Commit | Line | Data |
---|---|---|
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 | 10 | |
ea1c472d | 11 | #include <linux/sched.h> |
fd7b9f7b TH |
12 | #include <linux/fs.h> |
13 | #include <linux/namei.h> | |
14 | #include <linux/idr.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/security.h> | |
17 | #include <linux/hash.h> | |
18 | ||
19 | #include "kernfs-internal.h" | |
20 | ||
a797bfc3 | 21 | DEFINE_MUTEX(kernfs_mutex); |
fd7b9f7b | 22 | |
adc5e8b5 | 23 | #define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb) |
fd7b9f7b | 24 | |
a69d001c TH |
25 | static bool kernfs_lockdep(struct kernfs_node *kn) |
26 | { | |
27 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
28 | return kn->flags & KERNFS_LOCKDEP; | |
29 | #else | |
30 | return false; | |
31 | #endif | |
32 | } | |
33 | ||
fd7b9f7b | 34 | /** |
c637b8ac | 35 | * kernfs_name_hash |
fd7b9f7b TH |
36 | * @name: Null terminated string to hash |
37 | * @ns: Namespace tag to hash | |
38 | * | |
39 | * Returns 31 bit hash of ns + name (so it fits in an off_t ) | |
40 | */ | |
c637b8ac | 41 | static unsigned int kernfs_name_hash(const char *name, const void *ns) |
fd7b9f7b TH |
42 | { |
43 | unsigned long hash = init_name_hash(); | |
44 | unsigned int len = strlen(name); | |
45 | while (len--) | |
46 | hash = partial_name_hash(*name++, hash); | |
47 | hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31)); | |
48 | hash &= 0x7fffffffU; | |
49 | /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ | |
50 | if (hash < 1) | |
51 | hash += 2; | |
52 | if (hash >= INT_MAX) | |
53 | hash = INT_MAX - 1; | |
54 | return hash; | |
55 | } | |
56 | ||
c637b8ac TH |
57 | static int kernfs_name_compare(unsigned int hash, const char *name, |
58 | const void *ns, const struct kernfs_node *kn) | |
fd7b9f7b | 59 | { |
adc5e8b5 TH |
60 | if (hash != kn->hash) |
61 | return hash - kn->hash; | |
62 | if (ns != kn->ns) | |
63 | return ns - kn->ns; | |
64 | return strcmp(name, kn->name); | |
fd7b9f7b TH |
65 | } |
66 | ||
c637b8ac TH |
67 | static int kernfs_sd_compare(const struct kernfs_node *left, |
68 | const struct kernfs_node *right) | |
fd7b9f7b | 69 | { |
c637b8ac | 70 | return kernfs_name_compare(left->hash, left->name, left->ns, right); |
fd7b9f7b TH |
71 | } |
72 | ||
73 | /** | |
c637b8ac | 74 | * kernfs_link_sibling - link kernfs_node into sibling rbtree |
324a56e1 | 75 | * @kn: kernfs_node of interest |
fd7b9f7b | 76 | * |
324a56e1 | 77 | * Link @kn into its sibling rbtree which starts from |
adc5e8b5 | 78 | * @kn->parent->dir.children. |
fd7b9f7b TH |
79 | * |
80 | * Locking: | |
a797bfc3 | 81 | * mutex_lock(kernfs_mutex) |
fd7b9f7b TH |
82 | * |
83 | * RETURNS: | |
84 | * 0 on susccess -EEXIST on failure. | |
85 | */ | |
c637b8ac | 86 | static int kernfs_link_sibling(struct kernfs_node *kn) |
fd7b9f7b | 87 | { |
adc5e8b5 | 88 | struct rb_node **node = &kn->parent->dir.children.rb_node; |
fd7b9f7b TH |
89 | struct rb_node *parent = NULL; |
90 | ||
df23fc39 | 91 | if (kernfs_type(kn) == KERNFS_DIR) |
adc5e8b5 | 92 | kn->parent->dir.subdirs++; |
fd7b9f7b TH |
93 | |
94 | while (*node) { | |
324a56e1 | 95 | struct kernfs_node *pos; |
fd7b9f7b TH |
96 | int result; |
97 | ||
324a56e1 | 98 | pos = rb_to_kn(*node); |
fd7b9f7b | 99 | parent = *node; |
c637b8ac | 100 | result = kernfs_sd_compare(kn, pos); |
fd7b9f7b | 101 | if (result < 0) |
adc5e8b5 | 102 | node = &pos->rb.rb_left; |
fd7b9f7b | 103 | else if (result > 0) |
adc5e8b5 | 104 | node = &pos->rb.rb_right; |
fd7b9f7b TH |
105 | else |
106 | return -EEXIST; | |
107 | } | |
108 | /* add new node and rebalance the tree */ | |
adc5e8b5 TH |
109 | rb_link_node(&kn->rb, parent, node); |
110 | rb_insert_color(&kn->rb, &kn->parent->dir.children); | |
fd7b9f7b TH |
111 | return 0; |
112 | } | |
113 | ||
114 | /** | |
c637b8ac | 115 | * kernfs_unlink_sibling - unlink kernfs_node from sibling rbtree |
324a56e1 | 116 | * @kn: kernfs_node of interest |
fd7b9f7b | 117 | * |
324a56e1 | 118 | * Unlink @kn from its sibling rbtree which starts from |
adc5e8b5 | 119 | * kn->parent->dir.children. |
fd7b9f7b TH |
120 | * |
121 | * Locking: | |
a797bfc3 | 122 | * mutex_lock(kernfs_mutex) |
fd7b9f7b | 123 | */ |
55f6e30d | 124 | static void kernfs_unlink_sibling(struct kernfs_node *kn) |
fd7b9f7b | 125 | { |
df23fc39 | 126 | if (kernfs_type(kn) == KERNFS_DIR) |
adc5e8b5 | 127 | kn->parent->dir.subdirs--; |
fd7b9f7b | 128 | |
adc5e8b5 | 129 | rb_erase(&kn->rb, &kn->parent->dir.children); |
ae34372e | 130 | RB_CLEAR_NODE(&kn->rb); |
fd7b9f7b TH |
131 | } |
132 | ||
133 | /** | |
c637b8ac | 134 | * kernfs_get_active - get an active reference to kernfs_node |
324a56e1 | 135 | * @kn: kernfs_node to get an active reference to |
fd7b9f7b | 136 | * |
324a56e1 | 137 | * Get an active reference of @kn. This function is noop if @kn |
fd7b9f7b TH |
138 | * is NULL. |
139 | * | |
140 | * RETURNS: | |
324a56e1 | 141 | * Pointer to @kn on success, NULL on failure. |
fd7b9f7b | 142 | */ |
c637b8ac | 143 | struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) |
fd7b9f7b | 144 | { |
324a56e1 | 145 | if (unlikely(!kn)) |
fd7b9f7b TH |
