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