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 | 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, | |
f4f61d2c | 100 | const struct fscrypt_name *nm, const void *value, int size) |
1e51764a | 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 | */ | |
f4f61d2c | 120 | names_len = host_ui->xattr_names + host_ui->xattr_cnt + fname_len(nm) + 1; |
fee1756d | 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 | 141 | |
422edace | 142 | inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME; |
1e51764a AB |
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); | |
607a11ad | 155 | host->i_ctime = current_time(host); |
1e51764a | 156 | host_ui->xattr_cnt += 1; |
f4f61d2c | 157 | host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm)); |
1e51764a | 158 | host_ui->xattr_size += CALC_XATTR_BYTES(size); |
f4f61d2c | 159 | host_ui->xattr_names += fname_len(nm); |
1e51764a | 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 | */ | |
f4f61d2c | 167 | if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0) |
d475a507 RW |
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; | |
2ee6a576 | 173 | ubifs_set_inode_flags(host); |
1e51764a AB |
174 | mutex_unlock(&host_ui->ui_mutex); |
175 | ||
176 | ubifs_release_budget(c, &req); | |
177 | insert_inode_hash(inode); | |
178 | iput(inode); | |
179 | return 0; | |
180 | ||
181 | out_cancel: | |
182 | host_ui->xattr_cnt -= 1; | |
f4f61d2c | 183 | host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm)); |
1e51764a | 184 | host_ui->xattr_size -= CALC_XATTR_BYTES(size); |
f4f61d2c | 185 | host_ui->xattr_names -= fname_len(nm); |
d475a507 | 186 | host_ui->flags &= ~UBIFS_CRYPT_FL; |
1e51764a | 187 | mutex_unlock(&host_ui->ui_mutex); |
c78c7e35 | 188 | out_free: |
1e51764a AB |
189 | make_bad_inode(inode); |
190 | iput(inode); | |
191 | out_budg: | |
192 | ubifs_release_budget(c, &req); | |
193 | return err; | |
194 | } | |
195 | ||
196 | /** | |
197 | * change_xattr - change an extended attribute. | |
198 | * @c: UBIFS file-system description object | |
199 | * @host: host inode | |
200 | * @inode: extended attribute inode | |
201 | * @value: extended attribute value | |
202 | * @size: size of extended attribute value | |
203 | * | |
204 | * This helper function changes the value of extended attribute @inode with new | |
205 | * data from @value. Returns zero in case of success and a negative error code | |
206 | * in case of failure. | |
207 | */ | |
208 | static int change_xattr(struct ubifs_info *c, struct inode *host, | |
209 | struct inode *inode, const void *value, int size) | |
210 | { | |
211 | int err; | |
212 | struct ubifs_inode *host_ui = ubifs_inode(host); | |
213 | struct ubifs_inode *ui = ubifs_inode(inode); | |
ab92a20b | 214 | void *buf = NULL; |
74e9c700 | 215 | int old_size; |
1e51764a | 216 | struct ubifs_budget_req req = { .dirtied_ino = 2, |
5acd6ff8 | 217 | .dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) }; |
1e51764a | 218 | |
6eb61d58 | 219 | ubifs_assert(c, ui->data_len == inode->i_size); |
1e51764a AB |
220 | err = ubifs_budget_space(c, &req); |
221 | if (err) | |
222 | return err; | |
223 | ||
ab92a20b DY |
224 | buf = kmemdup(value, size, GFP_NOFS); |
225 | if (!buf) { | |
1e51764a | 226 | err = -ENOMEM; |
c78c7e35 | 227 | goto out_free; |
1e51764a | 228 | } |
ab92a20b DY |
229 | mutex_lock(&ui->ui_mutex); |
230 | kfree(ui->data); | |
231 | ui->data = buf; | |
