Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * dir.c - Operations for sysfs directories. | |
3 | */ | |
4 | ||
5 | #undef DEBUG | |
6 | ||
7 | #include <linux/fs.h> | |
8 | #include <linux/mount.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/kobject.h> | |
5f45f1a7 | 11 | #include <linux/namei.h> |
1da177e4 LT |
12 | #include "sysfs.h" |
13 | ||
14 | DECLARE_RWSEM(sysfs_rename_sem); | |
15 | ||
16 | static void sysfs_d_iput(struct dentry * dentry, struct inode * inode) | |
17 | { | |
18 | struct sysfs_dirent * sd = dentry->d_fsdata; | |
19 | ||
20 | if (sd) { | |
21 | BUG_ON(sd->s_dentry != dentry); | |
22 | sd->s_dentry = NULL; | |
23 | sysfs_put(sd); | |
24 | } | |
25 | iput(inode); | |
26 | } | |
27 | ||
28 | static struct dentry_operations sysfs_dentry_ops = { | |
29 | .d_iput = sysfs_d_iput, | |
30 | }; | |
31 | ||
32 | /* | |
33 | * Allocates a new sysfs_dirent and links it to the parent sysfs_dirent | |
34 | */ | |
35 | static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd, | |
36 | void * element) | |
37 | { | |
38 | struct sysfs_dirent * sd; | |
39 | ||
40 | sd = kmem_cache_alloc(sysfs_dir_cachep, GFP_KERNEL); | |
41 | if (!sd) | |
42 | return NULL; | |
43 | ||
44 | memset(sd, 0, sizeof(*sd)); | |
45 | atomic_set(&sd->s_count, 1); | |
46 | INIT_LIST_HEAD(&sd->s_children); | |
47 | list_add(&sd->s_sibling, &parent_sd->s_children); | |
48 | sd->s_element = element; | |
49 | ||
50 | return sd; | |
51 | } | |
52 | ||
c516865c MS |
53 | /** |
54 | * | |
55 | * Return -EEXIST if there is already a sysfs element with the same name for | |
56 | * the same parent. | |
57 | * | |
58 | * called with parent inode's i_mutex held | |
59 | */ | |
60 | int sysfs_dirent_exist(struct sysfs_dirent *parent_sd, | |
61 | const unsigned char *new) | |
62 | { | |
63 | struct sysfs_dirent * sd; | |
64 | ||
65 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
66 | if (sd->s_element) { | |
67 | const unsigned char *existing = sysfs_get_name(sd); | |
68 | if (strcmp(existing, new)) | |
69 | continue; | |
70 | else | |
71 | return -EEXIST; | |
72 | } | |
73 | } | |
74 | ||
75 | return 0; | |
76 | } | |
77 | ||
78 | ||
1da177e4 LT |
79 | int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry, |
80 | void * element, umode_t mode, int type) | |
81 | { | |
82 | struct sysfs_dirent * sd; | |
83 | ||
84 | sd = sysfs_new_dirent(parent_sd, element); | |
85 | if (!sd) | |
86 | return -ENOMEM; | |
87 | ||
88 | sd->s_mode = mode; | |
89 | sd->s_type = type; | |
90 | sd->s_dentry = dentry; | |
91 | if (dentry) { | |
92 | dentry->d_fsdata = sysfs_get(sd); | |
93 | dentry->d_op = &sysfs_dentry_ops; | |
94 | } | |
95 | ||
96 | return 0; | |
97 | } | |
98 | ||
99 | static int init_dir(struct inode * inode) | |
100 | { | |
101 | inode->i_op = &sysfs_dir_inode_operations; | |
102 | inode->i_fop = &sysfs_dir_operations; | |
103 | ||
104 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
105 | inode->i_nlink++; | |
106 | return 0; | |
107 | } | |
108 | ||
109 | static int init_file(struct inode * inode) | |
110 | { | |
111 | inode->i_size = PAGE_SIZE; | |
112 | inode->i_fop = &sysfs_file_operations; | |
113 | return 0; | |
114 | } | |
115 | ||
116 | static int init_symlink(struct inode * inode) | |
117 | { | |
118 | inode->i_op = &sysfs_symlink_inode_operations; | |
119 | return 0; | |
120 | } | |
121 | ||
122 | static int create_dir(struct kobject * k, struct dentry * p, | |
123 | const char * n, struct dentry ** d) | |
124 | { | |
125 | int error; | |
126 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; | |
127 | ||
1b1dcc1b | 128 | mutex_lock(&p->d_inode->i_mutex); |
5f45f1a7 | 129 | *d = lookup_one_len(n, p, strlen(n)); |
1da177e4 | 130 | if (!IS_ERR(*d)) { |
c516865c MS |
131 | if (sysfs_dirent_exist(p->d_fsdata, n)) |
132 | error = -EEXIST; | |
133 | else | |
134 | error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, | |
135 | SYSFS_DIR); | |
1da177e4 | 136 | if (!error) { |
