Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-only
2 : /*
3 : File: fs/xattr.c
4 :
5 : Extended attribute handling.
6 :
7 : Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
8 : Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
9 : Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
10 : */
11 : #include <linux/fs.h>
12 : #include <linux/filelock.h>
13 : #include <linux/slab.h>
14 : #include <linux/file.h>
15 : #include <linux/xattr.h>
16 : #include <linux/mount.h>
17 : #include <linux/namei.h>
18 : #include <linux/security.h>
19 : #include <linux/evm.h>
20 : #include <linux/syscalls.h>
21 : #include <linux/export.h>
22 : #include <linux/fsnotify.h>
23 : #include <linux/audit.h>
24 : #include <linux/vmalloc.h>
25 : #include <linux/posix_acl_xattr.h>
26 :
27 : #include <linux/uaccess.h>
28 :
29 : #include "internal.h"
30 :
31 : static const char *
32 : strcmp_prefix(const char *a, const char *a_prefix)
33 : {
34 0 : while (*a_prefix && *a == *a_prefix) {
35 0 : a++;
36 0 : a_prefix++;
37 : }
38 0 : return *a_prefix ? NULL : a;
39 : }
40 :
41 : /*
42 : * In order to implement different sets of xattr operations for each xattr
43 : * prefix, a filesystem should create a null-terminated array of struct
44 : * xattr_handler (one for each prefix) and hang a pointer to it off of the
45 : * s_xattr field of the superblock.
46 : */
47 : #define for_each_xattr_handler(handlers, handler) \
48 : if (handlers) \
49 : for ((handler) = *(handlers)++; \
50 : (handler) != NULL; \
51 : (handler) = *(handlers)++)
52 :
53 : /*
54 : * Find the xattr_handler with the matching prefix.
55 : */
56 : static const struct xattr_handler *
57 0 : xattr_resolve_name(struct inode *inode, const char **name)
58 : {
59 0 : const struct xattr_handler **handlers = inode->i_sb->s_xattr;
60 : const struct xattr_handler *handler;
61 :
62 0 : if (!(inode->i_opflags & IOP_XATTR)) {
63 0 : if (unlikely(is_bad_inode(inode)))
64 : return ERR_PTR(-EIO);
65 0 : return ERR_PTR(-EOPNOTSUPP);
66 : }
67 0 : for_each_xattr_handler(handlers, handler) {
68 : const char *n;
69 :
70 0 : n = strcmp_prefix(*name, xattr_prefix(handler));
71 0 : if (n) {
72 0 : if (!handler->prefix ^ !*n) {
73 0 : if (*n)
74 0 : continue;
75 : return ERR_PTR(-EINVAL);
76 : }
77 0 : *name = n;
78 0 : return handler;
79 : }
80 : }
81 : return ERR_PTR(-EOPNOTSUPP);
82 : }
83 :
84 : /**
85 : * may_write_xattr - check whether inode allows writing xattr
86 : * @idmap: idmap of the mount the inode was found from
87 : * @inode: the inode on which to set an xattr
88 : *
89 : * Check whether the inode allows writing xattrs. Specifically, we can never
90 : * set or remove an extended attribute on a read-only filesystem or on an
91 : * immutable / append-only inode.
92 : *
93 : * We also need to ensure that the inode has a mapping in the mount to
94 : * not risk writing back invalid i_{g,u}id values.
95 : *
96 : * Return: On success zero is returned. On error a negative errno is returned.
97 : */
98 0 : int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode)
99 : {
100 0 : if (IS_IMMUTABLE(inode))
101 : return -EPERM;
102 0 : if (IS_APPEND(inode))
103 : return -EPERM;
104 0 : if (HAS_UNMAPPED_ID(idmap, inode))
105 : return -EPERM;
106 0 : return 0;
107 : }
108 :
109 : /*
110 : * Check permissions for extended attribute access. This is a bit complicated
111 : * because different namespaces have very different rules.
112 : */
113 : static int
114 0 : xattr_permission(struct mnt_idmap *idmap, struct inode *inode,
115 : const char *name, int mask)
116 : {
117 0 : if (mask & MAY_WRITE) {
118 : int ret;
119 :
120 0 : ret = may_write_xattr(idmap, inode);
121 0 : if (ret)
122 : return ret;
123 : }
124 :
125 : /*
126 : * No restriction for security.* and system.* from the VFS. Decision
127 : * on these is left to the underlying filesystem / security module.
128 : */
129 0 : if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) ||
130 0 : !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
131 : return 0;
132 :
133 : /*
134 : * The trusted.* namespace can only be accessed by privileged users.
135 : */
136 0 : if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) {
137 0 : if (!capable(CAP_SYS_ADMIN))
138 0 : return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
139 : return 0;
140 : }
141 :
142 : /*
143 : * In the user.* namespace, only regular files and directories can have
144 : * extended attributes. For sticky directories, only the owner and
145 : * privileged users can write attributes.
146 : */
147 0 : if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) {
148 0 : if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
149 0 : return (mask & MAY_WRITE) ? -EPERM : -ENODATA;
150 0 : if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) &&
151 0 : (mask & MAY_WRITE) &&
152 0 : !inode_owner_or_capable(idmap, inode))
153 : return -EPERM;
154 : }
155 :
156 0 : return inode_permission(idmap, inode, mask);
157 : }
158 :
159 : /*
160 : * Look for any handler that deals with the specified namespace.
161 : */
162 : int
163 0 : xattr_supported_namespace(struct inode *inode, const char *prefix)
164 : {
165 0 : const struct xattr_handler **handlers = inode->i_sb->s_xattr;
166 : const struct xattr_handler *handler;
167 : size_t preflen;
168 :
169 0 : if (!(inode->i_opflags & IOP_XATTR)) {
170 0 : if (unlikely(is_bad_inode(inode)))
171 : return -EIO;
172 0 : return -EOPNOTSUPP;
173 : }
174 :
175 0 : preflen = strlen(prefix);
176 :
177 0 : for_each_xattr_handler(handlers, handler) {
178 0 : if (!strncmp(xattr_prefix(handler), prefix, preflen))
179 : return 0;
180 : }
181 :
182 : return -EOPNOTSUPP;
183 : }
184 : EXPORT_SYMBOL(xattr_supported_namespace);
185 :
186 : int
187 0 : __vfs_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
188 : struct inode *inode, const char *name, const void *value,
189 : size_t size, int flags)
190 : {
191 : const struct xattr_handler *handler;
192 :
193 0 : if (is_posix_acl_xattr(name))
194 : return -EOPNOTSUPP;
195 :
196 0 : handler = xattr_resolve_name(inode, &name);
197 0 : if (IS_ERR(handler))
198 0 : return PTR_ERR(handler);
199 0 : if (!handler->set)
200 : return -EOPNOTSUPP;
201 0 : if (size == 0)
202 0 : value = ""; /* empty EA, do not remove */
203 0 : return handler->set(handler, idmap, dentry, inode, name, value,
204 : size, flags);
205 : }
206 : EXPORT_SYMBOL(__vfs_setxattr);
207 :
208 : /**
209 : * __vfs_setxattr_noperm - perform setxattr operation without performing
210 : * permission checks.
