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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++) {
44 umode_t mode = 0;
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 }
Tejun Heo324a56e2013-12-11 14:11:53 -050058 error = sysfs_add_file_mode_ns(parent, *attr, false,
Tejun Heo58292cbe2013-09-11 22:29:04 -040059 (*attr)->mode | mode,
60 NULL);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070061 if (unlikely(error))
62 break;
James Bottomley0f423892008-03-20 20:47:52 -050063 }
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070064 if (error) {
Robert ABEL9f70a402014-05-05 15:17:20 +020065 remove_files(parent, grp);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070066 goto exit;
67 }
James Bottomley0f423892008-03-20 20:47:52 -050068 }
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070069
70 if (grp->bin_attrs) {
71 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
72 if (update)
Cody P Schaferaabaf4c2014-02-14 14:02:07 -080073 kernfs_remove_by_name(parent,
74 (*bin_attr)->attr.name);
75 error = sysfs_add_file_mode_ns(parent,
76 &(*bin_attr)->attr, true,
77 (*bin_attr)->attr.mode, NULL);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070078 if (error)
79 break;
80 }
81 if (error)
Robert ABEL9f70a402014-05-05 15:17:20 +020082 remove_files(parent, grp);
Greg Kroah-Hartman6ab9cea2013-07-14 16:05:55 -070083 }
84exit:
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 return error;
86}
87
88
James Bottomley0f423892008-03-20 20:47:52 -050089static int internal_create_group(struct kobject *kobj, int update,
90 const struct attribute_group *grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
Tejun Heo324a56e2013-12-11 14:11:53 -050092 struct kernfs_node *kn;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 int error;
94
James Bottomley0f423892008-03-20 20:47:52 -050095 BUG_ON(!kobj || (!update && !kobj->sd));
96
97 /* Updates may happen before the object has been instantiated */
98 if (unlikely(update && !kobj->sd))
99 return -EINVAL;
Oliver Schinagl388a8c32013-07-14 16:05:56 -0700100 if (!grp->attrs && !grp->bin_attrs) {
101 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
Bruno Prémont5631f2c2012-04-03 09:59:48 +0200102 kobj->name, grp->name ? "" : grp->name);
103 return -EINVAL;
104 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 if (grp->name) {
Tejun Heobb8b9d092013-12-11 16:02:55 -0500106 kn = kernfs_create_dir(kobj->sd, grp->name,
107 S_IRWXU | S_IRUGO | S_IXUGO, kobj);
Tejun Heo324a56e2013-12-11 14:11:53 -0500108 if (IS_ERR(kn)) {
109 if (PTR_ERR(kn) == -EEXIST)
Tejun Heo93b2b8e2013-11-28 14:54:15 -0500110 sysfs_warn_dup(kobj->sd, grp->name);
Tejun Heo324a56e2013-12-11 14:11:53 -0500111 return PTR_ERR(kn);
Tejun Heo93b2b8e2013-11-28 14:54:15 -0500112 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 } else
Tejun Heo324a56e2013-12-11 14:11:53 -0500114 kn = kobj->sd;
115 kernfs_get(kn);
116 error = create_files(kn, kobj, grp, update);
Tejun Heo608e2662007-06-14 04:27:22 +0900117 if (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 if (grp->name)
Tejun Heo324a56e2013-12-11 14:11:53 -0500119 kernfs_remove(kn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 }
Tejun Heo324a56e2013-12-11 14:11:53 -0500121 kernfs_put(kn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 return error;
123}
124
James Bottomley0f423892008-03-20 20:47:52 -0500125/**
126 * sysfs_create_group - given a directory kobject, create an attribute group
127 * @kobj: The kobject to create the group on
128 * @grp: The attribute group to create
129 *
130 * This function creates a group for the first time. It will explicitly
131 * warn and error if any of the attribute files being created already exist.
132 *
133 * Returns 0 on success or error.
134 */
135int sysfs_create_group(struct kobject *kobj,
136 const struct attribute_group *grp)
137{
138 return internal_create_group(kobj, 0, grp);
139}
Greg Kroah-Hartmand363bc52013-08-21 16:04:12 -0700140EXPORT_SYMBOL_GPL(sysfs_create_group);
James Bottomley0f423892008-03-20 20:47:52 -0500141
142/**
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700143 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
144 * @kobj: The kobject to create the group on
145 * @groups: The attribute groups to create, NULL terminated
146 *
147 * This function creates a bunch of attribute groups. If an error occurs when
148 * creating a group, all previously created groups will be removed, unwinding
149 * everything back to the original state when this function was called.
150 * It will explicitly warn and error if any of the attribute files being
151 * created already exist.
