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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> |
2b611bb7 | 12 | #include <linux/idr.h> |
94bebf4d | 13 | #include <asm/semaphore.h> |
1da177e4 LT |
14 | #include "sysfs.h" |
15 | ||
16 | DECLARE_RWSEM(sysfs_rename_sem); | |
dd14cbc9 | 17 | spinlock_t sysfs_lock = SPIN_LOCK_UNLOCKED; |
aecdceda | 18 | spinlock_t kobj_sysfs_assoc_lock = SPIN_LOCK_UNLOCKED; |
1da177e4 | 19 | |
2b611bb7 TH |
20 | static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED; |
21 | static DEFINE_IDA(sysfs_ino_ida); | |
22 | ||
42b37df6 | 23 | static int sysfs_alloc_ino(ino_t *pino) |
2b611bb7 TH |
24 | { |
25 | int ino, rc; | |
26 | ||
27 | retry: | |
28 | spin_lock(&sysfs_ino_lock); | |
29 | rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino); | |
30 | spin_unlock(&sysfs_ino_lock); | |
31 | ||
32 | if (rc == -EAGAIN) { | |
33 | if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL)) | |
34 | goto retry; | |
35 | rc = -ENOMEM; | |
36 | } | |
37 | ||
38 | *pino = ino; | |
39 | return rc; | |
40 | } | |
41 | ||
42 | static void sysfs_free_ino(ino_t ino) | |
43 | { | |
44 | spin_lock(&sysfs_ino_lock); | |
45 | ida_remove(&sysfs_ino_ida, ino); | |
46 | spin_unlock(&sysfs_ino_lock); | |
47 | } | |
48 | ||
fa7f912a TH |
49 | void release_sysfs_dirent(struct sysfs_dirent * sd) |
50 | { | |
13b3086d TH |
51 | struct sysfs_dirent *parent_sd; |
52 | ||
53 | repeat: | |
54 | parent_sd = sd->s_parent; | |
55 | ||
0ab66088 TH |
56 | /* If @sd is being released after deletion, s_active is write |
57 | * locked. If @sd is cursor for directory walk or being | |
58 | * released prematurely, s_active has no reader or writer. | |
59 | * | |
60 | * sysfs_deactivate() lies to lockdep that s_active is | |
61 | * unlocked immediately. Lie one more time to cover the | |
62 | * previous lie. | |
63 | */ | |
64 | if (!down_write_trylock(&sd->s_active)) | |
65 | rwsem_acquire(&sd->s_active.dep_map, | |
66 | SYSFS_S_ACTIVE_DEACTIVATE, 0, _RET_IP_); | |
67 | up_write(&sd->s_active); | |
68 | ||
3e519038 | 69 | if (sd->s_type & SYSFS_KOBJ_LINK) |
2b29ac25 | 70 | sysfs_put(sd->s_elem.symlink.target_sd); |
0c096b50 TH |
71 | if (sd->s_type & SYSFS_COPY_NAME) |
72 | kfree(sd->s_name); | |
fa7f912a | 73 | kfree(sd->s_iattr); |
2b611bb7 | 74 | sysfs_free_ino(sd->s_ino); |
fa7f912a | 75 | kmem_cache_free(sysfs_dir_cachep, sd); |
13b3086d TH |
76 | |
77 | sd = parent_sd; | |
78 | if (sd && atomic_dec_and_test(&sd->s_count)) | |
79 | goto repeat; | |
fa7f912a TH |
80 | } |
81 | ||
1da177e4 LT |
82 | static void sysfs_d_iput(struct dentry * dentry, struct inode * inode) |
83 | { | |
84 | struct sysfs_dirent * sd = dentry->d_fsdata; | |
85 | ||
86 | if (sd) { | |
dd14cbc9 TH |
87 | /* sd->s_dentry is protected with sysfs_lock. This |
88 | * allows sysfs_drop_dentry() to dereference it. | |
89 | */ | |
90 | spin_lock(&sysfs_lock); | |
91 | ||
92 | /* The dentry might have been deleted or another | |
93 | * lookup could have happened updating sd->s_dentry to | |
94 | * point the new dentry. Ignore if it isn't pointing | |
95 | * to this dentry. | |
96 | */ | |
97 | if (sd->s_dentry == dentry) | |
98 | sd->s_dentry = NULL; | |
99 | spin_unlock(&sysfs_lock); | |
1da177e4 LT |
100 | sysfs_put(sd); |
101 | } | |
102 | iput(inode); | |
103 | } | |
