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TOMOYO Linux Cross Reference
Linux/fs/ubifs/xattr.c

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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  */
 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 

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