6fa5c828 | 137 | error = sysfs_create(*d, mode, init_dir); |
1da177e4 LT |
138 | if (!error) { |
139 | p->d_inode->i_nlink++; | |
140 | (*d)->d_op = &sysfs_dentry_ops; | |
141 | d_rehash(*d); | |
142 | } | |
143 | } | |
6fa5c828 | 144 | if (error && (error != -EEXIST)) { |
e80a5dea SR |
145 | struct sysfs_dirent *sd = (*d)->d_fsdata; |
146 | if (sd) { | |
147 | list_del_init(&sd->s_sibling); | |
148 | sysfs_put(sd); | |
149 | } | |
1da177e4 | 150 | d_drop(*d); |
6fa5c828 | 151 | } |
1da177e4 LT |
152 | dput(*d); |
153 | } else | |
154 | error = PTR_ERR(*d); | |
1b1dcc1b | 155 | mutex_unlock(&p->d_inode->i_mutex); |
1da177e4 LT |
156 | return error; |
157 | } | |
158 | ||
159 | ||
160 | int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d) | |
161 | { | |
162 | return create_dir(k,k->dentry,n,d); | |
163 | } | |
164 | ||
165 | /** | |
166 | * sysfs_create_dir - create a directory for an object. | |
167 | * @parent: parent parent object. | |
168 | * @kobj: object we're creating directory for. | |
169 | */ | |
170 | ||
171 | int sysfs_create_dir(struct kobject * kobj) | |
172 | { | |
173 | struct dentry * dentry = NULL; | |
174 | struct dentry * parent; | |
175 | int error = 0; | |
176 | ||
177 | BUG_ON(!kobj); | |
178 | ||
179 | if (kobj->parent) | |
180 | parent = kobj->parent->dentry; | |
181 | else if (sysfs_mount && sysfs_mount->mnt_sb) | |
182 | parent = sysfs_mount->mnt_sb->s_root; | |
183 | else | |
184 | return -EFAULT; | |
185 | ||
186 | error = create_dir(kobj,parent,kobject_name(kobj),&dentry); | |
187 | if (!error) | |
188 | kobj->dentry = dentry; | |
189 | return error; | |
190 | } | |
191 | ||
192 | /* attaches attribute's sysfs_dirent to the dentry corresponding to the | |
193 | * attribute file | |
194 | */ | |
195 | static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry) | |
196 | { | |
197 | struct attribute * attr = NULL; | |
198 | struct bin_attribute * bin_attr = NULL; | |
199 | int (* init) (struct inode *) = NULL; | |
200 | int error = 0; | |
201 | ||
202 | if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) { | |
203 | bin_attr = sd->s_element; | |
204 | attr = &bin_attr->attr; | |
205 | } else { | |
206 | attr = sd->s_element; | |
207 | init = init_file; | |
208 | } | |
209 | ||
6fa5c828 MS |
210 | dentry->d_fsdata = sysfs_get(sd); |
211 | sd->s_dentry = dentry; | |
1da177e4 | 212 | error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init); |
6fa5c828 MS |
213 | if (error) { |
214 | sysfs_put(sd); | |
1da177e4 | 215 | return error; |
6fa5c828 | 216 | } |
1da177e4 LT |
217 | |
218 | if (bin_attr) { | |
219 | dentry->d_inode->i_size = bin_attr->size; | |
220 | dentry->d_inode->i_fop = &bin_fops; | |
221 | } | |
222 | dentry->d_op = &sysfs_dentry_ops; | |
1da177e4 LT |
223 | d_rehash(dentry); |
224 | ||
225 | return 0; | |
226 | } | |
227 | ||
228 | static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry) | |
229 | { | |
230 | int err = 0; | |
231 | ||
6fa5c828 MS |
232 | dentry->d_fsdata = sysfs_get(sd); |
233 | sd->s_dentry = dentry; | |
1da177e4 LT |
234 | err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink); |
235 | if (!err) { | |
236 | dentry->d_op = &sysfs_dentry_ops; | |
1da177e4 | 237 | d_rehash(dentry); |
6fa5c828 MS |
238 | } else |
239 | sysfs_put(sd); | |
240 | ||
1da177e4 LT |
241 | return err; |
242 | } | |
243 | ||
244 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, | |
245 | struct nameidata *nd) | |
246 | { | |
247 | struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata; | |
248 | struct sysfs_dirent * sd; | |
249 | int err = 0; | |
250 | ||
251 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
252 | if (sd->s_type & SYSFS_NOT_PINNED) { | |
253 | const unsigned char * name = sysfs_get_name(sd); | |
254 | ||
255 | if (strcmp(name, dentry->d_name.name)) | |
256 | continue; | |
257 | ||
258 | if (sd->s_type & SYSFS_KOBJ_LINK) | |
259 | err = sysfs_attach_link(sd, dentry); | |
260 | else | |
261 | err = sysfs_attach_attr(sd, dentry); | |
262 | break; | |
