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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * fs/sysfs/group.c - Operations for adding/removing multiple files at once.
4 *
5 * Copyright (c) 2003 Patrick Mochel
6 * Copyright (c) 2003 Open Source Development Lab
7 * Copyright (c) 2013 Greg Kroah-Hartman
8 * Copyright (c) 2013 The Linux Foundation
9 */
10
11#include <linux/kobject.h>
12#include <linux/module.h>
13#include <linux/dcache.h>
14#include <linux/namei.h>
15#include <linux/err.h>
16#include <linux/fs.h>
17#include "sysfs.h"
18
19
20static void remove_files(struct kernfs_node *parent,
21 const struct attribute_group *grp)
22{
23 struct attribute *const *attr;
24 struct bin_attribute *const *bin_attr;
25
26 if (grp->attrs)
27 for (attr = grp->attrs; *attr; attr++)
28 kernfs_remove_by_name(parent, (*attr)->name);
29 if (grp->bin_attrs)
30 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
31 kernfs_remove_by_name(parent, (*bin_attr)->attr.name);
32}
33
34static int create_files(struct kernfs_node *parent, struct kobject *kobj,
35 kuid_t uid, kgid_t gid,
36 const struct attribute_group *grp, int update)
37{
38 struct attribute *const *attr;
39 struct bin_attribute *const *bin_attr;
40 int error = 0, i;
41
42 if (grp->attrs) {
43 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
44 umode_t mode = (*attr)->mode;
45
46 /*
47 * In update mode, we're changing the permissions or
48 * visibility. Do this by first removing then
49 * re-adding (if required) the file.
50 */
51 if (update)
52 kernfs_remove_by_name(parent, (*attr)->name);
53 if (grp->is_visible) {
54 mode = grp->is_visible(kobj, *attr, i);
55 if (!mode)
56 continue;
57 }
58
59 WARN(mode & ~(SYSFS_PREALLOC | 0664),
60 "Attribute %s: Invalid permissions 0%o\n",
61 (*attr)->name, mode);
62
63 mode &= SYSFS_PREALLOC | 0664;
64 error = sysfs_add_file_mode_ns(parent, *attr, false,
65 mode, uid, gid, NULL);
66 if (unlikely(error))
67 break;
68 }
69 if (error) {
70 remove_files(parent, grp);
71 goto exit;
72 }
73 }
74
75 if (grp->bin_attrs) {
76 for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) {
77 umode_t mode = (*bin_attr)->attr.mode;
78
79 if (update)
80 kernfs_remove_by_name(parent,
81 (*bin_attr)->attr.name);
82 if (grp->is_bin_visible) {
83 mode = grp->is_bin_visible(kobj, *bin_attr, i);
84 if (!mode)
85 continue;
86 }
87
88 WARN(mode & ~(SYSFS_PREALLOC | 0664),
89 "Attribute %s: Invalid permissions 0%o\n",
90 (*bin_attr)->attr.name, mode);
91
92 mode &= SYSFS_PREALLOC | 0664;
93 error = sysfs_add_file_mode_ns(parent,
94 &(*bin_attr)->attr, true,
95 mode,
96 uid, gid, NULL);
97 if (error)
98 break;
99 }
100 if (error)
101 remove_files(parent, grp);
102 }
103exit:
104 return error;
105}
106
107
108static int internal_create_group(struct kobject *kobj, int update,
109 const struct attribute_group *grp)
110{
111 struct kernfs_node *kn;
112 kuid_t uid;
113 kgid_t gid;
114 int error;
115
116 if (WARN_ON(!kobj || (!update && !kobj->sd)))
117 return -EINVAL;
118
119 /* Updates may happen before the object has been instantiated */
120 if (unlikely(update && !kobj->sd))
121 return -EINVAL;
122 if (!grp->attrs && !grp->bin_attrs) {
123 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
124 kobj->name, grp->name ?: "");
125 return -EINVAL;
126 }
127 kobject_get_ownership(kobj, &uid, &gid);
128 if (grp->name) {
129 if (update) {
130 kn = kernfs_find_and_get(kobj->sd, grp->name);
131 if (!kn) {
132 pr_warn("Can't update unknown attr grp name: %s/%s\n",
133 kobj->name, grp->name);
134 return -EINVAL;
135 }
136 } else {
137 kn = kernfs_create_dir_ns(kobj->sd, grp->name,
138 S_IRWXU | S_IRUGO | S_IXUGO,
139 uid, gid, kobj, NULL);
140 if (IS_ERR(kn)) {
