Commit | Line | Data |
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1e51764a AB |
1 | /* |
2 | * This file is part of UBIFS. | |
3 | * | |
4 | * Copyright (C) 2006-2008 Nokia Corporation. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License version 2 as published by | |
8 | * the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
13 | * more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License along with | |
16 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
17 | * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
18 | * | |
19 | * Authors: Artem Bityutskiy (Битюцкий Артём) | |
20 | * Adrian Hunter | |
21 | */ | |
22 | ||
23 | /* | |
24 | * This file implements UBIFS extended attributes support. | |
25 | * | |
26 | * Extended attributes are implemented as regular inodes with attached data, | |
27 | * which limits extended attribute size to UBIFS block size (4KiB). Names of | |
28 | * extended attributes are described by extended attribute entries (xentries), | |
29 | * which are almost identical to directory entries, but have different key type. | |
30 | * | |
31 | * In other words, the situation with extended attributes is very similar to | |
32 | * directories. Indeed, any inode (but of course not xattr inodes) may have a | |
33 | * number of associated xentries, just like directory inodes have associated | |
34 | * directory entries. Extended attribute entries store the name of the extended | |
35 | * attribute, the host inode number, and the extended attribute inode number. | |
36 | * Similarly, direntries store the name, the parent and the target inode | |
37 | * numbers. Thus, most of the common UBIFS mechanisms may be re-used for | |
38 | * extended attributes. | |
39 | * | |
40 | * The number of extended attributes is not limited, but there is Linux | |
41 | * limitation on the maximum possible size of the list of all extended | |
42 | * attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure | |
43 | * the sum of all extended attribute names of the inode does not exceed that | |
44 | * limit. | |
45 | * | |
46 | * Extended attributes are synchronous, which means they are written to the | |
47 | * flash media synchronously and there is no write-back for extended attribute | |
48 | * inodes. The extended attribute values are not stored in compressed form on | |
49 | * the media. | |
50 | * | |
51 | * Since extended attributes are represented by regular inodes, they are cached | |
52 | * in the VFS inode cache. The xentries are cached in the LNC cache (see | |
53 | * tnc.c). | |
54 | * | |
55 | * ACL support is not implemented. | |
56 | */ | |
57 | ||
073aaa1b | 58 | #include "ubifs.h" |
7dcda1c9 | 59 | #include <linux/fs.h> |
5a0e3ad6 | 60 | #include <linux/slab.h> |
1e51764a AB |
61 | #include <linux/xattr.h> |
62 | #include <linux/posix_acl_xattr.h> | |
1e51764a AB |
63 | |
64 | /* | |
65 | * Limit the number of extended attributes per inode so that the total size | |
c78c7e35 | 66 | * (@xattr_size) is guaranteeded to fit in an 'unsigned int'. |
1e51764a AB |
67 | */ |
68 | #define MAX_XATTRS_PER_INODE 65535 | |
69 | ||
70 | /* | |
71 | * Extended attribute type constants. | |
72 | * | |
73 | * USER_XATTR: user extended attribute ("user.*") | |
74 | * TRUSTED_XATTR: trusted extended attribute ("trusted.*) | |
75 | * SECURITY_XATTR: security extended attribute ("security.*") | |
76 | */ | |
77 | enum { | |
78 | USER_XATTR, | |
79 | TRUSTED_XATTR, | |
