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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 TH |
10 | |
11 | #include <linux/fs.h> | |
12 | #include <linux/namei.h> | |
13 | #include <linux/idr.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/security.h> | |
16 | #include <linux/hash.h> | |
17 | ||
18 | #include "kernfs-internal.h" | |
19 | ||
a797bfc3 | 20 | DEFINE_MUTEX(kernfs_mutex); |
fd7b9f7b | 21 | |
adc5e8b5 | 22 | #define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb) |
fd7b9f7b | 23 | |
fd7b9f7b | 24 | /** |
c637b8ac | 25 | * kernfs_name_hash |
fd7b9f7b TH |
26 | * @name: Null terminated string to hash |
27 | * @ns: Namespace tag to hash | |
28 | * | |
29 | * Returns 31 bit hash of ns + name (so it fits in an off_t ) | |
30 | */ | |
c637b8ac | 31 | static unsigned int kernfs_name_hash(const char *name, const void *ns) |
fd7b9f7b TH |
32 | { |
33 | unsigned long hash = init_name_hash(); | |
34 | unsigned int len = strlen(name); | |
35 | while (len--) | |
36 | hash = partial_name_hash(*name++, hash); | |
37 | hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31)); | |
38 | hash &= 0x7fffffffU; | |
39 | /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ | |
40 | if (hash < 1) | |
41 | hash += 2; | |
42 | if (hash >= INT_MAX) | |
43 | hash = INT_MAX - 1; | |
44 | return hash; | |
45 | } | |
46 | ||
c637b8ac TH |
47 | static int kernfs_name_compare(unsigned int hash, const char *name, |
48 | const void *ns, const struct kernfs_node *kn) | |
fd7b9f7b | 49 | { |
adc5e8b5 TH |
50 | if (hash != kn->hash) |
51 | return hash - kn->hash; | |
52 | if (ns != kn->ns) | |
53 | return ns - kn->ns; | |
54 | return strcmp(name, kn->name); | |
fd7b9f7b TH |
55 | } |
56 | ||
c637b8ac TH |
57 | static int kernfs_sd_compare(const struct kernfs_node *left, |
58 | const struct kernfs_node *right) | |
fd7b9f7b | 59 | { |
c637b8ac | 60 | return kernfs_name_compare(left->hash, left->name, left->ns, right); |
fd7b9f7b TH |
61 | } |
62 | ||
63 | /** | |
c637b8ac | 64 | * kernfs_link_sibling - link kernfs_node into sibling rbtree |
324a56e1 | 65 | * @kn: kernfs_node of interest |
fd7b9f7b | 66 | * |
324a56e1 | 67 | * Link @kn into its sibling rbtree which starts from |
adc5e8b5 | 68 | * @kn->parent->dir.children. |
fd7b9f7b TH |
69 | * |
70 | * Locking: | |
a797bfc3 | 71 | * mutex_lock(kernfs_mutex) |
fd7b9f7b TH |
72 | * |
73 | * RETURNS: | |
74 | * 0 on susccess -EEXIST on failure. | |
75 | */ | |
c637b8ac | 76 | static int kernfs_link_sibling(struct kernfs_node *kn) |
fd7b9f7b | 77 | { |
adc5e8b5 | 78 | struct rb_node **node = &kn->parent->dir.children.rb_node; |
fd7b9f7b TH |
79 | struct rb_node *parent = NULL; |
80 | ||
df23fc39 | 81 | if (kernfs_type(kn) == KERNFS_DIR) |
adc5e8b5 | 82 | kn->parent->dir.subdirs++; |
fd7b9f7b TH |
83 | |
84 | while (*node) { | |
324a56e1 | 85 | struct kernfs_node *pos; |
fd7b9f7b TH |
86 | int result; |
87 | ||
324a56e1 | 88 | pos = rb_to_kn(*node); |
fd7b9f7b | 89 | parent = *node; |
c637b8ac | 90 | result = kernfs_sd_compare(kn, pos); |
fd7b9f7b | 91 | if (result < 0) |
adc5e8b5 | 92 | node = &pos->rb.rb_left; |
fd7b9f7b | 93 | else if (result > 0) |
adc5e8b5 | 94 | node = &pos->rb.rb_right; |
fd7b9f7b TH |
95 | else |
96 | return -EEXIST; | |
97 | } | |
98 | /* add new node and rebalance the tree */ | |
adc5e8b5 TH |
99 | rb_link_node(&kn->rb, parent, node); |
100 | rb_insert_color(&kn->rb, &kn->parent->dir.children); | |
fd7b9f7b TH |
101 | return 0; |
102 | } | |
103 | ||
104 | /** | |
c637b8ac | 105 | * kernfs_unlink_sibling - unlink kernfs_node from sibling rbtree |
324a56e1 | 106 | * @kn: kernfs_node of interest |
fd7b9f7b | 107 | * |
324a56e1 | 108 | * Unlink @kn from its sibling rbtree which starts from |
adc5e8b5 | 109 | * kn->parent->dir.children. |
fd7b9f7b TH |
110 | * |
111 | * Locking: | |
a797bfc3 | 112 | * mutex_lock(kernfs_mutex) |
fd7b9f7b | 113 | */ |
55f6e30d | 114 | static void kernfs_unlink_sibling(struct kernfs_node *kn) |
fd7b9f7b | 115 | { |
df23fc39 | 116 | if (kernfs_type(kn) == KERNFS_DIR) |
adc5e8b5 | 117 | kn->parent->dir.subdirs--; |
fd7b9f7b | 118 | |
adc5e8b5 | 119 | rb_erase(&kn->rb, &kn->parent->dir.children); |
fd7b9f7b TH |
120 | } |
121 | ||
122 | /** | |
c637b8ac | 123 | * kernfs_get_active - get an active reference to kernfs_node |
324a56e1 | 124 | * @kn: kernfs_node to get an active reference to |
fd7b9f7b | 125 | * |
324a56e1 | 126 | * Get an active reference of @kn. This function is noop if @kn |
fd7b9f7b TH |
127 | * is NULL. |
