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Commit | Line | Data |
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b8441ed2 TH |
1 | /* |
2 | * fs/kernfs/dir.c - kernfs directory implementation | |
3 | * | |
4 | * Copyright (c) 2001-3 Patrick Mochel | |
5 | * Copyright (c) 2007 SUSE Linux Products GmbH | |
6 | * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org> | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | */ | |
fd7b9f7b | 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 | */ |
c637b8ac | 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); |
fd7b9f7b TH |
130 | } |
131 | ||
132 | /** | |
c637b8ac | 133 | * kernfs_get_active - get an active reference to kernfs_node |
324a56e1 | 134 | * @kn: kernfs_node to get an active reference to |
fd7b9f7b | 135 | * |
324a56e1 | 136 | * Get an active reference of @kn. This function is noop if @kn |
fd7b9f7b TH |
137 | * is NULL. |
138 | * | |
139 | * RETURNS: | |
324a56e1 | 140 | * Pointer to @kn on success, NULL on failure. |
fd7b9f7b | 141 | */ |
c637b8ac | 142 | struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) |
fd7b9f7b | 143 | { |
324a56e1 | 144 | if (unlikely(!kn)) |
fd7b9f7b TH |
145 | return NULL; |
146 | ||
adc5e8b5 | 147 | if (!atomic_inc_unless_negative(&kn->active)) |
fd7b9f7b TH |
148 | return NULL; |
149 | ||
a69d001c | 150 | if (kernfs_lockdep(kn)) |
324a56e1 TH |
151 | rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_); |
152 | return kn; | |
fd7b9f7b TH |
153 | } |
154 | ||
155 | /** | |
c637b8ac | 156 | * kernfs_put_active - put an active reference to kernfs_node |
324a56e1 | 157 | * @kn: kernfs_node to put an active reference to |
fd7b9f7b | 158 | * |
324a56e1 | 159 | * Put an active reference to @kn. This function is noop if @kn |
fd7b9f7b TH |
160 | * is NULL. |
161 | */ | |
c637b8ac | 162 | void kernfs_put_active(struct kernfs_node *kn) |
fd7b9f7b | 163 | { |
ea1c472d | 164 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b TH |
165 | int v; |
166 | ||
324a56e1 | 167 | if (unlikely(!kn)) |
fd7b9f7b TH |
168 | return; |
169 | ||
a69d001c | 170 | if (kernfs_lockdep(kn)) |
324a56e1 | 171 | rwsem_release(&kn->dep_map, 1, _RET_IP_); |
adc5e8b5 | 172 | v = atomic_dec_return(&kn->active); |
df23fc39 | 173 | if (likely(v != KN_DEACTIVATED_BIAS)) |
fd7b9f7b TH |
174 | return; |
175 | ||
ea1c472d | 176 | wake_up_all(&root->deactivate_waitq); |
fd7b9f7b TH |
177 | } |
178 | ||
179 | /** | |
c637b8ac | 180 | * kernfs_deactivate - deactivate kernfs_node |
324a56e1 | 181 | * @kn: kernfs_node to deactivate |
fd7b9f7b TH |
182 | * |
183 | * Deny new active references and drain existing ones. | |
184 | */ | |
c637b8ac | 185 | static void kernfs_deactivate(struct kernfs_node *kn) |
fd7b9f7b | 186 | { |
ea1c472d | 187 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b | 188 | |
df23fc39 | 189 | BUG_ON(!(kn->flags & KERNFS_REMOVED)); |
fd7b9f7b | 190 | |
ea1c472d TH |
191 | atomic_add(KN_DEACTIVATED_BIAS, &kn->active); |
192 | ||
a69d001c TH |
193 | if (kernfs_lockdep(kn)) { |
194 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); | |
195 | if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS) | |
196 | lock_contended(&kn->dep_map, _RET_IP_); | |
197 | } | |
ea1c472d TH |
198 | |
199 | wait_event(root->deactivate_waitq, | |
200 | atomic_read(&kn->active) == KN_DEACTIVATED_BIAS); | |
fd7b9f7b | 201 | |
a69d001c TH |
202 | if (kernfs_lockdep(kn)) { |
203 | lock_acquired(&kn->dep_map, _RET_IP_); | |
204 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
205 | } | |
fd7b9f7b TH |
206 | } |
207 | ||
fd7b9f7b | 208 | /** |
324a56e1 TH |
209 | * kernfs_get - get a reference count on a kernfs_node |
210 | * @kn: the target kernfs_node | |
fd7b9f7b | 211 | */ |
