blob: dc1358b5ec95814c4e0f0ca0bec3d2b847029b24 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * fs/sysfs/group.c - Operations for adding/removing multiple files at once.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
Greg Kroah-Hartman9e2a47e2013-08-21 16:14:11 -07006 * Copyright (c) 2013 Greg Kroah-Hartman
7 * Copyright (c) 2013 The Linux Foundation
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 *
Greg Kroah-Hartmane6c56922013-08-21 16:06:14 -07009 * This file is released undert the GPL v2.
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
11 */
12
13#include <linux/kobject.h>
14#include <linux/module.h>
15#include <linux/dcache.h>
Christoph Hellwig5f45f1a2005-06-23 00:09:12 -070016#include <linux/namei.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/err.h>
18#include "sysfs.h"
19
20
Robert ABEL9f70a402014-05-05 15:17:20 +020021static void remove_files(struct kernfs_node *parent,
Tejun Heo608e2662007-06-14 04:27:22 +090022 const struct attribute_group *grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070023{
Greg Kroah-Hartman995d8ed2013-08-21 16:07:29 -070024 struct attribute *const *attr;
25 struct bin_attribute *const *bin_attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070027 if (grp->attrs)
28 for (attr = grp->attrs; *attr; attr++)
Tejun Heo324a56e2013-12-11 14:11:53 -050029 kernfs_remove_by_name(parent, (*attr)->name);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070030 if (grp->bin_attrs)
31 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
Robert ABEL9f70a402014-05-05 15:17:20 +020032 kernfs_remove_by_name(parent, (*bin_attr)->attr.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033}
34
Tejun Heo324a56e2013-12-11 14:11:53 -050035static int create_files(struct kernfs_node *parent, struct kobject *kobj,
James Bottomley0f423892008-03-20 20:47:52 -050036 const struct attribute_group *grp, int update)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037{
Greg Kroah-Hartman995d8ed2013-08-21 16:07:29 -070038 struct attribute *const *attr;
39 struct bin_attribute *const *bin_attr;
James Bottomleyd4acd722007-10-31 09:38:04 -050040 int error = 0, i;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070042 if (grp->attrs) {
43 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
Guenter Roeckda4759c2015-03-12 09:58:26 -040044 umode_t mode = (*attr)->mode;
James Bottomley0f423892008-03-20 20:47:52 -050045
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070046 /*
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)
Tejun Heo324a56e2013-12-11 14:11:53 -050052 kernfs_remove_by_name(parent, (*attr)->name);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070053 if (grp->is_visible) {
54 mode = grp->is_visible(kobj, *attr, i);
55 if (!mode)
56 continue;
57 }
Vivien Didelotd8bf8c92015-03-12 09:58:27 -040058
59 WARN(mode & ~(SYSFS_PREALLOC | 0664),
60 "Attribute %s: Invalid permissions 0%o\n",
61 (*attr)->name, mode);
62
63 mode &= SYSFS_PREALLOC | 0664;
Tejun Heo324a56e2013-12-11 14:11:53 -050064 error = sysfs_add_file_mode_ns(parent, *attr, false,
Guenter Roeckda4759c2015-03-12 09:58:26 -040065 mode, NULL);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070066 if (unlikely(error))
67 break;
James Bottomley0f423892008-03-20 20:47:52 -050068 }
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070069 if (error) {
Robert ABEL9f70a402014-05-05 15:17:20 +020070 remove_files(parent, grp);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070071 goto exit;
72 }
James Bottomley0f423892008-03-20 20:47:52 -050073 }
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070074
75 if (grp->bin_attrs) {
Emilio López7f5028c2015-09-21 10:38:20 -030076 for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) {
77 umode_t mode = (*bin_attr)->attr.mode;
78
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070079 if (update)
Cody P Schaferaabaf4c2014-02-14 14:02:07 -080080 kernfs_remove_by_name(parent,
81 (*bin_attr)->attr.name);
Emilio López7f5028c2015-09-21 10:38:20 -030082 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;
Cody P Schaferaabaf4c2014-02-14 14:02:07 -080093 error = sysfs_add_file_mode_ns(parent,
94 &(*bin_attr)->attr, true,
Emilio López7f5028c2015-09-21 10:38:20 -030095 mode, NULL);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070096 if (error)
97 break;
98 }
99 if (error)
Robert ABEL9f70a402014-05-05 15:17:20 +0200100 remove_files(parent, grp);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -0700101 }
102exit:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 return error;
104}
105
106
