This function will properly initialize a kobject such that it can then | |
264 | * be passed to the kobject_add() call. | |
265 | * | |
266 | * After this function is called, the kobject MUST be cleaned up by a call | |
267 | * to kobject_put(), not by a call to kfree directly to ensure that all of | |
268 | * the memory is cleaned up properly. | |
269 | */ | |
270 | void kobject_init(struct kobject *kobj, struct kobj_type *ktype) | |
271 | { | |
272 | char *err_str; | |
273 | ||
274 | if (!kobj) { | |
275 | err_str = "invalid kobject pointer!"; | |
276 | goto error; | |
277 | } | |
278 | if (!ktype) { | |
279 | err_str = "must have a ktype to be initialized properly!\n"; | |
280 | goto error; | |
281 | } | |
282 | if (kobj->state_initialized) { | |
283 | /* do not error out as sometimes we can recover */ | |
284 | printk(KERN_ERR "kobject (%p): tried to init an initialized " | |
285 | "object, something is seriously wrong.\n", kobj); | |
286 | dump_stack(); | |
287 | } | |
288 | ||
289 | kobject_init_internal(kobj); | |
290 | kobj->ktype = ktype; | |
291 | return; | |
292 | ||
293 | error: | |
294 | printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str); | |
295 | dump_stack(); | |
296 | } | |
297 | EXPORT_SYMBOL(kobject_init); | |
298 | ||
299 | static int kobject_add_varg(struct kobject *kobj, struct kobject *parent, | |
300 | const char *fmt, va_list vargs) | |
301 | { | |
302 | int retval; | |
303 | ||
304 | retval = kobject_set_name_vargs(kobj, fmt, vargs); | |
305 | if (retval) { | |
306 | printk(KERN_ERR "kobject: can not set name properly!\n"); | |
307 | return retval; | |
308 | } | |
309 | kobj->parent = parent; | |
310 | return kobject_add_internal(kobj); | |
311 | } | |
312 | ||
313 | /** | |
314 | * kobject_add - the main kobject add function | |
315 | * @kobj: the kobject to add | |
316 | * @parent: pointer to the parent of the kobject. | |
317 | * @fmt: format to name the kobject with. | |
318 | * | |
319 | * The kobject name is set and added to the kobject hierarchy in this | |
320 | * function. | |
321 | * | |
322 | * If @parent is set, then the parent of the @kobj will be set to it. | |
323 | * If @parent is NULL, then the parent of the @kobj will be set to the | |
324 | * kobject associted with the kset assigned to this kobject. If no kset | |
325 | * is assigned to the kobject, then the kobject will be located in the | |
326 | * root of the sysfs tree. | |
327 | * | |
328 | * If this function returns an error, kobject_put() must be called to | |
329 | * properly clean up the memory associated with the object. | |
330 | * Under no instance should the kobject that is passed to this function | |
331 | * be directly freed with a call to kfree(), that can leak memory. | |
332 | * | |
333 | * Note, no "add" uevent will be created with this call, the caller should set | |
334 | * up all of the necessary sysfs files for the object and then call | |
335 | * kobject_uevent() with the UEVENT_ADD parameter to ensure that | |
336 | * userspace is properly notified of this kobject's creation. | |
337 | */ | |
338 | int kobject_add(struct kobject *kobj, struct kobject *parent, | |
339 | const char *fmt, ...) | |
340 | { | |
341 | va_list args; | |
342 | int retval; | |
343 | ||
344 | if (!kobj) | |
345 | return -EINVAL; | |
346 | ||
347 | if (!kobj->state_initialized) { | |
348 | printk(KERN_ERR "kobject '%s' (%p): tried to add an " | |
349 | "uninitialized object, something is seriously wrong.\n", | |
