Commit | Line | Data |
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1da177e4 LT |
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 | |
9e2a47ed GKH |
6 | * Copyright (c) 2013 Greg Kroah-Hartman |
7 | * Copyright (c) 2013 The Linux Foundation | |
1da177e4 | 8 | * |
e6c56920 | 9 | * This file is released undert the GPL v2. |
1da177e4 LT |
10 | * |
11 | */ | |
12 | ||
13 | #include <linux/kobject.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/dcache.h> | |
5f45f1a7 | 16 | #include <linux/namei.h> |
1da177e4 LT |
17 | #include <linux/err.h> |
18 | #include "sysfs.h" | |
19 | ||
20 | ||
324a56e1 | 21 | static void remove_files(struct kernfs_node *parent, struct kobject *kobj, |
608e266a | 22 | const struct attribute_group *grp) |
1da177e4 | 23 | { |
995d8ed9 GKH |
24 | struct attribute *const *attr; |
25 | struct bin_attribute *const *bin_attr; | |
1da177e4 | 26 | |
6ab9cea1 GKH |
27 | if (grp->attrs) |
28 | for (attr = grp->attrs; *attr; attr++) | |
324a56e1 | 29 | kernfs_remove_by_name(parent, (*attr)->name); |
6ab9cea1 GKH |
30 | if (grp->bin_attrs) |
31 | for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) | |
32 | sysfs_remove_bin_file(kobj, *bin_attr); | |
1da177e4 LT |
33 | } |
34 | ||
324a56e1 | 35 | static int create_files(struct kernfs_node *parent, struct kobject *kobj, |
0f423895 | 36 | const struct attribute_group *grp, int update) |
1da177e4 | 37 | { |
995d8ed9 GKH |
38 | struct attribute *const *attr; |
39 | struct bin_attribute *const *bin_attr; | |
d4acd722 | 40 | int error = 0, i; |
1da177e4 | 41 | |
6ab9cea1 GKH |
42 | if (grp->attrs) { |
43 | for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) { | |
44 | umode_t mode = 0; | |
0f423895 | 45 | |
6ab9cea1 GKH |
46 | /* |
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. | |
50 | */ | |
51 | if (update) | |
324a56e1 | 52 | kernfs_remove_by_name(parent, (*attr)->name); |
6ab9cea1 GKH |
53 | if (grp->is_visible) { |
54 | mode = grp->is_visible(kobj, *attr, i); | |
55 | if (!mode) | |
56 | continue; | |
57 | } | |
324a56e1 | 58 | error = sysfs_add_file_mode_ns(parent, *attr, false, |
58292cbe TH |
59 | (*attr)->mode | mode, |
60 | NULL); | |
6ab9cea1 GKH |
61 | if (unlikely(error)) |
62 | break; | |
63 | } | |
64 | if (error) { | |
324a56e1 | 65 | remove_files(parent, kobj, grp); |
6ab9cea1 GKH |
66 | goto exit; |
67 | } | |
68 | } | |
69 | ||
70 | if (grp->bin_attrs) { | |
71 | for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) { | |
72 | if (update) | |
73 | sysfs_remove_bin_file(kobj, *bin_attr); | |
74 | error = sysfs_create_bin_file(kobj, *bin_attr); | |
75 | if (error) | |
76 | break; | |
0f423895 | 77 | } |
6ab9cea1 | 78 | if (error) |
324a56e1 | 79 | remove_files(parent, kobj, grp); |
0f423895 | 80 | } |
6ab9cea1 | 81 | exit: |
1da177e4 LT |
82 | return error; |
83 | } | |
84 | ||
85 | ||
0f423895 JB |
86 | static int internal_create_group(struct kobject *kobj, int update, |
87 | const struct attribute_group *grp) | |
1da177e4 | 88 | { |
324a56e1 | 89 | struct kernfs_node *kn; |
1da177e4 LT |
90 | int error; |
91 | ||
0f423895 JB |
92 | BUG_ON(!kobj || (!update && !kobj->sd)); |
93 | ||
94 | /* Updates may happen before the object has been instantiated */ | |
95 | if (unlikely(update && !kobj->sd)) | |
96 | return -EINVAL; | |
388a8c35 OS |
97 | if (!grp->attrs && !grp->bin_attrs) { |
98 | WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n", | |
5631f2c1 BP |
99 | kobj->name, grp->name ? "" : grp->name); |
100 | return -EINVAL; | |
101 | } | |
1da177e4 | 102 | if (grp->name) { |
bb8b9d09 TH |
103 | kn = kernfs_create_dir(kobj->sd, grp->name, |
104 | S_IRWXU | S_IRUGO | S_IXUGO, kobj); | |
324a56e1 TH |
