]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | File: fs/xattr.c | |
3 | ||
4 | Extended attribute handling. | |
5 | ||
6 | Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org> | |
7 | Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com> | |
8 | Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com> | |
9 | */ | |
10 | #include <linux/fs.h> | |
11 | #include <linux/slab.h> | |
1da177e4 LT |
12 | #include <linux/file.h> |
13 | #include <linux/xattr.h> | |
14 | #include <linux/namei.h> | |
15 | #include <linux/security.h> | |
16 | #include <linux/syscalls.h> | |
17 | #include <linux/module.h> | |
0eeca283 | 18 | #include <linux/fsnotify.h> |
73241ccc | 19 | #include <linux/audit.h> |
1da177e4 LT |
20 | #include <asm/uaccess.h> |
21 | ||
5be196e5 | 22 | |
e0ad7b07 | 23 | /* |
24 | * Check permissions for extended attribute access. This is a bit complicated | |
25 | * because different namespaces have very different rules. | |
26 | */ | |
27 | static int | |
28 | xattr_permission(struct inode *inode, const char *name, int mask) | |
29 | { | |
30 | /* | |
31 | * We can never set or remove an extended attribute on a read-only | |
32 | * filesystem or on an immutable / append-only inode. | |
33 | */ | |
34 | if (mask & MAY_WRITE) { | |
35 | if (IS_RDONLY(inode)) | |
36 | return -EROFS; | |
37 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
38 | return -EPERM; | |
39 | } | |
40 | ||
41 | /* | |
42 | * No restriction for security.* and system.* from the VFS. Decision | |
43 | * on these is left to the underlying filesystem / security module. | |
44 | */ | |
45 | if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) || | |
46 | !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) | |
47 | return 0; | |
48 | ||
49 | /* | |
f1f2d871 | 50 | * The trusted.* namespace can only be accessed by a privileged user. |
e0ad7b07 | 51 | */ |
52 | if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) | |
53 | return (capable(CAP_SYS_ADMIN) ? 0 : -EPERM); | |
54 | ||
f1f2d871 AG |
55 | /* In user.* namespace, only regular files and directories can have |
56 | * extended attributes. For sticky directories, only the owner and | |
57 | * privileged user can write attributes. | |
58 | */ | |
e0ad7b07 | 59 | if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) { |
f1f2d871 AG |
60 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) |
61 | return -EPERM; | |
62 | if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) && | |
3bd858ab | 63 | (mask & MAY_WRITE) && !is_owner_or_cap(inode)) |
e0ad7b07 | 64 | return -EPERM; |
65 | } | |
66 | ||
67 | return permission(inode, mask, NULL); | |
68 | } | |
69 | ||
5be196e5 CH |
70 | int |
71 | vfs_setxattr(struct dentry *dentry, char *name, void *value, | |
72 | size_t size, int flags) | |
73 | { | |
74 | struct inode *inode = dentry->d_inode; | |
75 | int error; | |
76 | ||
e0ad7b07 | 77 | error = xattr_permission(inode, name, MAY_WRITE); |
78 | if (error) | |
79 | return error; | |
80 | ||
5be196e5 CH |
81 | mutex_lock(&inode->i_mutex); |
82 | error = security_inode_setxattr(dentry, name, value, size, flags); | |
83 | if (error) | |
84 | goto out; | |
85 | error = -EOPNOTSUPP; | |
86 | if (inode->i_op->setxattr) { | |
87 | error = inode->i_op->setxattr(dentry, name, value, size, flags); | |
88 | if (!error) { | |
89 | fsnotify_xattr(dentry); | |
90 | security_inode_post_setxattr(dentry, name, value, | |
91 | size, flags); | |
92 | } | |
