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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 */
58enum {
59 USER_XATTR,
60 TRUSTED_XATTR,
61 SECURITY_XATTR,
62};
63
64static const struct inode_operations empty_iops;
65static 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 */
81static 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
163out_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);
170out_free:
171 make_bad_inode(inode);
172 iput(inode);
173out_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 */
190static 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
238out_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);
243out_free:
244 ubifs_release_budget(c, &req);
245 return err;
246}
247
248static 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
265int 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
321out_free:
322 kfree(xent);
323 return err;
324}
325
326ssize_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
374out_iput:
375 mutex_unlock(&ui->ui_mutex);
376 iput(inode);
377out_unlock:
378 kfree(xent);
379 return err;
380}
381
382static 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
396ssize_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
451static 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
481out_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
492int 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 */
566void 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
577static 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
618out_free:
619 kfree(xent);
620 return err;
621}
622
623#ifdef CONFIG_UBIFS_FS_SECURITY
624static 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
654int 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
670static 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
681static 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
697static const struct xattr_handler ubifs_user_xattr_handler = {
698 .prefix = XATTR_USER_PREFIX,
699 .get = xattr_get,
700 .set = xattr_set,
701};
702
703static 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
710static 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
717const 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};
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 */
58enum {
59 USER_XATTR,
60 TRUSTED_XATTR,
61 SECURITY_XATTR,
62};
63
64static const struct inode_operations empty_iops;
65static 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 */
81static 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, true);
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 inode_set_ctime_current(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
163out_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);
170out_free:
171 make_bad_inode(inode);
172 iput(inode);
173out_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 */
190static 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 kfree(ui->data);
212 ui->data = buf;
213 inode->i_size = ui->ui_size = size;
214 old_size = ui->data_len;
215 ui->data_len = size;
216
217 mutex_lock(&host_ui->ui_mutex);
218 inode_set_ctime_current(host);
219 host_ui->xattr_size -= CALC_XATTR_BYTES(old_size);
220 host_ui->xattr_size += CALC_XATTR_BYTES(size);
221
222 /*
223 * It is important to write the host inode after the xattr inode
224 * because if the host inode gets synchronized (via 'fsync()'), then
225 * the extended attribute inode gets synchronized, because it goes
226 * before the host inode in the write-buffer.
227 */
228 err = ubifs_jnl_change_xattr(c, inode, host);
229 if (err)
230 goto out_cancel;
231 mutex_unlock(&host_ui->ui_mutex);
232
233 ubifs_release_budget(c, &req);
234 return 0;
235
236out_cancel:
237 host_ui->xattr_size -= CALC_XATTR_BYTES(size);
238 host_ui->xattr_size += CALC_XATTR_BYTES(old_size);
239 mutex_unlock(&host_ui->ui_mutex);
240 make_bad_inode(inode);
241out_free:
242 ubifs_release_budget(c, &req);
243 return err;
244}
245
246static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
247{
248 struct inode *inode;
249
250 inode = ubifs_iget(c->vfs_sb, inum);
251 if (IS_ERR(inode)) {
252 ubifs_err(c, "dead extended attribute entry, error %d",
253 (int)PTR_ERR(inode));
254 return inode;
255 }
256 if (ubifs_inode(inode)->xattr)
257 return inode;
258 ubifs_err(c, "corrupt extended attribute entry");
259 iput(inode);
260 return ERR_PTR(-EINVAL);
261}
262
263int ubifs_xattr_set(struct inode *host, const char *name, const void *value,
264 size_t size, int flags, bool check_lock)
265{
266 struct inode *inode;
267 struct ubifs_info *c = host->i_sb->s_fs_info;
268 struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
269 struct ubifs_dent_node *xent;
270 union ubifs_key key;
271 int err;
272
273 if (check_lock)
274 ubifs_assert(c, inode_is_locked(host));
275
276 if (size > UBIFS_MAX_INO_DATA)
277 return -ERANGE;
278
279 if (fname_len(&nm) > UBIFS_MAX_NLEN)
280 return -ENAMETOOLONG;
281
282 xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
283 if (!xent)
284 return -ENOMEM;
285
286 down_write(&ubifs_inode(host)->xattr_sem);
287 /*
288 * The extended attribute entries are stored in LNC, so multiple
289 * look-ups do not involve reading the flash.
