Commit | Line | Data |
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b8441ed2 TH |
1 | /* |
2 | * fs/kernfs/dir.c - kernfs directory implementation | |
3 | * | |
4 | * Copyright (c) 2001-3 Patrick Mochel | |
5 | * Copyright (c) 2007 SUSE Linux Products GmbH | |
6 | * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org> | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | */ | |
fd7b9f7b TH |
10 | |
11 | #include <linux/fs.h> | |
12 | #include <linux/namei.h> | |
13 | #include <linux/idr.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/security.h> | |
16 | #include <linux/hash.h> | |
17 | ||
18 | #include "kernfs-internal.h" | |
19 | ||
20 | DEFINE_MUTEX(sysfs_mutex); | |
21 | ||
324a56e1 | 22 | #define rb_to_kn(X) rb_entry((X), struct kernfs_node, s_rb) |
fd7b9f7b | 23 | |
fd7b9f7b TH |
24 | /** |
25 | * sysfs_name_hash | |
26 | * @name: Null terminated string to hash | |
27 | * @ns: Namespace tag to hash | |
28 | * | |
29 | * Returns 31 bit hash of ns + name (so it fits in an off_t ) | |
30 | */ | |
31 | static unsigned int sysfs_name_hash(const char *name, const void *ns) | |
32 | { | |
33 | unsigned long hash = init_name_hash(); | |
34 | unsigned int len = strlen(name); | |
35 | while (len--) | |
36 | hash = partial_name_hash(*name++, hash); | |
37 | hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31)); | |
38 | hash &= 0x7fffffffU; | |
39 | /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ | |
40 | if (hash < 1) | |
41 | hash += 2; | |
42 | if (hash >= INT_MAX) | |
43 | hash = INT_MAX - 1; | |
44 | return hash; | |
45 | } | |
46 | ||
47 | static int sysfs_name_compare(unsigned int hash, const char *name, | |
324a56e1 | 48 | const void *ns, const struct kernfs_node *kn) |
fd7b9f7b | 49 | { |
324a56e1 TH |
50 | if (hash != kn->s_hash) |
51 | return hash - kn->s_hash; | |
52 | if (ns != kn->s_ns) | |
53 | return ns - kn->s_ns; | |
54 | return strcmp(name, kn->s_name); | |
fd7b9f7b TH |
55 | } |
56 | ||
324a56e1 TH |
57 | static int sysfs_sd_compare(const struct kernfs_node *left, |
58 | const struct kernfs_node *right) | |
fd7b9f7b TH |
59 | { |
60 | return sysfs_name_compare(left->s_hash, left->s_name, left->s_ns, | |
61 | right); | |
62 | } | |
63 | ||
64 | /** | |
324a56e1 TH |
65 | * sysfs_link_sibling - link kernfs_node into sibling rbtree |
66 | * @kn: kernfs_node of interest | |
fd7b9f7b | 67 | * |
324a56e1 TH |
68 | * Link @kn into its sibling rbtree which starts from |
69 | * @kn->s_parent->s_dir.children. | |
fd7b9f7b TH |
70 | * |
71 | * Locking: | |
72 | * mutex_lock(sysfs_mutex) | |
73 | * | |
74 | * RETURNS: | |
75 | * 0 on susccess -EEXIST on failure. | |
76 | */ | |
324a56e1 | 77 | static int sysfs_link_sibling(struct kernfs_node *kn) |
fd7b9f7b | 78 | { |
324a56e1 | 79 | struct rb_node **node = &kn->s_parent->s_dir.children.rb_node; |
fd7b9f7b TH |
80 | struct rb_node *parent = NULL; |
81 | ||
324a56e1 TH |
82 | if (sysfs_type(kn) == SYSFS_DIR) |
83 | kn->s_parent->s_dir.subdirs++; | |
fd7b9f7b TH |
84 | |
85 | while (*node) { | |
324a56e1 | 86 | struct kernfs_node *pos; |
fd7b9f7b TH |
87 | int result; |
88 | ||
324a56e1 | 89 | pos = rb_to_kn(*node); |
fd7b9f7b | 90 | parent = *node; |
324a56e1 | 91 | result = sysfs_sd_compare(kn, pos); |
fd7b9f7b TH |
92 | if (result < 0) |
93 | node = &pos->s_rb.rb_left; | |
94 | else if (result > 0) | |
95 | node = &pos->s_rb.rb_right; | |
96 | else | |
97 | return -EEXIST; | |
98 | } | |
99 | /* add new node and rebalance the tree */ | |
324a56e1 TH |
100 | rb_link_node(&kn->s_rb, parent, node); |
101 | rb_insert_color(&kn->s_rb, &kn->s_parent->s_dir.children); | |
fd7b9f7b TH |
102 | return 0; |
103 | } | |
104 | ||
105 | /** | |
324a56e1 TH |
106 | * sysfs_unlink_sibling - unlink kernfs_node from sibling rbtree |
107 | * @kn: kernfs_node of interest | |
fd7b9f7b | 108 | * |
324a56e1 TH |
109 | * Unlink @kn from its sibling rbtree which starts from |
110 | * kn->s_parent->s_dir.children. | |
fd7b9f7b TH |
111 | * |
112 | * Locking: | |
113 | * mutex_lock(sysfs_mutex) | |
114 | */ | |
324a56e1 | 115 | static void sysfs_unlink_sibling(struct kernfs_node *kn) |
fd7b9f7b | 116 | { |
324a56e1 TH |
117 | if (sysfs_type(kn) == SYSFS_DIR) |
118 | kn->s_parent->s_dir.subdirs--; | |
fd7b9f7b | 119 | |
324a56e1 | 120 | rb_erase(&kn->s_rb, &kn->s_parent->s_dir.children); |
fd7b9f7b TH |
121 | } |
122 | ||
123 | /** | |
324a56e1 TH |
124 | * sysfs_get_active - get an active reference to kernfs_node |
125 | * @kn: kernfs_node to get an active reference to | |
fd7b9f7b | 126 | * |
