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> |
4e4d6d86 | 25 | #include <linux/hash.h> |
1da177e4 LT |
26 | #include "sysfs.h" |
27 | ||
3007e997 | 28 | DEFINE_MUTEX(sysfs_mutex); |
f7a75f0a | 29 | DEFINE_SPINLOCK(sysfs_assoc_lock); |
1da177e4 | 30 | |
4e4d6d86 EB |
31 | #define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb); |
32 | ||
f7a75f0a | 33 | static DEFINE_SPINLOCK(sysfs_ino_lock); |
2b611bb7 TH |
34 | static DEFINE_IDA(sysfs_ino_ida); |
35 | ||
0c73f18b | 36 | /** |
4e4d6d86 EB |
37 | * sysfs_name_hash |
38 | * @ns: Namespace tag to hash | |
39 | * @name: Null terminated string to hash | |
40 | * | |
41 | * Returns 31 bit hash of ns + name (so it fits in an off_t ) | |
42 | */ | |
43 | static unsigned int sysfs_name_hash(const void *ns, const char *name) | |
44 | { | |
45 | unsigned long hash = init_name_hash(); | |
46 | unsigned int len = strlen(name); | |
47 | while (len--) | |
48 | hash = partial_name_hash(*name++, hash); | |
49 | hash = ( end_name_hash(hash) ^ hash_ptr( (void *)ns, 31 ) ); | |
50 | hash &= 0x7fffffffU; | |
51 | /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ | |
52 | if (hash < 1) | |
53 | hash += 2; | |
54 | if (hash >= INT_MAX) | |
55 | hash = INT_MAX - 1; | |
56 | return hash; | |
57 | } | |
58 | ||
59 | static int sysfs_name_compare(unsigned int hash, const void *ns, | |
60 | const char *name, const struct sysfs_dirent *sd) | |
61 | { | |
62 | if (hash != sd->s_hash) | |
63 | return hash - sd->s_hash; | |
64 | if (ns != sd->s_ns) | |
65 | return ns - sd->s_ns; | |
66 | return strcmp(name, sd->s_name); | |
67 | } | |
68 | ||
69 | static int sysfs_sd_compare(const struct sysfs_dirent *left, | |
70 | const struct sysfs_dirent *right) | |
71 | { | |
72 | return sysfs_name_compare(left->s_hash, left->s_ns, left->s_name, | |
73 | right); | |
74 | } | |
75 | ||
76 | /** | |
77 | * sysfs_link_subling - link sysfs_dirent into sibling rbtree | |
0c73f18b TH |
78 | * @sd: sysfs_dirent of interest |
79 | * | |
4e4d6d86 | 80 | * Link @sd into its sibling rbtree which starts from |
bc747f37 | 81 | * sd->s_parent->s_dir.children. |
0c73f18b TH |
82 | * |
83 | * Locking: | |
3007e997 | 84 | * mutex_lock(sysfs_mutex) |
4e4d6d86 EB |
85 | * |
86 | * RETURNS: | |
87 | * 0 on susccess -EEXIST on failure. | |
0c73f18b | 88 | */ |
4e4d6d86 | 89 | static int sysfs_link_sibling(struct sysfs_dirent *sd) |
0c73f18b | 90 | { |
4e4d6d86 EB |
91 | struct rb_node **node = &sd->s_parent->s_dir.children.rb_node; |
92 | struct rb_node *parent = NULL; | |
4f72c0ca | 93 | |
54d20f00 GKH |
94 | if (sysfs_type(sd) == SYSFS_DIR) |
95 | sd->s_parent->s_dir.subdirs++; | |
96 | ||
4e4d6d86 EB |
97 | while (*node) { |
98 | struct sysfs_dirent *pos; | |
99 | int result; | |
100 | ||
101 | pos = to_sysfs_dirent(*node); | |
102 | parent = *node; | |
103 | result = sysfs_sd_compare(sd, pos); | |
104 | if (result < 0) | |
105 | node = &pos->s_rb.rb_left; | |
106 | else if (result > 0) | |
107 | node = &pos->s_rb.rb_right; | |
108 | else | |
109 | return -EEXIST; | |
4f72c0ca | 110 | } |
4e4d6d86 EB |
111 | /* add new node and rebalance the tree */ |
112 | rb_link_node(&sd->s_rb, parent, node); | |
113 | rb_insert_color(&sd->s_rb, &sd->s_parent->s_dir.children); | |
114 | return 0; | |
0c73f18b TH |
115 | } |
116 | ||
117 | /** | |
4e4d6d86 | 118 | * sysfs_unlink_sibling - unlink sysfs_dirent from sibling rbtree |
0c73f18b TH |
119 | * @sd: sysfs_dirent of interest |
120 | * | |
4e4d6d86 | 121 | * Unlink @sd from its sibling rbtree which starts from |
bc747f37 | 122 | * sd->s_parent->s_dir.children. |
0c73f18b TH |
123 | * |
124 | * Locking: | |
3007e997 | 125 | * mutex_lock(sysfs_mutex) |
0c73f18b | 126 | */ |
41fc1c27 | 127 | static void sysfs_unlink_sibling(struct sysfs_dirent *sd) |
0c73f18b | 128 | { |
54d20f00 GKH |
129 | if (sysfs_type(sd) == SYSFS_DIR) |
130 | sd->s_parent->s_dir.subdirs--; | |
131 | ||
4e4d6d86 | 132 | rb_erase(&sd->s_rb, &sd->s_parent->s_dir.children); |
0c73f18b TH |
133 | } |
134 | ||
356c05d5 AS |
135 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
136 | ||
137 | /* Test for attributes that want to ignore lockdep for read-locking */ | |
138 | static bool ignore_lockdep(struct sysfs_dirent *sd) | |
139 | { | |
140 | return sysfs_type(sd) == SYSFS_KOBJ_ATTR && | |
141 | sd->s_attr.attr->ignore_lockdep; | |
142 | } | |
143 | ||
144 | #else | |
145 | ||
146 | static inline bool ignore_lockdep(struct sysfs_dirent *sd) | |
147 | { | |
148 | return true; | |
149 | } | |
150 | ||
151 | #endif | |
152 | ||
b6b4a439 TH |
153 | /** |
154 | * sysfs_get_active - get an active reference to sysfs_dirent | |
155 | * @sd: sysfs_dirent to get an active reference to | |
156 | * | |
157 | * Get an active reference of @sd. This function is noop if @sd | |
158 | * is NULL. | |
159 | * | |
