Commit | Line | Data |
---|---|---|
b8441ed2 TH |
1 | /* |
2 | * fs/kernfs/dir.c - kernfs directory implementation | |
3 | * | |
4 | * Copyright (c) 2001-3 Patrick Mochel | |
5 | * Copyright (c) 2007 SUSE Linux Products GmbH | |
6 | * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org> | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | */ | |
fd7b9f7b | 10 | |
abd54f02 | 11 | #include <linux/sched.h> |
fd7b9f7b TH |
12 | #include <linux/fs.h> |
13 | #include <linux/namei.h> | |
14 | #include <linux/idr.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/security.h> | |
17 | #include <linux/hash.h> | |
18 | ||
19 | #include "kernfs-internal.h" | |
20 | ||
a797bfc3 | 21 | DEFINE_MUTEX(kernfs_mutex); |
fd7b9f7b | 22 | |
adc5e8b5 | 23 | #define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb) |
fd7b9f7b | 24 | |
fd7b9f7b | 25 | /** |
c637b8ac | 26 | * kernfs_name_hash |
fd7b9f7b TH |
27 | * @name: Null terminated string to hash |
28 | * @ns: Namespace tag to hash | |
29 | * | |
30 | * Returns 31 bit hash of ns + name (so it fits in an off_t ) | |
31 | */ | |
c637b8ac | 32 | static unsigned int kernfs_name_hash(const char *name, const void *ns) |
fd7b9f7b TH |
33 | { |
34 | unsigned long hash = init_name_hash(); | |
35 | unsigned int len = strlen(name); | |
36 | while (len--) | |
37 | hash = partial_name_hash(*name++, hash); | |
38 | hash = (end_name_hash(hash) ^ hash_ptr((void *)ns, 31)); | |
39 | hash &= 0x7fffffffU; | |
40 | /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */ | |
41 | if (hash < 1) | |
42 | hash += 2; | |
43 | if (hash >= INT_MAX) | |
44 | hash = INT_MAX - 1; | |
45 | return hash; | |
46 | } | |
47 | ||
c637b8ac TH |
48 | static int kernfs_name_compare(unsigned int hash, const char *name, |
49 | const void *ns, const struct kernfs_node *kn) | |
fd7b9f7b | 50 | { |
adc5e8b5 TH |
51 | if (hash != kn->hash) |
52 | return hash - kn->hash; | |
53 | if (ns != kn->ns) | |
54 | return ns - kn->ns; | |
55 | return strcmp(name, kn->name); | |
fd7b9f7b TH |
56 | } |
57 | ||
c637b8ac TH |
58 | static int kernfs_sd_compare(const struct kernfs_node *left, |
59 | const struct kernfs_node *right) | |
fd7b9f7b | 60 | { |
c637b8ac | 61 | return kernfs_name_compare(left->hash, left->name, left->ns, right); |
fd7b9f7b TH |
62 | } |
63 | ||
64 | /** | |
c637b8ac | 65 | * kernfs_link_sibling - link kernfs_node into sibling rbtree |
324a56e1 | 66 | * @kn: kernfs_node of interest |
fd7b9f7b | 67 | * |
324a56e1 | 68 | * Link @kn into its sibling rbtree which starts from |
adc5e8b5 | 69 | * @kn->parent->dir.children. |
fd7b9f7b TH |
70 | * |
71 | * Locking: | |
a797bfc3 | 72 | * mutex_lock(kernfs_mutex) |
fd7b9f7b TH |
73 | * |
74 | * RETURNS: | |
75 | * 0 on susccess -EEXIST on failure. | |
76 | */ | |
c637b8ac | 77 | static int kernfs_link_sibling(struct kernfs_node *kn) |
fd7b9f7b | 78 | { |
adc5e8b5 | 79 | struct rb_node **node = &kn->parent->dir.children.rb_node; |
fd7b9f7b TH |
80 | struct rb_node *parent = NULL; |
81 | ||
df23fc39 | 82 | if (kernfs_type(kn) == KERNFS_DIR) |
adc5e8b5 | 83 | kn->parent->dir.subdirs++; |
fd7b9f7b TH |
84 | |
85 | while (*node) { | |
324a56e1 | 86 | struct kernfs_node *pos; |
fd7b9f7b TH |
87 | int result; |
88 | ||
324a56e1 | 89 | pos = rb_to_kn(*node); |
fd7b9f7b | 90 | parent = *node; |
c637b8ac | 91 | result = kernfs_sd_compare(kn, pos); |
fd7b9f7b | 92 | if (result < 0) |
adc5e8b5 | 93 | node = &pos->rb.rb_left; |
fd7b9f7b | 94 | else if (result > 0) |
adc5e8b5 | 95 | node = &pos->rb.rb_right; |
fd7b9f7b TH |
96 | else |
97 | return -EEXIST; | |
98 | } | |
99 | /* add new node and rebalance the tree */ | |
adc5e8b5 TH |
100 | rb_link_node(&kn->rb, parent, node); |
101 | rb_insert_color(&kn->rb, &kn->parent->dir.children); | |
fd7b9f7b TH |
102 | return 0; |
103 | } | |
104 | ||
105 | /** | |
c637b8ac | 106 | * kernfs_unlink_sibling - unlink kernfs_node from sibling rbtree |
324a56e1 | 107 | * @kn: kernfs_node of interest |
fd7b9f7b | 108 | * |
324a56e1 | 109 | * Unlink @kn from its sibling rbtree which starts from |
adc5e8b5 | 110 | * kn->parent->dir.children. |
fd7b9f7b TH |
111 | * |
112 | * Locking: | |
a797bfc3 | 113 | * mutex_lock(kernfs_mutex) |
fd7b9f7b | 114 | */ |
55f6e30d | 115 | static void kernfs_unlink_sibling(struct kernfs_node *kn) |
fd7b9f7b | 116 | { |
df23fc39 | 117 | if (kernfs_type(kn) == KERNFS_DIR) |
adc5e8b5 | 118 | kn->parent->dir.subdirs--; |
fd7b9f7b | 119 | |
adc5e8b5 | 120 | rb_erase(&kn->rb, &kn->parent->dir.children); |
fd7b9f7b TH |
121 | } |
122 | ||
123 | /** | |
c637b8ac | 124 | * kernfs_get_active - get an active reference to kernfs_node |
324a56e1 | 125 | * @kn: kernfs_node to get an active reference to |
fd7b9f7b | 126 | * |
324a56e1 | 127 | * Get an active reference of @kn. This function is noop if @kn |
fd7b9f7b TH |
128 | * is NULL. |
129 | * | |
130 | * RETURNS: | |
324a56e1 | 131 | * Pointer to @kn on success, NULL on failure. |
fd7b9f7b | 132 | */ |