152 *
Greg Kroah-Hartman09239ed2013-08-22 09:23:28 -0700153 * Returns 0 on success or error code from sysfs_create_group on error.
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700154 */
155int sysfs_create_groups(struct kobject *kobj,
156 const struct attribute_group **groups)
157{
158 int error = 0;
159 int i;
160
161 if (!groups)
162 return 0;
163
164 for (i = 0; groups[i]; i++) {
165 error = sysfs_create_group(kobj, groups[i]);
166 if (error) {
167 while (--i >= 0)
168 sysfs_remove_group(kobj, groups[i]);
169 break;
170 }
171 }
172 return error;
173}
174EXPORT_SYMBOL_GPL(sysfs_create_groups);
175
176/**
Robert P. J. Day1f8e1cd2011-05-07 17:18:20 -0400177 * sysfs_update_group - given a directory kobject, update an attribute group
178 * @kobj: The kobject to update the group on
179 * @grp: The attribute group to update
James Bottomley0f423892008-03-20 20:47:52 -0500180 *
181 * This function updates an attribute group. Unlike
182 * sysfs_create_group(), it will explicitly not warn or error if any
183 * of the attribute files being created already exist. Furthermore,
184 * if the visibility of the files has changed through the is_visible()
185 * callback, it will update the permissions and add or remove the
186 * relevant files.
187 *
188 * The primary use for this function is to call it after making a change
189 * that affects group visibility.
190 *
191 * Returns 0 on success or error.
192 */
193int sysfs_update_group(struct kobject *kobj,
194 const struct attribute_group *grp)
195{
196 return internal_create_group(kobj, 1, grp);
197}
Greg Kroah-Hartmand363bc52013-08-21 16:04:12 -0700198EXPORT_SYMBOL_GPL(sysfs_update_group);
James Bottomley0f423892008-03-20 20:47:52 -0500199
Greg Kroah-Hartmanf9ae4432013-08-21 16:12:34 -0700200/**
201 * sysfs_remove_group: remove a group from a kobject
202 * @kobj: kobject to remove the group from
203 * @grp: group to remove
204 *
205 * This function removes a group of attributes from a kobject. The attributes
206 * previously have to have been created for this group, otherwise it will fail.
207 */
Greg Kroah-Hartman995d8ed2013-08-21 16:07:29 -0700208void sysfs_remove_group(struct kobject *kobj,
209 const struct attribute_group *grp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210{
Tejun Heo324a56e2013-12-11 14:11:53 -0500211 struct kernfs_node *parent = kobj->sd;
212 struct kernfs_node *kn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
James Morris057f6c02007-04-26 00:12:05 -0700214 if (grp->name) {
Tejun Heo324a56e2013-12-11 14:11:53 -0500215 kn = kernfs_find_and_get(parent, grp->name);
216 if (!kn) {
217 WARN(!kn, KERN_WARNING
Greg Kroah-Hartman16aebf12013-08-21 16:10:02 -0700218 "sysfs group %p not found for kobject '%s'\n",
219 grp, kobject_name(kobj));
Greg Kroah-Hartman969affd2008-02-07 11:58:54 -0500220 return;
221 }
Tejun Heoccf73cf2013-11-28 14:54:30 -0500222 } else {
Tejun Heo324a56e2013-12-11 14:11:53 -0500223 kn = parent;
224 kernfs_get(kn);
Tejun Heoccf73cf2013-11-28 14:54:30 -0500225 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Robert ABEL9f70a402014-05-05 15:17:20 +0200227 remove_files(kn, grp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 if (grp->name)
Tejun Heo324a56e2013-12-11 14:11:53 -0500229 kernfs_remove(kn);
Tejun Heo608e2662007-06-14 04:27:22 +0900230
Tejun Heo324a56e2013-12-11 14:11:53 -0500231 kernfs_put(kn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232}
Greg Kroah-Hartmand363bc52013-08-21 16:04:12 -0700233EXPORT_SYMBOL_GPL(sysfs_remove_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Alan Stern69d44ff2010-09-25 23:34:22 +0200235/**
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700236 * sysfs_remove_groups - remove a list of groups
237 *
Greg Kroah-Hartmanf9ae4432013-08-21 16:12:34 -0700238 * @kobj: The kobject for the groups to be removed from
239 * @groups: NULL terminated list of groups to be removed
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700240 *
Greg Kroah-Hartman09239ed2013-08-22 09:23:28 -0700241 * If groups is not NULL, remove the specified groups from the kobject.