324a56e1 | 127 | * Get an active reference of @kn. This function is noop if @kn |
fd7b9f7b TH |
128 | * is NULL. |
129 | * | |
130 | * RETURNS: | |
324a56e1 | 131 | * Pointer to @kn on success, NULL on failure. |
fd7b9f7b | 132 | */ |
324a56e1 | 133 | struct kernfs_node *sysfs_get_active(struct kernfs_node *kn) |
fd7b9f7b | 134 | { |
324a56e1 | 135 | if (unlikely(!kn)) |
fd7b9f7b TH |
136 | return NULL; |
137 | ||
324a56e1 | 138 | if (!atomic_inc_unless_negative(&kn->s_active)) |
fd7b9f7b TH |
139 | return NULL; |
140 | ||
324a56e1 TH |
141 | if (kn->s_flags & SYSFS_FLAG_LOCKDEP) |
142 | rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_); | |
143 | return kn; | |
fd7b9f7b TH |
144 | } |
145 | ||
146 | /** | |
324a56e1 TH |
147 | * sysfs_put_active - put an active reference to kernfs_node |
148 | * @kn: kernfs_node to put an active reference to | |
fd7b9f7b | 149 | * |
324a56e1 | 150 | * Put an active reference to @kn. This function is noop if @kn |
fd7b9f7b TH |
151 | * is NULL. |
152 | */ | |
324a56e1 | 153 | void sysfs_put_active(struct kernfs_node *kn) |
fd7b9f7b TH |
154 | { |
155 | int v; | |
156 | ||
324a56e1 | 157 | if (unlikely(!kn)) |
fd7b9f7b TH |
158 | return; |
159 | ||
324a56e1 TH |
160 | if (kn->s_flags & SYSFS_FLAG_LOCKDEP) |
161 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
162 | v = atomic_dec_return(&kn->s_active); | |
fd7b9f7b TH |
163 | if (likely(v != SD_DEACTIVATED_BIAS)) |
164 | return; | |
165 | ||
324a56e1 TH |
166 | /* |
167 | * atomic_dec_return() is a mb(), we'll always see the updated | |
168 | * kn->u.completion. | |
fd7b9f7b | 169 | */ |
324a56e1 | 170 | complete(kn->u.completion); |
fd7b9f7b TH |
171 | } |
172 | ||
173 | /** | |
324a56e1 TH |
174 | * sysfs_deactivate - deactivate kernfs_node |
175 | * @kn: kernfs_node to deactivate | |
fd7b9f7b TH |
176 | * |
177 | * Deny new active references and drain existing ones. | |
178 | */ | |
324a56e1 | 179 | static void sysfs_deactivate(struct kernfs_node *kn) |
fd7b9f7b TH |
180 | { |
181 | DECLARE_COMPLETION_ONSTACK(wait); | |
182 | int v; | |
183 | ||
324a56e1 | 184 | BUG_ON(!(kn->s_flags & SYSFS_FLAG_REMOVED)); |
fd7b9f7b | 185 | |
324a56e1 | 186 | if (!(sysfs_type(kn) & SYSFS_ACTIVE_REF)) |
fd7b9f7b TH |
187 | return; |
188 | ||
324a56e1 | 189 | kn->u.completion = (void *)&wait; |
fd7b9f7b | 190 | |
324a56e1 | 191 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); |
fd7b9f7b | 192 | /* atomic_add_return() is a mb(), put_active() will always see |
324a56e1 | 193 | * the updated kn->u.completion. |
fd7b9f7b | 194 | */ |
324a56e1 | 195 | v = atomic_add_return(SD_DEACTIVATED_BIAS, &kn->s_active); |
fd7b9f7b TH |
196 | |
197 | if (v != SD_DEACTIVATED_BIAS) { | |
324a56e1 | 198 | lock_contended(&kn->dep_map, _RET_IP_); |
fd7b9f7b TH |
199 | wait_for_completion(&wait); |
200 | } | |
201 | ||
324a56e1 TH |
202 | lock_acquired(&kn->dep_map, _RET_IP_); |
203 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
fd7b9f7b TH |
204 | } |
205 | ||
fd7b9f7b | 206 | /** |
324a56e1 TH |
207 | * kernfs_get - get a reference count on a kernfs_node |
208 | * @kn: the target kernfs_node | |
fd7b9f7b | 209 | */ |
324a56e1 | 210 | void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b | 211 | { |
324a56e1 TH |
212 | if (kn) { |
213 | WARN_ON(!atomic_read(&kn->s_count)); | |
214 | atomic_inc(&kn->s_count); | |
fd7b9f7b TH |
215 | } |
216 | } | |
217 | EXPORT_SYMBOL_GPL(kernfs_get); | |
218 | ||
219 | /** | |
324a56e1 TH |
220 | * kernfs_put - put a reference count on a kernfs_node |
221 | * @kn: the target kernfs_node | |
fd7b9f7b | 222 | * |
324a56e1 | 223 | * Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b | 224 | */ |
324a56e1 | 225 | void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b | 226 | { |
324a56e1 | 227 | struct kernfs_node *parent; |
ba7443bc | 228 | struct kernfs_root *root; |
fd7b9f7b | 229 | |
324a56e1 | 230 | if (!kn || !atomic_dec_and_test(&kn->s_count)) |
fd7b9f7b | 231 | return; |
324a56e1 | 232 | root = kernfs_root(kn); |
fd7b9f7b TH |
233 | repeat: |
234 | /* Moving/renaming is always done while holding reference. | |
324a56e1 | 235 | * kn->s_parent won't change beneath us. |
fd7b9f7b | 236 | */ |
324a56e1 | 237 | parent = kn->s_parent; |
fd7b9f7b | 238 | |
324a56e1 | 239 | WARN(!(kn->s_flags & SYSFS_FLAG_REMOVED), |
fd7b9f7b | 240 | "sysfs: free using entry: %s/%s\n", |
324a56e1 TH |
241 | parent ? parent->s_name : "", kn->s_name); |
242 | ||
243 | if (sysfs_type(kn) == SYSFS_KOBJ_LINK) | |
244 | kernfs_put(kn->s_symlink.target_kn); | |
245 | if (sysfs_type(kn) & SYSFS_COPY_NAME) | |
