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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); |
f7a75f0a | 28 | DEFINE_SPINLOCK(sysfs_assoc_lock); |
1da177e4 | 29 | |
f7a75f0a | 30 | static DEFINE_SPINLOCK(sysfs_ino_lock); |
2b611bb7 TH |
31 | static DEFINE_IDA(sysfs_ino_ida); |
32 | ||
0c73f18b TH |
33 | /** |
34 | * sysfs_link_sibling - link sysfs_dirent into sibling list | |
35 | * @sd: sysfs_dirent of interest | |
36 | * | |
37 | * Link @sd into its sibling list which starts from | |
bc747f37 | 38 | * sd->s_parent->s_dir.children. |
0c73f18b TH |
39 | * |
40 | * Locking: | |
3007e997 | 41 | * mutex_lock(sysfs_mutex) |
0c73f18b | 42 | */ |
41fc1c27 | 43 | static void sysfs_link_sibling(struct sysfs_dirent *sd) |
0c73f18b TH |
44 | { |
45 | struct sysfs_dirent *parent_sd = sd->s_parent; | |
3efa65b9 | 46 | struct sysfs_dirent **pos; |
0c73f18b TH |
47 | |
48 | BUG_ON(sd->s_sibling); | |
3efa65b9 EB |
49 | |
50 | /* Store directory entries in order by ino. This allows | |
51 | * readdir to properly restart without having to add a | |
bc747f37 | 52 | * cursor into the s_dir.children list. |
3efa65b9 | 53 | */ |
bc747f37 | 54 | for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) { |
3efa65b9 EB |
55 | if (sd->s_ino < (*pos)->s_ino) |
56 | break; | |
57 | } | |
58 | sd->s_sibling = *pos; | |
59 | *pos = sd; | |
0c73f18b TH |
60 | } |
61 | ||
62 | /** | |
63 | * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list | |
64 | * @sd: sysfs_dirent of interest | |
65 | * | |
66 | * Unlink @sd from its sibling list which starts from | |
bc747f37 | 67 | * sd->s_parent->s_dir.children. |
0c73f18b TH |
68 | * |
69 | * Locking: | |
3007e997 | 70 | * mutex_lock(sysfs_mutex) |
0c73f18b | 71 | */ |
41fc1c27 | 72 | static void sysfs_unlink_sibling(struct sysfs_dirent *sd) |
0c73f18b TH |
73 | { |
74 | struct sysfs_dirent **pos; | |
75 | ||
bc747f37 TH |
76 | for (pos = &sd->s_parent->s_dir.children; *pos; |
77 | pos = &(*pos)->s_sibling) { | |
0c73f18b TH |
78 | if (*pos == sd) { |
79 | *pos = sd->s_sibling; | |
80 | sd->s_sibling = NULL; | |
81 | break; | |
82 | } | |
83 | } | |
84 | } | |
85 | ||
b6b4a439 TH |
86 | /** |
87 | * sysfs_get_active - get an active reference to sysfs_dirent | |
88 | * @sd: sysfs_dirent to get an active reference to | |
89 | * | |
90 | * Get an active reference of @sd. This function is noop if @sd | |
91 | * is NULL. | |
92 | * | |
93 | * RETURNS: | |
94 | * Pointer to @sd on success, NULL on failure. | |
95 | */ | |
78e9d367 | 96 | static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) |
b6b4a439 | 97 | { |
8619f979 TH |
98 | if (unlikely(!sd)) |
99 | return NULL; | |
100 | ||
101 | while (1) { | |
102 | int v, t; | |
103 | ||
104 | v = atomic_read(&sd->s_active); | |
105 | if (unlikely(v < 0)) | |
106 | return NULL; | |
107 | ||
108 | t = atomic_cmpxchg(&sd->s_active, v, v + 1); | |
846f9974 EB |
109 | if (likely(t == v)) { |
110 | rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); | |
8619f979 | 111 | return sd; |
846f9974 | 112 | } |
8619f979 TH |
113 | if (t < 0) |
114 | return NULL; | |
115 | ||
116 | cpu_relax(); | |
b6b4a439 | 117 | } |
b6b4a439 TH |
118 | } |
119 | ||
120 | /** | |
121 | * sysfs_put_active - put an active reference to sysfs_dirent | |
122 | * @sd: sysfs_dirent to put an active reference to | |
123 | * | |
124 | * Put an active reference to @sd. This function is noop if @sd | |
125 | * is NULL. | |
126 | */ | |
78e9d367 | 127 | static void sysfs_put_active(struct sysfs_dirent *sd) |
b6b4a439 | 128 | { |
8619f979 TH |
129 | struct completion *cmpl; |
130 | int v; | |
131 | ||
132 | if (unlikely(!sd)) | |
133 | return; | |
134 | ||
846f9974 | 135 | rwsem_release(&sd->dep_map, 1, _RET_IP_); |
8619f979 TH |
136 | v = atomic_dec_return(&sd->s_active); |
137 | if (likely(v != SD_DEACTIVATED_BIAS)) | |
138 | return; | |
139 | ||
140 | /* atomic_dec_return() is a mb(), we'll always see the updated | |
