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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 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);
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 "sysfs.h"
17
18
19static void remove_files(struct kernfs_node *parent,
20 const struct attribute_group *grp)
21{
22 struct attribute *const *attr;
23 struct bin_attribute *const *bin_attr;
24
25 if (grp->attrs)
26 for (attr = grp->attrs; *attr; attr++)
27 kernfs_remove_by_name(parent, (*attr)->name);
28 if (grp->bin_attrs)
29 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
30 kernfs_remove_by_name(parent, (*bin_attr)->attr.name);
31}
32
33static int create_files(struct kernfs_node *parent, struct kobject *kobj,
34 const struct attribute_group *grp, int update)
35{
36 struct attribute *const *attr;
37 struct bin_attribute *const *bin_attr;
38 int error = 0, i;
39
40 if (grp->attrs) {
41 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
42 umode_t mode = (*attr)->mode;
43
44 /*
45 * In update mode, we're changing the permissions or
46 * visibility. Do this by first removing then
47 * re-adding (if required) the file.
48 */
49 if (update)
50 kernfs_remove_by_name(parent, (*attr)->name);
51 if (grp->is_visible) {
52 mode = grp->is_visible(kobj, *attr, i);
53 if (!mode)
54 continue;
55 }
56
57 WARN(mode & ~(SYSFS_PREALLOC | 0664),
58 "Attribute %s: Invalid permissions 0%o\n",
59 (*attr)->name, mode);
60
61 mode &= SYSFS_PREALLOC | 0664;
62 error = sysfs_add_file_mode_ns(parent, *attr, false,
63 mode, NULL);
64 if (unlikely(error))
65 break;
66 }
67 if (error) {
68 remove_files(parent, grp);
69 goto exit;
70 }
71 }
72
73 if (grp->bin_attrs) {
74 for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) {
75 umode_t mode = (*bin_attr)->attr.mode;
76
77 if (update)
78 kernfs_remove_by_name(parent,
79 (*bin_attr)->attr.name);
80 if (grp->is_bin_visible) {
81 mode = grp->is_bin_visible(kobj, *bin_attr, i);
82 if (!mode)
83 continue;
84 }
85
86 WARN(mode & ~(SYSFS_PREALLOC | 0664),
87 "Attribute %s: Invalid permissions 0%o\n",
88 (*bin_attr)->attr.name, mode);
89
90 mode &= SYSFS_PREALLOC | 0664;
91 error = sysfs_add_file_mode_ns(parent,
92 &(*bin_attr)->attr, true,
93 mode, NULL);
94 if (error)
95 break;
96 }
97 if (error)
98 remove_files(parent, grp);
99 }
100exit:
101 return error;
102}
103
104
105static int internal_create_group(struct kobject *kobj, int update,
106 const struct attribute_group *grp)
107{
108 struct kernfs_node *kn;
109 int error;
110
111 BUG_ON(!kobj || (!update && !kobj->sd));
112
113 /* Updates may happen before the object has been instantiated */
114 if (unlikely(update && !kobj->sd))
115 return -EINVAL;
116 if (!grp->attrs && !grp->bin_attrs) {
117 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
118 kobj->name, grp->name ?: "");
119 return -EINVAL;
120 }
121 if (grp->name) {
122 kn = kernfs_create_dir(kobj->sd, grp->name,
123 S_IRWXU | S_IRUGO | S_IXUGO, kobj);
124 if (IS_ERR(kn)) {
125 if (PTR_ERR(kn) == -EEXIST)
126 sysfs_warn_dup(kobj->sd, grp->name);
127 return PTR_ERR(kn);
128 }
129 } else
130 kn = kobj->sd;
131 kernfs_get(kn);
132 error = create_files(kn, kobj, grp, update);
133 if (error) {
134 if (grp->name)
135 kernfs_remove(kn);
136 }
137 kernfs_put(kn);
138 return error;
139}
140
141/**
142 * sysfs_create_group - given a directory kobject, create an attribute group
143 * @kobj: The kobject to create the group on
144 * @grp: The attribute group to create
145 *
146 * This function creates a group for the first time. It will explicitly
147 * warn and error if any of the attribute files being created already exist.