104 | ||
105 | static struct dentry_operations sysfs_dentry_ops = { | |
106 | .d_iput = sysfs_d_iput, | |
107 | }; | |
108 | ||
3e519038 | 109 | struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) |
1da177e4 | 110 | { |
0c096b50 TH |
111 | char *dup_name = NULL; |
112 | struct sysfs_dirent *sd = NULL; | |
113 | ||
114 | if (type & SYSFS_COPY_NAME) { | |
115 | name = dup_name = kstrdup(name, GFP_KERNEL); | |
116 | if (!name) | |
117 | goto err_out; | |
118 | } | |
1da177e4 | 119 | |
c3762229 | 120 | sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); |
1da177e4 | 121 | if (!sd) |
0c096b50 | 122 | goto err_out; |
1da177e4 | 123 | |
0c096b50 TH |
124 | if (sysfs_alloc_ino(&sd->s_ino)) |
125 | goto err_out; | |
2b611bb7 | 126 | |
1da177e4 | 127 | atomic_set(&sd->s_count, 1); |
eea3f891 | 128 | atomic_set(&sd->s_event, 1); |
0ab66088 | 129 | init_rwsem(&sd->s_active); |
1da177e4 | 130 | INIT_LIST_HEAD(&sd->s_children); |
b592fcfe | 131 | INIT_LIST_HEAD(&sd->s_sibling); |
a26cd722 | 132 | |
0c096b50 | 133 | sd->s_name = name; |
a26cd722 TH |
134 | sd->s_mode = mode; |
135 | sd->s_type = type; | |
1da177e4 LT |
136 | |
137 | return sd; | |
0c096b50 TH |
138 | |
139 | err_out: | |
140 | kfree(dup_name); | |
141 | kmem_cache_free(sysfs_dir_cachep, sd); | |
142 | return NULL; | |
1da177e4 LT |
143 | } |
144 | ||
198a2a84 TH |
145 | static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry) |
146 | { | |
147 | dentry->d_op = &sysfs_dentry_ops; | |
148 | dentry->d_fsdata = sysfs_get(sd); | |
149 | ||
150 | /* protect sd->s_dentry against sysfs_d_iput */ | |
151 | spin_lock(&sysfs_lock); | |
152 | sd->s_dentry = dentry; | |
153 | spin_unlock(&sysfs_lock); | |
154 | ||
155 | d_rehash(dentry); | |
156 | } | |
157 | ||
a26cd722 TH |
158 | void sysfs_attach_dirent(struct sysfs_dirent *sd, |
159 | struct sysfs_dirent *parent_sd, struct dentry *dentry) | |
b592fcfe | 160 | { |
198a2a84 TH |
161 | if (dentry) |
162 | sysfs_attach_dentry(sd, dentry); | |
b592fcfe | 163 | |
13b3086d TH |
164 | if (parent_sd) { |
165 | sd->s_parent = sysfs_get(parent_sd); | |
a26cd722 | 166 | list_add(&sd->s_sibling, &parent_sd->s_children); |
13b3086d | 167 | } |
b592fcfe EB |
168 | } |
169 | ||
a580290c | 170 | /* |
c516865c MS |
171 | * |
172 | * Return -EEXIST if there is already a sysfs element with the same name for | |
173 | * the same parent. | |
174 | * | |
175 | * called with parent inode's i_mutex held | |
176 | */ | |
177 | int sysfs_dirent_exist(struct sysfs_dirent *parent_sd, | |
178 | const unsigned char *new) | |
179 | { | |
180 | struct sysfs_dirent * sd; | |
181 | ||
182 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
3e519038 | 183 | if (sd->s_type) { |
0c096b50 | 184 | if (strcmp(sd->s_name, new)) |
c516865c MS |
185 | continue; |
186 | else | |
187 | return -EEXIST; | |
188 | } | |
189 | } | |
190 | ||
191 | return 0; | |
192 | } | |
193 | ||
dfeb9fb0 TH |
194 | static int create_dir(struct kobject *kobj, struct dentry *parent, |
195 | const char *name, struct dentry **p_dentry) | |
1da177e4 LT |
196 | { |
197 | int error; | |
198 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; | |
dfeb9fb0 | 199 | struct dentry *dentry; |
fc9f54b9 | 200 | struct inode *inode; |
dfeb9fb0 | 201 | struct sysfs_dirent *sd; |
1da177e4 | 202 | |
dfeb9fb0 TH |
