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 | * |
4f4b1b64 | 184 | * Drain existing usages. |
fd7b9f7b | 185 | */ |
4f4b1b64 | 186 | static void kernfs_drain(struct kernfs_node *kn) |
fd7b9f7b | 187 | { |
ea1c472d | 188 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b | 189 | |
ae34372e | 190 | WARN_ON_ONCE(atomic_read(&kn->active) >= 0); |
ea1c472d | 191 | |
a69d001c TH |
192 | if (kernfs_lockdep(kn)) { |
193 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); | |
194 | if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS) | |
195 | lock_contended(&kn->dep_map, _RET_IP_); | |
196 | } | |
ea1c472d TH |
197 | |
198 | wait_event(root->deactivate_waitq, | |
199 | atomic_read(&kn->active) == KN_DEACTIVATED_BIAS); | |
fd7b9f7b | 200 | |
a69d001c TH |
201 | if (kernfs_lockdep(kn)) { |
202 | lock_acquired(&kn->dep_map, _RET_IP_); | |
203 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
204 | } | |
fd7b9f7b TH |
205 | } |
206 | ||
fd7b9f7b | 207 | /** |
324a56e1 TH |
208 | * kernfs_get - get a reference count on a kernfs_node |
209 | * @kn: the target kernfs_node | |
fd7b9f7b | 210 | */ |
324a56e1 | 211 | void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b | 212 | { |
324a56e1 | 213 | if (kn) { |
adc5e8b5 TH |
214 | WARN_ON(!atomic_read(&kn->count)); |
215 | atomic_inc(&kn->count); | |
fd7b9f7b TH |
216 | } |
217 | } | |
218 | EXPORT_SYMBOL_GPL(kernfs_get); | |
219 | ||
220 | /** | |
324a56e1 TH |
221 | * kernfs_put - put a reference count on a kernfs_node |
222 | * @kn: the target kernfs_node | |
fd7b9f7b | 223 | * |
324a56e1 | 224 | * Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b | 225 | */ |
324a56e1 | 226 | void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b | 227 | { |
324a56e1 | 228 | struct kernfs_node *parent; |
ba7443bc | 229 | struct kernfs_root *root; |
fd7b9f7b | 230 | |
adc5e8b5 | 231 | if (!kn || !atomic_dec_and_test(&kn->count)) |
fd7b9f7b | 232 | return; |
324a56e1 | 233 | root = kernfs_root(kn); |
fd7b9f7b | 234 | repeat: |
ae34372e TH |
235 | /* |
236 | * Moving/renaming is always done while holding reference. | |
adc5e8b5 | 237 | * kn->parent won't change beneath us. |
fd7b9f7b | 238 | */ |
adc5e8b5 | 239 | parent = kn->parent; |
fd7b9f7b | 240 | |
ae34372e TH |
241 | WARN_ONCE(atomic_read(&kn->active) != KN_DEACTIVATED_BIAS, |
242 | "kernfs_put: %s/%s: released with incorrect active_ref %d\n", | |
243 | parent ? parent->name : "", kn->name, atomic_read(&kn->active)); | |
324a56e1 | 244 | |
df23fc39 | 245 | if (kernfs_type(kn) == KERNFS_LINK) |
adc5e8b5 | 246 | kernfs_put(kn->symlink.target_kn); |
2063d608 | 247 | if (!(kn->flags & KERNFS_STATIC_NAME)) |
adc5e8b5 TH |
248 | kfree(kn->name); |
249 | if (kn->iattr) { | |
250 | if (kn->iattr->ia_secdata) | |
251 | security_release_secctx(kn->iattr->ia_secdata, | |
252 | kn->iattr->ia_secdata_len); | |
253 | simple_xattrs_free(&kn->iattr->xattrs); | |
2322392b | 254 | } |
adc5e8b5 TH |
255 | kfree(kn->iattr); |
256 | ida_simple_remove(&root->ino_ida, kn->ino); | |
a797bfc3 | 257 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b | 258 | |
324a56e1 TH |
259 | kn = parent; |
260 | if (kn) { | |
adc5e8b5 | 261 | if (atomic_dec_and_test(&kn->count)) |
ba7443bc TH |
262 | goto repeat; |
263 | } else { | |
324a56e1 | 264 | /* just released the root kn, free @root too */ |
bc755553 | 265 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
266 | kfree(root); |
267 | } | |
fd7b9f7b TH |
268 | } |
269 | EXPORT_SYMBOL_GPL(kernfs_put); | |
270 | ||
c637b8ac | 271 | static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags) |
fd7b9f7b | 272 | { |
324a56e1 | 273 | struct kernfs_node *kn; |
fd7b9f7b TH |
274 | |
275 | if (flags & LOOKUP_RCU) | |
276 | return -ECHILD; | |
277 | ||
19bbb926 TH |
278 | /* Always perform fresh lookup for negatives */ |
279 | if (!dentry->d_inode) | |
280 | goto out_bad_unlocked; | |
281 | ||
324a56e1 | 282 | kn = dentry->d_fsdata; |
a797bfc3 | 283 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 284 | |
ae34372e TH |
285 | /* Force fresh lookup if removed */ |
286 | if (kn->parent && RB_EMPTY_NODE(&kn->rb)) | |