141 if (PTR_ERR(kn) == -EEXIST)
142 sysfs_warn_dup(kobj->sd, grp->name);
143 return PTR_ERR(kn);
144 }
145 }
146 } else
147 kn = kobj->sd;
148 kernfs_get(kn);
149 error = create_files(kn, kobj, uid, gid, grp, update);
150 if (error) {
151 if (grp->name)
152 kernfs_remove(kn);
153 }
154 kernfs_put(kn);
155
156 if (grp->name && update)
157 kernfs_put(kn);
158
159 return error;
160}
161
162/**
163 * sysfs_create_group - given a directory kobject, create an attribute group
164 * @kobj: The kobject to create the group on
165 * @grp: The attribute group to create
166 *
167 * This function creates a group for the first time. It will explicitly
168 * warn and error if any of the attribute files being created already exist.
169 *
170 * Returns 0 on success or error code on failure.
171 */
172int sysfs_create_group(struct kobject *kobj,
173 const struct attribute_group *grp)
174{
175 return internal_create_group(kobj, 0, grp);
176}
177EXPORT_SYMBOL_GPL(sysfs_create_group);
178
179static int internal_create_groups(struct kobject *kobj, int update,
180 const struct attribute_group **groups)
181{
182 int error = 0;
183 int i;
184
185 if (!groups)
186 return 0;
187
188 for (i = 0; groups[i]; i++) {
189 error = internal_create_group(kobj, update, groups[i]);
190 if (error) {
191 while (--i >= 0)
192 sysfs_remove_group(kobj, groups[i]);
193 break;
194 }
195 }
196 return error;
197}
198
199/**
200 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
201 * @kobj: The kobject to create the group on
202 * @groups: The attribute groups to create, NULL terminated
203 *
204 * This function creates a bunch of attribute groups. If an error occurs when
205 * creating a group, all previously created groups will be removed, unwinding
206 * everything back to the original state when this function was called.
207 * It will explicitly warn and error if any of the attribute files being
208 * created already exist.
209 *
210 * Returns 0 on success or error code from sysfs_create_group on failure.
211 */
212int sysfs_create_groups(struct kobject *kobj,
213 const struct attribute_group **groups)
214{
215 return internal_create_groups(kobj, 0, groups);
216}
217EXPORT_SYMBOL_GPL(sysfs_create_groups);
218
219/**
220 * sysfs_update_groups - given a directory kobject, create a bunch of attribute groups
221 * @kobj: The kobject to update the group on
222 * @groups: The attribute groups to update, NULL terminated
223 *
224 * This function update a bunch of attribute groups. If an error occurs when
225 * updating a group, all previously updated groups will be removed together
226 * with already existing (not updated) attributes.
227 *
228 * Returns 0 on success or error code from sysfs_update_group on failure.
229 */
230int sysfs_update_groups(struct kobject *kobj,
231 const struct attribute_group **groups)
232{
233 return internal_create_groups(kobj, 1, groups);
234}
235EXPORT_SYMBOL_GPL(sysfs_update_groups);
236
237/**
238 * sysfs_update_group - given a directory kobject, update an attribute group
239 * @kobj: The kobject to update the group on
240 * @grp: The attribute group to update
241 *
242 * This function updates an attribute group. Unlike
243 * sysfs_create_group(), it will explicitly not warn or error if any
244 * of the attribute files being created already exist. Furthermore,
245 * if the visibility of the files has changed through the is_visible()
246 * callback, it will update the permissions and add or remove the
247 * relevant files. Changing a group's name (subdirectory name under
248 * kobj's directory in sysfs) is not allowed.
249 *
250 * The primary use for this function is to call it after making a change
251 * that affects group visibility.
