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); |
0cae60f9 | 29 | DEFINE_SPINLOCK(sysfs_symlink_target_lock); |
1da177e4 | 30 | |
bcac3769 | 31 | #define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb) |
4e4d6d86 | 32 | |
f7a75f0a | 33 | static DEFINE_SPINLOCK(sysfs_ino_lock); |
2b611bb7 TH |
34 | static DEFINE_IDA(sysfs_ino_ida); |
35 | ||
0c73f18b | 36 | /** |
4e4d6d86 | 37 | * sysfs_name_hash |
4e4d6d86 | 38 | * @name: Null terminated string to hash |
cfec0bc8 | 39 | * @ns: Namespace tag to hash |
4e4d6d86 EB |
40 | * |
41 | * Returns 31 bit hash of ns + name (so it fits in an off_t ) | |
42 | */ | |
cfec0bc8 | 43 | static unsigned int sysfs_name_hash(const char *name, const void *ns) |
4e4d6d86 EB |
44 | { |
45 | unsigned long hash = init_name_hash(); | |
46 | unsigned int len = strlen(name); | |
47 | while (len--) | |
48 | hash = partial_name_hash(*name++, hash); | |
1b18dc2b | 49 | hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31)); |
4e4d6d86 EB |
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 | ||
cfec0bc8 TH |
59 | static int sysfs_name_compare(unsigned int hash, const char *name, |
60 | const void *ns, const struct sysfs_dirent *sd) | |
4e4d6d86 EB |
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 | { | |
cfec0bc8 | 72 | return sysfs_name_compare(left->s_hash, left->s_name, left->s_ns, |
4e4d6d86 EB |
73 | right); |
74 | } | |
75 | ||
76 | /** | |
43474910 | 77 | * sysfs_link_sibling - 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 | ||
b6b4a439 TH |
135 | /** |
136 | * sysfs_get_active - get an active reference to sysfs_dirent | |
137 | * @sd: sysfs_dirent to get an active reference to | |
138 | * | |
139 | * Get an active reference of @sd. This function is noop if @sd | |
140 | * is NULL. | |
141 | * | |
142 | * RETURNS: | |
143 | * Pointer to @sd on success, NULL on failure. | |
144 | */ | |
e72ceb8c | 145 | struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) |
b6b4a439 | 146 | { |
8619f979 TH |
147 | if (unlikely(!sd)) |
148 | return NULL; | |
149 | ||
3db3c625 ML |
150 | if (!atomic_inc_unless_negative(&sd->s_active)) |
151 | return NULL; | |
356c05d5 | 152 | |
785a162d | 153 | if (likely(!sysfs_ignore_lockdep(sd))) |
356c05d5 AS |
154 | rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); |
155 | return sd; | |
b6b4a439 TH |
156 | } |
157 | ||
158 | /** | |
159 | * sysfs_put_active - put an active reference to sysfs_dirent | |
160 | * @sd: sysfs_dirent to put an active reference to | |
161 | * | |
162 | * Put an active reference to @sd. This function is noop if @sd | |
163 | * is NULL. | |
164 | */ | |
e72ceb8c | 165 | void sysfs_put_active(struct sysfs_dirent *sd) |
b6b4a439 | 166 | { |
8619f979 TH |
167 | int v; |
168 | ||
169 | if (unlikely(!sd)) | |
170 | return; | |
171 | ||
785a162d | 172 | if (likely(!sysfs_ignore_lockdep(sd))) |
356c05d5 | 173 | rwsem_release(&sd->dep_map, 1, _RET_IP_); |
8619f979 TH |
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 | |
58f2a4c7 | 179 | * sd->u.completion. |
8619f979 | 180 | */ |
58f2a4c7 | 181 | complete(sd->u.completion); |
b6b4a439 TH |
182 | } |
183 | ||
b6b4a439 TH |
184 | /** |
185 | * sysfs_deactivate - deactivate sysfs_dirent | |
186 | * @sd: sysfs_dirent to deactivate | |
187 | * | |
8619f979 | 188 | * Deny new active references and drain existing ones. |
b6b4a439 | 189 | */ |
fb6896da | 190 | static void sysfs_deactivate(struct sysfs_dirent *sd) |
b6b4a439 | 191 | { |
8619f979 TH |
192 | DECLARE_COMPLETION_ONSTACK(wait); |
193 | int v; | |
b6b4a439 | 194 | |
58f2a4c7 | 195 | BUG_ON(!(sd->s_flags & SYSFS_FLAG_REMOVED)); |
a2db6842 EB |
196 | |
197 | if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF)) | |
198 | return; | |
199 | ||
58f2a4c7 | 200 | sd->u.completion = (void *)&wait; |
8619f979 | 201 | |
846f9974 | 202 | rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_); |
8619f979 | 203 | /* atomic_add_return() is a mb(), put_active() will always see |
58f2a4c7 | 204 | * the updated sd->u.completion. |
b6b4a439 | 205 | */ |
8619f979 TH |
206 | v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); |
207 | ||
846f9974 EB |
208 | if (v != SD_DEACTIVATED_BIAS) { |
209 | lock_contended(&sd->dep_map, _RET_IP_); | |
8619f979 | 210 | wait_for_completion(&wait); |
846f9974 | 211 | } |
8619f979 | 212 | |
846f9974 EB |
213 | lock_acquired(&sd->dep_map, _RET_IP_); |
214 | rwsem_release(&sd->dep_map, 1, _RET_IP_); | |
b6b4a439 TH |
215 | } |
216 | ||
cafa6b5d | 217 | static int sysfs_alloc_ino(unsigned int *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 | ||
cafa6b5d | 236 | static void sysfs_free_ino(unsigned int ino) |
2b611bb7 TH |
237 | { |
238 | spin_lock(&sysfs_ino_lock); | |
239 | ida_remove(&sysfs_ino_ida, ino); | |
240 | spin_unlock(&sysfs_ino_lock); | |
241 | } | |
242 | ||
