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 | */ |
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 | |
87da1493 GKH |
190 | rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); |
191 | /* atomic_add_return() is a mb(), put_active() will always see | |
192 | * the updated kn->u.completion. | |
193 | */ | |
194 | v = atomic_add_return(KN_DEACTIVATED_BIAS, &kn->active); | |
ea1c472d | 195 | |
87da1493 | 196 | if (v != KN_DEACTIVATED_BIAS) { |
0890147f | 197 | lock_contended(&kn->dep_map, _RET_IP_); |
87da1493 GKH |
198 | wait_for_completion(&wait); |
199 | } | |
fd7b9f7b | 200 | |
0890147f GKH |
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 | 232 | repeat: |
798c75a0 | 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 | |
798c75a0 GKH |
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 | |
798c75a0 GKH |
281 | /* The kernfs node has been deleted */ |
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 | ||
db4aad20 TH |
327 | static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, |
328 | const char *name, umode_t mode, | |
329 | unsigned flags) | |
fd7b9f7b TH |
330 | { |
331 | char *dup_name = NULL; | |
324a56e1 | 332 | struct kernfs_node *kn; |
bc755553 | 333 | int ret; |
fd7b9f7b | 334 | |
2063d608 | 335 | if (!(flags & KERNFS_STATIC_NAME)) { |
fd7b9f7b TH |
336 | name = dup_name = kstrdup(name, GFP_KERNEL); |
337 | if (!name) | |
338 | return NULL; | |
339 | } | |
340 | ||
a797bfc3 | 341 | kn = kmem_cache_zalloc(kernfs_node_cache, GFP_KERNEL); |
324a56e1 | 342 | if (!kn) |
fd7b9f7b TH |
343 | goto err_out1; |
344 | ||
bc755553 TH |
345 | ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL); |
346 | if (ret < 0) | |
fd7b9f7b | 347 | goto err_out2; |
adc5e8b5 | 348 | kn->ino = ret; |
fd7b9f7b | 349 | |
adc5e8b5 | 350 | atomic_set(&kn->count, 1); |
798c75a0 | 351 | atomic_set(&kn->active, 0); |
fd7b9f7b | 352 | |
adc5e8b5 TH |
353 | kn->name = name; |
354 | kn->mode = mode; | |
798c75a0 | 355 | kn->flags = flags | KERNFS_REMOVED; |
fd7b9f7b | 356 | |
324a56e1 | 357 | return kn; |
fd7b9f7b TH |
358 | |
359 | err_out2: | |
a797bfc3 | 360 | kmem_cache_free(kernfs_node_cache, kn); |
fd7b9f7b TH |
361 | err_out1: |
362 | kfree(dup_name); | |
363 | return NULL; | |
364 | } | |
365 | ||
db4aad20 TH |
366 | struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, |
367 | const char *name, umode_t mode, | |
368 | unsigned flags) | |
369 | { | |
370 | struct kernfs_node *kn; | |
371 | ||
372 | kn = __kernfs_new_node(kernfs_root(parent), name, mode, flags); | |
373 | if (kn) { | |
374 | kernfs_get(parent); | |
375 | kn->parent = parent; | |
376 | } | |
377 | return kn; | |
378 | } | |
379 | ||
7653fe9d GKH |
380 | /** |
381 | * kernfs_addrm_start - prepare for kernfs_node add/remove | |
382 | * @acxt: pointer to kernfs_addrm_cxt to be used | |
383 | * | |
384 | * This function is called when the caller is about to add or remove | |
385 | * kernfs_node. This function acquires kernfs_mutex. @acxt is used | |
386 | * to keep and pass context to other addrm functions. | |
387 | * | |
388 | * LOCKING: | |
389 | * Kernel thread context (may sleep). kernfs_mutex is locked on | |
390 | * return. | |
391 | */ | |
392 | void kernfs_addrm_start(struct kernfs_addrm_cxt *acxt) | |
393 | __acquires(kernfs_mutex) | |
394 | { | |
395 | memset(acxt, 0, sizeof(*acxt)); | |
396 | ||
397 | mutex_lock(&kernfs_mutex); | |
398 | } | |
399 | ||
fd7b9f7b | 400 | /** |
c637b8ac | 401 | * kernfs_add_one - add kernfs_node to parent without warning |
7653fe9d | 402 | * @acxt: addrm context to use |