203 | mutex_lock(&parent->d_inode->i_mutex); |
204 | ||
fc9f54b9 | 205 | /* allocate */ |
dfeb9fb0 TH |
206 | dentry = lookup_one_len(name, parent, strlen(name)); |
207 | if (IS_ERR(dentry)) { | |
208 | error = PTR_ERR(dentry); | |
209 | goto out_unlock; | |
210 | } | |
211 | ||
212 | error = -EEXIST; | |
fc9f54b9 | 213 | if (dentry->d_inode) |
dfeb9fb0 TH |
214 | goto out_dput; |
215 | ||
a26cd722 | 216 | error = -ENOMEM; |
3e519038 | 217 | sd = sysfs_new_dirent(name, mode, SYSFS_DIR); |
a26cd722 | 218 | if (!sd) |
dfeb9fb0 | 219 | goto out_drop; |
3e519038 | 220 | sd->s_elem.dir.kobj = kobj; |
dfeb9fb0 | 221 | |
8312a8d7 | 222 | inode = sysfs_get_inode(sd); |
fc9f54b9 | 223 | if (!inode) |
dfeb9fb0 TH |
224 | goto out_sput; |
225 | ||
8312a8d7 TH |
226 | if (inode->i_state & I_NEW) { |
227 | inode->i_op = &sysfs_dir_inode_operations; | |
228 | inode->i_fop = &sysfs_dir_operations; | |
229 | /* directory inodes start off with i_nlink == 2 (for ".") */ | |
230 | inc_nlink(inode); | |
231 | } | |
fc9f54b9 TH |
232 | |
233 | /* link in */ | |
234 | error = -EEXIST; | |
235 | if (sysfs_dirent_exist(parent->d_fsdata, name)) | |
236 | goto out_iput; | |
237 | ||
238 | sysfs_instantiate(dentry, inode); | |
dfeb9fb0 | 239 | inc_nlink(parent->d_inode); |
198a2a84 | 240 | sysfs_attach_dirent(sd, parent->d_fsdata, dentry); |
dfeb9fb0 TH |
241 | |
242 | *p_dentry = dentry; | |
243 | error = 0; | |
fc9f54b9 | 244 | goto out_unlock; /* pin directory dentry in core */ |
dfeb9fb0 | 245 | |
fc9f54b9 TH |
246 | out_iput: |
247 | iput(inode); | |
dfeb9fb0 | 248 | out_sput: |
dfeb9fb0 TH |
249 | sysfs_put(sd); |
250 | out_drop: | |
251 | d_drop(dentry); | |
252 | out_dput: | |
253 | dput(dentry); | |
254 | out_unlock: | |
255 | mutex_unlock(&parent->d_inode->i_mutex); | |
1da177e4 LT |
256 | return error; |
257 | } | |
258 | ||
259 | ||
260 | int sysfs_create_subdir(struct kobject * k, const char * n, struct dentry ** d) | |
261 | { | |
262 | return create_dir(k,k->dentry,n,d); | |
263 | } | |
264 | ||
265 | /** | |
266 | * sysfs_create_dir - create a directory for an object. | |
1da177e4 | 267 | * @kobj: object we're creating directory for. |
b592fcfe | 268 | * @shadow_parent: parent parent object. |
1da177e4 LT |
269 | */ |
270 | ||
b592fcfe | 271 | int sysfs_create_dir(struct kobject * kobj, struct dentry *shadow_parent) |
1da177e4 LT |
272 | { |
273 | struct dentry * dentry = NULL; | |
274 | struct dentry * parent; | |
275 | int error = 0; | |
276 | ||
277 | BUG_ON(!kobj); | |
278 | ||
b592fcfe EB |
279 | if (shadow_parent) |
280 | parent = shadow_parent; | |
281 | else if (kobj->parent) | |
1da177e4 LT |
282 | parent = kobj->parent->dentry; |
283 | else if (sysfs_mount && sysfs_mount->mnt_sb) | |
284 | parent = sysfs_mount->mnt_sb->s_root; | |
285 | else | |
286 | return -EFAULT; | |
287 | ||
288 | error = create_dir(kobj,parent,kobject_name(kobj),&dentry); | |
289 | if (!error) | |
290 | kobj->dentry = dentry; | |
291 | return error; | |
292 | } | |
293 | ||
1da177e4 LT |
294 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, |
295 | struct nameidata *nd) | |
296 | { | |
297 | struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata; | |
298 | struct sysfs_dirent * sd; | |
fc9f54b9 TH |
299 | struct inode *inode; |
300 | int found = 0; | |
1da177e4 LT |
