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