128 | * | |
129 | * RETURNS: | |
324a56e1 | 130 | * Pointer to @kn on success, NULL on failure. |
fd7b9f7b | 131 | */ |
c637b8ac | 132 | struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) |
fd7b9f7b | 133 | { |
324a56e1 | 134 | if (unlikely(!kn)) |
fd7b9f7b TH |
135 | return NULL; |
136 | ||
f4b3e631 GKH |
137 | if (!atomic_inc_unless_negative(&kn->active)) |
138 | return NULL; | |
895a068a | 139 | |
0890147f | 140 | if (kn->flags & KERNFS_LOCKDEP) |
f4b3e631 GKH |
141 | rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_); |
142 | return kn; | |
fd7b9f7b TH |
143 | } |
144 | ||
145 | /** | |
c637b8ac | 146 | * kernfs_put_active - put an active reference to kernfs_node |
324a56e1 | 147 | * @kn: kernfs_node to put an active reference to |
fd7b9f7b | 148 | * |
324a56e1 | 149 | * Put an active reference to @kn. This function is noop if @kn |
fd7b9f7b TH |
150 | * is NULL. |
151 | */ | |
c637b8ac | 152 | void kernfs_put_active(struct kernfs_node *kn) |
fd7b9f7b TH |
153 | { |
154 | int v; | |
155 | ||
324a56e1 | 156 | if (unlikely(!kn)) |
fd7b9f7b TH |
157 | return; |
158 | ||
0890147f | 159 | if (kn->flags & KERNFS_LOCKDEP) |
324a56e1 | 160 | rwsem_release(&kn->dep_map, 1, _RET_IP_); |
adc5e8b5 | 161 | v = atomic_dec_return(&kn->active); |
df23fc39 | 162 | if (likely(v != KN_DEACTIVATED_BIAS)) |
fd7b9f7b TH |
163 | return; |
164 | ||
87da1493 GKH |
165 | /* |
166 | * atomic_dec_return() is a mb(), we'll always see the updated | |
167 | * kn->u.completion. | |
168 | */ | |
169 | complete(kn->u.completion); | |
fd7b9f7b TH |
170 | } |
171 | ||
172 | /** | |
798c75a0 GKH |
173 | * kernfs_deactivate - deactivate kernfs_node |
174 | * @kn: kernfs_node to deactivate | |
fd7b9f7b | 175 | * |
798c75a0 | 176 | * Deny new active references and drain existing ones. |
fd7b9f7b | 177 | */ |
798c75a0 | 178 | static void kernfs_deactivate(struct kernfs_node *kn) |
fd7b9f7b | 179 | { |
87da1493 GKH |
180 | DECLARE_COMPLETION_ONSTACK(wait); |
181 | int v; | |
fd7b9f7b | 182 | |
798c75a0 GKH |
183 | BUG_ON(!(kn->flags & KERNFS_REMOVED)); |
184 | ||
0890147f GKH |
185 | if (!(kernfs_type(kn) & KERNFS_ACTIVE_REF)) |
186 | return; | |
187 | ||
87da1493 | 188 | kn->u.completion = (void *)&wait; |
0890147f | 189 | |
da9846ae TH |
190 | if (kn->flags & KERNFS_LOCKDEP) |
191 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); | |
87da1493 GKH |
192 | /* atomic_add_return() is a mb(), put_active() will always see |
193 | * the updated kn->u.completion. | |
194 | */ | |
195 | v = atomic_add_return(KN_DEACTIVATED_BIAS, &kn->active); | |
ea1c472d | 196 | |
87da1493 | 197 | if (v != KN_DEACTIVATED_BIAS) { |
da9846ae TH |
198 | if (kn->flags & KERNFS_LOCKDEP) |
199 | lock_contended(&kn->dep_map, _RET_IP_); | |
87da1493 GKH |
200 | wait_for_completion(&wait); |
201 | } | |
fd7b9f7b | 202 | |
da9846ae TH |
203 | if (kn->flags & KERNFS_LOCKDEP) { |
204 | lock_acquired(&kn->dep_map, _RET_IP_); | |
205 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
206 | } | |
fd7b9f7b TH |
207 | } |
208 | ||
fd7b9f7b | 209 | /** |
324a56e1 TH |
210 | * kernfs_get - get a reference count on a kernfs_node |
211 | * @kn: the target kernfs_node | |
fd7b9f7b | 212 | */ |
324a56e1 | 213 | void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b | 214 | { |
324a56e1 | 215 | if (kn) { |
adc5e8b5 TH |
216 | WARN_ON(!atomic_read(&kn->count)); |
217 | atomic_inc(&kn->count); | |
fd7b9f7b TH |
218 | } |
219 | } | |
220 | EXPORT_SYMBOL_GPL(kernfs_get); | |
221 | ||
222 | /** | |
324a56e1 TH |
223 | * kernfs_put - put a reference count on a kernfs_node |
224 | * @kn: the target kernfs_node | |
fd7b9f7b | 225 | * |
324a56e1 | 226 | * Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b | 227 | */ |
324a56e1 | 228 | void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b | 229 | { |
324a56e1 | 230 | struct kernfs_node *parent; |
ba7443bc | 231 | struct kernfs_root *root; |
fd7b9f7b | 232 | |
adc5e8b5 | 233 | if (!kn || !atomic_dec_and_test(&kn->count)) |
fd7b9f7b | 234 | return; |
324a56e1 | 235 | root = kernfs_root(kn); |
fd7b9f7b | 236 | repeat: |
798c75a0 | 237 | /* Moving/renaming is always done while holding reference. |
adc5e8b5 | 238 | * kn->parent won't change beneath us. |
fd7b9f7b | 239 | */ |
adc5e8b5 | 240 | parent = kn->parent; |
fd7b9f7b | 241 | |
798c75a0 GKH |
242 | WARN(!(kn->flags & KERNFS_REMOVED), "kernfs: free using entry: %s/%s\n", |
243 | parent ? parent->name : "", kn->name); | |
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 | |
798c75a0 GKH |
