xref: /openbmc/linux/fs/ubifs/xattr.c (revision aa5b395b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * This file is part of UBIFS.
4  *
5  * Copyright (C) 2006-2008 Nokia Corporation.
6  *
7  * Authors: Artem Bityutskiy (Битюцкий Артём)
8  *          Adrian Hunter
9  */
10 
11 /*
12  * This file implements UBIFS extended attributes support.
13  *
14  * Extended attributes are implemented as regular inodes with attached data,
15  * which limits extended attribute size to UBIFS block size (4KiB). Names of
16  * extended attributes are described by extended attribute entries (xentries),
17  * which are almost identical to directory entries, but have different key type.
18  *
19  * In other words, the situation with extended attributes is very similar to
20  * directories. Indeed, any inode (but of course not xattr inodes) may have a
21  * number of associated xentries, just like directory inodes have associated
22  * directory entries. Extended attribute entries store the name of the extended
23  * attribute, the host inode number, and the extended attribute inode number.
24  * Similarly, direntries store the name, the parent and the target inode
25  * numbers. Thus, most of the common UBIFS mechanisms may be re-used for
26  * extended attributes.
27  *
28  * The number of extended attributes is not limited, but there is Linux
29  * limitation on the maximum possible size of the list of all extended
30  * attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure
31  * the sum of all extended attribute names of the inode does not exceed that
32  * limit.
33  *
34  * Extended attributes are synchronous, which means they are written to the
35  * flash media synchronously and there is no write-back for extended attribute
36  * inodes. The extended attribute values are not stored in compressed form on
37  * the media.
38  *
39  * Since extended attributes are represented by regular inodes, they are cached
40  * in the VFS inode cache. The xentries are cached in the LNC cache (see
41  * tnc.c).
42  *
43  * ACL support is not implemented.
44  */
45 
46 #include "ubifs.h"
47 #include <linux/fs.h>
48 #include <linux/slab.h>
49 #include <linux/xattr.h>
50 
51 /*
52  * Extended attribute type constants.
53  *
54  * USER_XATTR: user extended attribute ("user.*")
55  * TRUSTED_XATTR: trusted extended attribute ("trusted.*)
56  * SECURITY_XATTR: security extended attribute ("security.*")
57  */
58 enum {
59 	USER_XATTR,
60 	TRUSTED_XATTR,
61 	SECURITY_XATTR,
62 };
63 
64 static const struct inode_operations empty_iops;
65 static const struct file_operations empty_fops;
66 
67 /**
68  * create_xattr - create an extended attribute.
69  * @c: UBIFS file-system description object
70  * @host: host inode
71  * @nm: extended attribute name
72  * @value: extended attribute value
73  * @size: size of extended attribute value
74  *
75  * This is a helper function which creates an extended attribute of name @nm
76  * and value @value for inode @host. The host inode is also updated on flash
77  * because the ctime and extended attribute accounting data changes. This
78  * function returns zero in case of success and a negative error code in case
79  * of failure.
80  */
81 static int create_xattr(struct ubifs_info *c, struct inode *host,
82 			const struct fscrypt_name *nm, const void *value, int size)
83 {
84 	int err, names_len;
85 	struct inode *inode;
86 	struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
87 	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
88 				.new_ino_d = ALIGN(size, 8), .dirtied_ino = 1,
89 				.dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
90 
91 	if (host_ui->xattr_cnt >= ubifs_xattr_max_cnt(c)) {
92 		ubifs_err(c, "inode %lu already has too many xattrs (%d), cannot create more",
93 			  host->i_ino, host_ui->xattr_cnt);
94 		return -ENOSPC;
95 	}
96 	/*
97 	 * Linux limits the maximum size of the extended attribute names list
98 	 * to %XATTR_LIST_MAX. This means we should not allow creating more
99 	 * extended attributes if the name list becomes larger. This limitation
100 	 * is artificial for UBIFS, though.