324a56e1 | 403 | * @kn: kernfs_node to be added |
fd7b9f7b | 404 | * |
db4aad20 TH |
405 | * The caller must already have initialized @kn->parent. This |
406 | * function increments nlink of the parent's inode if @kn is a | |
407 | * directory and link into the children list of the parent. | |
fd7b9f7b | 408 | * |
7653fe9d GKH |
409 | * This function should be called between calls to |
410 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be passed | |
411 | * the same @acxt as passed to kernfs_addrm_start(). | |
412 | * | |
413 | * LOCKING: | |
414 | * Determined by kernfs_addrm_start(). | |
415 | * | |
fd7b9f7b TH |
416 | * RETURNS: |
417 | * 0 on success, -EEXIST if entry with the given name already | |
418 | * exists. | |
419 | */ | |
db4aad20 | 420 | int kernfs_add_one(struct kernfs_addrm_cxt *acxt, struct kernfs_node *kn) |
fd7b9f7b | 421 | { |
db4aad20 | 422 | struct kernfs_node *parent = kn->parent; |
7653fe9d | 423 | bool has_ns = kernfs_ns_enabled(parent); |
c525aadd | 424 | struct kernfs_iattrs *ps_iattr; |
fd7b9f7b TH |
425 | int ret; |
426 | ||
7653fe9d GKH |
427 | if (has_ns != (bool)kn->ns) { |
428 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", | |
429 | has_ns ? "required" : "invalid", parent->name, kn->name); | |
430 | return -EINVAL; | |
431 | } | |
fd7b9f7b | 432 | |
df23fc39 | 433 | if (kernfs_type(parent) != KERNFS_DIR) |
7653fe9d | 434 | return -EINVAL; |
fd7b9f7b | 435 | |
798c75a0 GKH |
436 | if (parent->flags & KERNFS_REMOVED) |
437 | return -ENOENT; | |
438 | ||
c637b8ac | 439 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
fd7b9f7b | 440 | |
c637b8ac | 441 | ret = kernfs_link_sibling(kn); |
fd7b9f7b | 442 | if (ret) |
7653fe9d | 443 | return ret; |
fd7b9f7b TH |
444 | |
445 | /* Update timestamps on the parent */ | |
adc5e8b5 | 446 | ps_iattr = parent->iattr; |
fd7b9f7b TH |
447 | if (ps_iattr) { |
448 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
449 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
450 | } | |
451 | ||
452 | /* Mark the entry added into directory tree */ | |
798c75a0 GKH |
453 | kn->flags &= ~KERNFS_REMOVED; |
454 | ||
7653fe9d GKH |
455 | return 0; |
456 | } | |
457 | ||
4f4b1b64 GKH |
458 | /** |
459 | * kernfs_remove_one - remove kernfs_node from parent | |
460 | * @acxt: addrm context to use | |
461 | * @kn: kernfs_node to be removed | |
462 | * | |
463 | * Mark @kn removed and drop nlink of parent inode if @kn is a | |
464 | * directory. @kn is unlinked from the children list. | |
465 | * | |
466 | * This function should be called between calls to | |
467 | * kernfs_addrm_start() and kernfs_addrm_finish() and should be | |
468 | * passed the same @acxt as passed to kernfs_addrm_start(). | |
469 | * | |
470 | * LOCKING: | |
471 | * Determined by kernfs_addrm_start(). | |
472 | */ | |
473 | static void kernfs_remove_one(struct kernfs_addrm_cxt *acxt, | |
474 | struct kernfs_node *kn) | |
475 | { | |
476 | struct kernfs_iattrs *ps_iattr; | |
477 | ||
478 | /* | |
479 | * Removal can be called multiple times on the same node. Only the | |
480 | * first invocation is effective and puts the base ref. | |
481 | */ | |
798c75a0 | 482 | if (kn->flags & KERNFS_REMOVED) |
4f4b1b64 GKH |
483 | return; |
484 | ||
485 | if (kn->parent) { | |
486 | kernfs_unlink_sibling(kn); | |
487 | ||
488 | /* Update timestamps on the parent */ | |
489 | ps_iattr = kn->parent->iattr; | |
490 | if (ps_iattr) { | |
491 | ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME; | |
492 | ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME; | |
493 | } | |
494 | } | |
495 | ||