246 | kfree(kn->s_name); | |
247 | if (kn->s_iattr) { | |
248 | if (kn->s_iattr->ia_secdata) | |
249 | security_release_secctx(kn->s_iattr->ia_secdata, | |
250 | kn->s_iattr->ia_secdata_len); | |
251 | simple_xattrs_free(&kn->s_iattr->xattrs); | |
2322392b | 252 | } |
324a56e1 TH |
253 | kfree(kn->s_iattr); |
254 | ida_simple_remove(&root->ino_ida, kn->s_ino); | |
255 | kmem_cache_free(sysfs_dir_cachep, kn); | |
fd7b9f7b | 256 | |
324a56e1 TH |
257 | kn = parent; |
258 | if (kn) { | |
259 | if (atomic_dec_and_test(&kn->s_count)) | |
ba7443bc TH |
260 | goto repeat; |
261 | } else { | |
324a56e1 | 262 | /* just released the root kn, free @root too */ |
bc755553 | 263 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
264 | kfree(root); |
265 | } | |
fd7b9f7b TH |
266 | } |
267 | EXPORT_SYMBOL_GPL(kernfs_put); | |
268 | ||
269 | static int sysfs_dentry_delete(const struct dentry *dentry) | |
270 | { | |
324a56e1 TH |
271 | struct kernfs_node *kn = dentry->d_fsdata; |
272 | return !(kn && !(kn->s_flags & SYSFS_FLAG_REMOVED)); | |
fd7b9f7b TH |
273 | } |
274 | ||
275 | static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags) | |
276 | { | |
324a56e1 | 277 | struct kernfs_node *kn; |
fd7b9f7b TH |
278 | |
279 | if (flags & LOOKUP_RCU) | |
280 | return -ECHILD; | |
281 | ||
324a56e1 | 282 | kn = dentry->d_fsdata; |
fd7b9f7b TH |
283 | mutex_lock(&sysfs_mutex); |
284 | ||
285 | /* The sysfs dirent has been deleted */ | |
324a56e1 | 286 | if (kn->s_flags & SYSFS_FLAG_REMOVED) |
fd7b9f7b TH |
287 | goto out_bad; |
288 | ||
289 | /* The sysfs dirent has been moved? */ | |
324a56e1 | 290 | if (dentry->d_parent->d_fsdata != kn->s_parent) |
fd7b9f7b TH |
291 | goto out_bad; |
292 | ||
293 | /* The sysfs dirent has been renamed */ | |
324a56e1 | 294 | if (strcmp(dentry->d_name.name, kn->s_name) != 0) |
fd7b9f7b TH |
295 | goto out_bad; |
296 | ||
297 | /* The sysfs dirent has been moved to a different namespace */ | |
324a56e1 TH |
298 | if (kn->s_parent && kernfs_ns_enabled(kn->s_parent) && |
299 | sysfs_info(dentry->d_sb)->ns != kn->s_ns) | |
fd7b9f7b TH |
300 | goto out_bad; |
301 | ||
302 | mutex_unlock(&sysfs_mutex); | |
303 | out_valid: | |
304 | return 1; | |
305 | out_bad: | |
306 | /* Remove the dentry from the dcache hashes. | |
307 | * If this is a deleted dentry we use d_drop instead of d_delete | |
308 | * so sysfs doesn't need to cope with negative dentries. | |
309 | * | |
310 | * If this is a dentry that has simply been renamed we | |
311 | * use d_drop to remove it from the dcache lookup on its | |
312 | * old parent. If this dentry persists later when a lookup | |
313 | * is performed at its new name the dentry will be readded | |
314 | * to the dcache hashes. | |
315 | */ | |
316 | mutex_unlock(&sysfs_mutex); | |
317 | ||
318 | /* If we have submounts we must allow the vfs caches | |
319 | * to lie about the state of the filesystem to prevent | |
320 | * leaks and other nasty things. | |
321 | */ | |
322 | if (check_submounts_and_drop(dentry) != 0) | |
323 | goto out_valid; | |
324 | ||
325 | return 0; | |
326 | } | |
327 | ||
328 | static void sysfs_dentry_release(struct dentry *dentry) | |
329 | { | |
330 | kernfs_put(dentry->d_fsdata); | |
331 | } | |
332 | ||
333 | const struct dentry_operations sysfs_dentry_ops = { | |
334 | .d_revalidate = sysfs_dentry_revalidate, | |
335 | .d_delete = sysfs_dentry_delete, | |
336 | .d_release = sysfs_dentry_release, | |
337 | }; | |
338 | ||
324a56e1 TH |
339 | struct kernfs_node *sysfs_new_dirent(struct kernfs_root *root, |
340 | const char *name, umode_t mode, int type) | |
fd7b9f7b TH |
341 | { |
342 | char *dup_name = NULL; | |
324a56e1 | 343 | struct kernfs_node *kn; |
bc755553 | 344 | int ret; |
fd7b9f7b TH |
345 | |
346 | if (type & SYSFS_COPY_NAME) { | |
347 | name = dup_name = kstrdup(name, GFP_KERNEL); | |
348 | if (!name) | |
349 | return NULL; | |
350 | } | |
351 | ||
324a56e1 TH |
352 | kn = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); |
353 | if (!kn) | |
fd7b9f7b TH |
354 | goto err_out1; |
355 | ||
bc755553 TH |
356 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
357 | if (ret < 0) | |
fd7b9f7b | 358 | goto err_out2; |
324a56e1 | 359 | kn->s_ino = ret; |
fd7b9f7b | 360 | |
324a56e1 TH |
361 | atomic_set(&kn->s_count, 1); |
362 | atomic_set(&kn->s_active, 0); | |
fd7b9f7b | 363 | |
324a56e1 TH |
364 | kn->s_name = name; |
365 | kn->s_mode = mode; | |
366 | kn->s_flags = type | SYSFS_FLAG_REMOVED; | |
fd7b9f7b | 367 | |
324a56e1 | 368 | return kn; |
fd7b9f7b TH |
369 | |
