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