798c75a0 | 496 | kn->flags |= KERNFS_REMOVED; |
4f4b1b64 GKH |
497 | kn->u.removed_list = acxt->removed; |
498 | acxt->removed = kn; | |
499 | } | |
500 | ||
7653fe9d GKH |
501 | /** |
502 | * kernfs_addrm_finish - finish up kernfs_node add/remove | |
503 | * @acxt: addrm context to finish up | |
504 | * | |
505 | * Finish up kernfs_node add/remove. Resources acquired by | |
506 | * kernfs_addrm_start() are released and removed kernfs_nodes are | |
507 | * cleaned up. | |
508 | * | |
509 | * LOCKING: | |
510 | * kernfs_mutex is released. | |
511 | */ | |
512 | void kernfs_addrm_finish(struct kernfs_addrm_cxt *acxt) | |
513 | __releases(kernfs_mutex) | |
514 | { | |
515 | /* release resources acquired by kernfs_addrm_start() */ | |
a797bfc3 | 516 | mutex_unlock(&kernfs_mutex); |
7653fe9d GKH |
517 | |
518 | /* kill removed kernfs_nodes */ | |
519 | while (acxt->removed) { | |
520 | struct kernfs_node *kn = acxt->removed; | |
521 | ||
522 | acxt->removed = kn->u.removed_list; | |
523 | ||
798c75a0 | 524 | kernfs_deactivate(kn); |
55f6e30d | 525 | kernfs_unmap_bin_file(kn); |
7653fe9d GKH |
526 | kernfs_put(kn); |
527 | } | |
fd7b9f7b TH |
528 | } |
529 | ||
530 | /** | |
324a56e1 TH |
531 | * kernfs_find_ns - find kernfs_node with the given name |
532 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
533 | * @name: name to look for |
534 | * @ns: the namespace tag to use | |
535 | * | |
324a56e1 TH |
536 | * Look for kernfs_node with name @name under @parent. Returns pointer to |
537 | * the found kernfs_node on success, %NULL on failure. | |
fd7b9f7b | 538 | */ |
324a56e1 TH |
539 | static struct kernfs_node *kernfs_find_ns(struct kernfs_node *parent, |
540 | const unsigned char *name, | |
541 | const void *ns) | |
fd7b9f7b | 542 | { |
adc5e8b5 | 543 | struct rb_node *node = parent->dir.children.rb_node; |
ac9bba03 | 544 | bool has_ns = kernfs_ns_enabled(parent); |
fd7b9f7b TH |
545 | unsigned int hash; |
546 | ||
a797bfc3 | 547 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
548 | |
549 | if (has_ns != (bool)ns) { | |
c637b8ac | 550 | WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n", |
adc5e8b5 | 551 | has_ns ? "required" : "invalid", parent->name, name); |
fd7b9f7b TH |
552 | return NULL; |
553 | } | |
554 | ||
c637b8ac | 555 | hash = kernfs_name_hash(name, ns); |
fd7b9f7b | 556 | while (node) { |
324a56e1 | 557 | struct kernfs_node *kn; |
fd7b9f7b TH |
558 | int result; |
559 | ||
324a56e1 | 560 | kn = rb_to_kn(node); |
c637b8ac | 561 | result = kernfs_name_compare(hash, name, ns, kn); |
fd7b9f7b TH |
562 | if (result < 0) |
563 | node = node->rb_left; | |
564 | else if (result > 0) | |
565 | node = node->rb_right; | |
566 | else | |
324a56e1 | 567 | return kn; |
fd7b9f7b TH |
568 | } |
569 | return NULL; | |
570 | } | |
571 | ||
572 | /** | |
324a56e1 TH |
573 | * kernfs_find_and_get_ns - find and get kernfs_node with the given name |
574 | * @parent: kernfs_node to search under | |
fd7b9f7b TH |
575 | * @name: name to look for |
576 | * @ns: the namespace tag to use | |
577 | * | |
324a56e1 | 578 | * Look for kernfs_node with name @name under @parent and get a reference |
fd7b9f7b | 579 | * if found. This function may sleep and returns pointer to the found |
324a56e1 | 580 | * kernfs_node on success, %NULL on failure. |
fd7b9f7b | 581 | */ |
324a56e1 TH |
582 | struct kernfs_node *kernfs_find_and_get_ns(struct kernfs_node *parent, |
583 | const char *name, const void *ns) | |
fd7b9f7b | 584 | { |
324a56e1 | 585 | struct kernfs_node *kn; |
fd7b9f7b | 586 | |
a797bfc3 | 587 | mutex_lock(&kernfs_mutex); |
