projects/linux·blob v3.5-rc4 · refs

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1/*
2 * kobject.c - library routines for handling generic kernel objects
3 *
4 * Copyright (c) 2002-2003 Patrick Mochel <[email protected]>
5 * Copyright (c) 2006-2007 Greg Kroah-Hartman <[email protected]>
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 */
30static 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
47static 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
59static 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
77static 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 */
102char *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}
117EXPORT_SYMBOL_GPL(kobject_get_path);
118
119/* add the kobject to its kset's list */
120static 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 */
132static 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
143static 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
156static 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 */
213int 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 */
243int 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}
254EXPORT_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 */
268void 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
291error:
292 printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str);
293 dump_stack();
294}
295EXPORT_SYMBOL(kobject_init);
296
297static 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 */
336int 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}
358EXPORT_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 */
371int 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}
385EXPORT_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 */
397int 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
444out:
445 kfree(dup_name);
446 kfree(devpath_string);
447 kfree(devpath);
448 kobject_put(kobj);
449
450 return error;
451}
452EXPORT_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 */
459int 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);
497out:
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 */
509void 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 */
525struct 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 */
536static 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
576static 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 */
587void 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
598static void dynamic_kobj_release(struct kobject *kobj)
599{
600 pr_debug("kobject: (%p): %s\n", kobj, __func__);
601 kfree(kobj);
602}
603
604static 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 */
620struct 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 */
645struct 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}
663EXPORT_SYMBOL_GPL(kobject_create_and_add);
664
665/**
666 * kset_init - initialize a kset for use
667 * @k: kset
668 */
669void 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 */
677static 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
689static 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
701const 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 */
710int 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 */
729void 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 */
745struct 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
763static 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
771static 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 */
791static 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 */
834struct 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}
851EXPORT_SYMBOL_GPL(kset_create_and_add);
852
853
854static DEFINE_SPINLOCK(kobj_ns_type_lock);
855static const struct kobj_ns_type_operations *kobj_ns_ops_tbl[KOBJ_NS_TYPES];
856
857int 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
879out:
880 spin_unlock(&kobj_ns_type_lock);
881 return error;
882}
883
884int 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
896const 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
906const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj)
907{
908 return kobj_child_ns_ops(kobj->parent);
909}
910
911
912void *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
925const 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
938const 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
951void 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
960EXPORT_SYMBOL(kobject_get);
961EXPORT_SYMBOL(kobject_put);
962EXPORT_SYMBOL(kobject_del);
963
964EXPORT_SYMBOL(kset_register);
965EXPORT_SYMBOL(kset_unregister);