146 | return NULL; |
147 | ||
f4b3e631 GKH |
148 | if (!atomic_inc_unless_negative(&kn->active)) |
149 | return NULL; | |
895a068a TH |
150 | |
151 | if (kernfs_lockdep(kn)) | |
f4b3e631 GKH |
152 | rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_); |
153 | return kn; | |
fd7b9f7b TH |
154 | } |
155 | ||
156 | /** | |
c637b8ac | 157 | * kernfs_put_active - put an active reference to kernfs_node |
324a56e1 | 158 | * @kn: kernfs_node to put an active reference to |
fd7b9f7b | 159 | * |
324a56e1 | 160 | * Put an active reference to @kn. This function is noop if @kn |
fd7b9f7b TH |
161 | * is NULL. |
162 | */ | |
c637b8ac | 163 | void kernfs_put_active(struct kernfs_node *kn) |
fd7b9f7b | 164 | { |
ea1c472d | 165 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b TH |
166 | int v; |
167 | ||
324a56e1 | 168 | if (unlikely(!kn)) |
fd7b9f7b TH |
169 | return; |
170 | ||
a69d001c | 171 | if (kernfs_lockdep(kn)) |
324a56e1 | 172 | rwsem_release(&kn->dep_map, 1, _RET_IP_); |
adc5e8b5 | 173 | v = atomic_dec_return(&kn->active); |
df23fc39 | 174 | if (likely(v != KN_DEACTIVATED_BIAS)) |
fd7b9f7b TH |
175 | return; |
176 | ||
ea1c472d | 177 | wake_up_all(&root->deactivate_waitq); |
fd7b9f7b TH |
178 | } |
179 | ||
180 | /** | |
ae34372e TH |
181 | * kernfs_drain - drain kernfs_node |
182 | * @kn: kernfs_node to drain | |
fd7b9f7b | 183 | * |
45a140e5 TH |
184 | * Drain existing usages of @kn. Mutiple removers may invoke this function |
185 | * concurrently on @kn and all will return after draining is complete. | |
186 | * Returns %true if drain is performed and kernfs_mutex was temporarily | |
187 | * released. %false if @kn was already drained and no operation was | |
188 | * necessary. | |
189 | * | |
190 | * The caller is responsible for ensuring @kn stays pinned while this | |
191 | * function is in progress even if it gets removed by someone else. | |
fd7b9f7b | 192 | */ |
45a140e5 TH |
193 | static bool kernfs_drain(struct kernfs_node *kn) |
194 | __releases(&kernfs_mutex) __acquires(&kernfs_mutex) | |
fd7b9f7b | 195 | { |
ea1c472d | 196 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b | 197 | |
45a140e5 | 198 | lockdep_assert_held(&kernfs_mutex); |
ae34372e | 199 | WARN_ON_ONCE(atomic_read(&kn->active) >= 0); |
ea1c472d | 200 | |
45a140e5 TH |
201 | /* |
202 | * We want to go through the active ref lockdep annotation at least | |
203 | * once for all node removals, but the lockdep annotation can't be | |
204 | * nested inside kernfs_mutex and deactivation can't make forward | |
205 | * progress if we keep dropping the mutex. Use JUST_ACTIVATED to | |
206 | * force the slow path once for each deactivation if lockdep is | |
207 | * enabled. | |
208 | */ | |
209 | if ((!kernfs_lockdep(kn) || !(kn->flags & KERNFS_JUST_DEACTIVATED)) && | |
210 | atomic_read(&kn->active) == KN_DEACTIVATED_BIAS) | |
211 | return false; | |
212 | ||
213 | kn->flags &= ~KERNFS_JUST_DEACTIVATED; | |
214 | mutex_unlock(&kernfs_mutex); | |
215 | ||
a69d001c TH |
216 | if (kernfs_lockdep(kn)) { |
217 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); | |
218 | if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS) | |
219 | lock_contended(&kn->dep_map, _RET_IP_); | |
220 | } | |
ea1c472d TH |
221 | |
222 | wait_event(root->deactivate_waitq, | |
223 | atomic_read(&kn->active) == KN_DEACTIVATED_BIAS); | |
fd7b9f7b | 224 | |
a69d001c TH |
225 | if (kernfs_lockdep(kn)) { |
226 | lock_acquired(&kn->dep_map, _RET_IP_); | |
227 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
228 | } | |
45a140e5 TH |
229 | |
230 | mutex_lock(&kernfs_mutex); | |
231 | return true; | |
fd7b9f7b TH |
232 | } |
233 | ||
fd7b9f7b | 234 | /** |
324a56e1 TH |
235 | * kernfs_get - get a reference count on a kernfs_node |
236 | * @kn: the target kernfs_node | |
fd7b9f7b | 237 | */ |
324a56e1 | 238 | void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b | 239 | { |
324a56e1 | 240 | if (kn) { |
adc5e8b5 TH |
241 | WARN_ON(!atomic_read(&kn->count)); |
242 | atomic_inc(&kn->count); | |
fd7b9f7b TH |
243 | } |
244 | } | |
245 | EXPORT_SYMBOL_GPL(kernfs_get); | |
246 | ||
247 | /** | |
324a56e1 TH |
248 | * kernfs_put - put a reference count on a kernfs_node |
249 | * @kn: the target kernfs_node | |
fd7b9f7b | 250 | * |
324a56e1 | 251 | * Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b | 252 | */ |
324a56e1 | 253 | void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b | 254 | { |
324a56e1 | 255 | struct kernfs_node *parent; |
ba7443bc | 256 | struct kernfs_root *root; |
fd7b9f7b | 257 | |
adc5e8b5 | 258 | if (!kn || !atomic_dec_and_test(&kn->count)) |
fd7b9f7b | 259 | return; |
324a56e1 | 260 | root = kernfs_root(kn); |
fd7b9f7b | 261 | repeat: |
ae34372e TH |
262 | /* |
263 | * Moving/renaming is always done while holding reference. | |
adc5e8b5 | 264 | * kn->parent won't change beneath us. |
fd7b9f7b | 265 | */ |
adc5e8b5 | 266 | parent = kn->parent; |
fd7b9f7b | 267 | |
ae34372e TH |
268 | WARN_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS, |
269 | "kernfs_put: %s/%s: released with incorrect active_ref %d\n", | |
270 | parent ? parent->name : "", kn->name, atomic_read(&kn->active)); | |