James Bottomley0f423892008-03-20 20:47:52 -0500107static int internal_create_group(struct kobject *kobj, int update,
108 const struct attribute_group *grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109{
Tejun Heo324a56e2013-12-11 14:11:53 -0500110 struct kernfs_node *kn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 int error;
112
James Bottomley0f423892008-03-20 20:47:52 -0500113 BUG_ON(!kobj || (!update && !kobj->sd));
114
115 /* Updates may happen before the object has been instantiated */
116 if (unlikely(update && !kobj->sd))
117 return -EINVAL;
Oliver Schinagl388a8c32013-07-14 16:05:56 -0700118 if (!grp->attrs && !grp->bin_attrs) {
119 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
Javi Merinoadf305f2015-01-15 16:17:45 +0000120 kobj->name, grp->name ?: "");
Bruno Prémont5631f2c2012-04-03 09:59:48 +0200121 return -EINVAL;
122 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 if (grp->name) {
Tejun Heobb8b9d092013-12-11 16:02:55 -0500124 kn = kernfs_create_dir(kobj->sd, grp->name,
125 S_IRWXU | S_IRUGO | S_IXUGO, kobj);
Tejun Heo324a56e2013-12-11 14:11:53 -0500126 if (IS_ERR(kn)) {
127 if (PTR_ERR(kn) == -EEXIST)
Tejun Heo93b2b8e2013-11-28 14:54:15 -0500128 sysfs_warn_dup(kobj->sd, grp->name);
Tejun Heo324a56e2013-12-11 14:11:53 -0500129 return PTR_ERR(kn);
Tejun Heo93b2b8e2013-11-28 14:54:15 -0500130 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 } else
Tejun Heo324a56e2013-12-11 14:11:53 -0500132 kn = kobj->sd;
133 kernfs_get(kn);
134 error = create_files(kn, kobj, grp, update);
Tejun Heo608e2662007-06-14 04:27:22 +0900135 if (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 if (grp->name)
Tejun Heo324a56e2013-12-11 14:11:53 -0500137 kernfs_remove(kn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 }
Tejun Heo324a56e2013-12-11 14:11:53 -0500139 kernfs_put(kn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 return error;
141}
142
James Bottomley0f423892008-03-20 20:47:52 -0500143/**
144 * sysfs_create_group - given a directory kobject, create an attribute group
145 * @kobj: The kobject to create the group on
146 * @grp: The attribute group to create
147 *
148 * This function creates a group for the first time. It will explicitly
149 * warn and error if any of the attribute files being created already exist.
150 *
Antonio Ospiteed1dc8a82015-04-29 10:55:46 +0200151 * Returns 0 on success or error code on failure.
James Bottomley0f423892008-03-20 20:47:52 -0500152 */
153int sysfs_create_group(struct kobject *kobj,
154 const struct attribute_group *grp)
155{
156 return internal_create_group(kobj, 0, grp);
157}
Greg Kroah-Hartmand363bc52013-08-21 16:04:12 -0700158EXPORT_SYMBOL_GPL(sysfs_create_group);
James Bottomley0f423892008-03-20 20:47:52 -0500159
160/**
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700161 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
162 * @kobj: The kobject to create the group on
163 * @groups: The attribute groups to create, NULL terminated
164 *
165 * This function creates a bunch of attribute groups. If an error occurs when
166 * creating a group, all previously created groups will be removed, unwinding
167 * everything back to the original state when this function was called.
168 * It will explicitly warn and error if any of the attribute files being
169 * created already exist.
170 *
Antonio Ospiteed1dc8a82015-04-29 10:55:46 +0200171 * Returns 0 on success or error code from sysfs_create_group on failure.
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700172 */
173int sysfs_create_groups(struct kobject *kobj,
174 const struct attribute_group **groups)
175{
176 int error = 0;
177 int i;
178
179 if (!groups)
180 return 0;
181
182 for (i = 0; groups[i]; i++) {
183 error = sysfs_create_group(kobj, groups[i]);
184 if (error) {
185 while (--i >= 0)
186 sysfs_remove_group(kobj, groups[i]);
187 break;
188 }
189 }
190 return error;
191}
192EXPORT_SYMBOL_GPL(sysfs_create_groups);
193
194/**
Robert P. J. Day1f8e1cd2011-05-07 17:18:20 -0400195 * sysfs_update_group - given a directory kobject, update an attribute group
196 * @kobj: The kobject to update the group on
197 * @grp: The attribute group to update
James Bottomley0f423892008-03-20 20:47:52 -0500198 *
199 * This function updates an attribute group. Unlike
200 * sysfs_create_group(), it will explicitly not warn or error if any
201 * of the attribute files being created already exist. Furthermore,
202 * if the visibility of the files has changed through the is_visible()
203 * callback, it will update the permissions and add or remove the
204 * relevant files.