211 : *
212 : * @idmap: idmap of the mount the inode was found from
213 : * @dentry: object to perform setxattr on
214 : * @name: xattr name to set
215 : * @value: value to set @name to
216 : * @size: size of @value
217 : * @flags: flags to pass into filesystem operations
218 : *
219 : * returns the result of the internal setxattr or setsecurity operations.
220 : *
221 : * This function requires the caller to lock the inode's i_mutex before it
222 : * is executed. It also assumes that the caller will make the appropriate
223 : * permission checks.
224 : */
225 0 : int __vfs_setxattr_noperm(struct mnt_idmap *idmap,
226 : struct dentry *dentry, const char *name,
227 : const void *value, size_t size, int flags)
228 : {
229 0 : struct inode *inode = dentry->d_inode;
230 0 : int error = -EAGAIN;
231 0 : int issec = !strncmp(name, XATTR_SECURITY_PREFIX,
232 : XATTR_SECURITY_PREFIX_LEN);
233 :
234 0 : if (issec)
235 0 : inode->i_flags &= ~S_NOSEC;
236 0 : if (inode->i_opflags & IOP_XATTR) {
237 0 : error = __vfs_setxattr(idmap, dentry, inode, name, value,
238 : size, flags);
239 0 : if (!error) {
240 : fsnotify_xattr(dentry);
241 : security_inode_post_setxattr(dentry, name, value,
242 : size, flags);
243 : }
244 : } else {
245 0 : if (unlikely(is_bad_inode(inode)))
246 : return -EIO;
247 : }
248 0 : if (error == -EAGAIN) {
249 0 : error = -EOPNOTSUPP;
250 :
251 : if (issec) {
252 : const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
253 :
254 : error = security_inode_setsecurity(inode, suffix, value,
255 : size, flags);
256 : if (!error)
257 : fsnotify_xattr(dentry);
258 : }
259 : }
260 :
261 : return error;
262 : }
263 :
264 : /**
265 : * __vfs_setxattr_locked - set an extended attribute while holding the inode
266 : * lock
267 : *
268 : * @idmap: idmap of the mount of the target inode
269 : * @dentry: object to perform setxattr on
270 : * @name: xattr name to set
271 : * @value: value to set @name to
272 : * @size: size of @value
273 : * @flags: flags to pass into filesystem operations
274 : * @delegated_inode: on return, will contain an inode pointer that
275 : * a delegation was broken on, NULL if none.
276 : */
277 : int
278 0 : __vfs_setxattr_locked(struct mnt_idmap *idmap, struct dentry *dentry,
279 : const char *name, const void *value, size_t size,
280 : int flags, struct inode **delegated_inode)
281 : {
282 0 : struct inode *inode = dentry->d_inode;
283 : int error;
284 :
285 0 : error = xattr_permission(idmap, inode, name, MAY_WRITE);
286 0 : if (error)
287 : return error;
288 :
289 0 : error = security_inode_setxattr(idmap, dentry, name, value, size,
290 : flags);
291 0 : if (error)
292 : goto out;
293 :
294 0 : error = try_break_deleg(inode, delegated_inode);
295 0 : if (error)
296 : goto out;
297 :
298 0 : error = __vfs_setxattr_noperm(idmap, dentry, name, value,
299 : size, flags);
300 :
301 : out:
302 : return error;
303 : }
304 : EXPORT_SYMBOL_GPL(__vfs_setxattr_locked);
305 :
306 : int
307 0 : vfs_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
308 : const char *name, const void *value, size_t size, int flags)
309 : {
310 0 : struct inode *inode = dentry->d_inode;
311 0 : struct inode *delegated_inode = NULL;
312 0 : const void *orig_value = value;
313 : int error;
314 :
315 0 : if (size && strcmp(name, XATTR_NAME_CAPS) == 0) {
316 0 : error = cap_convert_nscap(idmap, dentry, &value, size);
317 0 : if (error < 0)
318 : return error;
319 0 : size = error;
320 : }
321 :
322 : retry_deleg:
323 0 : inode_lock(inode);
324 0 : error = __vfs_setxattr_locked(idmap, dentry, name, value, size,
325 : flags, &delegated_inode);
326 0 : inode_unlock(inode);
327 :
328 0 : if (delegated_inode) {
329 0 : error = break_deleg_wait(&delegated_inode);
330 0 : if (!error)
331 : goto retry_deleg;
332 : }
333 0 : if (value != orig_value)
334 0 : kfree(value);
335 :
336 : return error;
337 : }
338 : EXPORT_SYMBOL_GPL(vfs_setxattr);
339 :
340 : static ssize_t
341 0 : xattr_getsecurity(struct mnt_idmap *idmap, struct inode *inode,
342 : const char *name, void *value, size_t size)
343 : {
344 0 : void *buffer = NULL;
345 : ssize_t len;
346 :
347 0 : if (!value || !size) {
348 0 : len = security_inode_getsecurity(idmap, inode, name,
349 : &buffer, false);
350 0 : goto out_noalloc;
351 : }
352 :
353 0 : len = security_inode_getsecurity(idmap, inode, name, &buffer,
354 : true);
355 0 : if (len < 0)
356 : return len;
357 0 : if (size < len) {
358 : len = -ERANGE;
359 : goto out;
360 : }
361 0 : memcpy(value, buffer, len);
362 : out:
363 0 : kfree(buffer);
364 : out_noalloc:
365 : return len;
366 : }
367 :
368 : /*
369 : * vfs_getxattr_alloc - allocate memory, if necessary, before calling getxattr
370 : *
371 : * Allocate memory, if not already allocated, or re-allocate correct size,
372 : * before retrieving the extended attribute. The xattr value buffer should
373 : * always be freed by the caller, even on error.
