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Commit | Line | Data |
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1da177e4 | 1 | /* |
6d66f5cd TH |
2 | * fs/sysfs/dir.c - sysfs core and dir operation implementation |
3 | * | |
4 | * Copyright (c) 2001-3 Patrick Mochel | |
5 | * Copyright (c) 2007 SUSE Linux Products GmbH | |
6 | * Copyright (c) 2007 Tejun Heo <teheo@suse.de> | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | * | |
10 | * Please see Documentation/filesystems/sysfs.txt for more information. | |
1da177e4 LT |
11 | */ |
12 | ||
13 | #undef DEBUG | |
14 | ||
15 | #include <linux/fs.h> | |
16 | #include <linux/mount.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/kobject.h> | |
5f45f1a7 | 19 | #include <linux/namei.h> |
2b611bb7 | 20 | #include <linux/idr.h> |
8619f979 | 21 | #include <linux/completion.h> |
869512ab | 22 | #include <linux/mutex.h> |
c6f87733 | 23 | #include <linux/slab.h> |
4c3da220 | 24 | #include <linux/security.h> |
1da177e4 LT |
25 | #include "sysfs.h" |
26 | ||
3007e997 | 27 | DEFINE_MUTEX(sysfs_mutex); |
932ea2e3 | 28 | DEFINE_MUTEX(sysfs_rename_mutex); |
f7a75f0a | 29 | DEFINE_SPINLOCK(sysfs_assoc_lock); |
1da177e4 | 30 | |
f7a75f0a | 31 | static DEFINE_SPINLOCK(sysfs_ino_lock); |
2b611bb7 TH |
32 | static DEFINE_IDA(sysfs_ino_ida); |
33 | ||
0c73f18b TH |
34 | /** |
35 | * sysfs_link_sibling - link sysfs_dirent into sibling list | |
36 | * @sd: sysfs_dirent of interest | |
37 | * | |
38 | * Link @sd into its sibling list which starts from | |
bc747f37 | 39 | * sd->s_parent->s_dir.children. |
0c73f18b TH |
40 | * |
41 | * Locking: | |
3007e997 | 42 | * mutex_lock(sysfs_mutex) |
0c73f18b | 43 | */ |
41fc1c27 | 44 | static void sysfs_link_sibling(struct sysfs_dirent *sd) |
0c73f18b TH |
45 | { |
46 | struct sysfs_dirent *parent_sd = sd->s_parent; | |
3efa65b9 | 47 | struct sysfs_dirent **pos; |
0c73f18b TH |
48 | |
49 | BUG_ON(sd->s_sibling); | |
3efa65b9 EB |
50 | |
51 | /* Store directory entries in order by ino. This allows | |
52 | * readdir to properly restart without having to add a | |
bc747f37 | 53 | * cursor into the s_dir.children list. |
3efa65b9 | 54 | */ |
bc747f37 | 55 | for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) { |
3efa65b9 EB |
56 | if (sd->s_ino < (*pos)->s_ino) |
57 | break; | |
58 | } | |
59 | sd->s_sibling = *pos; | |
60 | *pos = sd; | |
0c73f18b TH |
61 | } |
62 | ||
63 | /** | |
64 | * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list | |
65 | * @sd: sysfs_dirent of interest | |
66 | * | |
67 | * Unlink @sd from its sibling list which starts from | |
bc747f37 | 68 | * sd->s_parent->s_dir.children. |
0c73f18b TH |
69 | * |
70 | * Locking: | |
3007e997 | 71 | * mutex_lock(sysfs_mutex) |
0c73f18b | 72 | */ |
41fc1c27 | 73 | static void sysfs_unlink_sibling(struct sysfs_dirent *sd) |
0c73f18b TH |
74 | { |
75 | struct sysfs_dirent **pos; | |
76 | ||
bc747f37 TH |
77 | for (pos = &sd->s_parent->s_dir.children; *pos; |
78 | pos = &(*pos)->s_sibling) { | |
0c73f18b TH |
79 | if (*pos == sd) { |
80 | *pos = sd->s_sibling; | |
81 | sd->s_sibling = NULL; | |
82 | break; | |
83 | } | |
84 | } | |
85 | } | |
86 | ||
53e0ae92 TH |
87 | /** |
88 | * sysfs_get_dentry - get dentry for the given sysfs_dirent | |
89 | * @sd: sysfs_dirent of interest | |
90 | * | |
91 | * Get dentry for @sd. Dentry is looked up if currently not | |
e0712bbf TH |
92 | * present. This function descends from the root looking up |
93 | * dentry for each step. | |
53e0ae92 TH |
94 | * |
95 | * LOCKING: | |
932ea2e3 | 96 | * mutex_lock(sysfs_rename_mutex) |
53e0ae92 TH |
97 | * |
98 | * RETURNS: | |
99 | * Pointer to found dentry on success, ERR_PTR() value on error. | |
100 | */ | |
101 | struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd) | |
102 | { | |
e0712bbf | 103 | struct dentry *dentry = dget(sysfs_sb->s_root); |
53e0ae92 | 104 | |
e0712bbf TH |
105 | while (dentry->d_fsdata != sd) { |
106 | struct sysfs_dirent *cur; | |
107 | struct dentry *parent; | |
53e0ae92 | 108 | |
e0712bbf TH |
109 | /* find the first ancestor which hasn't been looked up */ |
110 | cur = sd; | |
111 | while (cur->s_parent != dentry->d_fsdata) | |
53e0ae92 TH |
112 | cur = cur->s_parent; |
113 | ||
53e0ae92 | 114 | /* look it up */ |
e0712bbf TH |
115 | parent = dentry; |
116 | mutex_lock(&parent->d_inode->i_mutex); | |
eead1911 | 117 | dentry = lookup_one_noperm(cur->s_name, parent); |
e0712bbf TH |
118 | mutex_unlock(&parent->d_inode->i_mutex); |
119 | dput(parent); | |
53e0ae92 | 120 | |
e0712bbf TH |
121 | if (IS_ERR(dentry)) |
122 | break; | |
53e0ae92 | 123 | } |
53e0ae92 TH |
124 | return dentry; |
125 | } | |
126 | ||
b6b4a439 TH |
127 | /** |
128 | * sysfs_get_active - get an active reference to sysfs_dirent | |