Greg Kroah-Hartman3e9b2ba2013-08-21 13:47:50 -0700242 */
243void sysfs_remove_groups(struct kobject *kobj,
244 const struct attribute_group **groups)
245{
246 int i;
247
248 if (!groups)
249 return;
250 for (i = 0; groups[i]; i++)
251 sysfs_remove_group(kobj, groups[i]);
252}
253EXPORT_SYMBOL_GPL(sysfs_remove_groups);
254
255/**
Alan Stern69d44ff2010-09-25 23:34:22 +0200256 * sysfs_merge_group - merge files into a pre-existing attribute group.
257 * @kobj: The kobject containing the group.
258 * @grp: The files to create and the attribute group they belong to.
259 *
260 * This function returns an error if the group doesn't exist or any of the
261 * files already exist in that group, in which case none of the new files
262 * are created.
263 */
264int sysfs_merge_group(struct kobject *kobj,
265 const struct attribute_group *grp)
266{
Tejun Heo324a56e2013-12-11 14:11:53 -0500267 struct kernfs_node *parent;
Alan Stern69d44ff2010-09-25 23:34:22 +0200268 int error = 0;
269 struct attribute *const *attr;
270 int i;
271
Tejun Heo324a56e2013-12-11 14:11:53 -0500272 parent = kernfs_find_and_get(kobj->sd, grp->name);
273 if (!parent)
Alan Stern69d44ff2010-09-25 23:34:22 +0200274 return -ENOENT;
275
276 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
Tejun Heo324a56e2013-12-11 14:11:53 -0500277 error = sysfs_add_file(parent, *attr, false);
Alan Stern69d44ff2010-09-25 23:34:22 +0200278 if (error) {
279 while (--i >= 0)
Tejun Heo324a56e2013-12-11 14:11:53 -0500280 kernfs_remove_by_name(parent, (*--attr)->name);
Alan Stern69d44ff2010-09-25 23:34:22 +0200281 }
Tejun Heo324a56e2013-12-11 14:11:53 -0500282 kernfs_put(parent);
Alan Stern69d44ff2010-09-25 23:34:22 +0200283
284 return error;
285}
286EXPORT_SYMBOL_GPL(sysfs_merge_group);
287
288/**
289 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
290 * @kobj: The kobject containing the group.
291 * @grp: The files to remove and the attribute group they belong to.
292 */
293void sysfs_unmerge_group(struct kobject *kobj,
294 const struct attribute_group *grp)
295{
Tejun Heo324a56e2013-12-11 14:11:53 -0500296 struct kernfs_node *parent;
Alan Stern69d44ff2010-09-25 23:34:22 +0200297 struct attribute *const *attr;
298
Tejun Heo324a56e2013-12-11 14:11:53 -0500299 parent = kernfs_find_and_get(kobj->sd, grp->name);
300 if (parent) {
Alan Stern69d44ff2010-09-25 23:34:22 +0200301 for (attr = grp->attrs; *attr; ++attr)
Tejun Heo324a56e2013-12-11 14:11:53 -0500302 kernfs_remove_by_name(parent, (*attr)->name);
303 kernfs_put(parent);
Alan Stern69d44ff2010-09-25 23:34:22 +0200304 }
305}
306EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
307
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100308/**
309 * sysfs_add_link_to_group - add a symlink to an attribute group.
310 * @kobj: The kobject containing the group.
311 * @group_name: The name of the group.
312 * @target: The target kobject of the symlink to create.
313 * @link_name: The name of the symlink to create.
314 */
315int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
316 struct kobject *target, const char *link_name)
317{
Tejun Heo324a56e2013-12-11 14:11:53 -0500318 struct kernfs_node *parent;
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100319 int error = 0;
320
Tejun Heo324a56e2013-12-11 14:11:53 -0500321 parent = kernfs_find_and_get(kobj->sd, group_name);
322 if (!parent)
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100323 return -ENOENT;
324
Tejun Heo324a56e2013-12-11 14:11:53 -0500325 error = sysfs_create_link_sd(parent, target, link_name);
326 kernfs_put(parent);
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100327
328 return error;
329}
330EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
331
332/**
333 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
334 * @kobj: The kobject containing the group.
335 * @group_name: The name of the group.
336 * @link_name: The name of the symlink to remove.
337 */
338void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
339 const char *link_name)
340{
Tejun Heo324a56e2013-12-11 14:11:53 -0500341 struct kernfs_node *parent;
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100342
Tejun Heo324a56e2013-12-11 14:11:53 -0500343 parent = kernfs_find_and_get(kobj->sd, group_name);
344 if (parent) {
345 kernfs_remove_by_name(parent, link_name);
346 kernfs_put(parent);
Rafael J. Wysocki0bb8f3d2013-01-25 21:51:13 +0100347 }
348}
349EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);