370 | err_out2: | |
324a56e1 | 371 | kmem_cache_free(sysfs_dir_cachep, kn); |
fd7b9f7b TH |
372 | err_out1: |
373 | kfree(dup_name); | |
374 | return NULL; | |
375 | } | |
376 | ||
377 | /** | |
324a56e1 | 378 | * sysfs_addrm_start - prepare for kernfs_node add/remove |
fd7b9f7b TH |
379 | * @acxt: pointer to sysfs_addrm_cxt to be used |
380 | * | |
381 | * This function is called when the caller is about to add or remove | |
324a56e1 TH |
382 | * kernfs_node. This function acquires sysfs_mutex. @acxt is used to |
383 | * keep and pass context to other addrm functions. | |
fd7b9f7b TH |
384 | * |
385 | * LOCKING: | |
386 | * Kernel thread context (may sleep). sysfs_mutex is locked on | |
387 | * return. | |
388 | */ | |
389 | void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt) | |
390 | __acquires(sysfs_mutex) | |
391 | { | |
392 | memset(acxt, 0, sizeof(*acxt)); | |
393 | ||
394 | mutex_lock(&sysfs_mutex); | |
395 | } | |
396 | ||
397 | /** | |
324a56e1 | 398 | * sysfs_add_one - add kernfs_node to parent without warning |
fd7b9f7b | 399 | * @acxt: addrm context to use |
324a56e1 TH |
400 | * @kn: kernfs_node to be added |
401 | * @parent: the parent kernfs_node to add @kn to | |
fd7b9f7b | 402 | * |
324a56e1 TH |
403 | * Get @parent and set @kn->s_parent to it and increment nlink of |
404 | * the parent inode if @kn is a directory and link into the children | |
fd7b9f7b TH |
405 | * list of the parent. |
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(). | |
413 | * | |
414 | * RETURNS: | |
415 | * 0 on success, -EEXIST if entry with the given name already | |
416 | * exists. | |
417 | */ | |
324a56e1 TH |
418 | int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct kernfs_node *kn, |
419 | struct kernfs_node *parent) | |
fd7b9f7b | 420 | { |
324a56e1 | 421 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
422 | struct sysfs_inode_attrs *ps_iattr; |
423 | int ret; | |
424 | ||
324a56e1 | 425 | if (has_ns != (bool)kn->s_ns) { |
fd7b9f7b TH |
426 | WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", |
427 | has_ns ? "required" : "invalid", | |
324a56e1 | 428 | parent->s_name, kn->s_name); |
fd7b9f7b TH |
429 | return -EINVAL; |
430 | } | |
431 | ||
324a56e1 | 432 | if (sysfs_type(parent) != SYSFS_DIR) |
fd7b9f7b TH |
433 | return -EINVAL; |
434 | ||
324a56e1 TH |
435 | kn->s_hash = sysfs_name_hash(kn->s_name, kn->s_ns); |
436 | kn->s_parent = parent; | |
437 | kernfs_get(parent); | |
fd7b9f7b | 438 | |
324a56e1 | 439 | ret = sysfs_link_sibling(kn); |
fd7b9f7b TH |
440 | if (ret) |
441 | return ret; | |
442 | ||
443 | /* Update timestamps on the parent */ | |
324a56e1 | 444 | ps_iattr = parent->s_iattr; |
fd7b9f7b TH |
445 | if (ps_iattr) { |
446 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
447 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
448 | } | |
449 | ||
450 | /* Mark the entry added into directory tree */ | |
324a56e1 | 451 | kn->s_flags &= ~SYSFS_FLAG_REMOVED; |
fd7b9f7b TH |
452 | |
453 | return 0; | |
454 | } | |
455 | ||
456 | /** | |
324a56e1 | 457 | * sysfs_remove_one - remove kernfs_node from parent |
fd7b9f7b | 458 | * @acxt: addrm context to use |
324a56e1 | 459 | * @kn: kernfs_node to be removed |
fd7b9f7b | 460 | * |
324a56e1 TH |
461 | * Mark @kn removed and drop nlink of parent inode if @kn is a |
462 | * directory. @kn is unlinked from the children list. | |
fd7b9f7b TH |
463 | * |
464 | * This function should be called between calls to | |
465 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
466 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
467 | * | |
468 | * LOCKING: | |
469 | * Determined by sysfs_addrm_start(). | |
470 | */ | |
471 | static void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, | |
324a56e1 | 472 | struct kernfs_node *kn) |
fd7b9f7b TH |
473 | { |
474 | struct sysfs_inode_attrs *ps_iattr; | |
475 | ||
476 | /* | |
477 | * Removal can be called multiple times on the same node. Only the | |
478 | * first invocation is effective and puts the base ref. | |
479 | */ | |
324a56e1 | 480 | if (kn->s_flags & SYSFS_FLAG_REMOVED) |
fd7b9f7b TH |
481 | return; |
482 | ||
324a56e1 TH |
483 | if (kn->s_parent) { |
484 | sysfs_unlink_sibling(kn); | |
fd7b9f7b | 485 | |
ba7443bc | 486 | /* Update timestamps on the parent */ |
324a56e1 | 487 | ps_iattr = kn->s_parent->s_iattr; |
ba7443bc TH |
488 | if (ps_iattr) { |
489 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
490 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
491 | } | |
fd7b9f7b TH |
492 | } |
493 | ||
324a56e1 TH |
