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