148 *
149 * Returns 0 on success or error code on failure.
150 */
151int sysfs_create_group(struct kobject *kobj,
152 const struct attribute_group *grp)
153{
154 return internal_create_group(kobj, 0, grp);
155}
156EXPORT_SYMBOL_GPL(sysfs_create_group);
157
158/**
159 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
160 * @kobj: The kobject to create the group on
161 * @groups: The attribute groups to create, NULL terminated
162 *
163 * This function creates a bunch of attribute groups. If an error occurs when
164 * creating a group, all previously created groups will be removed, unwinding
165 * everything back to the original state when this function was called.
166 * It will explicitly warn and error if any of the attribute files being
167 * created already exist.
168 *
169 * Returns 0 on success or error code from sysfs_create_group on failure.
170 */
171int sysfs_create_groups(struct kobject *kobj,
172 const struct attribute_group **groups)
173{
174 int error = 0;
175 int i;
176
177 if (!groups)
178 return 0;
179
180 for (i = 0; groups[i]; i++) {
181 error = sysfs_create_group(kobj, groups[i]);
182 if (error) {
183 while (--i >= 0)
184 sysfs_remove_group(kobj, groups[i]);
185 break;
186 }
187 }
188 return error;
189}
190EXPORT_SYMBOL_GPL(sysfs_create_groups);
191
192/**
193 * sysfs_update_group - given a directory kobject, update an attribute group
194 * @kobj: The kobject to update the group on
195 * @grp: The attribute group to update
196 *
197 * This function updates an attribute group. Unlike
198 * sysfs_create_group(), it will explicitly not warn or error if any
199 * of the attribute files being created already exist. Furthermore,
200 * if the visibility of the files has changed through the is_visible()
201 * callback, it will update the permissions and add or remove the
202 * relevant files.
203 *
204 * The primary use for this function is to call it after making a change
205 * that affects group visibility.
206 *
207 * Returns 0 on success or error code on failure.
208 */
209int sysfs_update_group(struct kobject *kobj,
210 const struct attribute_group *grp)
211{
212 return internal_create_group(kobj, 1, grp);
213}
214EXPORT_SYMBOL_GPL(sysfs_update_group);
215
216/**
217 * sysfs_remove_group: remove a group from a kobject
218 * @kobj: kobject to remove the group from
219 * @grp: group to remove
220 *
221 * This function removes a group of attributes from a kobject. The attributes
222 * previously have to have been created for this group, otherwise it will fail.
223 */
224void sysfs_remove_group(struct kobject *kobj,
225 const struct attribute_group *grp)
226{
227 struct kernfs_node *parent = kobj->sd;
228 struct kernfs_node *kn;
229
230 if (grp->name) {
231 kn = kernfs_find_and_get(parent, grp->name);
232 if (!kn) {
233 WARN(!kn, KERN_WARNING
234 "sysfs group '%s' not found for kobject '%s'\n",
235 grp->name, kobject_name(kobj));
236 return;
237 }
238 } else {
239 kn = parent;
240 kernfs_get(kn);
241 }
242
243 remove_files(kn, grp);
244 if (grp->name)
245 kernfs_remove(kn);
246
247 kernfs_put(kn);
248}
249EXPORT_SYMBOL_GPL(sysfs_remove_group);
250
251/**
252 * sysfs_remove_groups - remove a list of groups
253 *
254 * @kobj: The kobject for the groups to be removed from
255 * @groups: NULL terminated list of groups to be removed
256 *
257 * If groups is not NULL, remove the specified groups from the kobject.
258 */
259void sysfs_remove_groups(struct kobject *kobj,
260 const struct attribute_group **groups)
261{
262 int i;
263
264 if (!groups)
265 return;
266 for (i = 0; groups[i]; i++)
267 sysfs_remove_group(kobj, groups[i]);
268}
269EXPORT_SYMBOL_GPL(sysfs_remove_groups);
270
271/**
272 * sysfs_merge_group - merge files into a pre-existing attribute group.