80 | SECURITY_XATTR, | |
81 | }; | |
82 | ||
8c6866b0 | 83 | static const struct inode_operations none_inode_operations; |
8c6866b0 | 84 | static const struct file_operations none_file_operations; |
1e51764a AB |
85 | |
86 | /** | |
87 | * create_xattr - create an extended attribute. | |
88 | * @c: UBIFS file-system description object | |
89 | * @host: host inode | |
90 | * @nm: extended attribute name | |
91 | * @value: extended attribute value | |
92 | * @size: size of extended attribute value | |
93 | * | |
94 | * This is a helper function which creates an extended attribute of name @nm | |
95 | * and value @value for inode @host. The host inode is also updated on flash | |
96 | * because the ctime and extended attribute accounting data changes. This | |
97 | * function returns zero in case of success and a negative error code in case | |
98 | * of failure. | |
99 | */ | |
100 | static int create_xattr(struct ubifs_info *c, struct inode *host, | |
101 | const struct qstr *nm, const void *value, int size) | |
102 | { | |
103 | int err; | |
104 | struct inode *inode; | |
105 | struct ubifs_inode *ui, *host_ui = ubifs_inode(host); | |
106 | struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, | |
5acd6ff8 ZS |
107 | .new_ino_d = ALIGN(size, 8), .dirtied_ino = 1, |
108 | .dirtied_ino_d = ALIGN(host_ui->data_len, 8) }; | |
1e51764a AB |
109 | |
110 | if (host_ui->xattr_cnt >= MAX_XATTRS_PER_INODE) | |
111 | return -ENOSPC; | |
112 | /* | |
113 | * Linux limits the maximum size of the extended attribute names list | |
c78c7e35 | 114 | * to %XATTR_LIST_MAX. This means we should not allow creating more |
1e51764a AB |
115 | * extended attributes if the name list becomes larger. This limitation |
116 | * is artificial for UBIFS, though. | |
117 | */ | |
118 | if (host_ui->xattr_names + host_ui->xattr_cnt + | |
119 | nm->len + 1 > XATTR_LIST_MAX) | |
120 | return -ENOSPC; | |
121 | ||
122 | err = ubifs_budget_space(c, &req); | |
123 | if (err) | |
124 | return err; | |
125 | ||
126 | inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO); | |
127 | if (IS_ERR(inode)) { | |
128 | err = PTR_ERR(inode); | |
129 | goto out_budg; | |
130 | } | |
131 | ||
1e51764a | 132 | /* Re-define all operations to be "nothing" */ |
7dcda1c9 | 133 | inode->i_mapping->a_ops = &empty_aops; |
1e51764a AB |
134 | inode->i_op = &none_inode_operations; |
135 | inode->i_fop = &none_file_operations; | |
136 | ||
137 | inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME | S_NOQUOTA; | |
138 | ui = ubifs_inode(inode); | |
139 | ui->xattr = 1; | |
140 | ui->flags |= UBIFS_XATTR_FL; | |
141 | ui->data = kmalloc(size, GFP_NOFS); | |
142 | if (!ui->data) { | |
143 | err = -ENOMEM; | |
c78c7e35 | 144 | goto out_free; |
1e51764a | 145 | } |
1e51764a | 146 | memcpy(ui->data, value, size); |
c78c7e35 AB |
147 | inode->i_size = ui->ui_size = size; |
148 | ui->data_len = size; | |
149 | ||
150 | mutex_lock(&host_ui->ui_mutex); | |
1e51764a AB |
151 | host->i_ctime = ubifs_current_time(host); |
152 | host_ui->xattr_cnt += 1; | |
153 | host_ui->xattr_size += CALC_DENT_SIZE(nm->len); | |
154 | host_ui->xattr_size += CALC_XATTR_BYTES(size); | |
155 | host_ui->xattr_names += nm->len; | |
156 | ||
1e51764a AB |
157 | err = ubifs_jnl_update(c, host, nm, inode, 0, 1); |
158 | if (err) | |
159 | goto out_cancel; | |
160 | mutex_unlock(&host_ui->ui_mutex); | |
161 | ||
162 | ubifs_release_budget(c, &req); | |
163 | insert_inode_hash(inode); | |