101 	 */
102 	names_len = host_ui->xattr_names + host_ui->xattr_cnt + fname_len(nm) + 1;
103 	if (names_len > XATTR_LIST_MAX) {
104 		ubifs_err(c, "cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d",
105 			  host->i_ino, names_len, XATTR_LIST_MAX);
106 		return -ENOSPC;
107 	}
108 
109 	err = ubifs_budget_space(c, &req);
110 	if (err)
111 		return err;
112 
113 	inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO);
114 	if (IS_ERR(inode)) {
115 		err = PTR_ERR(inode);
116 		goto out_budg;
117 	}
118 
119 	/* Re-define all operations to be "nothing" */
120 	inode->i_mapping->a_ops = &empty_aops;
121 	inode->i_op = &empty_iops;
122 	inode->i_fop = &empty_fops;
123 
124 	inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME;
125 	ui = ubifs_inode(inode);
126 	ui->xattr = 1;
127 	ui->flags |= UBIFS_XATTR_FL;
128 	ui->data = kmemdup(value, size, GFP_NOFS);
129 	if (!ui->data) {
130 		err = -ENOMEM;
131 		goto out_free;
132 	}
133 	inode->i_size = ui->ui_size = size;
134 	ui->data_len = size;
135 
136 	mutex_lock(&host_ui->ui_mutex);
137 	host->i_ctime = current_time(host);
138 	host_ui->xattr_cnt += 1;
139 	host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
140 	host_ui->xattr_size += CALC_XATTR_BYTES(size);
141 	host_ui->xattr_names += fname_len(nm);
142 
143 	/*
144 	 * We handle UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT here because we
145 	 * have to set the UBIFS_CRYPT_FL flag on the host inode.
146 	 * To avoid multiple updates of the same inode in the same operation,
147 	 * let's do it here.
148 	 */
149 	if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
150 		host_ui->flags |= UBIFS_CRYPT_FL;
151 
152 	err = ubifs_jnl_update(c, host, nm, inode, 0, 1);
153 	if (err)
154 		goto out_cancel;
155 	ubifs_set_inode_flags(host);
156 	mutex_unlock(&host_ui->ui_mutex);
157 
158 	ubifs_release_budget(c, &req);
159 	insert_inode_hash(inode);
160 	iput(inode);
161 	return 0;
162 
163 out_cancel:
164 	host_ui->xattr_cnt -= 1;
165 	host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
166 	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
167 	host_ui->xattr_names -= fname_len(nm);
168 	host_ui->flags &= ~UBIFS_CRYPT_FL;
169 	mutex_unlock(&host_ui->ui_mutex);
170 out_free:
171 	make_bad_inode(inode);
172 	iput(inode);
173 out_budg:
174 	ubifs_release_budget(c, &req);
175 	return err;
176 }
177 
178 /**
179  * change_xattr - change an extended attribute.
180  * @c: UBIFS file-system description object
181  * @host: host inode
182  * @inode: extended attribute inode
183  * @value: extended attribute value
184  * @size: size of extended attribute value
185  *
186  * This helper function changes the value of extended attribute @inode with new
187  * data from @value. Returns zero in case of success and a negative error code
188  * in case of failure.
189  */
190 static int change_xattr(struct ubifs_info *c, struct inode *host,
191 			struct inode *inode, const void *value, int size)
192 {
193 	int err;
194 	struct ubifs_inode *host_ui = ubifs_inode(host);
195 	struct ubifs_inode *ui = ubifs_inode(inode);
196 	void *buf = NULL;
197 	int old_size;
198 	struct ubifs_budget_req req = { .dirtied_ino = 2,
199 		.dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) };
200 
201 	ubifs_assert(c, ui->data_len == inode->i_size);
202 	err = ubifs_budget_space(c, &req);
203 	if (err)
204 		return err;
205 
206 	buf = kmemdup(value, size, GFP_NOFS);
207 	if (!buf) {
208 		err = -ENOMEM;
209 		goto out_free;
210 	}
211 	mutex_lock(&ui->ui_mutex);
212 	kfree(ui->data);
213 	ui->data = buf;
214 	inode->i_size = ui->ui_size = size;
215 	old_size = ui->data_len;
216 	ui->data_len = size;
217 	mutex_unlock(&ui->ui_mutex);
218 
219 	mutex_lock(&host_ui->ui_mutex);
220 	host->i_ctime = current_time(host);
221 	host_ui->xattr_size -= CALC_XATTR_BYTES(old_size);
222 	host_ui->xattr_size += CALC_XATTR_BYTES(size);
223 
224 	/*
225 	 * It is important to write the host inode after the xattr inode
226 	 * because if the host inode gets synchronized (via 'fsync()'), then
227 	 * the extended attribute inode gets synchronized, because it goes
228 	 * before the host inode in the write-buffer.