290 */
291 xent_key_init(c, &key, host->i_ino, &nm);
292 err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
293 if (err) {
294 if (err != -ENOENT)
295 goto out_free;
296
297 if (flags & XATTR_REPLACE)
298 /* We are asked not to create the xattr */
299 err = -ENODATA;
300 else
301 err = create_xattr(c, host, &nm, value, size);
302 goto out_free;
303 }
304
305 if (flags & XATTR_CREATE) {
306 /* We are asked not to replace the xattr */
307 err = -EEXIST;
308 goto out_free;
309 }
310
311 inode = iget_xattr(c, le64_to_cpu(xent->inum));
312 if (IS_ERR(inode)) {
313 err = PTR_ERR(inode);
314 goto out_free;
315 }
316
317 err = change_xattr(c, host, inode, value, size);
318 iput(inode);
319
320out_free:
321 up_write(&ubifs_inode(host)->xattr_sem);
322 kfree(xent);
323 return err;
324}
325
326ssize_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 down_read(&ubifs_inode(host)->xattr_sem);
345 xent_key_init(c, &key, host->i_ino, &nm);
346 err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
347 if (err) {
348 if (err == -ENOENT)
349 err = -ENODATA;
350 goto out_cleanup;
351 }
352
353 inode = iget_xattr(c, le64_to_cpu(xent->inum));
354 if (IS_ERR(inode)) {
355 err = PTR_ERR(inode);
356 goto out_cleanup;
357 }
358
359 ui = ubifs_inode(inode);
360 ubifs_assert(c, inode->i_size == ui->data_len);
361 ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len);
362
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
374out_iput:
375 iput(inode);
376out_cleanup:
377 up_read(&ubifs_inode(host)->xattr_sem);
378 kfree(xent);
379 return err;
380}
381
382static 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
396ssize_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 down_read(&host_ui->xattr_sem);
410 len = host_ui->xattr_names + host_ui->xattr_cnt;
411 if (!buffer) {
412 /*
413 * We should return the minimum buffer size which will fit a
414 * null-terminated list of all the extended attribute names.
415 */
416 err = len;
417 goto out_err;
418 }
419
420 if (len > size) {
421 err = -ERANGE;
422 goto out_err;
423 }
424
425 lowest_xent_key(c, &key, host->i_ino);
426 while (1) {
427 xent = ubifs_tnc_next_ent(c, &key, &nm);
428 if (IS_ERR(xent)) {
429 err = PTR_ERR(xent);
430 break;
431 }
432
433 fname_name(&nm) = xent->name;
434 fname_len(&nm) = le16_to_cpu(xent->nlen);
435
436 if (xattr_visible(xent->name)) {
437 memcpy(buffer + written, fname_name(&nm), fname_len(&nm) + 1);
438 written += fname_len(&nm) + 1;
439 }
440
441 kfree(pxent);
442 pxent = xent;
443 key_read(c, &xent->key, &key);
444 }
445 kfree(pxent);
446 up_read(&host_ui->xattr_sem);
447
448 if (err != -ENOENT) {
449 ubifs_err(c, "cannot find next direntry, error %d", err);
450 return err;
451 }
452
453 ubifs_assert(c, written <= size);
454 return written;
455
456out_err:
457 up_read(&host_ui->xattr_sem);
458 return err;
459}
460
461static int remove_xattr(struct ubifs_info *c, struct inode *host,
462 struct inode *inode, const struct fscrypt_name *nm)
463{
464 int err;
465 struct ubifs_inode *host_ui = ubifs_inode(host);
466 struct ubifs_inode *ui = ubifs_inode(inode);
467 struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1,