301 | |
302 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
fc9f54b9 TH |
303 | if ((sd->s_type & SYSFS_NOT_PINNED) && |
304 | !strcmp(sd->s_name, dentry->d_name.name)) { | |
305 | found = 1; | |
1da177e4 LT |
306 | break; |
307 | } | |
308 | } | |
309 | ||
fc9f54b9 TH |
310 | /* no such entry */ |
311 | if (!found) | |
312 | return NULL; | |
313 | ||
314 | /* attach dentry and inode */ | |
8312a8d7 | 315 | inode = sysfs_get_inode(sd); |
fc9f54b9 TH |
316 | if (!inode) |
317 | return ERR_PTR(-ENOMEM); | |
318 | ||
8312a8d7 TH |
319 | if (inode->i_state & I_NEW) { |
320 | /* initialize inode according to type */ | |
321 | if (sd->s_type & SYSFS_KOBJ_ATTR) { | |
322 | inode->i_size = PAGE_SIZE; | |
323 | inode->i_fop = &sysfs_file_operations; | |
324 | } else if (sd->s_type & SYSFS_KOBJ_BIN_ATTR) { | |
325 | struct bin_attribute *bin_attr = | |
326 | sd->s_elem.bin_attr.bin_attr; | |
327 | inode->i_size = bin_attr->size; | |
328 | inode->i_fop = &bin_fops; | |
329 | } else if (sd->s_type & SYSFS_KOBJ_LINK) | |
330 | inode->i_op = &sysfs_symlink_inode_operations; | |
331 | } | |
fc9f54b9 TH |
332 | |
333 | sysfs_instantiate(dentry, inode); | |
334 | sysfs_attach_dentry(sd, dentry); | |
335 | ||
336 | return NULL; | |
1da177e4 LT |
337 | } |
338 | ||
c5ef1c42 | 339 | const struct inode_operations sysfs_dir_inode_operations = { |
1da177e4 | 340 | .lookup = sysfs_lookup, |
988d186d | 341 | .setattr = sysfs_setattr, |
1da177e4 LT |
342 | }; |
343 | ||
344 | static void remove_dir(struct dentry * d) | |
345 | { | |
dbde0fcf TH |
346 | struct dentry *parent = d->d_parent; |
347 | struct sysfs_dirent *sd = d->d_fsdata; | |
1da177e4 | 348 | |
1b1dcc1b | 349 | mutex_lock(&parent->d_inode->i_mutex); |
dbde0fcf | 350 | |
1da177e4 | 351 | list_del_init(&sd->s_sibling); |
1da177e4 LT |
352 | |
353 | pr_debug(" o %s removing done (%d)\n",d->d_name.name, | |
354 | atomic_read(&d->d_count)); | |
355 | ||
1b1dcc1b | 356 | mutex_unlock(&parent->d_inode->i_mutex); |
0ab66088 | 357 | |
dbde0fcf | 358 | sysfs_drop_dentry(sd); |
0ab66088 TH |
359 | sysfs_deactivate(sd); |
360 | sysfs_put(sd); | |
1da177e4 LT |
361 | } |
362 | ||
363 | void sysfs_remove_subdir(struct dentry * d) | |
364 | { | |
365 | remove_dir(d); | |
366 | } | |
367 | ||
368 | ||
b592fcfe | 369 | static void __sysfs_remove_dir(struct dentry *dentry) |
1da177e4 | 370 | { |
0ab66088 | 371 | LIST_HEAD(removed); |
1da177e4 LT |
372 | struct sysfs_dirent * parent_sd; |
373 | struct sysfs_dirent * sd, * tmp; | |
374 | ||
375 | if (!dentry) | |
376 | return; | |
377 | ||
378 | pr_debug("sysfs %s: removing dir\n",dentry->d_name.name); | |
1b1dcc1b | 379 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
380 | parent_sd = dentry->d_fsdata; |
381 | list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { | |
3e519038 | 382 | if (!sd->s_type || !(sd->s_type & SYSFS_NOT_PINNED)) |
1da177e4 | 383 | continue; |
0ab66088 | 384 | list_move(&sd->s_sibling, &removed); |
1da177e4 | 385 | } |
1b1dcc1b | 386 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 | 387 | |
0ab66088 TH |
388 | list_for_each_entry_safe(sd, tmp, &removed, s_sibling) { |
389 | list_del_init(&sd->s_sibling); | |
dbde0fcf | 390 | sysfs_drop_dentry(sd); |
0ab66088 TH |
391 | sysfs_deactivate(sd); |
392 | sysfs_put(sd); | |
393 | } | |
394 | ||