324a56e1 | 212 | void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b | 213 | { |
324a56e1 | 214 | if (kn) { |
adc5e8b5 TH |
215 | WARN_ON(!atomic_read(&kn->count)); |
216 | atomic_inc(&kn->count); | |
fd7b9f7b TH |
217 | } |
218 | } | |
219 | EXPORT_SYMBOL_GPL(kernfs_get); | |
220 | ||
221 | /** | |
324a56e1 TH |
222 | * kernfs_put - put a reference count on a kernfs_node |
223 | * @kn: the target kernfs_node | |
fd7b9f7b | 224 | * |
324a56e1 | 225 | * Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b | 226 | */ |
324a56e1 | 227 | void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b | 228 | { |
324a56e1 | 229 | struct kernfs_node *parent; |
ba7443bc | 230 | struct kernfs_root *root; |
fd7b9f7b | 231 | |
adc5e8b5 | 232 | if (!kn || !atomic_dec_and_test(&kn->count)) |
fd7b9f7b | 233 | return; |
324a56e1 | 234 | root = kernfs_root(kn); |
fd7b9f7b TH |
235 | repeat: |
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 | |
c637b8ac TH |
241 | WARN(!(kn->flags & KERNFS_REMOVED), "kernfs: free using entry: %s/%s\n", |
242 | parent ? parent->name : "", kn->name); | |
324a56e1 | 243 | |
df23fc39 | 244 | if (kernfs_type(kn) == KERNFS_LINK) |
adc5e8b5 | 245 | kernfs_put(kn->symlink.target_kn); |
2063d608 | 246 | if (!(kn->flags & KERNFS_STATIC_NAME)) |
adc5e8b5 TH |
247 | kfree(kn->name); |
248 | if (kn->iattr) { | |
249 | if (kn->iattr->ia_secdata) | |
250 | security_release_secctx(kn->iattr->ia_secdata, | |
251 | kn->iattr->ia_secdata_len); | |
252 | simple_xattrs_free(&kn->iattr->xattrs); | |
2322392b | 253 | } |
adc5e8b5 TH |
254 | kfree(kn->iattr); |
255 | ida_simple_remove(&root->ino_ida, kn->ino); | |
a797bfc3 | 256 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b | 257 | |
324a56e1 TH |
258 | kn = parent; |
259 | if (kn) { | |
adc5e8b5 | 260 | if (atomic_dec_and_test(&kn->count)) |
ba7443bc TH |
261 | goto repeat; |
262 | } else { | |
324a56e1 | 263 | /* just released the root kn, free @root too */ |
bc755553 | 264 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
265 | kfree(root); |
266 | } | |
fd7b9f7b TH |
267 | } |
268 | EXPORT_SYMBOL_GPL(kernfs_put); | |
269 | ||
c637b8ac | 270 | static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags) |
fd7b9f7b | 271 | { |
324a56e1 | 272 | struct kernfs_node *kn; |
fd7b9f7b TH |
273 | |
274 | if (flags & LOOKUP_RCU) | |
275 | return -ECHILD; | |
276 | ||
19bbb926 TH |
277 | /* Always perform fresh lookup for negatives */ |
278 | if (!dentry->d_inode) | |
279 | goto out_bad_unlocked; | |
280 | ||
324a56e1 | 281 | kn = dentry->d_fsdata; |
a797bfc3 | 282 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 283 | |
c637b8ac | 284 | /* The kernfs node has been deleted */ |
df23fc39 | 285 | if (kn->flags & KERNFS_REMOVED) |
fd7b9f7b TH |
286 | goto out_bad; |
287 | ||
c637b8ac | 288 | /* The kernfs node has been moved? */ |
adc5e8b5 | 289 | if (dentry->d_parent->d_fsdata != kn->parent) |
fd7b9f7b TH |
290 | goto out_bad; |
291 | ||
c637b8ac | 292 | /* The kernfs node has been renamed */ |
adc5e8b5 | 293 | if (strcmp(dentry->d_name.name, kn->name) != 0) |
fd7b9f7b TH |
294 | goto out_bad; |
295 | ||
c637b8ac | 296 | /* The kernfs node has been moved to a different namespace */ |
adc5e8b5 | 297 | if (kn->parent && kernfs_ns_enabled(kn->parent) && |
c525aadd | 298 | kernfs_info(dentry->d_sb)->ns != kn->ns) |
fd7b9f7b TH |
299 | goto out_bad; |
300 | ||
a797bfc3 | 301 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
302 | out_valid: |
303 | return 1; | |
304 | out_bad: | |
a797bfc3 | 305 | mutex_unlock(&kernfs_mutex); |
19bbb926 TH |
306 | out_bad_unlocked: |
307 | /* | |
308 | * @dentry doesn't match the underlying kernfs node, drop the | |
309 | * dentry and force lookup. If we have submounts we must allow the | |