374 : *
375 : * Returns the result of alloc, if failed, or the getxattr operation.
376 : */
377 : int
378 0 : vfs_getxattr_alloc(struct mnt_idmap *idmap, struct dentry *dentry,
379 : const char *name, char **xattr_value, size_t xattr_size,
380 : gfp_t flags)
381 : {
382 : const struct xattr_handler *handler;
383 0 : struct inode *inode = dentry->d_inode;
384 0 : char *value = *xattr_value;
385 : int error;
386 :
387 0 : error = xattr_permission(idmap, inode, name, MAY_READ);
388 0 : if (error)
389 : return error;
390 :
391 0 : handler = xattr_resolve_name(inode, &name);
392 0 : if (IS_ERR(handler))
393 0 : return PTR_ERR(handler);
394 0 : if (!handler->get)
395 : return -EOPNOTSUPP;
396 0 : error = handler->get(handler, dentry, inode, name, NULL, 0);
397 0 : if (error < 0)
398 : return error;
399 :
400 0 : if (!value || (error > xattr_size)) {
401 0 : value = krealloc(*xattr_value, error + 1, flags);
402 0 : if (!value)
403 : return -ENOMEM;
404 0 : memset(value, 0, error + 1);
405 : }
406 :
407 0 : error = handler->get(handler, dentry, inode, name, value, error);
408 0 : *xattr_value = value;
409 0 : return error;
410 : }
411 :
412 : ssize_t
413 0 : __vfs_getxattr(struct dentry *dentry, struct inode *inode, const char *name,
414 : void *value, size_t size)
415 : {
416 : const struct xattr_handler *handler;
417 :
418 0 : if (is_posix_acl_xattr(name))
419 : return -EOPNOTSUPP;
420 :
421 0 : handler = xattr_resolve_name(inode, &name);
422 0 : if (IS_ERR(handler))
423 0 : return PTR_ERR(handler);
424 0 : if (!handler->get)
425 : return -EOPNOTSUPP;
426 0 : return handler->get(handler, dentry, inode, name, value, size);
427 : }
428 : EXPORT_SYMBOL(__vfs_getxattr);
429 :
430 : ssize_t
431 0 : vfs_getxattr(struct mnt_idmap *idmap, struct dentry *dentry,
432 : const char *name, void *value, size_t size)
433 : {
434 0 : struct inode *inode = dentry->d_inode;
435 : int error;
436 :
437 0 : error = xattr_permission(idmap, inode, name, MAY_READ);
438 0 : if (error)
439 0 : return error;
440 :
441 0 : error = security_inode_getxattr(dentry, name);
442 : if (error)
443 : return error;
444 :
445 0 : if (!strncmp(name, XATTR_SECURITY_PREFIX,
446 : XATTR_SECURITY_PREFIX_LEN)) {
447 0 : const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
448 0 : int ret = xattr_getsecurity(idmap, inode, suffix, value,
449 : size);
450 : /*
451 : * Only overwrite the return value if a security module
452 : * is actually active.
453 : */
454 0 : if (ret == -EOPNOTSUPP)
455 : goto nolsm;
456 0 : return ret;
457 : }
458 : nolsm:
459 0 : return __vfs_getxattr(dentry, inode, name, value, size);
460 : }
461 : EXPORT_SYMBOL_GPL(vfs_getxattr);
462 :
463 : ssize_t
464 0 : vfs_listxattr(struct dentry *dentry, char *list, size_t size)
465 : {
466 0 : struct inode *inode = d_inode(dentry);
467 : ssize_t error;
468 :
469 0 : error = security_inode_listxattr(dentry);
470 : if (error)
471 : return error;
472 0 : if (inode->i_op->listxattr && (inode->i_opflags & IOP_XATTR)) {
473 0 : error = inode->i_op->listxattr(dentry, list, size);
474 : } else {
475 : error = security_inode_listsecurity(inode, list, size);
476 : if (size && error > size)
477 : error = -ERANGE;
478 : }
479 : return error;
480 : }
481 : EXPORT_SYMBOL_GPL(vfs_listxattr);
482 :
483 : int
484 0 : __vfs_removexattr(struct mnt_idmap *idmap, struct dentry *dentry,
485 : const char *name)
486 : {
487 0 : struct inode *inode = d_inode(dentry);
488 : const struct xattr_handler *handler;
489 :
490 0 : if (is_posix_acl_xattr(name))
491 : return -EOPNOTSUPP;
492 :
493 0 : handler = xattr_resolve_name(inode, &name);
494 0 : if (IS_ERR(handler))
495 0 : return PTR_ERR(handler);
496 0 : if (!handler->set)
497 : return -EOPNOTSUPP;
498 0 : return handler->set(handler, idmap, dentry, inode, name, NULL, 0,
499 : XATTR_REPLACE);
500 : }
501 : EXPORT_SYMBOL(__vfs_removexattr);
502 :
503 : /**
504 : * __vfs_removexattr_locked - set an extended attribute while holding the inode
505 : * lock
506 : *
507 : * @idmap: idmap of the mount of the target inode
508 : * @dentry: object to perform setxattr on
509 : * @name: name of xattr to remove
510 : * @delegated_inode: on return, will contain an inode pointer that
511 : * a delegation was broken on, NULL if none.