164 | iput(inode); | |
165 | return 0; | |
166 | ||
167 | out_cancel: | |
168 | host_ui->xattr_cnt -= 1; | |
169 | host_ui->xattr_size -= CALC_DENT_SIZE(nm->len); | |
170 | host_ui->xattr_size -= CALC_XATTR_BYTES(size); | |
1e51764a | 171 | mutex_unlock(&host_ui->ui_mutex); |
c78c7e35 | 172 | out_free: |
1e51764a AB |
173 | make_bad_inode(inode); |
174 | iput(inode); | |
175 | out_budg: | |
176 | ubifs_release_budget(c, &req); | |
177 | return err; | |
178 | } | |
179 | ||
180 | /** | |
181 | * change_xattr - change an extended attribute. | |
182 | * @c: UBIFS file-system description object | |
183 | * @host: host inode | |
184 | * @inode: extended attribute inode | |
185 | * @value: extended attribute value | |
186 | * @size: size of extended attribute value | |
187 | * | |
188 | * This helper function changes the value of extended attribute @inode with new | |
189 | * data from @value. Returns zero in case of success and a negative error code | |
190 | * in case of failure. | |
191 | */ | |
192 | static int change_xattr(struct ubifs_info *c, struct inode *host, | |
193 | struct inode *inode, const void *value, int size) | |
194 | { | |
195 | int err; | |
196 | struct ubifs_inode *host_ui = ubifs_inode(host); | |
197 | struct ubifs_inode *ui = ubifs_inode(inode); | |
198 | struct ubifs_budget_req req = { .dirtied_ino = 2, | |
5acd6ff8 | 199 | .dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) }; |
1e51764a AB |
200 | |
201 | ubifs_assert(ui->data_len == inode->i_size); | |
202 | err = ubifs_budget_space(c, &req); | |
203 | if (err) | |
204 | return err; | |
205 | ||
1e51764a AB |
206 | kfree(ui->data); |
207 | ui->data = kmalloc(size, GFP_NOFS); | |
208 | if (!ui->data) { | |
209 | err = -ENOMEM; | |
c78c7e35 | 210 | goto out_free; |
1e51764a | 211 | } |
1e51764a AB |
212 | memcpy(ui->data, value, size); |
213 | inode->i_size = ui->ui_size = size; | |
214 | ui->data_len = size; | |
215 | ||
c78c7e35 AB |
216 | mutex_lock(&host_ui->ui_mutex); |
217 | host->i_ctime = ubifs_current_time(host); | |
218 | host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len); | |
219 | host_ui->xattr_size += CALC_XATTR_BYTES(size); | |
220 | ||
1e51764a AB |
221 | /* |
222 | * It is important to write the host inode after the xattr inode | |
223 | * because if the host inode gets synchronized (via 'fsync()'), then | |
224 | * the extended attribute inode gets synchronized, because it goes | |
225 | * before the host inode in the write-buffer. | |
226 | */ | |
227 | err = ubifs_jnl_change_xattr(c, inode, host); | |
228 | if (err) | |
229 | goto out_cancel; | |
230 | mutex_unlock(&host_ui->ui_mutex); | |
231 | ||
232 | ubifs_release_budget(c, &req); | |
233 | return 0; | |
234 | ||
235 | out_cancel: | |
236 | host_ui->xattr_size -= CALC_XATTR_BYTES(size); | |
237 | host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len); | |
1e51764a | 238 | mutex_unlock(&host_ui->ui_mutex); |
c78c7e35 AB |
239 | make_bad_inode(inode); |
240 | out_free: | |
1e51764a AB |
241 | ubifs_release_budget(c, &req); |
242 | return err; | |
243 | } | |
244 | ||
245 | /** | |
246 | * check_namespace - check extended attribute name-space. | |
247 | * @nm: extended attribute name | |
248 | * | |
249 | * This function makes sure the extended attribute name belongs to one of the | |
250 | * supported extended attribute name-spaces. Returns name-space index in case | |
251 | * of success and a negative error code in case of failure. | |
