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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, mode, uid,
65 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_bin_file_mode_ns(parent, *bin_attr,
94 mode, uid, gid,
95 NULL);
96 if (error)
97 break;
98 }
99 if (error)
100 remove_files(parent, grp);
101 }
102exit:
103 return error;
104}
105
106
107static int internal_create_group(struct kobject *kobj, int update,
108 const struct attribute_group *grp)
109{
110 struct kernfs_node *kn;
111 kuid_t uid;
112 kgid_t gid;
113 int error;
114
115 if (WARN_ON(!kobj || (!update && !kobj->sd)))
116 return -EINVAL;
117
118 /* Updates may happen before the object has been instantiated */
119 if (unlikely(update && !kobj->sd))
120 return -EINVAL;
121
122 if (!grp->attrs && !grp->bin_attrs) {
123 pr_debug("sysfs: (bin_)attrs not set by subsystem for group: %s/%s, skipping\n",
124 kobj->name, grp->name ?: "");
125 return 0;
126 }
127
128 kobject_get_ownership(kobj, &uid, &gid);
129 if (grp->name) {
130 if (update) {
131 kn = kernfs_find_and_get(kobj->sd, grp->name);
132 if (!kn) {
133 pr_warn("Can't update unknown attr grp name: %s/%s\n",
134 kobj->name, grp->name);
135 return -EINVAL;
136 }
137 } else {
138 kn = kernfs_create_dir_ns(kobj->sd, grp->name,
139 S_IRWXU | S_IRUGO | S_IXUGO,
140 uid, gid, kobj, NULL);
141 if (IS_ERR(kn)) {
142 if (PTR_ERR(kn) == -EEXIST)
143 sysfs_warn_dup(kobj->sd, grp->name);
144 return PTR_ERR(kn);
145 }
146 }
147 } else {
148 kn = kobj->sd;
149 }
150
151 kernfs_get(kn);
152 error = create_files(kn, kobj, uid, gid, grp, update);
153 if (error) {
154 if (grp->name)
155 kernfs_remove(kn);
156 }
157 kernfs_put(kn);
158
159 if (grp->name && update)
160 kernfs_put(kn);
161
162 return error;
163}
164
165/**
166 * sysfs_create_group - given a directory kobject, create an attribute group
167 * @kobj: The kobject to create the group on
168 * @grp: The attribute group to create
169 *
170 * This function creates a group for the first time. It will explicitly
171 * warn and error if any of the attribute files being created already exist.
172 *
173 * Returns 0 on success or error code on failure.
174 */
175int sysfs_create_group(struct kobject *kobj,
176 const struct attribute_group *grp)
177{
178 return internal_create_group(kobj, 0, grp);
179}
180EXPORT_SYMBOL_GPL(sysfs_create_group);
181
182static int internal_create_groups(struct kobject *kobj, int update,
183 const struct attribute_group **groups)
184{
185 int error = 0;
186 int i;
187
188 if (!groups)
189 return 0;
190
191 for (i = 0; groups[i]; i++) {
192 error = internal_create_group(kobj, update, groups[i]);
193 if (error) {
194 while (--i >= 0)
195 sysfs_remove_group(kobj, groups[i]);
196 break;
197 }
198 }
199 return error;
200}
201
202/**
203 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
204 * @kobj: The kobject to create the group on
205 * @groups: The attribute groups to create, NULL terminated
206 *
207 * This function creates a bunch of attribute groups. If an error occurs when
208 * creating a group, all previously created groups will be removed, unwinding
209 * everything back to the original state when this function was called.
210 * It will explicitly warn and error if any of the attribute files being
211 * created already exist.
212 *
213 * Returns 0 on success or error code from sysfs_create_group on failure.
214 */
215int sysfs_create_groups(struct kobject *kobj,
216 const struct attribute_group **groups)
217{
218 return internal_create_groups(kobj, 0, groups);
219}
220EXPORT_SYMBOL_GPL(sysfs_create_groups);
221
222/**
223 * sysfs_update_groups - given a directory kobject, create a bunch of attribute groups
224 * @kobj: The kobject to update the group on
225 * @groups: The attribute groups to update, NULL terminated
226 *
227 * This function update a bunch of attribute groups. If an error occurs when
228 * updating a group, all previously updated groups will be removed together
229 * with already existing (not updated) attributes.
230 *
231 * Returns 0 on success or error code from sysfs_update_group on failure.
232 */
233int sysfs_update_groups(struct kobject *kobj,
234 const struct attribute_group **groups)
235{
236 return internal_create_groups(kobj, 1, groups);
237}
238EXPORT_SYMBOL_GPL(sysfs_update_groups);
239
240/**
241 * sysfs_update_group - given a directory kobject, update an attribute group
242 * @kobj: The kobject to update the group on
243 * @grp: The attribute group to update
244 *
245 * This function updates an attribute group. Unlike
246 * sysfs_create_group(), it will explicitly not warn or error if any
247 * of the attribute files being created already exist. Furthermore,
248 * if the visibility of the files has changed through the is_visible()
249 * callback, it will update the permissions and add or remove the
250 * relevant files. Changing a group's name (subdirectory name under
251 * kobj's directory in sysfs) is not allowed.