105 | if (IS_ERR(kn)) { |
106 | if (PTR_ERR(kn) == -EEXIST) | |
93b2b8e4 | 107 | sysfs_warn_dup(kobj->sd, grp->name); |
324a56e1 | 108 | return PTR_ERR(kn); |
93b2b8e4 | 109 | } |
1da177e4 | 110 | } else |
324a56e1 TH |
111 | kn = kobj->sd; |
112 | kernfs_get(kn); | |
113 | error = create_files(kn, kobj, grp, update); | |
608e266a | 114 | if (error) { |
1da177e4 | 115 | if (grp->name) |
324a56e1 | 116 | kernfs_remove(kn); |
1da177e4 | 117 | } |
324a56e1 | 118 | kernfs_put(kn); |
1da177e4 LT |
119 | return error; |
120 | } | |
121 | ||
0f423895 JB |
122 | /** |
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 | |
126 | * | |
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. | |
129 | * | |
130 | * Returns 0 on success or error. | |
131 | */ | |
132 | int sysfs_create_group(struct kobject *kobj, | |
133 | const struct attribute_group *grp) | |
134 | { | |
135 | return internal_create_group(kobj, 0, grp); | |
136 | } | |
d363bc53 | 137 | EXPORT_SYMBOL_GPL(sysfs_create_group); |
0f423895 | 138 | |
3e9b2bae GKH |
139 | /** |
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 | |
143 | * | |
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. | |
149 | * | |
09239ed4 | 150 | * Returns 0 on success or error code from sysfs_create_group on error. |
3e9b2bae GKH |
151 | */ |
152 | int sysfs_create_groups(struct kobject *kobj, | |
153 | const struct attribute_group **groups) | |
154 | { | |
155 | int error = 0; | |
156 | int i; | |
157 | ||
158 | if (!groups) | |
159 | return 0; | |
160 | ||
161 | for (i = 0; groups[i]; i++) { | |
162 | error = sysfs_create_group(kobj, groups[i]); | |
163 | if (error) { | |
164 | while (--i >= 0) | |
165 | sysfs_remove_group(kobj, groups[i]); | |
166 | break; | |
167 | } | |
168 | } | |
169 | return error; | |
170 | } | |
171 | EXPORT_SYMBOL_GPL(sysfs_create_groups); | |
172 | ||
0f423895 | 173 | /** |
1f8e1cda RD |
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 | |
0f423895 JB |
177 | * |
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 | |
183 | * relevant files. | |
184 | * | |
185 | * The primary use for this function is to call it after making a change | |
186 | * that affects group visibility. | |
187 | * | |
188 | * Returns 0 on success or error. | |
189 | */ | |
190 | int sysfs_update_group(struct kobject *kobj, | |
191 | const struct attribute_group *grp) | |
192 | { | |
193 | return internal_create_group(kobj, 1, grp); | |
194 | } | |
d363bc53 | 195 | EXPORT_SYMBOL_GPL(sysfs_update_group); |
0f423895 | 196 | |
f9ae443b GKH |
197 | /** |
198 | * sysfs_remove_group: remove a group from a kobject | |
199 | * @kobj: kobject to remove the group from | |
200 | * @grp: group to remove | |
201 | * | |
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. | |
204 | */ | |
995d8ed9 GKH |
205 | void sysfs_remove_group(struct kobject *kobj, |
206 | const struct attribute_group *grp) | |
1da177e4 | 207 | { |
324a56e1 TH |
208 | struct kernfs_node *parent = kobj->sd; |
209 | struct kernfs_node *kn; | |
1da177e4 | 210 | |
057f6c01 | 211 | if (grp->name) { |
324a56e1 TH |
212 | kn = kernfs_find_and_get(parent, grp->name); |
213 | if (!kn) { | |
214 | WARN(!kn, KERN_WARNING | |
16aebf1c GKH |
215 | "sysfs group %p not found for kobject '%s'\n", |
216 | grp, kobject_name(kobj)); | |
969affd2 GKH |
217 | return; |
218 | } | |
ccf73cf3 | 219 | } else { |
324a56e1 TH |
220 | kn = parent; |
221 | kernfs_get(kn); | |
ccf73cf3 | 222 | } |
1da177e4 | 223 | |
324a56e1 | 224 | remove_files(kn, kobj, grp); |
1da177e4 | 225 | if (grp->name) |
324a56e1 | 226 | kernfs_remove(kn); |
608e266a | 227 | |
324a56e1 | 228 | kernfs_put(kn); |
1da177e4 | 229 | } |
d363bc53 | 230 | EXPORT_SYMBOL_GPL(sysfs_remove_group); |
