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 */
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>
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;
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 }
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 }
61 static int get_kobj_path_length(struct kobject *kobj)
62 {
63 int length = 1;
64 struct kobject *parent = kobj;
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 }
79 static void fill_kobj_path(struct kobject *kobj, char *path, int length)
80 {
81 struct kobject *parent;
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 }
92 pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj),
93 kobj, __func__, path);
94 }
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;
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);
117 return path;
118 }
119 EXPORT_SYMBOL_GPL(kobject_get_path);
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;
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 }
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;
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 }
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 }
158 static int kobject_add_internal(struct kobject *kobj)
159 {
160 int error = 0;
161 struct kobject *parent;
163 if (!kobj)
164 return -ENOENT;
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 }
172 parent = kobject_get(kobj->parent);
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 }
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>");
187 error = create_dir(kobj);
188 if (error) {
189 kobj_kset_leave(kobj);
190 kobject_put(parent);
191 kobj->parent = NULL;
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;
206 return error;
207 }
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;
221 if (kobj->name && !fmt)
222 return 0;
224 kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs);
225 if (!kobj->name)
226 return -ENOMEM;
228 /* ewww... some of these buggers have '/' in the name ... */
229 while ((s = strchr(kobj->name, '/')))
230 s[0] = '!';
232 kfree(old_name);
233 return 0;
234 }
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;
250 va_start(vargs, fmt);
251 retval = kobject_set_name_vargs(kobj, fmt, vargs);
252 va_end(vargs);
254 return retval;
255 }
256 EXPORT_SYMBOL(kobject_set_name);
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;
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 }
289 kobject_init_internal(kobj);
290 kobj->ktype = ktype;
291 return;
293 error:
294 printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
295 dump_stack();
296 }
297 EXPORT_SYMBOL(kobject_init);
299 static int kobject_add_varg(struct kobject *kobj, struct kobject *parent,
300 const char *fmt, va_list vargs)
301 {
302 int retval;
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 }
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;
344 if (!kobj)
345 return -EINVAL;
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);
358 return retval;
359 }
360 EXPORT_SYMBOL(kobject_add);
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;
379 kobject_init(kobj, ktype);
381 va_start(args, fmt);
382 retval = kobject_add_varg(kobj, parent, fmt, args);
383 va_end(args);
385 return retval;
386 }
387 EXPORT_SYMBOL_GPL(kobject_init_and_add);
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];
407 kobj = kobject_get(kobj);
408 if (!kobj)
409 return -EINVAL;
410 if (!kobj->parent)
411 return -EINVAL;
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;
427 name = dup_name = kstrdup(new_name, GFP_KERNEL);
428 if (!name) {
429 error = -ENOMEM;
430 goto out;
431 }
433 error = sysfs_rename_dir(kobj, new_name);
434 if (error)
435 goto out;
437 /* Install the new kobject name */
438 dup_name = kobj->name;
439 kobj->name = name;
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);
446 out:
447 kfree(dup_name);
448 kfree(devpath_string);
449 kfree(devpath);
450 kobject_put(kobj);
452 return error;
453 }
454 EXPORT_SYMBOL_GPL(kobject_rename);
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];
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 }
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;
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 }
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 }
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;
543 pr_debug("kobject: '%s' (%p): %s\n",
544 kobject_name(kobj), kobj, __func__);
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);
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 }
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 }
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 }
571 /* free name if we allocated it */
572 if (name) {
573 pr_debug("kobject: '%s': free name\n", name);
574 kfree(name);
575 }
576 }
578 static void kobject_release(struct kref *kref)
579 {
580 kobject_cleanup(container_of(kref, struct kobject, kref));
581 }
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 }
600 static void dynamic_kobj_release(struct kobject *kobj)
601 {
602 pr_debug("kobject: (%p): %s\n", kobj, __func__);
603 kfree(kobj);
604 }
606 static struct kobj_type dynamic_kobj_ktype = {
607 .release = dynamic_kobj_release,
608 .sysfs_ops = &kobj_sysfs_ops,
609 };
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;
626 kobj = kzalloc(sizeof(*kobj), GFP_KERNEL);
627 if (!kobj)
628 return NULL;
630 kobject_init(kobj, &dynamic_kobj_ktype);
631 return kobj;
632 }
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;
652 kobj = kobject_create();
653 if (!kobj)
654 return NULL;
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);
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 }
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;
685 kattr = container_of(attr, struct kobj_attribute, attr);
686 if (kattr->show)
687 ret = kattr->show(kobj, kattr, buf);
688 return ret;
689 }
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;
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 }
703 const struct sysfs_ops kobj_sysfs_ops = {
704 .show = kobj_attr_show,
705 .store = kobj_attr_store,
706 };
708 /**
709 * kset_register - initialize and add a kset.
710 * @k: kset.
711 */
712 int kset_register(struct kset *k)
713 {
714 int err;
716 if (!k)
717 return -EINVAL;
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 }
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 }
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 }
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;
769 spin_lock(&kset->list_lock);
771 if (!hint)
772 goto slow_search;
774 /* end of list detection */
775 if (hint->entry.next == kset->list.next)
776 goto slow_search;
778 k = container_of(hint->entry.next, struct kobject, entry);
779 if (!kobject_name(k) || strcmp(kobject_name(k), name))
780 goto slow_search;
782 ret = kobject_get(k);
783 goto unlock_exit;
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 }
793 unlock_exit:
794 spin_unlock(&kset->list_lock);
796 if (hint)
797 kobject_put(hint);
799 return ret;
800 }
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 }
810 static struct kobj_type kset_ktype = {
811 .sysfs_ops = &kobj_sysfs_ops,
812 .release = kset_release,
813 };
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;
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;
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;
856 return kset;
857 }
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;
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);
893 static DEFINE_SPINLOCK(kobj_ns_type_lock);
894 static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
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;
901 spin_lock(&kobj_ns_type_lock);
903 error = -EINVAL;
904 if (type >= KOBJ_NS_TYPES)
905 goto out;
907 error = -EINVAL;
908 if (type <= KOBJ_NS_TYPE_NONE)
909 goto out;
911 error = -EBUSY;
912 if (kobj_ns_ops_tbl[type])
913 goto out;
915 error = 0;
916 kobj_ns_ops_tbl[type] = ops;
918 out:
919 spin_unlock(&kobj_ns_type_lock);
920 return error;
921 }
923 int kobj_ns_type_registered(enum kobj_ns_type type)
924 {
925 int registered = 0;
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);
932 return registered;
933 }
935 const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent)
936 {
937 const struct kobj_ns_type_operations *ops = NULL;
939 if (parent && parent->ktype->child_ns_type)
940 ops = parent->ktype->child_ns_type(parent);
942 return ops;
943 }
945 const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
946 {
947 return kobj_child_ns_ops(kobj->parent);
948 }
951 void *kobj_ns_grab_current(enum kobj_ns_type type)
952 {
953 void *ns = NULL;
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);
961 return ns;
962 }
964 const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk)
965 {
966 const void *ns = NULL;
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);
974 return ns;
975 }
977 const void *kobj_ns_initial(enum kobj_ns_type type)
978 {
979 const void *ns = NULL;
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);
987 return ns;
988 }
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 }
999 EXPORT_SYMBOL(kobject_get);
1000 EXPORT_SYMBOL(kobject_put);
1001 EXPORT_SYMBOL(kobject_del);
1003 EXPORT_SYMBOL(kset_register);
1004 EXPORT_SYMBOL(kset_unregister);