350 | kobject_name(kobj), kobj); | |
351 | dump_stack(); | |
352 | return -EINVAL; | |
353 | } | |
354 | va_start(args, fmt); | |
355 | retval = kobject_add_varg(kobj, parent, fmt, args); | |
356 | va_end(args); | |
357 | ||
358 | return retval; | |
359 | } | |
360 | EXPORT_SYMBOL(kobject_add); | |
361 | ||
362 | /** | |
363 | * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy | |
364 | * @kobj: pointer to the kobject to initialize | |
365 | * @ktype: pointer to the ktype for this kobject. | |
366 | * @parent: pointer to the parent of this kobject. | |
367 | * @fmt: the name of the kobject. | |
368 | * | |
369 | * This function combines the call to kobject_init() and | |
370 | * kobject_add(). The same type of error handling after a call to | |
371 | * kobject_add() and kobject lifetime rules are the same here. | |
372 | */ | |
373 | int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype, | |
374 | struct kobject *parent, const char *fmt, ...) | |
375 | { | |
376 | va_list args; | |
377 | int retval; | |
378 | ||
379 | kobject_init(kobj, ktype); | |
380 | ||
381 | va_start(args, fmt); | |
382 | retval = kobject_add_varg(kobj, parent, fmt, args); | |
383 | va_end(args); | |
384 | ||
385 | return retval; | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(kobject_init_and_add); | |
388 | ||
389 | /** | |
390 | * kobject_rename - change the name of an object | |
391 | * @kobj: object in question. | |
392 | * @new_name: object's new name | |
393 | * | |
394 | * It is the responsibility of the caller to provide mutual | |
395 | * exclusion between two different calls of kobject_rename | |
396 | * on the same kobject and to ensure that new_name is valid and | |
397 | * won't conflict with other kobjects. | |
398 | */ | |
399 | int kobject_rename(struct kobject *kobj, const char *new_name) | |
400 | { | |
401 | int error = 0; | |
402 | const char *devpath = NULL; | |
403 | const char *dup_name = NULL, *name; | |
404 | char *devpath_string = NULL; | |
405 | char *envp[2]; | |
406 | ||
407 | kobj = kobject_get(kobj); | |
408 | if (!kobj) | |
409 | return -EINVAL; | |
410 | if (!kobj->parent) | |
411 | return -EINVAL; | |
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 | name = dup_name = kstrdup(new_name, GFP_KERNEL); | |
428 | if (!name) { | |
429 | error = -ENOMEM; | |
430 | goto out; | |
431 | } | |
432 | ||
433 | error = sysfs_rename_dir(kobj, new_name); | |
434 | if (error) | |
435 | goto out; | |
436 | ||
437 | /* Install the new kobject name */ | |
438 | dup_name = kobj->name; | |
439 | kobj->name = name; | |
440 | ||
441 | /* This function is mostly/only used for network interface. | |
442 | * Some hotplug package track interfaces by their name and | |
443 | * therefore want to know when the name is changed by the user. */ | |
444 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); | |
445 | ||
446 | out: | |
447 | kfree(dup_name); | |
448 | kfree(devpath_string); | |
449 | kfree(devpath); | |
450 | kobject_put(kobj); | |
451 | ||
452 | return error; | |
453 | } | |
454 | EXPORT_SYMBOL_GPL(kobject_rename); | |
455 | ||
456 | /** | |
457 | * kobject_move - move object to another parent | |
458 | * @kobj: object in question. | |
459 | * @new_parent: object's new parent (can be NULL) | |
460 | */ | |
461 | int kobject_move(struct kobject *kobj, struct kobject *new_parent) | |
462 | { | |
463 | int error; | |
464 | struct kobject *old_parent; | |
465 | const char *devpath = NULL; | |