324a56e1 | 271 | |
df23fc39 | 272 | if (kernfs_type(kn) == KERNFS_LINK) |
adc5e8b5 | 273 | kernfs_put(kn->symlink.target_kn); |
2063d608 | 274 | if (!(kn->flags & KERNFS_STATIC_NAME)) |
adc5e8b5 TH |
275 | kfree(kn->name); |
276 | if (kn->iattr) { | |
277 | if (kn->iattr->ia_secdata) | |
278 | security_release_secctx(kn->iattr->ia_secdata, | |
279 | kn->iattr->ia_secdata_len); | |
280 | simple_xattrs_free(&kn->iattr->xattrs); | |
2322392b | 281 | } |
adc5e8b5 TH |
282 | kfree(kn->iattr); |
283 | ida_simple_remove(&root->ino_ida, kn->ino); | |
a797bfc3 | 284 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b | 285 | |
324a56e1 TH |
286 | kn = parent; |
287 | if (kn) { | |
adc5e8b5 | 288 | if (atomic_dec_and_test(&kn->count)) |
ba7443bc TH |
289 | goto repeat; |
290 | } else { | |
324a56e1 | 291 | /* just released the root kn, free @root too */ |
bc755553 | 292 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
293 | kfree(root); |
294 | } | |
fd7b9f7b TH |
295 | } |
296 | EXPORT_SYMBOL_GPL(kernfs_put); | |
297 | ||
c637b8ac | 298 | static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags) |
fd7b9f7b | 299 | { |
324a56e1 | 300 | struct kernfs_node *kn; |
fd7b9f7b TH |
301 | |
302 | if (flags & LOOKUP_RCU) | |
303 | return -ECHILD; | |
304 | ||
19bbb926 TH |
305 | /* Always perform fresh lookup for negatives */ |
306 | if (!dentry->d_inode) | |
307 | goto out_bad_unlocked; | |
308 | ||
324a56e1 | 309 | kn = dentry->d_fsdata; |
a797bfc3 | 310 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 311 | |
ae34372e TH |
312 | /* Force fresh lookup if removed */ |
313 | if (kn->parent && RB_EMPTY_NODE(&kn->rb)) | |
fd7b9f7b TH |
314 | goto out_bad; |
315 | ||
c637b8ac | 316 | /* The kernfs node has been moved? */ |
adc5e8b5 | 317 | if (dentry->d_parent->d_fsdata != kn->parent) |
fd7b9f7b TH |
318 | goto out_bad; |
319 | ||
c637b8ac | 320 | /* The kernfs node has been renamed */ |
adc5e8b5 | 321 | if (strcmp(dentry->d_name.name, kn->name) != 0) |
fd7b9f7b TH |
322 | goto out_bad; |
323 | ||
c637b8ac | 324 | /* The kernfs node has been moved to a different namespace */ |
adc5e8b5 | 325 | if (kn->parent && kernfs_ns_enabled(kn->parent) && |
c525aadd | 326 | kernfs_info(dentry->d_sb)->ns != kn->ns) |
fd7b9f7b TH |
327 | goto out_bad; |
328 | ||
a797bfc3 | 329 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
330 | out_valid: |
331 | return 1; | |
332 | out_bad: | |
a797bfc3 | 333 | mutex_unlock(&kernfs_mutex); |
19bbb926 TH |
334 | out_bad_unlocked: |
335 | /* | |
336 | * @dentry doesn't match the underlying kernfs node, drop the | |
337 | * dentry and force lookup. If we have submounts we must allow the | |
338 | * vfs caches to lie about the state of the filesystem to prevent | |
339 | * leaks and other nasty things, so use check_submounts_and_drop() | |
340 | * instead of d_drop(). | |
fd7b9f7b TH |
341 | */ |
342 | if (check_submounts_and_drop(dentry) != 0) | |
343 | goto out_valid; | |
344 | ||
345 | return 0; | |
346 | } | |
347 | ||
c637b8ac | 348 | static void kernfs_dop_release(struct dentry *dentry) |
fd7b9f7b TH |
349 | { |
350 | kernfs_put(dentry->d_fsdata); | |
351 | } | |
352 | ||
a797bfc3 | 353 | const struct dentry_operations kernfs_dops = { |
c637b8ac | 354 | .d_revalidate = kernfs_dop_revalidate, |
c637b8ac | 355 | .d_release = kernfs_dop_release, |
fd7b9f7b TH |
356 | }; |
357 | ||
c637b8ac | 358 | struct kernfs_node *kernfs_new_node(struct kernfs_root *root, const char *name, |
2063d608 | 359 | umode_t mode, unsigned flags) |
fd7b9f7b TH |
360 | { |
361 | char *dup_name = NULL; | |
324a56e1 | 362 | struct kernfs_node *kn; |
bc755553 | 363 | int ret; |
fd7b9f7b | 364 | |
2063d608 | 365 | if (!(flags & KERNFS_STATIC_NAME)) { |
fd7b9f7b TH |
366 | name = dup_name = kstrdup(name, GFP_KERNEL); |
367 | if (!name) | |
368 | return NULL; | |
369 | } | |
370 | ||
a797bfc3 | 371 | kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e1 | 372 | if (!kn) |
fd7b9f7b TH |
373 | goto err_out1; |
374 | ||
bc755553 TH |
375 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
376 | if (ret < 0) | |
fd7b9f7b | 377 | goto err_out2; |
adc5e8b5 | 378 | kn->ino = ret; |
fd7b9f7b | 379 | |
adc5e8b5 | 380 | atomic_set(&kn->count, 1); |
ae34372e TH |
381 | atomic_set(&kn->active, KN_DEACTIVATED_BIAS); |
382 | RB_CLEAR_NODE(&kn->rb); | |
fd7b9f7b | 383 | |
adc5e8b5 TH |
384 | kn->name = name; |
385 | kn->mode = mode; | |
ae34372e | 386 | kn->flags = flags; |
fd7b9f7b | 387 | |
324a56e1 | 388 | return kn; |
fd7b9f7b TH |
389 | |
390 | err_out2: | |
a797bfc3 | 391 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b TH |
392 | err_out1: |
393 | kfree(dup_name); | |
394 | return NULL; | |
395 | } | |
396 | ||
7653fe9d GKH |
397 | /** |
398 | * kernfs_addrm_start - prepare for kernfs_node add/remove | |
399 | * @acxt: pointer to kernfs_addrm_cxt to be used | |
400 | * | |
401 | * This function is called when the caller is about to add or remove | |
402 | * kernfs_node. This function acquires kernfs_mutex. @acxt is used | |
403 | * to keep and pass context to other addrm functions. | |
404 | * | |