512 : */
513 : int
514 0 : __vfs_removexattr_locked(struct mnt_idmap *idmap,
515 : struct dentry *dentry, const char *name,
516 : struct inode **delegated_inode)
517 : {
518 0 : struct inode *inode = dentry->d_inode;
519 : int error;
520 :
521 0 : error = xattr_permission(idmap, inode, name, MAY_WRITE);
522 0 : if (error)
523 : return error;
524 :
525 0 : error = security_inode_removexattr(idmap, dentry, name);
526 0 : if (error)
527 : goto out;
528 :
529 0 : error = try_break_deleg(inode, delegated_inode);
530 0 : if (error)
531 : goto out;
532 :
533 0 : error = __vfs_removexattr(idmap, dentry, name);
534 :
535 0 : if (!error) {
536 : fsnotify_xattr(dentry);
537 : evm_inode_post_removexattr(dentry, name);
538 : }
539 :
540 : out:
541 : return error;
542 : }
543 : EXPORT_SYMBOL_GPL(__vfs_removexattr_locked);
544 :
545 : int
546 0 : vfs_removexattr(struct mnt_idmap *idmap, struct dentry *dentry,
547 : const char *name)
548 : {
549 0 : struct inode *inode = dentry->d_inode;
550 0 : struct inode *delegated_inode = NULL;
551 : int error;
552 :
553 : retry_deleg:
554 0 : inode_lock(inode);
555 0 : error = __vfs_removexattr_locked(idmap, dentry,
556 : name, &delegated_inode);
557 0 : inode_unlock(inode);
558 :
559 0 : if (delegated_inode) {
560 0 : error = break_deleg_wait(&delegated_inode);
561 0 : if (!error)
562 : goto retry_deleg;
563 : }
564 :
565 0 : return error;
566 : }
567 : EXPORT_SYMBOL_GPL(vfs_removexattr);
568 :
569 : /*
570 : * Extended attribute SET operations
571 : */
572 :
573 0 : int setxattr_copy(const char __user *name, struct xattr_ctx *ctx)
574 : {
575 : int error;
576 :
577 0 : if (ctx->flags & ~(XATTR_CREATE|XATTR_REPLACE))
578 : return -EINVAL;
579 :
580 0 : error = strncpy_from_user(ctx->kname->name, name,
581 : sizeof(ctx->kname->name));
582 0 : if (error == 0 || error == sizeof(ctx->kname->name))
583 : return -ERANGE;
584 0 : if (error < 0)
585 : return error;
586 :
587 0 : error = 0;
588 0 : if (ctx->size) {
589 0 : if (ctx->size > XATTR_SIZE_MAX)
590 : return -E2BIG;
591 :
592 0 : ctx->kvalue = vmemdup_user(ctx->cvalue, ctx->size);
593 0 : if (IS_ERR(ctx->kvalue)) {
594 0 : error = PTR_ERR(ctx->kvalue);
595 0 : ctx->kvalue = NULL;
596 : }
597 : }
598 :
599 : return error;
600 : }
601 :
602 0 : int do_setxattr(struct mnt_idmap *idmap, struct dentry *dentry,
603 : struct xattr_ctx *ctx)
604 : {
605 0 : if (is_posix_acl_xattr(ctx->kname->name))
606 : return do_set_acl(idmap, dentry, ctx->kname->name,
607 : ctx->kvalue, ctx->size);
608 :
609 0 : return vfs_setxattr(idmap, dentry, ctx->kname->name,
610 0 : ctx->kvalue, ctx->size, ctx->flags);
611 : }
612 :
613 : static long
614 0 : setxattr(struct mnt_idmap *idmap, struct dentry *d,
615 : const char __user *name, const void __user *value, size_t size,
616 : int flags)
617 : {
618 : struct xattr_name kname;
619 0 : struct xattr_ctx ctx = {
620 : .cvalue = value,
621 : .kvalue = NULL,
622 : .size = size,
623 : .kname = &kname,
624 : .flags = flags,
625 : };
626 : int error;
627 :
628 0 : error = setxattr_copy(name, &ctx);
629 0 : if (error)
630 0 : return error;
631 :
632 0 : error = do_setxattr(idmap, d, &ctx);
633 :
634 0 : kvfree(ctx.kvalue);
635 0 : return error;
636 : }
637 :
638 0 : static int path_setxattr(const char __user *pathname,
639 : const char __user *name, const void __user *value,
640 : size_t size, int flags, unsigned int lookup_flags)
641 : {
642 : struct path path;
643 : int error;
644 :
645 : retry:
646 0 : error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
647 0 : if (error)
648 : return error;
649 0 : error = mnt_want_write(path.mnt);
650 0 : if (!error) {
651 0 : error = setxattr(mnt_idmap(path.mnt), path.dentry, name,
652 : value, size, flags);
653 0 : mnt_drop_write(path.mnt);
654 : }
655 0 : path_put(&path);
656 0 : if (retry_estale(error, lookup_flags)) {
657 0 : lookup_flags |= LOOKUP_REVAL;
658 0 : goto retry;
659 : }
660 : return error;
661 : }
662 :
663 0 : SYSCALL_DEFINE5(setxattr, const char __user *, pathname,
664 : const char __user *, name, const void __user *, value,
665 : size_t, size, int, flags)
666 : {
667 0 : return path_setxattr(pathname, name, value, size, flags, LOOKUP_FOLLOW);
668 : }
669 :
670 0 : SYSCALL_DEFINE5(lsetxattr, const char __user *, pathname,
671 : const char __user *, name, const void __user *, value,
672 : size_t, size, int, flags)
673 : {
674 0 : return path_setxattr(pathname, name, value, size, flags, 0);
675 : }
676 :
677 0 : SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
678 : const void __user *,value, size_t, size, int, flags)
679 : {
680 0 : struct fd f = fdget(fd);
681 0 : int error = -EBADF;
682 :
683 0 : if (!f.file)
684 : return error;
685 0 : audit_file(f.file);
686 0 : error = mnt_want_write_file(f.file);
687 0 : if (!error) {
688 0 : error = setxattr(file_mnt_idmap(f.file),
689 : f.file->f_path.dentry, name,
690 : value, size, flags);
691 0 : mnt_drop_write_file(f.file);
692 : }
693 0 : fdput(f);
694 0 : return error;
695 : }
696 :
697 : /*
698 : * Extended attribute GET operations
699 : */
700 : ssize_t
701 0 : do_getxattr(struct mnt_idmap *idmap, struct dentry *d,
702 : struct xattr_ctx *ctx)
703 : {
704 : ssize_t error;
705 0 : char *kname = ctx->kname->name;
706 :
707 0 : if (ctx->size) {
708 0 : if (ctx->size > XATTR_SIZE_MAX)
709 0 : ctx->size = XATTR_SIZE_MAX;
710 0 : ctx->kvalue = kvzalloc(ctx->size, GFP_KERNEL);
711 0 : if (!ctx->kvalue)
712 : return -ENOMEM;
713 : }
714 :
715 0 : if (is_posix_acl_xattr(ctx->kname->name))
716 : error = do_get_acl(idmap, d, kname, ctx->kvalue, ctx->size);
717 : else
718 0 : error = vfs_getxattr(idmap, d, kname, ctx->kvalue, ctx->size);
719 0 : if (error > 0) {
720 0 : if (ctx->size && copy_to_user(ctx->value, ctx->kvalue, error))
721 0 : error = -EFAULT;
722 0 : } else if (error == -ERANGE && ctx->size >= XATTR_SIZE_MAX) {
723 : /* The file system tried to returned a value bigger
724 : than XATTR_SIZE_MAX bytes. Not possible. */
725 0 : error = -E2BIG;
726 : }
727 :
728 : return error;
729 : }
730 :
731 : static ssize_t
732 0 : getxattr(struct mnt_idmap *idmap, struct dentry *d,
733 : const char __user *name, void __user *value, size_t size)
734 : {
735 : ssize_t error;