fd7b9f7b TH |
287 | goto out_bad; |
288 | ||
c637b8ac | 289 | /* The kernfs node has been moved? */ |
adc5e8b5 | 290 | if (dentry->d_parent->d_fsdata != kn->parent) |
fd7b9f7b TH |
291 | goto out_bad; |
292 | ||
c637b8ac | 293 | /* The kernfs node has been renamed */ |
adc5e8b5 | 294 | if (strcmp(dentry->d_name.name, kn->name) != 0) |
fd7b9f7b TH |
295 | goto out_bad; |
296 | ||
c637b8ac | 297 | /* The kernfs node has been moved to a different namespace */ |
adc5e8b5 | 298 | if (kn->parent && kernfs_ns_enabled(kn->parent) && |
c525aadd | 299 | kernfs_info(dentry->d_sb)->ns != kn->ns) |
fd7b9f7b TH |
300 | goto out_bad; |
301 | ||
a797bfc3 | 302 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
303 | out_valid: |
304 | return 1; | |
305 | out_bad: | |
a797bfc3 | 306 | mutex_unlock(&kernfs_mutex); |
19bbb926 TH |
307 | out_bad_unlocked: |
308 | /* | |
309 | * @dentry doesn't match the underlying kernfs node, drop the | |
310 | * dentry and force lookup. If we have submounts we must allow the | |
311 | * vfs caches to lie about the state of the filesystem to prevent | |
312 | * leaks and other nasty things, so use check_submounts_and_drop() | |
313 | * instead of d_drop(). | |
fd7b9f7b TH |
314 | */ |
315 | if (check_submounts_and_drop(dentry) != 0) | |
316 | goto out_valid; | |
317 | ||
318 | return 0; | |
319 | } | |
320 | ||
c637b8ac | 321 | static void kernfs_dop_release(struct dentry *dentry) |
fd7b9f7b TH |
322 | { |
323 | kernfs_put(dentry->d_fsdata); | |
324 | } | |
325 | ||
a797bfc3 | 326 | const struct dentry_operations kernfs_dops = { |
c637b8ac | 327 | .d_revalidate = kernfs_dop_revalidate, |
c637b8ac | 328 | .d_release = kernfs_dop_release, |
fd7b9f7b TH |
329 | }; |
330 | ||
c637b8ac | 331 | struct kernfs_node *kernfs_new_node(struct kernfs_root *root, const char *name, |
2063d608 | 332 | umode_t mode, unsigned flags) |
fd7b9f7b TH |
333 | { |
334 | char *dup_name = NULL; | |
324a56e1 | 335 | struct kernfs_node *kn; |
bc755553 | 336 | int ret; |
fd7b9f7b | 337 | |
2063d608 | 338 | if (!(flags & KERNFS_STATIC_NAME)) { |
fd7b9f7b TH |
339 | name = dup_name = kstrdup(name, GFP_KERNEL); |
340 | if (!name) | |
341 | return NULL; | |
342 | } | |
343 | ||
a797bfc3 | 344 | kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e1 | 345 | if (!kn) |
fd7b9f7b TH |
346 | goto err_out1; |
347 | ||
bc755553 TH |
348 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
349 | if (ret < 0) | |
fd7b9f7b | 350 | goto err_out2; |
adc5e8b5 | 351 | kn->ino = ret; |
fd7b9f7b | 352 | |
adc5e8b5 | 353 | atomic_set(&kn->count, 1); |
ae34372e TH |
354 | atomic_set(&kn->active, KN_DEACTIVATED_BIAS); |
355 | RB_CLEAR_NODE(&kn->rb); | |
fd7b9f7b | 356 | |
adc5e8b5 TH |
357 | kn->name = name; |
358 | kn->mode = mode; | |
ae34372e | 359 | kn->flags = flags; |
fd7b9f7b | 360 | |
324a56e1 | 361 | return kn; |
fd7b9f7b TH |
362 | |
363 | err_out2: | |
a797bfc3 | 364 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b TH |
365 | err_out1: |
366 | kfree(dup_name); | |
367 | return NULL; | |
368 | } | |
369 | ||
7653fe9d GKH |
370 | /** |
371 | * kernfs_addrm_start - prepare for kernfs_node add/remove | |
372 | * @acxt: pointer to kernfs_addrm_cxt to be used | |
373 | * | |
374 | * This function is called when the caller is about to add or remove | |
375 | * kernfs_node. This function acquires kernfs_mutex. @acxt is used | |
376 | * to keep and pass context to other addrm functions. | |
377 | * | |
378 | * LOCKING: | |
379 | * Kernel thread context (may sleep). kernfs_mutex is locked on | |
380 | * return. | |
381 | */ | |
382 | void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt) | |
383 | __acquires(kernfs_mutex) | |
384 | { | |
385 | memset(acxt, 0, sizeof(*acxt)); | |
386 | ||
387 | mutex_lock(&kernfs_mutex); | |
388 | } | |
389 | ||
fd7b9f7b | 390 | /** |
c637b8ac | 391 | * kernfs_add_one - add kernfs_node to parent without warning |
7653fe9d | 392 | * @acxt: addrm context to use |
324a56e1 TH |
393 | * @kn: kernfs_node to be added |
394 | * @parent: the parent kernfs_node to add @kn to | |
fd7b9f7b | 395 | * |
adc5e8b5 TH |