494 | kn->s_flags |= SYSFS_FLAG_REMOVED; |
495 | kn->u.removed_list = acxt->removed; | |
496 | acxt->removed = kn; | |
fd7b9f7b TH |
497 | } |
498 | ||
499 | /** | |
324a56e1 | 500 | * sysfs_addrm_finish - finish up kernfs_node add/remove |
fd7b9f7b TH |
501 | * @acxt: addrm context to finish up |
502 | * | |
324a56e1 TH |
503 | * Finish up kernfs_node add/remove. Resources acquired by |
504 | * sysfs_addrm_start() are released and removed kernfs_nodes are | |
fd7b9f7b TH |
505 | * cleaned up. |
506 | * | |
507 | * LOCKING: | |
508 | * sysfs_mutex is released. | |
509 | */ | |
510 | void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) | |
511 | __releases(sysfs_mutex) | |
512 | { | |
513 | /* release resources acquired by sysfs_addrm_start() */ | |
514 | mutex_unlock(&sysfs_mutex); | |
515 | ||
324a56e1 | 516 | /* kill removed kernfs_nodes */ |
fd7b9f7b | 517 | while (acxt->removed) { |
324a56e1 | 518 | struct kernfs_node *kn = acxt->removed; |
fd7b9f7b | 519 | |
324a56e1 | 520 | acxt->removed = kn->u.removed_list; |
fd7b9f7b | 521 | |
324a56e1 TH |
522 | sysfs_deactivate(kn); |
523 | sysfs_unmap_bin_file(kn); | |
524 | kernfs_put(kn); | |
fd7b9f7b TH |
525 | } |
526 | } | |
527 | ||
528 | /** | |
324a56e1 TH |
529 | * kernfs_find_ns - find kernfs_node with the given name |
530 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
531 | * @name: name to look for |
532 | * @ns: the namespace tag to use | |
533 | * | |
324a56e1 TH |
534 | * Look for kernfs_node with name @name under @parent. Returns pointer to |
535 | * the found kernfs_node on success, %NULL on failure. | |
fd7b9f7b | 536 | */ |
324a56e1 TH |
537 | static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, |
538 | const unsigned char *name, | |
539 | const void *ns) | |
fd7b9f7b TH |
540 | { |
541 | struct rb_node *node = parent->s_dir.children.rb_node; | |
ac9bba03 | 542 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
543 | unsigned int hash; |
544 | ||
545 | lockdep_assert_held(&sysfs_mutex); | |
546 | ||
547 | if (has_ns != (bool)ns) { | |
548 | WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", | |
549 | has_ns ? "required" : "invalid", | |
550 | parent->s_name, name); | |
551 | return NULL; | |
552 | } | |
553 | ||
554 | hash = sysfs_name_hash(name, ns); | |
555 | while (node) { | |
324a56e1 | 556 | struct kernfs_node *kn; |
fd7b9f7b TH |
557 | int result; |
558 | ||
324a56e1 TH |
559 | kn = rb_to_kn(node); |
560 | result = sysfs_name_compare(hash, name, ns, kn); | |
fd7b9f7b TH |
561 | if (result < 0) |
562 | node = node->rb_left; | |
563 | else if (result > 0) | |
564 | node = node->rb_right; | |
565 | else | |
324a56e1 | 566 | return kn; |
fd7b9f7b TH |
567 | } |
568 | return NULL; | |
569 | } | |
570 | ||
571 | /** | |
324a56e1 TH |
572 | * kernfs_find_and_get_ns - find and get kernfs_node with the given name |
573 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
574 | * @name: name to look for |
575 | * @ns: the namespace tag to use | |
576 | * | |
324a56e1 | 577 | * Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b | 578 | * if found. This function may sleep and returns pointer to the found |
324a56e1 | 579 | * kernfs_node on success, %NULL on failure. |
fd7b9f7b | 580 | */ |
324a56e1 TH |
581 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
582 | const char *name, const void *ns) | |
fd7b9f7b | 583 | { |
324a56e1 | 584 | struct kernfs_node *kn; |
fd7b9f7b TH |
585 | |
586 | mutex_lock(&sysfs_mutex); | |
324a56e1 TH |
587 | kn = kernfs_find_ns(parent, name, ns); |
588 | kernfs_get(kn); | |
fd7b9f7b TH |
589 | mutex_unlock(&sysfs_mutex); |
590 | ||
324a56e1 | 591 | return kn; |
fd7b9f7b TH |
592 | } |
593 | EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); | |
594 | ||
ba7443bc TH |
595 | /** |
596 | * kernfs_create_root - create a new kernfs hierarchy | |
597 | * @priv: opaque data associated with the new directory | |
598 | * | |
599 | * Returns the root of the new hierarchy on success, ERR_PTR() value on | |
600 | * failure. | |
601 | */ | |
602 | struct kernfs_root *kernfs_create_root(void *priv) | |
603 | { | |
604 | struct kernfs_root *root; | |
324a56e1 | 605 | struct kernfs_node *kn; |
ba7443bc TH |
606 | |
607 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
608 | if (!root) | |
609 | return ERR_PTR(-ENOMEM); | |
610 | ||
bc755553 TH |
611 | ida_init(&root->ino_ida); |
612 | ||
324a56e1 TH |
613 | kn = sysfs_new_dirent(root, "", S_IFDIR | S_IRUGO | S_IXUGO, SYSFS_DIR); |
614 | if (!kn) { | |
bc755553 | 615 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
