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 | |
abd54f02 | 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 | |
fd7b9f7b | 25 | /** |
c637b8ac | 26 | * kernfs_name_hash |
fd7b9f7b TH |
27 | * @name: Null terminated string to hash |
28 | * @ns: Namespace tag to hash | |
29 | * | |
30 | * Returns 31 bit hash of ns + name (so it fits in an off_t ) | |
31 | */ | |
c637b8ac | 32 | static unsigned int kernfs_name_hash(const char *name, const void *ns) |
fd7b9f7b TH |
33 | { |
34 | unsigned long hash = init_name_hash(); | |
35 | unsigned int len = strlen(name); | |
36 | while (len--) | |
37 | hash = partial_name_hash(*name++, hash); | |
38 | hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31)); | |
39 | hash &= 0x7fffffffU; | |
40 | /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ | |
41 | if (hash < 1) | |
42 | hash += 2; | |
43 | if (hash >= INT_MAX) | |
44 | hash = INT_MAX - 1; | |
45 | return hash; | |
46 | } | |
47 | ||
c637b8ac TH |
48 | static int kernfs_name_compare(unsigned int hash, const char *name, |
49 | const void *ns, const struct kernfs_node *kn) | |
fd7b9f7b | 50 | { |
adc5e8b5 TH |
51 | if (hash != kn->hash) |
52 | return hash - kn->hash; | |
53 | if (ns != kn->ns) | |
54 | return ns - kn->ns; | |
55 | return strcmp(name, kn->name); | |
fd7b9f7b TH |
56 | } |
57 | ||
c637b8ac TH |
58 | static int kernfs_sd_compare(const struct kernfs_node *left, |
59 | const struct kernfs_node *right) | |
fd7b9f7b | 60 | { |
c637b8ac | 61 | return kernfs_name_compare(left->hash, left->name, left->ns, right); |
fd7b9f7b TH |
62 | } |
63 | ||
64 | /** | |
c637b8ac | 65 | * kernfs_link_sibling - link kernfs_node into sibling rbtree |
324a56e1 | 66 | * @kn: kernfs_node of interest |
fd7b9f7b | 67 | * |
324a56e1 | 68 | * Link @kn into its sibling rbtree which starts from |
adc5e8b5 | 69 | * @kn->parent->dir.children. |
fd7b9f7b TH |
70 | * |
71 | * Locking: | |
a797bfc3 | 72 | * mutex_lock(kernfs_mutex) |
fd7b9f7b TH |
73 | * |
74 | * RETURNS: | |
75 | * 0 on susccess -EEXIST on failure. | |
76 | */ | |
c637b8ac | 77 | static int kernfs_link_sibling(struct kernfs_node *kn) |
fd7b9f7b | 78 | { |
adc5e8b5 | 79 | struct rb_node **node = &kn->parent->dir.children.rb_node; |
fd7b9f7b TH |
80 | struct rb_node *parent = NULL; |
81 | ||
df23fc39 | 82 | if (kernfs_type(kn) == KERNFS_DIR) |
adc5e8b5 | 83 | kn->parent->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; |
c637b8ac | 91 | result = kernfs_sd_compare(kn, pos); |
fd7b9f7b | 92 | if (result < 0) |
adc5e8b5 | 93 | node = &pos->rb.rb_left; |
fd7b9f7b | 94 | else if (result > 0) |
adc5e8b5 | 95 | node = &pos->rb.rb_right; |
fd7b9f7b TH |
96 | else |
97 | return -EEXIST; | |
98 | } | |
99 | /* add new node and rebalance the tree */ | |
adc5e8b5 TH |
100 | rb_link_node(&kn->rb, parent, node); |
101 | rb_insert_color(&kn->rb, &kn->parent->dir.children); | |
fd7b9f7b TH |
102 | return 0; |
103 | } | |
104 | ||
105 | /** | |
c637b8ac | 106 | * kernfs_unlink_sibling - unlink kernfs_node from sibling rbtree |
324a56e1 | 107 | * @kn: kernfs_node of interest |
fd7b9f7b | 108 | * |
35beab06 TH |
109 | * Try to unlink @kn from its sibling rbtree which starts from |
110 | * kn->parent->dir.children. Returns %true if @kn was actually | |
111 | * removed, %false if @kn wasn't on the rbtree. | |
fd7b9f7b TH |
112 | * |
113 | * Locking: | |
a797bfc3 | 114 | * mutex_lock(kernfs_mutex) |
fd7b9f7b | 115 | */ |
35beab06 | 116 | static bool kernfs_unlink_sibling(struct kernfs_node *kn) |
fd7b9f7b | 117 | { |
35beab06 TH |
118 | if (RB_EMPTY_NODE(&kn->rb)) |
119 | return false; | |
120 | ||
df23fc39 | 121 | if (kernfs_type(kn) == KERNFS_DIR) |
adc5e8b5 | 122 | kn->parent->dir.subdirs--; |
fd7b9f7b | 123 | |
adc5e8b5 | 124 | rb_erase(&kn->rb, &kn->parent->dir.children); |
35beab06 TH |
125 | RB_CLEAR_NODE(&kn->rb); |
126 | return true; | |
fd7b9f7b TH |
127 | } |
128 | ||
129 | /** | |
c637b8ac | 130 | * kernfs_get_active - get an active reference to kernfs_node |
324a56e1 | 131 | * @kn: kernfs_node to get an active reference to |
fd7b9f7b | 132 | * |
324a56e1 | 133 | * Get an active reference of @kn. This function is noop if @kn |
fd7b9f7b TH |
134 | * is NULL. |
135 | * | |
136 | * RETURNS: | |
324a56e1 | 137 | * Pointer to @kn on success, NULL on failure. |
fd7b9f7b | 138 | */ |
c637b8ac | 139 | struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) |
fd7b9f7b | 140 | { |
324a56e1 | 141 | if (unlikely(!kn)) |
fd7b9f7b TH |
142 | return NULL; |
143 | ||
f4b3e631 GKH |
144 | if (!atomic_inc_unless_negative(&kn->active)) |
145 | return NULL; | |
895a068a | 146 | |
0890147f | 147 | if (kn->flags & KERNFS_LOCKDEP) |
