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
7 * This file is released undert the GPL v2.
11 #include <linux/kobject.h>
12 #include <linux/module.h>
13 #include <linux/dcache.h>
14 #include <linux/namei.h>
15 #include <linux/err.h>
19 static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
20 const struct attribute_group *grp)
22 struct attribute *const* attr;
25 for (i = 0, attr = grp->attrs; *attr; i++, attr++)
26 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
29 static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
30 const struct attribute_group *grp, int update)
32 struct attribute *const* attr;
35 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
38 /* in update mode, we're changing the permissions or
39 * visibility. Do this by first removing then
40 * re-adding (if required) the file */
42 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
43 if (grp->is_visible) {
44 mode = grp->is_visible(kobj, *attr, i);
48 error = sysfs_add_file_mode(dir_sd, *attr, SYSFS_KOBJ_ATTR,
49 (*attr)->mode | mode);
54 remove_files(dir_sd, kobj, grp);
59 static int internal_create_group(struct kobject *kobj, int update,
60 const struct attribute_group *grp)
62 struct sysfs_dirent *sd;
65 BUG_ON(!kobj || (!update && !kobj->sd));
67 /* Updates may happen before the object has been instantiated */
68 if (unlikely(update && !kobj->sd))
71 WARN(1, "sysfs: attrs not set by subsystem for group: %s/%s\n",
72 kobj->name, grp->name ? "" : grp->name);
76 error = sysfs_create_subdir(kobj, grp->name, &sd);
82 error = create_files(sd, kobj, grp, update);
85 sysfs_remove_subdir(sd);
92 * sysfs_create_group - given a directory kobject, create an attribute group
93 * @kobj: The kobject to create the group on
94 * @grp: The attribute group to create
96 * This function creates a group for the first time. It will explicitly
97 * warn and error if any of the attribute files being created already exist.
99 * Returns 0 on success or error.
101 int sysfs_create_group(struct kobject *kobj,
102 const struct attribute_group *grp)
104 return internal_create_group(kobj, 0, grp);
108 * sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
109 * @kobj: The kobject to create the group on
110 * @groups: The attribute groups to create, NULL terminated
112 * This function creates a bunch of attribute groups. If an error occurs when
113 * creating a group, all previously created groups will be removed, unwinding
114 * everything back to the original state when this function was called.
115 * It will explicitly warn and error if any of the attribute files being
116 * created already exist.
118 * Returns 0 on success or error code from sysfs_create_groups on error.
120 int sysfs_create_groups(struct kobject *kobj,
121 const struct attribute_group **groups)
129 for (i = 0; groups[i]; i++) {
130 error = sysfs_create_group(kobj, groups[i]);
133 sysfs_remove_group(kobj, groups[i]);
139 EXPORT_SYMBOL_GPL(sysfs_create_groups);
142 * sysfs_update_group - given a directory kobject, update an attribute group
143 * @kobj: The kobject to update the group on
144 * @grp: The attribute group to update
146 * This function updates an attribute group. Unlike
147 * sysfs_create_group(), it will explicitly not warn or error if any
148 * of the attribute files being created already exist. Furthermore,
149 * if the visibility of the files has changed through the is_visible()
150 * callback, it will update the permissions and add or remove the
153 * The primary use for this function is to call it after making a change
154 * that affects group visibility.
156 * Returns 0 on success or error.
158 int sysfs_update_group(struct kobject *kobj,
159 const struct attribute_group *grp)
161 return internal_create_group(kobj, 1, grp);
166 void sysfs_remove_group(struct kobject * kobj,
167 const struct attribute_group * grp)
169 struct sysfs_dirent *dir_sd = kobj->sd;
170 struct sysfs_dirent *sd;
173 sd = sysfs_get_dirent(dir_sd, NULL, grp->name);
175 WARN(!sd, KERN_WARNING "sysfs group %p not found for "
176 "kobject '%s'\n", grp, kobject_name(kobj));
180 sd = sysfs_get(dir_sd);
182 remove_files(sd, kobj, grp);
184 sysfs_remove_subdir(sd);
190 * sysfs_remove_groups - remove a list of groups
192 * kobj: The kobject for the groups to be removed from
193 * groups: NULL terminated list of groups to be removed
195 * If groups is not NULL, the all groups will be removed from the kobject
197 void sysfs_remove_groups(struct kobject *kobj,
198 const struct attribute_group **groups)
204 for (i = 0; groups[i]; i++)
205 sysfs_remove_group(kobj, groups[i]);
207 EXPORT_SYMBOL_GPL(sysfs_remove_groups);
210 * sysfs_merge_group - merge files into a pre-existing attribute group.
211 * @kobj: The kobject containing the group.
212 * @grp: The files to create and the attribute group they belong to.
214 * This function returns an error if the group doesn't exist or any of the
215 * files already exist in that group, in which case none of the new files
218 int sysfs_merge_group(struct kobject *kobj,
219 const struct attribute_group *grp)
221 struct sysfs_dirent *dir_sd;
223 struct attribute *const *attr;
226 dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name);
230 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
231 error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
234 sysfs_hash_and_remove(dir_sd, NULL, (*--attr)->name);
240 EXPORT_SYMBOL_GPL(sysfs_merge_group);
243 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
244 * @kobj: The kobject containing the group.
245 * @grp: The files to remove and the attribute group they belong to.
247 void sysfs_unmerge_group(struct kobject *kobj,
248 const struct attribute_group *grp)
250 struct sysfs_dirent *dir_sd;
251 struct attribute *const *attr;
253 dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name);
255 for (attr = grp->attrs; *attr; ++attr)
256 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
260 EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
263 * sysfs_add_link_to_group - add a symlink to an attribute group.
264 * @kobj: The kobject containing the group.
265 * @group_name: The name of the group.
266 * @target: The target kobject of the symlink to create.
267 * @link_name: The name of the symlink to create.
269 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
270 struct kobject *target, const char *link_name)
272 struct sysfs_dirent *dir_sd;
275 dir_sd = sysfs_get_dirent(kobj->sd, NULL, group_name);
279 error = sysfs_create_link_sd(dir_sd, target, link_name);
284 EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
287 * sysfs_remove_link_from_group - remove a symlink from an attribute group.
288 * @kobj: The kobject containing the group.
289 * @group_name: The name of the group.
290 * @link_name: The name of the symlink to remove.
292 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
293 const char *link_name)
295 struct sysfs_dirent *dir_sd;
297 dir_sd = sysfs_get_dirent(kobj->sd, NULL, group_name);
299 sysfs_hash_and_remove(dir_sd, NULL, link_name);
303 EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
305 EXPORT_SYMBOL_GPL(sysfs_create_group);
306 EXPORT_SYMBOL_GPL(sysfs_update_group);
307 EXPORT_SYMBOL_GPL(sysfs_remove_group);