c637b8ac | 133 | struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) |
fd7b9f7b | 134 | { |
324a56e1 | 135 | if (unlikely(!kn)) |
fd7b9f7b TH |
136 | return NULL; |
137 | ||
f4b3e631 GKH |
138 | if (!atomic_inc_unless_negative(&kn->active)) |
139 | return NULL; | |
895a068a | 140 | |
0890147f | 141 | if (kn->flags & KERNFS_LOCKDEP) |
f4b3e631 GKH |
142 | rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_); |
143 | return kn; | |
fd7b9f7b TH |
144 | } |
145 | ||
146 | /** | |
c637b8ac | 147 | * kernfs_put_active - put an active reference to kernfs_node |
324a56e1 | 148 | * @kn: kernfs_node to put an active reference to |
fd7b9f7b | 149 | * |
324a56e1 | 150 | * Put an active reference to @kn. This function is noop if @kn |
fd7b9f7b TH |
151 | * is NULL. |
152 | */ | |
c637b8ac | 153 | void kernfs_put_active(struct kernfs_node *kn) |
fd7b9f7b | 154 | { |
abd54f02 | 155 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b TH |
156 | int v; |
157 | ||
324a56e1 | 158 | if (unlikely(!kn)) |
fd7b9f7b TH |
159 | return; |
160 | ||
0890147f | 161 | if (kn->flags & KERNFS_LOCKDEP) |
324a56e1 | 162 | rwsem_release(&kn->dep_map, 1, _RET_IP_); |
adc5e8b5 | 163 | v = atomic_dec_return(&kn->active); |
df23fc39 | 164 | if (likely(v != KN_DEACTIVATED_BIAS)) |
fd7b9f7b TH |
165 | return; |
166 | ||
abd54f02 | 167 | wake_up_all(&root->deactivate_waitq); |
fd7b9f7b TH |
168 | } |
169 | ||
170 | /** | |
798c75a0 GKH |
171 | * kernfs_deactivate - deactivate kernfs_node |
172 | * @kn: kernfs_node to deactivate | |
fd7b9f7b | 173 | * |
798c75a0 | 174 | * Deny new active references and drain existing ones. |
fd7b9f7b | 175 | */ |
798c75a0 | 176 | static void kernfs_deactivate(struct kernfs_node *kn) |
fd7b9f7b | 177 | { |
abd54f02 | 178 | struct kernfs_root *root = kernfs_root(kn); |
fd7b9f7b | 179 | |
798c75a0 GKH |
180 | BUG_ON(!(kn->flags & KERNFS_REMOVED)); |
181 | ||
0890147f GKH |
182 | if (!(kernfs_type(kn) & KERNFS_ACTIVE_REF)) |
183 | return; | |
184 | ||
a6607930 TH |
185 | if (kn->flags & KERNFS_LOCKDEP) |
186 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); | |
ea1c472d | 187 | |
abd54f02 TH |
188 | atomic_add(KN_DEACTIVATED_BIAS, &kn->active); |
189 | ||
190 | if ((kn->flags & KERNFS_LOCKDEP) && | |
191 | atomic_read(&kn->active) != KN_DEACTIVATED_BIAS) | |
192 | lock_contended(&kn->dep_map, _RET_IP_); | |
193 | ||
194 | wait_event(root->deactivate_waitq, | |
195 | atomic_read(&kn->active) == KN_DEACTIVATED_BIAS); | |
fd7b9f7b | 196 | |
a6607930 TH |
197 | if (kn->flags & KERNFS_LOCKDEP) { |
198 | lock_acquired(&kn->dep_map, _RET_IP_); | |
199 | rwsem_release(&kn->dep_map, 1, _RET_IP_); | |
200 | } | |
fd7b9f7b TH |
201 | } |
202 | ||
fd7b9f7b | 203 | /** |
324a56e1 TH |
204 | * kernfs_get - get a reference count on a kernfs_node |
205 | * @kn: the target kernfs_node | |
fd7b9f7b | 206 | */ |
324a56e1 | 207 | void kernfs_get(struct kernfs_node *kn) |
fd7b9f7b | 208 | { |
324a56e1 | 209 | if (kn) { |
adc5e8b5 TH |
210 | WARN_ON(!atomic_read(&kn->count)); |
211 | atomic_inc(&kn->count); | |
fd7b9f7b TH |
212 | } |
213 | } | |
214 | EXPORT_SYMBOL_GPL(kernfs_get); | |
215 | ||
216 | /** | |
324a56e1 TH |
217 | * kernfs_put - put a reference count on a kernfs_node |
218 | * @kn: the target kernfs_node | |
fd7b9f7b | 219 | * |
324a56e1 | 220 | * Put a reference count of @kn and destroy it if it reached zero. |
fd7b9f7b | 221 | */ |
324a56e1 | 222 | void kernfs_put(struct kernfs_node *kn) |
fd7b9f7b | 223 | { |
324a56e1 | 224 | struct kernfs_node *parent; |
ba7443bc | 225 | struct kernfs_root *root; |
fd7b9f7b | 226 | |
adc5e8b5 | 227 | if (!kn || !atomic_dec_and_test(&kn->count)) |
fd7b9f7b | 228 | return; |
324a56e1 | 229 | root = kernfs_root(kn); |
fd7b9f7b | 230 | repeat: |
798c75a0 | 231 | /* Moving/renaming is always done while holding reference. |
adc5e8b5 | 232 | * kn->parent won't change beneath us. |
fd7b9f7b | 233 | */ |
adc5e8b5 | 234 | parent = kn->parent; |
fd7b9f7b | 235 | |
798c75a0 GKH |
236 | WARN(!(kn->flags & KERNFS_REMOVED), "kernfs: free using entry: %s/%s\n", |
237 | parent ? parent->name : "", kn->name); | |
324a56e1 | 238 | |
df23fc39 | 239 | if (kernfs_type(kn) == KERNFS_LINK) |
adc5e8b5 | 240 | kernfs_put(kn->symlink.target_kn); |
2063d608 | 241 | if (!(kn->flags & KERNFS_STATIC_NAME)) |
adc5e8b5 TH |
242 | kfree(kn->name); |
243 | if (kn->iattr) { | |
244 | if (kn->iattr->ia_secdata) | |
245 | security_release_secctx(kn->iattr->ia_secdata, | |
246 | kn->iattr->ia_secdata_len); | |
247 | simple_xattrs_free(&kn->iattr->xattrs); | |
2322392b | 248 | } |
adc5e8b5 TH |
249 | kfree(kn->iattr); |
250 | ida_simple_remove(&root->ino_ida, kn->ino); | |
a797bfc3 | 251 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b | 252 | |
324a56e1 TH |
253 | kn = parent; |
254 | if (kn) { | |
adc5e8b5 | 255 | if (atomic_dec_and_test(&kn->count)) |
ba7443bc TH |
256 | goto repeat; |
257 | } else { | |
324a56e1 | 258 | /* just released the root kn, free @root too */ |
