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 | * |
35beab06 TH |
180 | * Deny new active references and drain existing ones. Mutiple |
181 | * removers may invoke this function concurrently on @kn and all will | |
182 | * return after deactivation and draining are complete. | |
fd7b9f7b | 183 | */ |
798c75a0 | 184 | static void kernfs_deactivate(struct kernfs_node *kn) |
35beab06 | 185 | __releases(&kernfs_mutex) __acquires(&kernfs_mutex) |
fd7b9f7b | 186 | { |
abd54f02 | 187 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b | 188 | |
35beab06 | 189 | lockdep_assert_held(&kernfs_mutex); |
798c75a0 GKH |
190 | BUG_ON(!(kn->flags & KERNFS_REMOVED)); |
191 | ||
0890147f GKH |
192 | if (!(kernfs_type(kn) & KERNFS_ACTIVE_REF)) |
193 | return; | |
194 | ||
35beab06 TH |
195 | /* only the first invocation on @kn should deactivate it */ |
196 | if (atomic_read(&kn->active) >= 0) | |
197 | atomic_add(KN_DEACTIVATED_BIAS, &kn->active); | |
ea1c472d | 198 | |
35beab06 | 199 | mutex_unlock(&kernfs_mutex); |
abd54f02 | 200 | |
35beab06 TH |
201 | if (kn->flags & KERNFS_LOCKDEP) { |
202 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); | |
203 | if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS) | |
204 | lock_contended(&kn->dep_map, _RET_IP_); | |
205 | } | |
abd54f02 | 206 | |
35beab06 | 207 | /* but everyone should wait for draining */ |
abd54f02 TH |
208 | wait_event(root->deactivate_waitq, |
209 | atomic_read(&kn->active) == KN_DEACTIVATED_BIAS); | |
fd7b9f7b | 210 | |
a6607930 TH |
211 | if (kn->flags & KERNFS_LOCKDEP) { |
212 | lock_acquired(&kn->dep_map, _RET_IP_); | |
213 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
214 | } | |
35beab06 TH |
215 | |
216 | mutex_lock(&kernfs_mutex); | |
fd7b9f7b TH |
217 | } |
218 | ||
fd7b9f7b | 219 | /** |
324a56e1 TH |
220 | * kernfs_get - get a reference count on a kernfs_node |
221 | * @kn: the target kernfs_node | |
fd7b9f7b | 222 | */ |
324a56e1 | 223 | void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b | 224 | { |
324a56e1 | 225 | if (kn) { |
adc5e8b5 TH |
226 | WARN_ON(!atomic_read(&kn->count)); |
227 | atomic_inc(&kn->count); | |
fd7b9f7b TH |
228 | } |
229 | } | |
230 | EXPORT_SYMBOL_GPL(kernfs_get); | |
231 | ||
232 | /** | |
324a56e1 TH |
233 | * kernfs_put - put a reference count on a kernfs_node |
234 | * @kn: the target kernfs_node | |
fd7b9f7b | 235 | * |
324a56e1 | 236 | * Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b | 237 | */ |
324a56e1 | 238 | void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b | 239 | { |
324a56e1 | 240 | struct kernfs_node *parent; |
ba7443bc | 241 | struct kernfs_root *root; |
fd7b9f7b | 242 | |
adc5e8b5 | 243 | if (!kn || !atomic_dec_and_test(&kn->count)) |
fd7b9f7b | 244 | return; |
324a56e1 | 245 | root = kernfs_root(kn); |
fd7b9f7b | 246 | repeat: |
798c75a0 | 247 | /* Moving/renaming is always done while holding reference. |
adc5e8b5 | 248 | * kn->parent won't change beneath us. |
fd7b9f7b | 249 | */ |
adc5e8b5 | 250 | parent = kn->parent; |
fd7b9f7b | 251 | |
798c75a0 GKH |
252 | WARN(!(kn->flags & KERNFS_REMOVED), "kernfs: free using entry: %s/%s\n", |
253 | parent ? parent->name : "", kn->name); | |
324a56e1 | 254 | |
df23fc39 | 255 | if (kernfs_type(kn) == KERNFS_LINK) |
adc5e8b5 | 256 | kernfs_put(kn->symlink.target_kn); |
2063d608 | 257 | if (!(kn->flags & KERNFS_STATIC_NAME)) |
adc5e8b5 TH |
258 | kfree(kn->name); |
259 | if (kn->iattr) { | |
260 | if (kn->iattr->ia_secdata) | |
261 | security_release_secctx(kn->iattr->ia_secdata, | |
262 | kn->iattr->ia_secdata_len); | |
263 | simple_xattrs_free(&kn->iattr->xattrs); | |
2322392b | 264 | } |
adc5e8b5 TH |
265 | kfree(kn->iattr); |
266 | ida_simple_remove(&root->ino_ida, kn->ino); | |
a797bfc3 | 267 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b | 268 | |
324a56e1 TH |
269 | kn = parent; |
270 | if (kn) { | |
adc5e8b5 | 271 | if (atomic_dec_and_test(&kn->count)) |
ba7443bc TH |
272 | goto repeat; |
273 | } else { | |
324a56e1 | 274 | /* just released the root kn, free @root too */ |
bc755553 | 275 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
276 | kfree(root); |
277 | } | |
fd7b9f7b TH |
