Commit | Line | Data |
---|---|---|
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 | { |
6b0bfe93 EB |
467 | struct sysfs_inode_attrs *ps_iattr; |
468 | ||
0599ad53 | 469 | if (sysfs_find_dirent(acxt->parent_sd, sd->s_name)) |
23dc2799 TH |
470 | return -EEXIST; |
471 | ||
fb6896da TH |
472 | sd->s_parent = sysfs_get(acxt->parent_sd); |
473 | ||
474 | if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) | |
475 | inc_nlink(acxt->parent_inode); | |
476 | ||
477 | acxt->cnt++; | |
41fc1c27 TH |
478 | |
479 | sysfs_link_sibling(sd); | |
23dc2799 | 480 | |
6b0bfe93 EB |
481 | /* Update timestamps on the parent */ |
482 | ps_iattr = acxt->parent_sd->s_iattr; | |
483 | if (ps_iattr) { | |
484 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
485 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
486 | } | |
487 | ||
23dc2799 | 488 | return 0; |
fb6896da TH |
489 | } |
490 | ||
425cb029 AC |
491 | /** |
492 | * sysfs_pathname - return full path to sysfs dirent | |
493 | * @sd: sysfs_dirent whose path we want | |
494 | * @path: caller allocated buffer | |
495 | * | |
496 | * Gives the name "/" to the sysfs_root entry; any path returned | |
497 | * is relative to wherever sysfs is mounted. | |
498 | * | |
499 | * XXX: does no error checking on @path size | |
500 | */ | |
501 | static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) | |
502 | { | |
503 | if (sd->s_parent) { | |
504 | sysfs_pathname(sd->s_parent, path); | |
505 | strcat(path, "/"); | |
506 | } | |
507 | strcat(path, sd->s_name); | |
508 | return path; | |
509 | } | |
510 | ||
36ce6dad CH |
511 | /** |
512 | * sysfs_add_one - add sysfs_dirent to parent | |
513 | * @acxt: addrm context to use | |
514 | * @sd: sysfs_dirent to be added | |
515 | * | |
516 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
517 | * nlink of parent inode if @sd is a directory and link into the | |
518 | * children list of the parent. | |
519 | * | |
520 | * This function should be called between calls to | |
521 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
522 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
523 | * | |
524 | * LOCKING: | |
525 | * Determined by sysfs_addrm_start(). | |
526 | * | |
527 | * RETURNS: | |
528 | * 0 on success, -EEXIST if entry with the given name already | |
529 | * exists. | |
530 | */ | |
531 | int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
532 | { | |
533 | int ret; | |
534 | ||
535 | ret = __sysfs_add_one(acxt, sd); | |
425cb029 AC |
536 | if (ret == -EEXIST) { |
537 | char *path = kzalloc(PATH_MAX, GFP_KERNEL); | |
538 | WARN(1, KERN_WARNING | |
539 | "sysfs: cannot create duplicate filename '%s'\n", | |
540 | (path == NULL) ? sd->s_name : | |
541 | strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"), | |
542 | sd->s_name)); | |
543 | kfree(path); | |
544 | } | |
545 | ||
36ce6dad CH |
546 | return ret; |
547 | } | |
548 | ||
fb6896da TH |
549 | /** |
550 | * sysfs_remove_one - remove sysfs_dirent from parent | |
551 | * @acxt: addrm context to use | |
9fd5b1c9 | 552 | * @sd: sysfs_dirent to be removed |
fb6896da TH |
553 | * |