229 	 */
230 	err = ubifs_jnl_change_xattr(c, inode, host);
231 	if (err)
232 		goto out_cancel;
233 	mutex_unlock(&host_ui->ui_mutex);
234 
235 	ubifs_release_budget(c, &req);
236 	return 0;
237 
238 out_cancel:
239 	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
240 	host_ui->xattr_size += CALC_XATTR_BYTES(old_size);
241 	mutex_unlock(&host_ui->ui_mutex);
242 	make_bad_inode(inode);
243 out_free:
244 	ubifs_release_budget(c, &req);
245 	return err;
246 }
247 
248 static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
249 {
250 	struct inode *inode;
251 
252 	inode = ubifs_iget(c->vfs_sb, inum);
253 	if (IS_ERR(inode)) {
254 		ubifs_err(c, "dead extended attribute entry, error %d",
255 			  (int)PTR_ERR(inode));
256 		return inode;
257 	}
258 	if (ubifs_inode(inode)->xattr)
259 		return inode;
260 	ubifs_err(c, "corrupt extended attribute entry");
261 	iput(inode);
262 	return ERR_PTR(-EINVAL);
263 }
264 
265 int ubifs_xattr_set(struct inode *host, const char *name, const void *value,
266 		    size_t size, int flags, bool check_lock)
267 {
268 	struct inode *inode;
269 	struct ubifs_info *c = host->i_sb->s_fs_info;
270 	struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
271 	struct ubifs_dent_node *xent;
272 	union ubifs_key key;
273 	int err;
274 
275 	if (check_lock)
276 		ubifs_assert(c, inode_is_locked(host));
277 
278 	if (size > UBIFS_MAX_INO_DATA)
279 		return -ERANGE;
280 
281 	if (fname_len(&nm) > UBIFS_MAX_NLEN)
282 		return -ENAMETOOLONG;
283 
284 	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
285 	if (!xent)
286 		return -ENOMEM;
287 
288 	/*
289 	 * The extended attribute entries are stored in LNC, so multiple
290 	 * look-ups do not involve reading the flash.
291 	 */
292 	xent_key_init(c, &key, host->i_ino, &nm);
293 	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
294 	if (err) {
295 		if (err != -ENOENT)
296 			goto out_free;
297 
298 		if (flags & XATTR_REPLACE)
299 			/* We are asked not to create the xattr */
300 			err = -ENODATA;
301 		else
302 			err = create_xattr(c, host, &nm, value, size);
303 		goto out_free;
304 	}
305 
306 	if (flags & XATTR_CREATE) {
307 		/* We are asked not to replace the xattr */
308 		err = -EEXIST;
309 		goto out_free;
310 	}
311 
312 	inode = iget_xattr(c, le64_to_cpu(xent->inum));
313 	if (IS_ERR(inode)) {
314 		err = PTR_ERR(inode);
315 		goto out_free;
316 	}
317 
318 	err = change_xattr(c, host, inode, value, size);
319 	iput(inode);
320 
321 out_free:
322 	kfree(xent);
323 	return err;
324 }
325 
326 ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf,
327 			size_t size)
328 {
329 	struct inode *inode;
330 	struct ubifs_info *c = host->i_sb->s_fs_info;
331 	struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
332 	struct ubifs_inode *ui;
333 	struct ubifs_dent_node *xent;
334 	union ubifs_key key;
335 	int err;
336 
337 	if (fname_len(&nm) > UBIFS_MAX_NLEN)
338 		return -ENAMETOOLONG;
339 
340 	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
341 	if (!xent)
342 		return -ENOMEM;
343 
344 	xent_key_init(c, &key, host->i_ino, &nm);
