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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 umode_t __first_visible(const struct attribute_group *grp, struct kobject *kobj)
35{
36 if (grp->attrs && grp->attrs[0] && grp->is_visible)
37 return grp->is_visible(kobj, grp->attrs[0], 0);
38
39 if (grp->bin_attrs && grp->bin_attrs[0] && grp->is_bin_visible)
40 return grp->is_bin_visible(kobj, grp->bin_attrs[0], 0);
41
42 return 0;
43}
44
45static int create_files(struct kernfs_node *parent, struct kobject *kobj,
46 kuid_t uid, kgid_t gid,
47 const struct attribute_group *grp, int update)
48{
49 struct attribute *const *attr;
50 struct bin_attribute *const *bin_attr;
51 int error = 0, i;
52
53 if (grp->attrs) {
54 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
55 umode_t mode = (*attr)->mode;
56
57 /*
58 * In update mode, we're changing the permissions or
59 * visibility. Do this by first removing then
60 * re-adding (if required) the file.
61 */
62 if (update)
63 kernfs_remove_by_name(parent, (*attr)->name);
64 if (grp->is_visible) {
65 mode = grp->is_visible(kobj, *attr, i);
66 mode &= ~SYSFS_GROUP_INVISIBLE;
67 if (!mode)
68 continue;
69 }
70
71 WARN(mode & ~(SYSFS_PREALLOC | 0664),
72 "Attribute %s: Invalid permissions 0%o\n",
73 (*attr)->name, mode);
74
75 mode &= SYSFS_PREALLOC | 0664;
76 error = sysfs_add_file_mode_ns(parent, *attr, mode, uid,
77 gid, NULL);
78 if (unlikely(error))
79 break;
80 }
81 if (error) {
82 remove_files(parent, grp);
83 goto exit;
84 }
85 }
86
87 if (grp->bin_attrs) {
88 for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) {
89 umode_t mode = (*bin_attr)->attr.mode;
90 size_t size = (*bin_attr)->size;
91
92 if (update)
93 kernfs_remove_by_name(parent,
94 (*bin_attr)->attr.name);
95 if (grp->is_bin_visible) {
96 mode = grp->is_bin_visible(kobj, *bin_attr, i);
97 mode &= ~SYSFS_GROUP_INVISIBLE;
98 if (!mode)
99 continue;
100 }
101 if (grp->bin_size)
102 size = grp->bin_size(kobj, *bin_attr, i);
103
104 WARN(mode & ~(SYSFS_PREALLOC | 0664),
105 "Attribute %s: Invalid permissions 0%o\n",
106 (*bin_attr)->attr.name, mode);
107
108 mode &= SYSFS_PREALLOC | 0664;
109 error = sysfs_add_bin_file_mode_ns(parent, *bin_attr,
110 mode, size, uid, gid,
111 NULL);
112 if (error)
113 break;
114 }
115 if (error)
116 remove_files(parent, grp);
117 }
118exit:
119 return error;
120}
121
122
123static int internal_create_group(struct kobject *kobj, int update,
124 const struct attribute_group *grp)
125{
126 struct kernfs_node *kn;
127 kuid_t uid;
128 kgid_t gid;
129 int error;
130
131 if (WARN_ON(!kobj || (!update && !kobj->sd)))
132 return -EINVAL;
133
134 /* Updates may happen before the object has been instantiated */
135 if (unlikely(update && !kobj->sd))
136 return -EINVAL;
137
138 if (!grp->attrs && !grp->bin_attrs) {
139 pr_debug("sysfs: (bin_)attrs not set by subsystem for group: %s/%s, skipping\n",
140 kobj->name, grp->name ?: "");
141 return 0;
142 }
143
144 kobject_get_ownership(kobj, &uid, &gid);
145 if (grp->name) {
146 umode_t mode = __first_visible(grp, kobj);
147
148 if (mode & SYSFS_GROUP_INVISIBLE)
149 mode = 0;
150 else
151 mode = S_IRWXU | S_IRUGO | S_IXUGO;
152
153 if (update) {
154 kn = kernfs_find_and_get(kobj->sd, grp->name);
155 if (!kn) {
156 pr_debug("attr grp %s/%s not created yet\n",
157 kobj->name, grp->name);
158 /* may have been invisible prior to this update */
159 update = 0;
160 } else if (!mode) {
161 sysfs_remove_group(kobj, grp);
162 kernfs_put(kn);
163 return 0;
164 }
165 }
166
167 if (!update) {
168 if (!mode)
169 return 0;
170 kn = kernfs_create_dir_ns(kobj->sd, grp->name, mode,
171 uid, gid, kobj, NULL);
172 if (IS_ERR(kn)) {
173 if (PTR_ERR(kn) == -EEXIST)
174 sysfs_warn_dup(kobj->sd, grp->name);
175 return PTR_ERR(kn);
176 }
177 }
178 } else {
179 kn = kobj->sd;
180 }
181
182 kernfs_get(kn);
183 error = create_files(kn, kobj, uid, gid, grp, update);
184 if (error) {
185 if (grp->name)
186 kernfs_remove(kn);
187 }
188 kernfs_put(kn);
189
190 if (grp->name && update)
191 kernfs_put(kn);
192
193 return error;
194}
195
196/**
197 * sysfs_create_group - given a directory kobject, create an attribute group
198 * @kobj: The kobject to create the group on
199 * @grp: The attribute group to create
200 *
201 * This function creates a group for the first time. It will explicitly
202 * warn and error if any of the attribute files being created already exist.