252 *
253 * Returns 0 on success or error code on failure.
254 */
255int sysfs_update_group(struct kobject *kobj,
256 const struct attribute_group *grp)
257{
258 return internal_create_group(kobj, 1, grp);
259}
260EXPORT_SYMBOL_GPL(sysfs_update_group);
261
262/**
263 * sysfs_remove_group: remove a group from a kobject
264 * @kobj: kobject to remove the group from
265 * @grp: group to remove
266 *
267 * This function removes a group of attributes from a kobject. The attributes
268 * previously have to have been created for this group, otherwise it will fail.
269 */
270void sysfs_remove_group(struct kobject *kobj,
271 const struct attribute_group *grp)
272{
273 struct kernfs_node *parent = kobj->sd;
274 struct kernfs_node *kn;
275
276 if (grp->name) {
277 kn = kernfs_find_and_get(parent, grp->name);
278 if (!kn) {
279 WARN(!kn, KERN_WARNING
280 "sysfs group '%s' not found for kobject '%s'\n",
281 grp->name, kobject_name(kobj));
282 return;
283 }
284 } else {
285 kn = parent;
286 kernfs_get(kn);
287 }
288
289 remove_files(kn, grp);
290 if (grp->name)
291 kernfs_remove(kn);
292
293 kernfs_put(kn);
294}
295EXPORT_SYMBOL_GPL(sysfs_remove_group);
296
297/**
298 * sysfs_remove_groups - remove a list of groups
299 *
300 * @kobj: The kobject for the groups to be removed from
301 * @groups: NULL terminated list of groups to be removed
302 *
303 * If groups is not NULL, remove the specified groups from the kobject.
304 */
305void sysfs_remove_groups(struct kobject *kobj,
306 const struct attribute_group **groups)
307{
308 int i;
309
310 if (!groups)
311 return;
312 for (i = 0; groups[i]; i++)
313 sysfs_remove_group(kobj, groups[i]);
314}
315EXPORT_SYMBOL_GPL(sysfs_remove_groups);
316
317/**
318 * sysfs_merge_group - merge files into a pre-existing attribute group.
319 * @kobj: The kobject containing the group.
320 * @grp: The files to create and the attribute group they belong to.
321 *
322 * This function returns an error if the group doesn't exist or any of the
323 * files already exist in that group, in which case none of the new files
324 * are created.
325 */
326int sysfs_merge_group(struct kobject *kobj,
327 const struct attribute_group *grp)
328{
329 struct kernfs_node *parent;
330 kuid_t uid;
331 kgid_t gid;
332 int error = 0;
333 struct attribute *const *attr;
334 int i;
335
336 parent = kernfs_find_and_get(kobj->sd, grp->name);
337 if (!parent)
338 return -ENOENT;
339
340 kobject_get_ownership(kobj, &uid, &gid);
341
342 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
343 error = sysfs_add_file_mode_ns(parent, *attr, false,
344 (*attr)->mode, uid, gid, NULL);
345 if (error) {
346 while (--i >= 0)
347 kernfs_remove_by_name(parent, (*--attr)->name);
348 }
349 kernfs_put(parent);
350
351 return error;
352}
353EXPORT_SYMBOL_GPL(sysfs_merge_group);
354
355/**
356 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
357 * @kobj: The kobject containing the group.
358 * @grp: The files to remove and the attribute group they belong to.
359 */
360void sysfs_unmerge_group(struct kobject *kobj,
361 const struct attribute_group *grp)
362{
363 struct kernfs_node *parent;
364 struct attribute *const *attr;
365
366 parent = kernfs_find_and_get(kobj->sd, grp->name);
367 if (parent) {
368 for (attr = grp->attrs; *attr; ++attr)
369 kernfs_remove_by_name(parent, (*attr)->name);
370 kernfs_put(parent);
371 }
372}
373EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
374
375/**
376 * sysfs_add_link_to_group - add a symlink to an attribute group.
377 * @kobj: The kobject containing the group.
378 * @group_name: The name of the group.
379 * @target: The target kobject of the symlink to create.