285 | /* The kernfs node has been deleted */ |
286 | if (kn->flags & KERNFS_REMOVED) | |
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 | ||
db4aad20 TH |
331 | static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, |
332 | const char *name, umode_t mode, | |
333 | unsigned flags) | |
fd7b9f7b TH |
334 | { |
335 | char *dup_name = NULL; | |
324a56e1 | 336 | struct kernfs_node *kn; |
bc755553 | 337 | int ret; |
fd7b9f7b | 338 | |
2063d608 | 339 | if (!(flags & KERNFS_STATIC_NAME)) { |
fd7b9f7b TH |
340 | name = dup_name = kstrdup(name, GFP_KERNEL); |
341 | if (!name) | |
342 | return NULL; | |
343 | } | |
344 | ||
a797bfc3 | 345 | kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e1 | 346 | if (!kn) |
fd7b9f7b TH |
347 | goto err_out1; |
348 | ||
bc755553 TH |
349 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
350 | if (ret < 0) | |
fd7b9f7b | 351 | goto err_out2; |
adc5e8b5 | 352 | kn->ino = ret; |
fd7b9f7b | 353 | |
adc5e8b5 | 354 | atomic_set(&kn->count, 1); |
798c75a0 | 355 | atomic_set(&kn->active, 0); |
fd7b9f7b | 356 | |
adc5e8b5 TH |
357 | kn->name = name; |
358 | kn->mode = mode; | |
798c75a0 | 359 | kn->flags = flags | KERNFS_REMOVED; |
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 | ||
db4aad20 TH |
370 | struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, |
371 | const char *name, umode_t mode, | |
372 | unsigned flags) | |
373 | { | |
374 | struct kernfs_node *kn; | |
375 | ||
376 | kn = __kernfs_new_node(kernfs_root(parent), name, mode, flags); | |
377 | if (kn) { | |
378 | kernfs_get(parent); | |
379 | kn->parent = parent; | |
380 | } | |
381 | return kn; | |
382 | } | |
383 | ||
7653fe9d GKH |
384 | /** |
385 | * kernfs_addrm_start - prepare for kernfs_node add/remove | |
386 | * @acxt: pointer to kernfs_addrm_cxt to be used | |
387 | * | |
388 | * This function is called when the caller is about to add or remove | |
389 | * kernfs_node. This function acquires kernfs_mutex. @acxt is used | |
390 | * to keep and pass context to other addrm functions. | |
391 | * | |
392 | * LOCKING: | |
393 | * Kernel thread context (may sleep). kernfs_mutex is locked on | |
394 | * return. | |
395 | */ | |
396 | void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt) | |
397 | __acquires(kernfs_mutex) | |
398 | { | |
399 | memset(acxt, 0, sizeof(*acxt)); | |
400 | ||
401 | mutex_lock(&kernfs_mutex); | |
402 | } | |
403 | ||
fd7b9f7b | 404 | /** |
c637b8ac | 405 | * kernfs_add_one - add kernfs_node to parent without warning |
7653fe9d | 406 | * @acxt: addrm context to use |
324a56e1 | 407 | * @kn: kernfs_node to be added |
fd7b9f7b | 408 | * |
db4aad20 TH |
409 | * The caller must already have initialized @kn->parent. This |
410 | * function increments nlink of the parent's inode if @kn is a | |
411 | * directory and link into the children list of the parent. | |
fd7b9f7b | 412 | * |
7653fe9d GKH |
413 | * This function should be called between calls to |
414 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be passed | |
415 | * the same @acxt as passed to kernfs_addrm_start(). | |
416 | * | |
417 | * LOCKING: | |
418 | * Determined by kernfs_addrm_start(). | |
419 | * | |
fd7b9f7b TH |
420 | * RETURNS: |
421 | * 0 on success, -EEXIST if entry with the given name already | |
422 | * exists. | |
423 | */ | |
db4aad20 | 424 | int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn) |
fd7b9f7b | 425 | { |
db4aad20 | 426 | struct kernfs_node *parent = kn->parent; |
7653fe9d | 427 | bool has_ns = kernfs_ns_enabled(parent); |
c525aadd | 428 | struct kernfs_iattrs *ps_iattr; |
fd7b9f7b TH |
429 | int ret; |
430 | ||
7653fe9d GKH |
431 | if (has_ns != (bool)kn->ns) { |
432 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", | |
433 | has_ns ? "required" : "invalid", parent->name, kn->name); | |
434 | return -EINVAL; | |
435 | } | |
fd7b9f7b | 436 | |
df23fc39 | 437 | if (kernfs_type(parent) != KERNFS_DIR) |
7653fe9d | 438 | return -EINVAL; |
fd7b9f7b | 439 | |
798c75a0 GKH |
440 | if (parent->flags & KERNFS_REMOVED) |
441 | return -ENOENT; | |
442 | ||
c637b8ac | 443 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
fd7b9f7b | 444 | |
c637b8ac | 445 | ret = kernfs_link_sibling(kn); |
fd7b9f7b | 446 | if (ret) |
7653fe9d | 447 | return ret; |
fd7b9f7b TH |
448 | |
449 | /* Update timestamps on the parent */ | |
adc5e8b5 | 450 | ps_iattr = parent->iattr; |
fd7b9f7b TH |
451 | if (ps_iattr) { |
452 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