129 | * @sd: sysfs_dirent to get an active reference to | |
130 | * | |
131 | * Get an active reference of @sd. This function is noop if @sd | |
132 | * is NULL. | |
133 | * | |
134 | * RETURNS: | |
135 | * Pointer to @sd on success, NULL on failure. | |
136 | */ | |
78e9d367 | 137 | static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) |
b6b4a439 | 138 | { |
8619f979 TH |
139 | if (unlikely(!sd)) |
140 | return NULL; | |
141 | ||
142 | while (1) { | |
143 | int v, t; | |
144 | ||
145 | v = atomic_read(&sd->s_active); | |
146 | if (unlikely(v < 0)) | |
147 | return NULL; | |
148 | ||
149 | t = atomic_cmpxchg(&sd->s_active, v, v + 1); | |
150 | if (likely(t == v)) | |
151 | return sd; | |
152 | if (t < 0) | |
153 | return NULL; | |
154 | ||
155 | cpu_relax(); | |
b6b4a439 | 156 | } |
b6b4a439 TH |
157 | } |
158 | ||
159 | /** | |
160 | * sysfs_put_active - put an active reference to sysfs_dirent | |
161 | * @sd: sysfs_dirent to put an active reference to | |
162 | * | |
163 | * Put an active reference to @sd. This function is noop if @sd | |
164 | * is NULL. | |
165 | */ | |
78e9d367 | 166 | static void sysfs_put_active(struct sysfs_dirent *sd) |
b6b4a439 | 167 | { |
8619f979 TH |
168 | struct completion *cmpl; |
169 | int v; | |
170 | ||
171 | if (unlikely(!sd)) | |
172 | return; | |
173 | ||
174 | v = atomic_dec_return(&sd->s_active); | |
175 | if (likely(v != SD_DEACTIVATED_BIAS)) | |
176 | return; | |
177 | ||
178 | /* atomic_dec_return() is a mb(), we'll always see the updated | |
0c73f18b | 179 | * sd->s_sibling. |
8619f979 | 180 | */ |
0c73f18b | 181 | cmpl = (void *)sd->s_sibling; |
8619f979 | 182 | complete(cmpl); |
b6b4a439 TH |
183 | } |
184 | ||
185 | /** | |
186 | * sysfs_get_active_two - get active references to sysfs_dirent and parent | |
187 | * @sd: sysfs_dirent of interest | |
188 | * | |
189 | * Get active reference to @sd and its parent. Parent's active | |
190 | * reference is grabbed first. This function is noop if @sd is | |
191 | * NULL. | |
192 | * | |
193 | * RETURNS: | |
194 | * Pointer to @sd on success, NULL on failure. | |
195 | */ | |
196 | struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd) | |
197 | { | |
198 | if (sd) { | |
199 | if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent))) | |
200 | return NULL; | |
201 | if (unlikely(!sysfs_get_active(sd))) { | |
202 | sysfs_put_active(sd->s_parent); | |
203 | return NULL; | |
204 | } | |
205 | } | |
206 | return sd; | |
207 | } | |
208 | ||
209 | /** | |
210 | * sysfs_put_active_two - put active references to sysfs_dirent and parent | |
211 | * @sd: sysfs_dirent of interest | |
212 | * | |
213 | * Put active references to @sd and its parent. This function is | |
214 | * noop if @sd is NULL. | |
215 | */ | |
216 | void sysfs_put_active_two(struct sysfs_dirent *sd) | |
217 | { | |
218 | if (sd) { | |
219 | sysfs_put_active(sd); | |
220 | sysfs_put_active(sd->s_parent); | |
221 | } | |
222 | } | |
223 | ||
224 | /** | |
225 | * sysfs_deactivate - deactivate sysfs_dirent | |
226 | * @sd: sysfs_dirent to deactivate | |
227 | * | |
8619f979 | 228 | * Deny new active references and drain existing ones. |
b6b4a439 | 229 | */ |
fb6896da | 230 | static void sysfs_deactivate(struct sysfs_dirent *sd) |
b6b4a439 | 231 | { |
8619f979 TH |
232 | DECLARE_COMPLETION_ONSTACK(wait); |
233 | int v; | |
b6b4a439 | 234 | |
380e6fbb | 235 | BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED)); |
0c73f18b | 236 | sd->s_sibling = (void *)&wait; |
8619f979 TH |
237 | |
238 | /* atomic_add_return() is a mb(), put_active() will always see | |
0c73f18b | 239 | * the updated sd->s_sibling. |
b6b4a439 | 240 | */ |
8619f979 TH |
241 | v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); |
242 | ||
243 | if (v != SD_DEACTIVATED_BIAS) | |
244 | wait_for_completion(&wait); | |
245 | ||
0c73f18b | 246 | sd->s_sibling = NULL; |
b6b4a439 TH |
247 | } |
248 | ||
42b37df6 | 249 | static int sysfs_alloc_ino(ino_t *pino) |
2b611bb7 TH |
250 | { |
251 | int ino, rc; | |
252 | ||
253 | retry: | |
254 | spin_lock(&sysfs_ino_lock); | |
255 | rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino); | |
256 | spin_unlock(&sysfs_ino_lock); | |
257 | ||
258 | if (rc == -EAGAIN) { | |
259 | if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL)) | |
260 | goto retry; | |
261 | rc = -ENOMEM; | |
262 | } | |
263 | ||
264 | *pino = ino; | |
265 | return rc; | |
266 | } | |
267 | ||
268 | static void sysfs_free_ino(ino_t ino) | |
269 | { | |
270 | spin_lock(&sysfs_ino_lock); | |
271 | ida_remove(&sysfs_ino_ida, ino); | |
272 | spin_unlock(&sysfs_ino_lock); | |
273 | } | |
274 | ||
fa7f912a TH |
275 | void release_sysfs_dirent(struct sysfs_dirent * sd) |