310 | * vfs caches to lie about the state of the filesystem to prevent | |
311 | * leaks and other nasty things, so use check_submounts_and_drop() | |
312 | * instead of d_drop(). | |
fd7b9f7b TH |
313 | */ |
314 | if (check_submounts_and_drop(dentry) != 0) | |
315 | goto out_valid; | |
316 | ||
317 | return 0; | |
318 | } | |
319 | ||
c637b8ac | 320 | static void kernfs_dop_release(struct dentry *dentry) |
fd7b9f7b TH |
321 | { |
322 | kernfs_put(dentry->d_fsdata); | |
323 | } | |
324 | ||
a797bfc3 | 325 | const struct dentry_operations kernfs_dops = { |
c637b8ac | 326 | .d_revalidate = kernfs_dop_revalidate, |
c637b8ac | 327 | .d_release = kernfs_dop_release, |
fd7b9f7b TH |
328 | }; |
329 | ||
c637b8ac | 330 | struct kernfs_node *kernfs_new_node(struct kernfs_root *root, const char *name, |
2063d608 | 331 | umode_t mode, unsigned flags) |
fd7b9f7b TH |
332 | { |
333 | char *dup_name = NULL; | |
324a56e1 | 334 | struct kernfs_node *kn; |
bc755553 | 335 | int ret; |
fd7b9f7b | 336 | |
2063d608 | 337 | if (!(flags & KERNFS_STATIC_NAME)) { |
fd7b9f7b TH |
338 | name = dup_name = kstrdup(name, GFP_KERNEL); |
339 | if (!name) | |
340 | return NULL; | |
341 | } | |
342 | ||
a797bfc3 | 343 | kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e1 | 344 | if (!kn) |
fd7b9f7b TH |
345 | goto err_out1; |
346 | ||
bc755553 TH |
347 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
348 | if (ret < 0) | |
fd7b9f7b | 349 | goto err_out2; |
adc5e8b5 | 350 | kn->ino = ret; |
fd7b9f7b | 351 | |
adc5e8b5 TH |
352 | atomic_set(&kn->count, 1); |
353 | atomic_set(&kn->active, 0); | |
fd7b9f7b | 354 | |
adc5e8b5 TH |
355 | kn->name = name; |
356 | kn->mode = mode; | |
2063d608 | 357 | kn->flags = flags | KERNFS_REMOVED; |
fd7b9f7b | 358 | |
324a56e1 | 359 | return kn; |
fd7b9f7b TH |
360 | |
361 | err_out2: | |
a797bfc3 | 362 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b TH |
363 | err_out1: |
364 | kfree(dup_name); | |
365 | return NULL; | |
366 | } | |
367 | ||
368 | /** | |
c637b8ac | 369 | * kernfs_addrm_start - prepare for kernfs_node add/remove |
c525aadd | 370 | * @acxt: pointer to kernfs_addrm_cxt to be used |
fd7b9f7b TH |
371 | * |
372 | * This function is called when the caller is about to add or remove | |
a797bfc3 TH |
373 | * kernfs_node. This function acquires kernfs_mutex. @acxt is used |
374 | * to keep and pass context to other addrm functions. | |
fd7b9f7b TH |
375 | * |
376 | * LOCKING: | |
a797bfc3 | 377 | * Kernel thread context (may sleep). kernfs_mutex is locked on |
fd7b9f7b TH |
378 | * return. |
379 | */ | |
c637b8ac | 380 | void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt) |
a797bfc3 | 381 | __acquires(kernfs_mutex) |
fd7b9f7b TH |
382 | { |
383 | memset(acxt, 0, sizeof(*acxt)); | |
384 | ||
a797bfc3 | 385 | mutex_lock(&kernfs_mutex); |
fd7b9f7b TH |
386 | } |
387 | ||
388 | /** | |
c637b8ac | 389 | * kernfs_add_one - add kernfs_node to parent without warning |
fd7b9f7b | 390 | * @acxt: addrm context to use |
324a56e1 TH |
391 | * @kn: kernfs_node to be added |
392 | * @parent: the parent kernfs_node to add @kn to | |
fd7b9f7b | 393 | * |
adc5e8b5 TH |
394 | * Get @parent and set @kn->parent to it and increment nlink of the |
395 | * parent inode if @kn is a directory and link into the children list | |
396 | * of the parent. | |
fd7b9f7b TH |
397 | * |
398 | * This function should be called between calls to | |
c637b8ac TH |
399 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be passed |
400 | * the same @acxt as passed to kernfs_addrm_start(). | |
fd7b9f7b TH |
401 | * |
402 | * LOCKING: | |
c637b8ac | 403 | * Determined by kernfs_addrm_start(). |
fd7b9f7b TH |
404 | * |
405 | * RETURNS: | |
406 | * 0 on success, -EEXIST if entry with the given name already | |
