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