453 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
454 | } | |
455 | ||
456 | /* Mark the entry added into directory tree */ | |
798c75a0 GKH |
457 | kn->flags &= ~KERNFS_REMOVED; |
458 | ||
7653fe9d GKH |
459 | return 0; |
460 | } | |
461 | ||
4f4b1b64 GKH |
462 | /** |
463 | * kernfs_remove_one - remove kernfs_node from parent | |
464 | * @acxt: addrm context to use | |
465 | * @kn: kernfs_node to be removed | |
466 | * | |
467 | * Mark @kn removed and drop nlink of parent inode if @kn is a | |
468 | * directory. @kn is unlinked from the children list. | |
469 | * | |
470 | * This function should be called between calls to | |
471 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be | |
472 | * passed the same @acxt as passed to kernfs_addrm_start(). | |
473 | * | |
474 | * LOCKING: | |
475 | * Determined by kernfs_addrm_start(). | |
476 | */ | |
477 | static void kernfs_remove_one(struct kernfs_addrm_cxt *acxt, | |
478 | struct kernfs_node *kn) | |
479 | { | |
480 | struct kernfs_iattrs *ps_iattr; | |
481 | ||
482 | /* | |
483 | * Removal can be called multiple times on the same node. Only the | |
484 | * first invocation is effective and puts the base ref. | |
485 | */ | |
798c75a0 | 486 | if (kn->flags & KERNFS_REMOVED) |
4f4b1b64 GKH |
487 | return; |
488 | ||
489 | if (kn->parent) { | |
490 | kernfs_unlink_sibling(kn); | |
491 | ||
492 | /* Update timestamps on the parent */ | |
493 | ps_iattr = kn->parent->iattr; | |
494 | if (ps_iattr) { | |
495 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
496 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
497 | } | |
498 | } | |
499 | ||
798c75a0 | 500 | kn->flags |= KERNFS_REMOVED; |
4f4b1b64 GKH |
501 | kn->u.removed_list = acxt->removed; |
502 | acxt->removed = kn; | |
503 | } | |
504 | ||
7653fe9d GKH |
505 | /** |
506 | * kernfs_addrm_finish - finish up kernfs_node add/remove | |
507 | * @acxt: addrm context to finish up | |
508 | * | |
509 | * Finish up kernfs_node add/remove. Resources acquired by | |
510 | * kernfs_addrm_start() are released and removed kernfs_nodes are | |
511 | * cleaned up. | |
512 | * | |
513 | * LOCKING: | |
514 | * kernfs_mutex is released. | |
515 | */ | |
516 | void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt) | |
517 | __releases(kernfs_mutex) | |
518 | { | |
519 | /* release resources acquired by kernfs_addrm_start() */ | |
a797bfc3 | 520 | mutex_unlock(&kernfs_mutex); |
7653fe9d GKH |
521 | |
522 | /* kill removed kernfs_nodes */ | |
523 | while (acxt->removed) { | |
524 | struct kernfs_node *kn = acxt->removed; | |
525 | ||
526 | acxt->removed = kn->u.removed_list; | |
527 | ||
798c75a0 | 528 | kernfs_deactivate(kn); |
55f6e30d | 529 | kernfs_unmap_bin_file(kn); |
7653fe9d GKH |
530 | kernfs_put(kn); |
531 | } | |
fd7b9f7b TH |
532 | } |
533 | ||
534 | /** | |
324a56e1 TH |
535 | * kernfs_find_ns - find kernfs_node with the given name |
536 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
537 | * @name: name to look for |
538 | * @ns: the namespace tag to use | |
539 | * | |
324a56e1 TH |
540 | * Look for kernfs_node with name @name under @parent. Returns pointer to |
541 | * the found kernfs_node on success, %NULL on failure. | |
fd7b9f7b | 542 | */ |
324a56e1 TH |
543 | static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, |
544 | const unsigned char *name, | |
545 | const void *ns) | |
fd7b9f7b | 546 | { |
adc5e8b5 | 547 | struct rb_node *node = parent->dir.children.rb_node; |
ac9bba03 | 548 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
549 | unsigned int hash; |
550 | ||
a797bfc3 | 551 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
552 | |
553 | if (has_ns != (bool)ns) { | |
c637b8ac | 554 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", |
adc5e8b5 | 555 | has_ns ? "required" : "invalid", parent->name, name); |
fd7b9f7b TH |
556 | return NULL; |
557 | } | |
558 | ||
c637b8ac | 559 | hash = kernfs_name_hash(name, ns); |
fd7b9f7b | 560 | while (node) { |
324a56e1 | 561 | struct kernfs_node *kn; |
fd7b9f7b TH |
562 | int result; |
563 | ||
324a56e1 | 564 | kn = rb_to_kn(node); |
c637b8ac | 565 | result = kernfs_name_compare(hash, name, ns, kn); |
fd7b9f7b TH |
566 | if (result < 0) |
567 | node = node->rb_left; | |
568 | else if (result > 0) | |
569 | node = node->rb_right; | |
570 | else | |
324a56e1 | 571 | return kn; |
fd7b9f7b TH |
572 | } |
573 | return NULL; | |
574 | } | |
575 | ||
576 | /** | |
324a56e1 TH |
577 | * kernfs_find_and_get_ns - find and get kernfs_node with the given name |