0c73f18b | 141 | * sd->s_sibling. |
8619f979 | 142 | */ |
0c73f18b | 143 | cmpl = (void *)sd->s_sibling; |
8619f979 | 144 | complete(cmpl); |
b6b4a439 TH |
145 | } |
146 | ||
147 | /** | |
148 | * sysfs_get_active_two - get active references to sysfs_dirent and parent | |
149 | * @sd: sysfs_dirent of interest | |
150 | * | |
151 | * Get active reference to @sd and its parent. Parent's active | |
152 | * reference is grabbed first. This function is noop if @sd is | |
153 | * NULL. | |
154 | * | |
155 | * RETURNS: | |
156 | * Pointer to @sd on success, NULL on failure. | |
157 | */ | |
158 | struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd) | |
159 | { | |
160 | if (sd) { | |
161 | if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent))) | |
162 | return NULL; | |
163 | if (unlikely(!sysfs_get_active(sd))) { | |
164 | sysfs_put_active(sd->s_parent); | |
165 | return NULL; | |
166 | } | |
167 | } | |
168 | return sd; | |
169 | } | |
170 | ||
171 | /** | |
172 | * sysfs_put_active_two - put active references to sysfs_dirent and parent | |
173 | * @sd: sysfs_dirent of interest | |
174 | * | |
175 | * Put active references to @sd and its parent. This function is | |
176 | * noop if @sd is NULL. | |
177 | */ | |
178 | void sysfs_put_active_two(struct sysfs_dirent *sd) | |
179 | { | |
180 | if (sd) { | |
181 | sysfs_put_active(sd); | |
182 | sysfs_put_active(sd->s_parent); | |
183 | } | |
184 | } | |
185 | ||
186 | /** | |
187 | * sysfs_deactivate - deactivate sysfs_dirent | |
188 | * @sd: sysfs_dirent to deactivate | |
189 | * | |
8619f979 | 190 | * Deny new active references and drain existing ones. |
b6b4a439 | 191 | */ |
fb6896da | 192 | static void sysfs_deactivate(struct sysfs_dirent *sd) |
b6b4a439 | 193 | { |
8619f979 TH |
194 | DECLARE_COMPLETION_ONSTACK(wait); |
195 | int v; | |
b6b4a439 | 196 | |
380e6fbb | 197 | BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED)); |
0c73f18b | 198 | sd->s_sibling = (void *)&wait; |
8619f979 | 199 | |
846f9974 | 200 | rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_); |
8619f979 | 201 | /* atomic_add_return() is a mb(), put_active() will always see |
0c73f18b | 202 | * the updated sd->s_sibling. |
b6b4a439 | 203 | */ |
8619f979 TH |
204 | v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); |
205 | ||
846f9974 EB |
206 | if (v != SD_DEACTIVATED_BIAS) { |
207 | lock_contended(&sd->dep_map, _RET_IP_); | |
8619f979 | 208 | wait_for_completion(&wait); |
846f9974 | 209 | } |
8619f979 | 210 | |
0c73f18b | 211 | sd->s_sibling = NULL; |
846f9974 EB |
212 | |
213 | lock_acquired(&sd->dep_map, _RET_IP_); | |
214 | rwsem_release(&sd->dep_map, 1, _RET_IP_); | |
b6b4a439 TH |
215 | } |
216 | ||
42b37df6 | 217 | static int sysfs_alloc_ino(ino_t *pino) |
2b611bb7 TH |
218 | { |
219 | int ino, rc; | |
220 | ||
221 | retry: | |
222 | spin_lock(&sysfs_ino_lock); | |
223 | rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino); | |
224 | spin_unlock(&sysfs_ino_lock); | |
225 | ||
226 | if (rc == -EAGAIN) { | |
227 | if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL)) | |
228 | goto retry; | |
229 | rc = -ENOMEM; | |
230 | } | |
231 | ||
232 | *pino = ino; | |
233 | return rc; | |
234 | } | |
235 | ||
236 | static void sysfs_free_ino(ino_t ino) | |
237 | { | |
238 | spin_lock(&sysfs_ino_lock); | |
239 | ida_remove(&sysfs_ino_ida, ino); | |
240 | spin_unlock(&sysfs_ino_lock); | |
241 | } | |
242 | ||
fa7f912a TH |
243 | void release_sysfs_dirent(struct sysfs_dirent * sd) |
244 | { | |
13b3086d TH |
245 | struct sysfs_dirent *parent_sd; |
246 | ||
247 | repeat: | |
3007e997 TH |
248 | /* Moving/renaming is always done while holding reference. |
249 | * sd->s_parent won't change beneath us. | |
250 | */ | |
13b3086d TH |
251 | parent_sd = sd->s_parent; |
252 | ||
b402d72c | 253 | if (sysfs_type(sd) == SYSFS_KOBJ_LINK) |
b1fc3d61 | 254 | sysfs_put(sd->s_symlink.target_sd); |