380 * @link_name: The name of the symlink to create.
381 */
382int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
383 struct kobject *target, const char *link_name)
384{
385 struct kernfs_node *parent;
386 int error = 0;
387
388 parent = kernfs_find_and_get(kobj->sd, group_name);
389 if (!parent)
390 return -ENOENT;
391
392 error = sysfs_create_link_sd(parent, target, link_name);
393 kernfs_put(parent);
394
395 return error;
396}
397EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
398
399/**
400 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
401 * @kobj: The kobject containing the group.
402 * @group_name: The name of the group.
403 * @link_name: The name of the symlink to remove.
404 */
405void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
406 const char *link_name)
407{
408 struct kernfs_node *parent;
409
410 parent = kernfs_find_and_get(kobj->sd, group_name);
411 if (parent) {
412 kernfs_remove_by_name(parent, link_name);
413 kernfs_put(parent);
414 }
415}
416EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
417
418/**
419 * compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
420 * to a group or an attribute
421 * @kobj: The kobject containing the group.
422 * @target_kobj: The target kobject.
423 * @target_name: The name of the target group or attribute.
424 * @symlink_name: The name of the symlink file (target_name will be
425 * considered if symlink_name is NULL).
426 */
427int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
428 struct kobject *target_kobj,
429 const char *target_name,
430 const char *symlink_name)
431{
432 struct kernfs_node *target;
433 struct kernfs_node *entry;
434 struct kernfs_node *link;
435
436 /*
437 * We don't own @target_kobj and it may be removed at any time.
438 * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
439 * for details.
440 */
441 spin_lock(&sysfs_symlink_target_lock);
442 target = target_kobj->sd;
443 if (target)
444 kernfs_get(target);
445 spin_unlock(&sysfs_symlink_target_lock);
446 if (!target)
447 return -ENOENT;
448
449 entry = kernfs_find_and_get(target_kobj->sd, target_name);
450 if (!entry) {
451 kernfs_put(target);
452 return -ENOENT;
453 }
454
455 if (!symlink_name)
456 symlink_name = target_name;
457
458 link = kernfs_create_link(kobj->sd, symlink_name, entry);
459 if (PTR_ERR(link) == -EEXIST)
460 sysfs_warn_dup(kobj->sd, symlink_name);
461
462 kernfs_put(entry);
463 kernfs_put(target);
464 return PTR_ERR_OR_ZERO(link);
465}
466EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj);
467
468static int sysfs_group_attrs_change_owner(struct kernfs_node *grp_kn,
469 const struct attribute_group *grp,
470 struct iattr *newattrs)
471{
472 struct kernfs_node *kn;
473 int error;
474
475 if (grp->attrs) {
476 struct attribute *const *attr;
477
478 for (attr = grp->attrs; *attr; attr++) {
479 kn = kernfs_find_and_get(grp_kn, (*attr)->name);
480 if (!kn)
481 return -ENOENT;
482
483 error = kernfs_setattr(kn, newattrs);
484 kernfs_put(kn);
485 if (error)
486 return error;
487 }
488 }
489
490 if (grp->bin_attrs) {
491 struct bin_attribute *const *bin_attr;
492
493 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
494 kn = kernfs_find_and_get(grp_kn, (*bin_attr)->attr.name);
495 if (!kn)
496 return -ENOENT;
497
498 error = kernfs_setattr(kn, newattrs);
499 kernfs_put(kn);
500 if (error)
501 return error;
502 }
503 }
504
505 return 0;
506}
507
508/**
509 * sysfs_group_change_owner - change owner of an attribute group.
510 * @kobj: The kobject containing the group.
511 * @grp: The attribute group.
512 * @kuid: new owner's kuid
513 * @kgid: new owner's kgid
514 *
515 * Returns 0 on success or error code on failure.
