blob: 61c42430cba3159e5cce02d8675cb2d8c1bec14b [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Christoph Hellwig5f45f1a2005-06-23 00:09:12 -070011#include <linux/namei.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include "sysfs.h"
13
14DECLARE_RWSEM(sysfs_rename_sem);
15
16static 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
28static 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 */
35static 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);
NeilBrown4508a7a2006-03-20 17:53:53 +110046 atomic_set(&sd->s_event, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 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
Martin Waitza5802902006-04-02 13:59:55 +020054/*
Maneesh Sonic5168652006-03-09 19:40:14 +053055 *
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 */
61int 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070080int 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
100static 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
110static 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
117static int init_symlink(struct inode * inode)
118{
119 inode->i_op = &sysfs_symlink_inode_operations;
120 return 0;
121}
122
123static 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
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800129 mutex_lock(&p->d_inode->i_mutex);
Christoph Hellwig5f45f1a2005-06-23 00:09:12 -0700130 *d = lookup_one_len(n, p, strlen(n));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 if (!IS_ERR(*d)) {
Maneesh Sonic5168652006-03-09 19:40:14 +0530132 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 if (!error) {
Maneesh Soni6fa5c822005-05-31 10:38:12 +0530138 error = sysfs_create(*d, mode, init_dir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 if (!error) {
140 p->d_inode->i_nlink++;
141 (*d)->d_op = &sysfs_dentry_ops;
142 d_rehash(*d);
143 }
144 }
Maneesh Soni6fa5c822005-05-31 10:38:12 +0530145 if (error && (error != -EEXIST)) {
Steven Rostedte80a5de2005-11-23 09:15:44 -0500146 struct sysfs_dirent *sd = (*d)->d_fsdata;
147 if (sd) {
148 list_del_init(&sd->s_sibling);
149 sysfs_put(sd);
150 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 d_drop(*d);
Maneesh Soni6fa5c822005-05-31 10:38:12 +0530152 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 dput(*d);
154 } else
155 error = PTR_ERR(*d);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800156 mutex_unlock(&p->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 return error;
158}
159
160
161int 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
172int 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 */
196static 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
Maneesh Soni6fa5c822005-05-31 10:38:12 +0530211 dentry->d_fsdata = sysfs_get(sd);
212 sd->s_dentry = dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 error = sysfs_create(dentry, (attr->mode & S_IALLUGO) | S_IFREG, init);
Maneesh Soni6fa5c822005-05-31 10:38:12 +0530214 if (error) {
215 sysfs_put(sd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 return error;
Maneesh Soni6fa5c822005-05-31 10:38:12 +0530217 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 d_rehash(dentry);
225
226 return 0;
227}
228
229static int sysfs_attach_link(struct sysfs_dirent * sd, struct dentry * dentry)
230{
231 int err = 0;
232
Maneesh Soni6fa5c822005-05-31 10:38:12 +0530233 dentry->d_fsdata = sysfs_get(sd);
234 sd->s_dentry = dentry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 err = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
236 if (!err) {
237 dentry->d_op = &sysfs_dentry_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 d_rehash(dentry);
Maneesh Soni6fa5c822005-05-31 10:38:12 +0530239 } else
240 sysfs_put(sd);
241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 return err;
243}
244
245static 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
270struct inode_operations sysfs_dir_inode_operations = {
271 .lookup = sysfs_lookup,
Maneesh Soni988d1862005-05-31 10:39:14 +0530272 .setattr = sysfs_setattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273};
274
275static void remove_dir(struct dentry * d)
276{
277 struct dentry * parent = dget(d->d_parent);
278 struct sysfs_dirent * sd;
279
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800280 mutex_lock(&parent->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 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
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800291 mutex_unlock(&parent->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 dput(parent);
293}
294
295void 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
310void 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);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800320 mutex_lock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 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 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800329 mutex_unlock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330
331 remove_dir(dentry);
332 /**
333 * Drop reference from dget() on entrance.
334 */
335 dput(dentry);
Greg Kroah-Hartman641e6f32006-03-16 15:44:26 -0800336 kobj->dentry = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337}
338
339int 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
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800353 mutex_lock(&parent->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
Christoph Hellwig5f45f1a2005-06-23 00:09:12 -0700355 new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 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 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800369 mutex_unlock(&parent->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 up_write(&sysfs_rename_sem);
371
372 return error;
373}
374
375static 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
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800380 mutex_lock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 file->private_data = sysfs_new_dirent(parent_sd, NULL);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800382 mutex_unlock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
384 return file->private_data ? 0 : -ENOMEM;
385
386}
387
388static 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
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800393 mutex_lock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 list_del_init(&cursor->s_sibling);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800395 mutex_unlock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
397 release_sysfs_dirent(cursor);
398
399 return 0;
400}
401
402/* Relationship between s_mode and the DT_xxx types */
403static inline unsigned char dt_type(struct sysfs_dirent *sd)
404{
405 return (sd->s_mode >> 12) & 15;
406}
407
408static 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:
Akinobu Mita1bfba4e2006-06-26 00:24:40 -0700433 if (filp->f_pos == 2)
434 list_move(q, &parent_sd->s_children);
435
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 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
Akinobu Mita1bfba4e2006-06-26 00:24:40 -0700457 list_move(q, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 p = q;
459 filp->f_pos++;
460 }
461 }
462 return 0;
463}
464
465static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin)
466{
467 struct dentry * dentry = file->f_dentry;
468
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800469 mutex_lock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 switch (origin) {
471 case 1:
472 offset += file->f_pos;
473 case 0:
474 if (offset >= 0)
475 break;
476 default:
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800477 mutex_unlock(&file->f_dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 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 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800501 mutex_unlock(&dentry->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 return offset;
503}
504
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800505const struct file_operations sysfs_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 .open = sysfs_dir_open,
507 .release = sysfs_dir_close,
508 .llseek = sysfs_dir_lseek,
509 .read = generic_read_dir,
510 .readdir = sysfs_readdir,
511};