205 *
206 * The primary use for this function is to call it after making a change
207 * that affects group visibility.
208 *
Antonio Ospiteed1dc8a82015-04-29 10:55:46 +0200209 * Returns 0 on success or error code on failure.
James Bottomley0f423892008-03-20 20:47:52 -0500210 */
211int sysfs_update_group(struct kobject *kobj,
212 const struct attribute_group *grp)
213{
214 return internal_create_group(kobj, 1, grp);
215}
Greg Kroah-Hartmand363bc52013-08-21 16:04:12 -0700216EXPORT_SYMBOL_GPL(sysfs_update_group);
James Bottomley0f423892008-03-20 20:47:52 -0500217
Greg Kroah-Hartmanf9ae4432013-08-21 16:12:34 -0700218/**
219 * sysfs_remove_group: remove a group from a kobject
220 * @kobj: kobject to remove the group from
221 * @grp: group to remove
222 *
223 * This function removes a group of attributes from a kobject. The attributes
224 * previously have to have been created for this group, otherwise it will fail.
225 */
Greg Kroah-Hartman995d8ed2013-08-21 16:07:29 -0700226void sysfs_remove_group(struct kobject *kobj,
227 const struct attribute_group *grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228{
Tejun Heo324a56e2013-12-11 14:11:53 -0500229 struct kernfs_node *parent = kobj->sd;
230 struct kernfs_node *kn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
James Morris057f6c02007-04-26 00:12:05 -0700232 if (grp->name) {
Tejun Heo324a56e2013-12-11 14:11:53 -0500233 kn = kernfs_find_and_get(parent, grp->name);
234 if (!kn) {
235 WARN(!kn, KERN_WARNING
Greg Kroah-Hartman16aebf12013-08-21 16:10:02 -0700236 "sysfs group %p not found for kobject '%s'\n",
237 grp, kobject_name(kobj));
Greg Kroah-Hartman969affd2008-02-07 11:58:54 -0500238 return;
239 }
Tejun Heoccf73cf2013-11-28 14:54:30 -0500240 } else {
Tejun Heo324a56e2013-12-11 14:11:53 -0500241 kn = parent;
242 kernfs_get(kn);
Tejun Heoccf73cf2013-11-28 14:54:30 -0500243 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
Robert ABEL9f70a402014-05-05 15:17:20 +0200245 remove_files(kn, grp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 if (grp->name)
Tejun Heo324a56e2013-12-11 14:11:53 -0500247 kernfs_remove(kn);
Tejun Heo608e2662007-06-14 04:27:22 +0900248
Tejun Heo324a56e2013-12-11 14:11:53 -0500249 kernfs_put(kn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250}
Greg Kroah-Hartmand363bc52013-08-21 16:04:12 -0700251EXPORT_SYMBOL_GPL(sysfs_remove_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
Alan Stern69d44ff2010-09-25 23:34:22 +0200253/**
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700254 * sysfs_remove_groups - remove a list of groups
255 *
Greg Kroah-Hartmanf9ae4432013-08-21 16:12:34 -0700256 * @kobj: The kobject for the groups to be removed from
257 * @groups: NULL terminated list of groups to be removed
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700258 *
Greg Kroah-Hartman09239ed2013-08-22 09:23:28 -0700259 * If groups is not NULL, remove the specified groups from the kobject.
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700260 */
261void sysfs_remove_groups(struct kobject *kobj,
262 const struct attribute_group **groups)
263{
264 int i;
265
266 if (!groups)
267 return;
268 for (i = 0; groups[i]; i++)
269 sysfs_remove_group(kobj, groups[i]);
270}
271EXPORT_SYMBOL_GPL(sysfs_remove_groups);
272
273/**
Alan Stern69d44ff2010-09-25 23:34:22 +0200274 * sysfs_merge_group - merge files into a pre-existing attribute group.
275 * @kobj: The kobject containing the group.
276 * @grp: The files to create and the attribute group they belong to.
277 *
278 * This function returns an error if the group doesn't exist or any of the
279 * files already exist in that group, in which case none of the new files
280 * are created.