516 */
517int sysfs_group_change_owner(struct kobject *kobj,
518 const struct attribute_group *grp, kuid_t kuid,
519 kgid_t kgid)
520{
521 struct kernfs_node *grp_kn;
522 int error;
523 struct iattr newattrs = {
524 .ia_valid = ATTR_UID | ATTR_GID,
525 .ia_uid = kuid,
526 .ia_gid = kgid,
527 };
528
529 if (!kobj->state_in_sysfs)
530 return -EINVAL;
531
532 if (grp->name) {
533 grp_kn = kernfs_find_and_get(kobj->sd, grp->name);
534 } else {
535 kernfs_get(kobj->sd);
536 grp_kn = kobj->sd;
537 }
538 if (!grp_kn)
539 return -ENOENT;
540
541 error = kernfs_setattr(grp_kn, &newattrs);
542 if (!error)
543 error = sysfs_group_attrs_change_owner(grp_kn, grp, &newattrs);
544
545 kernfs_put(grp_kn);
546
547 return error;
548}
549EXPORT_SYMBOL_GPL(sysfs_group_change_owner);
550
551/**
552 * sysfs_groups_change_owner - change owner of a set of attribute groups.
553 * @kobj: The kobject containing the groups.
554 * @groups: The attribute groups.
555 * @kuid: new owner's kuid
556 * @kgid: new owner's kgid
557 *
558 * Returns 0 on success or error code on failure.
559 */
560int sysfs_groups_change_owner(struct kobject *kobj,
561 const struct attribute_group **groups,
562 kuid_t kuid, kgid_t kgid)
563{
564 int error = 0, i;
565
566 if (!kobj->state_in_sysfs)
567 return -EINVAL;
568
569 if (!groups)
570 return 0;
571
572 for (i = 0; groups[i]; i++) {
573 error = sysfs_group_change_owner(kobj, groups[i], kuid, kgid);
574 if (error)
575 break;
576 }
577
578 return error;
579}
580EXPORT_SYMBOL_GPL(sysfs_groups_change_owner);
1/*
2 * fs/sysfs/group.c - Operations for adding/removing multiple files at once.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2013 Greg Kroah-Hartman
7 * Copyright (c) 2013 The Linux Foundation
8 *
9 * This file is released undert the GPL v2.
10 *
11 */
12
13#include <linux/kobject.h>
14#include <linux/module.h>
15#include <linux/dcache.h>
16#include <linux/namei.h>
17#include <linux/err.h>
18#include "sysfs.h"
19
20
21static void remove_files(struct kernfs_node *parent, struct kobject *kobj,
22 const struct attribute_group *grp)
23{
24 struct attribute *const *attr;
25 struct bin_attribute *const *bin_attr;
26
27 if (grp->attrs)
28 for (attr = grp->attrs; *attr; attr++)
29 kernfs_remove_by_name(parent, (*attr)->name);
30 if (grp->bin_attrs)
31 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
32 sysfs_remove_bin_file(kobj, *bin_attr);
33}
34
35static int create_files(struct kernfs_node *parent, struct kobject *kobj,
36 const struct attribute_group *grp, int update)
37{
38 struct attribute *const *attr;
39 struct bin_attribute *const *bin_attr;
40 int error = 0, i;
41
42 if (grp->attrs) {
43 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
44 umode_t mode = 0;
45
46 /*
47 * In update mode, we're changing the permissions or
48 * visibility. Do this by first removing then
49 * re-adding (if required) the file.