554 | * Mark @sd removed and drop nlink of parent inode if @sd is a | |
181b2e4b | 555 | * directory. @sd is unlinked from the children list. |
fb6896da TH |
556 | * |
557 | * This function should be called between calls to | |
558 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
559 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
560 | * | |
561 | * LOCKING: | |
562 | * Determined by sysfs_addrm_start(). | |
563 | */ | |
564 | void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
565 | { | |
6b0bfe93 EB |
566 | struct sysfs_inode_attrs *ps_iattr; |
567 | ||
41fc1c27 TH |
568 | BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED); |
569 | ||
570 | sysfs_unlink_sibling(sd); | |
fb6896da | 571 | |
6b0bfe93 EB |
572 | /* Update timestamps on the parent */ |
573 | ps_iattr = acxt->parent_sd->s_iattr; | |
574 | if (ps_iattr) { | |
575 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
576 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
577 | } | |
578 | ||
fb6896da TH |
579 | sd->s_flags |= SYSFS_FLAG_REMOVED; |
580 | sd->s_sibling = acxt->removed; | |
581 | acxt->removed = sd; | |
582 | ||
583 | if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) | |
584 | drop_nlink(acxt->parent_inode); | |
585 | ||
586 | acxt->cnt++; | |
587 | } | |
588 | ||
a0edd7c8 | 589 | /** |
e8f077c8 | 590 | * sysfs_dec_nlink - Decrement link count for the specified sysfs_dirent |
a0edd7c8 TH |
591 | * @sd: target sysfs_dirent |
592 | * | |
e8f077c8 | 593 | * Decrement nlink for @sd. @sd must have been unlinked from its |
a0edd7c8 TH |
594 | * parent on entry to this function such that it can't be looked |
595 | * up anymore. | |
a0edd7c8 | 596 | */ |
e8f077c8 | 597 | static void sysfs_dec_nlink(struct sysfs_dirent *sd) |
a0edd7c8 | 598 | { |
a0edd7c8 | 599 | struct inode *inode; |
89bec097 EB |
600 | |
601 | inode = ilookup(sysfs_sb, sd->s_ino); | |
602 | if (!inode) | |
603 | return; | |
a0edd7c8 | 604 | |
a0edd7c8 | 605 | /* adjust nlink and update timestamp */ |
89bec097 | 606 | mutex_lock(&inode->i_mutex); |
a0edd7c8 | 607 | |
89bec097 EB |
608 | inode->i_ctime = CURRENT_TIME; |
609 | drop_nlink(inode); | |
610 | if (sysfs_type(sd) == SYSFS_DIR) | |
a0edd7c8 | 611 | drop_nlink(inode); |
a0edd7c8 | 612 | |
89bec097 EB |
613 | mutex_unlock(&inode->i_mutex); |
614 | ||
615 | iput(inode); | |
a0edd7c8 TH |
616 | } |
617 | ||
fb6896da TH |
618 | /** |
619 | * sysfs_addrm_finish - finish up sysfs_dirent add/remove | |
620 | * @acxt: addrm context to finish up | |
621 | * | |
622 | * Finish up sysfs_dirent add/remove. Resources acquired by | |
623 | * sysfs_addrm_start() are released and removed sysfs_dirents are | |
624 | * cleaned up. Timestamps on the parent inode are updated. | |
625 | * | |
626 | * LOCKING: | |
627 | * All mutexes acquired by sysfs_addrm_start() are released. | |
fb6896da | 628 | */ |
990e53f8 | 629 | void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) |
fb6896da TH |
630 | { |
631 | /* release resources acquired by sysfs_addrm_start() */ | |
632 | mutex_unlock(&sysfs_mutex); | |
633 | if (acxt->parent_inode) { | |
634 | struct inode *inode = acxt->parent_inode; | |
