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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 | 61 | #include <linux/xattr.h> |
1e51764a AB |
62 | |
63 | /* | |
64 | * Limit the number of extended attributes per inode so that the total size | |
c78c7e35 | 65 | * (@xattr_size) is guaranteeded to fit in an 'unsigned int'. |
1e51764a AB |
66 | */ |
67 | #define MAX_XATTRS_PER_INODE 65535 | |
68 | ||
69 | /* | |
70 | * Extended attribute type constants. | |
71 | * | |
72 | * USER_XATTR: user extended attribute ("user.*") | |
73 | * TRUSTED_XATTR: trusted extended attribute ("trusted.*) | |
74 | * SECURITY_XATTR: security extended attribute ("security.*") | |
75 | */ | |
76 | enum { | |
77 | USER_XATTR, | |
78 | TRUSTED_XATTR, | |
79 | SECURITY_XATTR, | |
80 | }; | |
81 | ||
14ffd5d0 SD |
82 | static const struct inode_operations empty_iops; |
83 | static const struct file_operations empty_fops; | |
1e51764a AB |
84 | |
85 | /** | |
86 | * create_xattr - create an extended attribute. | |
87 | * @c: UBIFS file-system description object | |
88 | * @host: host inode | |
89 | * @nm: extended attribute name | |
90 | * @value: extended attribute value | |
91 | * @size: size of extended attribute value | |
92 | * | |
93 | * This is a helper function which creates an extended attribute of name @nm | |
94 | * and value @value for inode @host. The host inode is also updated on flash | |
95 | * because the ctime and extended attribute accounting data changes. This | |
96 | * function returns zero in case of success and a negative error code in case | |
97 | * of failure. | |
98 | */ | |
99 | static int create_xattr(struct ubifs_info *c, struct inode *host, | |
100 | const struct qstr *nm, const void *value, int size) | |
101 | { | |
fee1756d | 102 | int err, names_len; |
1e51764a AB |
103 | struct inode *inode; |
104 | struct ubifs_inode *ui, *host_ui = ubifs_inode(host); | |
105 | struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1, | |
5acd6ff8 ZS |
106 | .new_ino_d = ALIGN(size, 8), .dirtied_ino = 1, |
107 | .dirtied_ino_d = ALIGN(host_ui->data_len, 8) }; | |
1e51764a | 108 | |
fee1756d | 109 | if (host_ui->xattr_cnt >= MAX_XATTRS_PER_INODE) { |
235c362b | 110 | ubifs_err(c, "inode %lu already has too many xattrs (%d), cannot create more", |
fee1756d | 111 | host->i_ino, host_ui->xattr_cnt); |
1e51764a | 112 | return -ENOSPC; |
fee1756d | 113 | } |
1e51764a AB |
114 | /* |
115 | * Linux limits the maximum size of the extended attribute names list | |
c78c7e35 | 116 | * to %XATTR_LIST_MAX. This means we should not allow creating more |
1e51764a AB |
117 | * extended attributes if the name list becomes larger. This limitation |
118 | * is artificial for UBIFS, though. | |
119 | */ | |
fee1756d SN |
120 | names_len = host_ui->xattr_names + host_ui->xattr_cnt + nm->len + 1; |
121 | if (names_len > XATTR_LIST_MAX) { | |
235c362b | 122 | ubifs_err(c, "cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d", |
fee1756d | 123 | host->i_ino, names_len, XATTR_LIST_MAX); |
1e51764a | 124 | return -ENOSPC; |
fee1756d | 125 | } |
1e51764a AB |
126 | |