1da177e4 | 395 | remove_dir(dentry); |
b592fcfe EB |
396 | } |
397 | ||
398 | /** | |
399 | * sysfs_remove_dir - remove an object's directory. | |
400 | * @kobj: object. | |
401 | * | |
402 | * The only thing special about this is that we remove any files in | |
403 | * the directory before we remove the directory, and we've inlined | |
404 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
405 | */ | |
406 | ||
407 | void sysfs_remove_dir(struct kobject * kobj) | |
408 | { | |
aecdceda TH |
409 | struct dentry *d = kobj->dentry; |
410 | ||
411 | spin_lock(&kobj_sysfs_assoc_lock); | |
641e6f30 | 412 | kobj->dentry = NULL; |
aecdceda TH |
413 | spin_unlock(&kobj_sysfs_assoc_lock); |
414 | ||
415 | __sysfs_remove_dir(d); | |
1da177e4 LT |
416 | } |
417 | ||
b592fcfe EB |
418 | int sysfs_rename_dir(struct kobject * kobj, struct dentry *new_parent, |
419 | const char *new_name) | |
1da177e4 | 420 | { |
0c096b50 TH |
421 | struct sysfs_dirent *sd = kobj->dentry->d_fsdata; |
422 | struct sysfs_dirent *parent_sd = new_parent->d_fsdata; | |
423 | struct dentry *new_dentry; | |
424 | char *dup_name; | |
996b7376 | 425 | int error; |
1da177e4 | 426 | |
b592fcfe EB |
427 | if (!new_parent) |
428 | return -EFAULT; | |
1da177e4 LT |
429 | |
430 | down_write(&sysfs_rename_sem); | |
b592fcfe | 431 | mutex_lock(&new_parent->d_inode->i_mutex); |
1da177e4 | 432 | |
b592fcfe | 433 | new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name)); |
996b7376 TH |
434 | if (IS_ERR(new_dentry)) { |
435 | error = PTR_ERR(new_dentry); | |
436 | goto out_unlock; | |
1da177e4 | 437 | } |
996b7376 TH |
438 | |
439 | /* By allowing two different directories with the same | |
440 | * d_parent we allow this routine to move between different | |
441 | * shadows of the same directory | |
442 | */ | |
443 | error = -EINVAL; | |
444 | if (kobj->dentry->d_parent->d_inode != new_parent->d_inode || | |
445 | new_dentry->d_parent->d_inode != new_parent->d_inode || | |
446 | new_dentry == kobj->dentry) | |
447 | goto out_dput; | |
448 | ||
449 | error = -EEXIST; | |
450 | if (new_dentry->d_inode) | |
451 | goto out_dput; | |
452 | ||
0c096b50 TH |
453 | /* rename kobject and sysfs_dirent */ |
454 | error = -ENOMEM; | |
455 | new_name = dup_name = kstrdup(new_name, GFP_KERNEL); | |
456 | if (!new_name) | |
457 | goto out_drop; | |
458 | ||
996b7376 TH |
459 | error = kobject_set_name(kobj, "%s", new_name); |
460 | if (error) | |
0c096b50 | 461 | goto out_free; |
996b7376 | 462 | |
0c096b50 TH |
463 | kfree(sd->s_name); |
464 | sd->s_name = new_name; | |
465 | ||
466 | /* move under the new parent */ | |
996b7376 TH |
467 | d_add(new_dentry, NULL); |
468 | d_move(kobj->dentry, new_dentry); | |
469 | ||
996b7376 | 470 | list_del_init(&sd->s_sibling); |
7f7cfffe TH |
471 | sysfs_get(parent_sd); |
472 | sysfs_put(sd->s_parent); | |
473 | sd->s_parent = parent_sd; | |
996b7376 TH |
474 | list_add(&sd->s_sibling, &parent_sd->s_children); |
475 | ||
476 | error = 0; | |
477 | goto out_unlock; | |
478 | ||
0c096b50 TH |
479 | out_free: |
480 | kfree(dup_name); | |
996b7376 TH |
481 | out_drop: |
482 | d_drop(new_dentry); | |
483 | out_dput: | |
484 | dput(new_dentry); | |
485 | out_unlock: | |
b592fcfe | 486 | mutex_unlock(&new_parent->d_inode->i_mutex); |
1da177e4 | 487 | up_write(&sysfs_rename_sem); |