635 | ||
636 | /* if added/removed, update timestamps on the parent */ | |
637 | if (acxt->cnt) | |
638 | inode->i_ctime = inode->i_mtime = CURRENT_TIME; | |
639 | ||
640 | mutex_unlock(&inode->i_mutex); | |
641 | iput(inode); | |
642 | } | |
643 | ||
644 | /* kill removed sysfs_dirents */ | |
645 | while (acxt->removed) { | |
646 | struct sysfs_dirent *sd = acxt->removed; | |
647 | ||
648 | acxt->removed = sd->s_sibling; | |
649 | sd->s_sibling = NULL; | |
650 | ||
e8f077c8 | 651 | sysfs_dec_nlink(sd); |
fb6896da | 652 | sysfs_deactivate(sd); |
e0edd3c6 | 653 | unmap_bin_file(sd); |
fb6896da | 654 | sysfs_put(sd); |
13b3086d | 655 | } |
b592fcfe EB |
656 | } |
657 | ||
f0b0af47 TH |
658 | /** |
659 | * sysfs_find_dirent - find sysfs_dirent with the given name | |
660 | * @parent_sd: sysfs_dirent to search under | |
661 | * @name: name to look for | |
662 | * | |
663 | * Look for sysfs_dirent with name @name under @parent_sd. | |
c516865c | 664 | * |
f0b0af47 | 665 | * LOCKING: |
3007e997 | 666 | * mutex_lock(sysfs_mutex) |
c516865c | 667 | * |
f0b0af47 TH |
668 | * RETURNS: |
669 | * Pointer to sysfs_dirent if found, NULL if not. | |
c516865c | 670 | */ |
f0b0af47 TH |
671 | struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, |
672 | const unsigned char *name) | |
c516865c | 673 | { |
f0b0af47 TH |
674 | struct sysfs_dirent *sd; |
675 | ||
bc747f37 | 676 | for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) |
3efa65b9 | 677 | if (!strcmp(sd->s_name, name)) |
f0b0af47 TH |
678 | return sd; |
679 | return NULL; | |
680 | } | |
c516865c | 681 | |
f0b0af47 TH |
682 | /** |
683 | * sysfs_get_dirent - find and get sysfs_dirent with the given name | |
684 | * @parent_sd: sysfs_dirent to search under | |
685 | * @name: name to look for | |
686 | * | |
687 | * Look for sysfs_dirent with name @name under @parent_sd and get | |
688 | * it if found. | |
689 | * | |
690 | * LOCKING: | |
3007e997 | 691 | * Kernel thread context (may sleep). Grabs sysfs_mutex. |
f0b0af47 TH |
692 | * |
693 | * RETURNS: | |
694 | * Pointer to sysfs_dirent if found, NULL if not. | |
695 | */ | |
696 | struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, | |
697 | const unsigned char *name) | |
698 | { | |
699 | struct sysfs_dirent *sd; | |
700 | ||
3007e997 | 701 | mutex_lock(&sysfs_mutex); |
f0b0af47 TH |
702 | sd = sysfs_find_dirent(parent_sd, name); |
703 | sysfs_get(sd); | |
3007e997 | 704 | mutex_unlock(&sysfs_mutex); |
f0b0af47 TH |
705 | |
706 | return sd; | |
c516865c | 707 | } |
f1282c84 | 708 | EXPORT_SYMBOL_GPL(sysfs_get_dirent); |
c516865c | 709 | |
608e266a TH |
710 | static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, |
711 | const char *name, struct sysfs_dirent **p_sd) | |
1da177e4 | 712 | { |
1da177e4 | 713 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; |
51225039 | 714 | struct sysfs_addrm_cxt acxt; |
dfeb9fb0 | 715 | struct sysfs_dirent *sd; |
23dc2799 | 716 | int rc; |
1da177e4 | 717 | |
fc9f54b9 | 718 | /* allocate */ |
3e519038 | 719 | sd = sysfs_new_dirent(name, mode, SYSFS_DIR); |
a26cd722 | 720 | if (!sd) |
51225039 | 721 | return -ENOMEM; |