1e51764a | 232 | inode->i_size = ui->ui_size = size; |
74e9c700 | 233 | old_size = ui->data_len; |
1e51764a | 234 | ui->data_len = size; |
ab92a20b | 235 | mutex_unlock(&ui->ui_mutex); |
1e51764a | 236 | |
c78c7e35 | 237 | mutex_lock(&host_ui->ui_mutex); |
607a11ad | 238 | host->i_ctime = current_time(host); |
74e9c700 | 239 | host_ui->xattr_size -= CALC_XATTR_BYTES(old_size); |
c78c7e35 AB |
240 | host_ui->xattr_size += CALC_XATTR_BYTES(size); |
241 | ||
1e51764a AB |
242 | /* |
243 | * It is important to write the host inode after the xattr inode | |
244 | * because if the host inode gets synchronized (via 'fsync()'), then | |
245 | * the extended attribute inode gets synchronized, because it goes | |
246 | * before the host inode in the write-buffer. | |
247 | */ | |
248 | err = ubifs_jnl_change_xattr(c, inode, host); | |
249 | if (err) | |
250 | goto out_cancel; | |
251 | mutex_unlock(&host_ui->ui_mutex); | |
252 | ||
253 | ubifs_release_budget(c, &req); | |
254 | return 0; | |
255 | ||
256 | out_cancel: | |
257 | host_ui->xattr_size -= CALC_XATTR_BYTES(size); | |
74e9c700 | 258 | host_ui->xattr_size += CALC_XATTR_BYTES(old_size); |
1e51764a | 259 | mutex_unlock(&host_ui->ui_mutex); |
c78c7e35 AB |
260 | make_bad_inode(inode); |
261 | out_free: | |
1e51764a AB |
262 | ubifs_release_budget(c, &req); |
263 | return err; | |
264 | } | |
265 | ||
1e51764a AB |
266 | static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum) |
267 | { | |
268 | struct inode *inode; | |
269 | ||
270 | inode = ubifs_iget(c->vfs_sb, inum); | |
271 | if (IS_ERR(inode)) { | |
235c362b | 272 | ubifs_err(c, "dead extended attribute entry, error %d", |
1e51764a AB |
273 | (int)PTR_ERR(inode)); |
274 | return inode; | |
275 | } | |
276 | if (ubifs_inode(inode)->xattr) | |
277 | return inode; | |
235c362b | 278 | ubifs_err(c, "corrupt extended attribute entry"); |
1e51764a AB |
279 | iput(inode); |
280 | return ERR_PTR(-EINVAL); | |
281 | } | |
282 | ||
ade46c3a | 283 | int ubifs_xattr_set(struct inode *host, const char *name, const void *value, |
d8db5b1c | 284 | size_t size, int flags, bool check_lock) |
1e51764a | 285 | { |
895d9db2 | 286 | struct inode *inode; |
1e51764a | 287 | struct ubifs_info *c = host->i_sb->s_fs_info; |
f4f61d2c | 288 | struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; |
1e51764a AB |
289 | struct ubifs_dent_node *xent; |
290 | union ubifs_key key; | |
2b88fc21 | 291 | int err; |
1e51764a | 292 | |
d8db5b1c | 293 | if (check_lock) |
6eb61d58 | 294 | ubifs_assert(c, inode_is_locked(host)); |
1e51764a AB |
295 | |
296 | if (size > UBIFS_MAX_INO_DATA) | |
297 | return -ERANGE; | |
298 | ||
f4f61d2c | 299 | if (fname_len(&nm) > UBIFS_MAX_NLEN) |
2b88fc21 | 300 | return -ENAMETOOLONG; |
1e51764a AB |
301 | |
302 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
303 | if (!xent) | |
304 | return -ENOMEM; | |
305 | ||
306 | /* | |
307 | * The extended attribute entries are stored in LNC, so multiple | |
308 | * look-ups do not involve reading the flash. | |
309 | */ | |
310 | xent_key_init(c, &key, host->i_ino, &nm); | |
311 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
312 | if (err) { | |
313 | if (err != -ENOENT) | |
314 | goto out_free; | |
315 | ||
316 | if (flags & XATTR_REPLACE) | |
317 | /* We are asked not to create the xattr */ | |
318 | err = -ENODATA; | |
319 | else | |
320 | err = create_xattr(c, host, &nm, value, size); | |
321 | goto out_free; | |