127 | err = ubifs_budget_space(c, &req); | |
128 | if (err) | |
129 | return err; | |
130 | ||
131 | inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO); | |
132 | if (IS_ERR(inode)) { | |
133 | err = PTR_ERR(inode); | |
134 | goto out_budg; | |
135 | } | |
136 | ||
1e51764a | 137 | /* Re-define all operations to be "nothing" */ |
7dcda1c9 | 138 | inode->i_mapping->a_ops = &empty_aops; |
14ffd5d0 SD |
139 | inode->i_op = &empty_iops; |
140 | inode->i_fop = &empty_fops; | |
1e51764a AB |
141 | |
142 | inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME | S_NOQUOTA; | |
143 | ui = ubifs_inode(inode); | |
144 | ui->xattr = 1; | |
145 | ui->flags |= UBIFS_XATTR_FL; | |
eaecf43a | 146 | ui->data = kmemdup(value, size, GFP_NOFS); |
1e51764a AB |
147 | if (!ui->data) { |
148 | err = -ENOMEM; | |
c78c7e35 | 149 | goto out_free; |
1e51764a | 150 | } |
c78c7e35 AB |
151 | inode->i_size = ui->ui_size = size; |
152 | ui->data_len = size; | |
153 | ||
154 | mutex_lock(&host_ui->ui_mutex); | |
1e51764a AB |
155 | host->i_ctime = ubifs_current_time(host); |
156 | host_ui->xattr_cnt += 1; | |
157 | host_ui->xattr_size += CALC_DENT_SIZE(nm->len); | |
158 | host_ui->xattr_size += CALC_XATTR_BYTES(size); | |
159 | host_ui->xattr_names += nm->len; | |
160 | ||
d475a507 RW |
161 | /* |
162 | * We handle UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT here because we | |
163 | * have to set the UBIFS_CRYPT_FL flag on the host inode. | |
164 | * To avoid multiple updates of the same inode in the same operation, | |
165 | * let's do it here. | |
166 | */ | |
167 | if (strcmp(nm->name, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0) | |
168 | host_ui->flags |= UBIFS_CRYPT_FL; | |
169 | ||
1e51764a AB |
170 | err = ubifs_jnl_update(c, host, nm, inode, 0, 1); |
171 | if (err) | |
172 | goto out_cancel; | |
173 | mutex_unlock(&host_ui->ui_mutex); | |
174 | ||
175 | ubifs_release_budget(c, &req); | |
176 | insert_inode_hash(inode); | |
177 | iput(inode); | |
178 | return 0; | |
179 | ||
180 | out_cancel: | |
181 | host_ui->xattr_cnt -= 1; | |
182 | host_ui->xattr_size -= CALC_DENT_SIZE(nm->len); | |
183 | host_ui->xattr_size -= CALC_XATTR_BYTES(size); | |
843741c5 | 184 | host_ui->xattr_names -= nm->len; |
d475a507 | 185 | host_ui->flags &= ~UBIFS_CRYPT_FL; |
1e51764a | 186 | mutex_unlock(&host_ui->ui_mutex); |
c78c7e35 | 187 | out_free: |
1e51764a AB |
188 | make_bad_inode(inode); |
189 | iput(inode); | |
190 | out_budg: | |
191 | ubifs_release_budget(c, &req); | |
192 | return err; | |
193 | } | |
194 | ||
195 | /** | |
196 | * change_xattr - change an extended attribute. | |
197 | * @c: UBIFS file-system description object | |
198 | * @host: host inode | |
199 | * @inode: extended attribute inode | |
200 | * @value: extended attribute value | |
201 | * @size: size of extended attribute value | |
202 | * | |
203 | * This helper function changes the value of extended attribute @inode with new | |
204 | * data from @value. Returns zero in case of success and a negative error code | |
205 | * in case of failure. | |
206 | */ | |
207 | static int change_xattr(struct ubifs_info *c, struct inode *host, | |