578 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
579 | * @name: name to look for |
580 | * @ns: the namespace tag to use | |
581 | * | |
324a56e1 | 582 | * Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b | 583 | * if found. This function may sleep and returns pointer to the found |
324a56e1 | 584 | * kernfs_node on success, %NULL on failure. |
fd7b9f7b | 585 | */ |
324a56e1 TH |
586 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
587 | const char *name, const void *ns) | |
fd7b9f7b | 588 | { |
324a56e1 | 589 | struct kernfs_node *kn; |
fd7b9f7b | 590 | |
a797bfc3 | 591 | mutex_lock(&kernfs_mutex); |
324a56e1 TH |
592 | kn = kernfs_find_ns(parent, name, ns); |
593 | kernfs_get(kn); | |
a797bfc3 | 594 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 595 | |
324a56e1 | 596 | return kn; |
fd7b9f7b TH |
597 | } |
598 | EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); | |
599 | ||
ba7443bc TH |
600 | /** |
601 | * kernfs_create_root - create a new kernfs hierarchy | |
80b9bbef | 602 | * @kdops: optional directory syscall operations for the hierarchy |
ba7443bc TH |
603 | * @priv: opaque data associated with the new directory |
604 | * | |
605 | * Returns the root of the new hierarchy on success, ERR_PTR() value on | |
606 | * failure. | |
607 | */ | |
80b9bbef | 608 | struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv) |
ba7443bc TH |
609 | { |
610 | struct kernfs_root *root; | |
324a56e1 | 611 | struct kernfs_node *kn; |
ba7443bc TH |
612 | |
613 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
614 | if (!root) | |
615 | return ERR_PTR(-ENOMEM); | |
616 | ||
bc755553 TH |
617 | ida_init(&root->ino_ida); |
618 | ||
db4aad20 TH |
619 | kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, |
620 | KERNFS_DIR); | |
324a56e1 | 621 | if (!kn) { |
bc755553 | 622 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
623 | kfree(root); |
624 | return ERR_PTR(-ENOMEM); | |
625 | } | |
626 | ||
798c75a0 | 627 | kn->flags &= ~KERNFS_REMOVED; |
324a56e1 | 628 | kn->priv = priv; |
adc5e8b5 | 629 | kn->dir.root = root; |
ba7443bc | 630 | |
80b9bbef | 631 | root->dir_ops = kdops; |
324a56e1 | 632 | root->kn = kn; |
ba7443bc TH |
633 | |
634 | return root; | |
635 | } | |
636 | ||
637 | /** | |
638 | * kernfs_destroy_root - destroy a kernfs hierarchy | |
639 | * @root: root of the hierarchy to destroy | |
640 | * | |
641 | * Destroy the hierarchy anchored at @root by removing all existing | |
642 | * directories and destroying @root. | |
643 | */ | |
644 | void kernfs_destroy_root(struct kernfs_root *root) | |
645 | { | |
324a56e1 | 646 | kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc TH |
647 | } |
648 | ||
fd7b9f7b TH |
649 | /** |
650 | * kernfs_create_dir_ns - create a directory | |
651 | * @parent: parent in which to create a new directory | |
652 | * @name: name of the new directory | |
bb8b9d09 | 653 | * @mode: mode of the new directory |
fd7b9f7b TH |
654 | * @priv: opaque data associated with the new directory |
655 | * @ns: optional namespace tag of the directory | |
656 | * | |
657 | * Returns the created node on success, ERR_PTR() value on failure. | |
658 | */ | |
324a56e1 | 659 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d09 TH |
660 | const char *name, umode_t mode, |
661 | void *priv, const void *ns) | |
fd7b9f7b | 662 | { |
7653fe9d | 663 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 664 | struct kernfs_node *kn; |
fd7b9f7b TH |
665 | int rc; |
666 | ||
667 | /* allocate */ | |
db4aad20 | 668 | kn = kernfs_new_node(parent, name, mode | S_IFDIR, KERNFS_DIR); |
324a56e1 | 669 | if (!kn) |
fd7b9f7b TH |
670 | return ERR_PTR(-ENOMEM); |
671 | ||
adc5e8b5 TH |
672 | kn->dir.root = parent->dir.root; |
673 | kn->ns = ns; | |
324a56e1 | 674 | kn->priv = priv; |
fd7b9f7b TH |
675 | |
676 | /* link in */ | |
798c75a0 | 677 | kernfs_addrm_start(&acxt); |
db4aad20 | 678 | rc = kernfs_add_one(&acxt, kn); |
798c75a0 | 679 | kernfs_addrm_finish(&acxt); |
7653fe9d | 680 | |
fd7b9f7b | 681 | if (!rc) |
324a56e1 | 682 | return kn; |
fd7b9f7b | 683 | |
324a56e1 | 684 | kernfs_put(kn); |
fd7b9f7b TH |
685 | return ERR_PTR(rc); |
686 | } | |
687 | ||
c637b8ac TH |
688 | static struct dentry *kernfs_iop_lookup(struct inode *dir, |
689 | struct dentry *dentry, | |
690 | unsigned int flags) | |
fd7b9f7b | 691 | { |
19bbb926 | 692 | struct dentry *ret; |
324a56e1 TH |
693 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
694 | struct kernfs_node *kn; | |
fd7b9f7b TH |
695 | struct inode *inode; |