b1fc3d61 | 722 | sd->s_dir.kobj = kobj; |
dfeb9fb0 | 723 | |
fc9f54b9 | 724 | /* link in */ |
51225039 | 725 | sysfs_addrm_start(&acxt, parent_sd); |
23dc2799 TH |
726 | rc = sysfs_add_one(&acxt, sd); |
727 | sysfs_addrm_finish(&acxt); | |
967e35dc | 728 | |
23dc2799 TH |
729 | if (rc == 0) |
730 | *p_sd = sd; | |
731 | else | |
967e35dc | 732 | sysfs_put(sd); |
dfeb9fb0 | 733 | |
23dc2799 | 734 | return rc; |
1da177e4 LT |
735 | } |
736 | ||
608e266a TH |
737 | int sysfs_create_subdir(struct kobject *kobj, const char *name, |
738 | struct sysfs_dirent **p_sd) | |
1da177e4 | 739 | { |
608e266a | 740 | return create_dir(kobj, kobj->sd, name, p_sd); |
1da177e4 LT |
741 | } |
742 | ||
743 | /** | |
744 | * sysfs_create_dir - create a directory for an object. | |
1da177e4 LT |
745 | * @kobj: object we're creating directory for. |
746 | */ | |
90bc6135 | 747 | int sysfs_create_dir(struct kobject * kobj) |
1da177e4 | 748 | { |
608e266a | 749 | struct sysfs_dirent *parent_sd, *sd; |
1da177e4 LT |
750 | int error = 0; |
751 | ||
752 | BUG_ON(!kobj); | |
753 | ||
90bc6135 | 754 | if (kobj->parent) |
608e266a | 755 | parent_sd = kobj->parent->sd; |
1da177e4 | 756 | else |
7d0c7d67 | 757 | parent_sd = &sysfs_root; |
1da177e4 | 758 | |
608e266a | 759 | error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd); |
1da177e4 | 760 | if (!error) |
608e266a | 761 | kobj->sd = sd; |
1da177e4 LT |
762 | return error; |
763 | } | |
764 | ||
1da177e4 LT |
765 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, |
766 | struct nameidata *nd) | |
767 | { | |
6cb52147 | 768 | struct dentry *ret = NULL; |
a7a04754 TH |
769 | struct sysfs_dirent *parent_sd = dentry->d_parent->d_fsdata; |
770 | struct sysfs_dirent *sd; | |
fc9f54b9 | 771 | struct inode *inode; |
1da177e4 | 772 | |
6cb52147 TH |
773 | mutex_lock(&sysfs_mutex); |
774 | ||
94777e09 | 775 | sd = sysfs_find_dirent(parent_sd, dentry->d_name.name); |
1da177e4 | 776 | |
fc9f54b9 | 777 | /* no such entry */ |
e49452c6 TH |
778 | if (!sd) { |
779 | ret = ERR_PTR(-ENOENT); | |
6cb52147 | 780 | goto out_unlock; |
e49452c6 | 781 | } |
fc9f54b9 TH |
782 | |
783 | /* attach dentry and inode */ | |
8312a8d7 | 784 | inode = sysfs_get_inode(sd); |
6cb52147 TH |
785 | if (!inode) { |
786 | ret = ERR_PTR(-ENOMEM); | |
787 | goto out_unlock; | |
788 | } | |
3007e997 | 789 | |
d6b4fd2f TH |
790 | /* instantiate and hash dentry */ |
791 | dentry->d_op = &sysfs_dentry_ops; | |
792 | dentry->d_fsdata = sysfs_get(sd); | |
119dd52b | 793 | d_instantiate(dentry, inode); |
d6b4fd2f | 794 | d_rehash(dentry); |
fc9f54b9 | 795 | |
6cb52147 | 796 | out_unlock: |
3007e997 | 797 | mutex_unlock(&sysfs_mutex); |
6cb52147 | 798 | return ret; |
1da177e4 LT |
799 | } |
800 | ||
c5ef1c42 | 801 | const struct inode_operations sysfs_dir_inode_operations = { |
1da177e4 | 802 | .lookup = sysfs_lookup, |
988d186d | 803 | .setattr = sysfs_setattr, |
ddd29ec6 | 804 | .setxattr = sysfs_setxattr, |
1da177e4 LT |
805 | }; |
806 | ||
608e266a | 807 | static void remove_dir(struct sysfs_dirent *sd) |
1da177e4 | 808 | { |
fb6896da | 809 | struct sysfs_addrm_cxt acxt; |
1da177e4 | 810 | |