208 | struct inode *inode, const void *value, int size) | |
209 | { | |
210 | int err; | |
211 | struct ubifs_inode *host_ui = ubifs_inode(host); | |
212 | struct ubifs_inode *ui = ubifs_inode(inode); | |
ab92a20b | 213 | void *buf = NULL; |
74e9c700 | 214 | int old_size; |
1e51764a | 215 | struct ubifs_budget_req req = { .dirtied_ino = 2, |
5acd6ff8 | 216 | .dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) }; |
1e51764a AB |
217 | |
218 | ubifs_assert(ui->data_len == inode->i_size); | |
219 | err = ubifs_budget_space(c, &req); | |
220 | if (err) | |
221 | return err; | |
222 | ||
ab92a20b DY |
223 | buf = kmemdup(value, size, GFP_NOFS); |
224 | if (!buf) { | |
1e51764a | 225 | err = -ENOMEM; |
c78c7e35 | 226 | goto out_free; |
1e51764a | 227 | } |
ab92a20b DY |
228 | mutex_lock(&ui->ui_mutex); |
229 | kfree(ui->data); | |
230 | ui->data = buf; | |
1e51764a | 231 | inode->i_size = ui->ui_size = size; |
74e9c700 | 232 | old_size = ui->data_len; |
1e51764a | 233 | ui->data_len = size; |
ab92a20b | 234 | mutex_unlock(&ui->ui_mutex); |
1e51764a | 235 | |
c78c7e35 AB |
236 | mutex_lock(&host_ui->ui_mutex); |
237 | host->i_ctime = ubifs_current_time(host); | |
74e9c700 | 238 | host_ui->xattr_size -= CALC_XATTR_BYTES(old_size); |
c78c7e35 AB |
239 | host_ui->xattr_size += CALC_XATTR_BYTES(size); |
240 | ||
1e51764a AB |
241 | /* |
242 | * It is important to write the host inode after the xattr inode | |
243 | * because if the host inode gets synchronized (via 'fsync()'), then | |
244 | * the extended attribute inode gets synchronized, because it goes | |
245 | * before the host inode in the write-buffer. | |
246 | */ | |
247 | err = ubifs_jnl_change_xattr(c, inode, host); | |
248 | if (err) | |
249 | goto out_cancel; | |
250 | mutex_unlock(&host_ui->ui_mutex); | |
251 | ||
252 | ubifs_release_budget(c, &req); | |
253 | return 0; | |
254 | ||
255 | out_cancel: | |
256 | host_ui->xattr_size -= CALC_XATTR_BYTES(size); | |
74e9c700 | 257 | host_ui->xattr_size += CALC_XATTR_BYTES(old_size); |
1e51764a | 258 | mutex_unlock(&host_ui->ui_mutex); |
c78c7e35 AB |
259 | make_bad_inode(inode); |
260 | out_free: | |
1e51764a AB |
261 | ubifs_release_budget(c, &req); |
262 | return err; | |
263 | } | |
264 | ||
1e51764a AB |
265 | static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum) |
266 | { | |
267 | struct inode *inode; | |
268 | ||
269 | inode = ubifs_iget(c->vfs_sb, inum); | |
270 | if (IS_ERR(inode)) { | |
235c362b | 271 | ubifs_err(c, "dead extended attribute entry, error %d", |
1e51764a AB |
272 | (int)PTR_ERR(inode)); |
273 | return inode; | |
274 | } | |
275 | if (ubifs_inode(inode)->xattr) | |
276 | return inode; | |
235c362b | 277 | ubifs_err(c, "corrupt extended attribute entry"); |
1e51764a AB |
278 | iput(inode); |
279 | return ERR_PTR(-EINVAL); | |
280 | } | |
281 | ||
ade46c3a RW |
282 | int ubifs_xattr_set(struct inode *host, const char *name, const void *value, |
283 | size_t size, int flags) | |
1e51764a | 284 | { |
895d9db2 | 285 | struct inode *inode; |
1e51764a | 286 | struct ubifs_info *c = host->i_sb->s_fs_info; |