1b18dc2b | 243 | void release_sysfs_dirent(struct sysfs_dirent *sd) |
fa7f912a | 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 | ||
bb2b0051 ML |
253 | WARN(!(sd->s_flags & SYSFS_FLAG_REMOVED), |
254 | "sysfs: free using entry: %s/%s\n", | |
255 | parent_sd ? parent_sd->s_name : "", sd->s_name); | |
256 | ||
b402d72c | 257 | if (sysfs_type(sd) == SYSFS_KOBJ_LINK) |
b1fc3d61 | 258 | sysfs_put(sd->s_symlink.target_sd); |
b402d72c | 259 | if (sysfs_type(sd) & SYSFS_COPY_NAME) |
0c096b50 | 260 | kfree(sd->s_name); |
4c3da220 EB |
261 | if (sd->s_iattr && sd->s_iattr->ia_secdata) |
262 | security_release_secctx(sd->s_iattr->ia_secdata, | |
263 | sd->s_iattr->ia_secdata_len); | |
fa7f912a | 264 | kfree(sd->s_iattr); |
2b611bb7 | 265 | sysfs_free_ino(sd->s_ino); |
fa7f912a | 266 | kmem_cache_free(sysfs_dir_cachep, sd); |
13b3086d TH |
267 | |
268 | sd = parent_sd; | |
269 | if (sd && atomic_dec_and_test(&sd->s_count)) | |
270 | goto repeat; | |
fa7f912a TH |
271 | } |
272 | ||
fe15ce44 | 273 | static int sysfs_dentry_delete(const struct dentry *dentry) |
e8f077c8 EB |
274 | { |
275 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
469796d1 | 276 | return !(sd && !(sd->s_flags & SYSFS_FLAG_REMOVED)); |
e8f077c8 EB |
277 | } |
278 | ||
0b728e19 | 279 | static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags) |
e8f077c8 | 280 | { |
34286d66 | 281 | struct sysfs_dirent *sd; |
e8f077c8 | 282 | |
0b728e19 | 283 | if (flags & LOOKUP_RCU) |
34286d66 NP |
284 | return -ECHILD; |
285 | ||
286 | sd = dentry->d_fsdata; | |
e8f077c8 EB |
287 | mutex_lock(&sysfs_mutex); |
288 | ||
289 | /* The sysfs dirent has been deleted */ | |
290 | if (sd->s_flags & SYSFS_FLAG_REMOVED) | |
291 | goto out_bad; | |
292 | ||
832b6af1 EB |
293 | /* The sysfs dirent has been moved? */ |
294 | if (dentry->d_parent->d_fsdata != sd->s_parent) | |
295 | goto out_bad; | |
296 | ||
297 | /* The sysfs dirent has been renamed */ | |
298 | if (strcmp(dentry->d_name.name, sd->s_name) != 0) | |
299 | goto out_bad; | |
300 | ||
e5bcac61 | 301 | /* The sysfs dirent has been moved to a different namespace */ |
c84a3b27 TH |
302 | if (sd->s_parent && (sd->s_parent->s_flags & SYSFS_FLAG_NS) && |
303 | sysfs_info(dentry->d_sb)->ns != sd->s_ns) | |
304 | goto out_bad; | |
e5bcac61 | 305 | |
e8f077c8 EB |
306 | mutex_unlock(&sysfs_mutex); |
307 | out_valid: | |
308 | return 1; | |
309 | out_bad: | |
310 | /* Remove the dentry from the dcache hashes. | |
311 | * If this is a deleted dentry we use d_drop instead of d_delete | |
312 | * so sysfs doesn't need to cope with negative dentries. | |
832b6af1 EB |
313 | * |
314 | * If this is a dentry that has simply been renamed we | |
315 | * use d_drop to remove it from the dcache lookup on its | |
316 | * old parent. If this dentry persists later when a lookup | |
317 | * is performed at its new name the dentry will be readded | |
318 | * to the dcache hashes. | |
e8f077c8 | 319 | */ |
e8f077c8 | 320 | mutex_unlock(&sysfs_mutex); |
6497d160 MS |
321 | |
322 | /* If we have submounts we must allow the vfs caches | |
323 | * to lie about the state of the filesystem to prevent | |
324 | * leaks and other nasty things. | |
325 | */ | |
326 | if (check_submounts_and_drop(dentry) != 0) | |
327 | goto out_valid; | |
328 | ||
e8f077c8 EB |
329 | return 0; |
330 | } | |
331 | ||
469796d1 | 332 | static void sysfs_dentry_release(struct dentry *dentry) |
1da177e4 | 333 | { |
469796d1 | 334 | sysfs_put(dentry->d_fsdata); |
1da177e4 LT |
335 | } |
336 | ||
469796d1 | 337 | const struct dentry_operations sysfs_dentry_ops = { |
e8f077c8 EB |
338 | .d_revalidate = sysfs_dentry_revalidate, |
339 | .d_delete = sysfs_dentry_delete, | |
469796d1 | 340 | .d_release = sysfs_dentry_release, |
1da177e4 LT |
341 | }; |
342 | ||
3e519038 | 343 | struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) |
1da177e4 | 344 | { |
0c096b50 | 345 | char *dup_name = NULL; |
01da2425 | 346 | struct sysfs_dirent *sd; |
0c096b50 TH |
347 | |
348 | if (type & SYSFS_COPY_NAME) { | |
349 | name = dup_name = kstrdup(name, GFP_KERNEL); | |
350 | if (!name) | |
01da2425 | 351 | return NULL; |
0c096b50 | 352 | } |
1da177e4 | 353 | |
c3762229 | 354 | sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); |
1da177e4 | 355 | if (!sd) |
01da2425 | 356 | goto err_out1; |
1da177e4 | 357 | |
0c096b50 | 358 | if (sysfs_alloc_ino(&sd->s_ino)) |
01da2425 | 359 | goto err_out2; |
2b611bb7 | 360 | |
1da177e4 | 361 | atomic_set(&sd->s_count, 1); |
8619f979 | 362 | atomic_set(&sd->s_active, 0); |
a26cd722 | 363 | |
0c096b50 | 364 | sd->s_name = name; |
a26cd722 | 365 | sd->s_mode = mode; |
bb2b0051 | 366 | sd->s_flags = type | SYSFS_FLAG_REMOVED; |
1da177e4 LT |
367 | |
368 | return sd; | |
0c096b50 | 369 | |
01da2425 | 370 | err_out2: |
0c096b50 | 371 | kmem_cache_free(sysfs_dir_cachep, sd); |
01da2425 AM |
372 | err_out1: |