b402d72c | 255 | if (sysfs_type(sd) & SYSFS_COPY_NAME) |
0c096b50 | 256 | kfree(sd->s_name); |
4c3da220 EB |
257 | if (sd->s_iattr && sd->s_iattr->ia_secdata) |
258 | security_release_secctx(sd->s_iattr->ia_secdata, | |
259 | sd->s_iattr->ia_secdata_len); | |
fa7f912a | 260 | kfree(sd->s_iattr); |
2b611bb7 | 261 | sysfs_free_ino(sd->s_ino); |
fa7f912a | 262 | kmem_cache_free(sysfs_dir_cachep, sd); |
13b3086d TH |
263 | |
264 | sd = parent_sd; | |
265 | if (sd && atomic_dec_and_test(&sd->s_count)) | |
266 | goto repeat; | |
fa7f912a TH |
267 | } |
268 | ||
e8f077c8 EB |
269 | static int sysfs_dentry_delete(struct dentry *dentry) |
270 | { | |
271 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
272 | return !!(sd->s_flags & SYSFS_FLAG_REMOVED); | |
273 | } | |
274 | ||
275 | static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) | |
276 | { | |
277 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
278 | int is_dir; | |
279 | ||
280 | mutex_lock(&sysfs_mutex); | |
281 | ||
282 | /* The sysfs dirent has been deleted */ | |
283 | if (sd->s_flags & SYSFS_FLAG_REMOVED) | |
284 | goto out_bad; | |
285 | ||
832b6af1 EB |
286 | /* The sysfs dirent has been moved? */ |
287 | if (dentry->d_parent->d_fsdata != sd->s_parent) | |
288 | goto out_bad; | |
289 | ||
290 | /* The sysfs dirent has been renamed */ | |
291 | if (strcmp(dentry->d_name.name, sd->s_name) != 0) | |
292 | goto out_bad; | |
293 | ||
e8f077c8 EB |
294 | mutex_unlock(&sysfs_mutex); |
295 | out_valid: | |
296 | return 1; | |
297 | out_bad: | |
298 | /* Remove the dentry from the dcache hashes. | |
299 | * If this is a deleted dentry we use d_drop instead of d_delete | |
300 | * so sysfs doesn't need to cope with negative dentries. | |
832b6af1 EB |
301 | * |
302 | * If this is a dentry that has simply been renamed we | |
303 | * use d_drop to remove it from the dcache lookup on its | |
304 | * old parent. If this dentry persists later when a lookup | |
305 | * is performed at its new name the dentry will be readded | |
306 | * to the dcache hashes. | |
e8f077c8 EB |
307 | */ |
308 | is_dir = (sysfs_type(sd) == SYSFS_DIR); | |
309 | mutex_unlock(&sysfs_mutex); | |
310 | if (is_dir) { | |
311 | /* If we have submounts we must allow the vfs caches | |
312 | * to lie about the state of the filesystem to prevent | |
313 | * leaks and other nasty things. | |
314 | */ | |
315 | if (have_submounts(dentry)) | |
316 | goto out_valid; | |
317 | shrink_dcache_parent(dentry); | |
318 | } | |
319 | d_drop(dentry); | |
320 | return 0; | |
321 | } | |
322 | ||
28a027cf | 323 | static void sysfs_dentry_iput(struct dentry *dentry, struct inode *inode) |
1da177e4 LT |
324 | { |
325 | struct sysfs_dirent * sd = dentry->d_fsdata; | |
326 | ||
5a26b79c | 327 | sysfs_put(sd); |
1da177e4 LT |
328 | iput(inode); |
329 | } | |
330 | ||
ee1ec329 | 331 | static const struct dentry_operations sysfs_dentry_ops = { |
e8f077c8 EB |
332 | .d_revalidate = sysfs_dentry_revalidate, |
333 | .d_delete = sysfs_dentry_delete, | |
28a027cf | 334 | .d_iput = sysfs_dentry_iput, |
1da177e4 LT |
335 | }; |
336 | ||
3e519038 | 337 | struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) |
1da177e4 | 338 | { |
0c096b50 | 339 | char *dup_name = NULL; |
01da2425 | 340 | struct sysfs_dirent *sd; |
0c096b50 TH |
341 | |
342 | if (type & SYSFS_COPY_NAME) { | |
343 | name = dup_name = kstrdup(name, GFP_KERNEL); | |
344 | if (!name) | |
01da2425 | 345 | return NULL; |
0c096b50 | 346 | } |
1da177e4 | 347 | |
c3762229 | 348 | sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); |
1da177e4 | 349 | if (!sd) |
01da2425 | 350 | goto err_out1; |
1da177e4 | 351 | |
0c096b50 | 352 | if (sysfs_alloc_ino(&sd->s_ino)) |
01da2425 | 353 | goto err_out2; |
2b611bb7 | 354 | |
1da177e4 | 355 | atomic_set(&sd->s_count, 1); |
8619f979 | 356 | atomic_set(&sd->s_active, 0); |
846f9974 | 357 | sysfs_dirent_init_lockdep(sd); |
