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