273 * @kobj: The kobject containing the group.
274 * @grp: The files to create and the attribute group they belong to.
275 *
276 * This function returns an error if the group doesn't exist or any of the
277 * files already exist in that group, in which case none of the new files
278 * are created.
279 */
280int sysfs_merge_group(struct kobject *kobj,
281 const struct attribute_group *grp)
282{
283 struct kernfs_node *parent;
284 int error = 0;
285 struct attribute *const *attr;
286 int i;
287
288 parent = kernfs_find_and_get(kobj->sd, grp->name);
289 if (!parent)
290 return -ENOENT;
291
292 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
293 error = sysfs_add_file(parent, *attr, false);
294 if (error) {
295 while (--i >= 0)
296 kernfs_remove_by_name(parent, (*--attr)->name);
297 }
298 kernfs_put(parent);
299
300 return error;
301}
302EXPORT_SYMBOL_GPL(sysfs_merge_group);
303
304/**
305 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
306 * @kobj: The kobject containing the group.
307 * @grp: The files to remove and the attribute group they belong to.
308 */
309void sysfs_unmerge_group(struct kobject *kobj,
310 const struct attribute_group *grp)
311{
312 struct kernfs_node *parent;
313 struct attribute *const *attr;
314
315 parent = kernfs_find_and_get(kobj->sd, grp->name);
316 if (parent) {
317 for (attr = grp->attrs; *attr; ++attr)
318 kernfs_remove_by_name(parent, (*attr)->name);
319 kernfs_put(parent);
320 }
321}
322EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
323
324/**
325 * sysfs_add_link_to_group - add a symlink to an attribute group.
326 * @kobj: The kobject containing the group.
327 * @group_name: The name of the group.
328 * @target: The target kobject of the symlink to create.
329 * @link_name: The name of the symlink to create.
330 */
331int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
332 struct kobject *target, const char *link_name)
333{
334 struct kernfs_node *parent;
335 int error = 0;
336
337 parent = kernfs_find_and_get(kobj->sd, group_name);
338 if (!parent)
339 return -ENOENT;
340
341 error = sysfs_create_link_sd(parent, target, link_name);
342 kernfs_put(parent);
343
344 return error;
345}
346EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
347
348/**
349 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
350 * @kobj: The kobject containing the group.
351 * @group_name: The name of the group.
352 * @link_name: The name of the symlink to remove.
353 */
354void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
355 const char *link_name)
356{
357 struct kernfs_node *parent;
358
359 parent = kernfs_find_and_get(kobj->sd, group_name);
360 if (parent) {
361 kernfs_remove_by_name(parent, link_name);
362 kernfs_put(parent);
363 }
364}
365EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
366
367/**
368 * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
369 * to a group or an attribute
370 * @kobj: The kobject containing the group.
371 * @target_kobj: The target kobject.
372 * @target_name: The name of the target group or attribute.
373 */
374int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
375 struct kobject *target_kobj,
376 const char *target_name)
377{
378 struct kernfs_node *target;
379 struct kernfs_node *entry;
380 struct kernfs_node *link;
381
382 /*
383 * We don't own @target_kobj and it may be removed at any time.
384 * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
385 * for details.
386 */
387 spin_lock(&sysfs_symlink_target_lock);
388 target = target_kobj->sd;
389 if (target)
390 kernfs_get(target);
391 spin_unlock(&sysfs_symlink_target_lock);
392 if (!target)
393 return -ENOENT;
394
395 entry = kernfs_find_and_get(target_kobj->sd, target_name);
396 if (!entry) {
397 kernfs_put(target);
398 return -ENOENT;
399 }
400
401 link = kernfs_create_link(kobj->sd, target_name, entry);
402 if (IS_ERR(link) && PTR_ERR(link) == -EEXIST)
403 sysfs_warn_dup(kobj->sd, target_name);
404
405 kernfs_put(entry);
406 kernfs_put(target);
407 return PTR_ERR_OR_ZERO(link);
408}
409EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);