160 | * RETURNS: | |
161 | * Pointer to @sd on success, NULL on failure. | |
162 | */ | |
e72ceb8c | 163 | struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) |
b6b4a439 | 164 | { |
8619f979 TH |
165 | if (unlikely(!sd)) |
166 | return NULL; | |
167 | ||
168 | while (1) { | |
169 | int v, t; | |
170 | ||
171 | v = atomic_read(&sd->s_active); | |
172 | if (unlikely(v < 0)) | |
173 | return NULL; | |
174 | ||
175 | t = atomic_cmpxchg(&sd->s_active, v, v + 1); | |
356c05d5 AS |
176 | if (likely(t == v)) |
177 | break; | |
8619f979 TH |
178 | if (t < 0) |
179 | return NULL; | |
180 | ||
181 | cpu_relax(); | |
b6b4a439 | 182 | } |
356c05d5 AS |
183 | |
184 | if (likely(!ignore_lockdep(sd))) | |
185 | rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); | |
186 | return sd; | |
b6b4a439 TH |
187 | } |
188 | ||
189 | /** | |
190 | * sysfs_put_active - put an active reference to sysfs_dirent | |
191 | * @sd: sysfs_dirent to put an active reference to | |
192 | * | |
193 | * Put an active reference to @sd. This function is noop if @sd | |
194 | * is NULL. | |
195 | */ | |
e72ceb8c | 196 | void sysfs_put_active(struct sysfs_dirent *sd) |
b6b4a439 | 197 | { |
8619f979 TH |
198 | int v; |
199 | ||
200 | if (unlikely(!sd)) | |
201 | return; | |
202 | ||
356c05d5 AS |
203 | if (likely(!ignore_lockdep(sd))) |
204 | rwsem_release(&sd->dep_map, 1, _RET_IP_); | |
8619f979 TH |
205 | v = atomic_dec_return(&sd->s_active); |
206 | if (likely(v != SD_DEACTIVATED_BIAS)) | |
207 | return; | |
208 | ||
209 | /* atomic_dec_return() is a mb(), we'll always see the updated | |
58f2a4c7 | 210 | * sd->u.completion. |
8619f979 | 211 | */ |
58f2a4c7 | 212 | complete(sd->u.completion); |
b6b4a439 TH |
213 | } |
214 | ||
b6b4a439 TH |
215 | /** |
216 | * sysfs_deactivate - deactivate sysfs_dirent | |
217 | * @sd: sysfs_dirent to deactivate | |
218 | * | |
8619f979 | 219 | * Deny new active references and drain existing ones. |
b6b4a439 | 220 | */ |
fb6896da | 221 | static void sysfs_deactivate(struct sysfs_dirent *sd) |
b6b4a439 | 222 | { |
8619f979 TH |
223 | DECLARE_COMPLETION_ONSTACK(wait); |
224 | int v; | |
b6b4a439 | 225 | |
58f2a4c7 | 226 | BUG_ON(!(sd->s_flags & SYSFS_FLAG_REMOVED)); |
a2db6842 EB |
227 | |
228 | if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF)) | |
229 | return; | |
230 | ||
58f2a4c7 | 231 | sd->u.completion = (void *)&wait; |
8619f979 | 232 | |
846f9974 | 233 | rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_); |
8619f979 | 234 | /* atomic_add_return() is a mb(), put_active() will always see |
58f2a4c7 | 235 | * the updated sd->u.completion. |
b6b4a439 | 236 | */ |
8619f979 TH |
237 | v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); |
238 | ||
846f9974 EB |
239 | if (v != SD_DEACTIVATED_BIAS) { |
240 | lock_contended(&sd->dep_map, _RET_IP_); | |
8619f979 | 241 | wait_for_completion(&wait); |
846f9974 | 242 | } |
8619f979 | 243 | |
846f9974 EB |
244 | lock_acquired(&sd->dep_map, _RET_IP_); |
245 | rwsem_release(&sd->dep_map, 1, _RET_IP_); | |
b6b4a439 TH |
246 | } |
247 | ||
cafa6b5d | 248 | static int sysfs_alloc_ino(unsigned int *pino) |
2b611bb7 TH |
249 | { |
250 | int ino, rc; | |
251 | ||
252 | retry: | |
253 | spin_lock(&sysfs_ino_lock); | |
254 | rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino); | |
255 | spin_unlock(&sysfs_ino_lock); | |
256 | ||
257 | if (rc == -EAGAIN) { | |
258 | if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL)) | |
259 | goto retry; | |
260 | rc = -ENOMEM; | |
261 | } | |
262 | ||
263 | *pino = ino; | |
264 | return rc; | |
265 | } | |
266 | ||
cafa6b5d | 267 | static void sysfs_free_ino(unsigned int ino) |
2b611bb7 TH |
268 | { |
269 | spin_lock(&sysfs_ino_lock); | |
270 | ida_remove(&sysfs_ino_ida, ino); | |
271 | spin_unlock(&sysfs_ino_lock); | |
272 | } | |
273 | ||
fa7f912a TH |
274 | void release_sysfs_dirent(struct sysfs_dirent * sd) |
275 | { | |
13b3086d TH |
276 | struct sysfs_dirent *parent_sd; |
277 | ||
278 | repeat: | |
3007e997 TH |
279 | /* Moving/renaming is always done while holding reference. |
280 | * sd->s_parent won't change beneath us. | |
281 | */ | |
13b3086d TH |
282 | parent_sd = sd->s_parent; |
283 | ||
b402d72c | 284 | if (sysfs_type(sd) == SYSFS_KOBJ_LINK) |
b1fc3d61 | 285 | sysfs_put(sd->s_symlink.target_sd); |
b402d72c | 286 | if (sysfs_type(sd) & SYSFS_COPY_NAME) |
0c096b50 | 287 | kfree(sd->s_name); |
4c3da220 EB |
288 | if (sd->s_iattr && sd->s_iattr->ia_secdata) |
289 | security_release_secctx(sd->s_iattr->ia_secdata, | |
290 | sd->s_iattr->ia_secdata_len); | |
fa7f912a | 291 | kfree(sd->s_iattr); |
2b611bb7 | 292 | sysfs_free_ino(sd->s_ino); |
fa7f912a | 293 | kmem_cache_free(sysfs_dir_cachep, sd); |
13b3086d TH |
294 | |
295 | sd = parent_sd; | |
296 | if (sd && atomic_dec_and_test(&sd->s_count)) | |