405 | * LOCKING: | |
406 | * Kernel thread context (may sleep). kernfs_mutex is locked on | |
407 | * return. | |
408 | */ | |
409 | void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt) | |
410 | __acquires(kernfs_mutex) | |
411 | { | |
412 | memset(acxt, 0, sizeof(*acxt)); | |
413 | ||
414 | mutex_lock(&kernfs_mutex); | |
415 | } | |
416 | ||
fd7b9f7b | 417 | /** |
c637b8ac | 418 | * kernfs_add_one - add kernfs_node to parent without warning |
7653fe9d | 419 | * @acxt: addrm context to use |
324a56e1 TH |
420 | * @kn: kernfs_node to be added |
421 | * @parent: the parent kernfs_node to add @kn to | |
fd7b9f7b | 422 | * |
adc5e8b5 TH |
423 | * Get @parent and set @kn->parent to it and increment nlink of the |
424 | * parent inode if @kn is a directory and link into the children list | |
425 | * of the parent. | |
fd7b9f7b | 426 | * |
7653fe9d GKH |
427 | * This function should be called between calls to |
428 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be passed | |
429 | * the same @acxt as passed to kernfs_addrm_start(). | |
430 | * | |
431 | * LOCKING: | |
432 | * Determined by kernfs_addrm_start(). | |
433 | * | |
fd7b9f7b TH |
434 | * RETURNS: |
435 | * 0 on success, -EEXIST if entry with the given name already | |
436 | * exists. | |
437 | */ | |
7653fe9d GKH |
438 | int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn, |
439 | struct kernfs_node *parent) | |
fd7b9f7b | 440 | { |
7653fe9d | 441 | bool has_ns = kernfs_ns_enabled(parent); |
c525aadd | 442 | struct kernfs_iattrs *ps_iattr; |
fd7b9f7b TH |
443 | int ret; |
444 | ||
7653fe9d | 445 | WARN_ON_ONCE(atomic_read(&parent->active) < 0); |
99177a34 | 446 | |
7653fe9d GKH |
447 | if (has_ns != (bool)kn->ns) { |
448 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", | |
449 | has_ns ? "required" : "invalid", parent->name, kn->name); | |
450 | return -EINVAL; | |
451 | } | |
fd7b9f7b | 452 | |
df23fc39 | 453 | if (kernfs_type(parent) != KERNFS_DIR) |
7653fe9d | 454 | return -EINVAL; |
fd7b9f7b | 455 | |
c637b8ac | 456 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 457 | kn->parent = parent; |
324a56e1 | 458 | kernfs_get(parent); |
fd7b9f7b | 459 | |
c637b8ac | 460 | ret = kernfs_link_sibling(kn); |
fd7b9f7b | 461 | if (ret) |
7653fe9d | 462 | return ret; |
fd7b9f7b TH |
463 | |
464 | /* Update timestamps on the parent */ | |
adc5e8b5 | 465 | ps_iattr = parent->iattr; |
fd7b9f7b TH |
466 | if (ps_iattr) { |
467 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
468 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
469 | } | |
470 | ||
471 | /* Mark the entry added into directory tree */ | |
ae34372e | 472 | atomic_sub(KN_DEACTIVATED_BIAS, &kn->active); |
7653fe9d GKH |
473 | return 0; |
474 | } | |
475 | ||
476 | /** | |
477 | * kernfs_addrm_finish - finish up kernfs_node add/remove | |
478 | * @acxt: addrm context to finish up | |
479 | * | |
480 | * Finish up kernfs_node add/remove. Resources acquired by | |
481 | * kernfs_addrm_start() are released and removed kernfs_nodes are | |
482 | * cleaned up. | |
483 | * | |
484 | * LOCKING: | |
485 | * kernfs_mutex is released. | |
486 | */ | |
487 | void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt) | |
488 | __releases(kernfs_mutex) | |
489 | { | |
490 | /* release resources acquired by kernfs_addrm_start() */ | |
a797bfc3 | 491 | mutex_unlock(&kernfs_mutex); |
7653fe9d GKH |
492 | |
493 | /* kill removed kernfs_nodes */ | |
494 | while (acxt->removed) { | |
495 | struct kernfs_node *kn = acxt->removed; | |
496 | ||
497 | acxt->removed = kn->u.removed_list; | |
498 | ||
55f6e30d | 499 | kernfs_unmap_bin_file(kn); |
7653fe9d GKH |
500 | kernfs_put(kn); |
501 | } | |
fd7b9f7b TH |
502 | } |
503 | ||
504 | /** | |
324a56e1 TH |
505 | * kernfs_find_ns - find kernfs_node with the given name |
506 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
507 | * @name: name to look for |
508 | * @ns: the namespace tag to use | |
509 | * | |
324a56e1 TH |
510 | * Look for kernfs_node with name @name under @parent. Returns pointer to |
511 | * the found kernfs_node on success, %NULL on failure. | |
fd7b9f7b | 512 | */ |
324a56e1 TH |
513 | static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, |
514 | const unsigned char *name, | |
515 | const void *ns) | |
fd7b9f7b | 516 | { |
adc5e8b5 | 517 | struct rb_node *node = parent->dir.children.rb_node; |
ac9bba03 | 518 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
519 | unsigned int hash; |
520 | ||
a797bfc3 | 521 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
522 | |
523 | if (has_ns != (bool)ns) { | |
c637b8ac | 524 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", |
adc5e8b5 | 525 | has_ns ? "required" : "invalid", parent->name, name); |
fd7b9f7b TH |
526 | return NULL; |
527 | } | |
528 | ||
c637b8ac | 529 | hash = kernfs_name_hash(name, ns); |
fd7b9f7b | 530 | while (node) { |
324a56e1 | 531 | struct kernfs_node *kn; |
fd7b9f7b TH |
532 | int result; |
533 | ||
324a56e1 | 534 | kn = rb_to_kn(node); |
c637b8ac | 535 | result = kernfs_name_compare(hash, name, ns, kn); |
fd7b9f7b TH |
536 | if (result < 0) |
537 | node = node->rb_left; | |