736 : struct xattr_name kname;
737 0 : struct xattr_ctx ctx = {
738 : .value = value,
739 : .kvalue = NULL,
740 : .size = size,
741 : .kname = &kname,
742 : .flags = 0,
743 : };
744 :
745 0 : error = strncpy_from_user(kname.name, name, sizeof(kname.name));
746 0 : if (error == 0 || error == sizeof(kname.name))
747 0 : error = -ERANGE;
748 0 : if (error < 0)
749 : return error;
750 :
751 0 : error = do_getxattr(idmap, d, &ctx);
752 :
753 0 : kvfree(ctx.kvalue);
754 0 : return error;
755 : }
756 :
757 0 : static ssize_t path_getxattr(const char __user *pathname,
758 : const char __user *name, void __user *value,
759 : size_t size, unsigned int lookup_flags)
760 : {
761 : struct path path;
762 : ssize_t error;
763 : retry:
764 0 : error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
765 0 : if (error)
766 : return error;
767 0 : error = getxattr(mnt_idmap(path.mnt), path.dentry, name, value, size);
768 0 : path_put(&path);
769 0 : if (retry_estale(error, lookup_flags)) {
770 0 : lookup_flags |= LOOKUP_REVAL;
771 0 : goto retry;
772 : }
773 : return error;
774 : }
775 :
776 0 : SYSCALL_DEFINE4(getxattr, const char __user *, pathname,
777 : const char __user *, name, void __user *, value, size_t, size)
778 : {
779 0 : return path_getxattr(pathname, name, value, size, LOOKUP_FOLLOW);
780 : }
781 :
782 0 : SYSCALL_DEFINE4(lgetxattr, const char __user *, pathname,
783 : const char __user *, name, void __user *, value, size_t, size)
784 : {
785 0 : return path_getxattr(pathname, name, value, size, 0);
786 : }
787 :
788 0 : SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name,
789 : void __user *, value, size_t, size)
790 : {
791 0 : struct fd f = fdget(fd);
792 0 : ssize_t error = -EBADF;
793 :
794 0 : if (!f.file)
795 : return error;
796 0 : audit_file(f.file);
797 0 : error = getxattr(file_mnt_idmap(f.file), f.file->f_path.dentry,
798 : name, value, size);
799 0 : fdput(f);
800 : return error;
801 : }
802 :
803 : /*
804 : * Extended attribute LIST operations
805 : */
806 : static ssize_t
807 0 : listxattr(struct dentry *d, char __user *list, size_t size)
808 : {
809 : ssize_t error;
810 0 : char *klist = NULL;
811 :
812 0 : if (size) {
813 0 : if (size > XATTR_LIST_MAX)
814 0 : size = XATTR_LIST_MAX;
815 0 : klist = kvmalloc(size, GFP_KERNEL);
816 0 : if (!klist)
817 : return -ENOMEM;
818 : }
819 :
820 0 : error = vfs_listxattr(d, klist, size);
821 0 : if (error > 0) {
822 0 : if (size && copy_to_user(list, klist, error))
823 0 : error = -EFAULT;
824 0 : } else if (error == -ERANGE && size >= XATTR_LIST_MAX) {
825 : /* The file system tried to returned a list bigger
826 : than XATTR_LIST_MAX bytes. Not possible. */
827 0 : error = -E2BIG;
828 : }
829 :
830 0 : kvfree(klist);
831 :
832 0 : return error;
833 : }
834 :
835 0 : static ssize_t path_listxattr(const char __user *pathname, char __user *list,
836 : size_t size, unsigned int lookup_flags)
837 : {
838 : struct path path;
839 : ssize_t error;
840 : retry:
841 0 : error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
842 0 : if (error)
843 : return error;
844 0 : error = listxattr(path.dentry, list, size);
845 0 : path_put(&path);
846 0 : if (retry_estale(error, lookup_flags)) {
847 0 : lookup_flags |= LOOKUP_REVAL;
848 0 : goto retry;
849 : }
850 : return error;
851 : }
852 :
853 0 : SYSCALL_DEFINE3(listxattr, const char __user *, pathname, char __user *, list,
854 : size_t, size)
855 : {
856 0 : return path_listxattr(pathname, list, size, LOOKUP_FOLLOW);
857 : }
858 :
859 0 : SYSCALL_DEFINE3(llistxattr, const char __user *, pathname, char __user *, list,
860 : size_t, size)
861 : {
862 0 : return path_listxattr(pathname, list, size, 0);
863 : }
864 :
865 0 : SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size)
866 : {
867 0 : struct fd f = fdget(fd);
868 0 : ssize_t error = -EBADF;
869 :
870 0 : if (!f.file)
871 : return error;
872 0 : audit_file(f.file);
873 0 : error = listxattr(f.file->f_path.dentry, list, size);
874 0 : fdput(f);
875 : return error;
876 : }
877 :
878 : /*
879 : * Extended attribute REMOVE operations
880 : */
881 : static long
882 0 : removexattr(struct mnt_idmap *idmap, struct dentry *d,
883 : const char __user *name)
884 : {
885 : int error;
886 : char kname[XATTR_NAME_MAX + 1];
887 :
888 0 : error = strncpy_from_user(kname, name, sizeof(kname));
889 0 : if (error == 0 || error == sizeof(kname))
890 0 : error = -ERANGE;
891 0 : if (error < 0)
892 0 : return error;
893 :
894 0 : if (is_posix_acl_xattr(kname))
895 : return vfs_remove_acl(idmap, d, kname);
896 :
897 0 : return vfs_removexattr(idmap, d, kname);
898 : }
899 :
900 0 : static int path_removexattr(const char __user *pathname,
901 : const char __user *name, unsigned int lookup_flags)
902 : {
903 : struct path path;
904 : int error;
905 : retry:
906 0 : error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
907 0 : if (error)
908 : return error;
909 0 : error = mnt_want_write(path.mnt);
910 0 : if (!error) {
911 0 : error = removexattr(mnt_idmap(path.mnt), path.dentry, name);
912 0 : mnt_drop_write(path.mnt);
913 : }
914 0 : path_put(&path);
915 0 : if (retry_estale(error, lookup_flags)) {
916 0 : lookup_flags |= LOOKUP_REVAL;
917 0 : goto retry;
918 : }
919 : return error;
920 : }
921 :
922 0 : SYSCALL_DEFINE2(removexattr, const char __user *, pathname,
923 : const char __user *, name)
924 : {
925 0 : return path_removexattr(pathname, name, LOOKUP_FOLLOW);
926 : }
927 :
928 0 : SYSCALL_DEFINE2(lremovexattr, const char __user *, pathname,
929 : const char __user *, name)
930 : {
931 0 : return path_removexattr(pathname, name, 0);
932 : }
933 :
934 0 : SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)
935 : {
936 0 : struct fd f = fdget(fd);
937 0 : int error = -EBADF;
938 :
939 0 : if (!f.file)
940 : return error;
941 0 : audit_file(f.file);
942 0 : error = mnt_want_write_file(f.file);
943 0 : if (!error) {
944 0 : error = removexattr(file_mnt_idmap(f.file),
945 : f.file->f_path.dentry, name);
946 0 : mnt_drop_write_file(f.file);
947 : }
948 0 : fdput(f);
949 0 : return error;
950 : }
951 :
952 : /*
953 : * Combine the results of the list() operation from every xattr_handler in the
954 : * list.