373 | kfree(dup_name); | |
0c096b50 | 374 | return NULL; |
1da177e4 LT |
375 | } |
376 | ||
3007e997 | 377 | /** |
fb6896da TH |
378 | * sysfs_addrm_start - prepare for sysfs_dirent add/remove |
379 | * @acxt: pointer to sysfs_addrm_cxt to be used | |
3007e997 | 380 | * |
d69ac5a0 TH |
381 | * This function is called when the caller is about to add or remove |
382 | * sysfs_dirent. This function acquires sysfs_mutex. @acxt is used | |
383 | * to keep and pass context to other addrm functions. | |
3007e997 TH |
384 | * |
385 | * LOCKING: | |
fb6896da | 386 | * Kernel thread context (may sleep). sysfs_mutex is locked on |
a16bbc34 | 387 | * return. |
3007e997 | 388 | */ |
d69ac5a0 TH |
389 | void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt) |
390 | __acquires(sysfs_mutex) | |
b592fcfe | 391 | { |
fb6896da | 392 | memset(acxt, 0, sizeof(*acxt)); |
fb6896da | 393 | |
fb6896da | 394 | mutex_lock(&sysfs_mutex); |
fb6896da TH |
395 | } |
396 | ||
397 | /** | |
36ce6dad | 398 | * __sysfs_add_one - add sysfs_dirent to parent without warning |
fb6896da TH |
399 | * @acxt: addrm context to use |
400 | * @sd: sysfs_dirent to be added | |
d69ac5a0 | 401 | * @parent_sd: the parent sysfs_dirent to add @sd to |
fb6896da | 402 | * |
d69ac5a0 TH |
403 | * Get @parent_sd and set @sd->s_parent to it and increment nlink of |
404 | * the parent inode if @sd is a directory and link into the children | |
405 | * list of the parent. | |
fb6896da TH |
406 | * |
407 | * This function should be called between calls to | |
408 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
409 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
410 | * | |
411 | * LOCKING: | |
412 | * Determined by sysfs_addrm_start(). | |
23dc2799 TH |
413 | * |
414 | * RETURNS: | |
415 | * 0 on success, -EEXIST if entry with the given name already | |
416 | * exists. | |
fb6896da | 417 | */ |
d69ac5a0 TH |
418 | int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, |
419 | struct sysfs_dirent *parent_sd) | |
fb6896da | 420 | { |
c84a3b27 | 421 | bool has_ns = parent_sd->s_flags & SYSFS_FLAG_NS; |
6b0bfe93 | 422 | struct sysfs_inode_attrs *ps_iattr; |
4e4d6d86 | 423 | int ret; |
6b0bfe93 | 424 | |
c84a3b27 | 425 | if (has_ns != (bool)sd->s_ns) { |
a1212d27 | 426 | WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", |
c84a3b27 TH |
427 | has_ns ? "required" : "invalid", |
428 | parent_sd->s_name, sd->s_name); | |
a1212d27 LT |
429 | return -EINVAL; |
430 | } | |
431 | ||
ae2108ad TH |
432 | if (sysfs_type(parent_sd) != SYSFS_DIR) |
433 | return -EINVAL; | |
434 | ||
cfec0bc8 | 435 | sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns); |
d69ac5a0 | 436 | sd->s_parent = sysfs_get(parent_sd); |
fb6896da | 437 | |
4e4d6d86 EB |
438 | ret = sysfs_link_sibling(sd); |
439 | if (ret) | |
440 | return ret; | |
23dc2799 | 441 | |
6b0bfe93 | 442 | /* Update timestamps on the parent */ |
d69ac5a0 | 443 | ps_iattr = parent_sd->s_iattr; |
6b0bfe93 EB |
444 | if (ps_iattr) { |
445 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
446 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
447 | } | |
448 | ||
bb2b0051 ML |
449 | /* Mark the entry added into directory tree */ |
450 | sd->s_flags &= ~SYSFS_FLAG_REMOVED; | |
451 | ||
23dc2799 | 452 | return 0; |
fb6896da TH |
453 | } |
454 | ||
425cb029 AC |
455 | /** |
456 | * sysfs_pathname - return full path to sysfs dirent | |
457 | * @sd: sysfs_dirent whose path we want | |
66081a72 | 458 | * @path: caller allocated buffer of size PATH_MAX |
425cb029 AC |
459 | * |
460 | * Gives the name "/" to the sysfs_root entry; any path returned | |
461 | * is relative to wherever sysfs is mounted. | |
425cb029 AC |
462 | */ |
463 | static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) | |
464 | { | |
465 | if (sd->s_parent) { | |
466 | sysfs_pathname(sd->s_parent, path); | |
66081a72 | 467 | strlcat(path, "/", PATH_MAX); |
425cb029 | 468 | } |
66081a72 | 469 | strlcat(path, sd->s_name, PATH_MAX); |
425cb029 AC |
470 | return path; |
471 | } | |
472 | ||
d1c1459e TH |
473 | void sysfs_warn_dup(struct sysfs_dirent *parent, const char *name) |
474 | { | |
475 | char *path; | |
476 | ||
477 | path = kzalloc(PATH_MAX, GFP_KERNEL); | |
478 | if (path) { | |
479 | sysfs_pathname(parent, path); | |
480 | strlcat(path, "/", PATH_MAX); | |
481 | strlcat(path, name, PATH_MAX); | |
482 | } | |
483 | ||
484 | WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s'\n", | |
485 | path ? path : name); | |
486 | ||
487 | kfree(path); | |
488 | } | |
489 | ||
36ce6dad CH |
490 | /** |
491 | * sysfs_add_one - add sysfs_dirent to parent | |
492 | * @acxt: addrm context to use | |
493 | * @sd: sysfs_dirent to be added | |
d69ac5a0 | 494 | * @parent_sd: the parent sysfs_dirent to add @sd to |
36ce6dad | 495 | * |
d69ac5a0 TH |
496 | * Get @parent_sd and set @sd->s_parent to it and increment nlink of |