345 	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
346 	if (err) {
347 		if (err == -ENOENT)
348 			err = -ENODATA;
349 		goto out_unlock;
350 	}
351 
352 	inode = iget_xattr(c, le64_to_cpu(xent->inum));
353 	if (IS_ERR(inode)) {
354 		err = PTR_ERR(inode);
355 		goto out_unlock;
356 	}
357 
358 	ui = ubifs_inode(inode);
359 	ubifs_assert(c, inode->i_size == ui->data_len);
360 	ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len);
361 
362 	mutex_lock(&ui->ui_mutex);
363 	if (buf) {
364 		/* If @buf is %NULL we are supposed to return the length */
365 		if (ui->data_len > size) {
366 			err = -ERANGE;
367 			goto out_iput;
368 		}
369 
370 		memcpy(buf, ui->data, ui->data_len);
371 	}
372 	err = ui->data_len;
373 
374 out_iput:
375 	mutex_unlock(&ui->ui_mutex);
376 	iput(inode);
377 out_unlock:
378 	kfree(xent);
379 	return err;
380 }
381 
382 static bool xattr_visible(const char *name)
383 {
384 	/* File encryption related xattrs are for internal use only */
385 	if (strcmp(name, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0)
386 		return false;
387 
388 	/* Show trusted namespace only for "power" users */
389 	if (strncmp(name, XATTR_TRUSTED_PREFIX,
390 		    XATTR_TRUSTED_PREFIX_LEN) == 0 && !capable(CAP_SYS_ADMIN))
391 		return false;
392 
393 	return true;
394 }
395 
396 ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
397 {
398 	union ubifs_key key;
399 	struct inode *host = d_inode(dentry);
400 	struct ubifs_info *c = host->i_sb->s_fs_info;
401 	struct ubifs_inode *host_ui = ubifs_inode(host);
402 	struct ubifs_dent_node *xent, *pxent = NULL;
403 	int err, len, written = 0;
404 	struct fscrypt_name nm = {0};
405 
406 	dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino,
407 		dentry, size);
408 
409 	len = host_ui->xattr_names + host_ui->xattr_cnt;
410 	if (!buffer)
411 		/*
412 		 * We should return the minimum buffer size which will fit a
413 		 * null-terminated list of all the extended attribute names.
414 		 */
415 		return len;
416 
417 	if (len > size)
418 		return -ERANGE;
419 
420 	lowest_xent_key(c, &key, host->i_ino);
421 	while (1) {
422 		xent = ubifs_tnc_next_ent(c, &key, &nm);
423 		if (IS_ERR(xent)) {
424 			err = PTR_ERR(xent);
425 			break;
426 		}
427 
428 		fname_name(&nm) = xent->name;
429 		fname_len(&nm) = le16_to_cpu(xent->nlen);
430 
431 		if (xattr_visible(xent->name)) {
432 			memcpy(buffer + written, fname_name(&nm), fname_len(&nm) + 1);
433 			written += fname_len(&nm) + 1;
434 		}
435 
436 		kfree(pxent);
437 		pxent = xent;
438 		key_read(c, &xent->key, &key);
439 	}
440 
441 	kfree(pxent);
442 	if (err != -ENOENT) {
443 		ubifs_err(c, "cannot find next direntry, error %d", err);
444 		return err;
445 	}
446 
447 	ubifs_assert(c, written <= size);
448 	return written;
449 }
450 
451 static int remove_xattr(struct ubifs_info *c, struct inode *host,
452 			struct inode *inode, const struct fscrypt_name *nm)
453 {
454 	int err;
455 	struct ubifs_inode *host_ui = ubifs_inode(host);
456 	struct ubifs_inode *ui = ubifs_inode(inode);
457 	struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1,