278 | } |
279 | EXPORT_SYMBOL_GPL(kernfs_put); | |
280 | ||
c637b8ac | 281 | static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags) |
fd7b9f7b | 282 | { |
324a56e1 | 283 | struct kernfs_node *kn; |
fd7b9f7b TH |
284 | |
285 | if (flags & LOOKUP_RCU) | |
286 | return -ECHILD; | |
287 | ||
19bbb926 TH |
288 | /* Always perform fresh lookup for negatives */ |
289 | if (!dentry->d_inode) | |
290 | goto out_bad_unlocked; | |
291 | ||
324a56e1 | 292 | kn = dentry->d_fsdata; |
a797bfc3 | 293 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 294 | |
798c75a0 GKH |
295 | /* The kernfs node has been deleted */ |
296 | if (kn->flags & KERNFS_REMOVED) | |
fd7b9f7b TH |
297 | goto out_bad; |
298 | ||
c637b8ac | 299 | /* The kernfs node has been moved? */ |
adc5e8b5 | 300 | if (dentry->d_parent->d_fsdata != kn->parent) |
fd7b9f7b TH |
301 | goto out_bad; |
302 | ||
c637b8ac | 303 | /* The kernfs node has been renamed */ |
adc5e8b5 | 304 | if (strcmp(dentry->d_name.name, kn->name) != 0) |
fd7b9f7b TH |
305 | goto out_bad; |
306 | ||
c637b8ac | 307 | /* The kernfs node has been moved to a different namespace */ |
adc5e8b5 | 308 | if (kn->parent && kernfs_ns_enabled(kn->parent) && |
c525aadd | 309 | kernfs_info(dentry->d_sb)->ns != kn->ns) |
fd7b9f7b TH |
310 | goto out_bad; |
311 | ||
a797bfc3 | 312 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
313 | out_valid: |
314 | return 1; | |
315 | out_bad: | |
a797bfc3 | 316 | mutex_unlock(&kernfs_mutex); |
19bbb926 TH |
317 | out_bad_unlocked: |
318 | /* | |
319 | * @dentry doesn't match the underlying kernfs node, drop the | |
320 | * dentry and force lookup. If we have submounts we must allow the | |
321 | * vfs caches to lie about the state of the filesystem to prevent | |
322 | * leaks and other nasty things, so use check_submounts_and_drop() | |
323 | * instead of d_drop(). | |
fd7b9f7b TH |
324 | */ |
325 | if (check_submounts_and_drop(dentry) != 0) | |
326 | goto out_valid; | |
327 | ||
328 | return 0; | |
329 | } | |
330 | ||
c637b8ac | 331 | static void kernfs_dop_release(struct dentry *dentry) |
fd7b9f7b TH |
332 | { |
333 | kernfs_put(dentry->d_fsdata); | |
334 | } | |
335 | ||
a797bfc3 | 336 | const struct dentry_operations kernfs_dops = { |
c637b8ac | 337 | .d_revalidate = kernfs_dop_revalidate, |
c637b8ac | 338 | .d_release = kernfs_dop_release, |
fd7b9f7b TH |
339 | }; |
340 | ||
db4aad20 TH |
341 | static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, |
342 | const char *name, umode_t mode, | |
343 | unsigned flags) | |
fd7b9f7b TH |
344 | { |
345 | char *dup_name = NULL; | |
324a56e1 | 346 | struct kernfs_node *kn; |
bc755553 | 347 | int ret; |
fd7b9f7b | 348 | |
2063d608 | 349 | if (!(flags & KERNFS_STATIC_NAME)) { |
fd7b9f7b TH |
350 | name = dup_name = kstrdup(name, GFP_KERNEL); |
351 | if (!name) | |
352 | return NULL; | |
353 | } | |
354 | ||
a797bfc3 | 355 | kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e1 | 356 | if (!kn) |
fd7b9f7b TH |
357 | goto err_out1; |
358 | ||
bc755553 TH |
359 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
360 | if (ret < 0) | |
fd7b9f7b | 361 | goto err_out2; |
adc5e8b5 | 362 | kn->ino = ret; |
fd7b9f7b | 363 | |
adc5e8b5 | 364 | atomic_set(&kn->count, 1); |
798c75a0 | 365 | atomic_set(&kn->active, 0); |
35beab06 | 366 | RB_CLEAR_NODE(&kn->rb); |
fd7b9f7b | 367 | |
adc5e8b5 TH |
368 | kn->name = name; |
369 | kn->mode = mode; | |
798c75a0 | 370 | kn->flags = flags | KERNFS_REMOVED; |
fd7b9f7b | 371 | |
324a56e1 | 372 | return kn; |
fd7b9f7b TH |
373 | |
374 | err_out2: | |
a797bfc3 | 375 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b TH |
376 | err_out1: |
377 | kfree(dup_name); | |
378 | return NULL; | |
379 | } | |
380 | ||
db4aad20 TH |
381 | struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, |
382 | const char *name, umode_t mode, | |
383 | unsigned flags) | |
384 | { | |
385 | struct kernfs_node *kn; | |
386 | ||
387 | kn = __kernfs_new_node(kernfs_root(parent), name, mode, flags); | |
388 | if (kn) { | |
389 | kernfs_get(parent); | |
390 | kn->parent = parent; | |
391 | } | |
392 | return kn; | |
393 | } | |
394 | ||
7653fe9d GKH |
395 | /** |