696 | const void *ns = NULL; | |
697 | ||
a797bfc3 | 698 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 699 | |
324a56e1 | 700 | if (kernfs_ns_enabled(parent)) |
c525aadd | 701 | ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b | 702 | |
324a56e1 | 703 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
704 | |
705 | /* no such entry */ | |
324a56e1 | 706 | if (!kn) { |
19bbb926 | 707 | ret = NULL; |
fd7b9f7b TH |
708 | goto out_unlock; |
709 | } | |
324a56e1 TH |
710 | kernfs_get(kn); |
711 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
712 | |
713 | /* attach dentry and inode */ | |
c637b8ac | 714 | inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
715 | if (!inode) { |
716 | ret = ERR_PTR(-ENOMEM); | |
717 | goto out_unlock; | |
718 | } | |
719 | ||
720 | /* instantiate and hash dentry */ | |
721 | ret = d_materialise_unique(dentry, inode); | |
722 | out_unlock: | |
a797bfc3 | 723 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
724 | return ret; |
725 | } | |
726 | ||
80b9bbef TH |
727 | static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, |
728 | umode_t mode) | |
729 | { | |
730 | struct kernfs_node *parent = dir->i_private; | |
731 | struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops; | |
732 | ||
733 | if (!kdops || !kdops->mkdir) | |
734 | return -EPERM; | |
735 | ||
736 | return kdops->mkdir(parent, dentry->d_name.name, mode); | |
737 | } | |
738 | ||
739 | static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) | |
740 | { | |
741 | struct kernfs_node *kn = dentry->d_fsdata; | |
742 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
743 | ||
744 | if (!kdops || !kdops->rmdir) | |
745 | return -EPERM; | |
746 | ||
747 | return kdops->rmdir(kn); | |
748 | } | |
749 | ||
750 | static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, | |
751 | struct inode *new_dir, struct dentry *new_dentry) | |
752 | { | |
753 | struct kernfs_node *kn = old_dentry->d_fsdata; | |
754 | struct kernfs_node *new_parent = new_dir->i_private; | |
755 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
756 | ||
757 | if (!kdops || !kdops->rename) | |
758 | return -EPERM; | |
759 | ||
760 | return kdops->rename(kn, new_parent, new_dentry->d_name.name); | |
761 | } | |
762 | ||
a797bfc3 | 763 | const struct inode_operations kernfs_dir_iops = { |
c637b8ac TH |
764 | .lookup = kernfs_iop_lookup, |
765 | .permission = kernfs_iop_permission, | |
766 | .setattr = kernfs_iop_setattr, | |
767 | .getattr = kernfs_iop_getattr, | |
768 | .setxattr = kernfs_iop_setxattr, | |
769 | .removexattr = kernfs_iop_removexattr, | |
770 | .getxattr = kernfs_iop_getxattr, | |
771 | .listxattr = kernfs_iop_listxattr, | |
80b9bbef TH |
772 | |
773 | .mkdir = kernfs_iop_mkdir, | |
774 | .rmdir = kernfs_iop_rmdir, | |
775 | .rename = kernfs_iop_rename, | |
fd7b9f7b TH |
776 | }; |
777 | ||
c637b8ac | 778 | static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 779 | { |
324a56e1 | 780 | struct kernfs_node *last; |
fd7b9f7b TH |
781 | |
782 | while (true) { | |
783 | struct rb_node *rbn; | |
784 | ||
785 | last = pos; | |
786 | ||
df23fc39 | 787 | if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b TH |
788 | break; |
789 | ||
adc5e8b5 | 790 | rbn = rb_first(&pos->dir.children); |
fd7b9f7b TH |
791 | if (!rbn) |
792 | break; | |
793 | ||
324a56e1 | 794 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
795 | } |
796 | ||
797 | return last; | |
798 | } | |
799 | ||
800 | /** | |
c637b8ac | 801 | * kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b | 802 | * @pos: the current position (%NULL to initiate traversal) |
324a56e1 | 803 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
804 | * |
805 | * Find the next descendant to visit for post-order traversal of @root's | |
806 | * descendants. @root is included in the iteration and the last node to be | |
807 | * visited. | |
808 | */ | |
c637b8ac TH |
809 | static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, |
810 | struct kernfs_node *root) | |
fd7b9f7b TH |
811 | { |
812 | struct rb_node *rbn; | |
813 | ||
a797bfc3 | 814 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
815 | |
816 | /* if first iteration, visit leftmost descendant which may be root */ | |
817 | if (!pos) | |
c637b8ac | 818 | return kernfs_leftmost_descendant(root); |
fd7b9f7b TH |
819 | |
820 | /* if we visited @root, we're done */ | |
821 | if (pos == root) | |
822 | return NULL; | |
823 | ||
824 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