276 | { | |
13b3086d TH |
277 | struct sysfs_dirent *parent_sd; |
278 | ||
279 | repeat: | |
3007e997 TH |
280 | /* Moving/renaming is always done while holding reference. |
281 | * sd->s_parent won't change beneath us. | |
282 | */ | |
13b3086d TH |
283 | parent_sd = sd->s_parent; |
284 | ||
b402d72c | 285 | if (sysfs_type(sd) == SYSFS_KOBJ_LINK) |
b1fc3d61 | 286 | sysfs_put(sd->s_symlink.target_sd); |
b402d72c | 287 | if (sysfs_type(sd) & SYSFS_COPY_NAME) |
0c096b50 | 288 | kfree(sd->s_name); |
4c3da220 EB |
289 | if (sd->s_iattr && sd->s_iattr->ia_secdata) |
290 | security_release_secctx(sd->s_iattr->ia_secdata, | |
291 | sd->s_iattr->ia_secdata_len); | |
fa7f912a | 292 | kfree(sd->s_iattr); |
2b611bb7 | 293 | sysfs_free_ino(sd->s_ino); |
fa7f912a | 294 | kmem_cache_free(sysfs_dir_cachep, sd); |
13b3086d TH |
295 | |
296 | sd = parent_sd; | |
297 | if (sd && atomic_dec_and_test(&sd->s_count)) | |
298 | goto repeat; | |
fa7f912a TH |
299 | } |
300 | ||
e8f077c8 EB |
301 | static int sysfs_dentry_delete(struct dentry *dentry) |
302 | { | |
303 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
304 | return !!(sd->s_flags & SYSFS_FLAG_REMOVED); | |
305 | } | |
306 | ||
307 | static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) | |
308 | { | |
309 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
310 | int is_dir; | |
311 | ||
312 | mutex_lock(&sysfs_mutex); | |
313 | ||
314 | /* The sysfs dirent has been deleted */ | |
315 | if (sd->s_flags & SYSFS_FLAG_REMOVED) | |
316 | goto out_bad; | |
317 | ||
318 | mutex_unlock(&sysfs_mutex); | |
319 | out_valid: | |
320 | return 1; | |
321 | out_bad: | |
322 | /* Remove the dentry from the dcache hashes. | |
323 | * If this is a deleted dentry we use d_drop instead of d_delete | |
324 | * so sysfs doesn't need to cope with negative dentries. | |
325 | */ | |
326 | is_dir = (sysfs_type(sd) == SYSFS_DIR); | |
327 | mutex_unlock(&sysfs_mutex); | |
328 | if (is_dir) { | |
329 | /* If we have submounts we must allow the vfs caches | |
330 | * to lie about the state of the filesystem to prevent | |
331 | * leaks and other nasty things. | |
332 | */ | |
333 | if (have_submounts(dentry)) | |
334 | goto out_valid; | |
335 | shrink_dcache_parent(dentry); | |
336 | } | |
337 | d_drop(dentry); | |
338 | return 0; | |
339 | } | |
340 | ||
28a027cf | 341 | static void sysfs_dentry_iput(struct dentry *dentry, struct inode *inode) |
1da177e4 LT |
342 | { |
343 | struct sysfs_dirent * sd = dentry->d_fsdata; | |
344 | ||
5a26b79c | 345 | sysfs_put(sd); |
1da177e4 LT |
346 | iput(inode); |
347 | } | |
348 | ||
ee1ec329 | 349 | static const struct dentry_operations sysfs_dentry_ops = { |
e8f077c8 EB |
350 | .d_revalidate = sysfs_dentry_revalidate, |
351 | .d_delete = sysfs_dentry_delete, | |
28a027cf | 352 | .d_iput = sysfs_dentry_iput, |
1da177e4 LT |
353 | }; |
354 | ||
3e519038 | 355 | struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) |
1da177e4 | 356 | { |
0c096b50 | 357 | char *dup_name = NULL; |
01da2425 | 358 | struct sysfs_dirent *sd; |
0c096b50 TH |
359 | |
360 | if (type & SYSFS_COPY_NAME) { | |
361 | name = dup_name = kstrdup(name, GFP_KERNEL); | |
362 | if (!name) | |
01da2425 | 363 | return NULL; |
0c096b50 | 364 | } |
1da177e4 | 365 | |
c3762229 | 366 | sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); |
1da177e4 | 367 | if (!sd) |
01da2425 | 368 | goto err_out1; |
1da177e4 | 369 | |
0c096b50 | 370 | if (sysfs_alloc_ino(&sd->s_ino)) |
01da2425 | 371 | goto err_out2; |
2b611bb7 | 372 | |
1da177e4 | 373 | atomic_set(&sd->s_count, 1); |
8619f979 | 374 | atomic_set(&sd->s_active, 0); |
a26cd722 | 375 | |
0c096b50 | 376 | sd->s_name = name; |
a26cd722 | 377 | sd->s_mode = mode; |
b402d72c | 378 | sd->s_flags = type; |
1da177e4 LT |
379 | |
380 | return sd; | |
0c096b50 | 381 | |
01da2425 | 382 | err_out2: |
0c096b50 | 383 | kmem_cache_free(sysfs_dir_cachep, sd); |
01da2425 AM |
384 | err_out1: |
385 | kfree(dup_name); | |
0c096b50 | 386 | return NULL; |
1da177e4 LT |
387 | } |
388 | ||
fb6896da TH |
389 | static int sysfs_ilookup_test(struct inode *inode, void *arg) |
390 | { | |
391 | struct sysfs_dirent *sd = arg; | |
392 | return inode->i_ino == sd->s_ino; | |
393 | } | |
394 | ||
3007e997 | 395 | /** |
fb6896da TH |
396 | * sysfs_addrm_start - prepare for sysfs_dirent add/remove |
397 | * @acxt: pointer to sysfs_addrm_cxt to be used | |
398 | * @parent_sd: parent sysfs_dirent | |
3007e997 | 399 | * |
fb6896da TH |
400 | * This function is called when the caller is about to add or |
401 | * remove sysfs_dirent under @parent_sd. This function acquires | |
402 | * sysfs_mutex, grabs inode for @parent_sd if available and lock | |
403 | * i_mutex of it. @acxt is used to keep and pass context to | |