497 | * the parent inode if @sd is a directory and link into the children | |
498 | * list of the parent. | |
36ce6dad CH |
499 | * |
500 | * This function should be called between calls to | |
501 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
502 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
503 | * | |
504 | * LOCKING: | |
505 | * Determined by sysfs_addrm_start(). | |
506 | * | |
507 | * RETURNS: | |
508 | * 0 on success, -EEXIST if entry with the given name already | |
509 | * exists. | |
510 | */ | |
d69ac5a0 TH |
511 | int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd, |
512 | struct sysfs_dirent *parent_sd) | |
36ce6dad CH |
513 | { |
514 | int ret; | |
515 | ||
d69ac5a0 | 516 | ret = __sysfs_add_one(acxt, sd, parent_sd); |
425cb029 | 517 | |
d1c1459e TH |
518 | if (ret == -EEXIST) |
519 | sysfs_warn_dup(parent_sd, sd->s_name); | |
36ce6dad CH |
520 | return ret; |
521 | } | |
522 | ||
fb6896da TH |
523 | /** |
524 | * sysfs_remove_one - remove sysfs_dirent from parent | |
525 | * @acxt: addrm context to use | |
9fd5b1c9 | 526 | * @sd: sysfs_dirent to be removed |
fb6896da TH |
527 | * |
528 | * Mark @sd removed and drop nlink of parent inode if @sd is a | |
181b2e4b | 529 | * directory. @sd is unlinked from the children list. |
fb6896da TH |
530 | * |
531 | * This function should be called between calls to | |
532 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
533 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
534 | * | |
535 | * LOCKING: | |
536 | * Determined by sysfs_addrm_start(). | |
537 | */ | |
250f7c3f TH |
538 | static void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, |
539 | struct sysfs_dirent *sd) | |
fb6896da | 540 | { |
6b0bfe93 EB |
541 | struct sysfs_inode_attrs *ps_iattr; |
542 | ||
26ea12de TH |
543 | /* |
544 | * Removal can be called multiple times on the same node. Only the | |
545 | * first invocation is effective and puts the base ref. | |
546 | */ | |
547 | if (sd->s_flags & SYSFS_FLAG_REMOVED) | |
548 | return; | |
41fc1c27 TH |
549 | |
550 | sysfs_unlink_sibling(sd); | |
fb6896da | 551 | |
6b0bfe93 | 552 | /* Update timestamps on the parent */ |
d69ac5a0 | 553 | ps_iattr = sd->s_parent->s_iattr; |
6b0bfe93 EB |
554 | if (ps_iattr) { |
555 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
556 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
557 | } | |
558 | ||
fb6896da | 559 | sd->s_flags |= SYSFS_FLAG_REMOVED; |
58f2a4c7 | 560 | sd->u.removed_list = acxt->removed; |
fb6896da | 561 | acxt->removed = sd; |
a0edd7c8 TH |
562 | } |
563 | ||
fb6896da TH |
564 | /** |
565 | * sysfs_addrm_finish - finish up sysfs_dirent add/remove | |
566 | * @acxt: addrm context to finish up | |
567 | * | |
568 | * Finish up sysfs_dirent add/remove. Resources acquired by | |
569 | * sysfs_addrm_start() are released and removed sysfs_dirents are | |
a16bbc34 | 570 | * cleaned up. |
fb6896da TH |
571 | * |
572 | * LOCKING: | |
a16bbc34 | 573 | * sysfs_mutex is released. |
fb6896da | 574 | */ |
990e53f8 | 575 | void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) |
d69ac5a0 | 576 | __releases(sysfs_mutex) |
fb6896da TH |
577 | { |
578 | /* release resources acquired by sysfs_addrm_start() */ | |
579 | mutex_unlock(&sysfs_mutex); | |
fb6896da TH |
580 | |
581 | /* kill removed sysfs_dirents */ | |
582 | while (acxt->removed) { | |
583 | struct sysfs_dirent *sd = acxt->removed; | |
584 | ||
58f2a4c7 | 585 | acxt->removed = sd->u.removed_list; |
fb6896da | 586 | |
fb6896da | 587 | sysfs_deactivate(sd); |
73d97146 | 588 | sysfs_unmap_bin_file(sd); |
fb6896da | 589 | sysfs_put(sd); |
13b3086d | 590 | } |
b592fcfe EB |
591 | } |
592 | ||
f0b0af47 TH |
593 | /** |
594 | * sysfs_find_dirent - find sysfs_dirent with the given name | |
595 | * @parent_sd: sysfs_dirent to search under | |
596 | * @name: name to look for | |
cfec0bc8 | 597 | * @ns: the namespace tag to use |
f0b0af47 TH |
598 | * |
599 | * Look for sysfs_dirent with name @name under @parent_sd. | |
c516865c | 600 | * |
f0b0af47 | 601 | * LOCKING: |
3007e997 | 602 | * mutex_lock(sysfs_mutex) |
c516865c | 603 | * |
f0b0af47 TH |
604 | * RETURNS: |
605 | * Pointer to sysfs_dirent if found, NULL if not. | |
c516865c | 606 | */ |
f0b0af47 | 607 | struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, |
cfec0bc8 TH |
608 | const unsigned char *name, |
609 | const void *ns) | |
c516865c | 610 | { |
4e4d6d86 | 611 | struct rb_node *node = parent_sd->s_dir.children.rb_node; |
c84a3b27 | 612 | bool has_ns = parent_sd->s_flags & SYSFS_FLAG_NS; |
4e4d6d86 | 613 | unsigned int hash; |
4f72c0ca | 614 | |
c84a3b27 | 615 | if (has_ns != (bool)ns) { |
a1212d27 | 616 | WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", |
c84a3b27 TH |
617 | has_ns ? "required" : "invalid", |
618 | parent_sd->s_name, name); | |