bc755553 | 259 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
260 | kfree(root); |
261 | } | |
fd7b9f7b TH |
262 | } |
263 | EXPORT_SYMBOL_GPL(kernfs_put); | |
264 | ||
c637b8ac | 265 | static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags) |
fd7b9f7b | 266 | { |
324a56e1 | 267 | struct kernfs_node *kn; |
fd7b9f7b TH |
268 | |
269 | if (flags & LOOKUP_RCU) | |
270 | return -ECHILD; | |
271 | ||
19bbb926 TH |
272 | /* Always perform fresh lookup for negatives */ |
273 | if (!dentry->d_inode) | |
274 | goto out_bad_unlocked; | |
275 | ||
324a56e1 | 276 | kn = dentry->d_fsdata; |
a797bfc3 | 277 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 278 | |
798c75a0 GKH |
279 | /* The kernfs node has been deleted */ |
280 | if (kn->flags & KERNFS_REMOVED) | |
fd7b9f7b TH |
281 | goto out_bad; |
282 | ||
c637b8ac | 283 | /* The kernfs node has been moved? */ |
adc5e8b5 | 284 | if (dentry->d_parent->d_fsdata != kn->parent) |
fd7b9f7b TH |
285 | goto out_bad; |
286 | ||
c637b8ac | 287 | /* The kernfs node has been renamed */ |
adc5e8b5 | 288 | if (strcmp(dentry->d_name.name, kn->name) != 0) |
fd7b9f7b TH |
289 | goto out_bad; |
290 | ||
c637b8ac | 291 | /* The kernfs node has been moved to a different namespace */ |
adc5e8b5 | 292 | if (kn->parent && kernfs_ns_enabled(kn->parent) && |
c525aadd | 293 | kernfs_info(dentry->d_sb)->ns != kn->ns) |
fd7b9f7b TH |
294 | goto out_bad; |
295 | ||
a797bfc3 | 296 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
297 | out_valid: |
298 | return 1; | |
299 | out_bad: | |
a797bfc3 | 300 | mutex_unlock(&kernfs_mutex); |
19bbb926 TH |
301 | out_bad_unlocked: |
302 | /* | |
303 | * @dentry doesn't match the underlying kernfs node, drop the | |
304 | * dentry and force lookup. If we have submounts we must allow the | |
305 | * vfs caches to lie about the state of the filesystem to prevent | |
306 | * leaks and other nasty things, so use check_submounts_and_drop() | |
307 | * instead of d_drop(). | |
fd7b9f7b TH |
308 | */ |
309 | if (check_submounts_and_drop(dentry) != 0) | |
310 | goto out_valid; | |
311 | ||
312 | return 0; | |
313 | } | |
314 | ||
c637b8ac | 315 | static void kernfs_dop_release(struct dentry *dentry) |
fd7b9f7b TH |
316 | { |
317 | kernfs_put(dentry->d_fsdata); | |
318 | } | |
319 | ||
a797bfc3 | 320 | const struct dentry_operations kernfs_dops = { |
c637b8ac | 321 | .d_revalidate = kernfs_dop_revalidate, |
c637b8ac | 322 | .d_release = kernfs_dop_release, |
fd7b9f7b TH |
323 | }; |
324 | ||
db4aad20 TH |
325 | static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, |
326 | const char *name, umode_t mode, | |
327 | unsigned flags) | |
fd7b9f7b TH |
328 | { |
329 | char *dup_name = NULL; | |
324a56e1 | 330 | struct kernfs_node *kn; |
bc755553 | 331 | int ret; |
fd7b9f7b | 332 | |
2063d608 | 333 | if (!(flags & KERNFS_STATIC_NAME)) { |
fd7b9f7b TH |
334 | name = dup_name = kstrdup(name, GFP_KERNEL); |
335 | if (!name) | |
336 | return NULL; | |
337 | } | |
338 | ||
a797bfc3 | 339 | kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e1 | 340 | if (!kn) |
fd7b9f7b TH |
341 | goto err_out1; |
342 | ||
bc755553 TH |
343 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
344 | if (ret < 0) | |
fd7b9f7b | 345 | goto err_out2; |
adc5e8b5 | 346 | kn->ino = ret; |
fd7b9f7b | 347 | |
adc5e8b5 | 348 | atomic_set(&kn->count, 1); |
798c75a0 | 349 | atomic_set(&kn->active, 0); |
fd7b9f7b | 350 | |
adc5e8b5 TH |
351 | kn->name = name; |
352 | kn->mode = mode; | |
798c75a0 | 353 | kn->flags = flags | KERNFS_REMOVED; |
fd7b9f7b | 354 | |
324a56e1 | 355 | return kn; |
fd7b9f7b TH |
356 | |
357 | err_out2: | |
a797bfc3 | 358 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b TH |
359 | err_out1: |
360 | kfree(dup_name); | |
361 | return NULL; | |
362 | } | |
363 | ||
db4aad20 TH |
364 | struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, |
365 | const char *name, umode_t mode, | |
366 | unsigned flags) | |
367 | { | |
368 | struct kernfs_node *kn; | |
369 | ||
370 | kn = __kernfs_new_node(kernfs_root(parent), name, mode, flags); | |
371 | if (kn) { | |
372 | kernfs_get(parent); | |
373 | kn->parent = parent; | |
374 | } | |
375 | return kn; | |
376 | } | |
377 | ||
7653fe9d GKH |
378 | /** |
379 | * kernfs_addrm_start - prepare for kernfs_node add/remove | |
380 | * @acxt: pointer to kernfs_addrm_cxt to be used | |
381 | * | |
382 | * This function is called when the caller is about to add or remove | |
383 | * kernfs_node. This function acquires kernfs_mutex. @acxt is used | |
384 | * to keep and pass context to other addrm functions. | |
385 | * | |
386 | * LOCKING: | |
387 | * Kernel thread context (may sleep). kernfs_mutex is locked on | |
388 | * return. | |
389 | */ | |
390 | void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt) | |
391 | __acquires(kernfs_mutex) | |
392 | { | |
393 | memset(acxt, 0, sizeof(*acxt)); | |
394 | ||
395 | mutex_lock(&kernfs_mutex); | |