324a56e1 TH |
588 | kn = kernfs_find_ns(parent, name, ns); |
589 | kernfs_get(kn); | |
a797bfc3 | 590 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b | 591 | |
324a56e1 | 592 | return kn; |
fd7b9f7b TH |
593 | } |
594 | EXPORT_SYMBOL_GPL(kernfs_find_and_get_ns); | |
595 | ||
ba7443bc TH |
596 | /** |
597 | * kernfs_create_root - create a new kernfs hierarchy | |
80b9bbef | 598 | * @kdops: optional directory syscall operations for the hierarchy |
ba7443bc TH |
599 | * @priv: opaque data associated with the new directory |
600 | * | |
601 | * Returns the root of the new hierarchy on success, ERR_PTR() value on | |
602 | * failure. | |
603 | */ | |
80b9bbef | 604 | struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv) |
ba7443bc TH |
605 | { |
606 | struct kernfs_root *root; | |
324a56e1 | 607 | struct kernfs_node *kn; |
ba7443bc TH |
608 | |
609 | root = kzalloc(sizeof(*root), GFP_KERNEL); | |
610 | if (!root) | |
611 | return ERR_PTR(-ENOMEM); | |
612 | ||
bc755553 TH |
613 | ida_init(&root->ino_ida); |
614 | ||
db4aad20 TH |
615 | kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, |
616 | KERNFS_DIR); | |
324a56e1 | 617 | if (!kn) { |
bc755553 | 618 | ida_destroy(&root->ino_ida); |
ba7443bc TH |
619 | kfree(root); |
620 | return ERR_PTR(-ENOMEM); | |
621 | } | |
622 | ||
798c75a0 | 623 | kn->flags &= ~KERNFS_REMOVED; |
324a56e1 | 624 | kn->priv = priv; |
adc5e8b5 | 625 | kn->dir.root = root; |
ba7443bc | 626 | |
80b9bbef | 627 | root->dir_ops = kdops; |
324a56e1 | 628 | root->kn = kn; |
ba7443bc TH |
629 | |
630 | return root; | |
631 | } | |
632 | ||
633 | /** | |
634 | * kernfs_destroy_root - destroy a kernfs hierarchy | |
635 | * @root: root of the hierarchy to destroy | |
636 | * | |
637 | * Destroy the hierarchy anchored at @root by removing all existing | |
638 | * directories and destroying @root. | |
639 | */ | |
640 | void kernfs_destroy_root(struct kernfs_root *root) | |
641 | { | |
324a56e1 | 642 | kernfs_remove(root->kn); /* will also free @root */ |
ba7443bc TH |
643 | } |
644 | ||
fd7b9f7b TH |
645 | /** |
646 | * kernfs_create_dir_ns - create a directory | |
647 | * @parent: parent in which to create a new directory | |
648 | * @name: name of the new directory | |
bb8b9d09 | 649 | * @mode: mode of the new directory |
fd7b9f7b TH |
650 | * @priv: opaque data associated with the new directory |
651 | * @ns: optional namespace tag of the directory | |
652 | * | |
653 | * Returns the created node on success, ERR_PTR() value on failure. | |
654 | */ | |
324a56e1 | 655 | struct kernfs_node *kernfs_create_dir_ns(struct kernfs_node *parent, |
bb8b9d09 TH |
656 | const char *name, umode_t mode, |
657 | void *priv, const void *ns) | |
fd7b9f7b | 658 | { |
7653fe9d | 659 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 660 | struct kernfs_node *kn; |
fd7b9f7b TH |
661 | int rc; |
662 | ||
663 | /* allocate */ | |
db4aad20 | 664 | kn = kernfs_new_node(parent, name, mode | S_IFDIR, KERNFS_DIR); |
324a56e1 | 665 | if (!kn) |
fd7b9f7b TH |
666 | return ERR_PTR(-ENOMEM); |
667 | ||
adc5e8b5 TH |
668 | kn->dir.root = parent->dir.root; |
669 | kn->ns = ns; | |
324a56e1 | 670 | kn->priv = priv; |
fd7b9f7b TH |
671 | |
672 | /* link in */ | |
798c75a0 | 673 | kernfs_addrm_start(&acxt); |
db4aad20 | 674 | rc = kernfs_add_one(&acxt, kn); |
798c75a0 | 675 | kernfs_addrm_finish(&acxt); |
7653fe9d | 676 | |
fd7b9f7b | 677 | if (!rc) |
324a56e1 | 678 | return kn; |
fd7b9f7b | 679 | |
324a56e1 | 680 | kernfs_put(kn); |
fd7b9f7b TH |
681 | return ERR_PTR(rc); |
682 | } | |
683 | ||
c637b8ac TH |