adc5e8b5 | 825 | rbn = rb_next(&pos->rb); |
fd7b9f7b | 826 | if (rbn) |
c637b8ac | 827 | return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
828 | |
829 | /* no sibling left, visit parent */ | |
adc5e8b5 | 830 | return pos->parent; |
fd7b9f7b TH |
831 | } |
832 | ||
7653fe9d GKH |
833 | static void __kernfs_remove(struct kernfs_addrm_cxt *acxt, |
834 | struct kernfs_node *kn) | |
fd7b9f7b | 835 | { |
4f4b1b64 | 836 | struct kernfs_node *pos, *next; |
fd7b9f7b | 837 | |
ce9b499c GKH |
838 | if (!kn) |
839 | return; | |
840 | ||
c637b8ac | 841 | pr_debug("kernfs %s: removing\n", kn->name); |
fd7b9f7b | 842 | |
4f4b1b64 | 843 | next = NULL; |
fd7b9f7b | 844 | do { |
4f4b1b64 GKH |
845 | pos = next; |
846 | next = kernfs_next_descendant_post(pos, kn); | |
847 | if (pos) | |
848 | kernfs_remove_one(acxt, pos); | |
849 | } while (next); | |
fd7b9f7b TH |
850 | } |
851 | ||
852 | /** | |
324a56e1 TH |
853 | * kernfs_remove - remove a kernfs_node recursively |
854 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 855 | * |
324a56e1 | 856 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 857 | */ |
324a56e1 | 858 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 859 | { |
7653fe9d GKH |
860 | struct kernfs_addrm_cxt acxt; |
861 | ||
862 | kernfs_addrm_start(&acxt); | |
863 | __kernfs_remove(&acxt, kn); | |
864 | kernfs_addrm_finish(&acxt); | |
fd7b9f7b TH |
865 | } |
866 | ||
867 | /** | |
324a56e1 TH |
868 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
869 | * @parent: parent of the target | |
870 | * @name: name of the kernfs_node to remove | |
871 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 872 | * |
324a56e1 TH |
873 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
874 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 875 | */ |
324a56e1 | 876 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
877 | const void *ns) |
878 | { | |
7653fe9d | 879 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 880 | struct kernfs_node *kn; |
fd7b9f7b | 881 | |
324a56e1 | 882 | if (!parent) { |
c637b8ac | 883 | WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n", |
fd7b9f7b TH |
884 | name); |
885 | return -ENOENT; | |
886 | } | |
887 | ||
7653fe9d | 888 | kernfs_addrm_start(&acxt); |
fd7b9f7b | 889 | |
324a56e1 TH |
890 | kn = kernfs_find_ns(parent, name, ns); |
891 | if (kn) | |
7653fe9d | 892 | __kernfs_remove(&acxt, kn); |
fd7b9f7b | 893 | |
7653fe9d | 894 | kernfs_addrm_finish(&acxt); |
fd7b9f7b | 895 | |
324a56e1 | 896 | if (kn) |
fd7b9f7b TH |
897 | return 0; |
898 | else | |
899 | return -ENOENT; | |
900 | } | |
901 | ||
902 | /** | |
903 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 904 | * @kn: target node |
fd7b9f7b TH |
905 | * @new_parent: new parent to put @sd under |
906 | * @new_name: new name | |
907 | * @new_ns: new namespace tag | |
908 | */ | |
324a56e1 | 909 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
910 | const char *new_name, const void *new_ns) |
911 | { | |
912 | int error; | |
913 | ||
798c75a0 GKH |
914 | mutex_lock(&kernfs_mutex); |
915 | ||
d0ae3d43 | 916 | error = -ENOENT; |
798c75a0 | 917 | if ((kn->flags | new_parent->flags) & KERNFS_REMOVED) |
d0ae3d43 TH |
918 | goto out; |
919 | ||
fd7b9f7b | 920 | error = 0; |
adc5e8b5 TH |
921 | if ((kn->parent == new_parent) && (kn->ns == new_ns) && |
922 | (strcmp(kn->name, new_name) == 0)) | |
798c75a0 | 923 | goto out; /* nothing to rename */ |
fd7b9f7b TH |
924 | |
925 | error = -EEXIST; | |
926 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
798c75a0 | 927 | goto out; |
fd7b9f7b | 928 | |
324a56e1 | 929 | /* rename kernfs_node */ |
adc5e8b5 | 930 | if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b TH |
931 | error = -ENOMEM; |
932 | new_name = kstrdup(new_name, GFP_KERNEL); | |
933 | if (!new_name) | |
798c75a0 | 934 | goto out; |
fd7b9f7b | 935 | |
47a52e91 TH |
936 | if (kn->flags & KERNFS_STATIC_NAME) |
937 | kn->flags &= ~KERNFS_STATIC_NAME; | |
938 | else | |
939 | kfree(kn->name); | |
940 | ||
adc5e8b5 | 941 | kn->name = new_name; |
fd7b9f7b TH |
942 | } |
943 | ||
944 | /* | |
945 | * Move to the appropriate place in the appropriate directories rbtree. | |
946 | */ | |
c637b8ac | 947 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 948 | kernfs_get(new_parent); |
adc5e8b5 TH |
949 | kernfs_put(kn->parent); |
950 | kn->ns = new_ns; | |
c637b8ac | 951 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 952 | kn->parent = new_parent; |
c637b8ac | 953 | kernfs_link_sibling(kn); |