26fe5750 | 287 | struct qstr nm = QSTR_INIT(name, strlen(name)); |
1e51764a AB |
288 | struct ubifs_dent_node *xent; |
289 | union ubifs_key key; | |
2b88fc21 | 290 | int err; |
1e51764a | 291 | |
5955102c | 292 | ubifs_assert(inode_is_locked(host)); |
1e51764a AB |
293 | |
294 | if (size > UBIFS_MAX_INO_DATA) | |
295 | return -ERANGE; | |
296 | ||
2b88fc21 AG |
297 | if (nm.len > UBIFS_MAX_NLEN) |
298 | return -ENAMETOOLONG; | |
1e51764a AB |
299 | |
300 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
301 | if (!xent) | |
302 | return -ENOMEM; | |
303 | ||
304 | /* | |
305 | * The extended attribute entries are stored in LNC, so multiple | |
306 | * look-ups do not involve reading the flash. | |
307 | */ | |
308 | xent_key_init(c, &key, host->i_ino, &nm); | |
309 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
310 | if (err) { | |
311 | if (err != -ENOENT) | |
312 | goto out_free; | |
313 | ||
314 | if (flags & XATTR_REPLACE) | |
315 | /* We are asked not to create the xattr */ | |
316 | err = -ENODATA; | |
317 | else | |
318 | err = create_xattr(c, host, &nm, value, size); | |
319 | goto out_free; | |
320 | } | |
321 | ||
322 | if (flags & XATTR_CREATE) { | |
323 | /* We are asked not to replace the xattr */ | |
324 | err = -EEXIST; | |
325 | goto out_free; | |
326 | } | |
327 | ||
328 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
329 | if (IS_ERR(inode)) { | |
330 | err = PTR_ERR(inode); | |
331 | goto out_free; | |
332 | } | |
333 | ||
334 | err = change_xattr(c, host, inode, value, size); | |
335 | iput(inode); | |
336 | ||
337 | out_free: | |
338 | kfree(xent); | |
339 | return err; | |
340 | } | |
341 | ||
ade46c3a RW |
342 | ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf, |
343 | size_t size) | |
1e51764a | 344 | { |
ce23e640 | 345 | struct inode *inode; |
1e51764a | 346 | struct ubifs_info *c = host->i_sb->s_fs_info; |
26fe5750 | 347 | struct qstr nm = QSTR_INIT(name, strlen(name)); |
1e51764a AB |
348 | struct ubifs_inode *ui; |
349 | struct ubifs_dent_node *xent; | |
350 | union ubifs_key key; | |
351 | int err; | |
352 | ||
2b88fc21 AG |
353 | if (nm.len > UBIFS_MAX_NLEN) |
354 | return -ENAMETOOLONG; | |
1e51764a AB |
355 | |
356 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
357 | if (!xent) | |
358 | return -ENOMEM; | |
359 | ||
1e51764a AB |
360 | xent_key_init(c, &key, host->i_ino, &nm); |
361 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
362 | if (err) { | |
363 | if (err == -ENOENT) | |
364 | err = -ENODATA; | |
365 | goto out_unlock; | |
366 | } | |
367 | ||
368 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
369 | if (IS_ERR(inode)) { | |
370 | err = PTR_ERR(inode); | |
371 | goto out_unlock; | |
372 | } | |
373 | ||
374 | ui = ubifs_inode(inode); | |
375 | ubifs_assert(inode->i_size == ui->data_len); | |
376 | ubifs_assert(ubifs_inode(host)->xattr_size > ui->data_len); | |
377 | ||
ab92a20b | 378 | mutex_lock(&ui->ui_mutex); |
1e51764a AB |
379 | if (buf) { |
380 | /* If @buf is %NULL we are supposed to return the length */ | |
381 | if (ui->data_len > size) { | |
