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Commit | Line | Data |
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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); | |
eea3f891 | 46 | atomic_set(&sd->s_event, 1); |
1da177e4 LT |
47 | INIT_LIST_HEAD(&sd->s_children); |
48 | list_add(&sd->s_sibling, &parent_sd->s_children); | |
49 | sd->s_element = element; | |
50 | ||
51 | return sd; | |
52 | } | |
53 | ||
a580290c | 54 | /* |
c516865c MS |
55 | * |
56 | * Return -EEXIST if there is already a sysfs element with the same name for | |
57 | * the same parent. | |
58 | * | |
59 | * called with parent inode's i_mutex held | |
60 | */ | |
61 | int sysfs_dirent_exist(struct sysfs_dirent *parent_sd, | |
62 | const unsigned char *new) | |
63 | { | |
64 | struct sysfs_dirent * sd; | |
65 | ||
66 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
67 | if (sd->s_element) { | |
68 | const unsigned char *existing = sysfs_get_name(sd); | |
69 | if (strcmp(existing, new)) | |
70 | continue; | |
71 | else | |
72 | return -EEXIST; | |
73 | } | |
74 | } | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | ||
1da177e4 LT |
80 | int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry, |
81 | void * element, umode_t mode, int type) | |
82 | { | |
83 | struct sysfs_dirent * sd; | |
84 | ||
85 | sd = sysfs_new_dirent(parent_sd, element); | |
86 | if (!sd) | |
87 | return -ENOMEM; | |
88 | ||
89 | sd->s_mode = mode; | |
90 | sd->s_type = type; | |
91 | sd->s_dentry = dentry; | |
92 | if (dentry) { | |
93 | dentry->d_fsdata = sysfs_get(sd); | |
94 | dentry->d_op = &sysfs_dentry_ops; | |
95 | } | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
100 | static int init_dir(struct inode * inode) | |
101 | { | |
102 | inode->i_op = &sysfs_dir_inode_operations; | |
103 | inode->i_fop = &sysfs_dir_operations; | |
104 | ||
105 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
106 | inode->i_nlink++; | |
107 | return 0; | |
108 | } | |
109 | ||
110 | static int init_file(struct inode * inode) | |
111 | { | |
112 | inode->i_size = PAGE_SIZE; | |
113 | inode->i_fop = &sysfs_file_operations; | |
114 | return 0; | |
115 | } | |
116 | ||
117 | static int init_symlink(struct inode * inode) | |
118 | { | |
119 | inode->i_op = &sysfs_symlink_inode_operations; | |
120 | return 0; | |
121 | } | |
122 | ||
123 | static int create_dir(struct kobject * k, struct dentry * p, | |
124 | const char * n, struct dentry ** d) | |
125 | { | |
126 | int error; | |
127 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; | |
128 | ||
1b1dcc1b | 129 | mutex_lock(&p->d_inode->i_mutex); |
5f45f1a7 | 130 | *d = lookup_one_len(n, p, strlen(n)); |
1da177e4 | 131 | if (!IS_ERR(*d)) { |
c516865c MS |
132 | if (sysfs_dirent_exist(p->d_fsdata, n)) |
133 | error = -EEXIST; | |
134 | else | |
135 | error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, | |
136 | SYSFS_DIR); | |
1da177e4 | 137 | if (!error) { |
6fa5c828 | 138 | error = sysfs_create(*d, mode, init_dir); |
1da177e4 LT |
139 | if (!error) { |
140 | p->d_inode->i_nlink++; | |
141 | (*d)->d_op = &sysfs_dentry_ops; | |
142 | d_rehash(*d); | |
143 | } | |
144 | } | |
6fa5c828 | 145 | if (error && (error != -EEXIST)) { |
e80a5dea SR |
146 | struct sysfs_dirent *sd = (*d)->d_fsdata; |
147 | if (sd) { | |
148 | list_del_init(&sd->s_sibling); | |
149 | sysfs_put(sd); | |
150 | } | |
1da177e4 | 151 | d_drop(*d); |
6fa5c828 | 152 | } |
1da177e4 LT |
153 | dput(*d); |
154 | } else | |
155 | error = PTR_ERR(*d); | |
1b1dcc1b | 156 | mutex_unlock(&p->d_inode->i_mutex); |
1da177e4 LT |
157 | return error; |