f4b3e631 GKH |
148 | rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_); |
149 | return kn; | |
fd7b9f7b TH |
150 | } |
151 | ||
152 | /** | |
c637b8ac | 153 | * kernfs_put_active - put an active reference to kernfs_node |
324a56e1 | 154 | * @kn: kernfs_node to put an active reference to |
fd7b9f7b | 155 | * |
324a56e1 | 156 | * Put an active reference to @kn. This function is noop if @kn |
fd7b9f7b TH |
157 | * is NULL. |
158 | */ | |
c637b8ac | 159 | void kernfs_put_active(struct kernfs_node *kn) |
fd7b9f7b | 160 | { |
abd54f02 | 161 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b TH |
162 | int v; |
163 | ||
324a56e1 | 164 | if (unlikely(!kn)) |
fd7b9f7b TH |
165 | return; |
166 | ||
0890147f | 167 | if (kn->flags & KERNFS_LOCKDEP) |
324a56e1 | 168 | rwsem_release(&kn->dep_map, 1, _RET_IP_); |
adc5e8b5 | 169 | v = atomic_dec_return(&kn->active); |
df23fc39 | 170 | if (likely(v != KN_DEACTIVATED_BIAS)) |
fd7b9f7b TH |
171 | return; |
172 | ||
abd54f02 | 173 | wake_up_all(&root->deactivate_waitq); |
fd7b9f7b TH |
174 | } |
175 | ||
176 | /** | |
798c75a0 GKH |
177 | * kernfs_deactivate - deactivate kernfs_node |
178 | * @kn: kernfs_node to deactivate | |
fd7b9f7b | 179 | * |
ccf02aaf TH |
180 | * Deny new active references, drain existing ones and nuke all |
181 | * existing mmaps. Mutiple removers may invoke this function | |
182 | * concurrently on @kn and all will return after deactivation and | |
183 | * draining are complete. | |
fd7b9f7b | 184 | */ |
798c75a0 | 185 | static void kernfs_deactivate(struct kernfs_node *kn) |
35beab06 | 186 | __releases(&kernfs_mutex) __acquires(&kernfs_mutex) |
fd7b9f7b | 187 | { |
abd54f02 | 188 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b | 189 | |
35beab06 | 190 | lockdep_assert_held(&kernfs_mutex); |
798c75a0 GKH |
191 | BUG_ON(!(kn->flags & KERNFS_REMOVED)); |
192 | ||
0890147f GKH |
193 | if (!(kernfs_type(kn) & KERNFS_ACTIVE_REF)) |
194 | return; | |
195 | ||
35beab06 TH |
196 | /* only the first invocation on @kn should deactivate it */ |
197 | if (atomic_read(&kn->active) >= 0) | |
198 | atomic_add(KN_DEACTIVATED_BIAS, &kn->active); | |
ea1c472d | 199 | |
35beab06 | 200 | mutex_unlock(&kernfs_mutex); |
abd54f02 | 201 | |
35beab06 TH |
202 | if (kn->flags & KERNFS_LOCKDEP) { |
203 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); | |
204 | if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS) | |
205 | lock_contended(&kn->dep_map, _RET_IP_); | |
206 | } | |
abd54f02 | 207 | |
35beab06 | 208 | /* but everyone should wait for draining */ |
abd54f02 TH |
209 | wait_event(root->deactivate_waitq, |
210 | atomic_read(&kn->active) == KN_DEACTIVATED_BIAS); | |
fd7b9f7b | 211 | |
a6607930 TH |
212 | if (kn->flags & KERNFS_LOCKDEP) { |
213 | lock_acquired(&kn->dep_map, _RET_IP_); | |
214 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
215 | } | |
35beab06 | 216 | |
ccf02aaf TH |
217 | kernfs_unmap_bin_file(kn); |
218 | ||
35beab06 | 219 | mutex_lock(&kernfs_mutex); |
fd7b9f7b TH |
220 | } |
221 | ||
fd7b9f7b | 222 | /** |
324a56e1 TH |
223 | * kernfs_get - get a reference count on a kernfs_node |
224 | * @kn: the target kernfs_node | |
fd7b9f7b | 225 | */ |
324a56e1 | 226 | void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b | 227 | { |
324a56e1 | 228 | if (kn) { |
adc5e8b5 TH |
229 | WARN_ON(!atomic_read(&kn->count)); |
230 | atomic_inc(&kn->count); | |
fd7b9f7b TH |
231 | } |
232 | } | |
233 | EXPORT_SYMBOL_GPL(kernfs_get); | |
234 | ||
235 | /** | |
324a56e1 TH |
236 | * kernfs_put - put a reference count on a kernfs_node |
237 | * @kn: the target kernfs_node | |
fd7b9f7b | 238 | * |
324a56e1 | 239 | * Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b | 240 | */ |
324a56e1 | 241 | void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b | 242 | { |
324a56e1 | 243 | struct kernfs_node *parent; |
ba7443bc | 244 | struct kernfs_root *root; |
fd7b9f7b | 245 | |
adc5e8b5 | 246 | if (!kn || !atomic_dec_and_test(&kn->count)) |
fd7b9f7b | 247 | return; |
324a56e1 | 248 | root = kernfs_root(kn); |
fd7b9f7b | 249 | repeat: |
798c75a0 | 250 | /* Moving/renaming is always done while holding reference. |
adc5e8b5 | 251 | * kn->parent won't change beneath us. |
fd7b9f7b | 252 | */ |
adc5e8b5 | 253 | parent = kn->parent; |
fd7b9f7b | 254 | |
798c75a0 GKH |
255 | WARN(!(kn->flags & KERNFS_REMOVED), "kernfs: free using entry: %s/%s\n", |
256 | parent ? parent->name : "", kn->name); | |
324a56e1 | 257 | |
df23fc39 | 258 | if (kernfs_type(kn) == KERNFS_LINK) |
adc5e8b5 | 259 | kernfs_put(kn->symlink.target_kn); |
2063d608 | 260 | if (!(kn->flags & KERNFS_STATIC_NAME)) |