281 */
282int sysfs_merge_group(struct kobject *kobj,
283 const struct attribute_group *grp)
284{
Tejun Heo324a56e2013-12-11 14:11:53 -0500285 struct kernfs_node *parent;
Alan Stern69d44ff2010-09-25 23:34:22 +0200286 int error = 0;
287 struct attribute *const *attr;
288 int i;
289
Tejun Heo324a56e2013-12-11 14:11:53 -0500290 parent = kernfs_find_and_get(kobj->sd, grp->name);
291 if (!parent)
Alan Stern69d44ff2010-09-25 23:34:22 +0200292 return -ENOENT;
293
294 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
Tejun Heo324a56e2013-12-11 14:11:53 -0500295 error = sysfs_add_file(parent, *attr, false);
Alan Stern69d44ff2010-09-25 23:34:22 +0200296 if (error) {
297 while (--i >= 0)
Tejun Heo324a56e2013-12-11 14:11:53 -0500298 kernfs_remove_by_name(parent, (*--attr)->name);
Alan Stern69d44ff2010-09-25 23:34:22 +0200299 }
Tejun Heo324a56e2013-12-11 14:11:53 -0500300 kernfs_put(parent);
Alan Stern69d44ff2010-09-25 23:34:22 +0200301
302 return error;
303}
304EXPORT_SYMBOL_GPL(sysfs_merge_group);
305
306/**
307 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
308 * @kobj: The kobject containing the group.
309 * @grp: The files to remove and the attribute group they belong to.
310 */
311void sysfs_unmerge_group(struct kobject *kobj,
312 const struct attribute_group *grp)
313{
Tejun Heo324a56e2013-12-11 14:11:53 -0500314 struct kernfs_node *parent;
Alan Stern69d44ff2010-09-25 23:34:22 +0200315 struct attribute *const *attr;
316
Tejun Heo324a56e2013-12-11 14:11:53 -0500317 parent = kernfs_find_and_get(kobj->sd, grp->name);
318 if (parent) {
Alan Stern69d44ff2010-09-25 23:34:22 +0200319 for (attr = grp->attrs; *attr; ++attr)
Tejun Heo324a56e2013-12-11 14:11:53 -0500320 kernfs_remove_by_name(parent, (*attr)->name);
321 kernfs_put(parent);
Alan Stern69d44ff2010-09-25 23:34:22 +0200322 }
323}
324EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
325
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100326/**
327 * sysfs_add_link_to_group - add a symlink to an attribute group.
328 * @kobj: The kobject containing the group.
329 * @group_name: The name of the group.
330 * @target: The target kobject of the symlink to create.
331 * @link_name: The name of the symlink to create.
332 */
333int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
334 struct kobject *target, const char *link_name)
335{
Tejun Heo324a56e2013-12-11 14:11:53 -0500336 struct kernfs_node *parent;
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100337 int error = 0;
338
Tejun Heo324a56e2013-12-11 14:11:53 -0500339 parent = kernfs_find_and_get(kobj->sd, group_name);
340 if (!parent)
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100341 return -ENOENT;
342
Tejun Heo324a56e2013-12-11 14:11:53 -0500343 error = sysfs_create_link_sd(parent, target, link_name);
344 kernfs_put(parent);
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100345
346 return error;
347}
348EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
349
350/**
351 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
352 * @kobj: The kobject containing the group.
353 * @group_name: The name of the group.
354 * @link_name: The name of the symlink to remove.
355 */
356void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
357 const char *link_name)
358{
Tejun Heo324a56e2013-12-11 14:11:53 -0500359 struct kernfs_node *parent;
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100360
Tejun Heo324a56e2013-12-11 14:11:53 -0500361 parent = kernfs_find_and_get(kobj->sd, group_name);
362 if (parent) {
363 kernfs_remove_by_name(parent, link_name);
364 kernfs_put(parent);
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100365 }
366}
367EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
Jarkko Sakkinen37c1c042015-04-22 19:36:06 +0300368
369/**
370 * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
371 * to a group or an attribute
372 * @kobj: The kobject containing the group.
373 * @target_kobj: The target kobject.
374 * @target_name: The name of the target group or attribute.
375 */
376int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
377 struct kobject *target_kobj,
378 const char *target_name)
379{
380 struct kernfs_node *target;
381 struct kernfs_node *entry;
382 struct kernfs_node *link;
383
384 /*
385 * We don't own @target_kobj and it may be removed at any time.
386 * Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
387 * for details.
388 */
389 spin_lock(&sysfs_symlink_target_lock);
390 target = target_kobj->sd;
391 if (target)
392 kernfs_get(target);
393 spin_unlock(&sysfs_symlink_target_lock);
394 if (!target)
395 return -ENOENT;
396
397 entry = kernfs_find_and_get(target_kobj->sd, target_name);
398 if (!entry) {
399 kernfs_put(target);
400 return -ENOENT;
401 }
402
403 link = kernfs_create_link(kobj->sd, target_name, entry);
404 if (IS_ERR(link) && PTR_ERR(link) == -EEXIST)
405 sysfs_warn_dup(kobj->sd, target_name);
406
407 kernfs_put(entry);
408 kernfs_put(target);
409 return IS_ERR(link) ? PTR_ERR(link) : 0;
410}
411EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);