396 | } | |
397 | ||
fd7b9f7b | 398 | /** |
c637b8ac | 399 | * kernfs_add_one - add kernfs_node to parent without warning |
7653fe9d | 400 | * @acxt: addrm context to use |
324a56e1 | 401 | * @kn: kernfs_node to be added |
fd7b9f7b | 402 | * |
db4aad20 TH |
403 | * The caller must already have initialized @kn->parent. This |
404 | * function increments nlink of the parent's inode if @kn is a | |
405 | * directory and link into the children list of the parent. | |
fd7b9f7b | 406 | * |
7653fe9d GKH |
407 | * This function should be called between calls to |
408 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be passed | |
409 | * the same @acxt as passed to kernfs_addrm_start(). | |
410 | * | |
411 | * LOCKING: | |
412 | * Determined by kernfs_addrm_start(). | |
413 | * | |
fd7b9f7b TH |
414 | * RETURNS: |
415 | * 0 on success, -EEXIST if entry with the given name already | |
416 | * exists. | |
417 | */ | |
db4aad20 | 418 | int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn) |
fd7b9f7b | 419 | { |
db4aad20 | 420 | struct kernfs_node *parent = kn->parent; |
7653fe9d | 421 | bool has_ns = kernfs_ns_enabled(parent); |
c525aadd | 422 | struct kernfs_iattrs *ps_iattr; |
fd7b9f7b TH |
423 | int ret; |
424 | ||
7653fe9d GKH |
425 | if (has_ns != (bool)kn->ns) { |
426 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", | |
427 | has_ns ? "required" : "invalid", parent->name, kn->name); | |
428 | return -EINVAL; | |
429 | } | |
fd7b9f7b | 430 | |
df23fc39 | 431 | if (kernfs_type(parent) != KERNFS_DIR) |
7653fe9d | 432 | return -EINVAL; |
fd7b9f7b | 433 | |
798c75a0 GKH |
434 | if (parent->flags & KERNFS_REMOVED) |
435 | return -ENOENT; | |
436 | ||
c637b8ac | 437 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
fd7b9f7b | 438 | |
c637b8ac | 439 | ret = kernfs_link_sibling(kn); |
fd7b9f7b | 440 | if (ret) |
7653fe9d | 441 | return ret; |
fd7b9f7b TH |
442 | |
443 | /* Update timestamps on the parent */ | |
adc5e8b5 | 444 | ps_iattr = parent->iattr; |
fd7b9f7b TH |
445 | if (ps_iattr) { |
446 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
447 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
448 | } | |
449 | ||
450 | /* Mark the entry added into directory tree */ | |
798c75a0 GKH |
451 | kn->flags &= ~KERNFS_REMOVED; |
452 | ||
7653fe9d GKH |
453 | return 0; |
454 | } | |
455 | ||
4f4b1b64 GKH |
456 | /** |
457 | * kernfs_remove_one - remove kernfs_node from parent | |
458 | * @acxt: addrm context to use | |
459 | * @kn: kernfs_node to be removed | |
460 | * | |
461 | * Mark @kn removed and drop nlink of parent inode if @kn is a | |
462 | * directory. @kn is unlinked from the children list. | |
463 | * | |
464 | * This function should be called between calls to | |
465 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be | |
466 | * passed the same @acxt as passed to kernfs_addrm_start(). | |
467 | * | |
468 | * LOCKING: | |
469 | * Determined by kernfs_addrm_start(). | |
470 | */ | |
471 | static void kernfs_remove_one(struct kernfs_addrm_cxt *acxt, | |
472 | struct kernfs_node *kn) | |
473 | { | |
474 | struct kernfs_iattrs *ps_iattr; | |
475 | ||
476 | /* | |
477 | * Removal can be called multiple times on the same node. Only the | |
478 | * first invocation is effective and puts the base ref. | |
479 | */ | |
798c75a0 | 480 | if (kn->flags & KERNFS_REMOVED) |
4f4b1b64 GKH |
481 | return; |
482 | ||
483 | if (kn->parent) { | |
484 | kernfs_unlink_sibling(kn); | |
485 | ||
486 | /* Update timestamps on the parent */ | |
487 | ps_iattr = kn->parent->iattr; | |
488 | if (ps_iattr) { | |
489 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
490 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
491 | } | |
492 | } | |
493 | ||
798c75a0 | 494 | kn->flags |= KERNFS_REMOVED; |
4f4b1b64 GKH |
495 | kn->u.removed_list = acxt->removed; |
496 | acxt->removed = kn; | |
497 | } | |
498 | ||
7653fe9d GKH |
499 | /** |
500 | * kernfs_addrm_finish - finish up kernfs_node add/remove | |
501 | * @acxt: addrm context to finish up | |
502 | * | |
503 | * Finish up kernfs_node add/remove. Resources acquired by | |
504 | * kernfs_addrm_start() are released and removed kernfs_nodes are | |
505 | * cleaned up. | |
506 | * | |
507 | * LOCKING: | |
508 | * kernfs_mutex is released. | |
509 | */ | |
510 | void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt) | |
511 | __releases(kernfs_mutex) | |
512 | { | |
513 | /* release resources acquired by kernfs_addrm_start() */ | |
a797bfc3 | 514 | mutex_unlock(&kernfs_mutex); |
7653fe9d GKH |
515 | |
516 | /* kill removed kernfs_nodes */ | |
517 | while (acxt->removed) { | |
518 | struct kernfs_node *kn = acxt->removed; | |
519 | ||
520 | acxt->removed = kn->u.removed_list; | |
521 | ||
798c75a0 | 522 | kernfs_deactivate(kn); |
55f6e30d | 523 | kernfs_unmap_bin_file(kn); |
7653fe9d GKH |
524 | kernfs_put(kn); |
525 | } | |
fd7b9f7b TH |
526 | } |
527 | ||
528 | /** | |
324a56e1 TH |