955 : */
956 : ssize_t
957 0 : generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
958 : {
959 0 : const struct xattr_handler *handler, **handlers = dentry->d_sb->s_xattr;
960 0 : unsigned int size = 0;
961 :
962 0 : if (!buffer) {
963 0 : for_each_xattr_handler(handlers, handler) {
964 0 : if (!handler->name ||
965 0 : (handler->list && !handler->list(dentry)))
966 0 : continue;
967 0 : size += strlen(handler->name) + 1;
968 : }
969 : } else {
970 0 : char *buf = buffer;
971 : size_t len;
972 :
973 0 : for_each_xattr_handler(handlers, handler) {
974 0 : if (!handler->name ||
975 0 : (handler->list && !handler->list(dentry)))
976 0 : continue;
977 0 : len = strlen(handler->name);
978 0 : if (len + 1 > buffer_size)
979 : return -ERANGE;
980 0 : memcpy(buf, handler->name, len + 1);
981 0 : buf += len + 1;
982 0 : buffer_size -= len + 1;
983 : }
984 0 : size = buf - buffer;
985 : }
986 0 : return size;
987 : }
988 : EXPORT_SYMBOL(generic_listxattr);
989 :
990 : /**
991 : * xattr_full_name - Compute full attribute name from suffix
992 : *
993 : * @handler: handler of the xattr_handler operation
994 : * @name: name passed to the xattr_handler operation
995 : *
996 : * The get and set xattr handler operations are called with the remainder of
997 : * the attribute name after skipping the handler's prefix: for example, "foo"
998 : * is passed to the get operation of a handler with prefix "user." to get
999 : * attribute "user.foo". The full name is still "there" in the name though.
1000 : *
1001 : * Note: the list xattr handler operation when called from the vfs is passed a
1002 : * NULL name; some file systems use this operation internally, with varying
1003 : * semantics.
1004 : */
1005 0 : const char *xattr_full_name(const struct xattr_handler *handler,
1006 : const char *name)
1007 : {
1008 0 : size_t prefix_len = strlen(xattr_prefix(handler));
1009 :
1010 0 : return name - prefix_len;
1011 : }
1012 : EXPORT_SYMBOL(xattr_full_name);
1013 :
1014 : /**
1015 : * free_simple_xattr - free an xattr object
1016 : * @xattr: the xattr object
1017 : *
1018 : * Free the xattr object. Can handle @xattr being NULL.
1019 : */
1020 0 : static inline void free_simple_xattr(struct simple_xattr *xattr)
1021 : {
1022 0 : if (xattr)
1023 0 : kfree(xattr->name);
1024 0 : kvfree(xattr);
1025 0 : }
1026 :
1027 : /**
1028 : * simple_xattr_alloc - allocate new xattr object
1029 : * @value: value of the xattr object
1030 : * @size: size of @value
1031 : *
1032 : * Allocate a new xattr object and initialize respective members. The caller is
1033 : * responsible for handling the name of the xattr.
1034 : *
1035 : * Return: On success a new xattr object is returned. On failure NULL is
1036 : * returned.
1037 : */
1038 0 : struct simple_xattr *simple_xattr_alloc(const void *value, size_t size)
1039 : {
1040 : struct simple_xattr *new_xattr;
1041 : size_t len;
1042 :
1043 : /* wrap around? */
1044 0 : len = sizeof(*new_xattr) + size;
1045 0 : if (len < sizeof(*new_xattr))
1046 : return NULL;
1047 :
1048 0 : new_xattr = kvmalloc(len, GFP_KERNEL);
1049 0 : if (!new_xattr)
1050 : return NULL;
1051 :
1052 0 : new_xattr->size = size;
1053 0 : memcpy(new_xattr->value, value, size);
1054 0 : return new_xattr;
1055 : }
1056 :
1057 : /**
1058 : * rbtree_simple_xattr_cmp - compare xattr name with current rbtree xattr entry
1059 : * @key: xattr name
1060 : * @node: current node
1061 : *
1062 : * Compare the xattr name with the xattr name attached to @node in the rbtree.
1063 : *
1064 : * Return: Negative value if continuing left, positive if continuing right, 0
1065 : * if the xattr attached to @node matches @key.
1066 : */
1067 : static int rbtree_simple_xattr_cmp(const void *key, const struct rb_node *node)
1068 : {
1069 0 : const char *xattr_name = key;
1070 : const struct simple_xattr *xattr;
1071 :
1072 0 : xattr = rb_entry(node, struct simple_xattr, rb_node);
1073 0 : return strcmp(xattr->name, xattr_name);
1074 : }
1075 :
1076 : /**
1077 : * rbtree_simple_xattr_node_cmp - compare two xattr rbtree nodes
1078 : * @new_node: new node
1079 : * @node: current node
1080 : *
1081 : * Compare the xattr attached to @new_node with the xattr attached to @node.
1082 : *
1083 : * Return: Negative value if continuing left, positive if continuing right, 0
1084 : * if the xattr attached to @new_node matches the xattr attached to @node.