adc5e8b5 TH |
261 | kfree(kn->name); |
262 | if (kn->iattr) { | |
263 | if (kn->iattr->ia_secdata) | |
264 | security_release_secctx(kn->iattr->ia_secdata, | |
265 | kn->iattr->ia_secdata_len); | |
266 | simple_xattrs_free(&kn->iattr->xattrs); | |
2322392b | 267 | } |
adc5e8b5 TH |
268 | kfree(kn->iattr); |
269 | ida_simple_remove(&root->ino_ida, kn->ino); | |
a797bfc3 | 270 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b | 271 | |
324a56e1 TH |
272 | kn = parent; |
273 | if (kn) { | |
adc5e8b5 | 274 | if (atomic_dec_and_test(&kn->count)) |
ba7443bc TH |
275 | goto repeat; |
276 | } else { | |
324a56e1 | 277 | /* just released the root kn, free @root too */ |
bc755553 | 278 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
279 | kfree(root); |
280 | } | |
fd7b9f7b TH |
281 | } |
282 | EXPORT_SYMBOL_GPL(kernfs_put); | |
283 | ||
c637b8ac | 284 | static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags) |
fd7b9f7b | 285 | { |
324a56e1 | 286 | struct kernfs_node *kn; |
fd7b9f7b TH |
287 | |
288 | if (flags & LOOKUP_RCU) | |
289 | return -ECHILD; | |
290 | ||
19bbb926 TH |
291 | /* Always perform fresh lookup for negatives */ |
292 | if (!dentry->d_inode) | |
293 | goto out_bad_unlocked; | |
294 | ||
324a56e1 | 295 | kn = dentry->d_fsdata; |
a797bfc3 | 296 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 297 | |
798c75a0 GKH |
298 | /* The kernfs node has been deleted */ |
299 | if (kn->flags & KERNFS_REMOVED) | |
fd7b9f7b TH |
300 | goto out_bad; |
301 | ||
c637b8ac | 302 | /* The kernfs node has been moved? */ |
adc5e8b5 | 303 | if (dentry->d_parent->d_fsdata != kn->parent) |
fd7b9f7b TH |
304 | goto out_bad; |
305 | ||
c637b8ac | 306 | /* The kernfs node has been renamed */ |
adc5e8b5 | 307 | if (strcmp(dentry->d_name.name, kn->name) != 0) |
fd7b9f7b TH |
308 | goto out_bad; |
309 | ||
c637b8ac | 310 | /* The kernfs node has been moved to a different namespace */ |
adc5e8b5 | 311 | if (kn->parent && kernfs_ns_enabled(kn->parent) && |
c525aadd | 312 | kernfs_info(dentry->d_sb)->ns != kn->ns) |
fd7b9f7b TH |
313 | goto out_bad; |
314 | ||
a797bfc3 | 315 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
316 | out_valid: |
317 | return 1; | |
318 | out_bad: | |
a797bfc3 | 319 | mutex_unlock(&kernfs_mutex); |
19bbb926 TH |
320 | out_bad_unlocked: |
321 | /* | |
322 | * @dentry doesn't match the underlying kernfs node, drop the | |
323 | * dentry and force lookup. If we have submounts we must allow the | |
324 | * vfs caches to lie about the state of the filesystem to prevent | |
325 | * leaks and other nasty things, so use check_submounts_and_drop() | |
326 | * instead of d_drop(). | |
fd7b9f7b TH |
327 | */ |
328 | if (check_submounts_and_drop(dentry) != 0) | |
329 | goto out_valid; | |
330 | ||
331 | return 0; | |
332 | } | |
333 | ||
c637b8ac | 334 | static void kernfs_dop_release(struct dentry *dentry) |
fd7b9f7b TH |
335 | { |
336 | kernfs_put(dentry->d_fsdata); | |
337 | } | |
338 | ||
a797bfc3 | 339 | const struct dentry_operations kernfs_dops = { |
c637b8ac | 340 | .d_revalidate = kernfs_dop_revalidate, |
c637b8ac | 341 | .d_release = kernfs_dop_release, |
fd7b9f7b TH |
342 | }; |
343 | ||
db4aad20 TH |
344 | static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, |
345 | const char *name, umode_t mode, | |
346 | unsigned flags) | |
fd7b9f7b TH |
347 | { |
348 | char *dup_name = NULL; | |
324a56e1 | 349 | struct kernfs_node *kn; |
bc755553 | 350 | int ret; |
fd7b9f7b | 351 | |
2063d608 | 352 | if (!(flags & KERNFS_STATIC_NAME)) { |
fd7b9f7b TH |
353 | name = dup_name = kstrdup(name, GFP_KERNEL); |
354 | if (!name) | |
355 | return NULL; | |
356 | } | |
357 | ||
a797bfc3 | 358 | kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e1 | 359 | if (!kn) |
fd7b9f7b TH |
360 | goto err_out1; |
361 | ||
bc755553 TH |
362 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
363 | if (ret < 0) | |
fd7b9f7b | 364 | goto err_out2; |
adc5e8b5 | 365 | kn->ino = ret; |
fd7b9f7b | 366 | |
adc5e8b5 | 367 | atomic_set(&kn->count, 1); |
798c75a0 | 368 | atomic_set(&kn->active, 0); |
35beab06 | 369 | RB_CLEAR_NODE(&kn->rb); |
fd7b9f7b | 370 | |
adc5e8b5 TH |
371 | kn->name = name; |
372 | kn->mode = mode; | |
798c75a0 | 373 | kn->flags = flags | KERNFS_REMOVED; |
fd7b9f7b | 374 | |
324a56e1 | 375 | return kn; |
fd7b9f7b TH |
376 | |
377 | err_out2: | |
a797bfc3 | 378 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b TH |
379 | err_out1: |
380 | kfree(dup_name); | |
381 | return NULL; | |
382 | } | |
383 | ||
db4aad20 TH |
384 | struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, |