466 | char *devpath_string = NULL; | |
467 | char *envp[2]; | |
468 | ||
469 | kobj = kobject_get(kobj); | |
470 | if (!kobj) | |
471 | return -EINVAL; | |
472 | new_parent = kobject_get(new_parent); | |
473 | if (!new_parent) { | |
474 | if (kobj->kset) | |
475 | new_parent = kobject_get(&kobj->kset->kobj); | |
476 | } | |
477 | /* old object path */ | |
478 | devpath = kobject_get_path(kobj, GFP_KERNEL); | |
479 | if (!devpath) { | |
480 | error = -ENOMEM; | |
481 | goto out; | |
482 | } | |
483 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); | |
484 | if (!devpath_string) { | |
485 | error = -ENOMEM; | |
486 | goto out; | |
487 | } | |
488 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); | |
489 | envp[0] = devpath_string; | |
490 | envp[1] = NULL; | |
491 | error = sysfs_move_dir(kobj, new_parent); | |
492 | if (error) | |
493 | goto out; | |
494 | old_parent = kobj->parent; | |
495 | kobj->parent = new_parent; | |
496 | new_parent = NULL; | |
497 | kobject_put(old_parent); | |
498 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); | |
499 | out: | |
500 | kobject_put(new_parent); | |
501 | kobject_put(kobj); | |
502 | kfree(devpath_string); | |
503 | kfree(devpath); | |
504 | return error; | |
505 | } | |
506 | ||
507 | /** | |
508 | * kobject_del - unlink kobject from hierarchy. | |
509 | * @kobj: object. | |
510 | */ | |
511 | void kobject_del(struct kobject *kobj) | |
512 | { | |
513 | if (!kobj) | |
514 | return; | |
515 | ||
516 | sysfs_remove_dir(kobj); | |
517 | kobj->state_in_sysfs = 0; | |
518 | kobj_kset_leave(kobj); | |
519 | kobject_put(kobj->parent); | |
520 | kobj->parent = NULL; | |
521 | } | |
522 | ||
523 | /** | |
524 | * kobject_get - increment refcount for object. | |
525 | * @kobj: object. | |
526 | */ | |
527 | struct kobject *kobject_get(struct kobject *kobj) | |
528 | { | |
529 | if (kobj) | |
530 | kref_get(&kobj->kref); | |
531 | return kobj; | |
532 | } | |
533 | ||
534 | /* | |
535 | * kobject_cleanup - free kobject resources. | |
536 | * @kobj: object to cleanup | |
537 | */ | |
538 | static void kobject_cleanup(struct kobject *kobj) | |
539 | { | |
540 | struct kobj_type *t = get_ktype(kobj); | |
541 | const char *name = kobj->name; | |
542 | ||
543 | pr_debug("kobject: '%s' (%p): %s\n", | |
544 | kobject_name(kobj), kobj, __func__); | |
545 | ||
546 | if (t && !t->release) | |
547 | pr_debug("kobject: '%s' (%p): does not have a release() " | |
548 | "function, it is broken and must be fixed.\n", | |
549 | kobject_name(kobj), kobj); | |
550 | ||
551 | /* send "remove" if the caller did not do it but sent "add" */ | |
552 | if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) { | |
553 | pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n", | |
554 | kobject_name(kobj), kobj); | |
555 | kobject_uevent(kobj, KOBJ_REMOVE); | |
556 | } | |
557 | ||
558 | /* remove from sysfs if the caller did not do it */ | |
559 | if (kobj->state_in_sysfs) { | |
560 | pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n", | |
561 | kobject_name(kobj), kobj); | |
562 | kobject_del(kobj); | |
563 | } | |
564 | ||
565 | if (t && t->release) { | |
566 | pr_debug("kobject: '%s' (%p): calling ktype release\n", | |
567 | kobject_name(kobj), kobj); | |
568 | t->release(kobj); | |
569 | } | |
570 | ||
571 | /* free name if we allocated it */ | |
572 | if (name) { | |
573 | pr_debug("kobject: '%s': free name\n", name); | |
574 | kfree(name); | |
575 | } | |
576 | } | |
577 | ||