252 *
253 * The primary use for this function is to call it after making a change
254 * that affects group visibility.
255 *
256 * Returns 0 on success or error code on failure.
257 */
258int sysfs_update_group(struct kobject *kobj,
259 const struct attribute_group *grp)
260{
261 return internal_create_group(kobj, 1, grp);
262}
263EXPORT_SYMBOL_GPL(sysfs_update_group);
264
265/**
266 * sysfs_remove_group: remove a group from a kobject
267 * @kobj: kobject to remove the group from
268 * @grp: group to remove
269 *
270 * This function removes a group of attributes from a kobject. The attributes
271 * previously have to have been created for this group, otherwise it will fail.
272 */
273void sysfs_remove_group(struct kobject *kobj,
274 const struct attribute_group *grp)
275{
276 struct kernfs_node *parent = kobj->sd;
277 struct kernfs_node *kn;
278
279 if (grp->name) {
280 kn = kernfs_find_and_get(parent, grp->name);
281 if (!kn) {
282 WARN(!kn, KERN_WARNING
283 "sysfs group '%s' not found for kobject '%s'\n",
284 grp->name, kobject_name(kobj));
285 return;
286 }
287 } else {
288 kn = parent;
289 kernfs_get(kn);
290 }
291
292 remove_files(kn, grp);
293 if (grp->name)
294 kernfs_remove(kn);
295
296 kernfs_put(kn);
297}
298EXPORT_SYMBOL_GPL(sysfs_remove_group);
299
300/**
301 * sysfs_remove_groups - remove a list of groups
302 *
303 * @kobj: The kobject for the groups to be removed from
304 * @groups: NULL terminated list of groups to be removed
305 *
306 * If groups is not NULL, remove the specified groups from the kobject.
307 */
308void sysfs_remove_groups(struct kobject *kobj,
309 const struct attribute_group **groups)
310{
311 int i;
312
313 if (!groups)
314 return;
315 for (i = 0; groups[i]; i++)
316 sysfs_remove_group(kobj, groups[i]);
317}
318EXPORT_SYMBOL_GPL(sysfs_remove_groups);
319
320/**
321 * sysfs_merge_group - merge files into a pre-existing attribute group.
322 * @kobj: The kobject containing the group.
323 * @grp: The files to create and the attribute group they belong to.
324 *
325 * This function returns an error if the group doesn't exist or any of the
326 * files already exist in that group, in which case none of the new files
327 * are created.
328 */
329int sysfs_merge_group(struct kobject *kobj,
330 const struct attribute_group *grp)
331{
332 struct kernfs_node *parent;
333 kuid_t uid;
334 kgid_t gid;
335 int error = 0;
336 struct attribute *const *attr;
337 int i;
338
339 parent = kernfs_find_and_get(kobj->sd, grp->name);
340 if (!parent)
341 return -ENOENT;
342
343 kobject_get_ownership(kobj, &uid, &gid);
344
345 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
346 error = sysfs_add_file_mode_ns(parent, *attr, (*attr)->mode,
347 uid, gid, NULL);
348 if (error) {
349 while (--i >= 0)
350 kernfs_remove_by_name(parent, (*--attr)->name);
351 }
352 kernfs_put(parent);
353
354 return error;
355}
356EXPORT_SYMBOL_GPL(sysfs_merge_group);
357
358/**
359 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
360 * @kobj: The kobject containing the group.
361 * @grp: The files to remove and the attribute group they belong to.
362 */
363void sysfs_unmerge_group(struct kobject *kobj,
364 const struct attribute_group *grp)
365{
366 struct kernfs_node *parent;
367 struct attribute *const *attr;
368
369 parent = kernfs_find_and_get(kobj->sd, grp->name);
370 if (parent) {
371 for (attr = grp->attrs; *attr; ++attr)
372 kernfs_remove_by_name(parent, (*attr)->name);
373 kernfs_put(parent);
374 }
375}
376EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
377
378/**
379 * sysfs_add_link_to_group - add a symlink to an attribute group.
380 * @kobj: The kobject containing the group.
381 * @group_name: The name of the group.
382 * @target: The target kobject of the symlink to create.
383 * @link_name: The name of the symlink to create.
384 */
385int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
386 struct kobject *target, const char *link_name)
387{
388 struct kernfs_node *parent;
389 int error = 0;
390
391 parent = kernfs_find_and_get(kobj->sd, group_name);
392 if (!parent)
393 return -ENOENT;
394
395 error = sysfs_create_link_sd(parent, target, link_name);
396 kernfs_put(parent);
397
398 return error;
399}
400EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
401
402/**
403 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
404 * @kobj: The kobject containing the group.
405 * @group_name: The name of the group.
406 * @link_name: The name of the symlink to remove.