1da177e4 | 231 | |
3e9b2bae GKH |
232 | /** |
233 | * sysfs_remove_groups - remove a list of groups | |
234 | * | |
f9ae443b GKH |
235 | * @kobj: The kobject for the groups to be removed from |
236 | * @groups: NULL terminated list of groups to be removed | |
3e9b2bae | 237 | * |
09239ed4 | 238 | * If groups is not NULL, remove the specified groups from the kobject. |
3e9b2bae GKH |
239 | */ |
240 | void sysfs_remove_groups(struct kobject *kobj, | |
241 | const struct attribute_group **groups) | |
242 | { | |
243 | int i; | |
244 | ||
245 | if (!groups) | |
246 | return; | |
247 | for (i = 0; groups[i]; i++) | |
248 | sysfs_remove_group(kobj, groups[i]); | |
249 | } | |
250 | EXPORT_SYMBOL_GPL(sysfs_remove_groups); | |
251 | ||
69d44ffb AS |
252 | /** |
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. | |
256 | * | |
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 | |
259 | * are created. | |
260 | */ | |
261 | int sysfs_merge_group(struct kobject *kobj, | |
262 | const struct attribute_group *grp) | |
263 | { | |
324a56e1 | 264 | struct kernfs_node *parent; |
69d44ffb AS |
265 | int error = 0; |
266 | struct attribute *const *attr; | |
267 | int i; | |
268 | ||
324a56e1 TH |
269 | parent = kernfs_find_and_get(kobj->sd, grp->name); |
270 | if (!parent) | |
69d44ffb AS |
271 | return -ENOENT; |
272 | ||
273 | for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr)) | |
324a56e1 | 274 | error = sysfs_add_file(parent, *attr, false); |
69d44ffb AS |
275 | if (error) { |
276 | while (--i >= 0) | |
324a56e1 | 277 | kernfs_remove_by_name(parent, (*--attr)->name); |
69d44ffb | 278 | } |
324a56e1 | 279 | kernfs_put(parent); |
69d44ffb AS |
280 | |
281 | return error; | |
282 | } | |
283 | EXPORT_SYMBOL_GPL(sysfs_merge_group); | |
284 | ||
285 | /** | |
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. | |
289 | */ | |
290 | void sysfs_unmerge_group(struct kobject *kobj, | |
291 | const struct attribute_group *grp) | |
292 | { | |
324a56e1 | 293 | struct kernfs_node *parent; |
69d44ffb AS |
294 | struct attribute *const *attr; |
295 | ||
324a56e1 TH |
296 | parent = kernfs_find_and_get(kobj->sd, grp->name); |
297 | if (parent) { | |
69d44ffb | 298 | for (attr = grp->attrs; *attr; ++attr) |
324a56e1 TH |
299 | kernfs_remove_by_name(parent, (*attr)->name); |
300 | kernfs_put(parent); | |
69d44ffb AS |
301 | } |
302 | } | |
303 | EXPORT_SYMBOL_GPL(sysfs_unmerge_group); | |
304 | ||
0bb8f3d6 RW |
305 | /** |
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. | |
311 | */ | |
312 | int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name, | |
313 | struct kobject *target, const char *link_name) | |
314 | { | |
324a56e1 | 315 | struct kernfs_node *parent; |
0bb8f3d6 RW |
316 | int error = 0; |
317 | ||
324a56e1 TH |
318 | parent = kernfs_find_and_get(kobj->sd, group_name); |
319 | if (!parent) | |
0bb8f3d6 RW |
320 | return -ENOENT; |
321 | ||
324a56e1 TH |
322 | error = sysfs_create_link_sd(parent, target, link_name); |
323 | kernfs_put(parent); | |
0bb8f3d6 RW |
324 | |
325 | return error; | |
326 | } | |
327 | EXPORT_SYMBOL_GPL(sysfs_add_link_to_group); | |
328 | ||
329 | /** | |
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. | |
334 | */ | |
335 | void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, | |
336 | const char *link_name) | |
337 | { | |
324a56e1 | 338 | struct kernfs_node *parent; |
0bb8f3d6 | 339 | |
324a56e1 TH |
340 | parent = kernfs_find_and_get(kobj->sd, group_name); |
341 | if (parent) { | |
342 | kernfs_remove_by_name(parent, link_name); | |
343 | kernfs_put(parent); | |
0bb8f3d6 RW |
344 | } |
345 | } | |
346 | EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group); |