578 | static void kobject_release(struct kref *kref) | |
579 | { | |
580 | kobject_cleanup(container_of(kref, struct kobject, kref)); | |
581 | } | |
582 | ||
583 | /** | |
584 | * kobject_put - decrement refcount for object. | |
585 | * @kobj: object. | |
586 | * | |
587 | * Decrement the refcount, and if 0, call kobject_cleanup(). | |
588 | */ | |
589 | void kobject_put(struct kobject *kobj) | |
590 | { | |
591 | if (kobj) { | |
592 | if (!kobj->state_initialized) | |
593 | WARN(1, KERN_WARNING "kobject: '%s' (%p): is not " | |
594 | "initialized, yet kobject_put() is being " | |
595 | "called.\n", kobject_name(kobj), kobj); | |
596 | kref_put(&kobj->kref, kobject_release); | |
597 | } | |
598 | } | |
599 | ||
600 | static void dynamic_kobj_release(struct kobject *kobj) | |
601 | { | |
602 | pr_debug("kobject: (%p): %s\n", kobj, __func__); | |
603 | kfree(kobj); | |
604 | } | |
605 | ||
606 | static struct kobj_type dynamic_kobj_ktype = { | |
607 | .release = dynamic_kobj_release, | |
608 | .sysfs_ops = &kobj_sysfs_ops, | |
609 | }; | |
610 | ||
611 | /** | |
612 | * kobject_create - create a struct kobject dynamically | |
613 | * | |
614 | * This function creates a kobject structure dynamically and sets it up | |
615 | * to be a "dynamic" kobject with a default release function set up. | |
616 | * | |
617 | * If the kobject was not able to be created, NULL will be returned. | |
618 | * The kobject structure returned from here must be cleaned up with a | |
619 | * call to kobject_put() and not kfree(), as kobject_init() has | |
620 | * already been called on this structure. | |
621 | */ | |
622 | struct kobject *kobject_create(void) | |
623 | { | |
624 | struct kobject *kobj; | |
625 | ||
626 | kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); | |
627 | if (!kobj) | |
628 | return NULL; | |
629 | ||
630 | kobject_init(kobj, &dynamic_kobj_ktype); | |
631 | return kobj; | |
632 | } | |
633 | ||
634 | /** | |
635 | * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs | |
636 | * | |
637 | * @name: the name for the kset | |
638 | * @parent: the parent kobject of this kobject, if any. | |
639 | * | |
640 | * This function creates a kobject structure dynamically and registers it | |
641 | * with sysfs. When you are finished with this structure, call | |
642 | * kobject_put() and the structure will be dynamically freed when | |
643 | * it is no longer being used. | |
644 | * | |
645 | * If the kobject was not able to be created, NULL will be returned. | |
646 | */ | |
647 | struct kobject *kobject_create_and_add(const char *name, struct kobject *parent) | |
648 | { | |
649 | struct kobject *kobj; | |
650 | int retval; | |
651 | ||
652 | kobj = kobject_create(); | |
653 | if (!kobj) | |
654 | return NULL; | |
655 | ||
656 | retval = kobject_add(kobj, parent, "%s", name); | |
657 | if (retval) { | |
658 | printk(KERN_WARNING "%s: kobject_add error: %d\n", | |
659 | __func__, retval); | |
660 | kobject_put(kobj); | |
661 | kobj = NULL; | |
662 | } | |
663 | return kobj; | |
664 | } | |
665 | EXPORT_SYMBOL_GPL(kobject_create_and_add); | |
666 | ||
667 | /** | |
668 | * kset_init - initialize a kset for use | |
669 | * @k: kset | |
670 | */ | |
671 | void kset_init(struct kset *k) | |
672 | { | |
673 | kobject_init_internal(&k->kobj); | |
674 | INIT_LIST_HEAD(&k->list); | |
675 | spin_lock_init(&k->list_lock); | |
676 | } | |
677 | ||
678 | /* default kobject attribute operations */ | |