396 | * kernfs_addrm_start - prepare for kernfs_node add/remove | |
397 | * @acxt: pointer to kernfs_addrm_cxt to be used | |
398 | * | |
399 | * This function is called when the caller is about to add or remove | |
400 | * kernfs_node. This function acquires kernfs_mutex. @acxt is used | |
401 | * to keep and pass context to other addrm functions. | |
402 | * | |
403 | * LOCKING: | |
404 | * Kernel thread context (may sleep). kernfs_mutex is locked on | |
405 | * return. | |
406 | */ | |
407 | void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt) | |
408 | __acquires(kernfs_mutex) | |
409 | { | |
410 | memset(acxt, 0, sizeof(*acxt)); | |
411 | ||
412 | mutex_lock(&kernfs_mutex); | |
413 | } | |
414 | ||
fd7b9f7b | 415 | /** |
c637b8ac | 416 | * kernfs_add_one - add kernfs_node to parent without warning |
7653fe9d | 417 | * @acxt: addrm context to use |
324a56e1 | 418 | * @kn: kernfs_node to be added |
fd7b9f7b | 419 | * |
db4aad20 TH |
420 | * The caller must already have initialized @kn->parent. This |
421 | * function increments nlink of the parent's inode if @kn is a | |
422 | * directory and link into the children list of the parent. | |
fd7b9f7b | 423 | * |
7653fe9d GKH |
424 | * This function should be called between calls to |
425 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be passed | |
426 | * the same @acxt as passed to kernfs_addrm_start(). | |
427 | * | |
428 | * LOCKING: | |
429 | * Determined by kernfs_addrm_start(). | |
430 | * | |
fd7b9f7b TH |
431 | * RETURNS: |
432 | * 0 on success, -EEXIST if entry with the given name already | |
433 | * exists. | |
434 | */ | |
db4aad20 | 435 | int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn) |
fd7b9f7b | 436 | { |
db4aad20 | 437 | struct kernfs_node *parent = kn->parent; |
7653fe9d | 438 | bool has_ns = kernfs_ns_enabled(parent); |
c525aadd | 439 | struct kernfs_iattrs *ps_iattr; |
fd7b9f7b TH |
440 | int ret; |
441 | ||
7653fe9d GKH |
442 | if (has_ns != (bool)kn->ns) { |
443 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", | |
444 | has_ns ? "required" : "invalid", parent->name, kn->name); | |
445 | return -EINVAL; | |
446 | } | |
fd7b9f7b | 447 | |
df23fc39 | 448 | if (kernfs_type(parent) != KERNFS_DIR) |
7653fe9d | 449 | return -EINVAL; |
fd7b9f7b | 450 | |
798c75a0 GKH |
451 | if (parent->flags & KERNFS_REMOVED) |
452 | return -ENOENT; | |
453 | ||
c637b8ac | 454 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
fd7b9f7b | 455 | |
c637b8ac | 456 | ret = kernfs_link_sibling(kn); |
fd7b9f7b | 457 | if (ret) |
7653fe9d | 458 | return ret; |
fd7b9f7b TH |
459 | |
460 | /* Update timestamps on the parent */ | |
adc5e8b5 | 461 | ps_iattr = parent->iattr; |
fd7b9f7b TH |
462 | if (ps_iattr) { |
463 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
464 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
465 | } | |
466 | ||
467 | /* Mark the entry added into directory tree */ | |
798c75a0 GKH |
468 | kn->flags &= ~KERNFS_REMOVED; |
469 | ||
7653fe9d GKH |
470 | return 0; |
471 | } | |
472 | ||
473 | /** | |
474 | * kernfs_addrm_finish - finish up kernfs_node add/remove | |
475 | * @acxt: addrm context to finish up | |
476 | * | |
477 | * Finish up kernfs_node add/remove. Resources acquired by | |
478 | * kernfs_addrm_start() are released and removed kernfs_nodes are | |
479 | * cleaned up. | |
480 | * | |
481 | * LOCKING: | |
482 | * kernfs_mutex is released. | |
483 | */ | |
484 | void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt) | |
485 | __releases(kernfs_mutex) | |
486 | { | |
487 | /* release resources acquired by kernfs_addrm_start() */ | |
a797bfc3 | 488 | mutex_unlock(&kernfs_mutex); |
7653fe9d GKH |
489 | |
490 | /* kill removed kernfs_nodes */ | |
491 | while (acxt->removed) { | |
492 | struct kernfs_node *kn = acxt->removed; | |
493 | ||
494 | acxt->removed = kn->u.removed_list; | |
495 | ||
55f6e30d | 496 | kernfs_unmap_bin_file(kn); |
7653fe9d GKH |
497 | kernfs_put(kn); |
498 | } | |
fd7b9f7b TH |
499 | } |
500 | ||
501 | /** | |
324a56e1 TH |
502 | * kernfs_find_ns - find kernfs_node with the given name |
503 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
504 | * @name: name to look for |