252 | */ | |
253 | static int check_namespace(const struct qstr *nm) | |
254 | { | |
255 | int type; | |
256 | ||
257 | if (nm->len > UBIFS_MAX_NLEN) | |
258 | return -ENAMETOOLONG; | |
259 | ||
260 | if (!strncmp(nm->name, XATTR_TRUSTED_PREFIX, | |
261 | XATTR_TRUSTED_PREFIX_LEN)) { | |
262 | if (nm->name[sizeof(XATTR_TRUSTED_PREFIX) - 1] == '\0') | |
263 | return -EINVAL; | |
264 | type = TRUSTED_XATTR; | |
265 | } else if (!strncmp(nm->name, XATTR_USER_PREFIX, | |
266 | XATTR_USER_PREFIX_LEN)) { | |
267 | if (nm->name[XATTR_USER_PREFIX_LEN] == '\0') | |
268 | return -EINVAL; | |
269 | type = USER_XATTR; | |
270 | } else if (!strncmp(nm->name, XATTR_SECURITY_PREFIX, | |
271 | XATTR_SECURITY_PREFIX_LEN)) { | |
272 | if (nm->name[sizeof(XATTR_SECURITY_PREFIX) - 1] == '\0') | |
273 | return -EINVAL; | |
274 | type = SECURITY_XATTR; | |
275 | } else | |
276 | return -EOPNOTSUPP; | |
277 | ||
278 | return type; | |
279 | } | |
280 | ||
281 | static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum) | |
282 | { | |
283 | struct inode *inode; | |
284 | ||
285 | inode = ubifs_iget(c->vfs_sb, inum); | |
286 | if (IS_ERR(inode)) { | |
287 | ubifs_err("dead extended attribute entry, error %d", | |
288 | (int)PTR_ERR(inode)); | |
289 | return inode; | |
290 | } | |
291 | if (ubifs_inode(inode)->xattr) | |
292 | return inode; | |
293 | ubifs_err("corrupt extended attribute entry"); | |
294 | iput(inode); | |
295 | return ERR_PTR(-EINVAL); | |
296 | } | |
297 | ||
298 | int ubifs_setxattr(struct dentry *dentry, const char *name, | |
299 | const void *value, size_t size, int flags) | |
300 | { | |
301 | struct inode *inode, *host = dentry->d_inode; | |
302 | struct ubifs_info *c = host->i_sb->s_fs_info; | |
303 | struct qstr nm = { .name = name, .len = strlen(name) }; | |
304 | struct ubifs_dent_node *xent; | |
305 | union ubifs_key key; | |
306 | int err, type; | |
307 | ||
308 | dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name, | |
309 | host->i_ino, dentry->d_name.len, dentry->d_name.name, size); | |
c78c7e35 | 310 | ubifs_assert(mutex_is_locked(&host->i_mutex)); |
1e51764a AB |
311 | |
312 | if (size > UBIFS_MAX_INO_DATA) | |
313 | return -ERANGE; | |
314 | ||
315 | type = check_namespace(&nm); | |
316 | if (type < 0) | |
317 | return type; | |
318 | ||
319 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
320 | if (!xent) | |
321 | return -ENOMEM; | |
322 | ||
323 | /* | |
324 | * The extended attribute entries are stored in LNC, so multiple | |
325 | * look-ups do not involve reading the flash. | |
326 | */ | |
327 | xent_key_init(c, &key, host->i_ino, &nm); | |
328 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
329 | if (err) { | |
330 | if (err != -ENOENT) | |
331 | goto out_free; | |
332 | ||
333 | if (flags & XATTR_REPLACE) | |
334 | /* We are asked not to create the xattr */ | |
335 | err = -ENODATA; | |
336 | else | |
337 | err = create_xattr(c, host, &nm, value, size); | |
338 | goto out_free; | |
339 | } | |
340 | ||
341 | if (flags & XATTR_CREATE) { | |
342 | /* We are asked not to replace the xattr */ | |
343 | err = -EEXIST; | |
344 | goto out_free; | |
345 | } | |
346 | ||
347 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
348 | if (IS_ERR(inode)) { | |
349 | err = PTR_ERR(inode); | |
350 | goto out_free; | |
351 | } | |
352 | ||
353 | err = change_xattr(c, host, inode, value, size); | |
354 | iput(inode); | |
355 | ||
356 | out_free: | |
357 | kfree(xent); | |