93 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
e0ad7b07 | 94 | XATTR_SECURITY_PREFIX_LEN)) { |
95 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; | |
5be196e5 CH |
96 | error = security_inode_setsecurity(inode, suffix, value, |
97 | size, flags); | |
98 | if (!error) | |
99 | fsnotify_xattr(dentry); | |
100 | } | |
101 | out: | |
102 | mutex_unlock(&inode->i_mutex); | |
103 | return error; | |
104 | } | |
105 | EXPORT_SYMBOL_GPL(vfs_setxattr); | |
106 | ||
42492594 DQ |
107 | ssize_t |
108 | xattr_getsecurity(struct inode *inode, const char *name, void *value, | |
109 | size_t size) | |
110 | { | |
111 | void *buffer = NULL; | |
112 | ssize_t len; | |
113 | ||
114 | if (!value || !size) { | |
115 | len = security_inode_getsecurity(inode, name, &buffer, false); | |
116 | goto out_noalloc; | |
117 | } | |
118 | ||
119 | len = security_inode_getsecurity(inode, name, &buffer, true); | |
120 | if (len < 0) | |
121 | return len; | |
122 | if (size < len) { | |
123 | len = -ERANGE; | |
124 | goto out; | |
125 | } | |
126 | memcpy(value, buffer, len); | |
127 | out: | |
128 | security_release_secctx(buffer, len); | |
129 | out_noalloc: | |
130 | return len; | |
131 | } | |
132 | EXPORT_SYMBOL_GPL(xattr_getsecurity); | |
133 | ||
5be196e5 CH |
134 | ssize_t |
135 | vfs_getxattr(struct dentry *dentry, char *name, void *value, size_t size) | |
136 | { | |
137 | struct inode *inode = dentry->d_inode; | |
138 | int error; | |
139 | ||
e0ad7b07 | 140 | error = xattr_permission(inode, name, MAY_READ); |
141 | if (error) | |
142 | return error; | |
143 | ||
5be196e5 CH |
144 | error = security_inode_getxattr(dentry, name); |
145 | if (error) | |
146 | return error; | |
147 | ||
148 | if (inode->i_op->getxattr) | |
149 | error = inode->i_op->getxattr(dentry, name, value, size); | |
150 | else | |
151 | error = -EOPNOTSUPP; | |
152 | ||
153 | if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
e0ad7b07 | 154 | XATTR_SECURITY_PREFIX_LEN)) { |
155 | const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; | |
42492594 | 156 | int ret = xattr_getsecurity(inode, suffix, value, size); |
5be196e5 CH |
157 | /* |
158 | * Only overwrite the return value if a security module | |
159 | * is actually active. | |
160 | */ | |
161 | if (ret != -EOPNOTSUPP) | |
162 | error = ret; | |
163 | } | |
164 | ||
165 | return error; | |
166 | } | |
167 | EXPORT_SYMBOL_GPL(vfs_getxattr); | |
168 | ||
659564c8 BN |
169 | ssize_t |
170 | vfs_listxattr(struct dentry *d, char *list, size_t size) | |
171 | { | |
172 | ssize_t error; | |
173 | ||
174 | error = security_inode_listxattr(d); | |
175 | if (error) | |
176 | return error; | |
177 | error = -EOPNOTSUPP; | |
178 | if (d->d_inode->i_op && d->d_inode->i_op->listxattr) { | |
179 | error = d->d_inode->i_op->listxattr(d, list, size); | |
180 | } else { | |
181 | error = security_inode_listsecurity(d->d_inode, list, size); | |
182 | if (size && error > size) | |
183 | error = -ERANGE; | |
184 | } | |
185 | return error; | |
186 | } | |
187 | EXPORT_SYMBOL_GPL(vfs_listxattr); | |
188 | ||
5be196e5 CH |
189 | int |
190 | vfs_removexattr(struct dentry *dentry, char *name) | |
191 | { | |
192 | struct inode *inode = dentry->d_inode; | |
193 | int error; | |
194 | ||
195 | if (!inode->i_op->removexattr) | |
196 | return -EOPNOTSUPP; | |
197 | ||
e0ad7b07 | 198 | error = xattr_permission(inode, name, MAY_WRITE); |
199 | if (error) | |
200 | return error; | |
201 | ||
5be196e5 CH |
