Loading...
1/*
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
6 *
7 * This file is released undert the GPL v2.
8 *
9 */
10
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>
16#include "sysfs.h"
17
18
19static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
20 const struct attribute_group *grp)
21{
22 struct attribute *const* attr;
23 int i;
24
25 for (i = 0, attr = grp->attrs; *attr; i++, attr++)
26 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
27}
28
29static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
30 const struct attribute_group *grp, int update)
31{
32 struct attribute *const* attr;
33 int error = 0, i;
34
35 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
36 mode_t mode = 0;
37
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 */
41 if (update)
42 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
43 if (grp->is_visible) {
44 mode = grp->is_visible(kobj, *attr, i);
45 if (!mode)
46 continue;
47 }
48 error = sysfs_add_file_mode(dir_sd, *attr, SYSFS_KOBJ_ATTR,
49 (*attr)->mode | mode);
50 if (unlikely(error))
51 break;
52 }
53 if (error)
54 remove_files(dir_sd, kobj, grp);
55 return error;
56}
57
58
59static int internal_create_group(struct kobject *kobj, int update,
60 const struct attribute_group *grp)
61{
62 struct sysfs_dirent *sd;
63 int error;
64
65 BUG_ON(!kobj || (!update && !kobj->sd));
66
67 /* Updates may happen before the object has been instantiated */
68 if (unlikely(update && !kobj->sd))
69 return -EINVAL;
70
71 if (grp->name) {
72 error = sysfs_create_subdir(kobj, grp->name, &sd);
73 if (error)
74 return error;
75 } else
76 sd = kobj->sd;
77 sysfs_get(sd);
78 error = create_files(sd, kobj, grp, update);
79 if (error) {
80 if (grp->name)
81 sysfs_remove_subdir(sd);
82 }
83 sysfs_put(sd);
84 return error;
85}
86
87/**
88 * sysfs_create_group - given a directory kobject, create an attribute group
89 * @kobj: The kobject to create the group on
90 * @grp: The attribute group to create
91 *
92 * This function creates a group for the first time. It will explicitly
93 * warn and error if any of the attribute files being created already exist.
94 *
95 * Returns 0 on success or error.
96 */
97int sysfs_create_group(struct kobject *kobj,
98 const struct attribute_group *grp)
99{
100 return internal_create_group(kobj, 0, grp);
101}
102
103/**
104 * sysfs_update_group - given a directory kobject, update an attribute group
105 * @kobj: The kobject to update the group on
106 * @grp: The attribute group to update
107 *
108 * This function updates an attribute group. Unlike
109 * sysfs_create_group(), it will explicitly not warn or error if any
110 * of the attribute files being created already exist. Furthermore,
111 * if the visibility of the files has changed through the is_visible()
112 * callback, it will update the permissions and add or remove the
113 * relevant files.
114 *
115 * The primary use for this function is to call it after making a change
116 * that affects group visibility.
117 *
118 * Returns 0 on success or error.
119 */
120int sysfs_update_group(struct kobject *kobj,
121 const struct attribute_group *grp)
122{
123 return internal_create_group(kobj, 1, grp);
124}
125
126
127
128void sysfs_remove_group(struct kobject * kobj,
129 const struct attribute_group * grp)
130{
131 struct sysfs_dirent *dir_sd = kobj->sd;
132 struct sysfs_dirent *sd;
133
134 if (grp->name) {
135 sd = sysfs_get_dirent(dir_sd, NULL, grp->name);
136 if (!sd) {
137 WARN(!sd, KERN_WARNING "sysfs group %p not found for "
138 "kobject '%s'\n", grp, kobject_name(kobj));
139 return;
140 }
141 } else
142 sd = sysfs_get(dir_sd);
143
144 remove_files(sd, kobj, grp);
145 if (grp->name)
146 sysfs_remove_subdir(sd);
147
148 sysfs_put(sd);
149}
150
151/**
152 * sysfs_merge_group - merge files into a pre-existing attribute group.
153 * @kobj: The kobject containing the group.
154 * @grp: The files to create and the attribute group they belong to.
155 *
156 * This function returns an error if the group doesn't exist or any of the
157 * files already exist in that group, in which case none of the new files
158 * are created.
159 */
160int sysfs_merge_group(struct kobject *kobj,
161 const struct attribute_group *grp)
162{
163 struct sysfs_dirent *dir_sd;
164 int error = 0;
165 struct attribute *const *attr;
166 int i;
167
168 dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name);
169 if (!dir_sd)
170 return -ENOENT;
171
172 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
173 error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
174 if (error) {
175 while (--i >= 0)
176 sysfs_hash_and_remove(dir_sd, NULL, (*--attr)->name);
177 }
178 sysfs_put(dir_sd);
179
180 return error;
181}
182EXPORT_SYMBOL_GPL(sysfs_merge_group);
183
184/**
185 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
186 * @kobj: The kobject containing the group.
187 * @grp: The files to remove and the attribute group they belong to.
188 */
189void sysfs_unmerge_group(struct kobject *kobj,
190 const struct attribute_group *grp)
191{
192 struct sysfs_dirent *dir_sd;
193 struct attribute *const *attr;
194
195 dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name);
196 if (dir_sd) {
197 for (attr = grp->attrs; *attr; ++attr)
198 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
199 sysfs_put(dir_sd);
200 }
201}
202EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
203
204
205EXPORT_SYMBOL_GPL(sysfs_create_group);
206EXPORT_SYMBOL_GPL(sysfs_update_group);
207EXPORT_SYMBOL_GPL(sysfs_remove_group);
1/*
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
6 *
7 * This file is released undert the GPL v2.