505 | * @ns: the namespace tag to use | |
506 | * | |
324a56e1 TH |
507 | * Look for kernfs_node with name @name under @parent. Returns pointer to |
508 | * the found kernfs_node on success, %NULL on failure. | |
fd7b9f7b | 509 | */ |
324a56e1 TH |
510 | static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, |
511 | const unsigned char *name, | |
512 | const void *ns) | |
fd7b9f7b | 513 | { |
adc5e8b5 | 514 | struct rb_node *node = parent->dir.children.rb_node; |
ac9bba03 | 515 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
516 | unsigned int hash; |
517 | ||
a797bfc3 | 518 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
519 | |
520 | if (has_ns != (bool)ns) { | |
c637b8ac | 521 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", |
adc5e8b5 | 522 | has_ns ? "required" : "invalid", parent->name, name); |
fd7b9f7b TH |
523 | return NULL; |
524 | } | |
525 | ||
c637b8ac | 526 | hash = kernfs_name_hash(name, ns); |
fd7b9f7b | 527 | while (node) { |
324a56e1 | 528 | struct kernfs_node *kn; |
fd7b9f7b TH |
529 | int result; |
530 | ||
324a56e1 | 531 | kn = rb_to_kn(node); |
c637b8ac | 532 | result = kernfs_name_compare(hash, name, ns, kn); |
fd7b9f7b TH |
533 | if (result < 0) |
534 | node = node->rb_left; | |
535 | else if (result > 0) | |
536 | node = node->rb_right; | |
537 | else | |
324a56e1 | 538 | return kn; |
fd7b9f7b TH |
539 | } |
540 | return NULL; | |
541 | } | |
542 | ||
543 | /** | |
324a56e1 TH |
544 | * kernfs_find_and_get_ns - find and get kernfs_node with the given name |
545 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
546 | * @name: name to look for |
547 | * @ns: the namespace tag to use | |
548 | * | |
324a56e1 | 549 | * Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b | 550 | * if found. This function may sleep and returns pointer to the found |
324a56e1 | 551 | * kernfs_node on success, %NULL on failure. |
fd7b9f7b | 552 | */ |
324a56e1 TH |
553 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
554 | const char *name, const void *ns) | |
fd7b9f7b | 555 | { |
324a56e1 | 556 | struct kernfs_node *kn; |
fd7b9f7b | 557 | |
a797bfc3 | 558 | mutex_lock(&kernfs_mutex); |
324a56e1 TH |
559 | kn = kernfs_find_ns(parent, name, ns); |
560 | kernfs_get(kn); | |
a797bfc3 | 561 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 562 | |
324a56e1 | 563 | return kn; |
fd7b9f7b TH |
564 | } |
565 | EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); | |
566 | ||
ba7443bc TH |
567 | /** |
568 | * kernfs_create_root - create a new kernfs hierarchy | |
80b9bbef | 569 | * @kdops: optional directory syscall operations for the hierarchy |
ba7443bc TH |
570 | * @priv: opaque data associated with the new directory |
571 | * | |
572 | * Returns the root of the new hierarchy on success, ERR_PTR() value on | |
573 | * failure. | |
574 | */ | |
80b9bbef | 575 | struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv) |
ba7443bc TH |
576 | { |
577 | struct kernfs_root *root; | |
324a56e1 | 578 | struct kernfs_node *kn; |
ba7443bc TH |
579 | |
580 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
581 | if (!root) | |
582 | return ERR_PTR(-ENOMEM); | |
583 | ||
bc755553 TH |
584 | ida_init(&root->ino_ida); |
585 | ||
db4aad20 TH |
586 | kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, |
587 | KERNFS_DIR); | |
324a56e1 | 588 | if (!kn) { |
bc755553 | 589 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
590 | kfree(root); |
591 | return ERR_PTR(-ENOMEM); | |
592 | } | |
593 | ||
798c75a0 | 594 | kn->flags &= ~KERNFS_REMOVED; |
324a56e1 | 595 | kn->priv = priv; |
adc5e8b5 | 596 | kn->dir.root = root; |
ba7443bc | 597 | |
80b9bbef | 598 | root->dir_ops = kdops; |
324a56e1 | 599 | root->kn = kn; |
abd54f02 | 600 | init_waitqueue_head(&root->deactivate_waitq); |
ba7443bc TH |
601 | |
602 | return root; | |
603 | } | |
604 | ||
605 | /** | |
606 | * kernfs_destroy_root - destroy a kernfs hierarchy | |
607 | * @root: root of the hierarchy to destroy | |
608 | * | |
609 | * Destroy the hierarchy anchored at @root by removing all existing | |
610 | * directories and destroying @root. | |
611 | */ | |
612 | void kernfs_destroy_root(struct kernfs_root *root) | |
