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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,
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 kernfs_remove_by_name(parent, (*bin_attr)->attr.name);
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 = (*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, 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, 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 int error;
112
113 BUG_ON(!kobj || (!update && !kobj->sd));
114
115 /* Updates may happen before the object has been instantiated */
116 if (unlikely(update && !kobj->sd))
117 return -EINVAL;
118 if (!grp->attrs && !grp->bin_attrs) {
119 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
120 kobj->name, grp->name ?: "");
121 return -EINVAL;
122 }
123 if (grp->name) {
124 kn = kernfs_create_dir(kobj->sd, grp->name,
125 S_IRWXU | S_IRUGO | S_IXUGO, kobj);
126 if (IS_ERR(kn)) {
127 if (PTR_ERR(kn) == -EEXIST)
128 sysfs_warn_dup(kobj->sd, grp->name);
129 return PTR_ERR(kn);
130 }
131 } else
132 kn = kobj->sd;
133 kernfs_get(kn);
134 error = create_files(kn, kobj, grp, update);
135 if (error) {
136 if (grp->name)
137 kernfs_remove(kn);
138 }
139 kernfs_put(kn);
140 return error;
141}
142
143/**
144 * sysfs_create_group - given a directory kobject, create an attribute group
145 * @kobj: The kobject to create the group on
146 * @grp: The attribute group to create
147 *
148 * This function creates a group for the first time. It will explicitly
149 * warn and error if any of the attribute files being created already exist.
150 *
151 * Returns 0 on success or error code on failure.
152 */
153int sysfs_create_group(struct kobject *kobj,
154 const struct attribute_group *grp)
155{
156 return internal_create_group(kobj, 0, grp);
157}
158EXPORT_SYMBOL_GPL(sysfs_create_group);
159
160/**
161 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
162 * @kobj: The kobject to create the group on
163 * @groups: The attribute groups to create, NULL terminated
164 *
165 * This function creates a bunch of attribute groups. If an error occurs when
166 * creating a group, all previously created groups will be removed, unwinding
167 * everything back to the original state when this function was called.
168 * It will explicitly warn and error if any of the attribute files being
169 * created already exist.
170 *
171 * Returns 0 on success or error code from sysfs_create_group on failure.
172 */
173int sysfs_create_groups(struct kobject *kobj,
174 const struct attribute_group **groups)
175{
176 int error = 0;
177 int i;
178
179 if (!groups)
180 return 0;
181
182 for (i = 0; groups[i]; i++) {
183 error = sysfs_create_group(kobj, groups[i]);
184 if (error) {
185 while (--i >= 0)
186 sysfs_remove_group(kobj, groups[i]);
187 break;
188 }
189 }
190 return error;
191}
192EXPORT_SYMBOL_GPL(sysfs_create_groups);
193
194/**
195 * sysfs_update_group - given a directory kobject, update an attribute group
196 * @kobj: The kobject to update the group on
197 * @grp: The attribute group to update
198 *
199 * This function updates an attribute group. Unlike
200 * sysfs_create_group(), it will explicitly not warn or error if any
201 * of the attribute files being created already exist. Furthermore,
202 * if the visibility of the files has changed through the is_visible()
203 * callback, it will update the permissions and add or remove the
204 * relevant files.
205 *
206 * The primary use for this function is to call it after making a change
207 * that affects group visibility.
208 *
209 * Returns 0 on success or error code on failure.
210 */
211int sysfs_update_group(struct kobject *kobj,
212 const struct attribute_group *grp)
213{
214 return internal_create_group(kobj, 1, grp);
215}
216EXPORT_SYMBOL_GPL(sysfs_update_group);
217
218/**
219 * sysfs_remove_group: remove a group from a kobject
220 * @kobj: kobject to remove the group from
221 * @grp: group to remove
222 *
223 * This function removes a group of attributes from a kobject. The attributes
224 * previously have to have been created for this group, otherwise it will fail.
225 */
226void sysfs_remove_group(struct kobject *kobj,
227 const struct attribute_group *grp)
228{
229 struct kernfs_node *parent = kobj->sd;
230 struct kernfs_node *kn;
231
232 if (grp->name) {
233 kn = kernfs_find_and_get(parent, grp->name);
234 if (!kn) {
235 WARN(!kn, KERN_WARNING
236 "sysfs group %p not found for kobject '%s'\n",
237 grp, kobject_name(kobj));
238 return;
239 }
240 } else {
241 kn = parent;
242 kernfs_get(kn);
243 }
244
245 remove_files(kn, grp);
246 if (grp->name)
247 kernfs_remove(kn);
248
249 kernfs_put(kn);
250}
251EXPORT_SYMBOL_GPL(sysfs_remove_group);
252
253/**
254 * sysfs_remove_groups - remove a list of groups
255 *
256 * @kobj: The kobject for the groups to be removed from
257 * @groups: NULL terminated list of groups to be removed
258 *
259 * If groups is not NULL, remove the specified groups from the kobject.