407 | * exists. | |
408 | */ | |
c637b8ac | 409 | int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn, |
324a56e1 | 410 | struct kernfs_node *parent) |
fd7b9f7b | 411 | { |
324a56e1 | 412 | bool has_ns = kernfs_ns_enabled(parent); |
c525aadd | 413 | struct kernfs_iattrs *ps_iattr; |
fd7b9f7b TH |
414 | int ret; |
415 | ||
adc5e8b5 | 416 | if (has_ns != (bool)kn->ns) { |
c637b8ac | 417 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", |
adc5e8b5 | 418 | has_ns ? "required" : "invalid", parent->name, kn->name); |
fd7b9f7b TH |
419 | return -EINVAL; |
420 | } | |
421 | ||
df23fc39 | 422 | if (kernfs_type(parent) != KERNFS_DIR) |
fd7b9f7b TH |
423 | return -EINVAL; |
424 | ||
d0ae3d43 TH |
425 | if (parent->flags & KERNFS_REMOVED) |
426 | return -ENOENT; | |
427 | ||
c637b8ac | 428 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 429 | kn->parent = parent; |
324a56e1 | 430 | kernfs_get(parent); |
fd7b9f7b | 431 | |
c637b8ac | 432 | ret = kernfs_link_sibling(kn); |
fd7b9f7b TH |
433 | if (ret) |
434 | return ret; | |
435 | ||
436 | /* Update timestamps on the parent */ | |
adc5e8b5 | 437 | ps_iattr = parent->iattr; |
fd7b9f7b TH |
438 | if (ps_iattr) { |
439 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
440 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
441 | } | |
442 | ||
443 | /* Mark the entry added into directory tree */ | |
df23fc39 | 444 | kn->flags &= ~KERNFS_REMOVED; |
fd7b9f7b TH |
445 | |
446 | return 0; | |
447 | } | |
448 | ||
449 | /** | |
c637b8ac | 450 | * kernfs_remove_one - remove kernfs_node from parent |
fd7b9f7b | 451 | * @acxt: addrm context to use |
324a56e1 | 452 | * @kn: kernfs_node to be removed |
fd7b9f7b | 453 | * |
324a56e1 TH |
454 | * Mark @kn removed and drop nlink of parent inode if @kn is a |
455 | * directory. @kn is unlinked from the children list. | |
fd7b9f7b TH |
456 | * |
457 | * This function should be called between calls to | |
c637b8ac TH |
458 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be |
459 | * passed the same @acxt as passed to kernfs_addrm_start(). | |
fd7b9f7b TH |
460 | * |
461 | * LOCKING: | |
c637b8ac | 462 | * Determined by kernfs_addrm_start(). |
fd7b9f7b | 463 | */ |
c637b8ac TH |
464 | static void kernfs_remove_one(struct kernfs_addrm_cxt *acxt, |
465 | struct kernfs_node *kn) | |
fd7b9f7b | 466 | { |
c525aadd | 467 | struct kernfs_iattrs *ps_iattr; |
fd7b9f7b TH |
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 | */ | |
df23fc39 | 473 | if (kn->flags & KERNFS_REMOVED) |
fd7b9f7b TH |
474 | return; |
475 | ||
adc5e8b5 | 476 | if (kn->parent) { |
c637b8ac | 477 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 478 | |
ba7443bc | 479 | /* Update timestamps on the parent */ |
adc5e8b5 | 480 | ps_iattr = kn->parent->iattr; |
ba7443bc TH |
481 | if (ps_iattr) { |
482 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
483 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
484 | } | |
fd7b9f7b TH |
485 | } |
486 | ||
df23fc39 | 487 | kn->flags |= KERNFS_REMOVED; |
324a56e1 TH |
488 | kn->u.removed_list = acxt->removed; |
489 | acxt->removed = kn; | |
fd7b9f7b TH |
490 | } |
491 | ||
492 | /** | |
c637b8ac | 493 | * kernfs_addrm_finish - finish up kernfs_node add/remove |
fd7b9f7b TH |
494 | * @acxt: addrm context to finish up |
495 | * | |
324a56e1 | 496 | * Finish up kernfs_node add/remove. Resources acquired by |
c637b8ac | 497 | * kernfs_addrm_start() are released and removed kernfs_nodes are |
fd7b9f7b TH |
498 | * cleaned up. |
499 | * | |
500 | * LOCKING: | |
a797bfc3 | 501 | * kernfs_mutex is released. |
fd7b9f7b | 502 | */ |
c637b8ac | 503 | void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt) |
a797bfc3 | 504 | __releases(kernfs_mutex) |