a1212d27 LT |
619 | return NULL; |
620 | } | |
621 | ||
cfec0bc8 | 622 | hash = sysfs_name_hash(name, ns); |
4e4d6d86 EB |
623 | while (node) { |
624 | struct sysfs_dirent *sd; | |
625 | int result; | |
626 | ||
627 | sd = to_sysfs_dirent(node); | |
cfec0bc8 | 628 | result = sysfs_name_compare(hash, name, ns, sd); |
4e4d6d86 EB |
629 | if (result < 0) |
630 | node = node->rb_left; | |
631 | else if (result > 0) | |
632 | node = node->rb_right; | |
633 | else | |
634 | return sd; | |
3ff195b0 | 635 | } |
4e4d6d86 | 636 | return NULL; |
f0b0af47 | 637 | } |
c516865c | 638 | |
f0b0af47 | 639 | /** |
388975cc | 640 | * sysfs_get_dirent_ns - find and get sysfs_dirent with the given name |
f0b0af47 TH |
641 | * @parent_sd: sysfs_dirent to search under |
642 | * @name: name to look for | |
388975cc | 643 | * @ns: the namespace tag to use |
f0b0af47 TH |
644 | * |
645 | * Look for sysfs_dirent with name @name under @parent_sd and get | |
646 | * it if found. | |
647 | * | |
648 | * LOCKING: | |
3007e997 | 649 | * Kernel thread context (may sleep). Grabs sysfs_mutex. |
f0b0af47 TH |
650 | * |
651 | * RETURNS: | |
652 | * Pointer to sysfs_dirent if found, NULL if not. | |
653 | */ | |
388975cc TH |
654 | struct sysfs_dirent *sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd, |
655 | const unsigned char *name, | |
656 | const void *ns) | |
f0b0af47 TH |
657 | { |
658 | struct sysfs_dirent *sd; | |
659 | ||
3007e997 | 660 | mutex_lock(&sysfs_mutex); |
cfec0bc8 | 661 | sd = sysfs_find_dirent(parent_sd, name, ns); |
f0b0af47 | 662 | sysfs_get(sd); |
3007e997 | 663 | mutex_unlock(&sysfs_mutex); |
f0b0af47 TH |
664 | |
665 | return sd; | |
c516865c | 666 | } |
388975cc | 667 | EXPORT_SYMBOL_GPL(sysfs_get_dirent_ns); |
c516865c | 668 | |
608e266a | 669 | static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, |
cfec0bc8 TH |
670 | const char *name, const void *ns, |
671 | struct sysfs_dirent **p_sd) | |
1da177e4 | 672 | { |
1b18dc2b | 673 | umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; |
51225039 | 674 | struct sysfs_addrm_cxt acxt; |
dfeb9fb0 | 675 | struct sysfs_dirent *sd; |
23dc2799 | 676 | int rc; |
1da177e4 | 677 | |
fc9f54b9 | 678 | /* allocate */ |
3e519038 | 679 | sd = sysfs_new_dirent(name, mode, SYSFS_DIR); |
a26cd722 | 680 | if (!sd) |
51225039 | 681 | return -ENOMEM; |
3ff195b0 | 682 | |
3ff195b0 | 683 | sd->s_ns = ns; |
7c6e2d36 | 684 | sd->priv = kobj; |
dfeb9fb0 | 685 | |
fc9f54b9 | 686 | /* link in */ |
d69ac5a0 TH |
687 | sysfs_addrm_start(&acxt); |
688 | rc = sysfs_add_one(&acxt, sd, parent_sd); | |
23dc2799 | 689 | sysfs_addrm_finish(&acxt); |
967e35dc | 690 | |
23dc2799 TH |
691 | if (rc == 0) |
692 | *p_sd = sd; | |
693 | else | |
967e35dc | 694 | sysfs_put(sd); |
dfeb9fb0 | 695 | |
23dc2799 | 696 | return rc; |
1da177e4 LT |
697 | } |
698 | ||
608e266a TH |
699 | int sysfs_create_subdir(struct kobject *kobj, const char *name, |
700 | struct sysfs_dirent **p_sd) | |
1da177e4 | 701 | { |
c84a3b27 | 702 | return create_dir(kobj, kobj->sd, name, NULL, p_sd); |
1da177e4 LT |
703 | } |
704 | ||
705 | /** | |
e34ff490 TH |
706 | * sysfs_create_dir_ns - create a directory for an object with a namespace tag |
707 | * @kobj: object we're creating directory for | |
708 | * @ns: the namespace tag to use | |
1da177e4 | 709 | */ |
e34ff490 | 710 | int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) |
1da177e4 | 711 | { |
608e266a | 712 | struct sysfs_dirent *parent_sd, *sd; |
1da177e4 LT |
713 | int error = 0; |
714 | ||
715 | BUG_ON(!kobj); | |
716 | ||
90bc6135 | 717 | if (kobj->parent) |
608e266a | 718 | parent_sd = kobj->parent->sd; |
1da177e4 | 719 | else |
7d0c7d67 | 720 | parent_sd = &sysfs_root; |
1da177e4 | 721 | |
3a198886 DW |
722 | if (!parent_sd) |
723 | return -ENOENT; | |
724 | ||
c84a3b27 | 725 | error = create_dir(kobj, parent_sd, kobject_name(kobj), ns, &sd); |
1da177e4 | 726 | if (!error) |
608e266a | 727 | kobj->sd = sd; |
1da177e4 LT |
728 | return error; |
729 | } | |
730 | ||
1b18dc2b GKH |
731 | static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry, |
732 | unsigned int flags) | |
1da177e4 | 733 | { |
6cb52147 | 734 | struct dentry *ret = NULL; |
3ff195b0 EB |
735 | struct dentry *parent = dentry->d_parent; |
736 | struct sysfs_dirent *parent_sd = parent->d_fsdata; | |
a7a04754 | 737 | struct sysfs_dirent *sd; |
fc9f54b9 | 738 | struct inode *inode; |
c84a3b27 | 739 | const void *ns = NULL; |
1da177e4 | 740 | |
6cb52147 TH |
741 | mutex_lock(&sysfs_mutex); |
742 | ||
c84a3b27 TH |
743 | if (parent_sd->s_flags & SYSFS_FLAG_NS) |
744 | ns = sysfs_info(dir->i_sb)->ns; | |
3ff195b0 | 745 | |
cfec0bc8 | 746 | sd = sysfs_find_dirent(parent_sd, dentry->d_name.name, ns); |
1da177e4 | 747 | |
fc9f54b9 | 748 | /* no such entry */ |
e49452c6 TH |
749 | if (!sd) { |
750 | ret = ERR_PTR(-ENOENT); | |