616 | kfree(root); |
617 | return ERR_PTR(-ENOMEM); | |
618 | } | |
619 | ||
324a56e1 TH |
620 | kn->s_flags &= ~SYSFS_FLAG_REMOVED; |
621 | kn->priv = priv; | |
622 | kn->s_dir.root = root; | |
ba7443bc | 623 | |
324a56e1 | 624 | root->kn = kn; |
ba7443bc TH |
625 | |
626 | return root; | |
627 | } | |
628 | ||
629 | /** | |
630 | * kernfs_destroy_root - destroy a kernfs hierarchy | |
631 | * @root: root of the hierarchy to destroy | |
632 | * | |
633 | * Destroy the hierarchy anchored at @root by removing all existing | |
634 | * directories and destroying @root. | |
635 | */ | |
636 | void kernfs_destroy_root(struct kernfs_root *root) | |
637 | { | |
324a56e1 | 638 | kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc TH |
639 | } |
640 | ||
fd7b9f7b TH |
641 | /** |
642 | * kernfs_create_dir_ns - create a directory | |
643 | * @parent: parent in which to create a new directory | |
644 | * @name: name of the new directory | |
645 | * @priv: opaque data associated with the new directory | |
646 | * @ns: optional namespace tag of the directory | |
647 | * | |
648 | * Returns the created node on success, ERR_PTR() value on failure. | |
649 | */ | |
324a56e1 TH |
650 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
651 | const char *name, void *priv, | |
652 | const void *ns) | |
fd7b9f7b TH |
653 | { |
654 | umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; | |
655 | struct sysfs_addrm_cxt acxt; | |
324a56e1 | 656 | struct kernfs_node *kn; |
fd7b9f7b TH |
657 | int rc; |
658 | ||
659 | /* allocate */ | |
324a56e1 TH |
660 | kn = sysfs_new_dirent(kernfs_root(parent), name, mode, SYSFS_DIR); |
661 | if (!kn) | |
fd7b9f7b TH |
662 | return ERR_PTR(-ENOMEM); |
663 | ||
324a56e1 TH |
664 | kn->s_dir.root = parent->s_dir.root; |
665 | kn->s_ns = ns; | |
666 | kn->priv = priv; | |
fd7b9f7b TH |
667 | |
668 | /* link in */ | |
669 | sysfs_addrm_start(&acxt); | |
324a56e1 | 670 | rc = sysfs_add_one(&acxt, kn, parent); |
fd7b9f7b TH |
671 | sysfs_addrm_finish(&acxt); |
672 | ||
673 | if (!rc) | |
324a56e1 | 674 | return kn; |
fd7b9f7b | 675 | |
324a56e1 | 676 | kernfs_put(kn); |
fd7b9f7b TH |
677 | return ERR_PTR(rc); |
678 | } | |
679 | ||
680 | static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry, | |
681 | unsigned int flags) | |
682 | { | |
683 | struct dentry *ret = NULL; | |
324a56e1 TH |
684 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
685 | struct kernfs_node *kn; | |
fd7b9f7b TH |
686 | struct inode *inode; |
687 | const void *ns = NULL; | |
688 | ||
689 | mutex_lock(&sysfs_mutex); | |
690 | ||
324a56e1 | 691 | if (kernfs_ns_enabled(parent)) |
fd7b9f7b TH |
692 | ns = sysfs_info(dir->i_sb)->ns; |
693 | ||
324a56e1 | 694 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
695 | |
696 | /* no such entry */ | |
324a56e1 | 697 | if (!kn) { |
fd7b9f7b TH |
698 | ret = ERR_PTR(-ENOENT); |
699 | goto out_unlock; | |
700 | } | |
324a56e1 TH |
701 | kernfs_get(kn); |
702 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
703 | |
704 | /* attach dentry and inode */ | |
324a56e1 | 705 | inode = sysfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
706 | if (!inode) { |
707 | ret = ERR_PTR(-ENOMEM); | |
708 | goto out_unlock; | |
709 | } | |
710 | ||
711 | /* instantiate and hash dentry */ | |
712 | ret = d_materialise_unique(dentry, inode); | |
713 | out_unlock: | |
714 | mutex_unlock(&sysfs_mutex); | |
715 | return ret; | |
716 | } | |
717 | ||
718 | const struct inode_operations sysfs_dir_inode_operations = { | |
719 | .lookup = sysfs_lookup, | |
720 | .permission = sysfs_permission, | |
721 | .setattr = sysfs_setattr, | |
722 | .getattr = sysfs_getattr, | |
723 | .setxattr = sysfs_setxattr, | |
2322392b TH |
724 | .removexattr = sysfs_removexattr, |
725 | .getxattr = sysfs_getxattr, | |
726 | .listxattr = sysfs_listxattr, | |
fd7b9f7b TH |
727 | }; |
728 | ||
324a56e1 | 729 | static struct kernfs_node *sysfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 730 | { |
324a56e1 | 731 | struct kernfs_node *last; |
fd7b9f7b TH |
732 | |
733 | while (true) { | |
734 | struct rb_node *rbn; | |
735 | ||
736 | last = pos; | |
737 | ||
738 | if (sysfs_type(pos) != SYSFS_DIR) | |
739 | break; | |
740 | ||
741 | rbn = rb_first(&pos->s_dir.children); | |
742 | if (!rbn) | |
743 | break; | |
744 | ||
324a56e1 | 745 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
746 | } |
747 | ||
748 | return last; | |
749 | } | |
750 | ||
751 | /** | |
752 | * sysfs_next_descendant_post - find the next descendant for post-order walk | |