1085 : */
1086 : static int rbtree_simple_xattr_node_cmp(struct rb_node *new_node,
1087 : const struct rb_node *node)
1088 : {
1089 : struct simple_xattr *xattr;
1090 0 : xattr = rb_entry(new_node, struct simple_xattr, rb_node);
1091 0 : return rbtree_simple_xattr_cmp(xattr->name, node);
1092 : }
1093 :
1094 : /**
1095 : * simple_xattr_get - get an xattr object
1096 : * @xattrs: the header of the xattr object
1097 : * @name: the name of the xattr to retrieve
1098 : * @buffer: the buffer to store the value into
1099 : * @size: the size of @buffer
1100 : *
1101 : * Try to find and retrieve the xattr object associated with @name.
1102 : * If @buffer is provided store the value of @xattr in @buffer
1103 : * otherwise just return the length. The size of @buffer is limited
1104 : * to XATTR_SIZE_MAX which currently is 65536.
1105 : *
1106 : * Return: On success the length of the xattr value is returned. On error a
1107 : * negative error code is returned.
1108 : */
1109 0 : int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
1110 : void *buffer, size_t size)
1111 : {
1112 0 : struct simple_xattr *xattr = NULL;
1113 : struct rb_node *rbp;
1114 0 : int ret = -ENODATA;
1115 :
1116 0 : read_lock(&xattrs->lock);
1117 0 : rbp = rb_find(name, &xattrs->rb_root, rbtree_simple_xattr_cmp);
1118 0 : if (rbp) {
1119 0 : xattr = rb_entry(rbp, struct simple_xattr, rb_node);
1120 0 : ret = xattr->size;
1121 0 : if (buffer) {
1122 0 : if (size < xattr->size)
1123 : ret = -ERANGE;
1124 : else
1125 0 : memcpy(buffer, xattr->value, xattr->size);
1126 : }
1127 : }
1128 0 : read_unlock(&xattrs->lock);
1129 0 : return ret;
1130 : }
1131 :
1132 : /**
1133 : * simple_xattr_set - set an xattr object
1134 : * @xattrs: the header of the xattr object
1135 : * @name: the name of the xattr to retrieve
1136 : * @value: the value to store along the xattr
1137 : * @size: the size of @value
1138 : * @flags: the flags determining how to set the xattr
1139 : * @removed_size: the size of the removed xattr
1140 : *
1141 : * Set a new xattr object.
1142 : * If @value is passed a new xattr object will be allocated. If XATTR_REPLACE
1143 : * is specified in @flags a matching xattr object for @name must already exist.
1144 : * If it does it will be replaced with the new xattr object. If it doesn't we
1145 : * fail. If XATTR_CREATE is specified and a matching xattr does already exist
1146 : * we fail. If it doesn't we create a new xattr. If @flags is zero we simply
1147 : * insert the new xattr replacing any existing one.
1148 : *
1149 : * If @value is empty and a matching xattr object is found we delete it if
1150 : * XATTR_REPLACE is specified in @flags or @flags is zero.
1151 : *
1152 : * If @value is empty and no matching xattr object for @name is found we do
1153 : * nothing if XATTR_CREATE is specified in @flags or @flags is zero. For
1154 : * XATTR_REPLACE we fail as mentioned above.
1155 : *
1156 : * Return: On success zero and on error a negative error code is returned.
1157 : */
1158 0 : int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
1159 : const void *value, size_t size, int flags,
1160 : ssize_t *removed_size)
1161 : {
1162 0 : struct simple_xattr *xattr = NULL, *new_xattr = NULL;
1163 0 : struct rb_node *parent = NULL, **rbp;
1164 0 : int err = 0, ret;
1165 :
1166 0 : if (removed_size)
1167 0 : *removed_size = -1;
1168 :
1169 : /* value == NULL means remove */
1170 0 : if (value) {
1171 0 : new_xattr = simple_xattr_alloc(value, size);
1172 0 : if (!new_xattr)
1173 : return -ENOMEM;
1174 :
1175 0 : new_xattr->name = kstrdup(name, GFP_KERNEL);
1176 0 : if (!new_xattr->name) {
1177 0 : free_simple_xattr(new_xattr);
1178 0 : return -ENOMEM;
1179 : }
1180 : }
1181 :
1182 0 : write_lock(&xattrs->lock);
1183 0 : rbp = &xattrs->rb_root.rb_node;
1184 0 : while (*rbp) {
1185 0 : parent = *rbp;
1186 0 : ret = rbtree_simple_xattr_cmp(name, *rbp);
1187 0 : if (ret < 0)
1188 0 : rbp = &(*rbp)->rb_left;
1189 0 : else if (ret > 0)
1190 0 : rbp = &(*rbp)->rb_right;
1191 : else
1192 0 : xattr = rb_entry(*rbp, struct simple_xattr, rb_node);
1193 0 : if (xattr)
1194 : break;
1195 : }
1196 :
1197 0 : if (xattr) {
1198 : /* Fail if XATTR_CREATE is requested and the xattr exists. */
1199 0 : if (flags & XATTR_CREATE) {
1200 : err = -EEXIST;
1201 : goto out_unlock;
1202 : }
1203 :
1204 0 : if (new_xattr)
1205 0 : rb_replace_node(&xattr->rb_node, &new_xattr->rb_node,
1206 : &xattrs->rb_root);
1207 : else
1208 0 : rb_erase(&xattr->rb_node, &xattrs->rb_root);
1209 0 : if (!err && removed_size)
1210 0 : *removed_size = xattr->size;
1211 : } else {
1212 : /* Fail if XATTR_REPLACE is requested but no xattr is found. */
1213 0 : if (flags & XATTR_REPLACE) {
1214 : err = -ENODATA;
1215 : goto out_unlock;
1216 : }
1217 :
1218 : /*
1219 : * If XATTR_CREATE or no flags are specified together with a
1220 : * new value simply insert it.
1221 : */
1222 0 : if (new_xattr) {
1223 0 : rb_link_node(&new_xattr->rb_node, parent, rbp);
1224 0 : rb_insert_color(&new_xattr->rb_node, &xattrs->rb_root);
1225 : }
1226 :
1227 : /*
1228 : * If XATTR_CREATE or no flags are specified and neither an
1229 : * old or new xattr exist then we don't need to do anything.