fb6896da | 811 | sysfs_addrm_start(&acxt, sd->s_parent); |
fb6896da TH |
812 | sysfs_remove_one(&acxt, sd); |
813 | sysfs_addrm_finish(&acxt); | |
1da177e4 LT |
814 | } |
815 | ||
608e266a | 816 | void sysfs_remove_subdir(struct sysfs_dirent *sd) |
1da177e4 | 817 | { |
608e266a | 818 | remove_dir(sd); |
1da177e4 LT |
819 | } |
820 | ||
821 | ||
608e266a | 822 | static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) |
1da177e4 | 823 | { |
fb6896da | 824 | struct sysfs_addrm_cxt acxt; |
0c73f18b | 825 | struct sysfs_dirent **pos; |
1da177e4 | 826 | |
608e266a | 827 | if (!dir_sd) |
1da177e4 LT |
828 | return; |
829 | ||
608e266a | 830 | pr_debug("sysfs %s: removing dir\n", dir_sd->s_name); |
fb6896da | 831 | sysfs_addrm_start(&acxt, dir_sd); |
bc747f37 | 832 | pos = &dir_sd->s_dir.children; |
0c73f18b TH |
833 | while (*pos) { |
834 | struct sysfs_dirent *sd = *pos; | |
835 | ||
3efa65b9 | 836 | if (sysfs_type(sd) != SYSFS_DIR) |
fb6896da | 837 | sysfs_remove_one(&acxt, sd); |
41fc1c27 | 838 | else |
0c73f18b | 839 | pos = &(*pos)->s_sibling; |
1da177e4 | 840 | } |
fb6896da | 841 | sysfs_addrm_finish(&acxt); |
0ab66088 | 842 | |
608e266a | 843 | remove_dir(dir_sd); |
b592fcfe EB |
844 | } |
845 | ||
846 | /** | |
847 | * sysfs_remove_dir - remove an object's directory. | |
848 | * @kobj: object. | |
849 | * | |
850 | * The only thing special about this is that we remove any files in | |
851 | * the directory before we remove the directory, and we've inlined | |
852 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
853 | */ | |
854 | ||
855 | void sysfs_remove_dir(struct kobject * kobj) | |
856 | { | |
608e266a | 857 | struct sysfs_dirent *sd = kobj->sd; |
aecdceda | 858 | |
5f995323 | 859 | spin_lock(&sysfs_assoc_lock); |
608e266a | 860 | kobj->sd = NULL; |
5f995323 | 861 | spin_unlock(&sysfs_assoc_lock); |
aecdceda | 862 | |
608e266a | 863 | __sysfs_remove_dir(sd); |
1da177e4 LT |
864 | } |
865 | ||
90bc6135 | 866 | int sysfs_rename_dir(struct kobject * kobj, const char *new_name) |
1da177e4 | 867 | { |
9918f9a4 | 868 | struct sysfs_dirent *sd = kobj->sd; |
90bc6135 | 869 | struct dentry *parent = NULL; |
51225039 TH |
870 | struct dentry *old_dentry = NULL, *new_dentry = NULL; |
871 | const char *dup_name = NULL; | |
996b7376 | 872 | int error; |
1da177e4 | 873 | |
932ea2e3 EB |
874 | mutex_lock(&sysfs_rename_mutex); |
875 | ||
9918f9a4 EB |
876 | error = 0; |
877 | if (strcmp(sd->s_name, new_name) == 0) | |
878 | goto out; /* nothing to rename */ | |
879 | ||
ff869de7 | 880 | /* get the original dentry */ |
51225039 TH |
881 | old_dentry = sysfs_get_dentry(sd); |
882 | if (IS_ERR(old_dentry)) { | |
883 | error = PTR_ERR(old_dentry); | |
456ef155 | 884 | old_dentry = NULL; |
9918f9a4 | 885 | goto out; |
51225039 TH |
886 | } |
887 | ||
ff869de7 | 888 | parent = old_dentry->d_parent; |
1da177e4 | 889 | |
90bc6135 EB |
890 | /* lock parent and get dentry for new name */ |
891 | mutex_lock(&parent->d_inode->i_mutex); | |
9918f9a4 | 892 | mutex_lock(&sysfs_mutex); |
1da177e4 | 893 | |
9918f9a4 EB |
894 | error = -EEXIST; |
895 | if (sysfs_find_dirent(sd->s_parent, new_name)) | |