684 | static struct dentry *kernfs_iop_lookup(struct inode *dir, |
685 | struct dentry *dentry, | |
686 | unsigned int flags) | |
fd7b9f7b | 687 | { |
19bbb926 | 688 | struct dentry *ret; |
324a56e1 TH |
689 | struct kernfs_node *parent = dentry->d_parent->d_fsdata; |
690 | struct kernfs_node *kn; | |
fd7b9f7b TH |
691 | struct inode *inode; |
692 | const void *ns = NULL; | |
693 | ||
a797bfc3 | 694 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 695 | |
324a56e1 | 696 | if (kernfs_ns_enabled(parent)) |
c525aadd | 697 | ns = kernfs_info(dir->i_sb)->ns; |
fd7b9f7b | 698 | |
324a56e1 | 699 | kn = kernfs_find_ns(parent, dentry->d_name.name, ns); |
fd7b9f7b TH |
700 | |
701 | /* no such entry */ | |
324a56e1 | 702 | if (!kn) { |
19bbb926 | 703 | ret = NULL; |
fd7b9f7b TH |
704 | goto out_unlock; |
705 | } | |
324a56e1 TH |
706 | kernfs_get(kn); |
707 | dentry->d_fsdata = kn; | |
fd7b9f7b TH |
708 | |
709 | /* attach dentry and inode */ | |
c637b8ac | 710 | inode = kernfs_get_inode(dir->i_sb, kn); |
fd7b9f7b TH |
711 | if (!inode) { |
712 | ret = ERR_PTR(-ENOMEM); | |
713 | goto out_unlock; | |
714 | } | |
715 | ||
716 | /* instantiate and hash dentry */ | |
717 | ret = d_materialise_unique(dentry, inode); | |
718 | out_unlock: | |
a797bfc3 | 719 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
720 | return ret; |
721 | } | |
722 | ||
80b9bbef TH |
723 | static int kernfs_iop_mkdir(struct inode *dir, struct dentry *dentry, |
724 | umode_t mode) | |
725 | { | |
726 | struct kernfs_node *parent = dir->i_private; | |
727 | struct kernfs_dir_ops *kdops = kernfs_root(parent)->dir_ops; | |
728 | ||
729 | if (!kdops || !kdops->mkdir) | |
730 | return -EPERM; | |
731 | ||
732 | return kdops->mkdir(parent, dentry->d_name.name, mode); | |
733 | } | |
734 | ||
735 | static int kernfs_iop_rmdir(struct inode *dir, struct dentry *dentry) | |
736 | { | |
737 | struct kernfs_node *kn = dentry->d_fsdata; | |
738 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
739 | ||
740 | if (!kdops || !kdops->rmdir) | |
741 | return -EPERM; | |
742 | ||
743 | return kdops->rmdir(kn); | |
744 | } | |
745 | ||
746 | static int kernfs_iop_rename(struct inode *old_dir, struct dentry *old_dentry, | |
747 | struct inode *new_dir, struct dentry *new_dentry) | |
748 | { | |
749 | struct kernfs_node *kn = old_dentry->d_fsdata; | |
750 | struct kernfs_node *new_parent = new_dir->i_private; | |
751 | struct kernfs_dir_ops *kdops = kernfs_root(kn)->dir_ops; | |
752 | ||
753 | if (!kdops || !kdops->rename) | |
754 | return -EPERM; | |
755 | ||
756 | return kdops->rename(kn, new_parent, new_dentry->d_name.name); | |
757 | } | |
758 | ||
a797bfc3 | 759 | const struct inode_operations kernfs_dir_iops = { |
c637b8ac TH |
760 | .lookup = kernfs_iop_lookup, |
761 | .permission = kernfs_iop_permission, | |
762 | .setattr = kernfs_iop_setattr, | |
763 | .getattr = kernfs_iop_getattr, | |
764 | .setxattr = kernfs_iop_setxattr, | |
765 | .removexattr = kernfs_iop_removexattr, | |
766 | .getxattr = kernfs_iop_getxattr, | |
767 | .listxattr = kernfs_iop_listxattr, | |
80b9bbef TH |
768 | |
769 | .mkdir = kernfs_iop_mkdir, | |
770 | .rmdir = kernfs_iop_rmdir, | |
771 | .rename = kernfs_iop_rename, | |
fd7b9f7b TH |
772 | }; |
773 | ||
c637b8ac | 774 | static struct kernfs_node *kernfs_leftmost_descendant(struct kernfs_node *pos) |
fd7b9f7b | 775 | { |
324a56e1 | 776 | struct kernfs_node *last; |
fd7b9f7b TH |
777 | |
778 | while (true) { | |
779 | struct rb_node *rbn; | |
780 | ||
781 | last = pos; | |
782 | ||
df23fc39 | 783 | if (kernfs_type(pos) != KERNFS_DIR) |