1230 : */
1231 : }
1232 :
1233 : out_unlock:
1234 0 : write_unlock(&xattrs->lock);
1235 0 : if (err)
1236 0 : free_simple_xattr(new_xattr);
1237 : else
1238 0 : free_simple_xattr(xattr);
1239 : return err;
1240 :
1241 : }
1242 :
1243 : static bool xattr_is_trusted(const char *name)
1244 : {
1245 0 : return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
1246 : }
1247 :
1248 0 : static int xattr_list_one(char **buffer, ssize_t *remaining_size,
1249 : const char *name)
1250 : {
1251 0 : size_t len = strlen(name) + 1;
1252 0 : if (*buffer) {
1253 0 : if (*remaining_size < len)
1254 : return -ERANGE;
1255 0 : memcpy(*buffer, name, len);
1256 0 : *buffer += len;
1257 : }
1258 0 : *remaining_size -= len;
1259 0 : return 0;
1260 : }
1261 :
1262 : /**
1263 : * simple_xattr_list - list all xattr objects
1264 : * @inode: inode from which to get the xattrs
1265 : * @xattrs: the header of the xattr object
1266 : * @buffer: the buffer to store all xattrs into
1267 : * @size: the size of @buffer
1268 : *
1269 : * List all xattrs associated with @inode. If @buffer is NULL we returned
1270 : * the required size of the buffer. If @buffer is provided we store the
1271 : * xattrs value into it provided it is big enough.
1272 : *
1273 : * Note, the number of xattr names that can be listed with listxattr(2) is
1274 : * limited to XATTR_LIST_MAX aka 65536 bytes. If a larger buffer is passed
1275 : * then vfs_listxattr() caps it to XATTR_LIST_MAX and if more xattr names
1276 : * are found it will return -E2BIG.
1277 : *
1278 : * Return: On success the required size or the size of the copied xattrs is
1279 : * returned. On error a negative error code is returned.
1280 : */
1281 0 : ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
1282 : char *buffer, size_t size)
1283 : {
1284 0 : bool trusted = ns_capable_noaudit(&init_user_ns, CAP_SYS_ADMIN);
1285 : struct simple_xattr *xattr;
1286 : struct rb_node *rbp;
1287 0 : ssize_t remaining_size = size;
1288 0 : int err = 0;
1289 :
1290 : #ifdef CONFIG_FS_POSIX_ACL
1291 : if (IS_POSIXACL(inode)) {
1292 : if (inode->i_acl) {
1293 : err = xattr_list_one(&buffer, &remaining_size,
1294 : XATTR_NAME_POSIX_ACL_ACCESS);
1295 : if (err)
1296 : return err;
1297 : }
1298 : if (inode->i_default_acl) {
1299 : err = xattr_list_one(&buffer, &remaining_size,
1300 : XATTR_NAME_POSIX_ACL_DEFAULT);
1301 : if (err)
1302 : return err;
1303 : }
1304 : }
1305 : #endif
1306 :
1307 0 : read_lock(&xattrs->lock);
1308 0 : for (rbp = rb_first(&xattrs->rb_root); rbp; rbp = rb_next(rbp)) {
1309 0 : xattr = rb_entry(rbp, struct simple_xattr, rb_node);
1310 :
1311 : /* skip "trusted." attributes for unprivileged callers */
1312 0 : if (!trusted && xattr_is_trusted(xattr->name))
1313 0 : continue;
1314 :
1315 0 : err = xattr_list_one(&buffer, &remaining_size, xattr->name);
1316 0 : if (err)
1317 : break;
1318 : }
1319 0 : read_unlock(&xattrs->lock);
1320 :
1321 0 : return err ? err : size - remaining_size;
1322 : }
1323 :
1324 : /**
1325 : * rbtree_simple_xattr_less - compare two xattr rbtree nodes
1326 : * @new_node: new node
1327 : * @node: current node
1328 : *
1329 : * Compare the xattr attached to @new_node with the xattr attached to @node.
1330 : * Note that this function technically tolerates duplicate entries.
1331 : *
1332 : * Return: True if insertion point in the rbtree is found.
1333 : */
1334 : static bool rbtree_simple_xattr_less(struct rb_node *new_node,
1335 : const struct rb_node *node)
1336 : {
1337 0 : return rbtree_simple_xattr_node_cmp(new_node, node) < 0;
1338 : }
1339 :
1340 : /**
1341 : * simple_xattr_add - add xattr objects
1342 : * @xattrs: the header of the xattr object
1343 : * @new_xattr: the xattr object to add
1344 : *
1345 : * Add an xattr object to @xattrs. This assumes no replacement or removal
1346 : * of matching xattrs is wanted. Should only be called during inode
1347 : * initialization when a few distinct initial xattrs are supposed to be set.
1348 : */
1349 0 : void simple_xattr_add(struct simple_xattrs *xattrs,
1350 : struct simple_xattr *new_xattr)
1351 : {
1352 0 : write_lock(&xattrs->lock);
1353 0 : rb_add(&new_xattr->rb_node, &xattrs->rb_root, rbtree_simple_xattr_less);
1354 0 : write_unlock(&xattrs->lock);
1355 0 : }
1356 :
1357 : /**
1358 : * simple_xattrs_init - initialize new xattr header
1359 : * @xattrs: header to initialize
1360 : *
1361 : * Initialize relevant fields of a an xattr header.
1362 : */
1363 1 : void simple_xattrs_init(struct simple_xattrs *xattrs)
1364 : {
1365 1 : xattrs->rb_root = RB_ROOT;
1366 : rwlock_init(&xattrs->lock);
1367 1 : }
1368 :
1369 : /**
1370 : * simple_xattrs_free - free xattrs
1371 : * @xattrs: xattr header whose xattrs to destroy
1372 : *
1373 : * Destroy all xattrs in @xattr. When this is called no one can hold a
1374 : * reference to any of the xattrs anymore.
1375 : */
1376 0 : void simple_xattrs_free(struct simple_xattrs *xattrs)
1377 : {
1378 : struct rb_node *rbp;
1379 :
1380 0 : rbp = rb_first(&xattrs->rb_root);
1381 0 : while (rbp) {
1382 : struct simple_xattr *xattr;
1383 : struct rb_node *rbp_next;
1384 :
1385 0 : rbp_next = rb_next(rbp);
1386 0 : xattr = rb_entry(rbp, struct simple_xattr, rb_node);
1387 0 : rb_erase(&xattr->rb_node, &xattrs->rb_root);
1388 0 : free_simple_xattr(xattr);
1389 0 : rbp = rbp_next;
1390 : }
1391 0 : }
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