202 | error = security_inode_removexattr(dentry, name); |
203 | if (error) | |
204 | return error; | |
205 | ||
206 | mutex_lock(&inode->i_mutex); | |
207 | error = inode->i_op->removexattr(dentry, name); | |
208 | mutex_unlock(&inode->i_mutex); | |
209 | ||
210 | if (!error) | |
211 | fsnotify_xattr(dentry); | |
212 | return error; | |
213 | } | |
214 | EXPORT_SYMBOL_GPL(vfs_removexattr); | |
215 | ||
216 | ||
1da177e4 LT |
217 | /* |
218 | * Extended attribute SET operations | |
219 | */ | |
220 | static long | |
221 | setxattr(struct dentry *d, char __user *name, void __user *value, | |
222 | size_t size, int flags) | |
223 | { | |
224 | int error; | |
225 | void *kvalue = NULL; | |
226 | char kname[XATTR_NAME_MAX + 1]; | |
227 | ||
228 | if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) | |
229 | return -EINVAL; | |
230 | ||
231 | error = strncpy_from_user(kname, name, sizeof(kname)); | |
232 | if (error == 0 || error == sizeof(kname)) | |
233 | error = -ERANGE; | |
234 | if (error < 0) | |
235 | return error; | |
236 | ||
237 | if (size) { | |
238 | if (size > XATTR_SIZE_MAX) | |
239 | return -E2BIG; | |
240 | kvalue = kmalloc(size, GFP_KERNEL); | |
241 | if (!kvalue) | |
242 | return -ENOMEM; | |
243 | if (copy_from_user(kvalue, value, size)) { | |
244 | kfree(kvalue); | |
245 | return -EFAULT; | |
246 | } | |
247 | } | |
248 | ||
5be196e5 | 249 | error = vfs_setxattr(d, kname, kvalue, size, flags); |
f99d49ad | 250 | kfree(kvalue); |
1da177e4 LT |
251 | return error; |
252 | } | |
253 | ||
254 | asmlinkage long | |
255 | sys_setxattr(char __user *path, char __user *name, void __user *value, | |
256 | size_t size, int flags) | |
257 | { | |
258 | struct nameidata nd; | |
259 | int error; | |
260 | ||
261 | error = user_path_walk(path, &nd); | |
262 | if (error) | |
263 | return error; | |
264 | error = setxattr(nd.dentry, name, value, size, flags); | |
265 | path_release(&nd); | |
266 | return error; | |
267 | } | |
268 | ||
269 | asmlinkage long | |
270 | sys_lsetxattr(char __user *path, char __user *name, void __user *value, | |
271 | size_t size, int flags) | |
272 | { | |
273 | struct nameidata nd; | |
274 | int error; | |
275 | ||
276 | error = user_path_walk_link(path, &nd); | |
277 | if (error) | |
278 | return error; | |
279 | error = setxattr(nd.dentry, name, value, size, flags); | |
280 | path_release(&nd); | |
281 | return error; | |
282 | } | |
283 | ||
284 | asmlinkage long | |
285 | sys_fsetxattr(int fd, char __user *name, void __user *value, | |
286 | size_t size, int flags) | |
287 | { | |
288 | struct file *f; | |
73241ccc | 289 | struct dentry *dentry; |
1da177e4 LT |
290 | int error = -EBADF; |
291 | ||
292 | f = fget(fd); | |
293 | if (!f) | |
294 | return error; | |
0f7fc9e4 | 295 | dentry = f->f_path.dentry; |
5a190ae6 | 296 | audit_inode(NULL, dentry); |
73241ccc | 297 | error = setxattr(dentry, name, value, size, flags); |
1da177e4 LT |
298 | fput(f); |
299 | return error; | |
300 | } | |
301 | ||
302 | /* | |
303 | * Extended attribute GET operations | |
304 | */ | |
305 | static ssize_t | |
306 | getxattr(struct dentry *d, char __user *name, void __user *value, size_t size) | |
307 | { | |
308 | ssize_t error; | |
309 | void *kvalue = NULL; | |
310 | char kname[XATTR_NAME_MAX + 1]; | |
311 | ||
312 | error = strncpy_from_user(kname, name, sizeof(kname)); | |
313 | if (error == 0 || error == sizeof(kname)) | |
314 | error = -ERANGE; | |
315 | if (error < 0) | |
