2 * fs/sysfs/group.c - Operations for adding/removing multiple files at once.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2013 Greg Kroah-Hartman
7 * Copyright (c) 2013 The Linux Foundation
9 * This file is released undert the GPL v2.
13 #include <linux/kobject.h>
14 #include <linux/module.h>
15 #include <linux/dcache.h>
16 #include <linux/namei.h>
17 #include <linux/err.h>
21 static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
22 const struct attribute_group *grp)
24 struct attribute *const *attr;
25 struct bin_attribute *const *bin_attr;
28 for (attr = grp->attrs; *attr; attr++)
29 sysfs_hash_and_remove(dir_sd, (*attr)->name, NULL);
31 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
32 sysfs_remove_bin_file(kobj, *bin_attr);
35 static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
36 const struct attribute_group *grp, int update)
38 struct attribute *const *attr;
39 struct bin_attribute *const *bin_attr;
43 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
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.
52 sysfs_hash_and_remove(dir_sd, (*attr)->name,
54 if (grp->is_visible) {
55 mode = grp->is_visible(kobj, *attr, i);
59 error = sysfs_add_file_mode_ns(dir_sd, *attr,
67 remove_files(dir_sd, kobj, grp);
73 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
75 sysfs_remove_bin_file(kobj, *bin_attr);
76 error = sysfs_create_bin_file(kobj, *bin_attr);
81 remove_files(dir_sd, kobj, grp);
88 static int internal_create_group(struct kobject *kobj, int update,
89 const struct attribute_group *grp)
91 struct sysfs_dirent *sd;
94 BUG_ON(!kobj || (!update && !kobj->sd));
96 /* Updates may happen before the object has been instantiated */
97 if (unlikely(update && !kobj->sd))
99 if (!grp->attrs && !grp->bin_attrs) {
100 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
101 kobj->name, grp->name ? "" : grp->name);
105 error = sysfs_create_subdir(kobj, grp->name, &sd);
111 error = create_files(sd, kobj, grp, update);
121 * sysfs_create_group - given a directory kobject, create an attribute group
122 * @kobj: The kobject to create the group on
123 * @grp: The attribute group to create
125 * This function creates a group for the first time. It will explicitly
126 * warn and error if any of the attribute files being created already exist.
128 * Returns 0 on success or error.
130 int sysfs_create_group(struct kobject *kobj,
131 const struct attribute_group *grp)
133 return internal_create_group(kobj, 0, grp);
135 EXPORT_SYMBOL_GPL(sysfs_create_group);
138 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
139 * @kobj: The kobject to create the group on
140 * @groups: The attribute groups to create, NULL terminated
142 * This function creates a bunch of attribute groups. If an error occurs when
143 * creating a group, all previously created groups will be removed, unwinding
144 * everything back to the original state when this function was called.
145 * It will explicitly warn and error if any of the attribute files being
146 * created already exist.
148 * Returns 0 on success or error code from sysfs_create_group on error.
150 int sysfs_create_groups(struct kobject *kobj,
151 const struct attribute_group **groups)
159 for (i = 0; groups[i]; i++) {
160 error = sysfs_create_group(kobj, groups[i]);
163 sysfs_remove_group(kobj, groups[i]);
169 EXPORT_SYMBOL_GPL(sysfs_create_groups);
172 * sysfs_update_group - given a directory kobject, update an attribute group
173 * @kobj: The kobject to update the group on
174 * @grp: The attribute group to update
176 * This function updates an attribute group. Unlike
177 * sysfs_create_group(), it will explicitly not warn or error if any
178 * of the attribute files being created already exist. Furthermore,
179 * if the visibility of the files has changed through the is_visible()
180 * callback, it will update the permissions and add or remove the
183 * The primary use for this function is to call it after making a change
184 * that affects group visibility.
186 * Returns 0 on success or error.
188 int sysfs_update_group(struct kobject *kobj,
189 const struct attribute_group *grp)
191 return internal_create_group(kobj, 1, grp);
193 EXPORT_SYMBOL_GPL(sysfs_update_group);
196 * sysfs_remove_group: remove a group from a kobject
197 * @kobj: kobject to remove the group from
198 * @grp: group to remove
200 * This function removes a group of attributes from a kobject. The attributes
201 * previously have to have been created for this group, otherwise it will fail.
203 void sysfs_remove_group(struct kobject *kobj,
204 const struct attribute_group *grp)
206 struct sysfs_dirent *dir_sd = kobj->sd;
207 struct sysfs_dirent *sd;
210 sd = sysfs_get_dirent(dir_sd, grp->name);
212 WARN(!sd, KERN_WARNING
213 "sysfs group %p not found for kobject '%s'\n",
214 grp, kobject_name(kobj));
218 sd = sysfs_get(dir_sd);
220 remove_files(sd, kobj, grp);
226 EXPORT_SYMBOL_GPL(sysfs_remove_group);
229 * sysfs_remove_groups - remove a list of groups
231 * @kobj: The kobject for the groups to be removed from
232 * @groups: NULL terminated list of groups to be removed
234 * If groups is not NULL, remove the specified groups from the kobject.
236 void sysfs_remove_groups(struct kobject *kobj,
237 const struct attribute_group **groups)
243 for (i = 0; groups[i]; i++)
244 sysfs_remove_group(kobj, groups[i]);
246 EXPORT_SYMBOL_GPL(sysfs_remove_groups);
249 * sysfs_merge_group - merge files into a pre-existing attribute group.
250 * @kobj: The kobject containing the group.
251 * @grp: The files to create and the attribute group they belong to.
253 * This function returns an error if the group doesn't exist or any of the
254 * files already exist in that group, in which case none of the new files
257 int sysfs_merge_group(struct kobject *kobj,
258 const struct attribute_group *grp)
260 struct sysfs_dirent *dir_sd;
262 struct attribute *const *attr;
265 dir_sd = sysfs_get_dirent(kobj->sd, grp->name);
269 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
270 error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
273 sysfs_hash_and_remove(dir_sd, (*--attr)->name, NULL);
279 EXPORT_SYMBOL_GPL(sysfs_merge_group);
282 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
283 * @kobj: The kobject containing the group.
284 * @grp: The files to remove and the attribute group they belong to.
286 void sysfs_unmerge_group(struct kobject *kobj,
287 const struct attribute_group *grp)
289 struct sysfs_dirent *dir_sd;
290 struct attribute *const *attr;
292 dir_sd = sysfs_get_dirent(kobj->sd, grp->name);
294 for (attr = grp->attrs; *attr; ++attr)
295 sysfs_hash_and_remove(dir_sd, (*attr)->name, NULL);
299 EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
302 * sysfs_add_link_to_group - add a symlink to an attribute group.
303 * @kobj: The kobject containing the group.
304 * @group_name: The name of the group.
305 * @target: The target kobject of the symlink to create.
306 * @link_name: The name of the symlink to create.
308 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
309 struct kobject *target, const char *link_name)
311 struct sysfs_dirent *dir_sd;
314 dir_sd = sysfs_get_dirent(kobj->sd, group_name);
318 error = sysfs_create_link_sd(dir_sd, target, link_name);
323 EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
326 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
327 * @kobj: The kobject containing the group.
328 * @group_name: The name of the group.
329 * @link_name: The name of the symlink to remove.
331 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
332 const char *link_name)
334 struct sysfs_dirent *dir_sd;
336 dir_sd = sysfs_get_dirent(kobj->sd, group_name);
338 sysfs_hash_and_remove(dir_sd, link_name, NULL);
342 EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);