679 | static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr, | |
680 | char *buf) | |
681 | { | |
682 | struct kobj_attribute *kattr; | |
683 | ssize_t ret = -EIO; | |
684 | ||
685 | kattr = container_of(attr, struct kobj_attribute, attr); | |
686 | if (kattr->show) | |
687 | ret = kattr->show(kobj, kattr, buf); | |
688 | return ret; | |
689 | } | |
690 | ||
691 | static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr, | |
692 | const char *buf, size_t count) | |
693 | { | |
694 | struct kobj_attribute *kattr; | |
695 | ssize_t ret = -EIO; | |
696 | ||
697 | kattr = container_of(attr, struct kobj_attribute, attr); | |
698 | if (kattr->store) | |
699 | ret = kattr->store(kobj, kattr, buf, count); | |
700 | return ret; | |
701 | } | |
702 | ||
703 | const struct sysfs_ops kobj_sysfs_ops = { | |
704 | .show = kobj_attr_show, | |
705 | .store = kobj_attr_store, | |
706 | }; | |
707 | ||
708 | /** | |
709 | * kset_register - initialize and add a kset. | |
710 | * @k: kset. | |
711 | */ | |
712 | int kset_register(struct kset *k) | |
713 | { | |
714 | int err; | |
715 | ||
716 | if (!k) | |
717 | return -EINVAL; | |
718 | ||
719 | kset_init(k); | |
720 | err = kobject_add_internal(&k->kobj); | |
721 | if (err) | |
722 | return err; | |
723 | kobject_uevent(&k->kobj, KOBJ_ADD); | |
724 | return 0; | |
725 | } | |
726 | ||
727 | /** | |
728 | * kset_unregister - remove a kset. | |
729 | * @k: kset. | |
730 | */ | |
731 | void kset_unregister(struct kset *k) | |
732 | { | |
733 | if (!k) | |
734 | return; | |
735 | kobject_put(&k->kobj); | |
736 | } | |
737 | ||
738 | /** | |
739 | * kset_find_obj - search for object in kset. | |
740 | * @kset: kset we're looking in. | |
741 | * @name: object's name. | |
742 | * | |
743 | * Lock kset via @kset->subsys, and iterate over @kset->list, | |
744 | * looking for a matching kobject. If matching object is found | |
745 | * take a reference and return the object. | |
746 | */ | |
747 | struct kobject *kset_find_obj(struct kset *kset, const char *name) | |
748 | { | |
749 | return kset_find_obj_hinted(kset, name, NULL); | |
750 | } | |
751 | ||
752 | /** | |
753 | * kset_find_obj_hinted - search for object in kset given a predecessor hint. | |
754 | * @kset: kset we're looking in. | |
755 | * @name: object's name. | |
756 | * @hint: hint to possible object's predecessor. | |
757 | * | |
758 | * Check the hint's next object and if it is a match return it directly, | |
759 | * otherwise, fall back to the behavior of kset_find_obj(). Either way | |
760 | * a reference for the returned object is held and the reference on the | |
761 | * hinted object is released. | |
762 | */ | |
763 | struct kobject *kset_find_obj_hinted(struct kset *kset, const char *name, | |
764 | struct kobject *hint) | |
765 | { | |
766 | struct kobject *k; | |
767 | struct kobject *ret = NULL; | |
768 | ||
769 | spin_lock(&kset->list_lock); | |
770 | ||
771 | if (!hint) | |
772 | goto slow_search; | |
773 | ||
774 | /* end of list detection */ | |
775 | if (hint->entry.next == kset->list.next) | |
776 | goto slow_search; | |
777 | ||
778 | k = container_of(hint->entry.next, struct kobject, entry); | |
779 | if (!kobject_name(k) || strcmp(kobject_name(k), name)) | |
780 | goto slow_search; | |
781 | ||
782 | ret = kobject_get(k); | |
783 | goto unlock_exit; | |
784 | ||
785 | slow_search: | |
786 | list_for_each_entry(k, &kset->list, entry) { | |
787 | if (kobject_name(k) && !strcmp(kobject_name(k), name)) { | |
788 | ret = kobject_get(k); | |