358 | return err; | |
359 | } | |
360 | ||
361 | ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf, | |
362 | size_t size) | |
363 | { | |
364 | struct inode *inode, *host = dentry->d_inode; | |
365 | struct ubifs_info *c = host->i_sb->s_fs_info; | |
366 | struct qstr nm = { .name = name, .len = strlen(name) }; | |
367 | struct ubifs_inode *ui; | |
368 | struct ubifs_dent_node *xent; | |
369 | union ubifs_key key; | |
370 | int err; | |
371 | ||
372 | dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name, | |
373 | host->i_ino, dentry->d_name.len, dentry->d_name.name, size); | |
374 | ||
375 | err = check_namespace(&nm); | |
376 | if (err < 0) | |
377 | return err; | |
378 | ||
379 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
380 | if (!xent) | |
381 | return -ENOMEM; | |
382 | ||
1e51764a AB |
383 | xent_key_init(c, &key, host->i_ino, &nm); |
384 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
385 | if (err) { | |
386 | if (err == -ENOENT) | |
387 | err = -ENODATA; | |
388 | goto out_unlock; | |
389 | } | |
390 | ||
391 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
392 | if (IS_ERR(inode)) { | |
393 | err = PTR_ERR(inode); | |
394 | goto out_unlock; | |
395 | } | |
396 | ||
397 | ui = ubifs_inode(inode); | |
398 | ubifs_assert(inode->i_size == ui->data_len); | |
399 | ubifs_assert(ubifs_inode(host)->xattr_size > ui->data_len); | |
400 | ||
401 | if (buf) { | |
402 | /* If @buf is %NULL we are supposed to return the length */ | |
403 | if (ui->data_len > size) { | |
404 | dbg_err("buffer size %zd, xattr len %d", | |
405 | size, ui->data_len); | |
406 | err = -ERANGE; | |
407 | goto out_iput; | |
408 | } | |
409 | ||
410 | memcpy(buf, ui->data, ui->data_len); | |
411 | } | |
412 | err = ui->data_len; | |
413 | ||
414 | out_iput: | |
415 | iput(inode); | |
416 | out_unlock: | |
1e51764a AB |
417 | kfree(xent); |
418 | return err; | |
419 | } | |
420 | ||
421 | ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size) | |
422 | { | |
423 | union ubifs_key key; | |
424 | struct inode *host = dentry->d_inode; | |
425 | struct ubifs_info *c = host->i_sb->s_fs_info; | |
426 | struct ubifs_inode *host_ui = ubifs_inode(host); | |
427 | struct ubifs_dent_node *xent, *pxent = NULL; | |
428 | int err, len, written = 0; | |
429 | struct qstr nm = { .name = NULL }; | |
430 | ||
431 | dbg_gen("ino %lu ('%.*s'), buffer size %zd", host->i_ino, | |
432 | dentry->d_name.len, dentry->d_name.name, size); | |
433 | ||
434 | len = host_ui->xattr_names + host_ui->xattr_cnt; | |
435 | if (!buffer) | |
436 | /* | |
437 | * We should return the minimum buffer size which will fit a | |
438 | * null-terminated list of all the extended attribute names. | |
439 | */ | |
440 | return len; | |
441 | ||
442 | if (len > size) | |
443 | return -ERANGE; | |
444 | ||
445 | lowest_xent_key(c, &key, host->i_ino); | |
1e51764a AB |
446 | while (1) { |
447 | int type; | |
448 | ||
449 | xent = ubifs_tnc_next_ent(c, &key, &nm); | |
8d47aef4 | 450 | if (IS_ERR(xent)) { |
1e51764a AB |
451 | err = PTR_ERR(xent); |
452 | break; | |
453 | } | |
454 | ||
455 | nm.name = xent->name; | |
456 | nm.len = le16_to_cpu(xent->nlen); | |
457 | ||
458 | type = check_namespace(&nm); | |
459 | if (unlikely(type < 0)) { | |
460 | err = type; | |
461 | break; | |
462 | } | |
463 | ||
464 | /* Show trusted namespace only for "power" users */ | |
465 | if (type != TRUSTED_XATTR || capable(CAP_SYS_ADMIN)) { | |