6cb52147 | 751 | goto out_unlock; |
e49452c6 | 752 | } |
469796d1 | 753 | dentry->d_fsdata = sysfs_get(sd); |
fc9f54b9 TH |
754 | |
755 | /* attach dentry and inode */ | |
fac2622b | 756 | inode = sysfs_get_inode(dir->i_sb, sd); |
6cb52147 TH |
757 | if (!inode) { |
758 | ret = ERR_PTR(-ENOMEM); | |
759 | goto out_unlock; | |
760 | } | |
3007e997 | 761 | |
d6b4fd2f | 762 | /* instantiate and hash dentry */ |
e77fb7ce | 763 | ret = d_materialise_unique(dentry, inode); |
6cb52147 | 764 | out_unlock: |
3007e997 | 765 | mutex_unlock(&sysfs_mutex); |
6cb52147 | 766 | return ret; |
1da177e4 LT |
767 | } |
768 | ||
c5ef1c42 | 769 | const struct inode_operations sysfs_dir_inode_operations = { |
1da177e4 | 770 | .lookup = sysfs_lookup, |
e61ab4ae | 771 | .permission = sysfs_permission, |
988d186d | 772 | .setattr = sysfs_setattr, |
e61ab4ae | 773 | .getattr = sysfs_getattr, |
ddd29ec6 | 774 | .setxattr = sysfs_setxattr, |
1da177e4 LT |
775 | }; |
776 | ||
bcdde7e2 TH |
777 | static struct sysfs_dirent *sysfs_leftmost_descendant(struct sysfs_dirent *pos) |
778 | { | |
779 | struct sysfs_dirent *last; | |
780 | ||
781 | while (true) { | |
782 | struct rb_node *rbn; | |
783 | ||
784 | last = pos; | |
785 | ||
786 | if (sysfs_type(pos) != SYSFS_DIR) | |
787 | break; | |
788 | ||
789 | rbn = rb_first(&pos->s_dir.children); | |
790 | if (!rbn) | |
791 | break; | |
792 | ||
793 | pos = to_sysfs_dirent(rbn); | |
794 | } | |
795 | ||
796 | return last; | |
797 | } | |
798 | ||
799 | /** | |
800 | * sysfs_next_descendant_post - find the next descendant for post-order walk | |
801 | * @pos: the current position (%NULL to initiate traversal) | |
802 | * @root: sysfs_dirent whose descendants to walk | |
803 | * | |
804 | * Find the next descendant to visit for post-order traversal of @root's | |
805 | * descendants. @root is included in the iteration and the last node to be | |
806 | * visited. | |
807 | */ | |
808 | static struct sysfs_dirent *sysfs_next_descendant_post(struct sysfs_dirent *pos, | |
809 | struct sysfs_dirent *root) | |
810 | { | |
811 | struct rb_node *rbn; | |
812 | ||
813 | lockdep_assert_held(&sysfs_mutex); | |
814 | ||
815 | /* if first iteration, visit leftmost descendant which may be root */ | |
816 | if (!pos) | |
817 | return sysfs_leftmost_descendant(root); | |
818 | ||
819 | /* if we visited @root, we're done */ | |
820 | if (pos == root) | |
821 | return NULL; | |
822 | ||
823 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
824 | rbn = rb_next(&pos->s_rb); | |
825 | if (rbn) | |
826 | return sysfs_leftmost_descendant(to_sysfs_dirent(rbn)); | |
827 | ||
828 | /* no sibling left, visit parent */ | |
829 | return pos->s_parent; | |
830 | } | |
1da177e4 | 831 | |
879f40d1 TH |
832 | static void __kernfs_remove(struct sysfs_addrm_cxt *acxt, |
833 | struct sysfs_dirent *sd) | |
1da177e4 | 834 | { |
bcdde7e2 | 835 | struct sysfs_dirent *pos, *next; |
1da177e4 | 836 | |
250f7c3f | 837 | if (!sd) |
1da177e4 LT |
838 | return; |
839 | ||
250f7c3f | 840 | pr_debug("sysfs %s: removing\n", sd->s_name); |
0ab66088 | 841 | |
bcdde7e2 TH |
842 | next = NULL; |
843 | do { | |
844 | pos = next; | |
250f7c3f | 845 | next = sysfs_next_descendant_post(pos, sd); |
bcdde7e2 | 846 | if (pos) |
250f7c3f | 847 | sysfs_remove_one(acxt, pos); |
bcdde7e2 | 848 | } while (next); |
250f7c3f | 849 | } |
bcdde7e2 | 850 | |
250f7c3f | 851 | /** |
879f40d1 | 852 | * kernfs_remove - remove a sysfs_dirent recursively |
250f7c3f TH |
853 | * @sd: the sysfs_dirent to remove |
854 | * | |
855 | * Remove @sd along with all its subdirectories and files. | |
856 | */ | |
879f40d1 | 857 | void kernfs_remove(struct sysfs_dirent *sd) |
250f7c3f TH |
858 | { |
859 | struct sysfs_addrm_cxt acxt; | |
860 | ||
861 | sysfs_addrm_start(&acxt); | |
879f40d1 | 862 | __kernfs_remove(&acxt, sd); |
bcdde7e2 | 863 | sysfs_addrm_finish(&acxt); |
b592fcfe EB |
864 | } |
865 | ||
7eed6ecb | 866 | /** |
879f40d1 | 867 | * kernfs_remove_by_name_ns - find a sysfs_dirent by name and remove it |
7eed6ecb TH |
868 | * @dir_sd: parent of the target |
869 | * @name: name of the sysfs_dirent to remove | |
870 | * @ns: namespace tag of the sysfs_dirent to remove | |
871 | * | |
872 | * Look for the sysfs_dirent with @name and @ns under @dir_sd and remove | |
873 | * it. Returns 0 on success, -ENOENT if such entry doesn't exist. | |
874 | */ | |
879f40d1 TH |
875 | int kernfs_remove_by_name_ns(struct sysfs_dirent *dir_sd, const char *name, |
876 | const void *ns) | |
7eed6ecb TH |
877 | { |
878 | struct sysfs_addrm_cxt acxt; | |
879 | struct sysfs_dirent *sd; | |
880 | ||
881 | if (!dir_sd) { | |
882 | WARN(1, KERN_WARNING "sysfs: can not remove '%s', no directory\n", | |
883 | name); | |
884 | return -ENOENT; | |
885 | } | |
886 | ||
887 | sysfs_addrm_start(&acxt); | |
888 | ||
889 | sd = sysfs_find_dirent(dir_sd, name, ns); | |