529 | * kernfs_find_ns - find kernfs_node with the given name |
530 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
531 | * @name: name to look for |
532 | * @ns: the namespace tag to use | |
533 | * | |
324a56e1 TH |
534 | * Look for kernfs_node with name @name under @parent. Returns pointer to |
535 | * the found kernfs_node on success, %NULL on failure. | |
fd7b9f7b | 536 | */ |
324a56e1 TH |
537 | static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, |
538 | const unsigned char *name, | |
539 | const void *ns) | |
fd7b9f7b | 540 | { |
adc5e8b5 | 541 | struct rb_node *node = parent->dir.children.rb_node; |
ac9bba03 | 542 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
543 | unsigned int hash; |
544 | ||
a797bfc3 | 545 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
546 | |
547 | if (has_ns != (bool)ns) { | |
c637b8ac | 548 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", |
adc5e8b5 | 549 | has_ns ? "required" : "invalid", parent->name, name); |
fd7b9f7b TH |
550 | return NULL; |
551 | } | |
552 | ||
c637b8ac | 553 | hash = kernfs_name_hash(name, ns); |
fd7b9f7b | 554 | while (node) { |
324a56e1 | 555 | struct kernfs_node *kn; |
fd7b9f7b TH |
556 | int result; |
557 | ||
324a56e1 | 558 | kn = rb_to_kn(node); |
c637b8ac | 559 | result = kernfs_name_compare(hash, name, ns, kn); |
fd7b9f7b TH |
560 | if (result < 0) |
561 | node = node->rb_left; | |
562 | else if (result > 0) | |
563 | node = node->rb_right; | |
564 | else | |
324a56e1 | 565 | return kn; |
fd7b9f7b TH |
566 | } |
567 | return NULL; | |
568 | } | |
569 | ||
570 | /** | |
324a56e1 TH |
571 | * kernfs_find_and_get_ns - find and get kernfs_node with the given name |
572 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
573 | * @name: name to look for |
574 | * @ns: the namespace tag to use | |
575 | * | |
324a56e1 | 576 | * Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b | 577 | * if found. This function may sleep and returns pointer to the found |
324a56e1 | 578 | * kernfs_node on success, %NULL on failure. |
fd7b9f7b | 579 | */ |
324a56e1 TH |
580 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
581 | const char *name, const void *ns) | |
fd7b9f7b | 582 | { |
324a56e1 | 583 | struct kernfs_node *kn; |
fd7b9f7b | 584 | |
a797bfc3 | 585 | mutex_lock(&kernfs_mutex); |
324a56e1 TH |
586 | kn = kernfs_find_ns(parent, name, ns); |
587 | kernfs_get(kn); | |
a797bfc3 | 588 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 589 | |
324a56e1 | 590 | return kn; |
fd7b9f7b TH |
591 | } |
592 | EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); | |
593 | ||
ba7443bc TH |
594 | /** |
595 | * kernfs_create_root - create a new kernfs hierarchy | |
80b9bbef | 596 | * @kdops: optional directory syscall operations for the hierarchy |
ba7443bc TH |
597 | * @priv: opaque data associated with the new directory |
598 | * | |
599 | * Returns the root of the new hierarchy on success, ERR_PTR() value on | |
600 | * failure. | |
601 | */ | |
80b9bbef | 602 | struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv) |
ba7443bc TH |
603 | { |
604 | struct kernfs_root *root; | |
324a56e1 | 605 | struct kernfs_node *kn; |
ba7443bc TH |
606 | |
607 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
608 | if (!root) | |
609 | return ERR_PTR(-ENOMEM); | |
610 | ||
bc755553 TH |
611 | ida_init(&root->ino_ida); |
612 | ||
db4aad20 TH |
613 | kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, |
614 | KERNFS_DIR); | |
324a56e1 | 615 | if (!kn) { |
bc755553 | 616 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
617 | kfree(root); |
618 | return ERR_PTR(-ENOMEM); | |
619 | } | |
620 | ||
798c75a0 | 621 | kn->flags &= ~KERNFS_REMOVED; |
324a56e1 | 622 | kn->priv = priv; |
adc5e8b5 | 623 | kn->dir.root = root; |
ba7443bc | 624 | |
80b9bbef | 625 | root->dir_ops = kdops; |
324a56e1 | 626 | root->kn = kn; |
abd54f02 | 627 | init_waitqueue_head(&root->deactivate_waitq); |
ba7443bc TH |
628 | |
629 | return root; | |
630 | } | |
631 | ||
632 | /** | |
633 | * kernfs_destroy_root - destroy a kernfs hierarchy | |
634 | * @root: root of the hierarchy to destroy | |
635 | * | |
636 | * Destroy the hierarchy anchored at @root by removing all existing | |
637 | * directories and destroying @root. | |
638 | */ | |
639 | void kernfs_destroy_root(struct kernfs_root *root) | |
640 | { | |
324a56e1 | 641 | kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc TH |
642 | } |
643 | ||
fd7b9f7b TH |
644 | /** |
645 | * kernfs_create_dir_ns - create a directory | |
646 | * @parent: parent in which to create a new directory | |
647 | * @name: name of the new directory | |
bb8b9d09 | 648 | * @mode: mode of the new directory |
fd7b9f7b TH |
649 | * @priv: opaque data associated with the new directory |
650 | * @ns: optional namespace tag of the directory | |
651 | * | |
652 | * Returns the created node on success, ERR_PTR() value on failure. | |
653 | */ | |