8 *
9 */
10
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>
16#include "sysfs.h"
17
18
19static void remove_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
20 const struct attribute_group *grp)
21{
22 struct attribute *const* attr;
23 int i;
24
25 for (i = 0, attr = grp->attrs; *attr; i++, attr++)
26 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
27}
28
29static int create_files(struct sysfs_dirent *dir_sd, struct kobject *kobj,
30 const struct attribute_group *grp, int update)
31{
32 struct attribute *const* attr;
33 int error = 0, i;
34
35 for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
36 umode_t mode = 0;
37
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 */
41 if (update)
42 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
43 if (grp->is_visible) {
44 mode = grp->is_visible(kobj, *attr, i);
45 if (!mode)
46 continue;
47 }
48 error = sysfs_add_file_mode(dir_sd, *attr, SYSFS_KOBJ_ATTR,
49 (*attr)->mode | mode);
50 if (unlikely(error))
51 break;
52 }
53 if (error)
54 remove_files(dir_sd, kobj, grp);
55 return error;
56}
57
58
59static int internal_create_group(struct kobject *kobj, int update,
60 const struct attribute_group *grp)
61{
62 struct sysfs_dirent *sd;
63 int error;
64
65 BUG_ON(!kobj || (!update && !kobj->sd));
66
67 /* Updates may happen before the object has been instantiated */
68 if (unlikely(update && !kobj->sd))
69 return -EINVAL;
70 if (!grp->attrs) {
71 WARN(1, "sysfs: attrs not set by subsystem for group: %s/%s\n",
72 kobj->name, grp->name ? "" : grp->name);
73 return -EINVAL;
74 }
75 if (grp->name) {
76 error = sysfs_create_subdir(kobj, grp->name, &sd);
77 if (error)
78 return error;
79 } else
80 sd = kobj->sd;
81 sysfs_get(sd);
82 error = create_files(sd, kobj, grp, update);
83 if (error) {
84 if (grp->name)
85 sysfs_remove_subdir(sd);
86 }
87 sysfs_put(sd);
88 return error;
89}
90
91/**
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
95 *
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.
98 *
99 * Returns 0 on success or error.
100 */
101int sysfs_create_group(struct kobject *kobj,
102 const struct attribute_group *grp)
103{
104 return internal_create_group(kobj, 0, grp);
105}
106
107/**
108 * sysfs_update_group - given a directory kobject, update an attribute group
109 * @kobj: The kobject to update the group on
110 * @grp: The attribute group to update
111 *
112 * This function updates an attribute group. Unlike
113 * sysfs_create_group(), it will explicitly not warn or error if any
114 * of the attribute files being created already exist. Furthermore,
115 * if the visibility of the files has changed through the is_visible()
116 * callback, it will update the permissions and add or remove the
117 * relevant files.
118 *
119 * The primary use for this function is to call it after making a change
120 * that affects group visibility.
121 *
122 * Returns 0 on success or error.
123 */
124int sysfs_update_group(struct kobject *kobj,
125 const struct attribute_group *grp)
126{
127 return internal_create_group(kobj, 1, grp);
128}
129
130
131
132void sysfs_remove_group(struct kobject * kobj,
133 const struct attribute_group * grp)
134{
135 struct sysfs_dirent *dir_sd = kobj->sd;
136 struct sysfs_dirent *sd;
137
138 if (grp->name) {
139 sd = sysfs_get_dirent(dir_sd, NULL, grp->name);
140 if (!sd) {
141 WARN(!sd, KERN_WARNING "sysfs group %p not found for "
142 "kobject '%s'\n", grp, kobject_name(kobj));
143 return;
144 }
145 } else
146 sd = sysfs_get(dir_sd);
147
148 remove_files(sd, kobj, grp);
149 if (grp->name)
150 sysfs_remove_subdir(sd);
151
152 sysfs_put(sd);
153}
154
155/**
156 * sysfs_merge_group - merge files into a pre-existing attribute group.
157 * @kobj: The kobject containing the group.
158 * @grp: The files to create and the attribute group they belong to.
159 *
160 * This function returns an error if the group doesn't exist or any of the
161 * files already exist in that group, in which case none of the new files
162 * are created.
163 */
164int sysfs_merge_group(struct kobject *kobj,
165 const struct attribute_group *grp)
166{
167 struct sysfs_dirent *dir_sd;
168 int error = 0;
169 struct attribute *const *attr;
170 int i;
171
172 dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name);
173 if (!dir_sd)
174 return -ENOENT;
175
176 for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
177 error = sysfs_add_file(dir_sd, *attr, SYSFS_KOBJ_ATTR);
178 if (error) {
179 while (--i >= 0)
180 sysfs_hash_and_remove(dir_sd, NULL, (*--attr)->name);
181 }
182 sysfs_put(dir_sd);
183
184 return error;
185}
186EXPORT_SYMBOL_GPL(sysfs_merge_group);
187
188/**
189 * sysfs_unmerge_group - remove files from a pre-existing attribute group.
190 * @kobj: The kobject containing the group.
191 * @grp: The files to remove and the attribute group they belong to.
192 */
193void sysfs_unmerge_group(struct kobject *kobj,
194 const struct attribute_group *grp)
195{
196 struct sysfs_dirent *dir_sd;
197 struct attribute *const *attr;
198
199 dir_sd = sysfs_get_dirent(kobj->sd, NULL, grp->name);
200 if (dir_sd) {
201 for (attr = grp->attrs; *attr; ++attr)
202 sysfs_hash_and_remove(dir_sd, NULL, (*attr)->name);
203 sysfs_put(dir_sd);
204 }
205}
206EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
207
208
209EXPORT_SYMBOL_GPL(sysfs_create_group);
210EXPORT_SYMBOL_GPL(sysfs_update_group);
211EXPORT_SYMBOL_GPL(sysfs_remove_group);