235c362b | 382 | ubifs_err(c, "buffer size %zd, xattr len %d", |
a6aae4dd | 383 | size, ui->data_len); |
1e51764a AB |
384 | err = -ERANGE; |
385 | goto out_iput; | |
386 | } | |
387 | ||
388 | memcpy(buf, ui->data, ui->data_len); | |
389 | } | |
390 | err = ui->data_len; | |
391 | ||
392 | out_iput: | |
ab92a20b | 393 | mutex_unlock(&ui->ui_mutex); |
1e51764a AB |
394 | iput(inode); |
395 | out_unlock: | |
1e51764a AB |
396 | kfree(xent); |
397 | return err; | |
398 | } | |
399 | ||
43b113fe RW |
400 | static bool xattr_visible(const char *name) |
401 | { | |
402 | /* File encryption related xattrs are for internal use only */ | |
403 | if (strcmp(name, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0) | |
404 | return false; | |
405 | ||
406 | /* Show trusted namespace only for "power" users */ | |
407 | if (strncmp(name, XATTR_TRUSTED_PREFIX, | |
408 | XATTR_TRUSTED_PREFIX_LEN) == 0 && !capable(CAP_SYS_ADMIN)) | |
409 | return false; | |
410 | ||
411 | return true; | |
412 | } | |
413 | ||
1e51764a AB |
414 | ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size) |
415 | { | |
416 | union ubifs_key key; | |
2b0143b5 | 417 | struct inode *host = d_inode(dentry); |
1e51764a AB |
418 | struct ubifs_info *c = host->i_sb->s_fs_info; |
419 | struct ubifs_inode *host_ui = ubifs_inode(host); | |
420 | struct ubifs_dent_node *xent, *pxent = NULL; | |
421 | int err, len, written = 0; | |
422 | struct qstr nm = { .name = NULL }; | |
423 | ||
4cb2a01d AV |
424 | dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino, |
425 | dentry, size); | |
1e51764a AB |
426 | |
427 | len = host_ui->xattr_names + host_ui->xattr_cnt; | |
428 | if (!buffer) | |
429 | /* | |
430 | * We should return the minimum buffer size which will fit a | |
431 | * null-terminated list of all the extended attribute names. | |
432 | */ | |
433 | return len; | |
434 | ||
435 | if (len > size) | |
436 | return -ERANGE; | |
437 | ||
438 | lowest_xent_key(c, &key, host->i_ino); | |
1e51764a | 439 | while (1) { |
1e51764a | 440 | xent = ubifs_tnc_next_ent(c, &key, &nm); |
8d47aef4 | 441 | if (IS_ERR(xent)) { |
1e51764a AB |
442 | err = PTR_ERR(xent); |
443 | break; | |
444 | } | |
445 | ||
446 | nm.name = xent->name; | |
447 | nm.len = le16_to_cpu(xent->nlen); | |
448 | ||
43b113fe | 449 | if (xattr_visible(xent->name)) { |
1e51764a AB |
450 | memcpy(buffer + written, nm.name, nm.len + 1); |
451 | written += nm.len + 1; | |
452 | } | |
453 | ||
454 | kfree(pxent); | |
455 | pxent = xent; | |
456 | key_read(c, &xent->key, &key); | |
457 | } | |
1e51764a AB |
458 | |
459 | kfree(pxent); | |
460 | if (err != -ENOENT) { | |
235c362b | 461 | ubifs_err(c, "cannot find next direntry, error %d", err); |
1e51764a AB |
462 | return err; |
463 | } | |
464 | ||
465 | ubifs_assert(written <= size); | |
466 | return written; | |
467 | } | |
468 | ||
469 | static int remove_xattr(struct ubifs_info *c, struct inode *host, | |
470 | struct inode *inode, const struct qstr *nm) | |
471 | { | |
472 | int err; | |
473 | struct ubifs_inode *host_ui = ubifs_inode(host); | |
474 | struct ubifs_inode *ui = ubifs_inode(inode); | |
5acd6ff8 ZS |