158 | } | |
159 | ||
160 | ||
161 | int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d) | |
162 | { | |
163 | return create_dir(k,k->dentry,n,d); | |
164 | } | |
165 | ||
166 | /** | |
167 | * sysfs_create_dir - create a directory for an object. | |
168 | * @parent: parent parent object. | |
169 | * @kobj: object we're creating directory for. | |
170 | */ | |
171 | ||
172 | int sysfs_create_dir(struct kobject * kobj) | |
173 | { | |
174 | struct dentry * dentry = NULL; | |
175 | struct dentry * parent; | |
176 | int error = 0; | |
177 | ||
178 | BUG_ON(!kobj); | |
179 | ||
180 | if (kobj->parent) | |
181 | parent = kobj->parent->dentry; | |
182 | else if (sysfs_mount && sysfs_mount->mnt_sb) | |
183 | parent = sysfs_mount->mnt_sb->s_root; | |
184 | else | |
185 | return -EFAULT; | |
186 | ||
187 | error = create_dir(kobj,parent,kobject_name(kobj),&dentry); | |
188 | if (!error) | |
189 | kobj->dentry = dentry; | |
190 | return error; | |
191 | } | |
192 | ||
193 | /* attaches attribute's sysfs_dirent to the dentry corresponding to the | |
194 | * attribute file | |
195 | */ | |
196 | static int sysfs_attach_attr(struct sysfs_dirent * sd, struct dentry * dentry) | |
197 | { | |
198 | struct attribute * attr = NULL; | |
199 | struct bin_attribute * bin_attr = NULL; | |
200 | int (* init) (struct inode *) = NULL; | |
201 | int error = 0; | |
202 | ||
203 | if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) { | |
204 | bin_attr = sd->s_element; | |
205 | attr = &bin_attr->attr; | |
206 | } else { | |
207 | attr = sd->s_element; | |
208 | init = init_file; | |
209 | } | |
210 | ||
6fa5c828 MS |
211 | dentry->d_fsdata = sysfs_get(sd); |
212 | sd->s_dentry = dentry; | |
1da177e4 | 213 | error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init); |
6fa5c828 MS |
214 | if (error) { |
215 | sysfs_put(sd); | |
1da177e4 | 216 | return error; |
6fa5c828 | 217 | } |
1da177e4 LT |
218 | |
219 | if (bin_attr) { | |
220 | dentry->d_inode->i_size = bin_attr->size; | |
221 | dentry->d_inode->i_fop = &bin_fops; | |
222 | } | |
223 | dentry->d_op = &sysfs_dentry_ops; | |
1da177e4 LT |
224 | d_rehash(dentry); |
225 | ||
226 | return 0; | |
227 | } | |
228 | ||
229 | static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry) | |
230 | { | |
231 | int err = 0; | |
232 | ||
6fa5c828 MS |
233 | dentry->d_fsdata = sysfs_get(sd); |
234 | sd->s_dentry = dentry; | |
1da177e4 LT |
235 | err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink); |
236 | if (!err) { | |
237 | dentry->d_op = &sysfs_dentry_ops; | |
1da177e4 | 238 | d_rehash(dentry); |
6fa5c828 MS |
239 | } else |
240 | sysfs_put(sd); | |
241 | ||
1da177e4 LT |
242 | return err; |
243 | } | |
244 | ||
245 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, | |
246 | struct nameidata *nd) | |
247 | { | |
248 | struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata; | |
249 | struct sysfs_dirent * sd; | |
250 | int err = 0; | |
251 | ||
252 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
253 | if (sd->s_type & SYSFS_NOT_PINNED) { | |
254 | const unsigned char * name = sysfs_get_name(sd); | |
255 | ||
256 | if (strcmp(name, dentry->d_name.name)) | |
257 | continue; | |
258 | ||
259 | if (sd->s_type & SYSFS_KOBJ_LINK) | |
260 | err = sysfs_attach_link(sd, dentry); | |
261 | else | |
262 | err = sysfs_attach_attr(sd, dentry); | |
263 | break; | |
264 | } | |
265 | } | |
266 | ||
267 | return ERR_PTR(err); | |
268 | } | |
269 | ||
270 | struct inode_operations sysfs_dir_inode_operations = { | |
271 | .lookup = sysfs_lookup, | |
988d186d | 272 | .setattr = sysfs_setattr, |