203 *
204 * Returns 0 on success or error code on failure.
205 */
206int sysfs_create_group(struct kobject *kobj,
207 const struct attribute_group *grp)
208{
209 return internal_create_group(kobj, 0, grp);
210}
211EXPORT_SYMBOL_GPL(sysfs_create_group);
212
213static int internal_create_groups(struct kobject *kobj, int update,
214 const struct attribute_group **groups)
215{
216 int error = 0;
217 int i;
218
219 if (!groups)
220 return 0;
221
222 for (i = 0; groups[i]; i++) {
223 error = internal_create_group(kobj, update, groups[i]);
224 if (error) {
225 while (--i >= 0)
226 sysfs_remove_group(kobj, groups[i]);
227 break;
228 }
229 }
230 return error;
231}
232
233/**
234 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
235 * @kobj: The kobject to create the group on
236 * @groups: The attribute groups to create, NULL terminated
237 *
238 * This function creates a bunch of attribute groups. If an error occurs when
239 * creating a group, all previously created groups will be removed, unwinding
240 * everything back to the original state when this function was called.
241 * It will explicitly warn and error if any of the attribute files being
242 * created already exist.
243 *
244 * Returns 0 on success or error code from sysfs_create_group on failure.
245 */
246int sysfs_create_groups(struct kobject *kobj,
247 const struct attribute_group **groups)
248{
249 return internal_create_groups(kobj, 0, groups);
250}
251EXPORT_SYMBOL_GPL(sysfs_create_groups);
252
253/**
254 * sysfs_update_groups - given a directory kobject, create a bunch of attribute groups
255 * @kobj: The kobject to update the group on
256 * @groups: The attribute groups to update, NULL terminated
257 *
258 * This function update a bunch of attribute groups. If an error occurs when
259 * updating a group, all previously updated groups will be removed together
260 * with already existing (not updated) attributes.
261 *
262 * Returns 0 on success or error code from sysfs_update_group on failure.
263 */
264int sysfs_update_groups(struct kobject *kobj,
265 const struct attribute_group **groups)
266{
267 return internal_create_groups(kobj, 1, groups);
268}
269EXPORT_SYMBOL_GPL(sysfs_update_groups);
270
271/**
272 * sysfs_update_group - given a directory kobject, update an attribute group
273 * @kobj: The kobject to update the group on
274 * @grp: The attribute group to update
275 *
276 * This function updates an attribute group. Unlike
277 * sysfs_create_group(), it will explicitly not warn or error if any
278 * of the attribute files being created already exist. Furthermore,
279 * if the visibility of the files has changed through the is_visible()
280 * callback, it will update the permissions and add or remove the
281 * relevant files. Changing a group's name (subdirectory name under
282 * kobj's directory in sysfs) is not allowed.
283 *
284 * The primary use for this function is to call it after making a change
285 * that affects group visibility.
286 *
287 * Returns 0 on success or error code on failure.
288 */
289int sysfs_update_group(struct kobject *kobj,
290 const struct attribute_group *grp)
291{
292 return internal_create_group(kobj, 1, grp);
293}
294EXPORT_SYMBOL_GPL(sysfs_update_group);
295
296/**
297 * sysfs_remove_group: remove a group from a kobject
298 * @kobj: kobject to remove the group from
299 * @grp: group to remove
300 *
301 * This function removes a group of attributes from a kobject. The attributes
302 * previously have to have been created for this group, otherwise it will fail.