890 | if (sd) | |
879f40d1 | 891 | __kernfs_remove(&acxt, sd); |
7eed6ecb TH |
892 | |
893 | sysfs_addrm_finish(&acxt); | |
894 | ||
895 | if (sd) | |
896 | return 0; | |
897 | else | |
898 | return -ENOENT; | |
899 | } | |
900 | ||
b592fcfe EB |
901 | /** |
902 | * sysfs_remove_dir - remove an object's directory. | |
903 | * @kobj: object. | |
904 | * | |
905 | * The only thing special about this is that we remove any files in | |
906 | * the directory before we remove the directory, and we've inlined | |
907 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
908 | */ | |
1b18dc2b | 909 | void sysfs_remove_dir(struct kobject *kobj) |
b592fcfe | 910 | { |
608e266a | 911 | struct sysfs_dirent *sd = kobj->sd; |
aecdceda | 912 | |
0cae60f9 TH |
913 | /* |
914 | * In general, kboject owner is responsible for ensuring removal | |
915 | * doesn't race with other operations and sysfs doesn't provide any | |
916 | * protection; however, when @kobj is used as a symlink target, the | |
917 | * symlinking entity usually doesn't own @kobj and thus has no | |
918 | * control over removal. @kobj->sd may be removed anytime and | |
919 | * symlink code may end up dereferencing an already freed sd. | |
920 | * | |
921 | * sysfs_symlink_target_lock synchronizes @kobj->sd disassociation | |
922 | * against symlink operations so that symlink code can safely | |
923 | * dereference @kobj->sd. | |
924 | */ | |
925 | spin_lock(&sysfs_symlink_target_lock); | |
608e266a | 926 | kobj->sd = NULL; |
0cae60f9 | 927 | spin_unlock(&sysfs_symlink_target_lock); |
aecdceda | 928 | |
250f7c3f TH |
929 | if (sd) { |
930 | WARN_ON_ONCE(sysfs_type(sd) != SYSFS_DIR); | |
879f40d1 | 931 | kernfs_remove(sd); |
250f7c3f | 932 | } |
1da177e4 LT |
933 | } |
934 | ||
890ece16 TH |
935 | /** |
936 | * kernfs_rename_ns - move and rename a kernfs_node | |
937 | * @sd: target node | |
938 | * @new_parent: new parent to put @sd under | |
939 | * @new_name: new name | |
940 | * @new_ns: new namespace tag | |
941 | */ | |
942 | int kernfs_rename_ns(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent, | |
943 | const char *new_name, const void *new_ns) | |
1da177e4 | 944 | { |
996b7376 | 945 | int error; |
1da177e4 | 946 | |
832b6af1 | 947 | mutex_lock(&sysfs_mutex); |
932ea2e3 | 948 | |
9918f9a4 | 949 | error = 0; |
890ece16 | 950 | if ((sd->s_parent == new_parent) && (sd->s_ns == new_ns) && |
ca1bab38 | 951 | (strcmp(sd->s_name, new_name) == 0)) |
9918f9a4 EB |
952 | goto out; /* nothing to rename */ |
953 | ||
9918f9a4 | 954 | error = -EEXIST; |
890ece16 | 955 | if (sysfs_find_dirent(new_parent, new_name, new_ns)) |
832b6af1 | 956 | goto out; |
996b7376 | 957 | |
0b4a4fea | 958 | /* rename sysfs_dirent */ |
ca1bab38 EB |
959 | if (strcmp(sd->s_name, new_name) != 0) { |
960 | error = -ENOMEM; | |
b4eafca1 | 961 | new_name = kstrdup(new_name, GFP_KERNEL); |
ca1bab38 EB |
962 | if (!new_name) |
963 | goto out; | |
964 | ||
b4eafca1 | 965 | kfree(sd->s_name); |
ca1bab38 EB |
966 | sd->s_name = new_name; |
967 | } | |
0c096b50 | 968 | |
ddfd6d07 GKH |
969 | /* |
970 | * Move to the appropriate place in the appropriate directories rbtree. | |
971 | */ | |
f6d90b4f | 972 | sysfs_unlink_sibling(sd); |
890ece16 | 973 | sysfs_get(new_parent); |
f6d90b4f | 974 | sysfs_put(sd->s_parent); |
3ff195b0 | 975 | sd->s_ns = new_ns; |
cfec0bc8 | 976 | sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns); |
890ece16 | 977 | sd->s_parent = new_parent; |
f6d90b4f | 978 | sysfs_link_sibling(sd); |
0c096b50 | 979 | |
996b7376 | 980 | error = 0; |
832b6af1 | 981 | out: |
9918f9a4 | 982 | mutex_unlock(&sysfs_mutex); |
1da177e4 LT |
983 | return error; |
984 | } | |
985 | ||
e34ff490 TH |
986 | int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, |
987 | const void *new_ns) | |
ca1bab38 | 988 | { |
3ff195b0 | 989 | struct sysfs_dirent *parent_sd = kobj->sd->s_parent; |
3ff195b0 | 990 | |
890ece16 | 991 | return kernfs_rename_ns(kobj->sd, parent_sd, new_name, new_ns); |
ca1bab38 EB |
992 | } |
993 | ||
e34ff490 TH |
994 | int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj, |
995 | const void *new_ns) | |
8a82472f | 996 | { |
51225039 TH |
997 | struct sysfs_dirent *sd = kobj->sd; |
998 | struct sysfs_dirent *new_parent_sd; | |
8a82472f | 999 | |
51225039 | 1000 | BUG_ON(!sd->s_parent); |
ca1bab38 | 1001 | new_parent_sd = new_parent_kobj && new_parent_kobj->sd ? |
a6a83577 | 1002 | new_parent_kobj->sd : &sysfs_root; |
51225039 | 1003 | |
890ece16 | 1004 | return kernfs_rename_ns(sd, new_parent_sd, sd->s_name, new_ns); |
8a82472f CH |
1005 | } |
1006 | ||
c84a3b27 TH |
1007 | /** |
1008 | * sysfs_enable_ns - enable namespace under a directory | |
1009 | * @sd: directory of interest, should be empty | |
1010 | * | |
1011 | * This is to be called right after @sd is created to enable namespace | |