fd7b9f7b TH |
784 | break; |
785 | ||
adc5e8b5 | 786 | rbn = rb_first(&pos->dir.children); |
fd7b9f7b TH |
787 | if (!rbn) |
788 | break; | |
789 | ||
324a56e1 | 790 | pos = rb_to_kn(rbn); |
fd7b9f7b TH |
791 | } |
792 | ||
793 | return last; | |
794 | } | |
795 | ||
796 | /** | |
c637b8ac | 797 | * kernfs_next_descendant_post - find the next descendant for post-order walk |
fd7b9f7b | 798 | * @pos: the current position (%NULL to initiate traversal) |
324a56e1 | 799 | * @root: kernfs_node whose descendants to walk |
fd7b9f7b TH |
800 | * |
801 | * Find the next descendant to visit for post-order traversal of @root's | |
802 | * descendants. @root is included in the iteration and the last node to be | |
803 | * visited. | |
804 | */ | |
c637b8ac TH |
805 | static struct kernfs_node *kernfs_next_descendant_post(struct kernfs_node *pos, |
806 | struct kernfs_node *root) | |
fd7b9f7b TH |
807 | { |
808 | struct rb_node *rbn; | |
809 | ||
a797bfc3 | 810 | lockdep_assert_held(&kernfs_mutex); |
fd7b9f7b TH |
811 | |
812 | /* if first iteration, visit leftmost descendant which may be root */ | |
813 | if (!pos) | |
c637b8ac | 814 | return kernfs_leftmost_descendant(root); |
fd7b9f7b TH |
815 | |
816 | /* if we visited @root, we're done */ | |
817 | if (pos == root) | |
818 | return NULL; | |
819 | ||
820 | /* if there's an unvisited sibling, visit its leftmost descendant */ | |
adc5e8b5 | 821 | rbn = rb_next(&pos->rb); |
fd7b9f7b | 822 | if (rbn) |
c637b8ac | 823 | return kernfs_leftmost_descendant(rb_to_kn(rbn)); |
fd7b9f7b TH |
824 | |
825 | /* no sibling left, visit parent */ | |
adc5e8b5 | 826 | return pos->parent; |
fd7b9f7b TH |
827 | } |
828 | ||
7653fe9d GKH |
829 | static void __kernfs_remove(struct kernfs_addrm_cxt *acxt, |
830 | struct kernfs_node *kn) | |
fd7b9f7b | 831 | { |
4f4b1b64 | 832 | struct kernfs_node *pos, *next; |
fd7b9f7b | 833 | |
ce9b499c GKH |
834 | if (!kn) |
835 | return; | |
836 | ||
c637b8ac | 837 | pr_debug("kernfs %s: removing\n", kn->name); |
fd7b9f7b | 838 | |
4f4b1b64 | 839 | next = NULL; |
fd7b9f7b | 840 | do { |
4f4b1b64 GKH |
841 | pos = next; |
842 | next = kernfs_next_descendant_post(pos, kn); | |
843 | if (pos) | |
844 | kernfs_remove_one(acxt, pos); | |
845 | } while (next); | |
fd7b9f7b TH |
846 | } |
847 | ||
848 | /** | |
324a56e1 TH |
849 | * kernfs_remove - remove a kernfs_node recursively |
850 | * @kn: the kernfs_node to remove | |
fd7b9f7b | 851 | * |
324a56e1 | 852 | * Remove @kn along with all its subdirectories and files. |
fd7b9f7b | 853 | */ |
324a56e1 | 854 | void kernfs_remove(struct kernfs_node *kn) |
fd7b9f7b | 855 | { |
7653fe9d GKH |
856 | struct kernfs_addrm_cxt acxt; |
857 | ||
858 | kernfs_addrm_start(&acxt); | |
859 | __kernfs_remove(&acxt, kn); | |
860 | kernfs_addrm_finish(&acxt); | |
fd7b9f7b TH |
861 | } |
862 | ||
863 | /** | |
324a56e1 TH |
864 | * kernfs_remove_by_name_ns - find a kernfs_node by name and remove it |
865 | * @parent: parent of the target | |
866 | * @name: name of the kernfs_node to remove | |
867 | * @ns: namespace tag of the kernfs_node to remove | |
fd7b9f7b | 868 | * |
324a56e1 TH |
869 | * Look for the kernfs_node with @name and @ns under @parent and remove it. |
870 | * Returns 0 on success, -ENOENT if such entry doesn't exist. | |
fd7b9f7b | 871 | */ |
324a56e1 | 872 | int kernfs_remove_by_name_ns(struct kernfs_node *parent, const char *name, |
fd7b9f7b TH |
873 | const void *ns) |
874 | { | |
7653fe9d | 875 | struct kernfs_addrm_cxt acxt; |
324a56e1 | 876 | struct kernfs_node *kn; |
fd7b9f7b | 877 | |
324a56e1 | 878 | if (!parent) { |