468 .dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
469
470 ubifs_assert(c, ui->data_len == inode->i_size);
471
472 err = ubifs_budget_space(c, &req);
473 if (err)
474 return err;
475
476 mutex_lock(&host_ui->ui_mutex);
477 inode_set_ctime_current(host);
478 host_ui->xattr_cnt -= 1;
479 host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm));
480 host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
481 host_ui->xattr_names -= fname_len(nm);
482
483 err = ubifs_jnl_delete_xattr(c, host, inode, nm);
484 if (err)
485 goto out_cancel;
486 mutex_unlock(&host_ui->ui_mutex);
487
488 ubifs_release_budget(c, &req);
489 return 0;
490
491out_cancel:
492 host_ui->xattr_cnt += 1;
493 host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm));
494 host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
495 host_ui->xattr_names += fname_len(nm);
496 mutex_unlock(&host_ui->ui_mutex);
497 ubifs_release_budget(c, &req);
498 make_bad_inode(inode);
499 return err;
500}
501
502int ubifs_purge_xattrs(struct inode *host)
503{
504 union ubifs_key key;
505 struct ubifs_info *c = host->i_sb->s_fs_info;
506 struct ubifs_dent_node *xent, *pxent = NULL;
507 struct inode *xino;
508 struct fscrypt_name nm = {0};
509 int err;
510
511 if (ubifs_inode(host)->xattr_cnt <= ubifs_xattr_max_cnt(c))
512 return 0;
513
514 ubifs_warn(c, "inode %lu has too many xattrs, doing a non-atomic deletion",
515 host->i_ino);
516
517 down_write(&ubifs_inode(host)->xattr_sem);
518 lowest_xent_key(c, &key, host->i_ino);
519 while (1) {
520 xent = ubifs_tnc_next_ent(c, &key, &nm);
521 if (IS_ERR(xent)) {
522 err = PTR_ERR(xent);
523 break;
524 }
525
526 fname_name(&nm) = xent->name;
527 fname_len(&nm) = le16_to_cpu(xent->nlen);
528
529 xino = ubifs_iget(c->vfs_sb, le64_to_cpu(xent->inum));
530 if (IS_ERR(xino)) {
531 err = PTR_ERR(xino);
532 ubifs_err(c, "dead directory entry '%s', error %d",
533 xent->name, err);
534 ubifs_ro_mode(c, err);
535 kfree(pxent);
536 kfree(xent);
537 goto out_err;
538 }
539
540 ubifs_assert(c, ubifs_inode(xino)->xattr);
541
542 clear_nlink(xino);
543 err = remove_xattr(c, host, xino, &nm);
544 if (err) {
545 kfree(pxent);
546 kfree(xent);
547 iput(xino);
548 ubifs_err(c, "cannot remove xattr, error %d", err);
549 goto out_err;
550 }
551
552 iput(xino);
553
554 kfree(pxent);
555 pxent = xent;
556 key_read(c, &xent->key, &key);
557 }
558 kfree(pxent);
559 up_write(&ubifs_inode(host)->xattr_sem);
560
561 if (err != -ENOENT) {
562 ubifs_err(c, "cannot find next direntry, error %d", err);
563 return err;
564 }
565
566 return 0;
567
568out_err:
569 up_write(&ubifs_inode(host)->xattr_sem);
570 return err;
571}
572
573/**
574 * ubifs_evict_xattr_inode - Evict an xattr inode.
575 * @c: UBIFS file-system description object
576 * @xattr_inum: xattr inode number
577 *
578 * When an inode that hosts xattrs is being removed we have to make sure
579 * that cached inodes of the xattrs also get removed from the inode cache
580 * otherwise we'd waste memory. This function looks up an inode from the
581 * inode cache and clears the link counter such that iput() will evict
582 * the inode.