1da177e4 LT |
488 | return error; |
489 | } | |
490 | ||
8a82472f CH |
491 | int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent) |
492 | { | |
493 | struct dentry *old_parent_dentry, *new_parent_dentry, *new_dentry; | |
494 | struct sysfs_dirent *new_parent_sd, *sd; | |
495 | int error; | |
496 | ||
8a82472f CH |
497 | old_parent_dentry = kobj->parent ? |
498 | kobj->parent->dentry : sysfs_mount->mnt_sb->s_root; | |
c744aeae CH |
499 | new_parent_dentry = new_parent ? |
500 | new_parent->dentry : sysfs_mount->mnt_sb->s_root; | |
8a82472f | 501 | |
0de1517e ML |
502 | if (old_parent_dentry->d_inode == new_parent_dentry->d_inode) |
503 | return 0; /* nothing to move */ | |
8a82472f CH |
504 | again: |
505 | mutex_lock(&old_parent_dentry->d_inode->i_mutex); | |
506 | if (!mutex_trylock(&new_parent_dentry->d_inode->i_mutex)) { | |
507 | mutex_unlock(&old_parent_dentry->d_inode->i_mutex); | |
508 | goto again; | |
509 | } | |
510 | ||
511 | new_parent_sd = new_parent_dentry->d_fsdata; | |
512 | sd = kobj->dentry->d_fsdata; | |
513 | ||
514 | new_dentry = lookup_one_len(kobj->name, new_parent_dentry, | |
515 | strlen(kobj->name)); | |
516 | if (IS_ERR(new_dentry)) { | |
517 | error = PTR_ERR(new_dentry); | |
518 | goto out; | |
519 | } else | |
520 | error = 0; | |
521 | d_add(new_dentry, NULL); | |
522 | d_move(kobj->dentry, new_dentry); | |
523 | dput(new_dentry); | |
524 | ||
525 | /* Remove from old parent's list and insert into new parent's list. */ | |
526 | list_del_init(&sd->s_sibling); | |
7f7cfffe TH |
527 | sysfs_get(new_parent_sd); |
528 | sysfs_put(sd->s_parent); | |
529 | sd->s_parent = new_parent_sd; | |
8a82472f CH |
530 | list_add(&sd->s_sibling, &new_parent_sd->s_children); |
531 | ||
532 | out: | |
533 | mutex_unlock(&new_parent_dentry->d_inode->i_mutex); | |
534 | mutex_unlock(&old_parent_dentry->d_inode->i_mutex); | |
535 | ||
536 | return error; | |
537 | } | |
538 | ||
1da177e4 LT |
539 | static int sysfs_dir_open(struct inode *inode, struct file *file) |
540 | { | |
f427f5d5 | 541 | struct dentry * dentry = file->f_path.dentry; |
1da177e4 | 542 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
a26cd722 | 543 | struct sysfs_dirent * sd; |
1da177e4 | 544 | |
1b1dcc1b | 545 | mutex_lock(&dentry->d_inode->i_mutex); |
3e519038 | 546 | sd = sysfs_new_dirent("_DIR_", 0, 0); |
a26cd722 TH |
547 | if (sd) |
548 | sysfs_attach_dirent(sd, parent_sd, NULL); | |
1b1dcc1b | 549 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 | 550 | |
a26cd722 TH |
551 | file->private_data = sd; |
552 | return sd ? 0 : -ENOMEM; | |
1da177e4 LT |
553 | } |
554 | ||
555 | static int sysfs_dir_close(struct inode *inode, struct file *file) | |
556 | { | |
f427f5d5 | 557 | struct dentry * dentry = file->f_path.dentry; |
1da177e4 LT |
558 | struct sysfs_dirent * cursor = file->private_data; |
559 | ||
1b1dcc1b | 560 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 561 | list_del_init(&cursor->s_sibling); |
1b1dcc1b | 562 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
563 | |
564 | release_sysfs_dirent(cursor); | |
565 | ||
566 | return 0; | |
567 | } | |
568 | ||
569 | /* Relationship between s_mode and the DT_xxx types */ | |
570 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
571 | { | |
572 | return (sd->s_mode >> 12) & 15; | |