404 | * other addrm functions. | |
3007e997 TH |
405 | * |
406 | * LOCKING: | |
fb6896da TH |
407 | * Kernel thread context (may sleep). sysfs_mutex is locked on |
408 | * return. i_mutex of parent inode is locked on return if | |
409 | * available. | |
3007e997 | 410 | */ |
fb6896da TH |
411 | void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, |
412 | struct sysfs_dirent *parent_sd) | |
b592fcfe | 413 | { |
fb6896da | 414 | struct inode *inode; |
b592fcfe | 415 | |
fb6896da TH |
416 | memset(acxt, 0, sizeof(*acxt)); |
417 | acxt->parent_sd = parent_sd; | |
418 | ||
45c076c5 TH |
419 | /* Lookup parent inode. inode initialization is protected by |
420 | * sysfs_mutex, so inode existence can be determined by | |
421 | * looking up inode while holding sysfs_mutex. | |
fb6896da TH |
422 | */ |
423 | mutex_lock(&sysfs_mutex); | |
424 | ||
45c076c5 TH |
425 | inode = ilookup5(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test, |
426 | parent_sd); | |
427 | if (inode) { | |
428 | WARN_ON(inode->i_state & I_NEW); | |
fb6896da | 429 | |
fb6896da TH |
430 | /* parent inode available */ |
431 | acxt->parent_inode = inode; | |
432 | ||
433 | /* sysfs_mutex is below i_mutex in lock hierarchy. | |
434 | * First, trylock i_mutex. If fails, unlock | |
435 | * sysfs_mutex and lock them in order. | |
436 | */ | |
437 | if (!mutex_trylock(&inode->i_mutex)) { | |
438 | mutex_unlock(&sysfs_mutex); | |
439 | mutex_lock(&inode->i_mutex); | |
440 | mutex_lock(&sysfs_mutex); | |
441 | } | |
45c076c5 | 442 | } |
fb6896da TH |
443 | } |
444 | ||
445 | /** | |
36ce6dad | 446 | * __sysfs_add_one - add sysfs_dirent to parent without warning |
fb6896da TH |
447 | * @acxt: addrm context to use |
448 | * @sd: sysfs_dirent to be added | |
449 | * | |
450 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
181b2e4b TH |
451 | * nlink of parent inode if @sd is a directory and link into the |
452 | * children list of the parent. | |
fb6896da TH |
453 | * |
454 | * This function should be called between calls to | |
455 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
456 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
457 | * | |
458 | * LOCKING: | |
459 | * Determined by sysfs_addrm_start(). | |
23dc2799 TH |
460 | * |
461 | * RETURNS: | |
462 | * 0 on success, -EEXIST if entry with the given name already | |
463 | * exists. | |
fb6896da | 464 | */ |
36ce6dad | 465 | int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) |
fb6896da | 466 | { |
0599ad53 | 467 | if (sysfs_find_dirent(acxt->parent_sd, sd->s_name)) |
23dc2799 TH |
468 | return -EEXIST; |
469 | ||
fb6896da TH |
470 | sd->s_parent = sysfs_get(acxt->parent_sd); |
471 | ||
472 | if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) | |
473 | inc_nlink(acxt->parent_inode); | |
474 | ||
475 | acxt->cnt++; | |
41fc1c27 TH |
476 | |
477 | sysfs_link_sibling(sd); | |
23dc2799 TH |
478 | |
479 | return 0; | |
fb6896da TH |
480 | } |
481 | ||
425cb029 AC |
482 | /** |
483 | * sysfs_pathname - return full path to sysfs dirent | |
484 | * @sd: sysfs_dirent whose path we want | |
485 | * @path: caller allocated buffer | |
486 | * | |
487 | * Gives the name "/" to the sysfs_root entry; any path returned | |
488 | * is relative to wherever sysfs is mounted. | |
489 | * | |
490 | * XXX: does no error checking on @path size | |
491 | */ | |
492 | static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) | |
493 | { | |
494 | if (sd->s_parent) { | |
495 | sysfs_pathname(sd->s_parent, path); | |
496 | strcat(path, "/"); | |
497 | } | |
498 | strcat(path, sd->s_name); | |
499 | return path; | |
500 | } | |
501 | ||
36ce6dad CH |
502 | /** |
503 | * sysfs_add_one - add sysfs_dirent to parent | |
504 | * @acxt: addrm context to use | |
505 | * @sd: sysfs_dirent to be added | |
506 | * | |
507 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
508 | * nlink of parent inode if @sd is a directory and link into the | |
509 | * children list of the parent. | |
510 | * | |
511 | * This function should be called between calls to | |
512 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
513 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
514 | * | |
515 | * LOCKING: | |
516 | * Determined by sysfs_addrm_start(). | |
517 | * | |
518 | * RETURNS: | |
519 | * 0 on success, -EEXIST if entry with the given name already | |
520 | * exists. | |
521 | */ | |
522 | int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
523 | { | |
524 | int ret; | |
525 | ||
526 | ret = __sysfs_add_one(acxt, sd); | |
425cb029 AC |
527 | if (ret == -EEXIST) { |
528 | char *path = kzalloc(PATH_MAX, GFP_KERNEL); | |
529 | WARN(1, KERN_WARNING | |
530 | "sysfs: cannot create duplicate filename '%s'\n", | |