475 | struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1, |
476 | .dirtied_ino_d = ALIGN(host_ui->data_len, 8) }; | |
1e51764a AB |
477 | |
478 | ubifs_assert(ui->data_len == inode->i_size); | |
479 | ||
480 | err = ubifs_budget_space(c, &req); | |
481 | if (err) | |
482 | return err; | |
483 | ||
484 | mutex_lock(&host_ui->ui_mutex); | |
485 | host->i_ctime = ubifs_current_time(host); | |
486 | host_ui->xattr_cnt -= 1; | |
487 | host_ui->xattr_size -= CALC_DENT_SIZE(nm->len); | |
488 | host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len); | |
489 | host_ui->xattr_names -= nm->len; | |
490 | ||
491 | err = ubifs_jnl_delete_xattr(c, host, inode, nm); | |
492 | if (err) | |
493 | goto out_cancel; | |
494 | mutex_unlock(&host_ui->ui_mutex); | |
495 | ||
496 | ubifs_release_budget(c, &req); | |
497 | return 0; | |
498 | ||
499 | out_cancel: | |
500 | host_ui->xattr_cnt += 1; | |
501 | host_ui->xattr_size += CALC_DENT_SIZE(nm->len); | |
502 | host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len); | |
843741c5 | 503 | host_ui->xattr_names += nm->len; |
1e51764a AB |
504 | mutex_unlock(&host_ui->ui_mutex); |
505 | ubifs_release_budget(c, &req); | |
506 | make_bad_inode(inode); | |
507 | return err; | |
508 | } | |
509 | ||
ade46c3a | 510 | static int ubifs_xattr_remove(struct inode *host, const char *name) |
1e51764a | 511 | { |
2b88fc21 | 512 | struct inode *inode; |
1e51764a | 513 | struct ubifs_info *c = host->i_sb->s_fs_info; |
26fe5750 | 514 | struct qstr nm = QSTR_INIT(name, strlen(name)); |
1e51764a AB |
515 | struct ubifs_dent_node *xent; |
516 | union ubifs_key key; | |
517 | int err; | |
518 | ||
5955102c | 519 | ubifs_assert(inode_is_locked(host)); |
1e51764a | 520 | |
2b88fc21 AG |
521 | if (nm.len > UBIFS_MAX_NLEN) |
522 | return -ENAMETOOLONG; | |
1e51764a AB |
523 | |
524 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
525 | if (!xent) | |
526 | return -ENOMEM; | |
527 | ||
528 | xent_key_init(c, &key, host->i_ino, &nm); | |
529 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
530 | if (err) { | |
531 | if (err == -ENOENT) | |
532 | err = -ENODATA; | |
533 | goto out_free; | |
534 | } | |
535 | ||
536 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
537 | if (IS_ERR(inode)) { | |
538 | err = PTR_ERR(inode); | |
539 | goto out_free; | |
540 | } | |
541 | ||
542 | ubifs_assert(inode->i_nlink == 1); | |
6d6b77f1 | 543 | clear_nlink(inode); |
1e51764a AB |
544 | err = remove_xattr(c, host, inode, &nm); |
545 | if (err) | |
bfe86848 | 546 | set_nlink(inode, 1); |
1e51764a AB |
547 | |
548 | /* If @i_nlink is 0, 'iput()' will delete the inode */ | |
549 | iput(inode); | |
550 | ||
551 | out_free: | |
552 | kfree(xent); | |
553 | return err; | |
554 | } | |
d7f0b70d | 555 | |
d7f0b70d SN |
556 | static int init_xattrs(struct inode *inode, const struct xattr *xattr_array, |
557 | void *fs_info) | |
558 | { | |
559 | const struct xattr *xattr; | |
560 | char *name; | |
561 | int err = 0; | |
562 | ||
563 | for (xattr = xattr_array; xattr->name != NULL; xattr++) { | |
564 | name = kmalloc(XATTR_SECURITY_PREFIX_LEN + | |