50 */
51 if (update)
52 kernfs_remove_by_name(parent, (*attr)->name);
53 if (grp->is_visible) {
54 mode = grp->is_visible(kobj, *attr, i);
55 if (!mode)
56 continue;
57 }
58 error = sysfs_add_file_mode_ns(parent, *attr, false,
59 (*attr)->mode | mode,
60 NULL);
61 if (unlikely(error))
62 break;
63 }
64 if (error) {
65 remove_files(parent, kobj, grp);
66 goto exit;
67 }
68 }
69
70 if (grp->bin_attrs) {
71 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
72 if (update)
73 kernfs_remove_by_name(parent,
74 (*bin_attr)->attr.name);
75 error = sysfs_add_file_mode_ns(parent,
76 &(*bin_attr)->attr, true,
77 (*bin_attr)->attr.mode, NULL);
78 if (error)
79 break;
80 }
81 if (error)
82 remove_files(parent, kobj, grp);
83 }
84exit:
85 return error;
86}
87
88
89static int internal_create_group(struct kobject *kobj, int update,
90 const struct attribute_group *grp)
91{
92 struct kernfs_node *kn;
93 int error;
94
95 BUG_ON(!kobj || (!update && !kobj->sd));
96
97 /* Updates may happen before the object has been instantiated */
98 if (unlikely(update && !kobj->sd))
99 return -EINVAL;
100 if (!grp->attrs && !grp->bin_attrs) {
101 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
102 kobj->name, grp->name ? "" : grp->name);
103 return -EINVAL;
104 }
105 if (grp->name) {
106 kn = kernfs_create_dir(kobj->sd, grp->name,
107 S_IRWXU | S_IRUGO | S_IXUGO, kobj);
108 if (IS_ERR(kn)) {
109 if (PTR_ERR(kn) == -EEXIST)
110 sysfs_warn_dup(kobj->sd, grp->name);
111 return PTR_ERR(kn);
112 }
113 } else
114 kn = kobj->sd;
115 kernfs_get(kn);
116 error = create_files(kn, kobj, grp, update);
117 if (error) {
118 if (grp->name)
119 kernfs_remove(kn);
120 }
121 kernfs_put(kn);
122 return error;
123}
124
125/**
126 * sysfs_create_group - given a directory kobject, create an attribute group
127 * @kobj: The kobject to create the group on
128 * @grp: The attribute group to create
129 *
130 * This function creates a group for the first time. It will explicitly
131 * warn and error if any of the attribute files being created already exist.
132 *
133 * Returns 0 on success or error.
134 */
135int sysfs_create_group(struct kobject *kobj,
136 const struct attribute_group *grp)
137{
138 return internal_create_group(kobj, 0, grp);
139}
140EXPORT_SYMBOL_GPL(sysfs_create_group);
141
142/**
143 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
144 * @kobj: The kobject to create the group on
145 * @groups: The attribute groups to create, NULL terminated
146 *
147 * This function creates a bunch of attribute groups. If an error occurs when
148 * creating a group, all previously created groups will be removed, unwinding
149 * everything back to the original state when this function was called.
150 * It will explicitly warn and error if any of the attribute files being
151 * created already exist.
152 *
153 * Returns 0 on success or error code from sysfs_create_group on error.
154 */
155int sysfs_create_groups(struct kobject *kobj,
156 const struct attribute_group **groups)
157{
158 int error = 0;
159 int i;
160
161 if (!groups)
162 return 0;
163
164 for (i = 0; groups[i]; i++) {
165 error = sysfs_create_group(kobj, groups[i]);
166 if (error) {
167 while (--i >= 0)
168 sysfs_remove_group(kobj, groups[i]);
169 break;
170 }
171 }
172 return error;
173}
174EXPORT_SYMBOL_GPL(sysfs_create_groups);
175
176/**
177 * sysfs_update_group - given a directory kobject, update an attribute group
178 * @kobj: The kobject to update the group on
179 * @grp: The attribute group to update
180 *
181 * This function updates an attribute group. Unlike
182 * sysfs_create_group(), it will explicitly not warn or error if any
183 * of the attribute files being created already exist. Furthermore,
184 * if the visibility of the files has changed through the is_visible()
185 * callback, it will update the permissions and add or remove the
186 * relevant files.
187 *
188 * The primary use for this function is to call it after making a change
189 * that affects group visibility.
190 *
191 * Returns 0 on success or error.
192 */
193int sysfs_update_group(struct kobject *kobj,
194 const struct attribute_group *grp)
195{
196 return internal_create_group(kobj, 1, grp);
197}
198EXPORT_SYMBOL_GPL(sysfs_update_group);
199
200/**
201 * sysfs_remove_group: remove a group from a kobject
202 * @kobj: kobject to remove the group from
203 * @grp: group to remove
204 *
205 * This function removes a group of attributes from a kobject. The attributes
206 * previously have to have been created for this group, otherwise it will fail.