316 | return error; | |
317 | ||
318 | if (size) { | |
319 | if (size > XATTR_SIZE_MAX) | |
320 | size = XATTR_SIZE_MAX; | |
d381d8a9 | 321 | kvalue = kzalloc(size, GFP_KERNEL); |
1da177e4 LT |
322 | if (!kvalue) |
323 | return -ENOMEM; | |
324 | } | |
325 | ||
5be196e5 | 326 | error = vfs_getxattr(d, kname, kvalue, size); |
f549d6c1 SS |
327 | if (error > 0) { |
328 | if (size && copy_to_user(value, kvalue, error)) | |
329 | error = -EFAULT; | |
330 | } else if (error == -ERANGE && size >= XATTR_SIZE_MAX) { | |
331 | /* The file system tried to returned a value bigger | |
332 | than XATTR_SIZE_MAX bytes. Not possible. */ | |
333 | error = -E2BIG; | |
1da177e4 | 334 | } |
f99d49ad | 335 | kfree(kvalue); |
1da177e4 LT |
336 | return error; |
337 | } | |
338 | ||
339 | asmlinkage ssize_t | |
340 | sys_getxattr(char __user *path, char __user *name, void __user *value, | |
341 | size_t size) | |
342 | { | |
343 | struct nameidata nd; | |
344 | ssize_t error; | |
345 | ||
346 | error = user_path_walk(path, &nd); | |
347 | if (error) | |
348 | return error; | |
349 | error = getxattr(nd.dentry, name, value, size); | |
350 | path_release(&nd); | |
351 | return error; | |
352 | } | |
353 | ||
354 | asmlinkage ssize_t | |
355 | sys_lgetxattr(char __user *path, char __user *name, void __user *value, | |
356 | size_t size) | |
357 | { | |
358 | struct nameidata nd; | |
359 | ssize_t error; | |
360 | ||
361 | error = user_path_walk_link(path, &nd); | |
362 | if (error) | |
363 | return error; | |
364 | error = getxattr(nd.dentry, name, value, size); | |
365 | path_release(&nd); | |
366 | return error; | |
367 | } | |
368 | ||
369 | asmlinkage ssize_t | |
370 | sys_fgetxattr(int fd, char __user *name, void __user *value, size_t size) | |
371 | { | |
372 | struct file *f; | |
373 | ssize_t error = -EBADF; | |
374 | ||
375 | f = fget(fd); | |
376 | if (!f) | |
377 | return error; | |
5a190ae6 | 378 | audit_inode(NULL, f->f_path.dentry); |
0f7fc9e4 | 379 | error = getxattr(f->f_path.dentry, name, value, size); |
1da177e4 LT |
380 | fput(f); |
381 | return error; | |
382 | } | |
383 | ||
384 | /* | |
385 | * Extended attribute LIST operations | |
386 | */ | |
387 | static ssize_t | |
388 | listxattr(struct dentry *d, char __user *list, size_t size) | |
389 | { | |
390 | ssize_t error; | |
391 | char *klist = NULL; | |
392 | ||
393 | if (size) { | |
394 | if (size > XATTR_LIST_MAX) | |
395 | size = XATTR_LIST_MAX; | |
396 | klist = kmalloc(size, GFP_KERNEL); | |
397 | if (!klist) | |
398 | return -ENOMEM; | |
399 | } | |
400 | ||
659564c8 | 401 | error = vfs_listxattr(d, klist, size); |
f549d6c1 SS |
402 | if (error > 0) { |
403 | if (size && copy_to_user(list, klist, error)) | |
404 | error = -EFAULT; | |
405 | } else if (error == -ERANGE && size >= XATTR_LIST_MAX) { | |
406 | /* The file system tried to returned a list bigger | |
407 | than XATTR_LIST_MAX bytes. Not possible. */ | |
408 | error = -E2BIG; | |
1da177e4 | 409 | } |
f99d49ad | 410 | kfree(klist); |
1da177e4 LT |
411 | return error; |
412 | } | |
413 | ||
414 | asmlinkage ssize_t | |
415 | sys_listxattr(char __user *path, char __user *list, size_t size) | |
416 | { | |
417 | struct nameidata nd; | |
418 | ssize_t error; | |
419 | ||
420 | error = user_path_walk(path, &nd); | |
421 | if (error) | |
422 | return error; | |
423 | error = listxattr(nd.dentry, list, size); | |
424 | path_release(&nd); | |
425 | return error; | |
426 | } | |