fd7b9f7b TH |
954 | |
955 | error = 0; | |
798c75a0 | 956 | out: |
a797bfc3 | 957 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
958 | return error; |
959 | } | |
960 | ||
fd7b9f7b | 961 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 962 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 963 | { |
adc5e8b5 | 964 | return (kn->mode >> 12) & 15; |
fd7b9f7b TH |
965 | } |
966 | ||
c637b8ac | 967 | static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b TH |
968 | { |
969 | kernfs_put(filp->private_data); | |
970 | return 0; | |
971 | } | |
972 | ||
c637b8ac | 973 | static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e1 | 974 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b TH |
975 | { |
976 | if (pos) { | |
798c75a0 GKH |
977 | int valid = !(pos->flags & KERNFS_REMOVED) && |
978 | pos->parent == parent && hash == pos->hash; | |
fd7b9f7b TH |
979 | kernfs_put(pos); |
980 | if (!valid) | |
981 | pos = NULL; | |
982 | } | |
983 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
adc5e8b5 | 984 | struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b | 985 | while (node) { |
324a56e1 | 986 | pos = rb_to_kn(node); |
fd7b9f7b | 987 | |
adc5e8b5 | 988 | if (hash < pos->hash) |
fd7b9f7b | 989 | node = node->rb_left; |
adc5e8b5 | 990 | else if (hash > pos->hash) |
fd7b9f7b TH |
991 | node = node->rb_right; |
992 | else | |
993 | break; | |
994 | } | |
995 | } | |
996 | /* Skip over entries in the wrong namespace */ | |
adc5e8b5 TH |
997 | while (pos && pos->ns != ns) { |
998 | struct rb_node *node = rb_next(&pos->rb); | |
fd7b9f7b TH |
999 | if (!node) |
1000 | pos = NULL; | |
1001 | else | |
324a56e1 | 1002 | pos = rb_to_kn(node); |
fd7b9f7b TH |
1003 | } |
1004 | return pos; | |
1005 | } | |
1006 | ||
c637b8ac | 1007 | static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e1 | 1008 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b | 1009 | { |
c637b8ac | 1010 | pos = kernfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
1011 | if (pos) |
1012 | do { | |
adc5e8b5 | 1013 | struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b TH |
1014 | if (!node) |
1015 | pos = NULL; | |
1016 | else | |
324a56e1 | 1017 | pos = rb_to_kn(node); |
adc5e8b5 | 1018 | } while (pos && pos->ns != ns); |
fd7b9f7b TH |
1019 | return pos; |
1020 | } | |
1021 | ||
c637b8ac | 1022 | static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b TH |
1023 | { |
1024 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
1025 | struct kernfs_node *parent = dentry->d_fsdata; |
1026 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
1027 | const void *ns = NULL; |
1028 | ||
1029 | if (!dir_emit_dots(file, ctx)) | |
1030 | return 0; | |
a797bfc3 | 1031 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1032 | |
324a56e1 | 1033 | if (kernfs_ns_enabled(parent)) |
c525aadd | 1034 | ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b | 1035 | |
c637b8ac | 1036 | for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 1037 | pos; |
c637b8ac | 1038 | pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b5 | 1039 | const char *name = pos->name; |
fd7b9f7b TH |
1040 | unsigned int type = dt_type(pos); |
1041 | int len = strlen(name); | |
adc5e8b5 | 1042 | ino_t ino = pos->ino; |
fd7b9f7b | 1043 | |
adc5e8b5 | 1044 | ctx->pos = pos->hash; |
fd7b9f7b TH |
1045 | file->private_data = pos; |
1046 | kernfs_get(pos); | |
1047 | ||
a797bfc3 | 1048 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1049 | if (!dir_emit(ctx, name, len, ino, type)) |
1050 | return 0; | |
a797bfc3 | 1051 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1052 | } |
a797bfc3 | 1053 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1054 | file->private_data = NULL; |
1055 | ctx->pos = INT_MAX; | |
1056 | return 0; | |
1057 | } | |
1058 | ||
c637b8ac TH |
1059 | static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset, |
1060 | int whence) | |
fd7b9f7b TH |
1061 | { |
1062 | struct inode *inode = file_inode(file); | |
1063 | loff_t ret; | |
1064 | ||
1065 | mutex_lock(&inode->i_mutex); | |
1066 | ret = generic_file_llseek(file, offset, whence); | |
1067 | mutex_unlock(&inode->i_mutex); | |
1068 | ||
1069 | return ret; | |
1070 | } | |
1071 | ||
a797bfc3 | 1072 | const struct file_operations kernfs_dir_fops = { |
fd7b9f7b | 1073 | .read = generic_read_dir, |
c637b8ac TH |
1074 | .iterate = kernfs_fop_readdir, |
1075 | .release = kernfs_dir_fop_release, | |
1076 | .llseek = kernfs_dir_fop_llseek, | |
fd7b9f7b | 1077 | }; |