fd7b9f7b | 505 | { |
c637b8ac | 506 | /* release resources acquired by kernfs_addrm_start() */ |
a797bfc3 | 507 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 508 | |
324a56e1 | 509 | /* kill removed kernfs_nodes */ |
fd7b9f7b | 510 | while (acxt->removed) { |
324a56e1 | 511 | struct kernfs_node *kn = acxt->removed; |
fd7b9f7b | 512 | |
324a56e1 | 513 | acxt->removed = kn->u.removed_list; |
fd7b9f7b | 514 | |
c637b8ac TH |
515 | kernfs_deactivate(kn); |
516 | kernfs_unmap_bin_file(kn); | |
324a56e1 | 517 | kernfs_put(kn); |
fd7b9f7b TH |
518 | } |
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 | ||
df23fc39 | 613 | kn->flags &= ~KERNFS_REMOVED; |
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 | { |
c525aadd | 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 */ | |
c637b8ac TH |
665 | kernfs_addrm_start(&acxt); |
666 | rc = kernfs_add_one(&acxt, kn, parent); | |
667 | kernfs_addrm_finish(&acxt); | |
fd7b9f7b TH |
668 | |
669 | if (!rc) | |
324a56e1 | 670 | return kn; |
fd7b9f7b | 671 | |
324a56e1 | 672 | kernfs_put(kn); |
fd7b9f7b TH |
673 | return ERR_PTR(rc); |
674 | } | |
675 | ||
c637b8ac TH |
676 | static struct dentry *kernfs_iop_lookup(struct inode *dir, |
677 | struct dentry *dentry, | |
678 | unsigned int flags) | |
fd7b9f7b | 679 | { |
19bbb926 | 680 | struct dentry *ret; |
324a56e1 TH |
681 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
682 | struct kernfs_node *kn; | |
fd7b9f7b TH |
683 | struct inode *inode; |
684 | const void *ns = NULL; | |
685 | ||
a797bfc3 | 686 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 687 | |
324a56e1 | 688 | if (kernfs_ns_enabled(parent)) |
c525aadd | 689 | ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b | 690 | |
324a56e1 | 691 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
692 | |
693 | /* no such entry */ | |
324a56e1 | 694 | if (!kn) { |
19bbb926 | 695 | ret = NULL; |
fd7b9f7b TH |
696 | goto out_unlock; |
697 | } | |
324a56e1 TH |
698 | kernfs_get(kn); |
699 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
700 | |
701 | /* attach dentry and inode */ | |
c637b8ac | 702 | inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
703 | if (!inode) { |
704 | ret = ERR_PTR(-ENOMEM); | |
705 | goto out_unlock; | |
706 | } | |
707 | ||
708 | /* instantiate and hash dentry */ | |
709 | ret = d_materialise_unique(dentry, inode); | |
710 | out_unlock: | |
a797bfc3 | 711 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
712 | return ret; |
713 | } | |
714 | ||
80b9bbef TH |
715 | static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, |
716 | umode_t mode) | |
717 | { | |
718 | struct kernfs_node *parent = dir->i_private; | |
719 | struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops; | |
720 | ||
721 | if (!kdops || !kdops->mkdir) | |
722 | return -EPERM; | |
723 | ||
724 | return kdops->mkdir(parent, dentry->d_name.name, mode); | |
725 | } | |
726 | ||
727 | static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) | |
728 | { | |
729 | struct kernfs_node *kn = dentry->d_fsdata; | |
730 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
731 | ||
732 | if (!kdops || !kdops->rmdir) | |
733 | return -EPERM; | |
734 | ||
735 | return kdops->rmdir(kn); | |
736 | } | |
737 | ||
738 | static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, | |
739 | struct inode *new_dir, struct dentry *new_dentry) | |
740 | { | |
741 | struct kernfs_node *kn = old_dentry->d_fsdata; | |
742 | struct kernfs_node *new_parent = new_dir->i_private; | |
743 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
744 | ||
745 | if (!kdops || !kdops->rename) | |
746 | return -EPERM; | |
747 | ||
748 | return kdops->rename(kn, new_parent, new_dentry->d_name.name); | |
749 | } | |