1da177e4 LT |
273 | }; |
274 | ||
275 | static void remove_dir(struct dentry * d) | |
276 | { | |
277 | struct dentry * parent = dget(d->d_parent); | |
278 | struct sysfs_dirent * sd; | |
279 | ||
1b1dcc1b | 280 | mutex_lock(&parent->d_inode->i_mutex); |
1da177e4 LT |
281 | d_delete(d); |
282 | sd = d->d_fsdata; | |
283 | list_del_init(&sd->s_sibling); | |
284 | sysfs_put(sd); | |
285 | if (d->d_inode) | |
286 | simple_rmdir(parent->d_inode,d); | |
287 | ||
288 | pr_debug(" o %s removing done (%d)\n",d->d_name.name, | |
289 | atomic_read(&d->d_count)); | |
290 | ||
1b1dcc1b | 291 | mutex_unlock(&parent->d_inode->i_mutex); |
1da177e4 LT |
292 | dput(parent); |
293 | } | |
294 | ||
295 | void sysfs_remove_subdir(struct dentry * d) | |
296 | { | |
297 | remove_dir(d); | |
298 | } | |
299 | ||
300 | ||
301 | /** | |
302 | * sysfs_remove_dir - remove an object's directory. | |
303 | * @kobj: object. | |
304 | * | |
305 | * The only thing special about this is that we remove any files in | |
306 | * the directory before we remove the directory, and we've inlined | |
307 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
308 | */ | |
309 | ||
310 | void sysfs_remove_dir(struct kobject * kobj) | |
311 | { | |
312 | struct dentry * dentry = dget(kobj->dentry); | |
313 | struct sysfs_dirent * parent_sd; | |
314 | struct sysfs_dirent * sd, * tmp; | |
315 | ||
316 | if (!dentry) | |
317 | return; | |
318 | ||
319 | pr_debug("sysfs %s: removing dir\n",dentry->d_name.name); | |
1b1dcc1b | 320 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
321 | parent_sd = dentry->d_fsdata; |
322 | list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { | |
323 | if (!sd->s_element || !(sd->s_type & SYSFS_NOT_PINNED)) | |
324 | continue; | |
325 | list_del_init(&sd->s_sibling); | |
326 | sysfs_drop_dentry(sd, dentry); | |
327 | sysfs_put(sd); | |
328 | } | |
1b1dcc1b | 329 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
330 | |
331 | remove_dir(dentry); | |
332 | /** | |
333 | * Drop reference from dget() on entrance. | |
334 | */ | |
335 | dput(dentry); | |
641e6f30 | 336 | kobj->dentry = NULL; |
1da177e4 LT |
337 | } |
338 | ||
339 | int sysfs_rename_dir(struct kobject * kobj, const char *new_name) | |
340 | { | |
341 | int error = 0; | |
342 | struct dentry * new_dentry, * parent; | |
343 | ||
344 | if (!strcmp(kobject_name(kobj), new_name)) | |
345 | return -EINVAL; | |
346 | ||
347 | if (!kobj->parent) | |
348 | return -EINVAL; | |
349 | ||
350 | down_write(&sysfs_rename_sem); | |
351 | parent = kobj->parent->dentry; | |
352 | ||
1b1dcc1b | 353 | mutex_lock(&parent->d_inode->i_mutex); |
1da177e4 | 354 | |
5f45f1a7 | 355 | new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); |
1da177e4 LT |
356 | if (!IS_ERR(new_dentry)) { |
357 | if (!new_dentry->d_inode) { | |
358 | error = kobject_set_name(kobj, "%s", new_name); | |
359 | if (!error) { | |
360 | d_add(new_dentry, NULL); | |
361 | d_move(kobj->dentry, new_dentry); | |
362 | } | |
363 | else | |
364 | d_drop(new_dentry); | |
365 | } else | |
366 | error = -EEXIST; | |
367 | dput(new_dentry); | |
368 | } | |
1b1dcc1b | 369 | mutex_unlock(&parent->d_inode->i_mutex); |
1da177e4 LT |
370 | up_write(&sysfs_rename_sem); |
371 | ||
372 | return error; | |
373 | } | |
374 | ||
375 | static int sysfs_dir_open(struct inode *inode, struct file *file) | |
376 | { | |
377 | struct dentry * dentry = file->f_dentry; | |
378 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; | |
379 | ||
1b1dcc1b | 380 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 381 | file->private_data = sysfs_new_dirent(parent_sd, NULL); |