a26cd722 | 358 | |
0c096b50 | 359 | sd->s_name = name; |
a26cd722 | 360 | sd->s_mode = mode; |
b402d72c | 361 | sd->s_flags = type; |
1da177e4 LT |
362 | |
363 | return sd; | |
0c096b50 | 364 | |
01da2425 | 365 | err_out2: |
0c096b50 | 366 | kmem_cache_free(sysfs_dir_cachep, sd); |
01da2425 AM |
367 | err_out1: |
368 | kfree(dup_name); | |
0c096b50 | 369 | return NULL; |
1da177e4 LT |
370 | } |
371 | ||
3007e997 | 372 | /** |
fb6896da TH |
373 | * sysfs_addrm_start - prepare for sysfs_dirent add/remove |
374 | * @acxt: pointer to sysfs_addrm_cxt to be used | |
375 | * @parent_sd: parent sysfs_dirent | |
3007e997 | 376 | * |
fb6896da TH |
377 | * This function is called when the caller is about to add or |
378 | * remove sysfs_dirent under @parent_sd. This function acquires | |
a16bbc34 | 379 | * sysfs_mutex. @acxt is used to keep and pass context to |
fb6896da | 380 | * other addrm functions. |
3007e997 TH |
381 | * |
382 | * LOCKING: | |
fb6896da | 383 | * Kernel thread context (may sleep). sysfs_mutex is locked on |
a16bbc34 | 384 | * return. |
3007e997 | 385 | */ |
fb6896da TH |
386 | void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, |
387 | struct sysfs_dirent *parent_sd) | |
b592fcfe | 388 | { |
fb6896da TH |
389 | memset(acxt, 0, sizeof(*acxt)); |
390 | acxt->parent_sd = parent_sd; | |
391 | ||
fb6896da | 392 | mutex_lock(&sysfs_mutex); |
fb6896da TH |
393 | } |
394 | ||
395 | /** | |
36ce6dad | 396 | * __sysfs_add_one - add sysfs_dirent to parent without warning |
fb6896da TH |
397 | * @acxt: addrm context to use |
398 | * @sd: sysfs_dirent to be added | |
399 | * | |
400 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
181b2e4b TH |
401 | * nlink of parent inode if @sd is a directory and link into the |
402 | * children list of the parent. | |
fb6896da TH |
403 | * |
404 | * This function should be called between calls to | |
405 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
406 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
407 | * | |
408 | * LOCKING: | |
409 | * Determined by sysfs_addrm_start(). | |
23dc2799 TH |
410 | * |
411 | * RETURNS: | |
412 | * 0 on success, -EEXIST if entry with the given name already | |
413 | * exists. | |
fb6896da | 414 | */ |
36ce6dad | 415 | int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) |
fb6896da | 416 | { |
6b0bfe93 EB |
417 | struct sysfs_inode_attrs *ps_iattr; |
418 | ||
0599ad53 | 419 | if (sysfs_find_dirent(acxt->parent_sd, sd->s_name)) |
23dc2799 TH |
420 | return -EEXIST; |
421 | ||
fb6896da TH |
422 | sd->s_parent = sysfs_get(acxt->parent_sd); |
423 | ||
41fc1c27 | 424 | sysfs_link_sibling(sd); |
23dc2799 | 425 | |
6b0bfe93 EB |
426 | /* Update timestamps on the parent */ |
427 | ps_iattr = acxt->parent_sd->s_iattr; | |
428 | if (ps_iattr) { | |
429 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
430 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
431 | } | |
432 | ||
23dc2799 | 433 | return 0; |
fb6896da TH |
434 | } |
435 | ||
425cb029 AC |
436 | /** |
437 | * sysfs_pathname - return full path to sysfs dirent | |
438 | * @sd: sysfs_dirent whose path we want | |
439 | * @path: caller allocated buffer | |
440 | * | |
441 | * Gives the name "/" to the sysfs_root entry; any path returned | |
442 | * is relative to wherever sysfs is mounted. | |
443 | * | |
444 | * XXX: does no error checking on @path size | |
445 | */ | |
446 | static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) | |
447 | { | |
448 | if (sd->s_parent) { | |
449 | sysfs_pathname(sd->s_parent, path); | |
450 | strcat(path, "/"); | |
451 | } | |
452 | strcat(path, sd->s_name); | |
453 | return path; | |
454 | } | |
455 | ||
36ce6dad CH |
456 | /** |
457 | * sysfs_add_one - add sysfs_dirent to parent | |
458 | * @acxt: addrm context to use | |
459 | * @sd: sysfs_dirent to be added | |
460 | * | |
461 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