466 | memcpy(buffer + written, nm.name, nm.len + 1); | |
467 | written += nm.len + 1; | |
468 | } | |
469 | ||
470 | kfree(pxent); | |
471 | pxent = xent; | |
472 | key_read(c, &xent->key, &key); | |
473 | } | |
1e51764a AB |
474 | |
475 | kfree(pxent); | |
476 | if (err != -ENOENT) { | |
477 | ubifs_err("cannot find next direntry, error %d", err); | |
478 | return err; | |
479 | } | |
480 | ||
481 | ubifs_assert(written <= size); | |
482 | return written; | |
483 | } | |
484 | ||
485 | static int remove_xattr(struct ubifs_info *c, struct inode *host, | |
486 | struct inode *inode, const struct qstr *nm) | |
487 | { | |
488 | int err; | |
489 | struct ubifs_inode *host_ui = ubifs_inode(host); | |
490 | struct ubifs_inode *ui = ubifs_inode(inode); | |
5acd6ff8 ZS |
491 | struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1, |
492 | .dirtied_ino_d = ALIGN(host_ui->data_len, 8) }; | |
1e51764a AB |
493 | |
494 | ubifs_assert(ui->data_len == inode->i_size); | |
495 | ||
496 | err = ubifs_budget_space(c, &req); | |
497 | if (err) | |
498 | return err; | |
499 | ||
500 | mutex_lock(&host_ui->ui_mutex); | |
501 | host->i_ctime = ubifs_current_time(host); | |
502 | host_ui->xattr_cnt -= 1; | |
503 | host_ui->xattr_size -= CALC_DENT_SIZE(nm->len); | |
504 | host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len); | |
505 | host_ui->xattr_names -= nm->len; | |
506 | ||
507 | err = ubifs_jnl_delete_xattr(c, host, inode, nm); | |
508 | if (err) | |
509 | goto out_cancel; | |
510 | mutex_unlock(&host_ui->ui_mutex); | |
511 | ||
512 | ubifs_release_budget(c, &req); | |
513 | return 0; | |
514 | ||
515 | out_cancel: | |
516 | host_ui->xattr_cnt += 1; | |
517 | host_ui->xattr_size += CALC_DENT_SIZE(nm->len); | |
518 | host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len); | |
519 | mutex_unlock(&host_ui->ui_mutex); | |
520 | ubifs_release_budget(c, &req); | |
521 | make_bad_inode(inode); | |
522 | return err; | |
523 | } | |
524 | ||
525 | int ubifs_removexattr(struct dentry *dentry, const char *name) | |
526 | { | |
527 | struct inode *inode, *host = dentry->d_inode; | |
528 | struct ubifs_info *c = host->i_sb->s_fs_info; | |
529 | struct qstr nm = { .name = name, .len = strlen(name) }; | |
530 | struct ubifs_dent_node *xent; | |
531 | union ubifs_key key; | |
532 | int err; | |
533 | ||
534 | dbg_gen("xattr '%s', ino %lu ('%.*s')", name, | |
535 | host->i_ino, dentry->d_name.len, dentry->d_name.name); | |
536 | ubifs_assert(mutex_is_locked(&host->i_mutex)); | |
537 | ||
538 | err = check_namespace(&nm); | |
539 | if (err < 0) | |
540 | return err; | |
541 | ||
542 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
543 | if (!xent) | |
544 | return -ENOMEM; | |
545 | ||
546 | xent_key_init(c, &key, host->i_ino, &nm); | |
547 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
548 | if (err) { | |
549 | if (err == -ENOENT) | |
550 | err = -ENODATA; | |
551 | goto out_free; | |
552 | } | |
553 | ||
554 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
555 | if (IS_ERR(inode)) { | |
556 | err = PTR_ERR(inode); | |
557 | goto out_free; | |
558 | } | |
559 | ||
560 | ubifs_assert(inode->i_nlink == 1); | |
561 | inode->i_nlink = 0; | |
562 | err = remove_xattr(c, host, inode, &nm); | |
563 | if (err) | |
564 | inode->i_nlink = 1; | |
565 | ||
566 | /* If @i_nlink is 0, 'iput()' will delete the inode */ | |
567 | iput(inode); | |
568 | ||
569 | out_free: | |
570 | kfree(xent); | |
571 | return err; | |
572 | } |