297 | goto repeat; | |
fa7f912a TH |
298 | } |
299 | ||
fe15ce44 | 300 | static int sysfs_dentry_delete(const struct dentry *dentry) |
e8f077c8 EB |
301 | { |
302 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
469796d1 | 303 | return !(sd && !(sd->s_flags & SYSFS_FLAG_REMOVED)); |
e8f077c8 EB |
304 | } |
305 | ||
0b728e19 | 306 | static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags) |
e8f077c8 | 307 | { |
34286d66 | 308 | struct sysfs_dirent *sd; |
e8f077c8 | 309 | int is_dir; |
e5bcac61 | 310 | int type; |
e8f077c8 | 311 | |
0b728e19 | 312 | if (flags & LOOKUP_RCU) |
34286d66 NP |
313 | return -ECHILD; |
314 | ||
315 | sd = dentry->d_fsdata; | |
e8f077c8 EB |
316 | mutex_lock(&sysfs_mutex); |
317 | ||
318 | /* The sysfs dirent has been deleted */ | |
319 | if (sd->s_flags & SYSFS_FLAG_REMOVED) | |
320 | goto out_bad; | |
321 | ||
832b6af1 EB |
322 | /* The sysfs dirent has been moved? */ |
323 | if (dentry->d_parent->d_fsdata != sd->s_parent) | |
324 | goto out_bad; | |
325 | ||
326 | /* The sysfs dirent has been renamed */ | |
327 | if (strcmp(dentry->d_name.name, sd->s_name) != 0) | |
328 | goto out_bad; | |
329 | ||
e5bcac61 GC |
330 | /* The sysfs dirent has been moved to a different namespace */ |
331 | type = KOBJ_NS_TYPE_NONE; | |
17f79be9 | 332 | if (sd->s_parent) { |
e5bcac61 | 333 | type = sysfs_ns_type(sd->s_parent); |
17f79be9 AM |
334 | if (type != KOBJ_NS_TYPE_NONE && |
335 | sysfs_info(dentry->d_sb)->ns[type] != sd->s_ns) | |
336 | goto out_bad; | |
337 | } | |
e5bcac61 | 338 | |
e8f077c8 EB |
339 | mutex_unlock(&sysfs_mutex); |
340 | out_valid: | |
341 | return 1; | |
342 | out_bad: | |
343 | /* Remove the dentry from the dcache hashes. | |
344 | * If this is a deleted dentry we use d_drop instead of d_delete | |
345 | * so sysfs doesn't need to cope with negative dentries. | |
832b6af1 EB |
346 | * |
347 | * If this is a dentry that has simply been renamed we | |
348 | * use d_drop to remove it from the dcache lookup on its | |
349 | * old parent. If this dentry persists later when a lookup | |
350 | * is performed at its new name the dentry will be readded | |
351 | * to the dcache hashes. | |
e8f077c8 EB |
352 | */ |
353 | is_dir = (sysfs_type(sd) == SYSFS_DIR); | |
354 | mutex_unlock(&sysfs_mutex); | |
355 | if (is_dir) { | |
356 | /* If we have submounts we must allow the vfs caches | |
357 | * to lie about the state of the filesystem to prevent | |
358 | * leaks and other nasty things. | |
359 | */ | |
360 | if (have_submounts(dentry)) | |
361 | goto out_valid; | |
362 | shrink_dcache_parent(dentry); | |
363 | } | |
364 | d_drop(dentry); | |
365 | return 0; | |
366 | } | |
367 | ||
469796d1 | 368 | static void sysfs_dentry_release(struct dentry *dentry) |
1da177e4 | 369 | { |
469796d1 | 370 | sysfs_put(dentry->d_fsdata); |
1da177e4 LT |
371 | } |
372 | ||
469796d1 | 373 | const struct dentry_operations sysfs_dentry_ops = { |
e8f077c8 EB |
374 | .d_revalidate = sysfs_dentry_revalidate, |
375 | .d_delete = sysfs_dentry_delete, | |
469796d1 | 376 | .d_release = sysfs_dentry_release, |
1da177e4 LT |
377 | }; |
378 | ||
3e519038 | 379 | struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) |
1da177e4 | 380 | { |
0c096b50 | 381 | char *dup_name = NULL; |
01da2425 | 382 | struct sysfs_dirent *sd; |
0c096b50 TH |
383 | |
384 | if (type & SYSFS_COPY_NAME) { | |
385 | name = dup_name = kstrdup(name, GFP_KERNEL); | |
386 | if (!name) | |
01da2425 | 387 | return NULL; |
0c096b50 | 388 | } |
1da177e4 | 389 | |
c3762229 | 390 | sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); |
1da177e4 | 391 | if (!sd) |
01da2425 | 392 | goto err_out1; |
1da177e4 | 393 | |
0c096b50 | 394 | if (sysfs_alloc_ino(&sd->s_ino)) |
01da2425 | 395 | goto err_out2; |
2b611bb7 | 396 | |
1da177e4 | 397 | atomic_set(&sd->s_count, 1); |
8619f979 | 398 | atomic_set(&sd->s_active, 0); |
a26cd722 | 399 | |
0c096b50 | 400 | sd->s_name = name; |
a26cd722 | 401 | sd->s_mode = mode; |
b402d72c | 402 | sd->s_flags = type; |
1da177e4 LT |
403 | |
404 | return sd; | |
0c096b50 | 405 | |
01da2425 | 406 | err_out2: |
0c096b50 | 407 | kmem_cache_free(sysfs_dir_cachep, sd); |
01da2425 AM |
408 | err_out1: |
409 | kfree(dup_name); | |
0c096b50 | 410 | return NULL; |
1da177e4 LT |
411 | } |
412 | ||
3007e997 | 413 | /** |
fb6896da TH |
414 | * sysfs_addrm_start - prepare for sysfs_dirent add/remove |
415 | * @acxt: pointer to sysfs_addrm_cxt to be used | |
416 | * @parent_sd: parent sysfs_dirent | |
3007e997 | 417 | * |
fb6896da TH |
418 | * This function is called when the caller is about to add or |
419 | * remove sysfs_dirent under @parent_sd. This function acquires | |
a16bbc34 | 420 | * sysfs_mutex. @acxt is used to keep and pass context to |
fb6896da | 421 | * other addrm functions. |
3007e997 TH |
422 | * |
423 | * LOCKING: | |