789 | break; | |
790 | } | |
791 | } | |
792 | ||
793 | unlock_exit: | |
794 | spin_unlock(&kset->list_lock); | |
795 | ||
796 | if (hint) | |
797 | kobject_put(hint); | |
798 | ||
799 | return ret; | |
800 | } | |
801 | ||
802 | static void kset_release(struct kobject *kobj) | |
803 | { | |
804 | struct kset *kset = container_of(kobj, struct kset, kobj); | |
805 | pr_debug("kobject: '%s' (%p): %s\n", | |
806 | kobject_name(kobj), kobj, __func__); | |
807 | kfree(kset); | |
808 | } | |
809 | ||
810 | static struct kobj_type kset_ktype = { | |
811 | .sysfs_ops = &kobj_sysfs_ops, | |
812 | .release = kset_release, | |
813 | }; | |
814 | ||
815 | /** | |
816 | * kset_create - create a struct kset dynamically | |
817 | * | |
818 | * @name: the name for the kset | |
819 | * @uevent_ops: a struct kset_uevent_ops for the kset | |
820 | * @parent_kobj: the parent kobject of this kset, if any. | |
821 | * | |
822 | * This function creates a kset structure dynamically. This structure can | |
823 | * then be registered with the system and show up in sysfs with a call to | |
824 | * kset_register(). When you are finished with this structure, if | |
825 | * kset_register() has been called, call kset_unregister() and the | |
826 | * structure will be dynamically freed when it is no longer being used. | |
827 | * | |
828 | * If the kset was not able to be created, NULL will be returned. | |
829 | */ | |
830 | static struct kset *kset_create(const char *name, | |
831 | const struct kset_uevent_ops *uevent_ops, | |
832 | struct kobject *parent_kobj) | |
833 | { | |
834 | struct kset *kset; | |
835 | int retval; | |
836 | ||
837 | kset = kzalloc(sizeof(*kset), GFP_KERNEL); | |
838 | if (!kset) | |
839 | return NULL; | |
840 | retval = kobject_set_name(&kset->kobj, name); | |
841 | if (retval) { | |
842 | kfree(kset); | |
843 | return NULL; | |
844 | } | |
845 | kset->uevent_ops = uevent_ops; | |
846 | kset->kobj.parent = parent_kobj; | |
847 | ||
848 | /* | |
849 | * The kobject of this kset will have a type of kset_ktype and belong to | |
850 | * no kset itself. That way we can properly free it when it is | |
851 | * finished being used. | |
852 | */ | |
853 | kset->kobj.ktype = &kset_ktype; | |
854 | kset->kobj.kset = NULL; | |
855 | ||
856 | return kset; | |
857 | } | |
858 | ||
859 | /** | |
860 | * kset_create_and_add - create a struct kset dynamically and add it to sysfs | |
861 | * | |
862 | * @name: the name for the kset | |
863 | * @uevent_ops: a struct kset_uevent_ops for the kset | |
864 | * @parent_kobj: the parent kobject of this kset, if any. | |
865 | * | |
866 | * This function creates a kset structure dynamically and registers it | |
867 | * with sysfs. When you are finished with this structure, call | |
868 | * kset_unregister() and the structure will be dynamically freed when it | |
869 | * is no longer being used. | |
870 | * | |
871 | * If the kset was not able to be created, NULL will be returned. | |
872 | */ | |
873 | struct kset *kset_create_and_add(const char *name, | |
874 | const struct kset_uevent_ops *uevent_ops, | |
875 | struct kobject *parent_kobj) | |
876 | { | |
877 | struct kset *kset; | |
878 | int error; | |
879 | ||
880 | kset = kset_create(name, uevent_ops, parent_kobj); | |
881 | if (!kset) | |
882 | return NULL; | |
883 | error = kset_register(kset); | |
884 | if (error) { | |
885 | kfree(kset); | |
886 | return NULL; | |
887 | } | |
888 | return kset; | |
889 | } | |