385 | const char *name, umode_t mode, | |
386 | unsigned flags) | |
387 | { | |
388 | struct kernfs_node *kn; | |
389 | ||
390 | kn = __kernfs_new_node(kernfs_root(parent), name, mode, flags); | |
391 | if (kn) { | |
392 | kernfs_get(parent); | |
393 | kn->parent = parent; | |
394 | } | |
395 | return kn; | |
396 | } | |
397 | ||
fd7b9f7b | 398 | /** |
c637b8ac | 399 | * kernfs_add_one - add kernfs_node to parent without warning |
324a56e1 | 400 | * @kn: kernfs_node to be added |
fd7b9f7b | 401 | * |
db4aad20 TH |
402 | * The caller must already have initialized @kn->parent. This |
403 | * function increments nlink of the parent's inode if @kn is a | |
404 | * directory and link into the children list of the parent. | |
fd7b9f7b | 405 | * |
fd7b9f7b TH |
406 | * RETURNS: |
407 | * 0 on success, -EEXIST if entry with the given name already | |
408 | * exists. | |
409 | */ | |
988cd7af | 410 | int kernfs_add_one(struct kernfs_node *kn) |
fd7b9f7b | 411 | { |
db4aad20 | 412 | struct kernfs_node *parent = kn->parent; |
c525aadd | 413 | struct kernfs_iattrs *ps_iattr; |
988cd7af | 414 | bool has_ns; |
fd7b9f7b TH |
415 | int ret; |
416 | ||
988cd7af TH |
417 | mutex_lock(&kernfs_mutex); |
418 | ||
419 | ret = -EINVAL; | |
420 | has_ns = kernfs_ns_enabled(parent); | |
421 | if (WARN(has_ns != (bool)kn->ns, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", | |
422 | has_ns ? "required" : "invalid", parent->name, kn->name)) | |
423 | goto out_unlock; | |
fd7b9f7b | 424 | |
df23fc39 | 425 | if (kernfs_type(parent) != KERNFS_DIR) |
988cd7af | 426 | goto out_unlock; |
fd7b9f7b | 427 | |
988cd7af | 428 | ret = -ENOENT; |
798c75a0 | 429 | if (parent->flags & KERNFS_REMOVED) |
988cd7af | 430 | goto out_unlock; |
798c75a0 | 431 | |
c637b8ac | 432 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
fd7b9f7b | 433 | |
c637b8ac | 434 | ret = kernfs_link_sibling(kn); |
fd7b9f7b | 435 | if (ret) |
988cd7af | 436 | goto out_unlock; |
fd7b9f7b TH |
437 | |
438 | /* Update timestamps on the parent */ | |
adc5e8b5 | 439 | ps_iattr = parent->iattr; |
fd7b9f7b TH |
440 | if (ps_iattr) { |
441 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
442 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
443 | } | |
444 | ||
445 | /* Mark the entry added into directory tree */ | |
798c75a0 | 446 | kn->flags &= ~KERNFS_REMOVED; |
988cd7af TH |
447 | ret = 0; |
448 | out_unlock: | |
a797bfc3 | 449 | mutex_unlock(&kernfs_mutex); |
988cd7af | 450 | return ret; |
fd7b9f7b TH |
451 | } |
452 | ||
453 | /** | |
324a56e1 TH |
454 | * kernfs_find_ns - find kernfs_node with the given name |
455 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
456 | * @name: name to look for |
457 | * @ns: the namespace tag to use | |
458 | * | |
324a56e1 TH |
459 | * Look for kernfs_node with name @name under @parent. Returns pointer to |
460 | * the found kernfs_node on success, %NULL on failure. | |
fd7b9f7b | 461 | */ |
324a56e1 TH |
462 | static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, |
463 | const unsigned char *name, | |
464 | const void *ns) | |
fd7b9f7b | 465 | { |
adc5e8b5 | 466 | struct rb_node *node = parent->dir.children.rb_node; |
ac9bba03 | 467 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
468 | unsigned int hash; |
469 | ||
a797bfc3 | 470 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
471 | |
472 | if (has_ns != (bool)ns) { | |
c637b8ac | 473 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", |
adc5e8b5 | 474 | has_ns ? "required" : "invalid", parent->name, name); |
fd7b9f7b TH |
475 | return NULL; |
476 | } | |
477 | ||
c637b8ac | 478 | hash = kernfs_name_hash(name, ns); |
fd7b9f7b | 479 | while (node) { |
324a56e1 | 480 | struct kernfs_node *kn; |
fd7b9f7b TH |
481 | int result; |
482 | ||
324a56e1 | 483 | kn = rb_to_kn(node); |
c637b8ac | 484 | result = kernfs_name_compare(hash, name, ns, kn); |
fd7b9f7b TH |
485 | if (result < 0) |
486 | node = node->rb_left; | |
487 | else if (result > 0) | |
488 | node = node->rb_right; | |
489 | else | |
324a56e1 | 490 | return kn; |
fd7b9f7b TH |
491 | } |
492 | return NULL; | |
493 | } | |
494 | ||
495 | /** | |
324a56e1 TH |
496 | * kernfs_find_and_get_ns - find and get kernfs_node with the given name |
497 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
498 | * @name: name to look for |
499 | * @ns: the namespace tag to use | |
500 | * | |
324a56e1 | 501 | * Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b | 502 | * if found. This function may sleep and returns pointer to the found |
324a56e1 | 503 | * kernfs_node on success, %NULL on failure. |
fd7b9f7b | 504 | */ |
324a56e1 TH |