396 | * Get @parent and set @kn->parent to it and increment nlink of the |
397 | * parent inode if @kn is a directory and link into the children list | |
398 | * of the parent. | |
fd7b9f7b | 399 | * |
7653fe9d GKH |
400 | * This function should be called between calls to |
401 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be passed | |
402 | * the same @acxt as passed to kernfs_addrm_start(). | |
403 | * | |
404 | * LOCKING: | |
405 | * Determined by kernfs_addrm_start(). | |
406 | * | |
fd7b9f7b TH |
407 | * RETURNS: |
408 | * 0 on success, -EEXIST if entry with the given name already | |
409 | * exists. | |
410 | */ | |
7653fe9d GKH |
411 | int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn, |
412 | struct kernfs_node *parent) | |
fd7b9f7b | 413 | { |
7653fe9d | 414 | bool has_ns = kernfs_ns_enabled(parent); |
c525aadd | 415 | struct kernfs_iattrs *ps_iattr; |
fd7b9f7b TH |
416 | int ret; |
417 | ||
7653fe9d | 418 | WARN_ON_ONCE(atomic_read(&parent->active) < 0); |
99177a34 | 419 | |
7653fe9d GKH |
420 | if (has_ns != (bool)kn->ns) { |
421 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", | |
422 | has_ns ? "required" : "invalid", parent->name, kn->name); | |
423 | return -EINVAL; | |
424 | } | |
fd7b9f7b | 425 | |
df23fc39 | 426 | if (kernfs_type(parent) != KERNFS_DIR) |
7653fe9d | 427 | return -EINVAL; |
fd7b9f7b | 428 | |
c637b8ac | 429 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 430 | kn->parent = parent; |
324a56e1 | 431 | kernfs_get(parent); |
fd7b9f7b | 432 | |
c637b8ac | 433 | ret = kernfs_link_sibling(kn); |
fd7b9f7b | 434 | if (ret) |
7653fe9d | 435 | return ret; |
fd7b9f7b TH |
436 | |
437 | /* Update timestamps on the parent */ | |
adc5e8b5 | 438 | ps_iattr = parent->iattr; |
fd7b9f7b TH |
439 | if (ps_iattr) { |
440 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
441 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
442 | } | |
443 | ||
444 | /* Mark the entry added into directory tree */ | |
ae34372e | 445 | atomic_sub(KN_DEACTIVATED_BIAS, &kn->active); |
7653fe9d GKH |
446 | return 0; |
447 | } | |
448 | ||
4f4b1b64 GKH |
449 | /** |
450 | * kernfs_remove_one - remove kernfs_node from parent | |
451 | * @acxt: addrm context to use | |
452 | * @kn: kernfs_node to be removed | |
453 | * | |
454 | * Mark @kn removed and drop nlink of parent inode if @kn is a | |
455 | * directory. @kn is unlinked from the children list. | |
456 | * | |
457 | * This function should be called between calls to | |
458 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be | |
459 | * passed the same @acxt as passed to kernfs_addrm_start(). | |
460 | * | |
461 | * LOCKING: | |
462 | * Determined by kernfs_addrm_start(). | |
463 | */ | |
464 | static void kernfs_remove_one(struct kernfs_addrm_cxt *acxt, | |
465 | struct kernfs_node *kn) | |
466 | { | |
467 | struct kernfs_iattrs *ps_iattr; | |
468 | ||
469 | /* | |
470 | * Removal can be called multiple times on the same node. Only the | |
471 | * first invocation is effective and puts the base ref. | |
472 | */ | |
473 | if (atomic_read(&kn->active) < 0) | |
474 | return; | |
475 | ||
476 | if (kn->parent) { | |
477 | kernfs_unlink_sibling(kn); | |
478 | ||
479 | /* Update timestamps on the parent */ | |
480 | ps_iattr = kn->parent->iattr; | |
481 | if (ps_iattr) { | |
482 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
483 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
484 | } | |
485 | } | |
486 | ||
487 | atomic_add(KN_DEACTIVATED_BIAS, &kn->active); | |
488 | kn->u.removed_list = acxt->removed; | |
489 | acxt->removed = kn; | |
490 | } | |
491 | ||
7653fe9d GKH |
492 | /** |
493 | * kernfs_addrm_finish - finish up kernfs_node add/remove | |
494 | * @acxt: addrm context to finish up | |
495 | * | |
496 | * Finish up kernfs_node add/remove. Resources acquired by | |
497 | * kernfs_addrm_start() are released and removed kernfs_nodes are | |
498 | * cleaned up. | |
499 | * | |
500 | * LOCKING: | |
501 | * kernfs_mutex is released. | |
502 | */ | |
503 | void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt) | |
504 | __releases(kernfs_mutex) | |
505 | { | |