fb6896da | 424 | * Kernel thread context (may sleep). sysfs_mutex is locked on |
a16bbc34 | 425 | * return. |
3007e997 | 426 | */ |
fb6896da TH |
427 | void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, |
428 | struct sysfs_dirent *parent_sd) | |
b592fcfe | 429 | { |
fb6896da TH |
430 | memset(acxt, 0, sizeof(*acxt)); |
431 | acxt->parent_sd = parent_sd; | |
432 | ||
fb6896da | 433 | mutex_lock(&sysfs_mutex); |
fb6896da TH |
434 | } |
435 | ||
436 | /** | |
36ce6dad | 437 | * __sysfs_add_one - add sysfs_dirent to parent without warning |
fb6896da TH |
438 | * @acxt: addrm context to use |
439 | * @sd: sysfs_dirent to be added | |
440 | * | |
441 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
181b2e4b TH |
442 | * nlink of parent inode if @sd is a directory and link into the |
443 | * children list of the parent. | |
fb6896da TH |
444 | * |
445 | * This function should be called between calls to | |
446 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
447 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
448 | * | |
449 | * LOCKING: | |
450 | * Determined by sysfs_addrm_start(). | |
23dc2799 TH |
451 | * |
452 | * RETURNS: | |
453 | * 0 on success, -EEXIST if entry with the given name already | |
454 | * exists. | |
fb6896da | 455 | */ |
36ce6dad | 456 | int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) |
fb6896da | 457 | { |
6b0bfe93 | 458 | struct sysfs_inode_attrs *ps_iattr; |
4e4d6d86 | 459 | int ret; |
6b0bfe93 | 460 | |
903e21e2 EB |
461 | if (!!sysfs_ns_type(acxt->parent_sd) != !!sd->s_ns) { |
462 | WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", | |
463 | sysfs_ns_type(acxt->parent_sd)? "required": "invalid", | |
464 | acxt->parent_sd->s_name, sd->s_name); | |
465 | return -EINVAL; | |
466 | } | |
467 | ||
4e4d6d86 | 468 | sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name); |
fb6896da TH |
469 | sd->s_parent = sysfs_get(acxt->parent_sd); |
470 | ||
4e4d6d86 EB |
471 | ret = sysfs_link_sibling(sd); |
472 | if (ret) | |
473 | return ret; | |
23dc2799 | 474 | |
6b0bfe93 EB |
475 | /* Update timestamps on the parent */ |
476 | ps_iattr = acxt->parent_sd->s_iattr; | |
477 | if (ps_iattr) { | |
478 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
479 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
480 | } | |
481 | ||
23dc2799 | 482 | return 0; |
fb6896da TH |
483 | } |
484 | ||
425cb029 AC |
485 | /** |
486 | * sysfs_pathname - return full path to sysfs dirent | |
487 | * @sd: sysfs_dirent whose path we want | |
488 | * @path: caller allocated buffer | |
489 | * | |
490 | * Gives the name "/" to the sysfs_root entry; any path returned | |
491 | * is relative to wherever sysfs is mounted. | |
492 | * | |
493 | * XXX: does no error checking on @path size | |
494 | */ | |
495 | static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) | |
496 | { | |
497 | if (sd->s_parent) { | |
498 | sysfs_pathname(sd->s_parent, path); | |
499 | strcat(path, "/"); | |
500 | } | |
501 | strcat(path, sd->s_name); | |
502 | return path; | |
503 | } | |
504 | ||
36ce6dad CH |
505 | /** |
506 | * sysfs_add_one - add sysfs_dirent to parent | |
507 | * @acxt: addrm context to use | |
508 | * @sd: sysfs_dirent to be added | |
509 | * | |
510 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
511 | * nlink of parent inode if @sd is a directory and link into the | |
512 | * children list of the parent. | |
513 | * | |
514 | * This function should be called between calls to | |
515 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
516 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
517 | * | |
518 | * LOCKING: | |
519 | * Determined by sysfs_addrm_start(). | |
520 | * | |
521 | * RETURNS: | |
522 | * 0 on success, -EEXIST if entry with the given name already | |
523 | * exists. | |
524 | */ | |
525 | int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
526 | { | |
527 | int ret; | |
528 | ||
529 | ret = __sysfs_add_one(acxt, sd); | |
425cb029 AC |
530 | if (ret == -EEXIST) { |
531 | char *path = kzalloc(PATH_MAX, GFP_KERNEL); | |
532 | WARN(1, KERN_WARNING | |
533 | "sysfs: cannot create duplicate filename '%s'\n", | |
534 | (path == NULL) ? sd->s_name : | |
535 | strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"), | |
536 | sd->s_name)); | |
537 | kfree(path); | |
538 | } | |
539 | ||
36ce6dad CH |
540 | return ret; |
541 | } | |
542 | ||
fb6896da TH |
543 | /** |
544 | * sysfs_remove_one - remove sysfs_dirent from parent | |
545 | * @acxt: addrm context to use | |
9fd5b1c9 | 546 | * @sd: sysfs_dirent to be removed |
fb6896da TH |
547 | * |
548 | * Mark @sd removed and drop nlink of parent inode if @sd is a | |
181b2e4b | 549 | * directory. @sd is unlinked from the children list. |
fb6896da TH |
550 | * |
551 | * This function should be called between calls to | |