505 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
506 | const char *name, const void *ns) | |
fd7b9f7b | 507 | { |
324a56e1 | 508 | struct kernfs_node *kn; |
fd7b9f7b | 509 | |
a797bfc3 | 510 | mutex_lock(&kernfs_mutex); |
324a56e1 TH |
511 | kn = kernfs_find_ns(parent, name, ns); |
512 | kernfs_get(kn); | |
a797bfc3 | 513 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 514 | |
324a56e1 | 515 | return kn; |
fd7b9f7b TH |
516 | } |
517 | EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); | |
518 | ||
ba7443bc TH |
519 | /** |
520 | * kernfs_create_root - create a new kernfs hierarchy | |
80b9bbef | 521 | * @kdops: optional directory syscall operations for the hierarchy |
ba7443bc TH |
522 | * @priv: opaque data associated with the new directory |
523 | * | |
524 | * Returns the root of the new hierarchy on success, ERR_PTR() value on | |
525 | * failure. | |
526 | */ | |
80b9bbef | 527 | struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv) |
ba7443bc TH |
528 | { |
529 | struct kernfs_root *root; | |
324a56e1 | 530 | struct kernfs_node *kn; |
ba7443bc TH |
531 | |
532 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
533 | if (!root) | |
534 | return ERR_PTR(-ENOMEM); | |
535 | ||
bc755553 TH |
536 | ida_init(&root->ino_ida); |
537 | ||
db4aad20 TH |
538 | kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, |
539 | KERNFS_DIR); | |
324a56e1 | 540 | if (!kn) { |
bc755553 | 541 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
542 | kfree(root); |
543 | return ERR_PTR(-ENOMEM); | |
544 | } | |
545 | ||
798c75a0 | 546 | kn->flags &= ~KERNFS_REMOVED; |
324a56e1 | 547 | kn->priv = priv; |
adc5e8b5 | 548 | kn->dir.root = root; |
ba7443bc | 549 | |
80b9bbef | 550 | root->dir_ops = kdops; |
324a56e1 | 551 | root->kn = kn; |
abd54f02 | 552 | init_waitqueue_head(&root->deactivate_waitq); |
ba7443bc TH |
553 | |
554 | return root; | |
555 | } | |
556 | ||
557 | /** | |
558 | * kernfs_destroy_root - destroy a kernfs hierarchy | |
559 | * @root: root of the hierarchy to destroy | |
560 | * | |
561 | * Destroy the hierarchy anchored at @root by removing all existing | |
562 | * directories and destroying @root. | |
563 | */ | |
564 | void kernfs_destroy_root(struct kernfs_root *root) | |
565 | { | |
324a56e1 | 566 | kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc TH |
567 | } |
568 | ||
fd7b9f7b TH |
569 | /** |
570 | * kernfs_create_dir_ns - create a directory | |
571 | * @parent: parent in which to create a new directory | |
572 | * @name: name of the new directory | |
bb8b9d09 | 573 | * @mode: mode of the new directory |
fd7b9f7b TH |
574 | * @priv: opaque data associated with the new directory |
575 | * @ns: optional namespace tag of the directory | |
576 | * | |
577 | * Returns the created node on success, ERR_PTR() value on failure. | |
578 | */ | |
324a56e1 | 579 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d09 TH |
580 | const char *name, umode_t mode, |
581 | void *priv, const void *ns) | |
fd7b9f7b | 582 | { |
324a56e1 | 583 | struct kernfs_node *kn; |
fd7b9f7b TH |
584 | int rc; |
585 | ||
586 | /* allocate */ | |
db4aad20 | 587 | kn = kernfs_new_node(parent, name, mode | S_IFDIR, KERNFS_DIR); |
324a56e1 | 588 | if (!kn) |
fd7b9f7b TH |
589 | return ERR_PTR(-ENOMEM); |
590 | ||
adc5e8b5 TH |
591 | kn->dir.root = parent->dir.root; |
592 | kn->ns = ns; | |
324a56e1 | 593 | kn->priv = priv; |
fd7b9f7b TH |
594 | |
595 | /* link in */ | |
988cd7af | 596 | rc = kernfs_add_one(kn); |
fd7b9f7b | 597 | if (!rc) |
324a56e1 | 598 | return kn; |
fd7b9f7b | 599 | |
324a56e1 | 600 | kernfs_put(kn); |
fd7b9f7b TH |
601 | return ERR_PTR(rc); |
602 | } | |
603 | ||
c637b8ac TH |
604 | static struct dentry *kernfs_iop_lookup(struct inode *dir, |
605 | struct dentry *dentry, | |
606 | unsigned int flags) | |
fd7b9f7b | 607 | { |
19bbb926 | 608 | struct dentry *ret; |
324a56e1 TH |
609 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
610 | struct kernfs_node *kn; | |
fd7b9f7b TH |
611 | struct inode *inode; |
612 | const void *ns = NULL; | |
613 | ||
a797bfc3 | 614 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 615 | |
324a56e1 | 616 | if (kernfs_ns_enabled(parent)) |
c525aadd | 617 | ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b | 618 | |
324a56e1 | 619 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
620 | |
621 | /* no such entry */ | |
324a56e1 | 622 | if (!kn) { |
19bbb926 | 623 | ret = NULL; |
fd7b9f7b TH |
624 | goto out_unlock; |
625 | } | |
324a56e1 TH |
626 | kernfs_get(kn); |
627 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
628 | |
629 | /* attach dentry and inode */ | |