506 | /* release resources acquired by kernfs_addrm_start() */ | |
a797bfc3 | 507 | mutex_unlock(&kernfs_mutex); |
7653fe9d GKH |
508 | |
509 | /* kill removed kernfs_nodes */ | |
510 | while (acxt->removed) { | |
511 | struct kernfs_node *kn = acxt->removed; | |
512 | ||
513 | acxt->removed = kn->u.removed_list; | |
514 | ||
4f4b1b64 | 515 | kernfs_drain(kn); |
55f6e30d | 516 | kernfs_unmap_bin_file(kn); |
7653fe9d GKH |
517 | kernfs_put(kn); |
518 | } | |
fd7b9f7b TH |
519 | } |
520 | ||
521 | /** | |
324a56e1 TH |
522 | * kernfs_find_ns - find kernfs_node with the given name |
523 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
524 | * @name: name to look for |
525 | * @ns: the namespace tag to use | |
526 | * | |
324a56e1 TH |
527 | * Look for kernfs_node with name @name under @parent. Returns pointer to |
528 | * the found kernfs_node on success, %NULL on failure. | |
fd7b9f7b | 529 | */ |
324a56e1 TH |
530 | static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, |
531 | const unsigned char *name, | |
532 | const void *ns) | |
fd7b9f7b | 533 | { |
adc5e8b5 | 534 | struct rb_node *node = parent->dir.children.rb_node; |
ac9bba03 | 535 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
536 | unsigned int hash; |
537 | ||
a797bfc3 | 538 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
539 | |
540 | if (has_ns != (bool)ns) { | |
c637b8ac | 541 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", |
adc5e8b5 | 542 | has_ns ? "required" : "invalid", parent->name, name); |
fd7b9f7b TH |
543 | return NULL; |
544 | } | |
545 | ||
c637b8ac | 546 | hash = kernfs_name_hash(name, ns); |
fd7b9f7b | 547 | while (node) { |
324a56e1 | 548 | struct kernfs_node *kn; |
fd7b9f7b TH |
549 | int result; |
550 | ||
324a56e1 | 551 | kn = rb_to_kn(node); |
c637b8ac | 552 | result = kernfs_name_compare(hash, name, ns, kn); |
fd7b9f7b TH |
553 | if (result < 0) |
554 | node = node->rb_left; | |
555 | else if (result > 0) | |
556 | node = node->rb_right; | |
557 | else | |
324a56e1 | 558 | return kn; |
fd7b9f7b TH |
559 | } |
560 | return NULL; | |
561 | } | |
562 | ||
563 | /** | |
324a56e1 TH |
564 | * kernfs_find_and_get_ns - find and get kernfs_node with the given name |
565 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
566 | * @name: name to look for |
567 | * @ns: the namespace tag to use | |
568 | * | |
324a56e1 | 569 | * Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b | 570 | * if found. This function may sleep and returns pointer to the found |
324a56e1 | 571 | * kernfs_node on success, %NULL on failure. |
fd7b9f7b | 572 | */ |
324a56e1 TH |
573 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
574 | const char *name, const void *ns) | |
fd7b9f7b | 575 | { |
324a56e1 | 576 | struct kernfs_node *kn; |
fd7b9f7b | 577 | |
a797bfc3 | 578 | mutex_lock(&kernfs_mutex); |
324a56e1 TH |
579 | kn = kernfs_find_ns(parent, name, ns); |
580 | kernfs_get(kn); | |
a797bfc3 | 581 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 582 | |
324a56e1 | 583 | return kn; |
fd7b9f7b TH |
584 | } |
585 | EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); | |
586 | ||
ba7443bc TH |
587 | /** |
588 | * kernfs_create_root - create a new kernfs hierarchy | |
80b9bbef | 589 | * @kdops: optional directory syscall operations for the hierarchy |
ba7443bc TH |
590 | * @priv: opaque data associated with the new directory |
591 | * | |
592 | * Returns the root of the new hierarchy on success, ERR_PTR() value on | |
593 | * failure. | |
594 | */ | |
80b9bbef | 595 | struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv) |
ba7443bc TH |
596 | { |
597 | struct kernfs_root *root; | |
324a56e1 | 598 | struct kernfs_node *kn; |
ba7443bc TH |
599 | |
600 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
601 | if (!root) | |
602 | return ERR_PTR(-ENOMEM); | |
603 | ||
bc755553 TH |
604 | ida_init(&root->ino_ida); |
605 | ||
c637b8ac | 606 | kn = kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, KERNFS_DIR); |
324a56e1 | 607 | if (!kn) { |
bc755553 | 608 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
609 | kfree(root); |
610 | return ERR_PTR(-ENOMEM); | |
