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 kernfs_remove_by_name(dir_sd, (*attr)->name);
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 kernfs_remove_by_name(dir_sd, (*attr)->name);
53 if (grp->is_visible) {
54 mode = grp->is_visible(kobj, *attr, i);
58 error = sysfs_add_file_mode_ns(dir_sd, *attr, false,
65 remove_files(dir_sd, kobj, grp);
71 for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
73 sysfs_remove_bin_file(kobj, *bin_attr);
74 error = sysfs_create_bin_file(kobj, *bin_attr);
79 remove_files(dir_sd, kobj, grp);
86 static int internal_create_group(struct kobject *kobj, int update,
87 const struct attribute_group *grp)
89 struct sysfs_dirent *sd;
92 BUG_ON(!kobj || (!update && !kobj->sd));
94 /* Updates may happen before the object has been instantiated */
95 if (unlikely(update && !kobj->sd))
97 if (!grp->attrs && !grp->bin_attrs) {
98 WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
99 kobj->name, grp->name ? "" : grp->name);
103 sd = kernfs_create_dir(kobj->sd, grp->name, kobj);
105 if (PTR_ERR(sd) == -EEXIST)
106 sysfs_warn_dup(kobj->sd, grp->name);
112 error = create_files(sd, kobj, grp, update);
122 * sysfs_create_group - given a directory kobject, create an attribute group
123 * @kobj: The kobject to create the group on
124 * @grp: The attribute group to create
126 * This function creates a group for the first time. It will explicitly
127 * warn and error if any of the attribute files being created already exist.
129 * Returns 0 on success or error.
131 int sysfs_create_group(struct kobject *kobj,
132 const struct attribute_group *grp)
134 return internal_create_group(kobj, 0, grp);
136 EXPORT_SYMBOL_GPL(sysfs_create_group);
139 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
140 * @kobj: The kobject to create the group on
141 * @groups: The attribute groups to create, NULL terminated
143 * This function creates a bunch of attribute groups. If an error occurs when
144 * creating a group, all previously created groups will be removed, unwinding
145 * everything back to the original state when this function was called.
146 * It will explicitly warn and error if any of the attribute files being
147 * created already exist.
149 * Returns 0 on success or error code from sysfs_create_group on error.
151 int sysfs_create_groups(struct kobject *kobj,
152 const struct attribute_group **groups)
160 for (i = 0; groups[i]; i++) {
161 error = sysfs_create_group(kobj, groups[i]);
164 sysfs_remove_group(kobj, groups[i]);
170 EXPORT_SYMBOL_GPL(sysfs_create_groups);
173 * sysfs_update_group - given a directory kobject, update an attribute group
174 * @kobj: The kobject to update the group on
175 * @grp: The attribute group to update
177 * This function updates an attribute group. Unlike
178 * sysfs_create_group(), it will explicitly not warn or error if any
179 * of the attribute files being created already exist. Furthermore,
180 * if the visibility of the files has changed through the is_visible()
181 * callback, it will update the permissions and add or remove the
184 * The primary use for this function is to call it after making a change
185 * that affects group visibility.
187 * Returns 0 on success or error.
189 int sysfs_update_group(struct kobject *kobj,
190 const struct attribute_group *grp)
192 return internal_create_group(kobj, 1, grp);
194 EXPORT_SYMBOL_GPL(sysfs_update_group);
197 * sysfs_remove_group: remove a group from a kobject
198 * @kobj: kobject to remove the group from
199 * @grp: group to remove
201 * This function removes a group of attributes from a kobject. The attributes
202 * previously have to have been created for this group, otherwise it will fail.
204 void sysfs_remove_group(struct kobject *kobj,
205 const struct attribute_group *grp)
207 struct sysfs_dirent *dir_sd = kobj->sd;
208 struct sysfs_dirent *sd;
211 sd = sysfs_get_dirent(dir_sd, grp->name);
213 WARN(!sd, KERN_WARNING
214 "sysfs group %p not found for kobject '%s'\n",
215 grp, kobject_name(kobj));
219 sd = sysfs_get(dir_sd);
221 remove_files(sd, kobj, grp);
227 EXPORT_SYMBOL_GPL(sysfs_remove_group);
230 * sysfs_remove_groups - remove a list of groups
232 * @kobj: The kobject for the groups to be removed from
233 * @groups: NULL terminated list of groups to be removed
235 * If groups is not NULL, remove the specified groups from the kobject.
237 void sysfs_remove_groups(struct kobject *kobj,
238 const struct attribute_group **groups)
244 for (i = 0; groups[i]; i++)
245 sysfs_remove_group(kobj, groups[i]);
247 EXPORT_SYMBOL_GPL(sysfs_remove_groups);
250 * sysfs_merge_group - merge files into a pre-existing attribute group.
251 * @kobj: The kobject containing the group.
252 * @grp: The files to create and the attribute group they belong to.
254 * This function returns an error if the group doesn't exist or any of the
255 * files already exist in that group, in which case none of the new files
258 int sysfs_merge_group(struct kobject *kobj,
259 const struct attribute_group *grp)
261 struct sysfs_dirent *dir_sd;
263 struct attribute *const *attr;
266 dir_sd = sysfs_get_dirent(kobj->sd, grp->name);
270 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
271 error = sysfs_add_file(dir_sd, *attr, false);
274 kernfs_remove_by_name(dir_sd, (*--attr)->name);
280 EXPORT_SYMBOL_GPL(sysfs_merge_group);
283 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
284 * @kobj: The kobject containing the group.
285 * @grp: The files to remove and the attribute group they belong to.
287 void sysfs_unmerge_group(struct kobject *kobj,
288 const struct attribute_group *grp)
290 struct sysfs_dirent *dir_sd;
291 struct attribute *const *attr;
293 dir_sd = sysfs_get_dirent(kobj->sd, grp->name);
295 for (attr = grp->attrs; *attr; ++attr)
296 kernfs_remove_by_name(dir_sd, (*attr)->name);
300 EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
303 * sysfs_add_link_to_group - add a symlink to an attribute group.
304 * @kobj: The kobject containing the group.
305 * @group_name: The name of the group.
306 * @target: The target kobject of the symlink to create.
307 * @link_name: The name of the symlink to create.
309 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
310 struct kobject *target, const char *link_name)
312 struct sysfs_dirent *dir_sd;
315 dir_sd = sysfs_get_dirent(kobj->sd, group_name);
319 error = sysfs_create_link_sd(dir_sd, target, link_name);
324 EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
327 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
328 * @kobj: The kobject containing the group.
329 * @group_name: The name of the group.
330 * @link_name: The name of the symlink to remove.
332 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
333 const char *link_name)
335 struct sysfs_dirent *dir_sd;
337 dir_sd = sysfs_get_dirent(kobj->sd, group_name);
339 kernfs_remove_by_name(dir_sd, link_name);
343 EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);