c637b8ac | 630 | inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
631 | if (!inode) { |
632 | ret = ERR_PTR(-ENOMEM); | |
633 | goto out_unlock; | |
634 | } | |
635 | ||
636 | /* instantiate and hash dentry */ | |
637 | ret = d_materialise_unique(dentry, inode); | |
638 | out_unlock: | |
a797bfc3 | 639 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
640 | return ret; |
641 | } | |
642 | ||
80b9bbef TH |
643 | static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, |
644 | umode_t mode) | |
645 | { | |
646 | struct kernfs_node *parent = dir->i_private; | |
647 | struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops; | |
648 | ||
649 | if (!kdops || !kdops->mkdir) | |
650 | return -EPERM; | |
651 | ||
652 | return kdops->mkdir(parent, dentry->d_name.name, mode); | |
653 | } | |
654 | ||
655 | static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) | |
656 | { | |
657 | struct kernfs_node *kn = dentry->d_fsdata; | |
658 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
659 | ||
660 | if (!kdops || !kdops->rmdir) | |
661 | return -EPERM; | |
662 | ||
663 | return kdops->rmdir(kn); | |
664 | } | |
665 | ||
666 | static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, | |
667 | struct inode *new_dir, struct dentry *new_dentry) | |
668 | { | |
669 | struct kernfs_node *kn = old_dentry->d_fsdata; | |
670 | struct kernfs_node *new_parent = new_dir->i_private; | |
671 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
672 | ||
673 | if (!kdops || !kdops->rename) | |
674 | return -EPERM; | |
675 | ||
676 | return kdops->rename(kn, new_parent, new_dentry->d_name.name); | |
677 | } | |
678 | ||
a797bfc3 | 679 | const struct inode_operations kernfs_dir_iops = { |
c637b8ac TH |
680 | .lookup = kernfs_iop_lookup, |
681 | .permission = kernfs_iop_permission, | |
682 | .setattr = kernfs_iop_setattr, | |
683 | .getattr = kernfs_iop_getattr, | |
684 | .setxattr = kernfs_iop_setxattr, | |
685 | .removexattr = kernfs_iop_removexattr, | |
686 | .getxattr = kernfs_iop_getxattr, | |
687 | .listxattr = kernfs_iop_listxattr, | |
80b9bbef TH |
688 | |
689 | .mkdir = kernfs_iop_mkdir, | |
690 | .rmdir = kernfs_iop_rmdir, | |
691 | .rename = kernfs_iop_rename, | |
fd7b9f7b TH |
692 | }; |
693 | ||
c637b8ac | 694 | static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 695 | { |
324a56e1 | 696 | struct kernfs_node *last; |
fd7b9f7b TH |
697 | |
698 | while (true) { | |
699 | struct rb_node *rbn; | |
700 | ||
701 | last = pos; | |
702 | ||
df23fc39 | 703 | if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b TH |
704 | break; |
705 | ||
adc5e8b5 | 706 | rbn = rb_first(&pos->dir.children); |
fd7b9f7b TH |
707 | if (!rbn) |
708 | break; | |
709 | ||
324a56e1 | 710 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
711 | } |
712 | ||
713 | return last; | |
714 | } | |
715 | ||
716 | /** | |
c637b8ac | 717 | * kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b | 718 | * @pos: the current position (%NULL to initiate traversal) |
324a56e1 | 719 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
720 | * |
721 | * Find the next descendant to visit for post-order traversal of @root's | |
722 | * descendants. @root is included in the iteration and the last node to be | |
723 | * visited. | |
724 | */ | |
c637b8ac TH |
725 | static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, |
726 | struct kernfs_node *root) | |
fd7b9f7b TH |
727 | { |
728 | struct rb_node *rbn; | |
729 | ||
a797bfc3 | 730 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
731 | |
732 | /* if first iteration, visit leftmost descendant which may be root */ | |
733 | if (!pos) | |
c637b8ac | 734 | return kernfs_leftmost_descendant(root); |
fd7b9f7b TH |
735 | |
736 | /* if we visited @root, we're done */ | |
737 | if (pos == root) | |
738 | return NULL; | |
739 | ||
740 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
adc5e8b5 | 741 | rbn = rb_next(&pos->rb); |
fd7b9f7b | 742 | if (rbn) |
c637b8ac | 743 | return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
744 | |
745 | /* no sibling left, visit parent */ | |
adc5e8b5 | 746 | return pos->parent; |
fd7b9f7b TH |
747 | } |
748 | ||
988cd7af | 749 | static void __kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 750 | { |
35beab06 TH |
751 | struct kernfs_node *pos; |
752 | ||
753 | lockdep_assert_held(&kernfs_mutex); | |
fd7b9f7b | 754 | |
ce9b499c GKH |
755 | if (!kn) |
756 | return; | |
757 | ||
c637b8ac | 758 | pr_debug("kernfs %s: removing\n", kn->name); |
fd7b9f7b | 759 | |
35beab06 TH |
760 | /* disable lookup and node creation under @kn */ |
761 | pos = NULL; | |