458 				.dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
459 
460 	ubifs_assert(c, ui->data_len == inode->i_size);
461 
462 	err = ubifs_budget_space(c, &req);
463 	if (err)
464 		return err;
465 
466 	mutex_lock(&host_ui->ui_mutex);
467 	host->i_ctime = current_time(host);
468 	host_ui->xattr_cnt -= 1;
469 	host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
470 	host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
471 	host_ui->xattr_names -= fname_len(nm);
472 
473 	err = ubifs_jnl_delete_xattr(c, host, inode, nm);
474 	if (err)
475 		goto out_cancel;
476 	mutex_unlock(&host_ui->ui_mutex);
477 
478 	ubifs_release_budget(c, &req);
479 	return 0;
480 
481 out_cancel:
482 	host_ui->xattr_cnt += 1;
483 	host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
484 	host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
485 	host_ui->xattr_names += fname_len(nm);
486 	mutex_unlock(&host_ui->ui_mutex);
487 	ubifs_release_budget(c, &req);
488 	make_bad_inode(inode);
489 	return err;
490 }
491 
492 int ubifs_purge_xattrs(struct inode *host)
493 {
494 	union ubifs_key key;
495 	struct ubifs_info *c = host->i_sb->s_fs_info;
496 	struct ubifs_dent_node *xent, *pxent = NULL;
497 	struct inode *xino;
498 	struct fscrypt_name nm = {0};
499 	int err;
500 
501 	if (ubifs_inode(host)->xattr_cnt < ubifs_xattr_max_cnt(c))
502 		return 0;
503 
504 	ubifs_warn(c, "inode %lu has too many xattrs, doing a non-atomic deletion",
505 		   host->i_ino);
506 
507 	lowest_xent_key(c, &key, host->i_ino);
508 	while (1) {
509 		xent = ubifs_tnc_next_ent(c, &key, &nm);
510 		if (IS_ERR(xent)) {
511 			err = PTR_ERR(xent);
512 			break;
513 		}
514 
515 		fname_name(&nm) = xent->name;
516 		fname_len(&nm) = le16_to_cpu(xent->nlen);
517 
518 		xino = ubifs_iget(c->vfs_sb, le64_to_cpu(xent->inum));
519 		if (IS_ERR(xino)) {
520 			err = PTR_ERR(xino);
521 			ubifs_err(c, "dead directory entry '%s', error %d",
522 				  xent->name, err);
523 			ubifs_ro_mode(c, err);
524 			kfree(pxent);
525 			return err;
526 		}
527 
528 		ubifs_assert(c, ubifs_inode(xino)->xattr);
529 
530 		clear_nlink(xino);
531 		err = remove_xattr(c, host, xino, &nm);
532 		if (err) {
533 			kfree(pxent);
534 			iput(xino);
535 			ubifs_err(c, "cannot remove xattr, error %d", err);
536 			return err;
537 		}
538 
539 		iput(xino);
540 
541 		kfree(pxent);
542 		pxent = xent;
543 		key_read(c, &xent->key, &key);
544 	}
545 
546 	kfree(pxent);
547 	if (err != -ENOENT) {
548 		ubifs_err(c, "cannot find next direntry, error %d", err);
549 		return err;
550 	}
551 
552 	return 0;
553 }
554 
555 /**
556  * ubifs_evict_xattr_inode - Evict an xattr inode.
557  * @c: UBIFS file-system description object
558  * @xattr_inum: xattr inode number
559  *
560  * When an inode that hosts xattrs is being removed we have to make sure
561  * that cached inodes of the xattrs also get removed from the inode cache
562  * otherwise we'd waste memory. This function looks up an inode from the
563  * inode cache and clears the link counter such that iput() will evict
564  * the inode.