750 | ||
a797bfc3 | 751 | const struct inode_operations kernfs_dir_iops = { |
c637b8ac TH |
752 | .lookup = kernfs_iop_lookup, |
753 | .permission = kernfs_iop_permission, | |
754 | .setattr = kernfs_iop_setattr, | |
755 | .getattr = kernfs_iop_getattr, | |
756 | .setxattr = kernfs_iop_setxattr, | |
757 | .removexattr = kernfs_iop_removexattr, | |
758 | .getxattr = kernfs_iop_getxattr, | |
759 | .listxattr = kernfs_iop_listxattr, | |
80b9bbef TH |
760 | |
761 | .mkdir = kernfs_iop_mkdir, | |
762 | .rmdir = kernfs_iop_rmdir, | |
763 | .rename = kernfs_iop_rename, | |
fd7b9f7b TH |
764 | }; |
765 | ||
c637b8ac | 766 | static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 767 | { |
324a56e1 | 768 | struct kernfs_node *last; |
fd7b9f7b TH |
769 | |
770 | while (true) { | |
771 | struct rb_node *rbn; | |
772 | ||
773 | last = pos; | |
774 | ||
df23fc39 | 775 | if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b TH |
776 | break; |
777 | ||
adc5e8b5 | 778 | rbn = rb_first(&pos->dir.children); |
fd7b9f7b TH |
779 | if (!rbn) |
780 | break; | |
781 | ||
324a56e1 | 782 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
783 | } |
784 | ||
785 | return last; | |
786 | } | |
787 | ||
788 | /** | |
c637b8ac | 789 | * kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b | 790 | * @pos: the current position (%NULL to initiate traversal) |
324a56e1 | 791 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
792 | * |
793 | * Find the next descendant to visit for post-order traversal of @root's | |
794 | * descendants. @root is included in the iteration and the last node to be | |
795 | * visited. | |
796 | */ | |
c637b8ac TH |
797 | static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, |
798 | struct kernfs_node *root) | |
fd7b9f7b TH |
799 | { |
800 | struct rb_node *rbn; | |
801 | ||
a797bfc3 | 802 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
803 | |
804 | /* if first iteration, visit leftmost descendant which may be root */ | |
805 | if (!pos) | |
c637b8ac | 806 | return kernfs_leftmost_descendant(root); |
fd7b9f7b TH |
807 | |
808 | /* if we visited @root, we're done */ | |
809 | if (pos == root) | |
810 | return NULL; | |
811 | ||
812 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
adc5e8b5 | 813 | rbn = rb_next(&pos->rb); |
fd7b9f7b | 814 | if (rbn) |
c637b8ac | 815 | return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
816 | |
817 | /* no sibling left, visit parent */ | |
adc5e8b5 | 818 | return pos->parent; |
fd7b9f7b TH |
819 | } |
820 | ||
c525aadd | 821 | static void __kernfs_remove(struct kernfs_addrm_cxt *acxt, |
324a56e1 | 822 | struct kernfs_node *kn) |
fd7b9f7b | 823 | { |
324a56e1 | 824 | struct kernfs_node *pos, *next; |
fd7b9f7b | 825 | |
324a56e1 | 826 | if (!kn) |
fd7b9f7b TH |
827 | return; |
828 | ||
c637b8ac | 829 | pr_debug("kernfs %s: removing\n", kn->name); |
fd7b9f7b TH |
830 | |
831 | next = NULL; | |
832 | do { | |
833 | pos = next; | |
c637b8ac | 834 | next = kernfs_next_descendant_post(pos, kn); |
fd7b9f7b | 835 | if (pos) |
c637b8ac | 836 | kernfs_remove_one(acxt, pos); |
fd7b9f7b TH |
837 | } while (next); |
838 | } | |
839 | ||
840 | /** | |
324a56e1 TH |
841 | * kernfs_remove - remove a kernfs_node recursively |
842 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 843 | * |
324a56e1 | 844 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 845 | */ |
324a56e1 | 846 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 847 | { |
c525aadd | 848 | struct kernfs_addrm_cxt acxt; |
fd7b9f7b | 849 | |
c637b8ac | 850 | kernfs_addrm_start(&acxt); |
324a56e1 | 851 | __kernfs_remove(&acxt, kn); |
c637b8ac | 852 | kernfs_addrm_finish(&acxt); |
fd7b9f7b TH |
853 | } |
854 | ||
855 | /** | |
324a56e1 TH |