207 */
208void sysfs_remove_group(struct kobject *kobj,
209 const struct attribute_group *grp)
210{
211 struct kernfs_node *parent = kobj->sd;
212 struct kernfs_node *kn;
213
214 if (grp->name) {
215 kn = kernfs_find_and_get(parent, grp->name);
216 if (!kn) {
217 WARN(!kn, KERN_WARNING
218 "sysfs group %p not found for kobject '%s'\n",
219 grp, kobject_name(kobj));
220 return;
221 }
222 } else {
223 kn = parent;
224 kernfs_get(kn);
225 }
226
227 remove_files(kn, kobj, grp);
228 if (grp->name)
229 kernfs_remove(kn);
230
231 kernfs_put(kn);
232}
233EXPORT_SYMBOL_GPL(sysfs_remove_group);
234
235/**
236 * sysfs_remove_groups - remove a list of groups
237 *
238 * @kobj: The kobject for the groups to be removed from
239 * @groups: NULL terminated list of groups to be removed
240 *
241 * If groups is not NULL, remove the specified groups from the kobject.
242 */
243void sysfs_remove_groups(struct kobject *kobj,
244 const struct attribute_group **groups)
245{
246 int i;
247
248 if (!groups)
249 return;
250 for (i = 0; groups[i]; i++)
251 sysfs_remove_group(kobj, groups[i]);
252}
253EXPORT_SYMBOL_GPL(sysfs_remove_groups);
254
255/**
256 * sysfs_merge_group - merge files into a pre-existing attribute group.
257 * @kobj: The kobject containing the group.
258 * @grp: The files to create and the attribute group they belong to.
259 *
260 * This function returns an error if the group doesn't exist or any of the
261 * files already exist in that group, in which case none of the new files
262 * are created.
263 */
264int sysfs_merge_group(struct kobject *kobj,
265 const struct attribute_group *grp)
266{
267 struct kernfs_node *parent;
268 int error = 0;
269 struct attribute *const *attr;
270 int i;
271
272 parent = kernfs_find_and_get(kobj->sd, grp->name);
273 if (!parent)
274 return -ENOENT;
275
276 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
277 error = sysfs_add_file(parent, *attr, false);
278 if (error) {
279 while (--i >= 0)
280 kernfs_remove_by_name(parent, (*--attr)->name);
281 }
282 kernfs_put(parent);
283
284 return error;
285}
286EXPORT_SYMBOL_GPL(sysfs_merge_group);
287
288/**
289 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
290 * @kobj: The kobject containing the group.
291 * @grp: The files to remove and the attribute group they belong to.
292 */
293void sysfs_unmerge_group(struct kobject *kobj,
294 const struct attribute_group *grp)
295{
296 struct kernfs_node *parent;
297 struct attribute *const *attr;
298
299 parent = kernfs_find_and_get(kobj->sd, grp->name);
300 if (parent) {
301 for (attr = grp->attrs; *attr; ++attr)
302 kernfs_remove_by_name(parent, (*attr)->name);
303 kernfs_put(parent);
304 }
305}
306EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
307
308/**
309 * sysfs_add_link_to_group - add a symlink to an attribute group.
310 * @kobj: The kobject containing the group.
311 * @group_name: The name of the group.
312 * @target: The target kobject of the symlink to create.
313 * @link_name: The name of the symlink to create.
314 */
315int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
316 struct kobject *target, const char *link_name)
317{
318 struct kernfs_node *parent;
319 int error = 0;
320
321 parent = kernfs_find_and_get(kobj->sd, group_name);
322 if (!parent)
323 return -ENOENT;
324
325 error = sysfs_create_link_sd(parent, target, link_name);
326 kernfs_put(parent);
327
328 return error;
329}
330EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
331
332/**
333 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
334 * @kobj: The kobject containing the group.
335 * @group_name: The name of the group.
336 * @link_name: The name of the symlink to remove.
337 */
338void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
339 const char *link_name)
340{
341 struct kernfs_node *parent;
342
343 parent = kernfs_find_and_get(kobj->sd, group_name);
344 if (parent) {
345 kernfs_remove_by_name(parent, link_name);
346 kernfs_put(parent);
347 }
348}
349EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);