303 */
304void sysfs_remove_group(struct kobject *kobj,
305 const struct attribute_group *grp)
306{
307 struct kernfs_node *parent = kobj->sd;
308 struct kernfs_node *kn;
309
310 if (grp->name) {
311 kn = kernfs_find_and_get(parent, grp->name);
312 if (!kn) {
313 pr_debug("sysfs group '%s' not found for kobject '%s'\n",
314 grp->name, kobject_name(kobj));
315 return;
316 }
317 } else {
318 kn = parent;
319 kernfs_get(kn);
320 }
321
322 remove_files(kn, grp);
323 if (grp->name)
324 kernfs_remove(kn);
325
326 kernfs_put(kn);
327}
328EXPORT_SYMBOL_GPL(sysfs_remove_group);
329
330/**
331 * sysfs_remove_groups - remove a list of groups
332 *
333 * @kobj: The kobject for the groups to be removed from
334 * @groups: NULL terminated list of groups to be removed
335 *
336 * If groups is not NULL, remove the specified groups from the kobject.
337 */
338void sysfs_remove_groups(struct kobject *kobj,
339 const struct attribute_group **groups)
340{
341 int i;
342
343 if (!groups)
344 return;
345 for (i = 0; groups[i]; i++)
346 sysfs_remove_group(kobj, groups[i]);
347}
348EXPORT_SYMBOL_GPL(sysfs_remove_groups);
349
350/**
351 * sysfs_merge_group - merge files into a pre-existing named attribute group.
352 * @kobj: The kobject containing the group.
353 * @grp: The files to create and the attribute group they belong to.
354 *
355 * This function returns an error if the group doesn't exist, the .name field is
356 * NULL or any of the files already exist in that group, in which case none of
357 * the new files are created.
358 */
359int sysfs_merge_group(struct kobject *kobj,
360 const struct attribute_group *grp)
361{
362 struct kernfs_node *parent;
363 kuid_t uid;
364 kgid_t gid;
365 int error = 0;
366 struct attribute *const *attr;
367 int i;
368
369 parent = kernfs_find_and_get(kobj->sd, grp->name);
370 if (!parent)
371 return -ENOENT;
372
373 kobject_get_ownership(kobj, &uid, &gid);
374
375 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
376 error = sysfs_add_file_mode_ns(parent, *attr, (*attr)->mode,
377 uid, gid, NULL);
378 if (error) {
379 while (--i >= 0)
380 kernfs_remove_by_name(parent, (*--attr)->name);
381 }
382 kernfs_put(parent);
383
384 return error;
385}
386EXPORT_SYMBOL_GPL(sysfs_merge_group);
387
388/**
389 * sysfs_unmerge_group - remove files from a pre-existing named attribute group.
390 * @kobj: The kobject containing the group.
391 * @grp: The files to remove and the attribute group they belong to.
392 */
393void sysfs_unmerge_group(struct kobject *kobj,
394 const struct attribute_group *grp)
395{
396 struct kernfs_node *parent;
397 struct attribute *const *attr;
398
399 parent = kernfs_find_and_get(kobj->sd, grp->name);
400 if (parent) {
401 for (attr = grp->attrs; *attr; ++attr)
402 kernfs_remove_by_name(parent, (*attr)->name);
403 kernfs_put(parent);
404 }
405}
406EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
407
408/**
409 * sysfs_add_link_to_group - add a symlink to an attribute group.
410 * @kobj: The kobject containing the group.
411 * @group_name: The name of the group.
412 * @target: The target kobject of the symlink to create.
413 * @link_name: The name of the symlink to create.
414 */
415int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
416 struct kobject *target, const char *link_name)
417{
418 struct kernfs_node *parent;
419 int error = 0;
420
421 parent = kernfs_find_and_get(kobj->sd, group_name);
422 if (!parent)
423 return -ENOENT;
424
425 error = sysfs_create_link_sd(parent, target, link_name);
426 kernfs_put(parent);
427
428 return error;
429}
430EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
431
432/**
433 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
434 * @kobj: The kobject containing the group.
435 * @group_name: The name of the group.
436 * @link_name: The name of the symlink to remove.
437 */
438void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
439 const char *link_name)
440{
441 struct kernfs_node *parent;
442
443 parent = kernfs_find_and_get(kobj->sd, group_name);
444 if (parent) {
445 kernfs_remove_by_name(parent, link_name);
446 kernfs_put(parent);
447 }
448}
449EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
450
451/**
452 * compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
453 * to a group or an attribute
454 * @kobj: The kobject containing the group.
455 * @target_kobj: The target kobject.
456 * @target_name: The name of the target group or attribute.
457 * @symlink_name: The name of the symlink file (target_name will be
458 * considered if symlink_name is NULL).