611 | } | |
612 | ||
ae34372e | 613 | atomic_sub(KN_DEACTIVATED_BIAS, &kn->active); |
324a56e1 | 614 | kn->priv = priv; |
adc5e8b5 | 615 | kn->dir.root = root; |
ba7443bc | 616 | |
80b9bbef | 617 | root->dir_ops = kdops; |
324a56e1 | 618 | root->kn = kn; |
ea1c472d | 619 | init_waitqueue_head(&root->deactivate_waitq); |
ba7443bc TH |
620 | |
621 | return root; | |
622 | } | |
623 | ||
624 | /** | |
625 | * kernfs_destroy_root - destroy a kernfs hierarchy | |
626 | * @root: root of the hierarchy to destroy | |
627 | * | |
628 | * Destroy the hierarchy anchored at @root by removing all existing | |
629 | * directories and destroying @root. | |
630 | */ | |
631 | void kernfs_destroy_root(struct kernfs_root *root) | |
632 | { | |
324a56e1 | 633 | kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc TH |
634 | } |
635 | ||
fd7b9f7b TH |
636 | /** |
637 | * kernfs_create_dir_ns - create a directory | |
638 | * @parent: parent in which to create a new directory | |
639 | * @name: name of the new directory | |
bb8b9d09 | 640 | * @mode: mode of the new directory |
fd7b9f7b TH |
641 | * @priv: opaque data associated with the new directory |
642 | * @ns: optional namespace tag of the directory | |
643 | * | |
644 | * Returns the created node on success, ERR_PTR() value on failure. | |
645 | */ | |
324a56e1 | 646 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d09 TH |
647 | const char *name, umode_t mode, |
648 | void *priv, const void *ns) | |
fd7b9f7b | 649 | { |
7653fe9d | 650 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 651 | struct kernfs_node *kn; |
fd7b9f7b TH |
652 | int rc; |
653 | ||
654 | /* allocate */ | |
bb8b9d09 TH |
655 | kn = kernfs_new_node(kernfs_root(parent), name, mode | S_IFDIR, |
656 | KERNFS_DIR); | |
324a56e1 | 657 | if (!kn) |
fd7b9f7b TH |
658 | return ERR_PTR(-ENOMEM); |
659 | ||
adc5e8b5 TH |
660 | kn->dir.root = parent->dir.root; |
661 | kn->ns = ns; | |
324a56e1 | 662 | kn->priv = priv; |
fd7b9f7b TH |
663 | |
664 | /* link in */ | |
7653fe9d GKH |
665 | rc = -ENOENT; |
666 | if (kernfs_get_active(parent)) { | |
667 | kernfs_addrm_start(&acxt); | |
668 | rc = kernfs_add_one(&acxt, kn, parent); | |
669 | kernfs_addrm_finish(&acxt); | |
670 | kernfs_put_active(parent); | |
671 | } | |
672 | ||
fd7b9f7b | 673 | if (!rc) |
324a56e1 | 674 | return kn; |
fd7b9f7b | 675 | |
324a56e1 | 676 | kernfs_put(kn); |
fd7b9f7b TH |
677 | return ERR_PTR(rc); |
678 | } | |
679 | ||
c637b8ac TH |
680 | static struct dentry *kernfs_iop_lookup(struct inode *dir, |
681 | struct dentry *dentry, | |
682 | unsigned int flags) | |
fd7b9f7b | 683 | { |
19bbb926 | 684 | struct dentry *ret; |
324a56e1 TH |
685 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
686 | struct kernfs_node *kn; | |
fd7b9f7b TH |
687 | struct inode *inode; |
688 | const void *ns = NULL; | |
689 | ||
a797bfc3 | 690 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 691 | |
324a56e1 | 692 | if (kernfs_ns_enabled(parent)) |
c525aadd | 693 | ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b | 694 | |
324a56e1 | 695 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
696 | |
697 | /* no such entry */ | |
324a56e1 | 698 | if (!kn) { |
19bbb926 | 699 | ret = NULL; |
fd7b9f7b TH |
700 | goto out_unlock; |
701 | } | |
324a56e1 TH |
702 | kernfs_get(kn); |
703 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
704 | |
705 | /* attach dentry and inode */ | |
c637b8ac | 706 | inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
707 | if (!inode) { |
708 | ret = ERR_PTR(-ENOMEM); | |
709 | goto out_unlock; | |
710 | } | |
711 | ||
712 | /* instantiate and hash dentry */ | |
713 | ret = d_materialise_unique(dentry, inode); | |
714 | out_unlock: | |
a797bfc3 | 715 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
716 | return ret; |
717 | } | |
718 | ||
80b9bbef TH |
719 | static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, |
720 | umode_t mode) | |
721 | { | |
722 | struct kernfs_node *parent = dir->i_private; | |
723 | struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops; | |
724 | ||
725 | if (!kdops || !kdops->mkdir) | |