462 | * nlink of parent inode if @sd is a directory and link into the | |
463 | * children list of the parent. | |
464 | * | |
465 | * This function should be called between calls to | |
466 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
467 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
468 | * | |
469 | * LOCKING: | |
470 | * Determined by sysfs_addrm_start(). | |
471 | * | |
472 | * RETURNS: | |
473 | * 0 on success, -EEXIST if entry with the given name already | |
474 | * exists. | |
475 | */ | |
476 | int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
477 | { | |
478 | int ret; | |
479 | ||
480 | ret = __sysfs_add_one(acxt, sd); | |
425cb029 AC |
481 | if (ret == -EEXIST) { |
482 | char *path = kzalloc(PATH_MAX, GFP_KERNEL); | |
483 | WARN(1, KERN_WARNING | |
484 | "sysfs: cannot create duplicate filename '%s'\n", | |
485 | (path == NULL) ? sd->s_name : | |
486 | strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"), | |
487 | sd->s_name)); | |
488 | kfree(path); | |
489 | } | |
490 | ||
36ce6dad CH |
491 | return ret; |
492 | } | |
493 | ||
fb6896da TH |
494 | /** |
495 | * sysfs_remove_one - remove sysfs_dirent from parent | |
496 | * @acxt: addrm context to use | |
9fd5b1c9 | 497 | * @sd: sysfs_dirent to be removed |
fb6896da TH |
498 | * |
499 | * Mark @sd removed and drop nlink of parent inode if @sd is a | |
181b2e4b | 500 | * directory. @sd is unlinked from the children list. |
fb6896da TH |
501 | * |
502 | * This function should be called between calls to | |
503 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
504 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
505 | * | |
506 | * LOCKING: | |
507 | * Determined by sysfs_addrm_start(). | |
508 | */ | |
509 | void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
510 | { | |
6b0bfe93 EB |
511 | struct sysfs_inode_attrs *ps_iattr; |
512 | ||
41fc1c27 TH |
513 | BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED); |
514 | ||
515 | sysfs_unlink_sibling(sd); | |
fb6896da | 516 | |
6b0bfe93 EB |
517 | /* Update timestamps on the parent */ |
518 | ps_iattr = acxt->parent_sd->s_iattr; | |
519 | if (ps_iattr) { | |
520 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
521 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
522 | } | |
523 | ||
fb6896da TH |
524 | sd->s_flags |= SYSFS_FLAG_REMOVED; |
525 | sd->s_sibling = acxt->removed; | |
526 | acxt->removed = sd; | |
a0edd7c8 TH |
527 | } |
528 | ||
fb6896da TH |
529 | /** |
530 | * sysfs_addrm_finish - finish up sysfs_dirent add/remove | |
531 | * @acxt: addrm context to finish up | |
532 | * | |
533 | * Finish up sysfs_dirent add/remove. Resources acquired by | |
534 | * sysfs_addrm_start() are released and removed sysfs_dirents are | |
a16bbc34 | 535 | * cleaned up. |
fb6896da TH |
536 | * |
537 | * LOCKING: | |
a16bbc34 | 538 | * sysfs_mutex is released. |
fb6896da | 539 | */ |
990e53f8 | 540 | void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) |
fb6896da TH |
541 | { |
542 | /* release resources acquired by sysfs_addrm_start() */ | |
543 | mutex_unlock(&sysfs_mutex); | |
fb6896da TH |
544 | |
545 | /* kill removed sysfs_dirents */ | |
546 | while (acxt->removed) { | |
547 | struct sysfs_dirent *sd = acxt->removed; | |
548 | ||
549 | acxt->removed = sd->s_sibling; | |
550 | sd->s_sibling = NULL; | |
551 | ||
fb6896da | 552 | sysfs_deactivate(sd); |
e0edd3c6 | 553 | unmap_bin_file(sd); |
fb6896da | 554 | sysfs_put(sd); |
13b3086d | 555 | } |
b592fcfe EB |
556 | } |
557 | ||
f0b0af47 TH |
558 | /** |
559 | * sysfs_find_dirent - find sysfs_dirent with the given name | |
560 | * @parent_sd: sysfs_dirent to search under | |
561 | * @name: name to look for | |
562 | * | |
563 | * Look for sysfs_dirent with name @name under @parent_sd. | |
c516865c | 564 | * |
f0b0af47 | 565 | * LOCKING: |
3007e997 | 566 | * mutex_lock(sysfs_mutex) |
c516865c | 567 | * |
f0b0af47 TH |
568 | * RETURNS: |