552 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
553 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
554 | * | |
555 | * LOCKING: | |
556 | * Determined by sysfs_addrm_start(). | |
557 | */ | |
558 | void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
559 | { | |
6b0bfe93 EB |
560 | struct sysfs_inode_attrs *ps_iattr; |
561 | ||
41fc1c27 TH |
562 | BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED); |
563 | ||
564 | sysfs_unlink_sibling(sd); | |
fb6896da | 565 | |
6b0bfe93 EB |
566 | /* Update timestamps on the parent */ |
567 | ps_iattr = acxt->parent_sd->s_iattr; | |
568 | if (ps_iattr) { | |
569 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
570 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
571 | } | |
572 | ||
fb6896da | 573 | sd->s_flags |= SYSFS_FLAG_REMOVED; |
58f2a4c7 | 574 | sd->u.removed_list = acxt->removed; |
fb6896da | 575 | acxt->removed = sd; |
a0edd7c8 TH |
576 | } |
577 | ||
fb6896da TH |
578 | /** |
579 | * sysfs_addrm_finish - finish up sysfs_dirent add/remove | |
580 | * @acxt: addrm context to finish up | |
581 | * | |
582 | * Finish up sysfs_dirent add/remove. Resources acquired by | |
583 | * sysfs_addrm_start() are released and removed sysfs_dirents are | |
a16bbc34 | 584 | * cleaned up. |
fb6896da TH |
585 | * |
586 | * LOCKING: | |
a16bbc34 | 587 | * sysfs_mutex is released. |
fb6896da | 588 | */ |
990e53f8 | 589 | void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) |
fb6896da TH |
590 | { |
591 | /* release resources acquired by sysfs_addrm_start() */ | |
592 | mutex_unlock(&sysfs_mutex); | |
fb6896da TH |
593 | |
594 | /* kill removed sysfs_dirents */ | |
595 | while (acxt->removed) { | |
596 | struct sysfs_dirent *sd = acxt->removed; | |
597 | ||
58f2a4c7 | 598 | acxt->removed = sd->u.removed_list; |
fb6896da | 599 | |
fb6896da | 600 | sysfs_deactivate(sd); |
e0edd3c6 | 601 | unmap_bin_file(sd); |
fb6896da | 602 | sysfs_put(sd); |
13b3086d | 603 | } |
b592fcfe EB |
604 | } |
605 | ||
f0b0af47 TH |
606 | /** |
607 | * sysfs_find_dirent - find sysfs_dirent with the given name | |
608 | * @parent_sd: sysfs_dirent to search under | |
609 | * @name: name to look for | |
610 | * | |
611 | * Look for sysfs_dirent with name @name under @parent_sd. | |
c516865c | 612 | * |
f0b0af47 | 613 | * LOCKING: |
3007e997 | 614 | * mutex_lock(sysfs_mutex) |
c516865c | 615 | * |
f0b0af47 TH |
616 | * RETURNS: |
617 | * Pointer to sysfs_dirent if found, NULL if not. | |
c516865c | 618 | */ |
f0b0af47 | 619 | struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, |
3ff195b0 | 620 | const void *ns, |
f0b0af47 | 621 | const unsigned char *name) |
c516865c | 622 | { |
4e4d6d86 EB |
623 | struct rb_node *node = parent_sd->s_dir.children.rb_node; |
624 | unsigned int hash; | |
4f72c0ca | 625 | |
903e21e2 EB |
626 | if (!!sysfs_ns_type(parent_sd) != !!ns) { |
627 | WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", | |
628 | sysfs_ns_type(parent_sd)? "required": "invalid", | |
629 | parent_sd->s_name, name); | |
630 | return NULL; | |
631 | } | |
632 | ||
4e4d6d86 EB |
633 | hash = sysfs_name_hash(ns, name); |
634 | while (node) { | |
635 | struct sysfs_dirent *sd; | |
636 | int result; | |
637 | ||
638 | sd = to_sysfs_dirent(node); | |
639 | result = sysfs_name_compare(hash, ns, name, sd); | |
640 | if (result < 0) | |
641 | node = node->rb_left; | |
642 | else if (result > 0) | |
643 | node = node->rb_right; | |
644 | else | |
645 | return sd; | |
3ff195b0 | 646 | } |
4e4d6d86 | 647 | return NULL; |
f0b0af47 | 648 | } |
c516865c | 649 | |
f0b0af47 TH |
650 | /** |
651 | * sysfs_get_dirent - find and get sysfs_dirent with the given name | |
652 | * @parent_sd: sysfs_dirent to search under | |
653 | * @name: name to look for | |
654 | * | |
655 | * Look for sysfs_dirent with name @name under @parent_sd and get | |
656 | * it if found. | |
657 | * | |
658 | * LOCKING: | |
3007e997 | 659 | * Kernel thread context (may sleep). Grabs sysfs_mutex. |
f0b0af47 TH |
660 | * |
661 | * RETURNS: | |
662 | * Pointer to sysfs_dirent if found, NULL if not. | |
663 | */ | |
664 | struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, | |
3ff195b0 | 665 | const void *ns, |
f0b0af47 TH |
666 | const unsigned char *name) |
667 | { | |
668 | struct sysfs_dirent *sd; | |
669 | ||
3007e997 | 670 | mutex_lock(&sysfs_mutex); |
3ff195b0 | 671 | sd = sysfs_find_dirent(parent_sd, ns, name); |
f0b0af47 | 672 | sysfs_get(sd); |
3007e997 | 673 | mutex_unlock(&sysfs_mutex); |
f0b0af47 TH |
674 | |
675 | return sd; | |
c516865c | 676 | } |
f1282c84 | 677 | EXPORT_SYMBOL_GPL(sysfs_get_dirent); |
c516865c | 678 | |
608e266a | 679 | static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, |
3ff195b0 EB |
680 | enum kobj_ns_type type, const void *ns, const char *name, |