407 */
408void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
409 const char *link_name)
410{
411 struct kernfs_node *parent;
412
413 parent = kernfs_find_and_get(kobj->sd, group_name);
414 if (parent) {
415 kernfs_remove_by_name(parent, link_name);
416 kernfs_put(parent);
417 }
418}
419EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
420
421/**
422 * compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
423 * to a group or an attribute
424 * @kobj: The kobject containing the group.
425 * @target_kobj: The target kobject.
426 * @target_name: The name of the target group or attribute.
427 * @symlink_name: The name of the symlink file (target_name will be
428 * considered if symlink_name is NULL).
429 */
430int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
431 struct kobject *target_kobj,
432 const char *target_name,
433 const char *symlink_name)
434{
435 struct kernfs_node *target;
436 struct kernfs_node *entry;
437 struct kernfs_node *link;
438
439 /*
440 * We don't own @target_kobj and it may be removed at any time.
441 * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
442 * for details.
443 */
444 spin_lock(&sysfs_symlink_target_lock);
445 target = target_kobj->sd;
446 if (target)
447 kernfs_get(target);
448 spin_unlock(&sysfs_symlink_target_lock);
449 if (!target)
450 return -ENOENT;
451
452 entry = kernfs_find_and_get(target, target_name);
453 if (!entry) {
454 kernfs_put(target);
455 return -ENOENT;
456 }
457
458 if (!symlink_name)
459 symlink_name = target_name;
460
461 link = kernfs_create_link(kobj->sd, symlink_name, entry);
462 if (PTR_ERR(link) == -EEXIST)
463 sysfs_warn_dup(kobj->sd, symlink_name);
464
465 kernfs_put(entry);
466 kernfs_put(target);
467 return PTR_ERR_OR_ZERO(link);
468}
469EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj);
470
471static int sysfs_group_attrs_change_owner(struct kernfs_node *grp_kn,
472 const struct attribute_group *grp,
473 struct iattr *newattrs)
474{
475 struct kernfs_node *kn;
476 int error;
477
478 if (grp->attrs) {
479 struct attribute *const *attr;
480
481 for (attr = grp->attrs; *attr; attr++) {
482 kn = kernfs_find_and_get(grp_kn, (*attr)->name);
483 if (!kn)
484 return -ENOENT;
485
486 error = kernfs_setattr(kn, newattrs);
487 kernfs_put(kn);
488 if (error)
489 return error;
490 }
491 }
492
493 if (grp->bin_attrs) {
494 struct bin_attribute *const *bin_attr;
495
496 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
497 kn = kernfs_find_and_get(grp_kn, (*bin_attr)->attr.name);
498 if (!kn)
499 return -ENOENT;
500
501 error = kernfs_setattr(kn, newattrs);
502 kernfs_put(kn);
503 if (error)
504 return error;
505 }
506 }
507
508 return 0;
509}
510
511/**
512 * sysfs_group_change_owner - change owner of an attribute group.
513 * @kobj: The kobject containing the group.
514 * @grp: The attribute group.
515 * @kuid: new owner's kuid
516 * @kgid: new owner's kgid
517 *
518 * Returns 0 on success or error code on failure.
519 */
520int sysfs_group_change_owner(struct kobject *kobj,
521 const struct attribute_group *grp, kuid_t kuid,
522 kgid_t kgid)
523{
524 struct kernfs_node *grp_kn;
525 int error;
526 struct iattr newattrs = {
527 .ia_valid = ATTR_UID | ATTR_GID,
528 .ia_uid = kuid,
529 .ia_gid = kgid,
530 };
531
532 if (!kobj->state_in_sysfs)
533 return -EINVAL;
534
535 if (grp->name) {
536 grp_kn = kernfs_find_and_get(kobj->sd, grp->name);
537 } else {
538 kernfs_get(kobj->sd);
539 grp_kn = kobj->sd;
540 }
541 if (!grp_kn)
542 return -ENOENT;
543
544 error = kernfs_setattr(grp_kn, &newattrs);
545 if (!error)
546 error = sysfs_group_attrs_change_owner(grp_kn, grp, &newattrs);
547
548 kernfs_put(grp_kn);
549
550 return error;
551}
552EXPORT_SYMBOL_GPL(sysfs_group_change_owner);
553
554/**
555 * sysfs_groups_change_owner - change owner of a set of attribute groups.
556 * @kobj: The kobject containing the groups.
557 * @groups: The attribute groups.
558 * @kuid: new owner's kuid
559 * @kgid: new owner's kgid
560 *
561 * Returns 0 on success or error code on failure.
562 */
563int sysfs_groups_change_owner(struct kobject *kobj,
564 const struct attribute_group **groups,
565 kuid_t kuid, kgid_t kgid)
566{
567 int error = 0, i;
568
569 if (!kobj->state_in_sysfs)
570 return -EINVAL;
571
572 if (!groups)
573 return 0;
574
575 for (i = 0; groups[i]; i++) {
576 error = sysfs_group_change_owner(kobj, groups[i], kuid, kgid);
577 if (error)
578 break;
579 }
580
581 return error;
582}
583EXPORT_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);