569 | * Pointer to sysfs_dirent if found, NULL if not. | |
c516865c | 570 | */ |
f0b0af47 TH |
571 | struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, |
572 | const unsigned char *name) | |
c516865c | 573 | { |
f0b0af47 TH |
574 | struct sysfs_dirent *sd; |
575 | ||
bc747f37 | 576 | for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) |
3efa65b9 | 577 | if (!strcmp(sd->s_name, name)) |
f0b0af47 TH |
578 | return sd; |
579 | return NULL; | |
580 | } | |
c516865c | 581 | |
f0b0af47 TH |
582 | /** |
583 | * sysfs_get_dirent - find and get sysfs_dirent with the given name | |
584 | * @parent_sd: sysfs_dirent to search under | |
585 | * @name: name to look for | |
586 | * | |
587 | * Look for sysfs_dirent with name @name under @parent_sd and get | |
588 | * it if found. | |
589 | * | |
590 | * LOCKING: | |
3007e997 | 591 | * Kernel thread context (may sleep). Grabs sysfs_mutex. |
f0b0af47 TH |
592 | * |
593 | * RETURNS: | |
594 | * Pointer to sysfs_dirent if found, NULL if not. | |
595 | */ | |
596 | struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, | |
597 | const unsigned char *name) | |
598 | { | |
599 | struct sysfs_dirent *sd; | |
600 | ||
3007e997 | 601 | mutex_lock(&sysfs_mutex); |
f0b0af47 TH |
602 | sd = sysfs_find_dirent(parent_sd, name); |
603 | sysfs_get(sd); | |
3007e997 | 604 | mutex_unlock(&sysfs_mutex); |
f0b0af47 TH |
605 | |
606 | return sd; | |
c516865c | 607 | } |
f1282c84 | 608 | EXPORT_SYMBOL_GPL(sysfs_get_dirent); |
c516865c | 609 | |
608e266a TH |
610 | static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, |
611 | const char *name, struct sysfs_dirent **p_sd) | |
1da177e4 | 612 | { |
1da177e4 | 613 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; |
51225039 | 614 | struct sysfs_addrm_cxt acxt; |
dfeb9fb0 | 615 | struct sysfs_dirent *sd; |
23dc2799 | 616 | int rc; |
1da177e4 | 617 | |
fc9f54b9 | 618 | /* allocate */ |
3e519038 | 619 | sd = sysfs_new_dirent(name, mode, SYSFS_DIR); |
a26cd722 | 620 | if (!sd) |
51225039 | 621 | return -ENOMEM; |
b1fc3d61 | 622 | sd->s_dir.kobj = kobj; |
dfeb9fb0 | 623 | |
fc9f54b9 | 624 | /* link in */ |
51225039 | 625 | sysfs_addrm_start(&acxt, parent_sd); |
23dc2799 TH |
626 | rc = sysfs_add_one(&acxt, sd); |
627 | sysfs_addrm_finish(&acxt); | |
967e35dc | 628 | |
23dc2799 TH |
629 | if (rc == 0) |
630 | *p_sd = sd; | |
631 | else | |
967e35dc | 632 | sysfs_put(sd); |
dfeb9fb0 | 633 | |
23dc2799 | 634 | return rc; |
1da177e4 LT |
635 | } |
636 | ||
608e266a TH |
637 | int sysfs_create_subdir(struct kobject *kobj, const char *name, |
638 | struct sysfs_dirent **p_sd) | |
1da177e4 | 639 | { |
608e266a | 640 | return create_dir(kobj, kobj->sd, name, p_sd); |
1da177e4 LT |
641 | } |
642 | ||
643 | /** | |
644 | * sysfs_create_dir - create a directory for an object. | |
1da177e4 LT |
645 | * @kobj: object we're creating directory for. |
646 | */ | |
90bc6135 | 647 | int sysfs_create_dir(struct kobject * kobj) |
1da177e4 | 648 | { |
608e266a | 649 | struct sysfs_dirent *parent_sd, *sd; |
1da177e4 LT |
650 | int error = 0; |
651 | ||
652 | BUG_ON(!kobj); | |
653 | ||
90bc6135 | 654 | if (kobj->parent) |
608e266a | 655 | parent_sd = kobj->parent->sd; |
1da177e4 | 656 | else |
7d0c7d67 | 657 | parent_sd = &sysfs_root; |
1da177e4 | 658 | |
608e266a | 659 | error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd); |
1da177e4 | 660 | if (!error) |
608e266a | 661 | kobj->sd = sd; |
1da177e4 LT |
662 | return error; |
663 | } | |
664 | ||
1da177e4 LT |
665 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, |
666 | struct nameidata *nd) | |
667 | { | |
6cb52147 | 668 | struct dentry *ret = NULL; |
a7a04754 TH |
669 | struct sysfs_dirent *parent_sd = dentry->d_parent->d_fsdata; |
670 | struct sysfs_dirent *sd; | |
fc9f54b9 | 671 | struct inode *inode; |
1da177e4 | 672 | |
6cb52147 TH |
673 | mutex_lock(&sysfs_mutex); |
674 | ||
94777e09 | 675 | sd = sysfs_find_dirent(parent_sd, dentry->d_name.name); |