726 | return -EPERM; | |
727 | ||
728 | return kdops->mkdir(parent, dentry->d_name.name, mode); | |
729 | } | |
730 | ||
731 | static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) | |
732 | { | |
733 | struct kernfs_node *kn = dentry->d_fsdata; | |
734 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
735 | ||
736 | if (!kdops || !kdops->rmdir) | |
737 | return -EPERM; | |
738 | ||
739 | return kdops->rmdir(kn); | |
740 | } | |
741 | ||
742 | static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, | |
743 | struct inode *new_dir, struct dentry *new_dentry) | |
744 | { | |
745 | struct kernfs_node *kn = old_dentry->d_fsdata; | |
746 | struct kernfs_node *new_parent = new_dir->i_private; | |
747 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
748 | ||
749 | if (!kdops || !kdops->rename) | |
750 | return -EPERM; | |
751 | ||
752 | return kdops->rename(kn, new_parent, new_dentry->d_name.name); | |
753 | } | |
754 | ||
a797bfc3 | 755 | const struct inode_operations kernfs_dir_iops = { |
c637b8ac TH |
756 | .lookup = kernfs_iop_lookup, |
757 | .permission = kernfs_iop_permission, | |
758 | .setattr = kernfs_iop_setattr, | |
759 | .getattr = kernfs_iop_getattr, | |
760 | .setxattr = kernfs_iop_setxattr, | |
761 | .removexattr = kernfs_iop_removexattr, | |
762 | .getxattr = kernfs_iop_getxattr, | |
763 | .listxattr = kernfs_iop_listxattr, | |
80b9bbef TH |
764 | |
765 | .mkdir = kernfs_iop_mkdir, | |
766 | .rmdir = kernfs_iop_rmdir, | |
767 | .rename = kernfs_iop_rename, | |
fd7b9f7b TH |
768 | }; |
769 | ||
c637b8ac | 770 | static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 771 | { |
324a56e1 | 772 | struct kernfs_node *last; |
fd7b9f7b TH |
773 | |
774 | while (true) { | |
775 | struct rb_node *rbn; | |
776 | ||
777 | last = pos; | |
778 | ||
df23fc39 | 779 | if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b TH |
780 | break; |
781 | ||
adc5e8b5 | 782 | rbn = rb_first(&pos->dir.children); |
fd7b9f7b TH |
783 | if (!rbn) |
784 | break; | |
785 | ||
324a56e1 | 786 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
787 | } |
788 | ||
789 | return last; | |
790 | } | |
791 | ||
792 | /** | |
c637b8ac | 793 | * kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b | 794 | * @pos: the current position (%NULL to initiate traversal) |
324a56e1 | 795 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
796 | * |
797 | * Find the next descendant to visit for post-order traversal of @root's | |
798 | * descendants. @root is included in the iteration and the last node to be | |
799 | * visited. | |
800 | */ | |
c637b8ac TH |
801 | static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, |
802 | struct kernfs_node *root) | |
fd7b9f7b TH |
803 | { |
804 | struct rb_node *rbn; | |
805 | ||
a797bfc3 | 806 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
807 | |
808 | /* if first iteration, visit leftmost descendant which may be root */ | |
809 | if (!pos) | |
c637b8ac | 810 | return kernfs_leftmost_descendant(root); |
fd7b9f7b TH |
811 | |
812 | /* if we visited @root, we're done */ | |
813 | if (pos == root) | |
814 | return NULL; | |
815 | ||
816 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
adc5e8b5 | 817 | rbn = rb_next(&pos->rb); |
fd7b9f7b | 818 | if (rbn) |
c637b8ac | 819 | return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
820 | |
821 | /* no sibling left, visit parent */ | |
adc5e8b5 | 822 | return pos->parent; |
fd7b9f7b TH |
823 | } |
824 | ||
7653fe9d GKH |
825 | static void __kernfs_remove(struct kernfs_addrm_cxt *acxt, |
826 | struct kernfs_node *kn) | |
fd7b9f7b | 827 | { |
4f4b1b64 | 828 | struct kernfs_node *pos, *next; |
fd7b9f7b | 829 | |
ce9b499c GKH |
830 | if (!kn) |
831 | return; | |
832 | ||
c637b8ac | 833 | pr_debug("kernfs %s: removing\n", kn->name); |
fd7b9f7b | 834 | |
4f4b1b64 | 835 | next = NULL; |
fd7b9f7b | 836 | do { |
4f4b1b64 GKH |
837 | pos = next; |
838 | next = kernfs_next_descendant_post(pos, kn); | |
839 | if (pos) | |
840 | kernfs_remove_one(acxt, pos); | |
841 | } while (next); | |
fd7b9f7b TH |
842 | } |
843 | ||
844 | /** | |
324a56e1 TH |