573 | } | |
574 | ||
575 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
576 | { | |
f427f5d5 | 577 | struct dentry *dentry = filp->f_path.dentry; |
1da177e4 LT |
578 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
579 | struct sysfs_dirent *cursor = filp->private_data; | |
580 | struct list_head *p, *q = &cursor->s_sibling; | |
581 | ino_t ino; | |
582 | int i = filp->f_pos; | |
583 | ||
584 | switch (i) { | |
585 | case 0: | |
dc351252 | 586 | ino = parent_sd->s_ino; |
1da177e4 LT |
587 | if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) |
588 | break; | |
589 | filp->f_pos++; | |
590 | i++; | |
591 | /* fallthrough */ | |
592 | case 1: | |
13b3086d TH |
593 | if (parent_sd->s_parent) |
594 | ino = parent_sd->s_parent->s_ino; | |
595 | else | |
596 | ino = parent_sd->s_ino; | |
1da177e4 LT |
597 | if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) |
598 | break; | |
599 | filp->f_pos++; | |
600 | i++; | |
601 | /* fallthrough */ | |
602 | default: | |
1bfba4e8 AM |
603 | if (filp->f_pos == 2) |
604 | list_move(q, &parent_sd->s_children); | |
605 | ||
1da177e4 LT |
606 | for (p=q->next; p!= &parent_sd->s_children; p=p->next) { |
607 | struct sysfs_dirent *next; | |
608 | const char * name; | |
609 | int len; | |
610 | ||
611 | next = list_entry(p, struct sysfs_dirent, | |
612 | s_sibling); | |
3e519038 | 613 | if (!next->s_type) |
1da177e4 LT |
614 | continue; |
615 | ||
0c096b50 | 616 | name = next->s_name; |
1da177e4 | 617 | len = strlen(name); |
dc351252 | 618 | ino = next->s_ino; |
1da177e4 LT |
619 | |
620 | if (filldir(dirent, name, len, filp->f_pos, ino, | |
621 | dt_type(next)) < 0) | |
622 | return 0; | |
623 | ||
1bfba4e8 | 624 | list_move(q, p); |
1da177e4 LT |
625 | p = q; |
626 | filp->f_pos++; | |
627 | } | |
628 | } | |
629 | return 0; | |
630 | } | |
631 | ||
632 | static loff_t sysfs_dir_lseek(struct file * file, loff_t offset, int origin) | |
633 | { | |
f427f5d5 | 634 | struct dentry * dentry = file->f_path.dentry; |
1da177e4 | 635 | |
1b1dcc1b | 636 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
637 | switch (origin) { |
638 | case 1: | |
639 | offset += file->f_pos; | |
640 | case 0: | |
641 | if (offset >= 0) | |
642 | break; | |
643 | default: | |
f427f5d5 | 644 | mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); |
1da177e4 LT |
645 | return -EINVAL; |
646 | } | |
647 | if (offset != file->f_pos) { | |
648 | file->f_pos = offset; | |
649 | if (file->f_pos >= 2) { | |
650 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
651 | struct sysfs_dirent *cursor = file->private_data; | |
652 | struct list_head *p; | |
653 | loff_t n = file->f_pos - 2; | |
654 | ||
655 | list_del(&cursor->s_sibling); | |
656 | p = sd->s_children.next; | |
657 | while (n && p != &sd->s_children) { | |
658 | struct sysfs_dirent *next; | |
659 | next = list_entry(p, struct sysfs_dirent, | |
660 | s_sibling); | |
3e519038 | 661 | if (next->s_type) |
1da177e4 LT |
662 | n--; |
663 | p = p->next; | |
664 | } | |
665 | list_add_tail(&cursor->s_sibling, p); | |
666 | } | |
667 | } | |
1b1dcc1b | 668 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
669 | return offset; |
670 | } | |
671 | ||
b592fcfe EB |
672 | |
673 | /** | |
674 | * sysfs_make_shadowed_dir - Setup so a directory can be shadowed | |