1da177e4 | 676 | |
fc9f54b9 | 677 | /* no such entry */ |
e49452c6 TH |
678 | if (!sd) { |
679 | ret = ERR_PTR(-ENOENT); | |
6cb52147 | 680 | goto out_unlock; |
e49452c6 | 681 | } |
fc9f54b9 TH |
682 | |
683 | /* attach dentry and inode */ | |
8312a8d7 | 684 | inode = sysfs_get_inode(sd); |
6cb52147 TH |
685 | if (!inode) { |
686 | ret = ERR_PTR(-ENOMEM); | |
687 | goto out_unlock; | |
688 | } | |
3007e997 | 689 | |
d6b4fd2f | 690 | /* instantiate and hash dentry */ |
832b6af1 EB |
691 | ret = d_find_alias(inode); |
692 | if (!ret) { | |
693 | dentry->d_op = &sysfs_dentry_ops; | |
694 | dentry->d_fsdata = sysfs_get(sd); | |
695 | d_add(dentry, inode); | |
696 | } else { | |
697 | d_move(ret, dentry); | |
698 | iput(inode); | |
699 | } | |
fc9f54b9 | 700 | |
6cb52147 | 701 | out_unlock: |
3007e997 | 702 | mutex_unlock(&sysfs_mutex); |
6cb52147 | 703 | return ret; |
1da177e4 LT |
704 | } |
705 | ||
c5ef1c42 | 706 | const struct inode_operations sysfs_dir_inode_operations = { |
1da177e4 | 707 | .lookup = sysfs_lookup, |
e61ab4ae | 708 | .permission = sysfs_permission, |
988d186d | 709 | .setattr = sysfs_setattr, |
e61ab4ae | 710 | .getattr = sysfs_getattr, |
ddd29ec6 | 711 | .setxattr = sysfs_setxattr, |
1da177e4 LT |
712 | }; |
713 | ||
608e266a | 714 | static void remove_dir(struct sysfs_dirent *sd) |
1da177e4 | 715 | { |
fb6896da | 716 | struct sysfs_addrm_cxt acxt; |
1da177e4 | 717 | |
fb6896da | 718 | sysfs_addrm_start(&acxt, sd->s_parent); |
fb6896da TH |
719 | sysfs_remove_one(&acxt, sd); |
720 | sysfs_addrm_finish(&acxt); | |
1da177e4 LT |
721 | } |
722 | ||
608e266a | 723 | void sysfs_remove_subdir(struct sysfs_dirent *sd) |
1da177e4 | 724 | { |
608e266a | 725 | remove_dir(sd); |
1da177e4 LT |
726 | } |
727 | ||
728 | ||
608e266a | 729 | static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) |
1da177e4 | 730 | { |
fb6896da | 731 | struct sysfs_addrm_cxt acxt; |
0c73f18b | 732 | struct sysfs_dirent **pos; |
1da177e4 | 733 | |
608e266a | 734 | if (!dir_sd) |
1da177e4 LT |
735 | return; |
736 | ||
608e266a | 737 | pr_debug("sysfs %s: removing dir\n", dir_sd->s_name); |
fb6896da | 738 | sysfs_addrm_start(&acxt, dir_sd); |
bc747f37 | 739 | pos = &dir_sd->s_dir.children; |
0c73f18b TH |
740 | while (*pos) { |
741 | struct sysfs_dirent *sd = *pos; | |
742 | ||
3efa65b9 | 743 | if (sysfs_type(sd) != SYSFS_DIR) |
fb6896da | 744 | sysfs_remove_one(&acxt, sd); |
41fc1c27 | 745 | else |
0c73f18b | 746 | pos = &(*pos)->s_sibling; |
1da177e4 | 747 | } |
fb6896da | 748 | sysfs_addrm_finish(&acxt); |
0ab66088 | 749 | |
608e266a | 750 | remove_dir(dir_sd); |
b592fcfe EB |
751 | } |
752 | ||
753 | /** | |
754 | * sysfs_remove_dir - remove an object's directory. | |
755 | * @kobj: object. | |
756 | * | |
757 | * The only thing special about this is that we remove any files in | |
758 | * the directory before we remove the directory, and we've inlined | |
759 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
760 | */ | |
761 | ||
762 | void sysfs_remove_dir(struct kobject * kobj) | |
763 | { | |
608e266a | 764 | struct sysfs_dirent *sd = kobj->sd; |
aecdceda | 765 | |
5f995323 | 766 | spin_lock(&sysfs_assoc_lock); |
608e266a | 767 | kobj->sd = NULL; |
5f995323 | 768 | spin_unlock(&sysfs_assoc_lock); |
aecdceda | 769 | |
608e266a | 770 | __sysfs_remove_dir(sd); |
1da177e4 LT |
771 | } |
772 | ||
ca1bab38 EB |
773 | int sysfs_rename(struct sysfs_dirent *sd, |
774 | struct sysfs_dirent *new_parent_sd, const char *new_name) | |
1da177e4 | 775 | { |
51225039 | 776 | const char *dup_name = NULL; |
996b7376 | 777 | int error; |
1da177e4 | 778 | |
832b6af1 | 779 | mutex_lock(&sysfs_mutex); |
932ea2e3 | 780 | |
9918f9a4 | 781 | error = 0; |
ca1bab38 EB |
782 | if ((sd->s_parent == new_parent_sd) && |
783 | (strcmp(sd->s_name, new_name) == 0)) | |
9918f9a4 EB |
784 | goto out; /* nothing to rename */ |
785 | ||