856 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
857 | * @parent: parent of the target | |
858 | * @name: name of the kernfs_node to remove | |
859 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 860 | * |
324a56e1 TH |
861 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
862 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 863 | */ |
324a56e1 | 864 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
865 | const void *ns) |
866 | { | |
c525aadd | 867 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 868 | struct kernfs_node *kn; |
fd7b9f7b | 869 | |
324a56e1 | 870 | if (!parent) { |
c637b8ac | 871 | WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n", |
fd7b9f7b TH |
872 | name); |
873 | return -ENOENT; | |
874 | } | |
875 | ||
c637b8ac | 876 | kernfs_addrm_start(&acxt); |
fd7b9f7b | 877 | |
324a56e1 TH |
878 | kn = kernfs_find_ns(parent, name, ns); |
879 | if (kn) | |
880 | __kernfs_remove(&acxt, kn); | |
fd7b9f7b | 881 | |
c637b8ac | 882 | kernfs_addrm_finish(&acxt); |
fd7b9f7b | 883 | |
324a56e1 | 884 | if (kn) |
fd7b9f7b TH |
885 | return 0; |
886 | else | |
887 | return -ENOENT; | |
888 | } | |
889 | ||
890 | /** | |
891 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 892 | * @kn: target node |
fd7b9f7b TH |
893 | * @new_parent: new parent to put @sd under |
894 | * @new_name: new name | |
895 | * @new_ns: new namespace tag | |
896 | */ | |
324a56e1 | 897 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
898 | const char *new_name, const void *new_ns) |
899 | { | |
900 | int error; | |
901 | ||
a797bfc3 | 902 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 903 | |
d0ae3d43 TH |
904 | error = -ENOENT; |
905 | if ((kn->flags | new_parent->flags) & KERNFS_REMOVED) | |
906 | goto out; | |
907 | ||
fd7b9f7b | 908 | error = 0; |
adc5e8b5 TH |
909 | if ((kn->parent == new_parent) && (kn->ns == new_ns) && |
910 | (strcmp(kn->name, new_name) == 0)) | |
fd7b9f7b TH |
911 | goto out; /* nothing to rename */ |
912 | ||
913 | error = -EEXIST; | |
914 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
915 | goto out; | |
916 | ||
324a56e1 | 917 | /* rename kernfs_node */ |
adc5e8b5 | 918 | if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b TH |
919 | error = -ENOMEM; |
920 | new_name = kstrdup(new_name, GFP_KERNEL); | |
921 | if (!new_name) | |
922 | goto out; | |
923 | ||
47a52e91 TH |
924 | if (kn->flags & KERNFS_STATIC_NAME) |
925 | kn->flags &= ~KERNFS_STATIC_NAME; | |
926 | else | |
927 | kfree(kn->name); | |
928 | ||
adc5e8b5 | 929 | kn->name = new_name; |
fd7b9f7b TH |
930 | } |
931 | ||
932 | /* | |
933 | * Move to the appropriate place in the appropriate directories rbtree. | |
934 | */ | |
c637b8ac | 935 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 936 | kernfs_get(new_parent); |
adc5e8b5 TH |
937 | kernfs_put(kn->parent); |
938 | kn->ns = new_ns; | |
c637b8ac | 939 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 940 | kn->parent = new_parent; |
c637b8ac | 941 | kernfs_link_sibling(kn); |
fd7b9f7b TH |
942 | |
943 | error = 0; | |
944 | out: | |
a797bfc3 | 945 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
946 | return error; |
947 | } | |
948 | ||
fd7b9f7b | 949 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 950 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 951 | { |
adc5e8b5 | 952 | return (kn->mode >> 12) & 15; |
fd7b9f7b TH |
953 | } |
954 | ||
c637b8ac | 955 | static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b TH |
956 | { |
957 | kernfs_put(filp->private_data); | |
958 | return 0; | |
959 | } | |
960 | ||
c637b8ac | 961 | static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e1 | 962 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b TH |
963 | { |
964 | if (pos) { | |