1b1dcc1b | 382 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
383 | |
384 | return file->private_data ? 0 : -ENOMEM; | |
385 | ||
386 | } | |
387 | ||
388 | static int sysfs_dir_close(struct inode *inode, struct file *file) | |
389 | { | |
390 | struct dentry * dentry = file->f_dentry; | |
391 | struct sysfs_dirent * cursor = file->private_data; | |
392 | ||
1b1dcc1b | 393 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 394 | list_del_init(&cursor->s_sibling); |
1b1dcc1b | 395 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
396 | |
397 | release_sysfs_dirent(cursor); | |
398 | ||
399 | return 0; | |
400 | } | |
401 | ||
402 | /* Relationship between s_mode and the DT_xxx types */ | |
403 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
404 | { | |
405 | return (sd->s_mode >> 12) & 15; | |
406 | } | |
407 | ||
408 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
409 | { | |
410 | struct dentry *dentry = filp->f_dentry; | |
411 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; | |
412 | struct sysfs_dirent *cursor = filp->private_data; | |
413 | struct list_head *p, *q = &cursor->s_sibling; | |
414 | ino_t ino; | |
415 | int i = filp->f_pos; | |
416 | ||
417 | switch (i) { | |
418 | case 0: | |
419 | ino = dentry->d_inode->i_ino; | |
420 | if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) | |
421 | break; | |
422 | filp->f_pos++; | |
423 | i++; | |
424 | /* fallthrough */ | |
425 | case 1: | |
426 | ino = parent_ino(dentry); | |
427 | if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) | |
428 | break; | |
429 | filp->f_pos++; | |
430 | i++; | |
431 | /* fallthrough */ | |
432 | default: | |
1bfba4e8 AM |
433 | if (filp->f_pos == 2) |
434 | list_move(q, &parent_sd->s_children); | |
435 | ||
1da177e4 LT |
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 | ||
1bfba4e8 | 457 | list_move(q, p); |
1da177e4 LT |
458 | p = q; |
459 | filp->f_pos++; | |
460 | } | |
461 | } | |
462 | return 0; | |
463 | } | |
464 | ||
465 | static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) | |
466 | { | |
467 | struct dentry * dentry = file->f_dentry; | |
468 | ||
1b1dcc1b | 469 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
470 | switch (origin) { |
471 | case 1: | |
472 | offset += file->f_pos; | |
473 | case 0: | |
474 | if (offset >= 0) | |
475 | break; | |
476 | default: | |
1b1dcc1b | 477 | mutex_unlock(&file->f_dentry->d_inode->i_mutex); |
1da177e4 LT |
478 | return -EINVAL; |
479 | } | |
480 | if (offset != file->f_pos) { | |
481 | file->f_pos = offset; | |
482 | if (file->f_pos >= 2) { | |
483 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
484 | struct sysfs_dirent *cursor = file->private_data; | |
485 | struct list_head *p; | |
486 | loff_t n = file->f_pos - 2; | |
487 | ||
488 | list_del(&cursor->s_sibling); | |
489 | p = sd->s_children.next; | |
490 | while (n && p != &sd->s_children) { | |
491 | struct sysfs_dirent *next; | |
492 | next = list_entry(p, struct sysfs_dirent, | |
493 | s_sibling); | |
494 | if (next->s_element) | |
495 | n--; | |
496 | p = p->next; | |
497 | } | |
498 | list_add_tail(&cursor->s_sibling, p); | |
499 | } | |
500 | } | |
1b1dcc1b | 501 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
502 | return offset; |
503 | } | |
504 | ||
4b6f5d20 | 505 | const struct file_operations sysfs_dir_operations = { |
1da177e4 LT |
506 | .open = sysfs_dir_open, |
507 | .release = sysfs_dir_close, | |
508 | .llseek = sysfs_dir_lseek, | |
509 | .read = generic_read_dir, | |
510 | .readdir = sysfs_readdir, | |
511 | }; |