753 | * @pos: the current position (%NULL to initiate traversal) | |
324a56e1 | 754 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
755 | * |
756 | * Find the next descendant to visit for post-order traversal of @root's | |
757 | * descendants. @root is included in the iteration and the last node to be | |
758 | * visited. | |
759 | */ | |
324a56e1 TH |
760 | static struct kernfs_node *sysfs_next_descendant_post(struct kernfs_node *pos, |
761 | struct kernfs_node *root) | |
fd7b9f7b TH |
762 | { |
763 | struct rb_node *rbn; | |
764 | ||
765 | lockdep_assert_held(&sysfs_mutex); | |
766 | ||
767 | /* if first iteration, visit leftmost descendant which may be root */ | |
768 | if (!pos) | |
769 | return sysfs_leftmost_descendant(root); | |
770 | ||
771 | /* if we visited @root, we're done */ | |
772 | if (pos == root) | |
773 | return NULL; | |
774 | ||
775 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
776 | rbn = rb_next(&pos->s_rb); | |
777 | if (rbn) | |
324a56e1 | 778 | return sysfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
779 | |
780 | /* no sibling left, visit parent */ | |
781 | return pos->s_parent; | |
782 | } | |
783 | ||
784 | static void __kernfs_remove(struct sysfs_addrm_cxt *acxt, | |
324a56e1 | 785 | struct kernfs_node *kn) |
fd7b9f7b | 786 | { |
324a56e1 | 787 | struct kernfs_node *pos, *next; |
fd7b9f7b | 788 | |
324a56e1 | 789 | if (!kn) |
fd7b9f7b TH |
790 | return; |
791 | ||
324a56e1 | 792 | pr_debug("sysfs %s: removing\n", kn->s_name); |
fd7b9f7b TH |
793 | |
794 | next = NULL; | |
795 | do { | |
796 | pos = next; | |
324a56e1 | 797 | next = sysfs_next_descendant_post(pos, kn); |
fd7b9f7b TH |
798 | if (pos) |
799 | sysfs_remove_one(acxt, pos); | |
800 | } while (next); | |
801 | } | |
802 | ||
803 | /** | |
324a56e1 TH |
804 | * kernfs_remove - remove a kernfs_node recursively |
805 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 806 | * |
324a56e1 | 807 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 808 | */ |
324a56e1 | 809 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b TH |
810 | { |
811 | struct sysfs_addrm_cxt acxt; | |
812 | ||
813 | sysfs_addrm_start(&acxt); | |
324a56e1 | 814 | __kernfs_remove(&acxt, kn); |
fd7b9f7b TH |
815 | sysfs_addrm_finish(&acxt); |
816 | } | |
817 | ||
818 | /** | |
324a56e1 TH |
819 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
820 | * @parent: parent of the target | |
821 | * @name: name of the kernfs_node to remove | |
822 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 823 | * |
324a56e1 TH |
824 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
825 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 826 | */ |
324a56e1 | 827 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
828 | const void *ns) |
829 | { | |
830 | struct sysfs_addrm_cxt acxt; | |
324a56e1 | 831 | struct kernfs_node *kn; |
fd7b9f7b | 832 | |
324a56e1 | 833 | if (!parent) { |
fd7b9f7b TH |
834 | WARN(1, KERN_WARNING "sysfs: can not remove '%s', no directory\n", |
835 | name); | |
836 | return -ENOENT; | |
837 | } | |
838 | ||
839 | sysfs_addrm_start(&acxt); | |
840 | ||
324a56e1 TH |
841 | kn = kernfs_find_ns(parent, name, ns); |
842 | if (kn) | |
843 | __kernfs_remove(&acxt, kn); | |
fd7b9f7b TH |
844 | |
845 | sysfs_addrm_finish(&acxt); | |
846 | ||
324a56e1 | 847 | if (kn) |
fd7b9f7b TH |
848 | return 0; |
849 | else | |
850 | return -ENOENT; | |
851 | } | |
852 | ||
853 | /** | |
854 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 855 | * @kn: target node |
fd7b9f7b TH |
856 | * @new_parent: new parent to put @sd under |
857 | * @new_name: new name | |
858 | * @new_ns: new namespace tag | |
859 | */ | |
324a56e1 | 860 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
861 | const char *new_name, const void *new_ns) |
862 | { | |
863 | int error; | |
864 | ||
865 | mutex_lock(&sysfs_mutex); | |
866 | ||
867 | error = 0; | |
324a56e1 TH |
868 | if ((kn->s_parent == new_parent) && (kn->s_ns == new_ns) && |
869 | (strcmp(kn->s_name, new_name) == 0)) | |
fd7b9f7b TH |
870 | goto out; /* nothing to rename */ |
871 | ||
872 | error = -EEXIST; | |
873 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
874 | goto out; | |
875 | ||
324a56e1 TH |
876 | /* rename kernfs_node */ |
877 | if (strcmp(kn->s_name, new_name) != 0) { | |
fd7b9f7b TH |
878 | error = -ENOMEM; |
879 | new_name = kstrdup(new_name, GFP_KERNEL); | |
880 | if (!new_name) | |
881 | goto out; | |
882 | ||
324a56e1 TH |
883 | kfree(kn->s_name); |
884 | kn->s_name = new_name; | |
fd7b9f7b TH |
885 | } |