845 | * kernfs_remove - remove a kernfs_node recursively |
846 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 847 | * |
324a56e1 | 848 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 849 | */ |
324a56e1 | 850 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 851 | { |
7653fe9d GKH |
852 | struct kernfs_addrm_cxt acxt; |
853 | ||
854 | kernfs_addrm_start(&acxt); | |
855 | __kernfs_remove(&acxt, kn); | |
856 | kernfs_addrm_finish(&acxt); | |
fd7b9f7b TH |
857 | } |
858 | ||
859 | /** | |
324a56e1 TH |
860 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
861 | * @parent: parent of the target | |
862 | * @name: name of the kernfs_node to remove | |
863 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 864 | * |
324a56e1 TH |
865 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
866 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 867 | */ |
324a56e1 | 868 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
869 | const void *ns) |
870 | { | |
7653fe9d | 871 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 872 | struct kernfs_node *kn; |
fd7b9f7b | 873 | |
324a56e1 | 874 | if (!parent) { |
c637b8ac | 875 | WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n", |
fd7b9f7b TH |
876 | name); |
877 | return -ENOENT; | |
878 | } | |
879 | ||
7653fe9d | 880 | kernfs_addrm_start(&acxt); |
fd7b9f7b | 881 | |
324a56e1 TH |
882 | kn = kernfs_find_ns(parent, name, ns); |
883 | if (kn) | |
7653fe9d | 884 | __kernfs_remove(&acxt, kn); |
fd7b9f7b | 885 | |
7653fe9d | 886 | kernfs_addrm_finish(&acxt); |
fd7b9f7b | 887 | |
324a56e1 | 888 | if (kn) |
fd7b9f7b TH |
889 | return 0; |
890 | else | |
891 | return -ENOENT; | |
892 | } | |
893 | ||
894 | /** | |
895 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 896 | * @kn: target node |
fd7b9f7b TH |
897 | * @new_parent: new parent to put @sd under |
898 | * @new_name: new name | |
899 | * @new_ns: new namespace tag | |
900 | */ | |
324a56e1 | 901 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
902 | const char *new_name, const void *new_ns) |
903 | { | |
904 | int error; | |
905 | ||
d0ae3d43 | 906 | error = -ENOENT; |
ae34372e | 907 | if (!kernfs_get_active(new_parent)) |
d0ae3d43 | 908 | goto out; |
ae34372e TH |
909 | if (!kernfs_get_active(kn)) |
910 | goto out_put_new_parent; | |
911 | ||
912 | mutex_lock(&kernfs_mutex); | |
d0ae3d43 | 913 | |
fd7b9f7b | 914 | error = 0; |
adc5e8b5 TH |
915 | if ((kn->parent == new_parent) && (kn->ns == new_ns) && |
916 | (strcmp(kn->name, new_name) == 0)) | |
ae34372e | 917 | goto out_unlock; /* nothing to rename */ |
fd7b9f7b TH |
918 | |
919 | error = -EEXIST; | |
920 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
ae34372e | 921 | goto out_unlock; |
fd7b9f7b | 922 | |
324a56e1 | 923 | /* rename kernfs_node */ |
adc5e8b5 | 924 | if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b TH |
925 | error = -ENOMEM; |
926 | new_name = kstrdup(new_name, GFP_KERNEL); | |
927 | if (!new_name) | |
ae34372e | 928 | goto out_unlock; |
fd7b9f7b | 929 | |
47a52e91 TH |
930 | if (kn->flags & KERNFS_STATIC_NAME) |
931 | kn->flags &= ~KERNFS_STATIC_NAME; | |
932 | else | |
933 | kfree(kn->name); | |
934 | ||
adc5e8b5 | 935 | kn->name = new_name; |
fd7b9f7b TH |
936 | } |
937 | ||
938 | /* | |
939 | * Move to the appropriate place in the appropriate directories rbtree. | |
940 | */ | |
c637b8ac | 941 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 942 | kernfs_get(new_parent); |
adc5e8b5 TH |
943 | kernfs_put(kn->parent); |
944 | kn->ns = new_ns; | |
c637b8ac | 945 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 946 | kn->parent = new_parent; |
c637b8ac | 947 | kernfs_link_sibling(kn); |
fd7b9f7b TH |
948 | |
949 | error = 0; | |
ae34372e | 950 | out_unlock: |
a797bfc3 | 951 | mutex_unlock(&kernfs_mutex); |
ae34372e TH |
952 | kernfs_put_active(kn); |
953 | out_put_new_parent: | |
954 | kernfs_put_active(new_parent); | |
955 | out: | |
fd7b9f7b TH |
956 | return error; |
957 | } | |
958 | ||
fd7b9f7b | 959 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 960 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 961 | { |