260 */
261void sysfs_remove_groups(struct kobject *kobj,
262 const struct attribute_group **groups)
263{
264 int i;
265
266 if (!groups)
267 return;
268 for (i = 0; groups[i]; i++)
269 sysfs_remove_group(kobj, groups[i]);
270}
271EXPORT_SYMBOL_GPL(sysfs_remove_groups);
272
273/**
274 * sysfs_merge_group - merge files into a pre-existing attribute group.
275 * @kobj: The kobject containing the group.
276 * @grp: The files to create and the attribute group they belong to.
277 *
278 * This function returns an error if the group doesn't exist or any of the
279 * files already exist in that group, in which case none of the new files
280 * are created.
281 */
282int sysfs_merge_group(struct kobject *kobj,
283 const struct attribute_group *grp)
284{
285 struct kernfs_node *parent;
286 int error = 0;
287 struct attribute *const *attr;
288 int i;
289
290 parent = kernfs_find_and_get(kobj->sd, grp->name);
291 if (!parent)
292 return -ENOENT;
293
294 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
295 error = sysfs_add_file(parent, *attr, false);
296 if (error) {
297 while (--i >= 0)
298 kernfs_remove_by_name(parent, (*--attr)->name);
299 }
300 kernfs_put(parent);
301
302 return error;
303}
304EXPORT_SYMBOL_GPL(sysfs_merge_group);
305
306/**
307 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
308 * @kobj: The kobject containing the group.
309 * @grp: The files to remove and the attribute group they belong to.
310 */
311void sysfs_unmerge_group(struct kobject *kobj,
312 const struct attribute_group *grp)
313{
314 struct kernfs_node *parent;
315 struct attribute *const *attr;
316
317 parent = kernfs_find_and_get(kobj->sd, grp->name);
318 if (parent) {
319 for (attr = grp->attrs; *attr; ++attr)
320 kernfs_remove_by_name(parent, (*attr)->name);
321 kernfs_put(parent);
322 }
323}
324EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
325
326/**
327 * sysfs_add_link_to_group - add a symlink to an attribute group.
328 * @kobj: The kobject containing the group.
329 * @group_name: The name of the group.
330 * @target: The target kobject of the symlink to create.
331 * @link_name: The name of the symlink to create.
332 */
333int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
334 struct kobject *target, const char *link_name)
335{
336 struct kernfs_node *parent;
337 int error = 0;
338
339 parent = kernfs_find_and_get(kobj->sd, group_name);
340 if (!parent)
341 return -ENOENT;
342
343 error = sysfs_create_link_sd(parent, target, link_name);
344 kernfs_put(parent);
345
346 return error;
347}
348EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
349
350/**
351 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
352 * @kobj: The kobject containing the group.
353 * @group_name: The name of the group.
354 * @link_name: The name of the symlink to remove.
355 */
356void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
357 const char *link_name)
358{
359 struct kernfs_node *parent;
360
361 parent = kernfs_find_and_get(kobj->sd, group_name);
362 if (parent) {
363 kernfs_remove_by_name(parent, link_name);
364 kernfs_put(parent);
365 }
366}
367EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
368
369/**
370 * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
371 * to a group or an attribute
372 * @kobj: The kobject containing the group.
373 * @target_kobj: The target kobject.
374 * @target_name: The name of the target group or attribute.
375 */
376int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
377 struct kobject *target_kobj,
378 const char *target_name)
379{
380 struct kernfs_node *target;
381 struct kernfs_node *entry;
382 struct kernfs_node *link;
383
384 /*
385 * We don't own @target_kobj and it may be removed at any time.
386 * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
387 * for details.
388 */
389 spin_lock(&sysfs_symlink_target_lock);
390 target = target_kobj->sd;
391 if (target)
392 kernfs_get(target);
393 spin_unlock(&sysfs_symlink_target_lock);
394 if (!target)
395 return -ENOENT;
396
397 entry = kernfs_find_and_get(target_kobj->sd, target_name);
398 if (!entry) {
399 kernfs_put(target);
400 return -ENOENT;
401 }
402
403 link = kernfs_create_link(kobj->sd, target_name, entry);
404 if (IS_ERR(link) && PTR_ERR(link) == -EEXIST)
405 sysfs_warn_dup(kobj->sd, target_name);
406
407 kernfs_put(entry);
408 kernfs_put(target);
409 return IS_ERR(link) ? PTR_ERR(link) : 0;
410}
411EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);