531 | (path == NULL) ? sd->s_name : | |
532 | strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"), | |
533 | sd->s_name)); | |
534 | kfree(path); | |
535 | } | |
536 | ||
36ce6dad CH |
537 | return ret; |
538 | } | |
539 | ||
fb6896da TH |
540 | /** |
541 | * sysfs_remove_one - remove sysfs_dirent from parent | |
542 | * @acxt: addrm context to use | |
9fd5b1c9 | 543 | * @sd: sysfs_dirent to be removed |
fb6896da TH |
544 | * |
545 | * Mark @sd removed and drop nlink of parent inode if @sd is a | |
181b2e4b | 546 | * directory. @sd is unlinked from the children list. |
fb6896da TH |
547 | * |
548 | * This function should be called between calls to | |
549 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
550 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
551 | * | |
552 | * LOCKING: | |
553 | * Determined by sysfs_addrm_start(). | |
554 | */ | |
555 | void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
556 | { | |
41fc1c27 TH |
557 | BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED); |
558 | ||
559 | sysfs_unlink_sibling(sd); | |
fb6896da TH |
560 | |
561 | sd->s_flags |= SYSFS_FLAG_REMOVED; | |
562 | sd->s_sibling = acxt->removed; | |
563 | acxt->removed = sd; | |
564 | ||
565 | if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) | |
566 | drop_nlink(acxt->parent_inode); | |
567 | ||
568 | acxt->cnt++; | |
569 | } | |
570 | ||
a0edd7c8 | 571 | /** |
e8f077c8 | 572 | * sysfs_dec_nlink - Decrement link count for the specified sysfs_dirent |
a0edd7c8 TH |
573 | * @sd: target sysfs_dirent |
574 | * | |
e8f077c8 | 575 | * Decrement nlink for @sd. @sd must have been unlinked from its |
a0edd7c8 TH |
576 | * parent on entry to this function such that it can't be looked |
577 | * up anymore. | |
a0edd7c8 | 578 | */ |
e8f077c8 | 579 | static void sysfs_dec_nlink(struct sysfs_dirent *sd) |
a0edd7c8 | 580 | { |
a0edd7c8 | 581 | struct inode *inode; |
89bec097 EB |
582 | |
583 | inode = ilookup(sysfs_sb, sd->s_ino); | |
584 | if (!inode) | |
585 | return; | |
a0edd7c8 | 586 | |
a0edd7c8 | 587 | /* adjust nlink and update timestamp */ |
89bec097 | 588 | mutex_lock(&inode->i_mutex); |
a0edd7c8 | 589 | |
89bec097 EB |
590 | inode->i_ctime = CURRENT_TIME; |
591 | drop_nlink(inode); | |
592 | if (sysfs_type(sd) == SYSFS_DIR) | |
a0edd7c8 | 593 | drop_nlink(inode); |
a0edd7c8 | 594 | |
89bec097 EB |
595 | mutex_unlock(&inode->i_mutex); |
596 | ||
597 | iput(inode); | |
a0edd7c8 TH |
598 | } |
599 | ||
fb6896da TH |
600 | /** |
601 | * sysfs_addrm_finish - finish up sysfs_dirent add/remove | |
602 | * @acxt: addrm context to finish up | |
603 | * | |
604 | * Finish up sysfs_dirent add/remove. Resources acquired by | |
605 | * sysfs_addrm_start() are released and removed sysfs_dirents are | |
606 | * cleaned up. Timestamps on the parent inode are updated. | |
607 | * | |
608 | * LOCKING: | |
609 | * All mutexes acquired by sysfs_addrm_start() are released. | |
fb6896da | 610 | */ |
990e53f8 | 611 | void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) |
fb6896da TH |
612 | { |
613 | /* release resources acquired by sysfs_addrm_start() */ | |
614 | mutex_unlock(&sysfs_mutex); | |
615 | if (acxt->parent_inode) { | |
616 | struct inode *inode = acxt->parent_inode; | |
617 | ||
618 | /* if added/removed, update timestamps on the parent */ | |
619 | if (acxt->cnt) | |
620 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; | |
621 | ||
622 | mutex_unlock(&inode->i_mutex); | |
623 | iput(inode); | |
624 | } | |
625 | ||
626 | /* kill removed sysfs_dirents */ | |
627 | while (acxt->removed) { | |
628 | struct sysfs_dirent *sd = acxt->removed; | |
629 | ||
630 | acxt->removed = sd->s_sibling; | |
631 | sd->s_sibling = NULL; | |
632 | ||
e8f077c8 | 633 | sysfs_dec_nlink(sd); |
fb6896da | 634 | sysfs_deactivate(sd); |
e0edd3c6 | 635 | unmap_bin_file(sd); |
fb6896da | 636 | sysfs_put(sd); |
13b3086d | 637 | } |
b592fcfe EB |
638 | } |
639 | ||
f0b0af47 TH |
640 | /** |
641 | * sysfs_find_dirent - find sysfs_dirent with the given name | |
642 | * @parent_sd: sysfs_dirent to search under | |
643 | * @name: name to look for | |
644 | * | |
645 | * Look for sysfs_dirent with name @name under @parent_sd. | |
c516865c | 646 | * |
f0b0af47 | 647 | * LOCKING: |
3007e997 | 648 | * mutex_lock(sysfs_mutex) |
c516865c | 649 | * |
f0b0af47 TH |
650 | * RETURNS: |
651 | * Pointer to sysfs_dirent if found, NULL if not. | |
c516865c | 652 | */ |
f0b0af47 TH |
653 | struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, |
654 | const unsigned char *name) | |
c516865c | 655 | { |
f0b0af47 TH |
656 | struct sysfs_dirent *sd; |
657 | ||
bc747f37 | 658 | for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) |