890 | EXPORT_SYMBOL_GPL(kset_create_and_add); | |
891 | ||
892 | ||
893 | static DEFINE_SPINLOCK(kobj_ns_type_lock); | |
894 | static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES]; | |
895 | ||
896 | int kobj_ns_type_register(const struct kobj_ns_type_operations *ops) | |
897 | { | |
898 | enum kobj_ns_type type = ops->type; | |
899 | int error; | |
900 | ||
901 | spin_lock(&kobj_ns_type_lock); | |
902 | ||
903 | error = -EINVAL; | |
904 | if (type >= KOBJ_NS_TYPES) | |
905 | goto out; | |
906 | ||
907 | error = -EINVAL; | |
908 | if (type <= KOBJ_NS_TYPE_NONE) | |
909 | goto out; | |
910 | ||
911 | error = -EBUSY; | |
912 | if (kobj_ns_ops_tbl[type]) | |
913 | goto out; | |
914 | ||
915 | error = 0; | |
916 | kobj_ns_ops_tbl[type] = ops; | |
917 | ||
918 | out: | |
919 | spin_unlock(&kobj_ns_type_lock); | |
920 | return error; | |
921 | } | |
922 | ||
923 | int kobj_ns_type_registered(enum kobj_ns_type type) | |
924 | { | |
925 | int registered = 0; | |
926 | ||
927 | spin_lock(&kobj_ns_type_lock); | |
928 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES)) | |
929 | registered = kobj_ns_ops_tbl[type] != NULL; | |
930 | spin_unlock(&kobj_ns_type_lock); | |
931 | ||
932 | return registered; | |
933 | } | |
934 | ||
935 | const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent) | |
936 | { | |
937 | const struct kobj_ns_type_operations *ops = NULL; | |
938 | ||
939 | if (parent && parent->ktype->child_ns_type) | |
940 | ops = parent->ktype->child_ns_type(parent); | |
941 | ||
942 | return ops; | |
943 | } | |
944 | ||
945 | const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj) | |
946 | { | |
947 | return kobj_child_ns_ops(kobj->parent); | |
948 | } | |
949 | ||
950 | ||
951 | void *kobj_ns_grab_current(enum kobj_ns_type type) | |
952 | { | |
953 | void *ns = NULL; | |
954 | ||
955 | spin_lock(&kobj_ns_type_lock); | |
956 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
957 | kobj_ns_ops_tbl[type]) | |
958 | ns = kobj_ns_ops_tbl[type]->grab_current_ns(); | |
959 | spin_unlock(&kobj_ns_type_lock); | |
960 | ||
961 | return ns; | |
962 | } | |
963 | ||
964 | const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk) | |
965 | { | |
966 | const void *ns = NULL; | |
967 | ||
968 | spin_lock(&kobj_ns_type_lock); | |
969 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
970 | kobj_ns_ops_tbl[type]) | |
971 | ns = kobj_ns_ops_tbl[type]->netlink_ns(sk); | |
972 | spin_unlock(&kobj_ns_type_lock); | |
973 | ||
974 | return ns; | |
975 | } | |
976 | ||
977 | const void *kobj_ns_initial(enum kobj_ns_type type) | |
978 | { | |
979 | const void *ns = NULL; | |
980 | ||
981 | spin_lock(&kobj_ns_type_lock); | |
982 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
983 | kobj_ns_ops_tbl[type]) | |
984 | ns = kobj_ns_ops_tbl[type]->initial_ns(); | |
985 | spin_unlock(&kobj_ns_type_lock); | |
986 | ||
987 | return ns; | |
988 | } | |
989 | ||
990 | void kobj_ns_drop(enum kobj_ns_type type, void *ns) | |
991 | { | |
992 | spin_lock(&kobj_ns_type_lock); | |
993 | if ((type > KOBJ_NS_TYPE_NONE) && (type < KOBJ_NS_TYPES) && | |
994 | kobj_ns_ops_tbl[type] && kobj_ns_ops_tbl[type]->drop_ns) | |
995 | kobj_ns_ops_tbl[type]->drop_ns(ns); | |
996 | spin_unlock(&kobj_ns_type_lock); | |
997 | } | |
998 | ||
999 | EXPORT_SYMBOL(kobject_get); | |
1000 | EXPORT_SYMBOL(kobject_put); | |
1001 | EXPORT_SYMBOL(kobject_del); | |
1002 | ||
1003 | EXPORT_SYMBOL(kset_register); | |
1004 | EXPORT_SYMBOL(kset_unregister); |