427 | ||
428 | asmlinkage ssize_t | |
429 | sys_llistxattr(char __user *path, char __user *list, size_t size) | |
430 | { | |
431 | struct nameidata nd; | |
432 | ssize_t error; | |
433 | ||
434 | error = user_path_walk_link(path, &nd); | |
435 | if (error) | |
436 | return error; | |
437 | error = listxattr(nd.dentry, list, size); | |
438 | path_release(&nd); | |
439 | return error; | |
440 | } | |
441 | ||
442 | asmlinkage ssize_t | |
443 | sys_flistxattr(int fd, char __user *list, size_t size) | |
444 | { | |
445 | struct file *f; | |
446 | ssize_t error = -EBADF; | |
447 | ||
448 | f = fget(fd); | |
449 | if (!f) | |
450 | return error; | |
5a190ae6 | 451 | audit_inode(NULL, f->f_path.dentry); |
0f7fc9e4 | 452 | error = listxattr(f->f_path.dentry, list, size); |
1da177e4 LT |
453 | fput(f); |
454 | return error; | |
455 | } | |
456 | ||
457 | /* | |
458 | * Extended attribute REMOVE operations | |
459 | */ | |
460 | static long | |
461 | removexattr(struct dentry *d, char __user *name) | |
462 | { | |
463 | int error; | |
464 | char kname[XATTR_NAME_MAX + 1]; | |
465 | ||
466 | error = strncpy_from_user(kname, name, sizeof(kname)); | |
467 | if (error == 0 || error == sizeof(kname)) | |
468 | error = -ERANGE; | |
469 | if (error < 0) | |
470 | return error; | |
471 | ||
5be196e5 | 472 | return vfs_removexattr(d, kname); |
1da177e4 LT |
473 | } |
474 | ||
475 | asmlinkage long | |
476 | sys_removexattr(char __user *path, char __user *name) | |
477 | { | |
478 | struct nameidata nd; | |
479 | int error; | |
480 | ||
481 | error = user_path_walk(path, &nd); | |
482 | if (error) | |
483 | return error; | |
484 | error = removexattr(nd.dentry, name); | |
485 | path_release(&nd); | |
486 | return error; | |
487 | } | |
488 | ||
489 | asmlinkage long | |
490 | sys_lremovexattr(char __user *path, char __user *name) | |
491 | { | |
492 | struct nameidata nd; | |
493 | int error; | |
494 | ||
495 | error = user_path_walk_link(path, &nd); | |
496 | if (error) | |
497 | return error; | |
498 | error = removexattr(nd.dentry, name); | |
499 | path_release(&nd); | |
500 | return error; | |
501 | } | |
502 | ||
503 | asmlinkage long | |
504 | sys_fremovexattr(int fd, char __user *name) | |
505 | { | |
506 | struct file *f; | |
73241ccc | 507 | struct dentry *dentry; |
1da177e4 LT |
508 | int error = -EBADF; |
509 | ||
510 | f = fget(fd); | |
511 | if (!f) | |
512 | return error; | |
0f7fc9e4 | 513 | dentry = f->f_path.dentry; |
5a190ae6 | 514 | audit_inode(NULL, dentry); |
73241ccc | 515 | error = removexattr(dentry, name); |
1da177e4 LT |
516 | fput(f); |
517 | return error; | |
518 | } | |
519 | ||
520 | ||
521 | static const char * | |
522 | strcmp_prefix(const char *a, const char *a_prefix) | |
523 | { | |
524 | while (*a_prefix && *a == *a_prefix) { | |
525 | a++; | |
526 | a_prefix++; | |
527 | } | |
528 | return *a_prefix ? NULL : a; | |
529 | } | |
530 | ||
531 | /* | |
532 | * In order to implement different sets of xattr operations for each xattr | |
533 | * prefix with the generic xattr API, a filesystem should create a | |
534 | * null-terminated array of struct xattr_handler (one for each prefix) and | |
535 | * hang a pointer to it off of the s_xattr field of the superblock. | |
536 | * | |
537 | * The generic_fooxattr() functions will use this list to dispatch xattr | |
538 | * operations to the correct xattr_handler. | |
539 | */ | |
540 | #define for_each_xattr_handler(handlers, handler) \ | |