3efa65b9 | 659 | if (!strcmp(sd->s_name, name)) |
f0b0af47 TH |
660 | return sd; |
661 | return NULL; | |
662 | } | |
c516865c | 663 | |
f0b0af47 TH |
664 | /** |
665 | * sysfs_get_dirent - find and get sysfs_dirent with the given name | |
666 | * @parent_sd: sysfs_dirent to search under | |
667 | * @name: name to look for | |
668 | * | |
669 | * Look for sysfs_dirent with name @name under @parent_sd and get | |
670 | * it if found. | |
671 | * | |
672 | * LOCKING: | |
3007e997 | 673 | * Kernel thread context (may sleep). Grabs sysfs_mutex. |
f0b0af47 TH |
674 | * |
675 | * RETURNS: | |
676 | * Pointer to sysfs_dirent if found, NULL if not. | |
677 | */ | |
678 | struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, | |
679 | const unsigned char *name) | |
680 | { | |
681 | struct sysfs_dirent *sd; | |
682 | ||
3007e997 | 683 | mutex_lock(&sysfs_mutex); |
f0b0af47 TH |
684 | sd = sysfs_find_dirent(parent_sd, name); |
685 | sysfs_get(sd); | |
3007e997 | 686 | mutex_unlock(&sysfs_mutex); |
f0b0af47 TH |
687 | |
688 | return sd; | |
c516865c | 689 | } |
f1282c84 | 690 | EXPORT_SYMBOL_GPL(sysfs_get_dirent); |
c516865c | 691 | |
608e266a TH |
692 | static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, |
693 | const char *name, struct sysfs_dirent **p_sd) | |
1da177e4 | 694 | { |
1da177e4 | 695 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; |
51225039 | 696 | struct sysfs_addrm_cxt acxt; |
dfeb9fb0 | 697 | struct sysfs_dirent *sd; |
23dc2799 | 698 | int rc; |
1da177e4 | 699 | |
fc9f54b9 | 700 | /* allocate */ |
3e519038 | 701 | sd = sysfs_new_dirent(name, mode, SYSFS_DIR); |
a26cd722 | 702 | if (!sd) |
51225039 | 703 | return -ENOMEM; |
b1fc3d61 | 704 | sd->s_dir.kobj = kobj; |
dfeb9fb0 | 705 | |
fc9f54b9 | 706 | /* link in */ |
51225039 | 707 | sysfs_addrm_start(&acxt, parent_sd); |
23dc2799 TH |
708 | rc = sysfs_add_one(&acxt, sd); |
709 | sysfs_addrm_finish(&acxt); | |
967e35dc | 710 | |
23dc2799 TH |
711 | if (rc == 0) |
712 | *p_sd = sd; | |
713 | else | |
967e35dc | 714 | sysfs_put(sd); |
dfeb9fb0 | 715 | |
23dc2799 | 716 | return rc; |
1da177e4 LT |
717 | } |
718 | ||
608e266a TH |
719 | int sysfs_create_subdir(struct kobject *kobj, const char *name, |
720 | struct sysfs_dirent **p_sd) | |
1da177e4 | 721 | { |
608e266a | 722 | return create_dir(kobj, kobj->sd, name, p_sd); |
1da177e4 LT |
723 | } |
724 | ||
725 | /** | |
726 | * sysfs_create_dir - create a directory for an object. | |
1da177e4 LT |
727 | * @kobj: object we're creating directory for. |
728 | */ | |
90bc6135 | 729 | int sysfs_create_dir(struct kobject * kobj) |
1da177e4 | 730 | { |
608e266a | 731 | struct sysfs_dirent *parent_sd, *sd; |
1da177e4 LT |
732 | int error = 0; |
733 | ||
734 | BUG_ON(!kobj); | |
735 | ||
90bc6135 | 736 | if (kobj->parent) |
608e266a | 737 | parent_sd = kobj->parent->sd; |
1da177e4 | 738 | else |
7d0c7d67 | 739 | parent_sd = &sysfs_root; |
1da177e4 | 740 | |
608e266a | 741 | error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd); |
1da177e4 | 742 | if (!error) |
608e266a | 743 | kobj->sd = sd; |
1da177e4 LT |
744 | return error; |
745 | } | |
746 | ||
1da177e4 LT |
747 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, |
748 | struct nameidata *nd) | |
749 | { | |
6cb52147 | 750 | struct dentry *ret = NULL; |
a7a04754 TH |
751 | struct sysfs_dirent *parent_sd = dentry->d_parent->d_fsdata; |
752 | struct sysfs_dirent *sd; | |
fc9f54b9 | 753 | struct inode *inode; |
1da177e4 | 754 | |
6cb52147 TH |
755 | mutex_lock(&sysfs_mutex); |
756 | ||
94777e09 | 757 | sd = sysfs_find_dirent(parent_sd, dentry->d_name.name); |
1da177e4 | 758 | |
fc9f54b9 | 759 | /* no such entry */ |
e49452c6 TH |
760 | if (!sd) { |
761 | ret = ERR_PTR(-ENOENT); | |
6cb52147 | 762 | goto out_unlock; |
e49452c6 | 763 | } |
fc9f54b9 TH |
764 | |
765 | /* attach dentry and inode */ | |
8312a8d7 | 766 | inode = sysfs_get_inode(sd); |
6cb52147 TH |
767 | if (!inode) { |
768 | ret = ERR_PTR(-ENOMEM); | |
769 | goto out_unlock; | |
770 | } | |
3007e997 | 771 | |
d6b4fd2f TH |
772 | /* instantiate and hash dentry */ |
773 | dentry->d_op = &sysfs_dentry_ops; | |
774 | dentry->d_fsdata = sysfs_get(sd); | |
119dd52b | 775 | d_instantiate(dentry, inode); |
d6b4fd2f | 776 | d_rehash(dentry); |
fc9f54b9 | 777 | |
6cb52147 | 778 | out_unlock: |
3007e997 | 779 | mutex_unlock(&sysfs_mutex); |
6cb52147 | 780 | return ret; |
1da177e4 LT |
781 | } |
782 | ||
c5ef1c42 | 783 | const struct inode_operations sysfs_dir_inode_operations = { |
1da177e4 | 784 | .lookup = sysfs_lookup, |
988d186d | 785 | .setattr = sysfs_setattr, |
ddd29ec6 | 786 | .setxattr = sysfs_setxattr, |
1da177e4 LT |
787 | }; |
788 | ||
608e266a | 789 | static void remove_dir(struct sysfs_dirent *sd) |