762 | while ((pos = kernfs_next_descendant_post(pos, kn))) | |
763 | pos->flags |= KERNFS_REMOVED; | |
764 | ||
765 | /* deactivate and unlink the subtree node-by-node */ | |
fd7b9f7b | 766 | do { |
35beab06 TH |
767 | pos = kernfs_leftmost_descendant(kn); |
768 | ||
769 | /* | |
770 | * kernfs_deactivate() drops kernfs_mutex temporarily and | |
771 | * @pos's base ref could have been put by someone else by | |
772 | * the time the function returns. Make sure it doesn't go | |
773 | * away underneath us. | |
774 | */ | |
775 | kernfs_get(pos); | |
776 | ||
777 | kernfs_deactivate(pos); | |
778 | ||
779 | /* | |
780 | * kernfs_unlink_sibling() succeeds once per node. Use it | |
781 | * to decide who's responsible for cleanups. | |
782 | */ | |
783 | if (!pos->parent || kernfs_unlink_sibling(pos)) { | |
784 | struct kernfs_iattrs *ps_iattr = | |
785 | pos->parent ? pos->parent->iattr : NULL; | |
786 | ||
787 | /* update timestamps on the parent */ | |
788 | if (ps_iattr) { | |
789 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
790 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
791 | } | |
792 | ||
988cd7af | 793 | kernfs_put(pos); |
35beab06 TH |
794 | } |
795 | ||
796 | kernfs_put(pos); | |
797 | } while (pos != kn); | |
fd7b9f7b TH |
798 | } |
799 | ||
800 | /** | |
324a56e1 TH |
801 | * kernfs_remove - remove a kernfs_node recursively |
802 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 803 | * |
324a56e1 | 804 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 805 | */ |
324a56e1 | 806 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 807 | { |
988cd7af TH |
808 | mutex_lock(&kernfs_mutex); |
809 | __kernfs_remove(kn); | |
810 | mutex_unlock(&kernfs_mutex); | |
fd7b9f7b TH |
811 | } |
812 | ||
813 | /** | |
324a56e1 TH |
814 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
815 | * @parent: parent of the target | |
816 | * @name: name of the kernfs_node to remove | |
817 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 818 | * |
324a56e1 TH |
819 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
820 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 821 | */ |
324a56e1 | 822 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
823 | const void *ns) |
824 | { | |
324a56e1 | 825 | struct kernfs_node *kn; |
fd7b9f7b | 826 | |
324a56e1 | 827 | if (!parent) { |
c637b8ac | 828 | WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n", |
fd7b9f7b TH |
829 | name); |
830 | return -ENOENT; | |
831 | } | |
832 | ||
988cd7af | 833 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 834 | |
324a56e1 TH |
835 | kn = kernfs_find_ns(parent, name, ns); |
836 | if (kn) | |
988cd7af | 837 | __kernfs_remove(kn); |
fd7b9f7b | 838 | |
988cd7af | 839 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 840 | |
324a56e1 | 841 | if (kn) |
fd7b9f7b TH |
842 | return 0; |
843 | else | |
844 | return -ENOENT; | |
845 | } | |
846 | ||
847 | /** | |
848 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 849 | * @kn: target node |
fd7b9f7b TH |
850 | * @new_parent: new parent to put @sd under |
851 | * @new_name: new name | |
852 | * @new_ns: new namespace tag | |
853 | */ | |
324a56e1 | 854 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
855 | const char *new_name, const void *new_ns) |
856 | { | |
857 | int error; | |
858 | ||
798c75a0 GKH |
859 | mutex_lock(&kernfs_mutex); |
860 | ||
d0ae3d43 | 861 | error = -ENOENT; |
798c75a0 | 862 | if ((kn->flags | new_parent->flags) & KERNFS_REMOVED) |
d0ae3d43 TH |
863 | goto out; |
864 | ||
fd7b9f7b | 865 | error = 0; |
adc5e8b5 TH |
866 | if ((kn->parent == new_parent) && (kn->ns == new_ns) && |
867 | (strcmp(kn->name, new_name) == 0)) | |
798c75a0 | 868 | goto out; /* nothing to rename */ |
fd7b9f7b TH |
869 | |
870 | error = -EEXIST; | |
871 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
798c75a0 | 872 | goto out; |
fd7b9f7b | 873 | |
324a56e1 | 874 | /* rename kernfs_node */ |
adc5e8b5 | 875 | if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b TH |
876 | error = -ENOMEM; |
877 | new_name = kstrdup(new_name, GFP_KERNEL); | |
878 | if (!new_name) | |
798c75a0 | 879 | goto out; |
fd7b9f7b | 880 | |
47a52e91 TH |
881 | if (kn->flags & KERNFS_STATIC_NAME) |
882 | kn->flags &= ~KERNFS_STATIC_NAME; | |
883 | else | |
884 | kfree(kn->name); | |
885 | ||
adc5e8b5 | 886 | kn->name = new_name; |
fd7b9f7b TH |
887 | } |
888 | ||
889 | /* | |
890 | * Move to the appropriate place in the appropriate directories rbtree. | |
891 | */ | |
c637b8ac | 892 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 893 | kernfs_get(new_parent); |
adc5e8b5 TH |
894 | kernfs_put(kn->parent); |