613 | { | |
324a56e1 | 614 | kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc TH |
615 | } |
616 | ||
fd7b9f7b TH |
617 | /** |
618 | * kernfs_create_dir_ns - create a directory | |
619 | * @parent: parent in which to create a new directory | |
620 | * @name: name of the new directory | |
bb8b9d09 | 621 | * @mode: mode of the new directory |
fd7b9f7b TH |
622 | * @priv: opaque data associated with the new directory |
623 | * @ns: optional namespace tag of the directory | |
624 | * | |
625 | * Returns the created node on success, ERR_PTR() value on failure. | |
626 | */ | |
324a56e1 | 627 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d09 TH |
628 | const char *name, umode_t mode, |
629 | void *priv, const void *ns) | |
fd7b9f7b | 630 | { |
7653fe9d | 631 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 632 | struct kernfs_node *kn; |
fd7b9f7b TH |
633 | int rc; |
634 | ||
635 | /* allocate */ | |
db4aad20 | 636 | kn = kernfs_new_node(parent, name, mode | S_IFDIR, KERNFS_DIR); |
324a56e1 | 637 | if (!kn) |
fd7b9f7b TH |
638 | return ERR_PTR(-ENOMEM); |
639 | ||
adc5e8b5 TH |
640 | kn->dir.root = parent->dir.root; |
641 | kn->ns = ns; | |
324a56e1 | 642 | kn->priv = priv; |
fd7b9f7b TH |
643 | |
644 | /* link in */ | |
798c75a0 | 645 | kernfs_addrm_start(&acxt); |
db4aad20 | 646 | rc = kernfs_add_one(&acxt, kn); |
798c75a0 | 647 | kernfs_addrm_finish(&acxt); |
7653fe9d | 648 | |
fd7b9f7b | 649 | if (!rc) |
324a56e1 | 650 | return kn; |
fd7b9f7b | 651 | |
324a56e1 | 652 | kernfs_put(kn); |
fd7b9f7b TH |
653 | return ERR_PTR(rc); |
654 | } | |
655 | ||
c637b8ac TH |
656 | static struct dentry *kernfs_iop_lookup(struct inode *dir, |
657 | struct dentry *dentry, | |
658 | unsigned int flags) | |
fd7b9f7b | 659 | { |
19bbb926 | 660 | struct dentry *ret; |
324a56e1 TH |
661 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
662 | struct kernfs_node *kn; | |
fd7b9f7b TH |
663 | struct inode *inode; |
664 | const void *ns = NULL; | |
665 | ||
a797bfc3 | 666 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 667 | |
324a56e1 | 668 | if (kernfs_ns_enabled(parent)) |
c525aadd | 669 | ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b | 670 | |
324a56e1 | 671 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
672 | |
673 | /* no such entry */ | |
324a56e1 | 674 | if (!kn) { |
19bbb926 | 675 | ret = NULL; |
fd7b9f7b TH |
676 | goto out_unlock; |
677 | } | |
324a56e1 TH |
678 | kernfs_get(kn); |
679 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
680 | |
681 | /* attach dentry and inode */ | |
c637b8ac | 682 | inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
683 | if (!inode) { |
684 | ret = ERR_PTR(-ENOMEM); | |
685 | goto out_unlock; | |
686 | } | |
687 | ||
688 | /* instantiate and hash dentry */ | |
689 | ret = d_materialise_unique(dentry, inode); | |
690 | out_unlock: | |
a797bfc3 | 691 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
692 | return ret; |
693 | } | |
694 | ||
80b9bbef TH |
695 | static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, |
696 | umode_t mode) | |
697 | { | |
698 | struct kernfs_node *parent = dir->i_private; | |
699 | struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops; | |
700 | ||
701 | if (!kdops || !kdops->mkdir) | |
702 | return -EPERM; | |
703 | ||
704 | return kdops->mkdir(parent, dentry->d_name.name, mode); | |
705 | } | |
706 | ||
707 | static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) | |
708 | { | |
709 | struct kernfs_node *kn = dentry->d_fsdata; | |
710 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
711 | ||
712 | if (!kdops || !kdops->rmdir) | |
713 | return -EPERM; | |
714 | ||
715 | return kdops->rmdir(kn); | |
716 | } | |
717 | ||
718 | static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, | |
719 | struct inode *new_dir, struct dentry *new_dentry) | |
720 | { | |
721 | struct kernfs_node *kn = old_dentry->d_fsdata; | |
722 | struct kernfs_node *new_parent = new_dir->i_private; | |
723 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
724 | ||
725 | if (!kdops || !kdops->rename) | |
726 | return -EPERM; | |
727 | ||