565  */
566 void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum)
567 {
568 	struct inode *inode;
569 
570 	inode = ilookup(c->vfs_sb, xattr_inum);
571 	if (inode) {
572 		clear_nlink(inode);
573 		iput(inode);
574 	}
575 }
576 
577 static int ubifs_xattr_remove(struct inode *host, const char *name)
578 {
579 	struct inode *inode;
580 	struct ubifs_info *c = host->i_sb->s_fs_info;
581 	struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
582 	struct ubifs_dent_node *xent;
583 	union ubifs_key key;
584 	int err;
585 
586 	ubifs_assert(c, inode_is_locked(host));
587 
588 	if (fname_len(&nm) > UBIFS_MAX_NLEN)
589 		return -ENAMETOOLONG;
590 
591 	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
592 	if (!xent)
593 		return -ENOMEM;
594 
595 	xent_key_init(c, &key, host->i_ino, &nm);
596 	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
597 	if (err) {
598 		if (err == -ENOENT)
599 			err = -ENODATA;
600 		goto out_free;
601 	}
602 
603 	inode = iget_xattr(c, le64_to_cpu(xent->inum));
604 	if (IS_ERR(inode)) {
605 		err = PTR_ERR(inode);
606 		goto out_free;
607 	}
608 
609 	ubifs_assert(c, inode->i_nlink == 1);
610 	clear_nlink(inode);
611 	err = remove_xattr(c, host, inode, &nm);
612 	if (err)
613 		set_nlink(inode, 1);
614 
615 	/* If @i_nlink is 0, 'iput()' will delete the inode */
616 	iput(inode);
617 
618 out_free:
619 	kfree(xent);
620 	return err;
621 }
622 
623 #ifdef CONFIG_UBIFS_FS_SECURITY
624 static int init_xattrs(struct inode *inode, const struct xattr *xattr_array,
625 		      void *fs_info)
626 {
627 	const struct xattr *xattr;
628 	char *name;
629 	int err = 0;
630 
631 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
632 		name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
633 			       strlen(xattr->name) + 1, GFP_NOFS);
634 		if (!name) {
635 			err = -ENOMEM;
636 			break;
637 		}
638 		strcpy(name, XATTR_SECURITY_PREFIX);
639 		strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
640 		/*
641 		 * creating a new inode without holding the inode rwsem,
642 		 * no need to check whether inode is locked.
643 		 */
644 		err = ubifs_xattr_set(inode, name, xattr->value,
645 				      xattr->value_len, 0, false);
646 		kfree(name);
647 		if (err < 0)
648 			break;
649 	}
650 
651 	return err;
652 }
653 
654 int ubifs_init_security(struct inode *dentry, struct inode *inode,
655 			const struct qstr *qstr)
656 {
657 	int err;
658 
659 	err = security_inode_init_security(inode, dentry, qstr,
660 					   &init_xattrs, 0);
661 	if (err) {
662 		struct ubifs_info *c = dentry->i_sb->s_fs_info;
663 		ubifs_err(c, "cannot initialize security for inode %lu, error %d",
664 			  inode->i_ino, err);
665 	}
666 	return err;
667 }
668 #endif
669 
670 static int xattr_get(const struct xattr_handler *handler,
671 			   struct dentry *dentry, struct inode *inode,
672 			   const char *name, void *buffer, size_t size)
673 {
674 	dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name,
675 		inode->i_ino, dentry, size);
676 
677 	name = xattr_full_name(handler, name);
678 	return ubifs_xattr_get(inode, name, buffer, size);
679 }
680 
681 static int xattr_set(const struct xattr_handler *handler,
682 			   struct dentry *dentry, struct inode *inode,
683 			   const char *name, const void *value,
684 			   size_t size, int flags)
685 {
686 	dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd",
687 		name, inode->i_ino, dentry, size);
688 
689 	name = xattr_full_name(handler, name);
690 
691 	if (value)
692 		return ubifs_xattr_set(inode, name, value, size, flags, true);
693 	else
694 		return ubifs_xattr_remove(inode, name);
695 }
696 
697 static const struct xattr_handler ubifs_user_xattr_handler = {
698 	.prefix = XATTR_USER_PREFIX,
699 	.get = xattr_get,
700 	.set = xattr_set,
701 };
702 
703 static const struct xattr_handler ubifs_trusted_xattr_handler = {
704 	.prefix = XATTR_TRUSTED_PREFIX,
705 	.get = xattr_get,
706 	.set = xattr_set,
707 };
708 
709 #ifdef CONFIG_UBIFS_FS_SECURITY
710 static const struct xattr_handler ubifs_security_xattr_handler = {
711 	.prefix = XATTR_SECURITY_PREFIX,
712 	.get = xattr_get,
713 	.set = xattr_set,
714 };
715 #endif
716 
717 const struct xattr_handler *ubifs_xattr_handlers[] = {
718 	&ubifs_user_xattr_handler,
719 	&ubifs_trusted_xattr_handler,
720 #ifdef CONFIG_UBIFS_FS_SECURITY
721 	&ubifs_security_xattr_handler,
722 #endif
723 	NULL
724 };
725