886 | ||
887 | /* | |
888 | * Move to the appropriate place in the appropriate directories rbtree. | |
889 | */ | |
324a56e1 | 890 | sysfs_unlink_sibling(kn); |
fd7b9f7b | 891 | kernfs_get(new_parent); |
324a56e1 TH |
892 | kernfs_put(kn->s_parent); |
893 | kn->s_ns = new_ns; | |
894 | kn->s_hash = sysfs_name_hash(kn->s_name, kn->s_ns); | |
895 | kn->s_parent = new_parent; | |
896 | sysfs_link_sibling(kn); | |
fd7b9f7b TH |
897 | |
898 | error = 0; | |
899 | out: | |
900 | mutex_unlock(&sysfs_mutex); | |
901 | return error; | |
902 | } | |
903 | ||
fd7b9f7b | 904 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 905 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 906 | { |
324a56e1 | 907 | return (kn->s_mode >> 12) & 15; |
fd7b9f7b TH |
908 | } |
909 | ||
910 | static int sysfs_dir_release(struct inode *inode, struct file *filp) | |
911 | { | |
912 | kernfs_put(filp->private_data); | |
913 | return 0; | |
914 | } | |
915 | ||
324a56e1 TH |
916 | static struct kernfs_node *sysfs_dir_pos(const void *ns, |
917 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) | |
fd7b9f7b TH |
918 | { |
919 | if (pos) { | |
920 | int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) && | |
324a56e1 | 921 | pos->s_parent == parent && |
fd7b9f7b TH |
922 | hash == pos->s_hash; |
923 | kernfs_put(pos); | |
924 | if (!valid) | |
925 | pos = NULL; | |
926 | } | |
927 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
324a56e1 | 928 | struct rb_node *node = parent->s_dir.children.rb_node; |
fd7b9f7b | 929 | while (node) { |
324a56e1 | 930 | pos = rb_to_kn(node); |
fd7b9f7b TH |
931 | |
932 | if (hash < pos->s_hash) | |
933 | node = node->rb_left; | |
934 | else if (hash > pos->s_hash) | |
935 | node = node->rb_right; | |
936 | else | |
937 | break; | |
938 | } | |
939 | } | |
940 | /* Skip over entries in the wrong namespace */ | |
941 | while (pos && pos->s_ns != ns) { | |
942 | struct rb_node *node = rb_next(&pos->s_rb); | |
943 | if (!node) | |
944 | pos = NULL; | |
945 | else | |
324a56e1 | 946 | pos = rb_to_kn(node); |
fd7b9f7b TH |
947 | } |
948 | return pos; | |
949 | } | |
950 | ||
324a56e1 TH |
951 | static struct kernfs_node *sysfs_dir_next_pos(const void *ns, |
952 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) | |
fd7b9f7b | 953 | { |
324a56e1 | 954 | pos = sysfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
955 | if (pos) |
956 | do { | |
957 | struct rb_node *node = rb_next(&pos->s_rb); | |
958 | if (!node) | |
959 | pos = NULL; | |
960 | else | |
324a56e1 | 961 | pos = rb_to_kn(node); |
fd7b9f7b TH |
962 | } while (pos && pos->s_ns != ns); |
963 | return pos; | |
964 | } | |
965 | ||
966 | static int sysfs_readdir(struct file *file, struct dir_context *ctx) | |
967 | { | |
968 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
969 | struct kernfs_node *parent = dentry->d_fsdata; |
970 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
971 | const void *ns = NULL; |
972 | ||
973 | if (!dir_emit_dots(file, ctx)) | |
974 | return 0; | |
975 | mutex_lock(&sysfs_mutex); | |
976 | ||
324a56e1 | 977 | if (kernfs_ns_enabled(parent)) |
fd7b9f7b TH |
978 | ns = sysfs_info(dentry->d_sb)->ns; |
979 | ||
324a56e1 | 980 | for (pos = sysfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 981 | pos; |
324a56e1 | 982 | pos = sysfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
fd7b9f7b TH |
983 | const char *name = pos->s_name; |
984 | unsigned int type = dt_type(pos); | |
985 | int len = strlen(name); | |
986 | ino_t ino = pos->s_ino; | |
987 | ||
988 | ctx->pos = pos->s_hash; | |
989 | file->private_data = pos; | |
990 | kernfs_get(pos); | |
991 | ||
992 | mutex_unlock(&sysfs_mutex); | |
993 | if (!dir_emit(ctx, name, len, ino, type)) | |
994 | return 0; | |
995 | mutex_lock(&sysfs_mutex); | |
996 | } | |
997 | mutex_unlock(&sysfs_mutex); | |
998 | file->private_data = NULL; | |
999 | ctx->pos = INT_MAX; | |
1000 | return 0; | |
1001 | } | |
1002 | ||
1003 | static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence) | |
1004 | { | |
1005 | struct inode *inode = file_inode(file); | |
1006 | loff_t ret; | |
1007 | ||
1008 | mutex_lock(&inode->i_mutex); | |
1009 | ret = generic_file_llseek(file, offset, whence); | |
1010 | mutex_unlock(&inode->i_mutex); | |
1011 | ||
1012 | return ret; | |
1013 | } | |
1014 | ||
1015 | const struct file_operations sysfs_dir_operations = { | |
1016 | .read = generic_read_dir, | |
1017 | .iterate = sysfs_readdir, | |
1018 | .release = sysfs_dir_release, | |
1019 | .llseek = sysfs_dir_llseek, | |
1020 | }; |