681 | struct sysfs_dirent **p_sd) | |
1da177e4 | 682 | { |
1da177e4 | 683 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; |
51225039 | 684 | struct sysfs_addrm_cxt acxt; |
dfeb9fb0 | 685 | struct sysfs_dirent *sd; |
23dc2799 | 686 | int rc; |
1da177e4 | 687 | |
fc9f54b9 | 688 | /* allocate */ |
3e519038 | 689 | sd = sysfs_new_dirent(name, mode, SYSFS_DIR); |
a26cd722 | 690 | if (!sd) |
51225039 | 691 | return -ENOMEM; |
3ff195b0 EB |
692 | |
693 | sd->s_flags |= (type << SYSFS_NS_TYPE_SHIFT); | |
694 | sd->s_ns = ns; | |
b1fc3d61 | 695 | sd->s_dir.kobj = kobj; |
dfeb9fb0 | 696 | |
fc9f54b9 | 697 | /* link in */ |
51225039 | 698 | sysfs_addrm_start(&acxt, parent_sd); |
23dc2799 TH |
699 | rc = sysfs_add_one(&acxt, sd); |
700 | sysfs_addrm_finish(&acxt); | |
967e35dc | 701 | |
23dc2799 TH |
702 | if (rc == 0) |
703 | *p_sd = sd; | |
704 | else | |
967e35dc | 705 | sysfs_put(sd); |
dfeb9fb0 | 706 | |
23dc2799 | 707 | return rc; |
1da177e4 LT |
708 | } |
709 | ||
608e266a TH |
710 | int sysfs_create_subdir(struct kobject *kobj, const char *name, |
711 | struct sysfs_dirent **p_sd) | |
1da177e4 | 712 | { |
3ff195b0 EB |
713 | return create_dir(kobj, kobj->sd, |
714 | KOBJ_NS_TYPE_NONE, NULL, name, p_sd); | |
715 | } | |
716 | ||
be867b19 SH |
717 | /** |
718 | * sysfs_read_ns_type: return associated ns_type | |
719 | * @kobj: the kobject being queried | |
720 | * | |
721 | * Each kobject can be tagged with exactly one namespace type | |
722 | * (i.e. network or user). Return the ns_type associated with | |
723 | * this object if any | |
724 | */ | |
3ff195b0 EB |
725 | static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj) |
726 | { | |
727 | const struct kobj_ns_type_operations *ops; | |
728 | enum kobj_ns_type type; | |
729 | ||
730 | ops = kobj_child_ns_ops(kobj); | |
731 | if (!ops) | |
732 | return KOBJ_NS_TYPE_NONE; | |
733 | ||
734 | type = ops->type; | |
735 | BUG_ON(type <= KOBJ_NS_TYPE_NONE); | |
736 | BUG_ON(type >= KOBJ_NS_TYPES); | |
737 | BUG_ON(!kobj_ns_type_registered(type)); | |
738 | ||
739 | return type; | |
1da177e4 LT |
740 | } |
741 | ||
742 | /** | |
743 | * sysfs_create_dir - create a directory for an object. | |
1da177e4 LT |
744 | * @kobj: object we're creating directory for. |
745 | */ | |
90bc6135 | 746 | int sysfs_create_dir(struct kobject * kobj) |
1da177e4 | 747 | { |
3ff195b0 | 748 | enum kobj_ns_type type; |
608e266a | 749 | struct sysfs_dirent *parent_sd, *sd; |
3ff195b0 | 750 | const void *ns = NULL; |
1da177e4 LT |
751 | int error = 0; |
752 | ||
753 | BUG_ON(!kobj); | |
754 | ||
90bc6135 | 755 | if (kobj->parent) |
608e266a | 756 | parent_sd = kobj->parent->sd; |
1da177e4 | 757 | else |
7d0c7d67 | 758 | parent_sd = &sysfs_root; |
1da177e4 | 759 | |
3a198886 DW |
760 | if (!parent_sd) |
761 | return -ENOENT; | |
762 | ||
3ff195b0 EB |
763 | if (sysfs_ns_type(parent_sd)) |
764 | ns = kobj->ktype->namespace(kobj); | |
765 | type = sysfs_read_ns_type(kobj); | |
766 | ||
767 | error = create_dir(kobj, parent_sd, type, ns, kobject_name(kobj), &sd); | |
1da177e4 | 768 | if (!error) |
608e266a | 769 | kobj->sd = sd; |
1da177e4 LT |
770 | return error; |
771 | } | |
772 | ||
1da177e4 | 773 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, |
00cd8dd3 | 774 | unsigned int flags) |
1da177e4 | 775 | { |
6cb52147 | 776 | struct dentry *ret = NULL; |
3ff195b0 EB |
777 | struct dentry *parent = dentry->d_parent; |
778 | struct sysfs_dirent *parent_sd = parent->d_fsdata; | |
a7a04754 | 779 | struct sysfs_dirent *sd; |
fc9f54b9 | 780 | struct inode *inode; |
3ff195b0 EB |
781 | enum kobj_ns_type type; |
782 | const void *ns; | |
1da177e4 | 783 | |
6cb52147 TH |
784 | mutex_lock(&sysfs_mutex); |
785 | ||
3ff195b0 EB |
786 | type = sysfs_ns_type(parent_sd); |
787 | ns = sysfs_info(dir->i_sb)->ns[type]; | |
788 | ||
789 | sd = sysfs_find_dirent(parent_sd, ns, dentry->d_name.name); | |
1da177e4 | 790 | |
fc9f54b9 | 791 | /* no such entry */ |
e49452c6 TH |
792 | if (!sd) { |
793 | ret = ERR_PTR(-ENOENT); | |
6cb52147 | 794 | goto out_unlock; |
e49452c6 | 795 | } |
469796d1 | 796 | dentry->d_fsdata = sysfs_get(sd); |
fc9f54b9 TH |
797 | |
798 | /* attach dentry and inode */ | |
fac2622b | 799 | inode = sysfs_get_inode(dir->i_sb, sd); |
6cb52147 TH |
800 | if (!inode) { |
801 | ret = ERR_PTR(-ENOMEM); | |
802 | goto out_unlock; | |
803 | } | |
3007e997 | 804 | |
d6b4fd2f | 805 | /* instantiate and hash dentry */ |
e77fb7ce | 806 | ret = d_materialise_unique(dentry, inode); |
6cb52147 | 807 | out_unlock: |
3007e997 | 808 | mutex_unlock(&sysfs_mutex); |
6cb52147 | 809 | return ret; |
1da177e4 LT |
810 | } |
811 | ||
c5ef1c42 | 812 | const struct inode_operations sysfs_dir_inode_operations = { |
1da177e4 | 813 | .lookup = sysfs_lookup, |
e61ab4ae | 814 | .permission = sysfs_permission, |