263 | } | |
264 | } | |
265 | ||
266 | return ERR_PTR(err); | |
267 | } | |
268 | ||
269 | struct inode_operations sysfs_dir_inode_operations = { | |
270 | .lookup = sysfs_lookup, | |
988d186d | 271 | .setattr = sysfs_setattr, |
1da177e4 LT |
272 | }; |
273 | ||
274 | static void remove_dir(struct dentry * d) | |
275 | { | |
276 | struct dentry * parent = dget(d->d_parent); | |
277 | struct sysfs_dirent * sd; | |
278 | ||
1b1dcc1b | 279 | mutex_lock(&parent->d_inode->i_mutex); |
1da177e4 LT |
280 | d_delete(d); |
281 | sd = d->d_fsdata; | |
282 | list_del_init(&sd->s_sibling); | |
283 | sysfs_put(sd); | |
284 | if (d->d_inode) | |
285 | simple_rmdir(parent->d_inode,d); | |
286 | ||
287 | pr_debug(" o %s removing done (%d)\n",d->d_name.name, | |
288 | atomic_read(&d->d_count)); | |
289 | ||
1b1dcc1b | 290 | mutex_unlock(&parent->d_inode->i_mutex); |
1da177e4 LT |
291 | dput(parent); |
292 | } | |
293 | ||
294 | void sysfs_remove_subdir(struct dentry * d) | |
295 | { | |
296 | remove_dir(d); | |
297 | } | |
298 | ||
299 | ||
300 | /** | |
301 | * sysfs_remove_dir - remove an object's directory. | |
302 | * @kobj: object. | |
303 | * | |
304 | * The only thing special about this is that we remove any files in | |
305 | * the directory before we remove the directory, and we've inlined | |
306 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
307 | */ | |
308 | ||
309 | void sysfs_remove_dir(struct kobject * kobj) | |
310 | { | |
311 | struct dentry * dentry = dget(kobj->dentry); | |
312 | struct sysfs_dirent * parent_sd; | |
313 | struct sysfs_dirent * sd, * tmp; | |
314 | ||
315 | if (!dentry) | |
316 | return; | |
317 | ||
318 | pr_debug("sysfs %s: removing dir\n",dentry->d_name.name); | |
1b1dcc1b | 319 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
320 | parent_sd = dentry->d_fsdata; |
321 | list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { | |
322 | if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED)) | |
323 | continue; | |
324 | list_del_init(&sd->s_sibling); | |
325 | sysfs_drop_dentry(sd, dentry); | |
326 | sysfs_put(sd); | |
327 | } | |
1b1dcc1b | 328 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
329 | |
330 | remove_dir(dentry); | |
331 | /** | |
332 | * Drop reference from dget() on entrance. | |
333 | */ | |
334 | dput(dentry); | |
641e6f30 | 335 | kobj->dentry = NULL; |
1da177e4 LT |
336 | } |
337 | ||
338 | int sysfs_rename_dir(struct kobject * kobj, const char *new_name) | |
339 | { | |
340 | int error = 0; | |
341 | struct dentry * new_dentry, * parent; | |
342 | ||
343 | if (!strcmp(kobject_name(kobj), new_name)) | |
344 | return -EINVAL; | |
345 | ||
346 | if (!kobj->parent) | |
347 | return -EINVAL; | |
348 | ||
349 | down_write(&sysfs_rename_sem); | |
350 | parent = kobj->parent->dentry; | |
351 | ||
1b1dcc1b | 352 | mutex_lock(&parent->d_inode->i_mutex); |
1da177e4 | 353 | |
5f45f1a7 | 354 | new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); |
1da177e4 LT |
355 | if (!IS_ERR(new_dentry)) { |
356 | if (!new_dentry->d_inode) { | |
357 | error = kobject_set_name(kobj, "%s", new_name); | |
358 | if (!error) { | |
359 | d_add(new_dentry, NULL); | |
360 | d_move(kobj->dentry, new_dentry); | |
361 | } | |
362 | else | |
363 | d_drop(new_dentry); | |
364 | } else | |
365 | error = -EEXIST; | |
366 | dput(new_dentry); | |
367 | } | |
1b1dcc1b | 368 | mutex_unlock(&parent->d_inode->i_mutex); |
1da177e4 LT |
369 | up_write(&sysfs_rename_sem); |
370 | ||
371 | return error; | |
372 | } | |
373 | ||
374 | static int sysfs_dir_open(struct inode *inode, struct file *file) | |
375 | { | |
376 | struct dentry * dentry = file->f_dentry; | |
377 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; | |
378 | ||
1b1dcc1b | 379 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 380 | file->private_data = sysfs_new_dirent(parent_sd, NULL); |
1b1dcc1b | 381 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
382 | |
383 | return file->private_data ? 0 : -ENOMEM; | |
384 | ||