9918f9a4 | 786 | error = -EEXIST; |
ca1bab38 | 787 | if (sysfs_find_dirent(new_parent_sd, new_name)) |
832b6af1 | 788 | goto out; |
996b7376 | 789 | |
0b4a4fea | 790 | /* rename sysfs_dirent */ |
ca1bab38 EB |
791 | if (strcmp(sd->s_name, new_name) != 0) { |
792 | error = -ENOMEM; | |
793 | new_name = dup_name = kstrdup(new_name, GFP_KERNEL); | |
794 | if (!new_name) | |
795 | goto out; | |
796 | ||
797 | dup_name = sd->s_name; | |
798 | sd->s_name = new_name; | |
799 | } | |
0c096b50 | 800 | |
ca1bab38 EB |
801 | /* Remove from old parent's list and insert into new parent's list. */ |
802 | if (sd->s_parent != new_parent_sd) { | |
803 | sysfs_unlink_sibling(sd); | |
804 | sysfs_get(new_parent_sd); | |
805 | sysfs_put(sd->s_parent); | |
806 | sd->s_parent = new_parent_sd; | |
807 | sysfs_link_sibling(sd); | |
808 | } | |
0c096b50 | 809 | |
996b7376 | 810 | error = 0; |
832b6af1 | 811 | out: |
9918f9a4 | 812 | mutex_unlock(&sysfs_mutex); |
51225039 | 813 | kfree(dup_name); |
1da177e4 LT |
814 | return error; |
815 | } | |
816 | ||
ca1bab38 EB |
817 | int sysfs_rename_dir(struct kobject *kobj, const char *new_name) |
818 | { | |
819 | return sysfs_rename(kobj->sd, kobj->sd->s_parent, new_name); | |
820 | } | |
821 | ||
51225039 | 822 | int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) |
8a82472f | 823 | { |
51225039 TH |
824 | struct sysfs_dirent *sd = kobj->sd; |
825 | struct sysfs_dirent *new_parent_sd; | |
8a82472f | 826 | |
51225039 | 827 | BUG_ON(!sd->s_parent); |
ca1bab38 | 828 | new_parent_sd = new_parent_kobj && new_parent_kobj->sd ? |
a6a83577 | 829 | new_parent_kobj->sd : &sysfs_root; |
51225039 | 830 | |
ca1bab38 | 831 | return sysfs_rename(sd, new_parent_sd, sd->s_name); |
8a82472f CH |
832 | } |
833 | ||
1da177e4 LT |
834 | /* Relationship between s_mode and the DT_xxx types */ |
835 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
836 | { | |
837 | return (sd->s_mode >> 12) & 15; | |
838 | } | |
839 | ||
840 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
841 | { | |
f427f5d5 | 842 | struct dentry *dentry = filp->f_path.dentry; |
1da177e4 | 843 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
3efa65b9 | 844 | struct sysfs_dirent *pos; |
1da177e4 | 845 | ino_t ino; |
1da177e4 | 846 | |
3efa65b9 EB |
847 | if (filp->f_pos == 0) { |
848 | ino = parent_sd->s_ino; | |
849 | if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 850 | filp->f_pos++; |
3efa65b9 EB |
851 | } |
852 | if (filp->f_pos == 1) { | |
853 | if (parent_sd->s_parent) | |
854 | ino = parent_sd->s_parent->s_ino; | |
855 | else | |
856 | ino = parent_sd->s_ino; | |
857 | if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 858 | filp->f_pos++; |
3efa65b9 EB |
859 | } |
860 | if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) { | |
861 | mutex_lock(&sysfs_mutex); | |
0c73f18b | 862 | |
3efa65b9 | 863 | /* Skip the dentries we have already reported */ |
bc747f37 | 864 | pos = parent_sd->s_dir.children; |
3efa65b9 EB |
865 | while (pos && (filp->f_pos > pos->s_ino)) |
866 | pos = pos->s_sibling; | |
3007e997 | 867 | |
3efa65b9 EB |
868 | for ( ; pos; pos = pos->s_sibling) { |
869 | const char * name; | |
870 | int len; | |
1da177e4 | 871 | |
3efa65b9 EB |
872 | name = pos->s_name; |
873 | len = strlen(name); | |
874 | filp->f_pos = ino = pos->s_ino; | |
1da177e4 | 875 | |
3efa65b9 EB |
876 | if (filldir(dirent, name, len, filp->f_pos, ino, |
877 | dt_type(pos)) < 0) | |
1da177e4 | 878 | break; |
1da177e4 | 879 | } |
3efa65b9 EB |
880 | if (!pos) |
881 | filp->f_pos = INT_MAX; | |
3007e997 | 882 | mutex_unlock(&sysfs_mutex); |
1da177e4 | 883 | } |
3efa65b9 | 884 | return 0; |
1da177e4 LT |
885 | } |
886 | ||
3efa65b9 | 887 | |
4b6f5d20 | 888 | const struct file_operations sysfs_dir_operations = { |
1da177e4 LT |
889 | .read = generic_read_dir, |
890 | .readdir = sysfs_readdir, | |
3222a3e5 | 891 | .llseek = generic_file_llseek, |
1da177e4 | 892 | }; |