1012 | * under it. All children of @sd must have non-NULL namespace tags and | |
1013 | * only the ones which match the super_block's tag will be visible. | |
1014 | */ | |
1015 | void sysfs_enable_ns(struct sysfs_dirent *sd) | |
1016 | { | |
1017 | WARN_ON_ONCE(sysfs_type(sd) != SYSFS_DIR); | |
1018 | WARN_ON_ONCE(!RB_EMPTY_ROOT(&sd->s_dir.children)); | |
1019 | sd->s_flags |= SYSFS_FLAG_NS; | |
1020 | } | |
1021 | ||
1da177e4 LT |
1022 | /* Relationship between s_mode and the DT_xxx types */ |
1023 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
1024 | { | |
1025 | return (sd->s_mode >> 12) & 15; | |
1026 | } | |
1027 | ||
1e5289c9 EB |
1028 | static int sysfs_dir_release(struct inode *inode, struct file *filp) |
1029 | { | |
1030 | sysfs_put(filp->private_data); | |
1031 | return 0; | |
1032 | } | |
1033 | ||
3ff195b0 | 1034 | static struct sysfs_dirent *sysfs_dir_pos(const void *ns, |
4e4d6d86 | 1035 | struct sysfs_dirent *parent_sd, loff_t hash, struct sysfs_dirent *pos) |
1e5289c9 EB |
1036 | { |
1037 | if (pos) { | |
1038 | int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) && | |
1039 | pos->s_parent == parent_sd && | |
4e4d6d86 | 1040 | hash == pos->s_hash; |
1e5289c9 | 1041 | sysfs_put(pos); |
3ff195b0 EB |
1042 | if (!valid) |
1043 | pos = NULL; | |
1e5289c9 | 1044 | } |
4e4d6d86 EB |
1045 | if (!pos && (hash > 1) && (hash < INT_MAX)) { |
1046 | struct rb_node *node = parent_sd->s_dir.children.rb_node; | |
1047 | while (node) { | |
1048 | pos = to_sysfs_dirent(node); | |
1049 | ||
1050 | if (hash < pos->s_hash) | |
1051 | node = node->rb_left; | |
1052 | else if (hash > pos->s_hash) | |
1053 | node = node->rb_right; | |
1054 | else | |
a406f758 | 1055 | break; |
a406f758 MP |
1056 | } |
1057 | } | |
4e4d6d86 | 1058 | /* Skip over entries in the wrong namespace */ |
b9e2780d | 1059 | while (pos && pos->s_ns != ns) { |
4e4d6d86 EB |
1060 | struct rb_node *node = rb_next(&pos->s_rb); |
1061 | if (!node) | |
a406f758 MP |
1062 | pos = NULL; |
1063 | else | |
4e4d6d86 | 1064 | pos = to_sysfs_dirent(node); |
1e5289c9 EB |
1065 | } |
1066 | return pos; | |
1067 | } | |
1068 | ||
3ff195b0 EB |
1069 | static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns, |
1070 | struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos) | |
1e5289c9 | 1071 | { |
3ff195b0 | 1072 | pos = sysfs_dir_pos(ns, parent_sd, ino, pos); |
37814ee0 GKH |
1073 | if (pos) |
1074 | do { | |
1075 | struct rb_node *node = rb_next(&pos->s_rb); | |
1076 | if (!node) | |
1077 | pos = NULL; | |
1078 | else | |
1079 | pos = to_sysfs_dirent(node); | |
1080 | } while (pos && pos->s_ns != ns); | |
1e5289c9 EB |
1081 | return pos; |
1082 | } | |
1083 | ||
d55fea8d | 1084 | static int sysfs_readdir(struct file *file, struct dir_context *ctx) |
1da177e4 | 1085 | { |
d55fea8d | 1086 | struct dentry *dentry = file->f_path.dentry; |
1b18dc2b | 1087 | struct sysfs_dirent *parent_sd = dentry->d_fsdata; |
d55fea8d | 1088 | struct sysfs_dirent *pos = file->private_data; |
c84a3b27 | 1089 | const void *ns = NULL; |
3ff195b0 | 1090 | |
d55fea8d AV |
1091 | if (!dir_emit_dots(file, ctx)) |
1092 | return 0; | |
1e5289c9 | 1093 | mutex_lock(&sysfs_mutex); |
c84a3b27 TH |
1094 | |
1095 | if (parent_sd->s_flags & SYSFS_FLAG_NS) | |
1096 | ns = sysfs_info(dentry->d_sb)->ns; | |
1097 | ||
d55fea8d | 1098 | for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos); |
1e5289c9 | 1099 | pos; |
d55fea8d AV |
1100 | pos = sysfs_dir_next_pos(ns, parent_sd, ctx->pos, pos)) { |
1101 | const char *name = pos->s_name; | |
1102 | unsigned int type = dt_type(pos); | |
1103 | int len = strlen(name); | |
1104 | ino_t ino = pos->s_ino; | |
1105 | ctx->pos = pos->s_hash; | |
1106 | file->private_data = sysfs_get(pos); | |
1da177e4 | 1107 | |
3007e997 | 1108 | mutex_unlock(&sysfs_mutex); |
d55fea8d AV |
1109 | if (!dir_emit(ctx, name, len, ino, type)) |
1110 | return 0; | |
1e5289c9 | 1111 | mutex_lock(&sysfs_mutex); |
1e5289c9 EB |
1112 | } |
1113 | mutex_unlock(&sysfs_mutex); | |
d55fea8d AV |
1114 | file->private_data = NULL; |
1115 | ctx->pos = INT_MAX; | |
3efa65b9 | 1116 | return 0; |
1da177e4 LT |
1117 | } |
1118 | ||
991f76f8 ML |
1119 | static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence) |
1120 | { | |
1121 | struct inode *inode = file_inode(file); | |
1122 | loff_t ret; | |
1123 | ||
1124 | mutex_lock(&inode->i_mutex); | |
1125 | ret = generic_file_llseek(file, offset, whence); | |
1126 | mutex_unlock(&inode->i_mutex); | |
1127 | ||
1128 | return ret; | |
1129 | } | |
3efa65b9 | 1130 | |
4b6f5d20 | 1131 | const struct file_operations sysfs_dir_operations = { |
1da177e4 | 1132 | .read = generic_read_dir, |
d55fea8d | 1133 | .iterate = sysfs_readdir, |
1e5289c9 | 1134 | .release = sysfs_dir_release, |
991f76f8 | 1135 | .llseek = sysfs_dir_llseek, |
1da177e4 | 1136 | }; |