324a56e1 | 654 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d09 TH |
655 | const char *name, umode_t mode, |
656 | void *priv, const void *ns) | |
fd7b9f7b | 657 | { |
7653fe9d | 658 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 659 | struct kernfs_node *kn; |
fd7b9f7b TH |
660 | int rc; |
661 | ||
662 | /* allocate */ | |
db4aad20 | 663 | kn = kernfs_new_node(parent, name, mode | S_IFDIR, KERNFS_DIR); |
324a56e1 | 664 | if (!kn) |
fd7b9f7b TH |
665 | return ERR_PTR(-ENOMEM); |
666 | ||
adc5e8b5 TH |
667 | kn->dir.root = parent->dir.root; |
668 | kn->ns = ns; | |
324a56e1 | 669 | kn->priv = priv; |
fd7b9f7b TH |
670 | |
671 | /* link in */ | |
798c75a0 | 672 | kernfs_addrm_start(&acxt); |
db4aad20 | 673 | rc = kernfs_add_one(&acxt, kn); |
798c75a0 | 674 | kernfs_addrm_finish(&acxt); |
7653fe9d | 675 | |
fd7b9f7b | 676 | if (!rc) |
324a56e1 | 677 | return kn; |
fd7b9f7b | 678 | |
324a56e1 | 679 | kernfs_put(kn); |
fd7b9f7b TH |
680 | return ERR_PTR(rc); |
681 | } | |
682 | ||
c637b8ac TH |
683 | static struct dentry *kernfs_iop_lookup(struct inode *dir, |
684 | struct dentry *dentry, | |
685 | unsigned int flags) | |
fd7b9f7b | 686 | { |
19bbb926 | 687 | struct dentry *ret; |
324a56e1 TH |
688 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
689 | struct kernfs_node *kn; | |
fd7b9f7b TH |
690 | struct inode *inode; |
691 | const void *ns = NULL; | |
692 | ||
a797bfc3 | 693 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 694 | |
324a56e1 | 695 | if (kernfs_ns_enabled(parent)) |
c525aadd | 696 | ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b | 697 | |
324a56e1 | 698 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
699 | |
700 | /* no such entry */ | |
324a56e1 | 701 | if (!kn) { |
19bbb926 | 702 | ret = NULL; |
fd7b9f7b TH |
703 | goto out_unlock; |
704 | } | |
324a56e1 TH |
705 | kernfs_get(kn); |
706 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
707 | |
708 | /* attach dentry and inode */ | |
c637b8ac | 709 | inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
710 | if (!inode) { |
711 | ret = ERR_PTR(-ENOMEM); | |
712 | goto out_unlock; | |
713 | } | |
714 | ||
715 | /* instantiate and hash dentry */ | |
716 | ret = d_materialise_unique(dentry, inode); | |
717 | out_unlock: | |
a797bfc3 | 718 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
719 | return ret; |
720 | } | |
721 | ||
80b9bbef TH |
722 | static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, |
723 | umode_t mode) | |
724 | { | |
725 | struct kernfs_node *parent = dir->i_private; | |
726 | struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops; | |
727 | ||
728 | if (!kdops || !kdops->mkdir) | |
729 | return -EPERM; | |
730 | ||
731 | return kdops->mkdir(parent, dentry->d_name.name, mode); | |
732 | } | |
733 | ||
734 | static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) | |
735 | { | |
736 | struct kernfs_node *kn = dentry->d_fsdata; | |
737 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
738 | ||
739 | if (!kdops || !kdops->rmdir) | |
740 | return -EPERM; | |
741 | ||
742 | return kdops->rmdir(kn); | |
743 | } | |
744 | ||
745 | static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, | |
746 | struct inode *new_dir, struct dentry *new_dentry) | |
747 | { | |
748 | struct kernfs_node *kn = old_dentry->d_fsdata; | |
749 | struct kernfs_node *new_parent = new_dir->i_private; | |
750 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
751 | ||
752 | if (!kdops || !kdops->rename) | |
753 | return -EPERM; | |
754 | ||
755 | return kdops->rename(kn, new_parent, new_dentry->d_name.name); | |
756 | } | |
757 | ||
a797bfc3 | 758 | const struct inode_operations kernfs_dir_iops = { |
c637b8ac TH |
759 | .lookup = kernfs_iop_lookup, |
760 | .permission = kernfs_iop_permission, | |
761 | .setattr = kernfs_iop_setattr, | |
762 | .getattr = kernfs_iop_getattr, | |
763 | .setxattr = kernfs_iop_setxattr, | |
764 | .removexattr = kernfs_iop_removexattr, | |
765 | .getxattr = kernfs_iop_getxattr, | |
766 | .listxattr = kernfs_iop_listxattr, | |
80b9bbef TH |
767 | |
768 | .mkdir = kernfs_iop_mkdir, | |
769 | .rmdir = kernfs_iop_rmdir, | |
770 | .rename = kernfs_iop_rename, | |
fd7b9f7b TH |
771 | }; |
772 | ||
c637b8ac | 773 | static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 774 | { |
324a56e1 | 775 | struct kernfs_node *last; |
fd7b9f7b TH |
776 | |
777 | while (true) { | |
778 | struct rb_node *rbn; | |
779 | ||
780 | last = pos; | |
781 | ||
df23fc39 | 782 | if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b TH |
783 | break; |
784 | ||
adc5e8b5 | 785 | rbn = rb_first(&pos->dir.children); |
fd7b9f7b TH |
786 | if (!rbn) |
787 | break; | |
788 | ||
324a56e1 | 789 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
790 | } |
791 | ||
792 | return last; | |
793 | } | |
794 | ||
795 | /** | |
c637b8ac | 796 | * kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b | 797 | * @pos: the current position (%NULL to initiate traversal) |