df23fc39 | 965 | int valid = !(pos->flags & KERNFS_REMOVED) && |
adc5e8b5 | 966 | pos->parent == parent && hash == pos->hash; |
fd7b9f7b TH |
967 | kernfs_put(pos); |
968 | if (!valid) | |
969 | pos = NULL; | |
970 | } | |
971 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
adc5e8b5 | 972 | struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b | 973 | while (node) { |
324a56e1 | 974 | pos = rb_to_kn(node); |
fd7b9f7b | 975 | |
adc5e8b5 | 976 | if (hash < pos->hash) |
fd7b9f7b | 977 | node = node->rb_left; |
adc5e8b5 | 978 | else if (hash > pos->hash) |
fd7b9f7b TH |
979 | node = node->rb_right; |
980 | else | |
981 | break; | |
982 | } | |
983 | } | |
984 | /* Skip over entries in the wrong namespace */ | |
adc5e8b5 TH |
985 | while (pos && pos->ns != ns) { |
986 | struct rb_node *node = rb_next(&pos->rb); | |
fd7b9f7b TH |
987 | if (!node) |
988 | pos = NULL; | |
989 | else | |
324a56e1 | 990 | pos = rb_to_kn(node); |
fd7b9f7b TH |
991 | } |
992 | return pos; | |
993 | } | |
994 | ||
c637b8ac | 995 | static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e1 | 996 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b | 997 | { |
c637b8ac | 998 | pos = kernfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
999 | if (pos) |
1000 | do { | |
adc5e8b5 | 1001 | struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b TH |
1002 | if (!node) |
1003 | pos = NULL; | |
1004 | else | |
324a56e1 | 1005 | pos = rb_to_kn(node); |
adc5e8b5 | 1006 | } while (pos && pos->ns != ns); |
fd7b9f7b TH |
1007 | return pos; |
1008 | } | |
1009 | ||
c637b8ac | 1010 | static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b TH |
1011 | { |
1012 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
1013 | struct kernfs_node *parent = dentry->d_fsdata; |
1014 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
1015 | const void *ns = NULL; |
1016 | ||
1017 | if (!dir_emit_dots(file, ctx)) | |
1018 | return 0; | |
a797bfc3 | 1019 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1020 | |
324a56e1 | 1021 | if (kernfs_ns_enabled(parent)) |
c525aadd | 1022 | ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b | 1023 | |
c637b8ac | 1024 | for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 1025 | pos; |
c637b8ac | 1026 | pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b5 | 1027 | const char *name = pos->name; |
fd7b9f7b TH |
1028 | unsigned int type = dt_type(pos); |
1029 | int len = strlen(name); | |
adc5e8b5 | 1030 | ino_t ino = pos->ino; |
fd7b9f7b | 1031 | |
adc5e8b5 | 1032 | ctx->pos = pos->hash; |
fd7b9f7b TH |
1033 | file->private_data = pos; |
1034 | kernfs_get(pos); | |
1035 | ||
a797bfc3 | 1036 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1037 | if (!dir_emit(ctx, name, len, ino, type)) |
1038 | return 0; | |
a797bfc3 | 1039 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1040 | } |
a797bfc3 | 1041 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1042 | file->private_data = NULL; |
1043 | ctx->pos = INT_MAX; | |
1044 | return 0; | |
1045 | } | |
1046 | ||
c637b8ac TH |
1047 | static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset, |
1048 | int whence) | |
fd7b9f7b TH |
1049 | { |
1050 | struct inode *inode = file_inode(file); | |
1051 | loff_t ret; | |
1052 | ||
1053 | mutex_lock(&inode->i_mutex); | |
1054 | ret = generic_file_llseek(file, offset, whence); | |
1055 | mutex_unlock(&inode->i_mutex); | |
1056 | ||
1057 | return ret; | |
1058 | } | |
1059 | ||
a797bfc3 | 1060 | const struct file_operations kernfs_dir_fops = { |
fd7b9f7b | 1061 | .read = generic_read_dir, |
c637b8ac TH |
1062 | .iterate = kernfs_fop_readdir, |
1063 | .release = kernfs_dir_fop_release, | |
1064 | .llseek = kernfs_dir_fop_llseek, | |
fd7b9f7b | 1065 | }; |