459 */
460int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
461 struct kobject *target_kobj,
462 const char *target_name,
463 const char *symlink_name)
464{
465 struct kernfs_node *target;
466 struct kernfs_node *entry;
467 struct kernfs_node *link;
468
469 /*
470 * We don't own @target_kobj and it may be removed at any time.
471 * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
472 * for details.
473 */
474 spin_lock(&sysfs_symlink_target_lock);
475 target = target_kobj->sd;
476 if (target)
477 kernfs_get(target);
478 spin_unlock(&sysfs_symlink_target_lock);
479 if (!target)
480 return -ENOENT;
481
482 entry = kernfs_find_and_get(target, target_name);
483 if (!entry) {
484 kernfs_put(target);
485 return -ENOENT;
486 }
487
488 if (!symlink_name)
489 symlink_name = target_name;
490
491 link = kernfs_create_link(kobj->sd, symlink_name, entry);
492 if (PTR_ERR(link) == -EEXIST)
493 sysfs_warn_dup(kobj->sd, symlink_name);
494
495 kernfs_put(entry);
496 kernfs_put(target);
497 return PTR_ERR_OR_ZERO(link);
498}
499EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj);
500
501static int sysfs_group_attrs_change_owner(struct kernfs_node *grp_kn,
502 const struct attribute_group *grp,
503 struct iattr *newattrs)
504{
505 struct kernfs_node *kn;
506 int error;
507
508 if (grp->attrs) {
509 struct attribute *const *attr;
510
511 for (attr = grp->attrs; *attr; attr++) {
512 kn = kernfs_find_and_get(grp_kn, (*attr)->name);
513 if (!kn)
514 return -ENOENT;
515
516 error = kernfs_setattr(kn, newattrs);
517 kernfs_put(kn);
518 if (error)
519 return error;
520 }
521 }
522
523 if (grp->bin_attrs) {
524 struct bin_attribute *const *bin_attr;
525
526 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
527 kn = kernfs_find_and_get(grp_kn, (*bin_attr)->attr.name);
528 if (!kn)
529 return -ENOENT;
530
531 error = kernfs_setattr(kn, newattrs);
532 kernfs_put(kn);
533 if (error)
534 return error;
535 }
536 }
537
538 return 0;
539}
540
541/**
542 * sysfs_group_change_owner - change owner of an attribute group.
543 * @kobj: The kobject containing the group.
544 * @grp: The attribute group.
545 * @kuid: new owner's kuid
546 * @kgid: new owner's kgid
547 *
548 * Returns 0 on success or error code on failure.
549 */
550int sysfs_group_change_owner(struct kobject *kobj,
551 const struct attribute_group *grp, kuid_t kuid,
552 kgid_t kgid)
553{
554 struct kernfs_node *grp_kn;
555 int error;
556 struct iattr newattrs = {
557 .ia_valid = ATTR_UID | ATTR_GID,
558 .ia_uid = kuid,
559 .ia_gid = kgid,
560 };
561
562 if (!kobj->state_in_sysfs)
563 return -EINVAL;
564
565 if (grp->name) {
566 grp_kn = kernfs_find_and_get(kobj->sd, grp->name);
567 } else {
568 kernfs_get(kobj->sd);
569 grp_kn = kobj->sd;
570 }
571 if (!grp_kn)
572 return -ENOENT;
573
574 error = kernfs_setattr(grp_kn, &newattrs);
575 if (!error)
576 error = sysfs_group_attrs_change_owner(grp_kn, grp, &newattrs);
577
578 kernfs_put(grp_kn);
579
580 return error;
581}
582EXPORT_SYMBOL_GPL(sysfs_group_change_owner);
583
584/**
585 * sysfs_groups_change_owner - change owner of a set of attribute groups.
586 * @kobj: The kobject containing the groups.
587 * @groups: The attribute groups.
588 * @kuid: new owner's kuid
589 * @kgid: new owner's kgid
590 *
591 * Returns 0 on success or error code on failure.
592 */
593int sysfs_groups_change_owner(struct kobject *kobj,
594 const struct attribute_group **groups,
595 kuid_t kuid, kgid_t kgid)
596{
597 int error = 0, i;
598
599 if (!kobj->state_in_sysfs)
600 return -EINVAL;
601
602 if (!groups)
603 return 0;
604
605 for (i = 0; groups[i]; i++) {
606 error = sysfs_group_change_owner(kobj, groups[i], kuid, kgid);
607 if (error)
608 break;
609 }
610
611 return error;
612}
613EXPORT_SYMBOL_GPL(sysfs_groups_change_owner);