728 | return kdops->rename(kn, new_parent, new_dentry->d_name.name); | |
729 | } | |
730 | ||
a797bfc3 | 731 | const struct inode_operations kernfs_dir_iops = { |
c637b8ac TH |
732 | .lookup = kernfs_iop_lookup, |
733 | .permission = kernfs_iop_permission, | |
734 | .setattr = kernfs_iop_setattr, | |
735 | .getattr = kernfs_iop_getattr, | |
736 | .setxattr = kernfs_iop_setxattr, | |
737 | .removexattr = kernfs_iop_removexattr, | |
738 | .getxattr = kernfs_iop_getxattr, | |
739 | .listxattr = kernfs_iop_listxattr, | |
80b9bbef TH |
740 | |
741 | .mkdir = kernfs_iop_mkdir, | |
742 | .rmdir = kernfs_iop_rmdir, | |
743 | .rename = kernfs_iop_rename, | |
fd7b9f7b TH |
744 | }; |
745 | ||
c637b8ac | 746 | static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 747 | { |
324a56e1 | 748 | struct kernfs_node *last; |
fd7b9f7b TH |
749 | |
750 | while (true) { | |
751 | struct rb_node *rbn; | |
752 | ||
753 | last = pos; | |
754 | ||
df23fc39 | 755 | if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b TH |
756 | break; |
757 | ||
adc5e8b5 | 758 | rbn = rb_first(&pos->dir.children); |
fd7b9f7b TH |
759 | if (!rbn) |
760 | break; | |
761 | ||
324a56e1 | 762 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
763 | } |
764 | ||
765 | return last; | |
766 | } | |
767 | ||
768 | /** | |
c637b8ac | 769 | * kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b | 770 | * @pos: the current position (%NULL to initiate traversal) |
324a56e1 | 771 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
772 | * |
773 | * Find the next descendant to visit for post-order traversal of @root's | |
774 | * descendants. @root is included in the iteration and the last node to be | |
775 | * visited. | |
776 | */ | |
c637b8ac TH |
777 | static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, |
778 | struct kernfs_node *root) | |
fd7b9f7b TH |
779 | { |
780 | struct rb_node *rbn; | |
781 | ||
a797bfc3 | 782 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
783 | |
784 | /* if first iteration, visit leftmost descendant which may be root */ | |
785 | if (!pos) | |
c637b8ac | 786 | return kernfs_leftmost_descendant(root); |
fd7b9f7b TH |
787 | |
788 | /* if we visited @root, we're done */ | |
789 | if (pos == root) | |
790 | return NULL; | |
791 | ||
792 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
adc5e8b5 | 793 | rbn = rb_next(&pos->rb); |
fd7b9f7b | 794 | if (rbn) |
c637b8ac | 795 | return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
796 | |
797 | /* no sibling left, visit parent */ | |
adc5e8b5 | 798 | return pos->parent; |
fd7b9f7b TH |
799 | } |
800 | ||
7653fe9d GKH |
801 | static void __kernfs_remove(struct kernfs_addrm_cxt *acxt, |
802 | struct kernfs_node *kn) | |
fd7b9f7b | 803 | { |
35beab06 TH |
804 | struct kernfs_node *pos; |
805 | ||
806 | lockdep_assert_held(&kernfs_mutex); | |
fd7b9f7b | 807 | |
ce9b499c GKH |
808 | if (!kn) |
809 | return; | |
810 | ||
c637b8ac | 811 | pr_debug("kernfs %s: removing\n", kn->name); |
fd7b9f7b | 812 | |
35beab06 TH |
813 | /* disable lookup and node creation under @kn */ |
814 | pos = NULL; | |
815 | while ((pos = kernfs_next_descendant_post(pos, kn))) | |
816 | pos->flags |= KERNFS_REMOVED; | |
817 | ||
818 | /* deactivate and unlink the subtree node-by-node */ | |
fd7b9f7b | 819 | do { |
35beab06 TH |
820 | pos = kernfs_leftmost_descendant(kn); |
821 | ||
822 | /* | |
823 | * kernfs_deactivate() drops kernfs_mutex temporarily and | |
824 | * @pos's base ref could have been put by someone else by | |
825 | * the time the function returns. Make sure it doesn't go | |
826 | * away underneath us. | |
827 | */ | |
828 | kernfs_get(pos); | |
829 | ||
830 | kernfs_deactivate(pos); | |
831 | ||
832 | /* | |
833 | * kernfs_unlink_sibling() succeeds once per node. Use it | |
834 | * to decide who's responsible for cleanups. | |
835 | */ | |
836 | if (!pos->parent || kernfs_unlink_sibling(pos)) { | |
837 | struct kernfs_iattrs *ps_iattr = | |
838 | pos->parent ? pos->parent->iattr : NULL; | |
839 | ||
840 | /* update timestamps on the parent */ | |
841 | if (ps_iattr) { | |
842 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
843 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
