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 kernfs_node *parent, 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(parent, (*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 kernfs_node *parent, 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(parent, (*attr)->name);
53 if (grp->is_visible) {
54 mode = grp->is_visible(kobj, *attr, i);
58 error = sysfs_add_file_mode_ns(parent, *attr, false,
65 remove_files(parent, 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(parent, kobj, grp);
86 static int internal_create_group(struct kobject *kobj, int update,
87 const struct attribute_group *grp)
89 struct kernfs_node *kn;
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 kn = kernfs_create_dir(kobj->sd, grp->name,
104 S_IRWXU | S_IRUGO | S_IXUGO, kobj);
106 if (PTR_ERR(kn) == -EEXIST)
107 sysfs_warn_dup(kobj->sd, grp->name);
113 error = create_files(kn, kobj, grp, update);
123 * sysfs_create_group - given a directory kobject, create an attribute group
124 * @kobj: The kobject to create the group on
125 * @grp: The attribute group to create
127 * This function creates a group for the first time. It will explicitly
128 * warn and error if any of the attribute files being created already exist.
130 * Returns 0 on success or error.
132 int sysfs_create_group(struct kobject *kobj,
133 const struct attribute_group *grp)
135 return internal_create_group(kobj, 0, grp);
137 EXPORT_SYMBOL_GPL(sysfs_create_group);
140 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
141 * @kobj: The kobject to create the group on
142 * @groups: The attribute groups to create, NULL terminated
144 * This function creates a bunch of attribute groups. If an error occurs when
145 * creating a group, all previously created groups will be removed, unwinding
146 * everything back to the original state when this function was called.
147 * It will explicitly warn and error if any of the attribute files being
148 * created already exist.
150 * Returns 0 on success or error code from sysfs_create_group on error.
152 int sysfs_create_groups(struct kobject *kobj,
153 const struct attribute_group **groups)
161 for (i = 0; groups[i]; i++) {
162 error = sysfs_create_group(kobj, groups[i]);
165 sysfs_remove_group(kobj, groups[i]);
171 EXPORT_SYMBOL_GPL(sysfs_create_groups);
174 * sysfs_update_group - given a directory kobject, update an attribute group
175 * @kobj: The kobject to update the group on
176 * @grp: The attribute group to update
178 * This function updates an attribute group. Unlike
179 * sysfs_create_group(), it will explicitly not warn or error if any
180 * of the attribute files being created already exist. Furthermore,
181 * if the visibility of the files has changed through the is_visible()
182 * callback, it will update the permissions and add or remove the
185 * The primary use for this function is to call it after making a change
186 * that affects group visibility.
188 * Returns 0 on success or error.
190 int sysfs_update_group(struct kobject *kobj,
191 const struct attribute_group *grp)
193 return internal_create_group(kobj, 1, grp);
195 EXPORT_SYMBOL_GPL(sysfs_update_group);
198 * sysfs_remove_group: remove a group from a kobject
199 * @kobj: kobject to remove the group from
200 * @grp: group to remove
202 * This function removes a group of attributes from a kobject. The attributes
203 * previously have to have been created for this group, otherwise it will fail.
205 void sysfs_remove_group(struct kobject *kobj,
206 const struct attribute_group *grp)
208 struct kernfs_node *parent = kobj->sd;
209 struct kernfs_node *kn;
212 kn = kernfs_find_and_get(parent, grp->name);
214 WARN(!kn, KERN_WARNING
215 "sysfs group %p not found for kobject '%s'\n",
216 grp, kobject_name(kobj));
224 remove_files(kn, kobj, grp);
230 EXPORT_SYMBOL_GPL(sysfs_remove_group);
233 * sysfs_remove_groups - remove a list of groups
235 * @kobj: The kobject for the groups to be removed from
236 * @groups: NULL terminated list of groups to be removed
238 * If groups is not NULL, remove the specified groups from the kobject.
240 void sysfs_remove_groups(struct kobject *kobj,
241 const struct attribute_group **groups)
247 for (i = 0; groups[i]; i++)
248 sysfs_remove_group(kobj, groups[i]);
250 EXPORT_SYMBOL_GPL(sysfs_remove_groups);
253 * sysfs_merge_group - merge files into a pre-existing attribute group.
254 * @kobj: The kobject containing the group.
255 * @grp: The files to create and the attribute group they belong to.
257 * This function returns an error if the group doesn't exist or any of the
258 * files already exist in that group, in which case none of the new files
261 int sysfs_merge_group(struct kobject *kobj,
262 const struct attribute_group *grp)
264 struct kernfs_node *parent;
266 struct attribute *const *attr;
269 parent = kernfs_find_and_get(kobj->sd, grp->name);
273 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
274 error = sysfs_add_file(parent, *attr, false);
277 kernfs_remove_by_name(parent, (*--attr)->name);
283 EXPORT_SYMBOL_GPL(sysfs_merge_group);
286 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
287 * @kobj: The kobject containing the group.
288 * @grp: The files to remove and the attribute group they belong to.
290 void sysfs_unmerge_group(struct kobject *kobj,
291 const struct attribute_group *grp)
293 struct kernfs_node *parent;
294 struct attribute *const *attr;
296 parent = kernfs_find_and_get(kobj->sd, grp->name);
298 for (attr = grp->attrs; *attr; ++attr)
299 kernfs_remove_by_name(parent, (*attr)->name);
303 EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
306 * sysfs_add_link_to_group - add a symlink to an attribute group.
307 * @kobj: The kobject containing the group.
308 * @group_name: The name of the group.
309 * @target: The target kobject of the symlink to create.
310 * @link_name: The name of the symlink to create.
312 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
313 struct kobject *target, const char *link_name)
315 struct kernfs_node *parent;
318 parent = kernfs_find_and_get(kobj->sd, group_name);
322 error = sysfs_create_link_sd(parent, target, link_name);
327 EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
330 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
331 * @kobj: The kobject containing the group.
332 * @group_name: The name of the group.
333 * @link_name: The name of the symlink to remove.
335 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
336 const char *link_name)
338 struct kernfs_node *parent;
340 parent = kernfs_find_and_get(kobj->sd, group_name);
342 kernfs_remove_by_name(parent, link_name);
346 EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);