565 | strlen(xattr->name) + 1, GFP_NOFS); | |
566 | if (!name) { | |
567 | err = -ENOMEM; | |
568 | break; | |
569 | } | |
570 | strcpy(name, XATTR_SECURITY_PREFIX); | |
571 | strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name); | |
ade46c3a RW |
572 | err = ubifs_xattr_set(inode, name, xattr->value, |
573 | xattr->value_len, 0); | |
d7f0b70d SN |
574 | kfree(name); |
575 | if (err < 0) | |
576 | break; | |
577 | } | |
578 | ||
579 | return err; | |
580 | } | |
581 | ||
582 | int ubifs_init_security(struct inode *dentry, struct inode *inode, | |
583 | const struct qstr *qstr) | |
584 | { | |
585 | int err; | |
586 | ||
d7f0b70d SN |
587 | err = security_inode_init_security(inode, dentry, qstr, |
588 | &init_xattrs, 0); | |
235c362b SY |
589 | if (err) { |
590 | struct ubifs_info *c = dentry->i_sb->s_fs_info; | |
591 | ubifs_err(c, "cannot initialize security for inode %lu, error %d", | |
fee1756d | 592 | inode->i_ino, err); |
235c362b | 593 | } |
d7f0b70d SN |
594 | return err; |
595 | } | |
2b88fc21 | 596 | |
ade46c3a | 597 | static int xattr_get(const struct xattr_handler *handler, |
2b88fc21 AG |
598 | struct dentry *dentry, struct inode *inode, |
599 | const char *name, void *buffer, size_t size) | |
600 | { | |
601 | dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name, | |
602 | inode->i_ino, dentry, size); | |
603 | ||
17ce1eb0 | 604 | name = xattr_full_name(handler, name); |
ade46c3a | 605 | return ubifs_xattr_get(inode, name, buffer, size); |
2b88fc21 AG |
606 | } |
607 | ||
ade46c3a | 608 | static int xattr_set(const struct xattr_handler *handler, |
59301226 AV |
609 | struct dentry *dentry, struct inode *inode, |
610 | const char *name, const void *value, | |
611 | size_t size, int flags) | |
2b88fc21 | 612 | { |
2b88fc21 AG |
613 | dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd", |
614 | name, inode->i_ino, dentry, size); | |
615 | ||
17ce1eb0 RW |
616 | name = xattr_full_name(handler, name); |
617 | ||
2b88fc21 | 618 | if (value) |
ade46c3a | 619 | return ubifs_xattr_set(inode, name, value, size, flags); |
2b88fc21 | 620 | else |
ade46c3a | 621 | return ubifs_xattr_remove(inode, name); |
2b88fc21 AG |
622 | } |
623 | ||
dfaf8d2a | 624 | static const struct xattr_handler ubifs_user_xattr_handler = { |
2b88fc21 | 625 | .prefix = XATTR_USER_PREFIX, |
ade46c3a RW |
626 | .get = xattr_get, |
627 | .set = xattr_set, | |
2b88fc21 AG |
628 | }; |
629 | ||
dfaf8d2a | 630 | static const struct xattr_handler ubifs_trusted_xattr_handler = { |
2b88fc21 | 631 | .prefix = XATTR_TRUSTED_PREFIX, |
ade46c3a RW |
632 | .get = xattr_get, |
633 | .set = xattr_set, | |
2b88fc21 AG |
634 | }; |
635 | ||
dfaf8d2a | 636 | static const struct xattr_handler ubifs_security_xattr_handler = { |
2b88fc21 | 637 | .prefix = XATTR_SECURITY_PREFIX, |
ade46c3a RW |
638 | .get = xattr_get, |
639 | .set = xattr_set, | |
2b88fc21 AG |
640 | }; |
641 | ||
642 | const struct xattr_handler *ubifs_xattr_handlers[] = { | |
643 | &ubifs_user_xattr_handler, | |
644 | &ubifs_trusted_xattr_handler, | |
645 | &ubifs_security_xattr_handler, | |
646 | NULL | |
647 | }; |