844 | } | |
845 | ||
846 | pos->u.removed_list = acxt->removed; | |
847 | acxt->removed = pos; | |
848 | } | |
849 | ||
850 | kernfs_put(pos); | |
851 | } while (pos != kn); | |
fd7b9f7b TH |
852 | } |
853 | ||
854 | /** | |
324a56e1 TH |
855 | * kernfs_remove - remove a kernfs_node recursively |
856 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 857 | * |
324a56e1 | 858 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 859 | */ |
324a56e1 | 860 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 861 | { |
7653fe9d GKH |
862 | struct kernfs_addrm_cxt acxt; |
863 | ||
864 | kernfs_addrm_start(&acxt); | |
865 | __kernfs_remove(&acxt, kn); | |
866 | kernfs_addrm_finish(&acxt); | |
fd7b9f7b TH |
867 | } |
868 | ||
869 | /** | |
324a56e1 TH |
870 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
871 | * @parent: parent of the target | |
872 | * @name: name of the kernfs_node to remove | |
873 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 874 | * |
324a56e1 TH |
875 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
876 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 877 | */ |
324a56e1 | 878 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
879 | const void *ns) |
880 | { | |
7653fe9d | 881 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 882 | struct kernfs_node *kn; |
fd7b9f7b | 883 | |
324a56e1 | 884 | if (!parent) { |
c637b8ac | 885 | WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n", |
fd7b9f7b TH |
886 | name); |
887 | return -ENOENT; | |
888 | } | |
889 | ||
7653fe9d | 890 | kernfs_addrm_start(&acxt); |
fd7b9f7b | 891 | |
324a56e1 TH |
892 | kn = kernfs_find_ns(parent, name, ns); |
893 | if (kn) | |
7653fe9d | 894 | __kernfs_remove(&acxt, kn); |
fd7b9f7b | 895 | |
7653fe9d | 896 | kernfs_addrm_finish(&acxt); |
fd7b9f7b | 897 | |
324a56e1 | 898 | if (kn) |
fd7b9f7b TH |
899 | return 0; |
900 | else | |
901 | return -ENOENT; | |
902 | } | |
903 | ||
904 | /** | |
905 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 906 | * @kn: target node |
fd7b9f7b TH |
907 | * @new_parent: new parent to put @sd under |
908 | * @new_name: new name | |
909 | * @new_ns: new namespace tag | |
910 | */ | |
324a56e1 | 911 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
912 | const char *new_name, const void *new_ns) |
913 | { | |
914 | int error; | |
915 | ||
798c75a0 GKH |
916 | mutex_lock(&kernfs_mutex); |
917 | ||
d0ae3d43 | 918 | error = -ENOENT; |
798c75a0 | 919 | if ((kn->flags | new_parent->flags) & KERNFS_REMOVED) |
d0ae3d43 TH |
920 | goto out; |
921 | ||
fd7b9f7b | 922 | error = 0; |
adc5e8b5 TH |
923 | if ((kn->parent == new_parent) && (kn->ns == new_ns) && |
924 | (strcmp(kn->name, new_name) == 0)) | |
798c75a0 | 925 | goto out; /* nothing to rename */ |
fd7b9f7b TH |
926 | |
927 | error = -EEXIST; | |
928 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
798c75a0 | 929 | goto out; |
fd7b9f7b | 930 | |
324a56e1 | 931 | /* rename kernfs_node */ |
adc5e8b5 | 932 | if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b TH |
933 | error = -ENOMEM; |
934 | new_name = kstrdup(new_name, GFP_KERNEL); | |
935 | if (!new_name) | |
798c75a0 | 936 | goto out; |
fd7b9f7b | 937 | |
47a52e91 TH |
938 | if (kn->flags & KERNFS_STATIC_NAME) |
939 | kn->flags &= ~KERNFS_STATIC_NAME; | |
940 | else | |
941 | kfree(kn->name); | |
942 | ||
adc5e8b5 | 943 | kn->name = new_name; |
fd7b9f7b TH |
944 | } |
945 | ||
946 | /* | |
947 | * Move to the appropriate place in the appropriate directories rbtree. | |
948 | */ | |
c637b8ac | 949 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 950 | kernfs_get(new_parent); |
adc5e8b5 TH |
951 | kernfs_put(kn->parent); |
952 | kn->ns = new_ns; | |
c637b8ac | 953 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 954 | kn->parent = new_parent; |
c637b8ac | 955 | kernfs_link_sibling(kn); |
fd7b9f7b TH |
956 | |
957 | error = 0; | |
798c75a0 | 958 | out: |
a797bfc3 | 959 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
960 | return error; |
961 | } | |
962 | ||
fd7b9f7b | 963 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 964 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 965 | { |