1da177e4 | 790 | { |
fb6896da | 791 | struct sysfs_addrm_cxt acxt; |
1da177e4 | 792 | |
fb6896da | 793 | sysfs_addrm_start(&acxt, sd->s_parent); |
fb6896da TH |
794 | sysfs_remove_one(&acxt, sd); |
795 | sysfs_addrm_finish(&acxt); | |
1da177e4 LT |
796 | } |
797 | ||
608e266a | 798 | void sysfs_remove_subdir(struct sysfs_dirent *sd) |
1da177e4 | 799 | { |
608e266a | 800 | remove_dir(sd); |
1da177e4 LT |
801 | } |
802 | ||
803 | ||
608e266a | 804 | static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) |
1da177e4 | 805 | { |
fb6896da | 806 | struct sysfs_addrm_cxt acxt; |
0c73f18b | 807 | struct sysfs_dirent **pos; |
1da177e4 | 808 | |
608e266a | 809 | if (!dir_sd) |
1da177e4 LT |
810 | return; |
811 | ||
608e266a | 812 | pr_debug("sysfs %s: removing dir\n", dir_sd->s_name); |
fb6896da | 813 | sysfs_addrm_start(&acxt, dir_sd); |
bc747f37 | 814 | pos = &dir_sd->s_dir.children; |
0c73f18b TH |
815 | while (*pos) { |
816 | struct sysfs_dirent *sd = *pos; | |
817 | ||
3efa65b9 | 818 | if (sysfs_type(sd) != SYSFS_DIR) |
fb6896da | 819 | sysfs_remove_one(&acxt, sd); |
41fc1c27 | 820 | else |
0c73f18b | 821 | pos = &(*pos)->s_sibling; |
1da177e4 | 822 | } |
fb6896da | 823 | sysfs_addrm_finish(&acxt); |
0ab66088 | 824 | |
608e266a | 825 | remove_dir(dir_sd); |
b592fcfe EB |
826 | } |
827 | ||
828 | /** | |
829 | * sysfs_remove_dir - remove an object's directory. | |
830 | * @kobj: object. | |
831 | * | |
832 | * The only thing special about this is that we remove any files in | |
833 | * the directory before we remove the directory, and we've inlined | |
834 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
835 | */ | |
836 | ||
837 | void sysfs_remove_dir(struct kobject * kobj) | |
838 | { | |
608e266a | 839 | struct sysfs_dirent *sd = kobj->sd; |
aecdceda | 840 | |
5f995323 | 841 | spin_lock(&sysfs_assoc_lock); |
608e266a | 842 | kobj->sd = NULL; |
5f995323 | 843 | spin_unlock(&sysfs_assoc_lock); |
aecdceda | 844 | |
608e266a | 845 | __sysfs_remove_dir(sd); |
1da177e4 LT |
846 | } |
847 | ||
90bc6135 | 848 | int sysfs_rename_dir(struct kobject * kobj, const char *new_name) |
1da177e4 | 849 | { |
9918f9a4 | 850 | struct sysfs_dirent *sd = kobj->sd; |
90bc6135 | 851 | struct dentry *parent = NULL; |
51225039 TH |
852 | struct dentry *old_dentry = NULL, *new_dentry = NULL; |
853 | const char *dup_name = NULL; | |
996b7376 | 854 | int error; |
1da177e4 | 855 | |
932ea2e3 EB |
856 | mutex_lock(&sysfs_rename_mutex); |
857 | ||
9918f9a4 EB |
858 | error = 0; |
859 | if (strcmp(sd->s_name, new_name) == 0) | |
860 | goto out; /* nothing to rename */ | |
861 | ||
ff869de7 | 862 | /* get the original dentry */ |
51225039 TH |
863 | old_dentry = sysfs_get_dentry(sd); |
864 | if (IS_ERR(old_dentry)) { | |
865 | error = PTR_ERR(old_dentry); | |
456ef155 | 866 | old_dentry = NULL; |
9918f9a4 | 867 | goto out; |
51225039 TH |
868 | } |
869 | ||
ff869de7 | 870 | parent = old_dentry->d_parent; |
1da177e4 | 871 | |
90bc6135 EB |
872 | /* lock parent and get dentry for new name */ |
873 | mutex_lock(&parent->d_inode->i_mutex); | |
9918f9a4 | 874 | mutex_lock(&sysfs_mutex); |
1da177e4 | 875 | |
9918f9a4 EB |
876 | error = -EEXIST; |
877 | if (sysfs_find_dirent(sd->s_parent, new_name)) | |
51225039 | 878 | goto out_unlock; |
996b7376 | 879 | |
9918f9a4 EB |
880 | error = -ENOMEM; |
881 | new_dentry = d_alloc_name(parent, new_name); | |
882 | if (!new_dentry) | |
51225039 | 883 | goto out_unlock; |
996b7376 | 884 | |
0b4a4fea | 885 | /* rename sysfs_dirent */ |
0c096b50 TH |
886 | error = -ENOMEM; |
887 | new_name = dup_name = kstrdup(new_name, GFP_KERNEL); | |
888 | if (!new_name) | |
9918f9a4 | 889 | goto out_unlock; |
0c096b50 | 890 | |
51225039 | 891 | dup_name = sd->s_name; |
0c096b50 TH |
892 | sd->s_name = new_name; |
893 | ||
ff869de7 | 894 | /* rename */ |
996b7376 | 895 | d_add(new_dentry, NULL); |
5a26b79c | 896 | d_move(old_dentry, new_dentry); |
996b7376 | 897 | |
996b7376 | 898 | error = 0; |
996b7376 | 899 | out_unlock: |
9918f9a4 | 900 | mutex_unlock(&sysfs_mutex); |
90bc6135 | 901 | mutex_unlock(&parent->d_inode->i_mutex); |
51225039 | 902 | kfree(dup_name); |
51225039 TH |
903 | dput(old_dentry); |
904 | dput(new_dentry); | |
9918f9a4 | 905 | out: |
932ea2e3 | 906 | mutex_unlock(&sysfs_rename_mutex); |
1da177e4 LT |
907 | return error; |
908 | } | |
909 | ||
51225039 | 910 | int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) |
8a82472f | 911 | { |
51225039 TH |
912 | struct sysfs_dirent *sd = kobj->sd; |
913 | struct sysfs_dirent *new_parent_sd; | |
914 | struct dentry *old_parent, *new_parent = NULL; | |
915 | struct dentry *old_dentry = NULL, *new_dentry = NULL; | |
8a82472f CH |
916 | int error; |
917 | ||
932ea2e3 | 918 | mutex_lock(&sysfs_rename_mutex); |