988d186d | 815 | .setattr = sysfs_setattr, |
e61ab4ae | 816 | .getattr = sysfs_getattr, |
ddd29ec6 | 817 | .setxattr = sysfs_setxattr, |
1da177e4 LT |
818 | }; |
819 | ||
608e266a | 820 | static void remove_dir(struct sysfs_dirent *sd) |
1da177e4 | 821 | { |
fb6896da | 822 | struct sysfs_addrm_cxt acxt; |
1da177e4 | 823 | |
fb6896da | 824 | sysfs_addrm_start(&acxt, sd->s_parent); |
fb6896da TH |
825 | sysfs_remove_one(&acxt, sd); |
826 | sysfs_addrm_finish(&acxt); | |
1da177e4 LT |
827 | } |
828 | ||
608e266a | 829 | void sysfs_remove_subdir(struct sysfs_dirent *sd) |
1da177e4 | 830 | { |
608e266a | 831 | remove_dir(sd); |
1da177e4 LT |
832 | } |
833 | ||
834 | ||
608e266a | 835 | static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) |
1da177e4 | 836 | { |
fb6896da | 837 | struct sysfs_addrm_cxt acxt; |
a406f758 | 838 | struct rb_node *pos; |
1da177e4 | 839 | |
608e266a | 840 | if (!dir_sd) |
1da177e4 LT |
841 | return; |
842 | ||
608e266a | 843 | pr_debug("sysfs %s: removing dir\n", dir_sd->s_name); |
fb6896da | 844 | sysfs_addrm_start(&acxt, dir_sd); |
4e4d6d86 | 845 | pos = rb_first(&dir_sd->s_dir.children); |
a406f758 | 846 | while (pos) { |
4e4d6d86 | 847 | struct sysfs_dirent *sd = to_sysfs_dirent(pos); |
a406f758 | 848 | pos = rb_next(pos); |
3efa65b9 | 849 | if (sysfs_type(sd) != SYSFS_DIR) |
fb6896da | 850 | sysfs_remove_one(&acxt, sd); |
1da177e4 | 851 | } |
fb6896da | 852 | sysfs_addrm_finish(&acxt); |
0ab66088 | 853 | |
608e266a | 854 | remove_dir(dir_sd); |
b592fcfe EB |
855 | } |
856 | ||
857 | /** | |
858 | * sysfs_remove_dir - remove an object's directory. | |
859 | * @kobj: object. | |
860 | * | |
861 | * The only thing special about this is that we remove any files in | |
862 | * the directory before we remove the directory, and we've inlined | |
863 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
864 | */ | |
865 | ||
866 | void sysfs_remove_dir(struct kobject * kobj) | |
867 | { | |
608e266a | 868 | struct sysfs_dirent *sd = kobj->sd; |
aecdceda | 869 | |
5f995323 | 870 | spin_lock(&sysfs_assoc_lock); |
608e266a | 871 | kobj->sd = NULL; |
5f995323 | 872 | spin_unlock(&sysfs_assoc_lock); |
aecdceda | 873 | |
608e266a | 874 | __sysfs_remove_dir(sd); |
1da177e4 LT |
875 | } |
876 | ||
ca1bab38 | 877 | int sysfs_rename(struct sysfs_dirent *sd, |
3ff195b0 EB |
878 | struct sysfs_dirent *new_parent_sd, const void *new_ns, |
879 | const char *new_name) | |
1da177e4 | 880 | { |
996b7376 | 881 | int error; |
1da177e4 | 882 | |
832b6af1 | 883 | mutex_lock(&sysfs_mutex); |
932ea2e3 | 884 | |
9918f9a4 | 885 | error = 0; |
3ff195b0 | 886 | if ((sd->s_parent == new_parent_sd) && (sd->s_ns == new_ns) && |
ca1bab38 | 887 | (strcmp(sd->s_name, new_name) == 0)) |
9918f9a4 EB |
888 | goto out; /* nothing to rename */ |
889 | ||
9918f9a4 | 890 | error = -EEXIST; |
3ff195b0 | 891 | if (sysfs_find_dirent(new_parent_sd, new_ns, new_name)) |
832b6af1 | 892 | goto out; |
996b7376 | 893 | |
0b4a4fea | 894 | /* rename sysfs_dirent */ |
ca1bab38 EB |
895 | if (strcmp(sd->s_name, new_name) != 0) { |
896 | error = -ENOMEM; | |
b4eafca1 | 897 | new_name = kstrdup(new_name, GFP_KERNEL); |
ca1bab38 EB |
898 | if (!new_name) |
899 | goto out; | |
900 | ||
b4eafca1 | 901 | kfree(sd->s_name); |
ca1bab38 EB |
902 | sd->s_name = new_name; |
903 | } | |
0c096b50 | 904 | |
f6d90b4f EB |
905 | /* Move to the appropriate place in the appropriate directories rbtree. */ |
906 | sysfs_unlink_sibling(sd); | |
907 | sysfs_get(new_parent_sd); | |
908 | sysfs_put(sd->s_parent); | |
3ff195b0 | 909 | sd->s_ns = new_ns; |
70fa4a62 | 910 | sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name); |
f6d90b4f EB |
911 | sd->s_parent = new_parent_sd; |
912 | sysfs_link_sibling(sd); | |
0c096b50 | 913 | |
996b7376 | 914 | error = 0; |
832b6af1 | 915 | out: |
9918f9a4 | 916 | mutex_unlock(&sysfs_mutex); |
1da177e4 LT |
917 | return error; |
918 | } | |
919 | ||
ca1bab38 EB |
920 | int sysfs_rename_dir(struct kobject *kobj, const char *new_name) |
921 | { | |
3ff195b0 EB |
922 | struct sysfs_dirent *parent_sd = kobj->sd->s_parent; |
923 | const void *new_ns = NULL; | |
924 | ||
925 | if (sysfs_ns_type(parent_sd)) | |
926 | new_ns = kobj->ktype->namespace(kobj); | |
927 | ||
928 | return sysfs_rename(kobj->sd, parent_sd, new_ns, new_name); | |
ca1bab38 EB |
929 | } |
930 | ||
51225039 | 931 | int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) |
8a82472f | 932 | { |
51225039 TH |
933 | struct sysfs_dirent *sd = kobj->sd; |
934 | struct sysfs_dirent *new_parent_sd; | |
3ff195b0 | 935 | const void *new_ns = NULL; |
8a82472f | 936 | |
51225039 | 937 | BUG_ON(!sd->s_parent); |
3ff195b0 EB |
938 | if (sysfs_ns_type(sd->s_parent)) |
939 | new_ns = kobj->ktype->namespace(kobj); | |
ca1bab38 | 940 | new_parent_sd = new_parent_kobj && new_parent_kobj->sd ? |