adc5e8b5 | 962 | return (kn->mode >> 12) & 15; |
fd7b9f7b TH |
963 | } |
964 | ||
c637b8ac | 965 | static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b TH |
966 | { |
967 | kernfs_put(filp->private_data); | |
968 | return 0; | |
969 | } | |
970 | ||
c637b8ac | 971 | static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e1 | 972 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b TH |
973 | { |
974 | if (pos) { | |
ae34372e | 975 | int valid = pos->parent == parent && hash == pos->hash; |
fd7b9f7b TH |
976 | kernfs_put(pos); |
977 | if (!valid) | |
978 | pos = NULL; | |
979 | } | |
980 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
adc5e8b5 | 981 | struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b | 982 | while (node) { |
324a56e1 | 983 | pos = rb_to_kn(node); |
fd7b9f7b | 984 | |
adc5e8b5 | 985 | if (hash < pos->hash) |
fd7b9f7b | 986 | node = node->rb_left; |
adc5e8b5 | 987 | else if (hash > pos->hash) |
fd7b9f7b TH |
988 | node = node->rb_right; |
989 | else | |
990 | break; | |
991 | } | |
992 | } | |
993 | /* Skip over entries in the wrong namespace */ | |
adc5e8b5 TH |
994 | while (pos && pos->ns != ns) { |
995 | struct rb_node *node = rb_next(&pos->rb); | |
fd7b9f7b TH |
996 | if (!node) |
997 | pos = NULL; | |
998 | else | |
324a56e1 | 999 | pos = rb_to_kn(node); |
fd7b9f7b TH |
1000 | } |
1001 | return pos; | |
1002 | } | |
1003 | ||
c637b8ac | 1004 | static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e1 | 1005 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b | 1006 | { |
c637b8ac | 1007 | pos = kernfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
1008 | if (pos) |
1009 | do { | |
adc5e8b5 | 1010 | struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b TH |
1011 | if (!node) |
1012 | pos = NULL; | |
1013 | else | |
324a56e1 | 1014 | pos = rb_to_kn(node); |
adc5e8b5 | 1015 | } while (pos && pos->ns != ns); |
fd7b9f7b TH |
1016 | return pos; |
1017 | } | |
1018 | ||
c637b8ac | 1019 | static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b TH |
1020 | { |
1021 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
1022 | struct kernfs_node *parent = dentry->d_fsdata; |
1023 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
1024 | const void *ns = NULL; |
1025 | ||
1026 | if (!dir_emit_dots(file, ctx)) | |
1027 | return 0; | |
a797bfc3 | 1028 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1029 | |
324a56e1 | 1030 | if (kernfs_ns_enabled(parent)) |
c525aadd | 1031 | ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b | 1032 | |
c637b8ac | 1033 | for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 1034 | pos; |
c637b8ac | 1035 | pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b5 | 1036 | const char *name = pos->name; |
fd7b9f7b TH |
1037 | unsigned int type = dt_type(pos); |
1038 | int len = strlen(name); | |
adc5e8b5 | 1039 | ino_t ino = pos->ino; |
fd7b9f7b | 1040 | |
adc5e8b5 | 1041 | ctx->pos = pos->hash; |
fd7b9f7b TH |
1042 | file->private_data = pos; |
1043 | kernfs_get(pos); | |
1044 | ||
a797bfc3 | 1045 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1046 | if (!dir_emit(ctx, name, len, ino, type)) |
1047 | return 0; | |
a797bfc3 | 1048 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1049 | } |
a797bfc3 | 1050 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1051 | file->private_data = NULL; |
1052 | ctx->pos = INT_MAX; | |
1053 | return 0; | |
1054 | } | |
1055 | ||
c637b8ac TH |
1056 | static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset, |
1057 | int whence) | |
fd7b9f7b TH |
1058 | { |
1059 | struct inode *inode = file_inode(file); | |
1060 | loff_t ret; | |
1061 | ||
1062 | mutex_lock(&inode->i_mutex); | |
1063 | ret = generic_file_llseek(file, offset, whence); | |
1064 | mutex_unlock(&inode->i_mutex); | |
1065 | ||
1066 | return ret; | |
1067 | } | |
1068 | ||
a797bfc3 | 1069 | const struct file_operations kernfs_dir_fops = { |
fd7b9f7b | 1070 | .read = generic_read_dir, |
c637b8ac TH |
1071 | .iterate = kernfs_fop_readdir, |
1072 | .release = kernfs_dir_fop_release, | |
1073 | .llseek = kernfs_dir_fop_llseek, | |
fd7b9f7b | 1074 | }; |