538 | else if (result > 0) | |
539 | node = node->rb_right; | |
540 | else | |
324a56e1 | 541 | return kn; |
fd7b9f7b TH |
542 | } |
543 | return NULL; | |
544 | } | |
545 | ||
546 | /** | |
324a56e1 TH |
547 | * kernfs_find_and_get_ns - find and get kernfs_node with the given name |
548 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
549 | * @name: name to look for |
550 | * @ns: the namespace tag to use | |
551 | * | |
324a56e1 | 552 | * Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b | 553 | * if found. This function may sleep and returns pointer to the found |
324a56e1 | 554 | * kernfs_node on success, %NULL on failure. |
fd7b9f7b | 555 | */ |
324a56e1 TH |
556 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
557 | const char *name, const void *ns) | |
fd7b9f7b | 558 | { |
324a56e1 | 559 | struct kernfs_node *kn; |
fd7b9f7b | 560 | |
a797bfc3 | 561 | mutex_lock(&kernfs_mutex); |
324a56e1 TH |
562 | kn = kernfs_find_ns(parent, name, ns); |
563 | kernfs_get(kn); | |
a797bfc3 | 564 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 565 | |
324a56e1 | 566 | return kn; |
fd7b9f7b TH |
567 | } |
568 | EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); | |
569 | ||
ba7443bc TH |
570 | /** |
571 | * kernfs_create_root - create a new kernfs hierarchy | |
80b9bbef | 572 | * @kdops: optional directory syscall operations for the hierarchy |
ba7443bc TH |
573 | * @priv: opaque data associated with the new directory |
574 | * | |
575 | * Returns the root of the new hierarchy on success, ERR_PTR() value on | |
576 | * failure. | |
577 | */ | |
80b9bbef | 578 | struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv) |
ba7443bc TH |
579 | { |
580 | struct kernfs_root *root; | |
324a56e1 | 581 | struct kernfs_node *kn; |
ba7443bc TH |
582 | |
583 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
584 | if (!root) | |
585 | return ERR_PTR(-ENOMEM); | |
586 | ||
bc755553 TH |
587 | ida_init(&root->ino_ida); |
588 | ||
c637b8ac | 589 | kn = kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, KERNFS_DIR); |
324a56e1 | 590 | if (!kn) { |
bc755553 | 591 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
592 | kfree(root); |
593 | return ERR_PTR(-ENOMEM); | |
594 | } | |
595 | ||
ae34372e | 596 | atomic_sub(KN_DEACTIVATED_BIAS, &kn->active); |
324a56e1 | 597 | kn->priv = priv; |
adc5e8b5 | 598 | kn->dir.root = root; |
ba7443bc | 599 | |
80b9bbef | 600 | root->dir_ops = kdops; |
324a56e1 | 601 | root->kn = kn; |
ea1c472d | 602 | init_waitqueue_head(&root->deactivate_waitq); |
ba7443bc TH |
603 | |
604 | return root; | |
605 | } | |
606 | ||
607 | /** | |
608 | * kernfs_destroy_root - destroy a kernfs hierarchy | |
609 | * @root: root of the hierarchy to destroy | |
610 | * | |
611 | * Destroy the hierarchy anchored at @root by removing all existing | |
612 | * directories and destroying @root. | |
613 | */ | |
614 | void kernfs_destroy_root(struct kernfs_root *root) | |
615 | { | |
324a56e1 | 616 | kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc TH |
617 | } |
618 | ||
fd7b9f7b TH |
619 | /** |
620 | * kernfs_create_dir_ns - create a directory | |
621 | * @parent: parent in which to create a new directory | |
622 | * @name: name of the new directory | |
bb8b9d09 | 623 | * @mode: mode of the new directory |
fd7b9f7b TH |
624 | * @priv: opaque data associated with the new directory |
625 | * @ns: optional namespace tag of the directory | |
626 | * | |
627 | * Returns the created node on success, ERR_PTR() value on failure. | |
628 | */ | |
324a56e1 | 629 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d09 TH |
630 | const char *name, umode_t mode, |
631 | void *priv, const void *ns) | |
fd7b9f7b | 632 | { |
7653fe9d | 633 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 634 | struct kernfs_node *kn; |
fd7b9f7b TH |
635 | int rc; |
636 | ||
637 | /* allocate */ | |
bb8b9d09 TH |
638 | kn = kernfs_new_node(kernfs_root(parent), name, mode | S_IFDIR, |
639 | KERNFS_DIR); | |
324a56e1 | 640 | if (!kn) |
fd7b9f7b TH |
641 | return ERR_PTR(-ENOMEM); |
642 | ||
adc5e8b5 TH |
643 | kn->dir.root = parent->dir.root; |
644 | kn->ns = ns; | |
324a56e1 | 645 | kn->priv = priv; |
fd7b9f7b TH |
646 | |
647 | /* link in */ | |
7653fe9d GKH |
648 | rc = -ENOENT; |
649 | if (kernfs_get_active(parent)) { | |
650 | kernfs_addrm_start(&acxt); | |
651 | rc = kernfs_add_one(&acxt, kn, parent); | |
652 | kernfs_addrm_finish(&acxt); | |
653 | kernfs_put_active(parent); | |
654 | } | |
655 | ||
fd7b9f7b | 656 | if (!rc) |
324a56e1 | 657 | return kn; |
fd7b9f7b | 658 | |
324a56e1 | 659 | kernfs_put(kn); |
fd7b9f7b TH |
660 | return ERR_PTR(rc); |
661 | } | |
662 | ||
c637b8ac TH |
663 | static struct dentry *kernfs_iop_lookup(struct inode *dir, |
664 | struct dentry *dentry, | |
665 | unsigned int flags) | |
fd7b9f7b | 666 | { |
19bbb926 | 667 | struct dentry *ret; |
324a56e1 TH |
668 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
669 | struct kernfs_node *kn; | |
fd7b9f7b TH |
670 | struct inode *inode; |
671 | const void *ns = NULL; | |
672 | ||
a797bfc3 | 673 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 674 | |