51225039 | 896 | goto out_unlock; |
996b7376 | 897 | |
9918f9a4 EB |
898 | error = -ENOMEM; |
899 | new_dentry = d_alloc_name(parent, new_name); | |
900 | if (!new_dentry) | |
51225039 | 901 | goto out_unlock; |
996b7376 | 902 | |
0b4a4fea | 903 | /* rename sysfs_dirent */ |
0c096b50 TH |
904 | error = -ENOMEM; |
905 | new_name = dup_name = kstrdup(new_name, GFP_KERNEL); | |
906 | if (!new_name) | |
9918f9a4 | 907 | goto out_unlock; |
0c096b50 | 908 | |
51225039 | 909 | dup_name = sd->s_name; |
0c096b50 TH |
910 | sd->s_name = new_name; |
911 | ||
ff869de7 | 912 | /* rename */ |
996b7376 | 913 | d_add(new_dentry, NULL); |
5a26b79c | 914 | d_move(old_dentry, new_dentry); |
996b7376 | 915 | |
996b7376 | 916 | error = 0; |
996b7376 | 917 | out_unlock: |
9918f9a4 | 918 | mutex_unlock(&sysfs_mutex); |
90bc6135 | 919 | mutex_unlock(&parent->d_inode->i_mutex); |
51225039 | 920 | kfree(dup_name); |
51225039 TH |
921 | dput(old_dentry); |
922 | dput(new_dentry); | |
9918f9a4 | 923 | out: |
932ea2e3 | 924 | mutex_unlock(&sysfs_rename_mutex); |
1da177e4 LT |
925 | return error; |
926 | } | |
927 | ||
51225039 | 928 | int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) |
8a82472f | 929 | { |
51225039 TH |
930 | struct sysfs_dirent *sd = kobj->sd; |
931 | struct sysfs_dirent *new_parent_sd; | |
932 | struct dentry *old_parent, *new_parent = NULL; | |
933 | struct dentry *old_dentry = NULL, *new_dentry = NULL; | |
8a82472f CH |
934 | int error; |
935 | ||
932ea2e3 | 936 | mutex_lock(&sysfs_rename_mutex); |
51225039 | 937 | BUG_ON(!sd->s_parent); |
a6a83577 CH |
938 | new_parent_sd = (new_parent_kobj && new_parent_kobj->sd) ? |
939 | new_parent_kobj->sd : &sysfs_root; | |
51225039 | 940 | |
45aaae9c EB |
941 | error = 0; |
942 | if (sd->s_parent == new_parent_sd) | |
943 | goto out; /* nothing to move */ | |
944 | ||
51225039 TH |
945 | /* get dentries */ |
946 | old_dentry = sysfs_get_dentry(sd); | |
947 | if (IS_ERR(old_dentry)) { | |
948 | error = PTR_ERR(old_dentry); | |
456ef155 | 949 | old_dentry = NULL; |
45aaae9c | 950 | goto out; |
51225039 | 951 | } |
5a26b79c | 952 | old_parent = old_dentry->d_parent; |
51225039 TH |
953 | |
954 | new_parent = sysfs_get_dentry(new_parent_sd); | |
955 | if (IS_ERR(new_parent)) { | |
956 | error = PTR_ERR(new_parent); | |
456ef155 | 957 | new_parent = NULL; |
45aaae9c | 958 | goto out; |
51225039 | 959 | } |
8a82472f CH |
960 | |
961 | again: | |
51225039 TH |
962 | mutex_lock(&old_parent->d_inode->i_mutex); |
963 | if (!mutex_trylock(&new_parent->d_inode->i_mutex)) { | |
964 | mutex_unlock(&old_parent->d_inode->i_mutex); | |
8a82472f CH |
965 | goto again; |
966 | } | |
45aaae9c | 967 | mutex_lock(&sysfs_mutex); |
8a82472f | 968 | |
45aaae9c EB |
969 | error = -EEXIST; |
970 | if (sysfs_find_dirent(new_parent_sd, sd->s_name)) | |
51225039 | 971 | goto out_unlock; |
45aaae9c EB |
972 | |
973 | error = -ENOMEM; | |
974 | new_dentry = d_alloc_name(new_parent, sd->s_name); | |
975 | if (!new_dentry) | |
976 | goto out_unlock; | |
977 | ||
978 | error = 0; | |
8a82472f | 979 | d_add(new_dentry, NULL); |
5a26b79c | 980 | d_move(old_dentry, new_dentry); |