541 | for ((handler) = *(handlers)++; \ | |
542 | (handler) != NULL; \ | |
543 | (handler) = *(handlers)++) | |
544 | ||
545 | /* | |
546 | * Find the xattr_handler with the matching prefix. | |
547 | */ | |
548 | static struct xattr_handler * | |
549 | xattr_resolve_name(struct xattr_handler **handlers, const char **name) | |
550 | { | |
551 | struct xattr_handler *handler; | |
552 | ||
553 | if (!*name) | |
554 | return NULL; | |
555 | ||
556 | for_each_xattr_handler(handlers, handler) { | |
557 | const char *n = strcmp_prefix(*name, handler->prefix); | |
558 | if (n) { | |
559 | *name = n; | |
560 | break; | |
561 | } | |
562 | } | |
563 | return handler; | |
564 | } | |
565 | ||
566 | /* | |
567 | * Find the handler for the prefix and dispatch its get() operation. | |
568 | */ | |
569 | ssize_t | |
570 | generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size) | |
571 | { | |
572 | struct xattr_handler *handler; | |
573 | struct inode *inode = dentry->d_inode; | |
574 | ||
575 | handler = xattr_resolve_name(inode->i_sb->s_xattr, &name); | |
576 | if (!handler) | |
577 | return -EOPNOTSUPP; | |
578 | return handler->get(inode, name, buffer, size); | |
579 | } | |
580 | ||
581 | /* | |
582 | * Combine the results of the list() operation from every xattr_handler in the | |
583 | * list. | |
584 | */ | |
585 | ssize_t | |
586 | generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) | |
587 | { | |
588 | struct inode *inode = dentry->d_inode; | |
589 | struct xattr_handler *handler, **handlers = inode->i_sb->s_xattr; | |
590 | unsigned int size = 0; | |
591 | ||
592 | if (!buffer) { | |
593 | for_each_xattr_handler(handlers, handler) | |
594 | size += handler->list(inode, NULL, 0, NULL, 0); | |
595 | } else { | |
596 | char *buf = buffer; | |
597 | ||
598 | for_each_xattr_handler(handlers, handler) { | |
599 | size = handler->list(inode, buf, buffer_size, NULL, 0); | |
600 | if (size > buffer_size) | |
601 | return -ERANGE; | |
602 | buf += size; | |
603 | buffer_size -= size; | |
604 | } | |
605 | size = buf - buffer; | |
606 | } | |
607 | return size; | |
608 | } | |
609 | ||
610 | /* | |
611 | * Find the handler for the prefix and dispatch its set() operation. | |
612 | */ | |
613 | int | |
614 | generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) | |
615 | { | |
616 | struct xattr_handler *handler; | |
617 | struct inode *inode = dentry->d_inode; | |
618 | ||
619 | if (size == 0) | |
620 | value = ""; /* empty EA, do not remove */ | |
621 | handler = xattr_resolve_name(inode->i_sb->s_xattr, &name); | |
622 | if (!handler) | |
623 | return -EOPNOTSUPP; | |
624 | return handler->set(inode, name, value, size, flags); | |
625 | } | |
626 | ||
627 | /* | |
628 | * Find the handler for the prefix and dispatch its set() operation to remove | |
629 | * any associated extended attribute. | |
630 | */ | |
631 | int | |
632 | generic_removexattr(struct dentry *dentry, const char *name) | |
633 | { | |
634 | struct xattr_handler *handler; | |
635 | struct inode *inode = dentry->d_inode; | |
636 | ||
637 | handler = xattr_resolve_name(inode->i_sb->s_xattr, &name); | |
638 | if (!handler) | |
639 | return -EOPNOTSUPP; | |
640 | return handler->set(inode, name, NULL, 0, XATTR_REPLACE); | |
641 | } | |
642 | ||
643 | EXPORT_SYMBOL(generic_getxattr); | |
644 | EXPORT_SYMBOL(generic_listxattr); | |
645 | EXPORT_SYMBOL(generic_setxattr); | |
646 | EXPORT_SYMBOL(generic_removexattr); |