324a56e1 | 675 | if (kernfs_ns_enabled(parent)) |
c525aadd | 676 | ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b | 677 | |
324a56e1 | 678 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
679 | |
680 | /* no such entry */ | |
324a56e1 | 681 | if (!kn) { |
19bbb926 | 682 | ret = NULL; |
fd7b9f7b TH |
683 | goto out_unlock; |
684 | } | |
324a56e1 TH |
685 | kernfs_get(kn); |
686 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
687 | |
688 | /* attach dentry and inode */ | |
c637b8ac | 689 | inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
690 | if (!inode) { |
691 | ret = ERR_PTR(-ENOMEM); | |
692 | goto out_unlock; | |
693 | } | |
694 | ||
695 | /* instantiate and hash dentry */ | |
696 | ret = d_materialise_unique(dentry, inode); | |
697 | out_unlock: | |
a797bfc3 | 698 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
699 | return ret; |
700 | } | |
701 | ||
80b9bbef TH |
702 | static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, |
703 | umode_t mode) | |
704 | { | |
705 | struct kernfs_node *parent = dir->i_private; | |
706 | struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops; | |
707 | ||
708 | if (!kdops || !kdops->mkdir) | |
709 | return -EPERM; | |
710 | ||
711 | return kdops->mkdir(parent, dentry->d_name.name, mode); | |
712 | } | |
713 | ||
714 | static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) | |
715 | { | |
716 | struct kernfs_node *kn = dentry->d_fsdata; | |
717 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
718 | ||
719 | if (!kdops || !kdops->rmdir) | |
720 | return -EPERM; | |
721 | ||
722 | return kdops->rmdir(kn); | |
723 | } | |
724 | ||
725 | static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, | |
726 | struct inode *new_dir, struct dentry *new_dentry) | |
727 | { | |
728 | struct kernfs_node *kn = old_dentry->d_fsdata; | |
729 | struct kernfs_node *new_parent = new_dir->i_private; | |
730 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
731 | ||
732 | if (!kdops || !kdops->rename) | |
733 | return -EPERM; | |
734 | ||
735 | return kdops->rename(kn, new_parent, new_dentry->d_name.name); | |
736 | } | |
737 | ||
a797bfc3 | 738 | const struct inode_operations kernfs_dir_iops = { |
c637b8ac TH |
739 | .lookup = kernfs_iop_lookup, |
740 | .permission = kernfs_iop_permission, | |
741 | .setattr = kernfs_iop_setattr, | |
742 | .getattr = kernfs_iop_getattr, | |
743 | .setxattr = kernfs_iop_setxattr, | |
744 | .removexattr = kernfs_iop_removexattr, | |
745 | .getxattr = kernfs_iop_getxattr, | |
746 | .listxattr = kernfs_iop_listxattr, | |
80b9bbef TH |
747 | |
748 | .mkdir = kernfs_iop_mkdir, | |
749 | .rmdir = kernfs_iop_rmdir, | |
750 | .rename = kernfs_iop_rename, | |
fd7b9f7b TH |
751 | }; |
752 | ||
c637b8ac | 753 | static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 754 | { |
324a56e1 | 755 | struct kernfs_node *last; |
fd7b9f7b TH |
756 | |
757 | while (true) { | |
758 | struct rb_node *rbn; | |
759 | ||
760 | last = pos; | |
761 | ||
df23fc39 | 762 | if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b TH |
763 | break; |
764 | ||
adc5e8b5 | 765 | rbn = rb_first(&pos->dir.children); |
fd7b9f7b TH |
766 | if (!rbn) |
767 | break; | |
768 | ||
324a56e1 | 769 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
770 | } |
771 | ||
772 | return last; | |
773 | } | |
774 | ||
775 | /** | |
c637b8ac | 776 | * kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b | 777 | * @pos: the current position (%NULL to initiate traversal) |
324a56e1 | 778 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
779 | * |
780 | * Find the next descendant to visit for post-order traversal of @root's | |
781 | * descendants. @root is included in the iteration and the last node to be | |
782 | * visited. | |
783 | */ | |
c637b8ac TH |
784 | static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, |
785 | struct kernfs_node *root) | |
fd7b9f7b TH |
786 | { |
787 | struct rb_node *rbn; | |
788 | ||
a797bfc3 | 789 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
790 | |
791 | /* if first iteration, visit leftmost descendant which may be root */ | |
792 | if (!pos) | |
c637b8ac | 793 | return kernfs_leftmost_descendant(root); |
fd7b9f7b TH |
794 | |
795 | /* if we visited @root, we're done */ | |
796 | if (pos == root) | |
797 | return NULL; | |
798 | ||
799 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
adc5e8b5 | 800 | rbn = rb_next(&pos->rb); |
fd7b9f7b | 801 | if (rbn) |
c637b8ac | 802 | return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
803 | |
804 | /* no sibling left, visit parent */ | |
adc5e8b5 | 805 | return pos->parent; |
fd7b9f7b TH |
806 | } |
807 | ||
45a140e5 TH |
808 | static void __kernfs_deactivate(struct kernfs_node *kn) |
809 | { | |
810 | struct kernfs_node *pos; | |
811 | ||
812 | lockdep_assert_held(&kernfs_mutex); | |
813 | ||
814 | /* prevent any new usage under @kn by deactivating all nodes */ | |
815 | pos = NULL; | |
816 | while ((pos = kernfs_next_descendant_post(pos, kn))) { | |
9b0925a6 | 817 | if (atomic_read(&pos->active) >= 0) { |
45a140e5 TH |
818 | atomic_add(KN_DEACTIVATED_BIAS, &pos->active); |