8a82472f CH |
981 | |
982 | /* Remove from old parent's list and insert into new parent's list. */ | |
0c73f18b | 983 | sysfs_unlink_sibling(sd); |
7f7cfffe | 984 | sysfs_get(new_parent_sd); |
0f58b445 | 985 | drop_nlink(old_parent->d_inode); |
7f7cfffe TH |
986 | sysfs_put(sd->s_parent); |
987 | sd->s_parent = new_parent_sd; | |
0f58b445 | 988 | inc_nlink(new_parent->d_inode); |
0c73f18b | 989 | sysfs_link_sibling(sd); |
8a82472f | 990 | |
51225039 | 991 | out_unlock: |
45aaae9c | 992 | mutex_unlock(&sysfs_mutex); |
51225039 TH |
993 | mutex_unlock(&new_parent->d_inode->i_mutex); |
994 | mutex_unlock(&old_parent->d_inode->i_mutex); | |
45aaae9c | 995 | out: |
51225039 TH |
996 | dput(new_parent); |
997 | dput(old_dentry); | |
998 | dput(new_dentry); | |
932ea2e3 | 999 | mutex_unlock(&sysfs_rename_mutex); |
8a82472f CH |
1000 | return error; |
1001 | } | |
1002 | ||
1da177e4 LT |
1003 | /* Relationship between s_mode and the DT_xxx types */ |
1004 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
1005 | { | |
1006 | return (sd->s_mode >> 12) & 15; | |
1007 | } | |
1008 | ||
1009 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
1010 | { | |
f427f5d5 | 1011 | struct dentry *dentry = filp->f_path.dentry; |
1da177e4 | 1012 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
3efa65b9 | 1013 | struct sysfs_dirent *pos; |
1da177e4 | 1014 | ino_t ino; |
1da177e4 | 1015 | |
3efa65b9 EB |
1016 | if (filp->f_pos == 0) { |
1017 | ino = parent_sd->s_ino; | |
1018 | if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 1019 | filp->f_pos++; |
3efa65b9 EB |
1020 | } |
1021 | if (filp->f_pos == 1) { | |
1022 | if (parent_sd->s_parent) | |
1023 | ino = parent_sd->s_parent->s_ino; | |
1024 | else | |
1025 | ino = parent_sd->s_ino; | |
1026 | if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 1027 | filp->f_pos++; |
3efa65b9 EB |
1028 | } |
1029 | if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) { | |
1030 | mutex_lock(&sysfs_mutex); | |
0c73f18b | 1031 | |
3efa65b9 | 1032 | /* Skip the dentries we have already reported */ |
bc747f37 | 1033 | pos = parent_sd->s_dir.children; |
3efa65b9 EB |
1034 | while (pos && (filp->f_pos > pos->s_ino)) |
1035 | pos = pos->s_sibling; | |
3007e997 | 1036 | |
3efa65b9 EB |
1037 | for ( ; pos; pos = pos->s_sibling) { |
1038 | const char * name; | |
1039 | int len; | |
1da177e4 | 1040 | |
3efa65b9 EB |
1041 | name = pos->s_name; |
1042 | len = strlen(name); | |
1043 | filp->f_pos = ino = pos->s_ino; | |
1da177e4 | 1044 | |
3efa65b9 EB |
1045 | if (filldir(dirent, name, len, filp->f_pos, ino, |
1046 | dt_type(pos)) < 0) | |
1da177e4 | 1047 | break; |
1da177e4 | 1048 | } |
3efa65b9 EB |
1049 | if (!pos) |
1050 | filp->f_pos = INT_MAX; | |
3007e997 | 1051 | mutex_unlock(&sysfs_mutex); |
1da177e4 | 1052 | } |
3efa65b9 | 1053 | return 0; |
1da177e4 LT |
1054 | } |
1055 | ||
3efa65b9 | 1056 | |
4b6f5d20 | 1057 | const struct file_operations sysfs_dir_operations = { |
1da177e4 LT |
1058 | .read = generic_read_dir, |
1059 | .readdir = sysfs_readdir, | |
3222a3e5 | 1060 | .llseek = generic_file_llseek, |
1da177e4 | 1061 | }; |