c637b8ac | 879 | WARN(1, KERN_WARNING "kernfs: can not remove '%s', no directory\n", |
fd7b9f7b TH |
880 | name); |
881 | return -ENOENT; | |
882 | } | |
883 | ||
7653fe9d | 884 | kernfs_addrm_start(&acxt); |
fd7b9f7b | 885 | |
324a56e1 TH |
886 | kn = kernfs_find_ns(parent, name, ns); |
887 | if (kn) | |
7653fe9d | 888 | __kernfs_remove(&acxt, kn); |
fd7b9f7b | 889 | |
7653fe9d | 890 | kernfs_addrm_finish(&acxt); |
fd7b9f7b | 891 | |
324a56e1 | 892 | if (kn) |
fd7b9f7b TH |
893 | return 0; |
894 | else | |
895 | return -ENOENT; | |
896 | } | |
897 | ||
898 | /** | |
899 | * kernfs_rename_ns - move and rename a kernfs_node | |
324a56e1 | 900 | * @kn: target node |
fd7b9f7b TH |
901 | * @new_parent: new parent to put @sd under |
902 | * @new_name: new name | |
903 | * @new_ns: new namespace tag | |
904 | */ | |
324a56e1 | 905 | int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent, |
fd7b9f7b TH |
906 | const char *new_name, const void *new_ns) |
907 | { | |
908 | int error; | |
909 | ||
798c75a0 GKH |
910 | mutex_lock(&kernfs_mutex); |
911 | ||
d0ae3d43 | 912 | error = -ENOENT; |
798c75a0 | 913 | if ((kn->flags | new_parent->flags) & KERNFS_REMOVED) |
d0ae3d43 TH |
914 | goto out; |
915 | ||
fd7b9f7b | 916 | error = 0; |
adc5e8b5 TH |
917 | if ((kn->parent == new_parent) && (kn->ns == new_ns) && |
918 | (strcmp(kn->name, new_name) == 0)) | |
798c75a0 | 919 | goto out; /* nothing to rename */ |
fd7b9f7b TH |
920 | |
921 | error = -EEXIST; | |
922 | if (kernfs_find_ns(new_parent, new_name, new_ns)) | |
798c75a0 | 923 | goto out; |
fd7b9f7b | 924 | |
324a56e1 | 925 | /* rename kernfs_node */ |
adc5e8b5 | 926 | if (strcmp(kn->name, new_name) != 0) { |
fd7b9f7b TH |
927 | error = -ENOMEM; |
928 | new_name = kstrdup(new_name, GFP_KERNEL); | |
929 | if (!new_name) | |
798c75a0 | 930 | goto out; |
fd7b9f7b | 931 | |
47a52e91 TH |
932 | if (kn->flags & KERNFS_STATIC_NAME) |
933 | kn->flags &= ~KERNFS_STATIC_NAME; | |
934 | else | |
935 | kfree(kn->name); | |
936 | ||
adc5e8b5 | 937 | kn->name = new_name; |
fd7b9f7b TH |
938 | } |
939 | ||
940 | /* | |
941 | * Move to the appropriate place in the appropriate directories rbtree. | |
942 | */ | |
c637b8ac | 943 | kernfs_unlink_sibling(kn); |
fd7b9f7b | 944 | kernfs_get(new_parent); |
adc5e8b5 TH |
945 | kernfs_put(kn->parent); |
946 | kn->ns = new_ns; | |
c637b8ac | 947 | kn->hash = kernfs_name_hash(kn->name, kn->ns); |
adc5e8b5 | 948 | kn->parent = new_parent; |
c637b8ac | 949 | kernfs_link_sibling(kn); |
fd7b9f7b TH |
950 | |
951 | error = 0; | |
798c75a0 | 952 | out: |
a797bfc3 | 953 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
954 | return error; |
955 | } | |
956 | ||
fd7b9f7b | 957 | /* Relationship between s_mode and the DT_xxx types */ |
324a56e1 | 958 | static inline unsigned char dt_type(struct kernfs_node *kn) |
fd7b9f7b | 959 | { |
adc5e8b5 | 960 | return (kn->mode >> 12) & 15; |
fd7b9f7b TH |
961 | } |
962 | ||
c637b8ac | 963 | static int kernfs_dir_fop_release(struct inode *inode, struct file *filp) |
fd7b9f7b TH |
964 | { |
965 | kernfs_put(filp->private_data); | |
966 | return 0; | |
967 | } | |
968 | ||
c637b8ac | 969 | static struct kernfs_node *kernfs_dir_pos(const void *ns, |
324a56e1 | 970 | struct kernfs_node *parent, loff_t hash, struct kernfs_node *pos) |
fd7b9f7b TH |
971 | { |
972 | if (pos) { | |
798c75a0 GKH |
973 | int valid = !(pos->flags & KERNFS_REMOVED) && |
974 | pos->parent == parent && hash == pos->hash; | |
fd7b9f7b TH |
975 | kernfs_put(pos); |
976 | if (!valid) | |
977 | pos = NULL; | |
978 | } | |