819 | pos->flags |= KERNFS_JUST_DEACTIVATED; | |
820 | } | |
821 | } | |
822 | ||
823 | /* | |
824 | * Drain the subtree. If kernfs_drain() blocked to drain, which is | |
825 | * indicated by %true return, it temporarily released kernfs_mutex | |
826 | * and the rbtree might have been modified inbetween breaking our | |
827 | * future walk. Restart the walk after each %true return. | |
828 | */ | |
829 | pos = NULL; | |
830 | while ((pos = kernfs_next_descendant_post(pos, kn))) { | |
831 | bool drained; | |
832 | ||
833 | kernfs_get(pos); | |
834 | drained = kernfs_drain(pos); | |
835 | kernfs_put(pos); | |
836 | if (drained) | |
837 | pos = NULL; | |
838 | } | |
839 | } | |
840 | ||
7653fe9d GKH |
841 | static void __kernfs_remove(struct kernfs_addrm_cxt *acxt, |
842 | struct kernfs_node *kn) | |
fd7b9f7b | 843 | { |
45a140e5 TH |
844 | struct kernfs_node *pos; |
845 | ||
846 | lockdep_assert_held(&kernfs_mutex); | |
fd7b9f7b | 847 | |
ce9b499c GKH |
848 | if (!kn) |
849 | return; | |
850 | ||
c637b8ac | 851 | pr_debug("kernfs %s: removing\n", kn->name); |
fd7b9f7b | 852 | |
45a140e5 TH |
853 | __kernfs_deactivate(kn); |
854 | ||
855 | /* unlink the subtree node-by-node */ | |
fd7b9f7b | 856 | do { |
55f6e30d | 857 | struct kernfs_iattrs *ps_iattr; |
f601f9a2 | 858 | |
55f6e30d | 859 | pos = kernfs_leftmost_descendant(kn); |
f601f9a2 | 860 | |
55f6e30d GKH |
861 | if (pos->parent) { |
862 | kernfs_unlink_sibling(pos); | |
45a140e5 TH |
863 | |
864 | /* update timestamps on the parent */ | |
55f6e30d | 865 | ps_iattr = pos->parent->iattr; |
45a140e5 TH |
866 | if (ps_iattr) { |
867 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
868 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
869 | } | |
870 | } | |
871 | ||
55f6e30d GKH |
872 | pos->u.removed_list = acxt->removed; |
873 | acxt->removed = pos; | |
45a140e5 | 874 | } while (pos != kn); |
fd7b9f7b TH |
875 | } |
876 | ||
877 | /** | |
324a56e1 TH |
878 | * kernfs_remove - remove a kernfs_node recursively |
879 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 880 | * |
324a56e1 | 881 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 882 | */ |
324a56e1 | 883 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 884 | { |
7653fe9d GKH |
885 | struct kernfs_addrm_cxt acxt; |
886 | ||
887 | kernfs_addrm_start(&acxt); | |
888 | __kernfs_remove(&acxt, kn); | |
889 | kernfs_addrm_finish(&acxt); | |
fd7b9f7b TH |
890 | } |
891 | ||
892 | /** | |
324a56e1 TH |
893 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
894 | * @parent: parent of the target | |
895 | * @name: name of the kernfs_node to remove | |
896 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 897 | * |
324a56e1 TH |
898 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
899 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 900 | */ |
324a56e1 | 901 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
902 | const void *ns) |
903 | { | |
7653fe9d | 904 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 905 | struct kernfs_node *kn; |
fd7b9f7b | 906 | |
324a56e1 | 907 | if (!parent) { |
c637b8ac | 908 | WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n", |
fd7b9f7b TH |
909 | name); |
910 | return -ENOENT; | |
911 | } | |
912 | ||
7653fe9d | 913 | kernfs_addrm_start(&acxt); |
fd7b9f7b | 914 | |
324a56e1 TH |
915 | kn = kernfs_find_ns(parent, name, ns); |
916 | if (kn) | |
7653fe9d | 917 | __kernfs_remove(&acxt, kn); |
fd7b9f7b | 918 | |
7653fe9d | 919 | kernfs_addrm_finish(&acxt); |
fd7b9f7b | 920 | |
324a56e1 | 921 | if (kn) |
fd7b9f7b TH |
922 | return 0; |
923 | else | |
924 | return -ENOENT; | |
925 | } | |
926 | ||
927 | /** | |
928 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 929 | * @kn: target node |
fd7b9f7b TH |
930 | * @new_parent: new parent to put @sd under |
931 | * @new_name: new name | |
932 | * @new_ns: new namespace tag | |
933 | */ | |
324a56e1 | 934 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
935 | const char *new_name, const void *new_ns) |
936 | { | |
937 | int error; | |
938 | ||
d0ae3d43 | 939 | error = -ENOENT; |
ae34372e | 940 | if (!kernfs_get_active(new_parent)) |
d0ae3d43 | 941 | goto out; |
ae34372e TH |
942 | if (!kernfs_get_active(kn)) |
943 | goto out_put_new_parent; | |
944 | ||
945 | mutex_lock(&kernfs_mutex); | |
d0ae3d43 | 946 | |
fd7b9f7b | 947 | error = 0; |
adc5e8b5 TH |
948 | if ((kn->parent == new_parent) && (kn->ns == new_ns) && |
949 | (strcmp(kn->name, new_name) == 0)) | |
ae34372e | 950 | goto out_unlock; /* nothing to rename */ |
fd7b9f7b TH |
951 | |
952 | error = -EEXIST; | |
953 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
ae34372e | 954 | goto out_unlock; |
fd7b9f7b | 955 | |
324a56e1 | 956 | /* rename kernfs_node */ |
adc5e8b5 | 957 | if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b TH |
958 | error = -ENOMEM; |
959 | new_name = kstrdup(new_name, GFP_KERNEL); | |
960 | if (!new_name) | |
ae34372e | 961 | goto out_unlock; |
fd7b9f7b | 962 | |
47a52e91 TH |
963 | if (kn->flags & KERNFS_STATIC_NAME) |
964 | kn->flags &= ~KERNFS_STATIC_NAME; | |
965 | else | |
966 | kfree(kn->name); | |