324a56e1 | 798 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
799 | * |
800 | * Find the next descendant to visit for post-order traversal of @root's | |
801 | * descendants. @root is included in the iteration and the last node to be | |
802 | * visited. | |
803 | */ | |
c637b8ac TH |
804 | static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, |
805 | struct kernfs_node *root) | |
fd7b9f7b TH |
806 | { |
807 | struct rb_node *rbn; | |
808 | ||
a797bfc3 | 809 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
810 | |
811 | /* if first iteration, visit leftmost descendant which may be root */ | |
812 | if (!pos) | |
c637b8ac | 813 | return kernfs_leftmost_descendant(root); |
fd7b9f7b TH |
814 | |
815 | /* if we visited @root, we're done */ | |
816 | if (pos == root) | |
817 | return NULL; | |
818 | ||
819 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
adc5e8b5 | 820 | rbn = rb_next(&pos->rb); |
fd7b9f7b | 821 | if (rbn) |
c637b8ac | 822 | return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
823 | |
824 | /* no sibling left, visit parent */ | |
adc5e8b5 | 825 | return pos->parent; |
fd7b9f7b TH |
826 | } |
827 | ||
7653fe9d GKH |
828 | static void __kernfs_remove(struct kernfs_addrm_cxt *acxt, |
829 | struct kernfs_node *kn) | |
fd7b9f7b | 830 | { |
4f4b1b64 | 831 | struct kernfs_node *pos, *next; |
fd7b9f7b | 832 | |
ce9b499c GKH |
833 | if (!kn) |
834 | return; | |
835 | ||
c637b8ac | 836 | pr_debug("kernfs %s: removing\n", kn->name); |
fd7b9f7b | 837 | |
4f4b1b64 | 838 | next = NULL; |
fd7b9f7b | 839 | do { |
4f4b1b64 GKH |
840 | pos = next; |
841 | next = kernfs_next_descendant_post(pos, kn); | |
842 | if (pos) | |
843 | kernfs_remove_one(acxt, pos); | |
844 | } while (next); | |
fd7b9f7b TH |
845 | } |
846 | ||
847 | /** | |
324a56e1 TH |
848 | * kernfs_remove - remove a kernfs_node recursively |
849 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 850 | * |
324a56e1 | 851 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 852 | */ |
324a56e1 | 853 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 854 | { |
7653fe9d GKH |
855 | struct kernfs_addrm_cxt acxt; |
856 | ||
857 | kernfs_addrm_start(&acxt); | |
858 | __kernfs_remove(&acxt, kn); | |
859 | kernfs_addrm_finish(&acxt); | |
fd7b9f7b TH |
860 | } |
861 | ||
862 | /** | |
324a56e1 TH |
863 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
864 | * @parent: parent of the target | |
865 | * @name: name of the kernfs_node to remove | |
866 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 867 | * |
324a56e1 TH |
868 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
869 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 870 | */ |
324a56e1 | 871 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
872 | const void *ns) |
873 | { | |
7653fe9d | 874 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 875 | struct kernfs_node *kn; |
fd7b9f7b | 876 | |
324a56e1 | 877 | if (!parent) { |
c637b8ac | 878 | WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n", |
fd7b9f7b TH |
879 | name); |
880 | return -ENOENT; | |
881 | } | |
882 | ||
7653fe9d | 883 | kernfs_addrm_start(&acxt); |
fd7b9f7b | 884 | |
324a56e1 TH |
885 | kn = kernfs_find_ns(parent, name, ns); |
886 | if (kn) | |
7653fe9d | 887 | __kernfs_remove(&acxt, kn); |
fd7b9f7b | 888 | |
7653fe9d | 889 | kernfs_addrm_finish(&acxt); |
fd7b9f7b | 890 | |
324a56e1 | 891 | if (kn) |
fd7b9f7b TH |
892 | return 0; |
893 | else | |
894 | return -ENOENT; | |
895 | } | |
896 | ||
897 | /** | |
898 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 899 | * @kn: target node |
fd7b9f7b TH |
900 | * @new_parent: new parent to put @sd under |
901 | * @new_name: new name | |
902 | * @new_ns: new namespace tag | |
903 | */ | |
324a56e1 | 904 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
905 | const char *new_name, const void *new_ns) |
906 | { | |
907 | int error; | |
908 | ||
798c75a0 GKH |
909 | mutex_lock(&kernfs_mutex); |
910 | ||
d0ae3d43 | 911 | error = -ENOENT; |
798c75a0 | 912 | if ((kn->flags | new_parent->flags) & KERNFS_REMOVED) |
d0ae3d43 TH |
913 | goto out; |
914 | ||
fd7b9f7b | 915 | error = 0; |
adc5e8b5 TH |
916 | if ((kn->parent == new_parent) && (kn->ns == new_ns) && |
917 | (strcmp(kn->name, new_name) == 0)) | |
798c75a0 | 918 | goto out; /* nothing to rename */ |
fd7b9f7b TH |
919 | |
920 | error = -EEXIST; | |
921 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
798c75a0 | 922 | goto out; |
fd7b9f7b | 923 | |
324a56e1 | 924 | /* rename kernfs_node */ |
adc5e8b5 | 925 | if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b TH |
926 | error = -ENOMEM; |
927 | new_name = kstrdup(new_name, GFP_KERNEL); | |
928 | if (!new_name) | |
798c75a0 | 929 | goto out; |
fd7b9f7b | 930 | |
47a52e91 TH |
931 | if (kn->flags & KERNFS_STATIC_NAME) |
932 | kn->flags &= ~KERNFS_STATIC_NAME; | |
933 | else | |
934 | kfree(kn->name); | |
935 | ||
adc5e8b5 | 936 | kn->name = new_name; |
fd7b9f7b TH |