979 | if (!pos && (hash > 1) && (hash < INT_MAX)) { | |
adc5e8b5 | 980 | struct rb_node *node = parent->dir.children.rb_node; |
fd7b9f7b | 981 | while (node) { |
324a56e1 | 982 | pos = rb_to_kn(node); |
fd7b9f7b | 983 | |
adc5e8b5 | 984 | if (hash < pos->hash) |
fd7b9f7b | 985 | node = node->rb_left; |
adc5e8b5 | 986 | else if (hash > pos->hash) |
fd7b9f7b TH |
987 | node = node->rb_right; |
988 | else | |
989 | break; | |
990 | } | |
991 | } | |
992 | /* Skip over entries in the wrong namespace */ | |
adc5e8b5 TH |
993 | while (pos && pos->ns != ns) { |
994 | struct rb_node *node = rb_next(&pos->rb); | |
fd7b9f7b TH |
995 | if (!node) |
996 | pos = NULL; | |
997 | else | |
324a56e1 | 998 | pos = rb_to_kn(node); |
fd7b9f7b TH |
999 | } |
1000 | return pos; | |
1001 | } | |
1002 | ||
c637b8ac | 1003 | static struct kernfs_node *kernfs_dir_next_pos(const void *ns, |
324a56e1 | 1004 | struct kernfs_node *parent, ino_t ino, struct kernfs_node *pos) |
fd7b9f7b | 1005 | { |
c637b8ac | 1006 | pos = kernfs_dir_pos(ns, parent, ino, pos); |
fd7b9f7b TH |
1007 | if (pos) |
1008 | do { | |
adc5e8b5 | 1009 | struct rb_node *node = rb_next(&pos->rb); |
fd7b9f7b TH |
1010 | if (!node) |
1011 | pos = NULL; | |
1012 | else | |
324a56e1 | 1013 | pos = rb_to_kn(node); |
adc5e8b5 | 1014 | } while (pos && pos->ns != ns); |
fd7b9f7b TH |
1015 | return pos; |
1016 | } | |
1017 | ||
c637b8ac | 1018 | static int kernfs_fop_readdir(struct file *file, struct dir_context *ctx) |
fd7b9f7b TH |
1019 | { |
1020 | struct dentry *dentry = file->f_path.dentry; | |
324a56e1 TH |
1021 | struct kernfs_node *parent = dentry->d_fsdata; |
1022 | struct kernfs_node *pos = file->private_data; | |
fd7b9f7b TH |
1023 | const void *ns = NULL; |
1024 | ||
1025 | if (!dir_emit_dots(file, ctx)) | |
1026 | return 0; | |
a797bfc3 | 1027 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1028 | |
324a56e1 | 1029 | if (kernfs_ns_enabled(parent)) |
c525aadd | 1030 | ns = kernfs_info(dentry->d_sb)->ns; |
fd7b9f7b | 1031 | |
c637b8ac | 1032 | for (pos = kernfs_dir_pos(ns, parent, ctx->pos, pos); |
fd7b9f7b | 1033 | pos; |
c637b8ac | 1034 | pos = kernfs_dir_next_pos(ns, parent, ctx->pos, pos)) { |
adc5e8b5 | 1035 | const char *name = pos->name; |
fd7b9f7b TH |
1036 | unsigned int type = dt_type(pos); |
1037 | int len = strlen(name); | |
adc5e8b5 | 1038 | ino_t ino = pos->ino; |
fd7b9f7b | 1039 | |
adc5e8b5 | 1040 | ctx->pos = pos->hash; |
fd7b9f7b TH |
1041 | file->private_data = pos; |
1042 | kernfs_get(pos); | |
1043 | ||
a797bfc3 | 1044 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1045 | if (!dir_emit(ctx, name, len, ino, type)) |
1046 | return 0; | |
a797bfc3 | 1047 | mutex_lock(&kernfs_mutex); |
fd7b9f7b | 1048 | } |
a797bfc3 | 1049 | mutex_unlock(&kernfs_mutex); |
fd7b9f7b TH |
1050 | file->private_data = NULL; |
1051 | ctx->pos = INT_MAX; | |
1052 | return 0; | |
1053 | } | |
1054 | ||
c637b8ac TH |
1055 | static loff_t kernfs_dir_fop_llseek(struct file *file, loff_t offset, |
1056 | int whence) | |
fd7b9f7b TH |
1057 | { |
1058 | struct inode *inode = file_inode(file); | |
1059 | loff_t ret; | |
1060 | ||
1061 | mutex_lock(&inode->i_mutex); | |
1062 | ret = generic_file_llseek(file, offset, whence); | |
1063 | mutex_unlock(&inode->i_mutex); | |
1064 | ||
1065 | return ret; | |
1066 | } | |
1067 | ||
a797bfc3 | 1068 | const struct file_operations kernfs_dir_fops = { |
fd7b9f7b | 1069 | .read = generic_read_dir, |
c637b8ac TH |
1070 | .iterate = kernfs_fop_readdir, |
1071 | .release = kernfs_dir_fop_release, | |
1072 | .llseek = kernfs_dir_fop_llseek, | |
fd7b9f7b | 1073 | }; |