583 */
584void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum)
585{
586 struct inode *inode;
587
588 inode = ilookup(c->vfs_sb, xattr_inum);
589 if (inode) {
590 clear_nlink(inode);
591 iput(inode);
592 }
593}
594
595static int ubifs_xattr_remove(struct inode *host, const char *name)
596{
597 struct inode *inode;
598 struct ubifs_info *c = host->i_sb->s_fs_info;
599 struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))};
600 struct ubifs_dent_node *xent;
601 union ubifs_key key;
602 int err;
603
604 ubifs_assert(c, inode_is_locked(host));
605
606 if (fname_len(&nm) > UBIFS_MAX_NLEN)
607 return -ENAMETOOLONG;
608
609 xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
610 if (!xent)
611 return -ENOMEM;
612
613 down_write(&ubifs_inode(host)->xattr_sem);
614 xent_key_init(c, &key, host->i_ino, &nm);
615 err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
616 if (err) {
617 if (err == -ENOENT)
618 err = -ENODATA;
619 goto out_free;
620 }
621
622 inode = iget_xattr(c, le64_to_cpu(xent->inum));
623 if (IS_ERR(inode)) {
624 err = PTR_ERR(inode);
625 goto out_free;
626 }
627
628 ubifs_assert(c, inode->i_nlink == 1);
629 clear_nlink(inode);
630 err = remove_xattr(c, host, inode, &nm);
631 if (err)
632 set_nlink(inode, 1);
633
634 /* If @i_nlink is 0, 'iput()' will delete the inode */
635 iput(inode);
636
637out_free:
638 up_write(&ubifs_inode(host)->xattr_sem);
639 kfree(xent);
640 return err;
641}
642
643#ifdef CONFIG_UBIFS_FS_SECURITY
644static int init_xattrs(struct inode *inode, const struct xattr *xattr_array,
645 void *fs_info)
646{
647 const struct xattr *xattr;
648 char *name;
649 int err = 0;
650
651 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
652 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
653 strlen(xattr->name) + 1, GFP_NOFS);
654 if (!name) {
655 err = -ENOMEM;
656 break;
657 }
658 strcpy(name, XATTR_SECURITY_PREFIX);
659 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
660 /*
661 * creating a new inode without holding the inode rwsem,
662 * no need to check whether inode is locked.
663 */
664 err = ubifs_xattr_set(inode, name, xattr->value,
665 xattr->value_len, 0, false);
666 kfree(name);
667 if (err < 0)
668 break;
669 }
670
671 return err;
672}
673
674int ubifs_init_security(struct inode *dentry, struct inode *inode,
675 const struct qstr *qstr)
676{
677 int err;
678
679 err = security_inode_init_security(inode, dentry, qstr,
680 &init_xattrs, NULL);
681 if (err) {
682 struct ubifs_info *c = dentry->i_sb->s_fs_info;
683 ubifs_err(c, "cannot initialize security for inode %lu, error %d",
684 inode->i_ino, err);
685 }
686 return err;
687}
688#endif
689
690static int xattr_get(const struct xattr_handler *handler,
691 struct dentry *dentry, struct inode *inode,
692 const char *name, void *buffer, size_t size)
693{
694 dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name,
695 inode->i_ino, dentry, size);
696
697 name = xattr_full_name(handler, name);
698 return ubifs_xattr_get(inode, name, buffer, size);
699}
700
701static int xattr_set(const struct xattr_handler *handler,
702 struct mnt_idmap *idmap,
703 struct dentry *dentry, struct inode *inode,
704 const char *name, const void *value,
705 size_t size, int flags)
706{
707 dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd",
708 name, inode->i_ino, dentry, size);
709
710 name = xattr_full_name(handler, name);
711
712 if (value)
713 return ubifs_xattr_set(inode, name, value, size, flags, true);
714 else
715 return ubifs_xattr_remove(inode, name);
716}
717
718static const struct xattr_handler ubifs_user_xattr_handler = {
719 .prefix = XATTR_USER_PREFIX,
720 .get = xattr_get,
721 .set = xattr_set,
722};
723
724static const struct xattr_handler ubifs_trusted_xattr_handler = {
725 .prefix = XATTR_TRUSTED_PREFIX,
726 .get = xattr_get,
727 .set = xattr_set,
728};
729
730#ifdef CONFIG_UBIFS_FS_SECURITY
731static const struct xattr_handler ubifs_security_xattr_handler = {
732 .prefix = XATTR_SECURITY_PREFIX,
733 .get = xattr_get,
734 .set = xattr_set,
735};
736#endif
737
738const struct xattr_handler * const ubifs_xattr_handlers[] = {
739 &ubifs_user_xattr_handler,
740 &ubifs_trusted_xattr_handler,
741#ifdef CONFIG_UBIFS_FS_SECURITY
742 &ubifs_security_xattr_handler,
743#endif
744 NULL
745};