895 | kn->ns = new_ns; | |
c637b8ac | 896 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 897 | kn->parent = new_parent; |
c637b8ac | 898 | kernfs_link_sibling(kn); |
fd7b9f7b TH |
899 | |
900 | error = 0; | |
798c75a0 | 901 | out: |
a797bfc3 | 902 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
903 | return error; |
904 | } | |
905 | ||
fd7b9f7b | 906 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 907 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 908 | { |
adc5e8b5 | 909 | return (kn->mode >> 12) & 15; |
fd7b9f7b TH |
910 | } |
911 | ||
c637b8ac | 912 | static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b TH |
913 | { |
914 | kernfs_put(filp->private_data); | |
915 | return 0; | |
916 | } | |
917 | ||
c637b8ac | 918 | static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e1 | 919 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b TH |
920 | { |
921 | if (pos) { | |
798c75a0 GKH |
922 | int valid = !(pos->flags & KERNFS_REMOVED) && |
923 | pos->parent == parent && hash == pos->hash; | |
fd7b9f7b TH |
924 | kernfs_put(pos); |
925 | if (!valid) | |
926 | pos = NULL; | |
927 | } | |
928 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
adc5e8b5 | 929 | struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b | 930 | while (node) { |
324a56e1 | 931 | pos = rb_to_kn(node); |
fd7b9f7b | 932 | |
adc5e8b5 | 933 | if (hash < pos->hash) |
fd7b9f7b | 934 | node = node->rb_left; |
adc5e8b5 | 935 | else if (hash > pos->hash) |
fd7b9f7b TH |
936 | node = node->rb_right; |
937 | else | |
938 | break; | |
939 | } | |
940 | } | |
941 | /* Skip over entries in the wrong namespace */ | |
adc5e8b5 TH |
942 | while (pos && pos->ns != ns) { |
943 | struct rb_node *node = rb_next(&pos->rb); | |
fd7b9f7b TH |
944 | if (!node) |
945 | pos = NULL; | |
946 | else | |
324a56e1 | 947 | pos = rb_to_kn(node); |
fd7b9f7b TH |
948 | } |
949 | return pos; | |
950 | } | |
951 | ||
c637b8ac | 952 | static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e1 | 953 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b | 954 | { |
c637b8ac | 955 | pos = kernfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
956 | if (pos) |
957 | do { | |
adc5e8b5 | 958 | struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b TH |
959 | if (!node) |
960 | pos = NULL; | |
961 | else | |
324a56e1 | 962 | pos = rb_to_kn(node); |
adc5e8b5 | 963 | } while (pos && pos->ns != ns); |
fd7b9f7b TH |
964 | return pos; |
965 | } | |
966 | ||
c637b8ac | 967 | static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b TH |
968 | { |
969 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
970 | struct kernfs_node *parent = dentry->d_fsdata; |
971 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
972 | const void *ns = NULL; |
973 | ||
974 | if (!dir_emit_dots(file, ctx)) | |
975 | return 0; | |
a797bfc3 | 976 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 977 | |
324a56e1 | 978 | if (kernfs_ns_enabled(parent)) |
c525aadd | 979 | ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b | 980 | |
c637b8ac | 981 | for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 982 | pos; |
c637b8ac | 983 | pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b5 | 984 | const char *name = pos->name; |
fd7b9f7b TH |
985 | unsigned int type = dt_type(pos); |
986 | int len = strlen(name); | |
adc5e8b5 | 987 | ino_t ino = pos->ino; |
fd7b9f7b | 988 | |
adc5e8b5 | 989 | ctx->pos = pos->hash; |
fd7b9f7b TH |
990 | file->private_data = pos; |
991 | kernfs_get(pos); | |
992 | ||
a797bfc3 | 993 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
994 | if (!dir_emit(ctx, name, len, ino, type)) |
995 | return 0; | |
a797bfc3 | 996 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 997 | } |
a797bfc3 | 998 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
999 | file->private_data = NULL; |
1000 | ctx->pos = INT_MAX; | |
1001 | return 0; | |
1002 | } | |
1003 | ||
c637b8ac TH |
1004 | static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset, |
1005 | int whence) | |
fd7b9f7b TH |
1006 | { |
1007 | struct inode *inode = file_inode(file); | |
1008 | loff_t ret; | |
1009 | ||
1010 | mutex_lock(&inode->i_mutex); | |
1011 | ret = generic_file_llseek(file, offset, whence); | |
1012 | mutex_unlock(&inode->i_mutex); | |
1013 | ||
1014 | return ret; | |
1015 | } | |
1016 | ||
a797bfc3 | 1017 | const struct file_operations kernfs_dir_fops = { |
fd7b9f7b | 1018 | .read = generic_read_dir, |
c637b8ac TH |
1019 | .iterate = kernfs_fop_readdir, |
1020 | .release = kernfs_dir_fop_release, | |
1021 | .llseek = kernfs_dir_fop_llseek, | |
fd7b9f7b | 1022 | }; |