51225039 | 919 | BUG_ON(!sd->s_parent); |
a6a83577 CH |
920 | new_parent_sd = (new_parent_kobj && new_parent_kobj->sd) ? |
921 | new_parent_kobj->sd : &sysfs_root; | |
51225039 | 922 | |
45aaae9c EB |
923 | error = 0; |
924 | if (sd->s_parent == new_parent_sd) | |
925 | goto out; /* nothing to move */ | |
926 | ||
51225039 TH |
927 | /* get dentries */ |
928 | old_dentry = sysfs_get_dentry(sd); | |
929 | if (IS_ERR(old_dentry)) { | |
930 | error = PTR_ERR(old_dentry); | |
456ef155 | 931 | old_dentry = NULL; |
45aaae9c | 932 | goto out; |
51225039 | 933 | } |
5a26b79c | 934 | old_parent = old_dentry->d_parent; |
51225039 TH |
935 | |
936 | new_parent = sysfs_get_dentry(new_parent_sd); | |
937 | if (IS_ERR(new_parent)) { | |
938 | error = PTR_ERR(new_parent); | |
456ef155 | 939 | new_parent = NULL; |
45aaae9c | 940 | goto out; |
51225039 | 941 | } |
8a82472f CH |
942 | |
943 | again: | |
51225039 TH |
944 | mutex_lock(&old_parent->d_inode->i_mutex); |
945 | if (!mutex_trylock(&new_parent->d_inode->i_mutex)) { | |
946 | mutex_unlock(&old_parent->d_inode->i_mutex); | |
8a82472f CH |
947 | goto again; |
948 | } | |
45aaae9c | 949 | mutex_lock(&sysfs_mutex); |
8a82472f | 950 | |
45aaae9c EB |
951 | error = -EEXIST; |
952 | if (sysfs_find_dirent(new_parent_sd, sd->s_name)) | |
51225039 | 953 | goto out_unlock; |
45aaae9c EB |
954 | |
955 | error = -ENOMEM; | |
956 | new_dentry = d_alloc_name(new_parent, sd->s_name); | |
957 | if (!new_dentry) | |
958 | goto out_unlock; | |
959 | ||
960 | error = 0; | |
8a82472f | 961 | d_add(new_dentry, NULL); |
5a26b79c | 962 | d_move(old_dentry, new_dentry); |
8a82472f CH |
963 | |
964 | /* Remove from old parent's list and insert into new parent's list. */ | |
0c73f18b | 965 | sysfs_unlink_sibling(sd); |
7f7cfffe | 966 | sysfs_get(new_parent_sd); |
0f58b445 | 967 | drop_nlink(old_parent->d_inode); |
7f7cfffe TH |
968 | sysfs_put(sd->s_parent); |
969 | sd->s_parent = new_parent_sd; | |
0f58b445 | 970 | inc_nlink(new_parent->d_inode); |
0c73f18b | 971 | sysfs_link_sibling(sd); |
8a82472f | 972 | |
51225039 | 973 | out_unlock: |
45aaae9c | 974 | mutex_unlock(&sysfs_mutex); |
51225039 TH |
975 | mutex_unlock(&new_parent->d_inode->i_mutex); |
976 | mutex_unlock(&old_parent->d_inode->i_mutex); | |
45aaae9c | 977 | out: |
51225039 TH |
978 | dput(new_parent); |
979 | dput(old_dentry); | |
980 | dput(new_dentry); | |
932ea2e3 | 981 | mutex_unlock(&sysfs_rename_mutex); |
8a82472f CH |
982 | return error; |
983 | } | |
984 | ||
1da177e4 LT |
985 | /* Relationship between s_mode and the DT_xxx types */ |
986 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
987 | { | |
988 | return (sd->s_mode >> 12) & 15; | |
989 | } | |
990 | ||
991 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
992 | { | |
f427f5d5 | 993 | struct dentry *dentry = filp->f_path.dentry; |
1da177e4 | 994 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
3efa65b9 | 995 | struct sysfs_dirent *pos; |
1da177e4 | 996 | ino_t ino; |
1da177e4 | 997 | |
3efa65b9 EB |
998 | if (filp->f_pos == 0) { |
999 | ino = parent_sd->s_ino; | |
1000 | if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 1001 | filp->f_pos++; |
3efa65b9 EB |
1002 | } |
1003 | if (filp->f_pos == 1) { | |
1004 | if (parent_sd->s_parent) | |
1005 | ino = parent_sd->s_parent->s_ino; | |
1006 | else | |
1007 | ino = parent_sd->s_ino; | |
1008 | if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 1009 | filp->f_pos++; |
3efa65b9 EB |
1010 | } |
1011 | if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) { | |
1012 | mutex_lock(&sysfs_mutex); | |
0c73f18b | 1013 | |
3efa65b9 | 1014 | /* Skip the dentries we have already reported */ |
bc747f37 | 1015 | pos = parent_sd->s_dir.children; |
3efa65b9 EB |
1016 | while (pos && (filp->f_pos > pos->s_ino)) |
1017 | pos = pos->s_sibling; | |
3007e997 | 1018 | |
3efa65b9 EB |
1019 | for ( ; pos; pos = pos->s_sibling) { |
1020 | const char * name; | |
1021 | int len; | |
1da177e4 | 1022 | |
3efa65b9 EB |
1023 | name = pos->s_name; |
1024 | len = strlen(name); | |
1025 | filp->f_pos = ino = pos->s_ino; | |
1da177e4 | 1026 | |
3efa65b9 EB |
1027 | if (filldir(dirent, name, len, filp->f_pos, ino, |
1028 | dt_type(pos)) < 0) | |
1da177e4 | 1029 | break; |
1da177e4 | 1030 | } |
3efa65b9 EB |
1031 | if (!pos) |
1032 | filp->f_pos = INT_MAX; | |
3007e997 | 1033 | mutex_unlock(&sysfs_mutex); |
1da177e4 | 1034 | } |
3efa65b9 | 1035 | return 0; |
1da177e4 LT |
1036 | } |
1037 | ||
3efa65b9 | 1038 | |
4b6f5d20 | 1039 | const struct file_operations sysfs_dir_operations = { |
1da177e4 LT |
1040 | .read = generic_read_dir, |
1041 | .readdir = sysfs_readdir, | |
3222a3e5 | 1042 | .llseek = generic_file_llseek, |
1da177e4 | 1043 | }; |