967 | ||
adc5e8b5 | 968 | kn->name = new_name; |
fd7b9f7b TH |
969 | } |
970 | ||
971 | /* | |
972 | * Move to the appropriate place in the appropriate directories rbtree. | |
973 | */ | |
c637b8ac | 974 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 975 | kernfs_get(new_parent); |
adc5e8b5 TH |
976 | kernfs_put(kn->parent); |
977 | kn->ns = new_ns; | |
c637b8ac | 978 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 979 | kn->parent = new_parent; |
c637b8ac | 980 | kernfs_link_sibling(kn); |
fd7b9f7b TH |
981 | |
982 | error = 0; | |
ae34372e | 983 | out_unlock: |
a797bfc3 | 984 | mutex_unlock(&kernfs_mutex); |
ae34372e TH |
985 | kernfs_put_active(kn); |
986 | out_put_new_parent: | |
987 | kernfs_put_active(new_parent); | |
988 | out: | |
fd7b9f7b TH |
989 | return error; |
990 | } | |
991 | ||
fd7b9f7b | 992 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 993 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 994 | { |
adc5e8b5 | 995 | return (kn->mode >> 12) & 15; |
fd7b9f7b TH |
996 | } |
997 | ||
c637b8ac | 998 | static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b TH |
999 | { |
1000 | kernfs_put(filp->private_data); | |
1001 | return 0; | |
1002 | } | |
1003 | ||
c637b8ac | 1004 | static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e1 | 1005 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b TH |
1006 | { |
1007 | if (pos) { | |
ae34372e | 1008 | int valid = pos->parent == parent && hash == pos->hash; |
fd7b9f7b TH |
1009 | kernfs_put(pos); |
1010 | if (!valid) | |
1011 | pos = NULL; | |
1012 | } | |
1013 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
adc5e8b5 | 1014 | struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b | 1015 | while (node) { |
324a56e1 | 1016 | pos = rb_to_kn(node); |
fd7b9f7b | 1017 | |
adc5e8b5 | 1018 | if (hash < pos->hash) |
fd7b9f7b | 1019 | node = node->rb_left; |
adc5e8b5 | 1020 | else if (hash > pos->hash) |
fd7b9f7b TH |
1021 | node = node->rb_right; |
1022 | else | |
1023 | break; | |
1024 | } | |
1025 | } | |
1026 | /* Skip over entries in the wrong namespace */ | |
adc5e8b5 TH |
1027 | while (pos && pos->ns != ns) { |
1028 | struct rb_node *node = rb_next(&pos->rb); | |
fd7b9f7b TH |
1029 | if (!node) |
1030 | pos = NULL; | |
1031 | else | |
324a56e1 | 1032 | pos = rb_to_kn(node); |
fd7b9f7b TH |
1033 | } |
1034 | return pos; | |
1035 | } | |
1036 | ||
c637b8ac | 1037 | static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e1 | 1038 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b | 1039 | { |
c637b8ac | 1040 | pos = kernfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
1041 | if (pos) |
1042 | do { | |
adc5e8b5 | 1043 | struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b TH |
1044 | if (!node) |
1045 | pos = NULL; | |
1046 | else | |
324a56e1 | 1047 | pos = rb_to_kn(node); |
adc5e8b5 | 1048 | } while (pos && pos->ns != ns); |
fd7b9f7b TH |
1049 | return pos; |
1050 | } | |
1051 | ||
c637b8ac | 1052 | static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b TH |
1053 | { |
1054 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
1055 | struct kernfs_node *parent = dentry->d_fsdata; |
1056 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
1057 | const void *ns = NULL; |
1058 | ||
1059 | if (!dir_emit_dots(file, ctx)) | |
1060 | return 0; | |
a797bfc3 | 1061 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1062 | |
324a56e1 | 1063 | if (kernfs_ns_enabled(parent)) |
c525aadd | 1064 | ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b | 1065 | |
c637b8ac | 1066 | for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 1067 | pos; |
c637b8ac | 1068 | pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b5 | 1069 | const char *name = pos->name; |
fd7b9f7b TH |
1070 | unsigned int type = dt_type(pos); |
1071 | int len = strlen(name); | |
adc5e8b5 | 1072 | ino_t ino = pos->ino; |
fd7b9f7b | 1073 | |
adc5e8b5 | 1074 | ctx->pos = pos->hash; |
fd7b9f7b TH |
1075 | file->private_data = pos; |
1076 | kernfs_get(pos); | |
1077 | ||
a797bfc3 | 1078 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1079 | if (!dir_emit(ctx, name, len, ino, type)) |
1080 | return 0; | |
a797bfc3 | 1081 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1082 | } |
a797bfc3 | 1083 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1084 | file->private_data = NULL; |
1085 | ctx->pos = INT_MAX; | |
1086 | return 0; | |
1087 | } | |
1088 | ||
c637b8ac TH |
1089 | static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset, |
1090 | int whence) | |
fd7b9f7b TH |
1091 | { |
1092 | struct inode *inode = file_inode(file); | |
1093 | loff_t ret; | |
1094 | ||
1095 | mutex_lock(&inode->i_mutex); | |
1096 | ret = generic_file_llseek(file, offset, whence); | |
1097 | mutex_unlock(&inode->i_mutex); | |
1098 | ||
1099 | return ret; | |
1100 | } | |
1101 | ||
a797bfc3 | 1102 | const struct file_operations kernfs_dir_fops = { |
fd7b9f7b | 1103 | .read = generic_read_dir, |
c637b8ac TH |
1104 | .iterate = kernfs_fop_readdir, |
1105 | .release = kernfs_dir_fop_release, | |
1106 | .llseek = kernfs_dir_fop_llseek, | |
fd7b9f7b | 1107 | }; |