937 | } |
938 | ||
939 | /* | |
940 | * Move to the appropriate place in the appropriate directories rbtree. | |
941 | */ | |
c637b8ac | 942 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 943 | kernfs_get(new_parent); |
adc5e8b5 TH |
944 | kernfs_put(kn->parent); |
945 | kn->ns = new_ns; | |
c637b8ac | 946 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 947 | kn->parent = new_parent; |
c637b8ac | 948 | kernfs_link_sibling(kn); |
fd7b9f7b TH |
949 | |
950 | error = 0; | |
798c75a0 | 951 | out: |
a797bfc3 | 952 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
953 | return error; |
954 | } | |
955 | ||
fd7b9f7b | 956 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 957 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 958 | { |
adc5e8b5 | 959 | return (kn->mode >> 12) & 15; |
fd7b9f7b TH |
960 | } |
961 | ||
c637b8ac | 962 | static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b TH |
963 | { |
964 | kernfs_put(filp->private_data); | |
965 | return 0; | |
966 | } | |
967 | ||
c637b8ac | 968 | static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e1 | 969 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b TH |
970 | { |
971 | if (pos) { | |
798c75a0 GKH |
972 | int valid = !(pos->flags & KERNFS_REMOVED) && |
973 | pos->parent == parent && hash == pos->hash; | |
fd7b9f7b TH |
974 | kernfs_put(pos); |
975 | if (!valid) | |
976 | pos = NULL; | |
977 | } | |
978 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
adc5e8b5 | 979 | struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b | 980 | while (node) { |
324a56e1 | 981 | pos = rb_to_kn(node); |
fd7b9f7b | 982 | |
adc5e8b5 | 983 | if (hash < pos->hash) |
fd7b9f7b | 984 | node = node->rb_left; |
adc5e8b5 | 985 | else if (hash > pos->hash) |
fd7b9f7b TH |
986 | node = node->rb_right; |
987 | else | |
988 | break; | |
989 | } | |
990 | } | |
991 | /* Skip over entries in the wrong namespace */ | |
adc5e8b5 TH |
992 | while (pos && pos->ns != ns) { |
993 | struct rb_node *node = rb_next(&pos->rb); | |
fd7b9f7b TH |
994 | if (!node) |
995 | pos = NULL; | |
996 | else | |
324a56e1 | 997 | pos = rb_to_kn(node); |
fd7b9f7b TH |
998 | } |
999 | return pos; | |
1000 | } | |
1001 | ||
c637b8ac | 1002 | static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e1 | 1003 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b | 1004 | { |
c637b8ac | 1005 | pos = kernfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
1006 | if (pos) |
1007 | do { | |
adc5e8b5 | 1008 | struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b TH |
1009 | if (!node) |
1010 | pos = NULL; | |
1011 | else | |
324a56e1 | 1012 | pos = rb_to_kn(node); |
adc5e8b5 | 1013 | } while (pos && pos->ns != ns); |
fd7b9f7b TH |
1014 | return pos; |
1015 | } | |
1016 | ||
c637b8ac | 1017 | static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b TH |
1018 | { |
1019 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
1020 | struct kernfs_node *parent = dentry->d_fsdata; |
1021 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
1022 | const void *ns = NULL; |
1023 | ||
1024 | if (!dir_emit_dots(file, ctx)) | |
1025 | return 0; | |
a797bfc3 | 1026 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1027 | |
324a56e1 | 1028 | if (kernfs_ns_enabled(parent)) |
c525aadd | 1029 | ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b | 1030 | |
c637b8ac | 1031 | for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 1032 | pos; |
c637b8ac | 1033 | pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b5 | 1034 | const char *name = pos->name; |
fd7b9f7b TH |
1035 | unsigned int type = dt_type(pos); |
1036 | int len = strlen(name); | |
adc5e8b5 | 1037 | ino_t ino = pos->ino; |
fd7b9f7b | 1038 | |
adc5e8b5 | 1039 | ctx->pos = pos->hash; |
fd7b9f7b TH |
1040 | file->private_data = pos; |
1041 | kernfs_get(pos); | |
1042 | ||
a797bfc3 | 1043 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1044 | if (!dir_emit(ctx, name, len, ino, type)) |
1045 | return 0; | |
a797bfc3 | 1046 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1047 | } |
a797bfc3 | 1048 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1049 | file->private_data = NULL; |
1050 | ctx->pos = INT_MAX; | |
1051 | return 0; | |
1052 | } | |
1053 | ||
c637b8ac TH |
1054 | static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset, |
1055 | int whence) | |
fd7b9f7b TH |
1056 | { |
1057 | struct inode *inode = file_inode(file); | |
1058 | loff_t ret; | |
1059 | ||
1060 | mutex_lock(&inode->i_mutex); | |
1061 | ret = generic_file_llseek(file, offset, whence); | |
1062 | mutex_unlock(&inode->i_mutex); | |
1063 | ||
1064 | return ret; | |
1065 | } | |
1066 | ||
a797bfc3 | 1067 | const struct file_operations kernfs_dir_fops = { |
fd7b9f7b | 1068 | .read = generic_read_dir, |
c637b8ac TH |
1069 | .iterate = kernfs_fop_readdir, |
1070 | .release = kernfs_dir_fop_release, | |
1071 | .llseek = kernfs_dir_fop_llseek, | |
fd7b9f7b | 1072 | }; |