675 | * @kobj: object we're creating shadow of. | |
676 | */ | |
677 | ||
678 | int sysfs_make_shadowed_dir(struct kobject *kobj, | |
679 | void * (*follow_link)(struct dentry *, struct nameidata *)) | |
680 | { | |
681 | struct inode *inode; | |
682 | struct inode_operations *i_op; | |
683 | ||
684 | inode = kobj->dentry->d_inode; | |
685 | if (inode->i_op != &sysfs_dir_inode_operations) | |
686 | return -EINVAL; | |
687 | ||
688 | i_op = kmalloc(sizeof(*i_op), GFP_KERNEL); | |
689 | if (!i_op) | |
690 | return -ENOMEM; | |
691 | ||
692 | memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op)); | |
693 | i_op->follow_link = follow_link; | |
694 | ||
695 | /* Locking of inode->i_op? | |
696 | * Since setting i_op is a single word write and they | |
697 | * are atomic we should be ok here. | |
698 | */ | |
699 | inode->i_op = i_op; | |
700 | return 0; | |
701 | } | |
702 | ||
703 | /** | |
704 | * sysfs_create_shadow_dir - create a shadow directory for an object. | |
705 | * @kobj: object we're creating directory for. | |
706 | * | |
707 | * sysfs_make_shadowed_dir must already have been called on this | |
708 | * directory. | |
709 | */ | |
710 | ||
711 | struct dentry *sysfs_create_shadow_dir(struct kobject *kobj) | |
712 | { | |
13b3086d TH |
713 | struct dentry *dir = kobj->dentry; |
714 | struct inode *inode = dir->d_inode; | |
715 | struct dentry *parent = dir->d_parent; | |
716 | struct sysfs_dirent *parent_sd = parent->d_fsdata; | |
717 | struct dentry *shadow; | |
b592fcfe | 718 | struct sysfs_dirent *sd; |
b592fcfe | 719 | |
b592fcfe EB |
720 | shadow = ERR_PTR(-EINVAL); |
721 | if (!sysfs_is_shadowed_inode(inode)) | |
722 | goto out; | |
723 | ||
724 | shadow = d_alloc(parent, &dir->d_name); | |
725 | if (!shadow) | |
726 | goto nomem; | |
727 | ||
3e519038 | 728 | sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR); |
b592fcfe EB |
729 | if (!sd) |
730 | goto nomem; | |
3e519038 | 731 | sd->s_elem.dir.kobj = kobj; |
13b3086d TH |
732 | /* point to parent_sd but don't attach to it */ |
733 | sd->s_parent = sysfs_get(parent_sd); | |
a26cd722 | 734 | sysfs_attach_dirent(sd, NULL, shadow); |
b592fcfe EB |
735 | |
736 | d_instantiate(shadow, igrab(inode)); | |
737 | inc_nlink(inode); | |
738 | inc_nlink(parent->d_inode); | |
b592fcfe EB |
739 | |
740 | dget(shadow); /* Extra count - pin the dentry in core */ | |
741 | ||
742 | out: | |
743 | return shadow; | |
744 | nomem: | |
745 | dput(shadow); | |
746 | shadow = ERR_PTR(-ENOMEM); | |
747 | goto out; | |
748 | } | |
749 | ||
750 | /** | |
751 | * sysfs_remove_shadow_dir - remove an object's directory. | |
752 | * @shadow: dentry of shadow directory | |
753 | * | |
754 | * The only thing special about this is that we remove any files in | |
755 | * the directory before we remove the directory, and we've inlined | |
756 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
757 | */ | |
758 | ||
759 | void sysfs_remove_shadow_dir(struct dentry *shadow) | |
760 | { | |
761 | __sysfs_remove_dir(shadow); | |
762 | } | |
763 | ||
4b6f5d20 | 764 | const struct file_operations sysfs_dir_operations = { |
1da177e4 LT |
765 | .open = sysfs_dir_open, |
766 | .release = sysfs_dir_close, | |
767 | .llseek = sysfs_dir_lseek, | |
768 | .read = generic_read_dir, | |
769 | .readdir = sysfs_readdir, | |
770 | }; |