adc5e8b5 | 966 | return (kn->mode >> 12) & 15; |
fd7b9f7b TH |
967 | } |
968 | ||
c637b8ac | 969 | static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b TH |
970 | { |
971 | kernfs_put(filp->private_data); | |
972 | return 0; | |
973 | } | |
974 | ||
c637b8ac | 975 | static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e1 | 976 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b TH |
977 | { |
978 | if (pos) { | |
798c75a0 GKH |
979 | int valid = !(pos->flags & KERNFS_REMOVED) && |
980 | pos->parent == parent && hash == pos->hash; | |
fd7b9f7b TH |
981 | kernfs_put(pos); |
982 | if (!valid) | |
983 | pos = NULL; | |
984 | } | |
985 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
adc5e8b5 | 986 | struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b | 987 | while (node) { |
324a56e1 | 988 | pos = rb_to_kn(node); |
fd7b9f7b | 989 | |
adc5e8b5 | 990 | if (hash < pos->hash) |
fd7b9f7b | 991 | node = node->rb_left; |
adc5e8b5 | 992 | else if (hash > pos->hash) |
fd7b9f7b TH |
993 | node = node->rb_right; |
994 | else | |
995 | break; | |
996 | } | |
997 | } | |
998 | /* Skip over entries in the wrong namespace */ | |
adc5e8b5 TH |
999 | while (pos && pos->ns != ns) { |
1000 | struct rb_node *node = rb_next(&pos->rb); | |
fd7b9f7b TH |
1001 | if (!node) |
1002 | pos = NULL; | |
1003 | else | |
324a56e1 | 1004 | pos = rb_to_kn(node); |
fd7b9f7b TH |
1005 | } |
1006 | return pos; | |
1007 | } | |
1008 | ||
c637b8ac | 1009 | static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e1 | 1010 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b | 1011 | { |
c637b8ac | 1012 | pos = kernfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
1013 | if (pos) |
1014 | do { | |
adc5e8b5 | 1015 | struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b TH |
1016 | if (!node) |
1017 | pos = NULL; | |
1018 | else | |
324a56e1 | 1019 | pos = rb_to_kn(node); |
adc5e8b5 | 1020 | } while (pos && pos->ns != ns); |
fd7b9f7b TH |
1021 | return pos; |
1022 | } | |
1023 | ||
c637b8ac | 1024 | static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b TH |
1025 | { |
1026 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
1027 | struct kernfs_node *parent = dentry->d_fsdata; |
1028 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
1029 | const void *ns = NULL; |
1030 | ||
1031 | if (!dir_emit_dots(file, ctx)) | |
1032 | return 0; | |
a797bfc3 | 1033 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1034 | |
324a56e1 | 1035 | if (kernfs_ns_enabled(parent)) |
c525aadd | 1036 | ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b | 1037 | |
c637b8ac | 1038 | for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 1039 | pos; |
c637b8ac | 1040 | pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b5 | 1041 | const char *name = pos->name; |
fd7b9f7b TH |
1042 | unsigned int type = dt_type(pos); |
1043 | int len = strlen(name); | |
adc5e8b5 | 1044 | ino_t ino = pos->ino; |
fd7b9f7b | 1045 | |
adc5e8b5 | 1046 | ctx->pos = pos->hash; |
fd7b9f7b TH |
1047 | file->private_data = pos; |
1048 | kernfs_get(pos); | |
1049 | ||
a797bfc3 | 1050 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1051 | if (!dir_emit(ctx, name, len, ino, type)) |
1052 | return 0; | |
a797bfc3 | 1053 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1054 | } |
a797bfc3 | 1055 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1056 | file->private_data = NULL; |
1057 | ctx->pos = INT_MAX; | |
1058 | return 0; | |
1059 | } | |
1060 | ||
c637b8ac TH |
1061 | static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset, |
1062 | int whence) | |
fd7b9f7b TH |
1063 | { |
1064 | struct inode *inode = file_inode(file); | |
1065 | loff_t ret; | |
1066 | ||
1067 | mutex_lock(&inode->i_mutex); | |
1068 | ret = generic_file_llseek(file, offset, whence); | |
1069 | mutex_unlock(&inode->i_mutex); | |
1070 | ||
1071 | return ret; | |
1072 | } | |
1073 | ||
a797bfc3 | 1074 | const struct file_operations kernfs_dir_fops = { |
fd7b9f7b | 1075 | .read = generic_read_dir, |
c637b8ac TH |
1076 | .iterate = kernfs_fop_readdir, |
1077 | .release = kernfs_dir_fop_release, | |
1078 | .llseek = kernfs_dir_fop_llseek, | |
fd7b9f7b | 1079 | }; |