a6a83577 | 941 | new_parent_kobj->sd : &sysfs_root; |
51225039 | 942 | |
3ff195b0 | 943 | return sysfs_rename(sd, new_parent_sd, new_ns, sd->s_name); |
8a82472f CH |
944 | } |
945 | ||
1da177e4 LT |
946 | /* Relationship between s_mode and the DT_xxx types */ |
947 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
948 | { | |
949 | return (sd->s_mode >> 12) & 15; | |
950 | } | |
951 | ||
1e5289c9 EB |
952 | static int sysfs_dir_release(struct inode *inode, struct file *filp) |
953 | { | |
954 | sysfs_put(filp->private_data); | |
955 | return 0; | |
956 | } | |
957 | ||
3ff195b0 | 958 | static struct sysfs_dirent *sysfs_dir_pos(const void *ns, |
4e4d6d86 | 959 | struct sysfs_dirent *parent_sd, loff_t hash, struct sysfs_dirent *pos) |
1e5289c9 EB |
960 | { |
961 | if (pos) { | |
962 | int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) && | |
963 | pos->s_parent == parent_sd && | |
4e4d6d86 | 964 | hash == pos->s_hash; |
1e5289c9 | 965 | sysfs_put(pos); |
3ff195b0 EB |
966 | if (!valid) |
967 | pos = NULL; | |
1e5289c9 | 968 | } |
4e4d6d86 EB |
969 | if (!pos && (hash > 1) && (hash < INT_MAX)) { |
970 | struct rb_node *node = parent_sd->s_dir.children.rb_node; | |
971 | while (node) { | |
972 | pos = to_sysfs_dirent(node); | |
973 | ||
974 | if (hash < pos->s_hash) | |
975 | node = node->rb_left; | |
976 | else if (hash > pos->s_hash) | |
977 | node = node->rb_right; | |
978 | else | |
a406f758 | 979 | break; |
a406f758 MP |
980 | } |
981 | } | |
4e4d6d86 | 982 | /* Skip over entries in the wrong namespace */ |
b9e2780d | 983 | while (pos && pos->s_ns != ns) { |
4e4d6d86 EB |
984 | struct rb_node *node = rb_next(&pos->s_rb); |
985 | if (!node) | |
a406f758 MP |
986 | pos = NULL; |
987 | else | |
4e4d6d86 | 988 | pos = to_sysfs_dirent(node); |
1e5289c9 EB |
989 | } |
990 | return pos; | |
991 | } | |
992 | ||
3ff195b0 EB |
993 | static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns, |
994 | struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos) | |
1e5289c9 | 995 | { |
3ff195b0 | 996 | pos = sysfs_dir_pos(ns, parent_sd, ino, pos); |
a406f758 | 997 | if (pos) do { |
4e4d6d86 EB |
998 | struct rb_node *node = rb_next(&pos->s_rb); |
999 | if (!node) | |
a406f758 MP |
1000 | pos = NULL; |
1001 | else | |
4e4d6d86 | 1002 | pos = to_sysfs_dirent(node); |
b9e2780d | 1003 | } while (pos && pos->s_ns != ns); |
1e5289c9 EB |
1004 | return pos; |
1005 | } | |
1006 | ||
1da177e4 LT |
1007 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) |
1008 | { | |
f427f5d5 | 1009 | struct dentry *dentry = filp->f_path.dentry; |
1da177e4 | 1010 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
1e5289c9 | 1011 | struct sysfs_dirent *pos = filp->private_data; |
3ff195b0 EB |
1012 | enum kobj_ns_type type; |
1013 | const void *ns; | |
1da177e4 | 1014 | ino_t ino; |
1da177e4 | 1015 | |
3ff195b0 EB |
1016 | type = sysfs_ns_type(parent_sd); |
1017 | ns = sysfs_info(dentry->d_sb)->ns[type]; | |
1018 | ||
3efa65b9 EB |
1019 | if (filp->f_pos == 0) { |
1020 | ino = parent_sd->s_ino; | |
1021 | if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 1022 | filp->f_pos++; |
3efa65b9 EB |
1023 | } |
1024 | if (filp->f_pos == 1) { | |
1025 | if (parent_sd->s_parent) | |
1026 | ino = parent_sd->s_parent->s_ino; | |
1027 | else | |
1028 | ino = parent_sd->s_ino; | |
1029 | if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 1030 | filp->f_pos++; |
3efa65b9 | 1031 | } |
1e5289c9 | 1032 | mutex_lock(&sysfs_mutex); |
3ff195b0 | 1033 | for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos); |
1e5289c9 | 1034 | pos; |
3ff195b0 | 1035 | pos = sysfs_dir_next_pos(ns, parent_sd, filp->f_pos, pos)) { |
1e5289c9 EB |
1036 | const char * name; |
1037 | unsigned int type; | |
1038 | int len, ret; | |
1039 | ||
1040 | name = pos->s_name; | |
1041 | len = strlen(name); | |
1042 | ino = pos->s_ino; | |
1043 | type = dt_type(pos); | |
4e4d6d86 | 1044 | filp->f_pos = pos->s_hash; |
1e5289c9 | 1045 | filp->private_data = sysfs_get(pos); |
1da177e4 | 1046 | |
3007e997 | 1047 | mutex_unlock(&sysfs_mutex); |
1e5289c9 EB |
1048 | ret = filldir(dirent, name, len, filp->f_pos, ino, type); |
1049 | mutex_lock(&sysfs_mutex); | |
1050 | if (ret < 0) | |
1051 | break; | |
1052 | } | |
1053 | mutex_unlock(&sysfs_mutex); | |
1054 | if ((filp->f_pos > 1) && !pos) { /* EOF */ | |
1055 | filp->f_pos = INT_MAX; | |
1056 | filp->private_data = NULL; | |
1da177e4 | 1057 | } |
3efa65b9 | 1058 | return 0; |
1da177e4 LT |
1059 | } |
1060 | ||
3efa65b9 | 1061 | |
4b6f5d20 | 1062 | const struct file_operations sysfs_dir_operations = { |
1da177e4 LT |
1063 | .read = generic_read_dir, |
1064 | .readdir = sysfs_readdir, | |
1e5289c9 | 1065 | .release = sysfs_dir_release, |
3222a3e5 | 1066 | .llseek = generic_file_llseek, |
1da177e4 | 1067 | }; |