385 | } | |
386 | ||
387 | static int sysfs_dir_close(struct inode *inode, struct file *file) | |
388 | { | |
389 | struct dentry * dentry = file->f_dentry; | |
390 | struct sysfs_dirent * cursor = file->private_data; | |
391 | ||
1b1dcc1b | 392 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 393 | list_del_init(&cursor->s_sibling); |
1b1dcc1b | 394 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
395 | |
396 | release_sysfs_dirent(cursor); | |
397 | ||
398 | return 0; | |
399 | } | |
400 | ||
401 | /* Relationship between s_mode and the DT_xxx types */ | |
402 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
403 | { | |
404 | return (sd->s_mode >> 12) & 15; | |
405 | } | |
406 | ||
407 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
408 | { | |
409 | struct dentry *dentry = filp->f_dentry; | |
410 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; | |
411 | struct sysfs_dirent *cursor = filp->private_data; | |
412 | struct list_head *p, *q = &cursor->s_sibling; | |
413 | ino_t ino; | |
414 | int i = filp->f_pos; | |
415 | ||
416 | switch (i) { | |
417 | case 0: | |
418 | ino = dentry->d_inode->i_ino; | |
419 | if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) | |
420 | break; | |
421 | filp->f_pos++; | |
422 | i++; | |
423 | /* fallthrough */ | |
424 | case 1: | |
425 | ino = parent_ino(dentry); | |
426 | if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) | |
427 | break; | |
428 | filp->f_pos++; | |
429 | i++; | |
430 | /* fallthrough */ | |
431 | default: | |
432 | if (filp->f_pos == 2) { | |
433 | list_del(q); | |
434 | list_add(q, &parent_sd->s_children); | |
435 | } | |
436 | for (p=q->next; p!= &parent_sd->s_children; p=p->next) { | |
437 | struct sysfs_dirent *next; | |
438 | const char * name; | |
439 | int len; | |
440 | ||
441 | next = list_entry(p, struct sysfs_dirent, | |
442 | s_sibling); | |
443 | if (!next->s_element) | |
444 | continue; | |
445 | ||
446 | name = sysfs_get_name(next); | |
447 | len = strlen(name); | |
448 | if (next->s_dentry) | |
449 | ino = next->s_dentry->d_inode->i_ino; | |
450 | else | |
451 | ino = iunique(sysfs_sb, 2); | |
452 | ||
453 | if (filldir(dirent, name, len, filp->f_pos, ino, | |
454 | dt_type(next)) < 0) | |
455 | return 0; | |
456 | ||
457 | list_del(q); | |
458 | list_add(q, p); | |
459 | p = q; | |
460 | filp->f_pos++; | |
461 | } | |
462 | } | |
463 | return 0; | |
464 | } | |
465 | ||
466 | static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) | |
467 | { | |
468 | struct dentry * dentry = file->f_dentry; | |
469 | ||
1b1dcc1b | 470 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
471 | switch (origin) { |
472 | case 1: | |
473 | offset += file->f_pos; | |
474 | case 0: | |
475 | if (offset >= 0) | |
476 | break; | |
477 | default: | |
1b1dcc1b | 478 | mutex_unlock(&file->f_dentry->d_inode->i_mutex); |
1da177e4 LT |
479 | return -EINVAL; |
480 | } | |
481 | if (offset != file->f_pos) { | |
482 | file->f_pos = offset; | |
483 | if (file->f_pos >= 2) { | |
484 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
485 | struct sysfs_dirent *cursor = file->private_data; | |
486 | struct list_head *p; | |
487 | loff_t n = file->f_pos - 2; | |
488 | ||
489 | list_del(&cursor->s_sibling); | |
490 | p = sd->s_children.next; | |
491 | while (n && p != &sd->s_children) { | |
492 | struct sysfs_dirent *next; | |
493 | next = list_entry(p, struct sysfs_dirent, | |
494 | s_sibling); | |
495 | if (next->s_element) | |
496 | n--; | |
497 | p = p->next; | |
498 | } | |
499 | list_add_tail(&cursor->s_sibling, p); | |
500 | } | |
501 | } | |
1b1dcc1b | 502 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
503 | return offset; |
504 | } | |
505 | ||
4b6f5d20 | 506 | const struct file_operations sysfs_dir_operations = { |
1da177e4 LT |
507 | .open = sysfs_dir_open, |
508 | .release = sysfs_dir_close, | |
509 | .llseek = sysfs_dir_lseek, | |
510 | .read = generic_read_dir, | |
511 | .readdir = sysfs_readdir, | |
512 | }; |