322 | } | |
323 | ||
324 | if (flags & XATTR_CREATE) { | |
325 | /* We are asked not to replace the xattr */ | |
326 | err = -EEXIST; | |
327 | goto out_free; | |
328 | } | |
329 | ||
330 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
331 | if (IS_ERR(inode)) { | |
332 | err = PTR_ERR(inode); | |
333 | goto out_free; | |
334 | } | |
335 | ||
336 | err = change_xattr(c, host, inode, value, size); | |
337 | iput(inode); | |
338 | ||
339 | out_free: | |
340 | kfree(xent); | |
341 | return err; | |
342 | } | |
343 | ||
ade46c3a RW |
344 | ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf, |
345 | size_t size) | |
1e51764a | 346 | { |
ce23e640 | 347 | struct inode *inode; |
1e51764a | 348 | struct ubifs_info *c = host->i_sb->s_fs_info; |
f4f61d2c | 349 | struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; |
1e51764a AB |
350 | struct ubifs_inode *ui; |
351 | struct ubifs_dent_node *xent; | |
352 | union ubifs_key key; | |
353 | int err; | |
354 | ||
f4f61d2c | 355 | if (fname_len(&nm) > UBIFS_MAX_NLEN) |
2b88fc21 | 356 | return -ENAMETOOLONG; |
1e51764a AB |
357 | |
358 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
359 | if (!xent) | |
360 | return -ENOMEM; | |
361 | ||
1e51764a AB |
362 | xent_key_init(c, &key, host->i_ino, &nm); |
363 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
364 | if (err) { | |
365 | if (err == -ENOENT) | |
366 | err = -ENODATA; | |
367 | goto out_unlock; | |
368 | } | |
369 | ||
370 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
371 | if (IS_ERR(inode)) { | |
372 | err = PTR_ERR(inode); | |
373 | goto out_unlock; | |
374 | } | |
375 | ||
376 | ui = ubifs_inode(inode); | |
6eb61d58 RW |
377 | ubifs_assert(c, inode->i_size == ui->data_len); |
378 | ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len); | |
1e51764a | 379 | |
ab92a20b | 380 | mutex_lock(&ui->ui_mutex); |
1e51764a AB |
381 | if (buf) { |
382 | /* If @buf is %NULL we are supposed to return the length */ | |
383 | if (ui->data_len > size) { | |
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; | |
f4f61d2c | 422 | struct fscrypt_name nm = {0}; |
1e51764a | 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 | ||
f4f61d2c RW |
446 | fname_name(&nm) = xent->name; |
447 | fname_len(&nm) = le16_to_cpu(xent->nlen); | |
1e51764a | 448 | |
43b113fe | 449 | if (xattr_visible(xent->name)) { |
f4f61d2c RW |
450 | memcpy(buffer + written, fname_name(&nm), fname_len(&nm) + 1); |
451 | written += fname_len(&nm) + 1; | |
1e51764a AB |
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 | ||
6eb61d58 | 465 | ubifs_assert(c, written <= size); |
1e51764a AB |
466 | return written; |
467 | } | |
468 | ||
469 | static int remove_xattr(struct ubifs_info *c, struct inode *host, | |
f4f61d2c | 470 | struct inode *inode, const struct fscrypt_name *nm) |
1e51764a AB |
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 | 477 | |
6eb61d58 | 478 | ubifs_assert(c, ui->data_len == inode->i_size); |
1e51764a AB |
479 | |
480 | err = ubifs_budget_space(c, &req); | |
481 | if (err) | |
482 | return err; | |
483 | ||
484 | mutex_lock(&host_ui->ui_mutex); | |
607a11ad | 485 | host->i_ctime = current_time(host); |
1e51764a | 486 | host_ui->xattr_cnt -= 1; |
f4f61d2c | 487 | host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm)); |
1e51764a | 488 | host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len); |
f4f61d2c | 489 | host_ui->xattr_names -= fname_len(nm); |
1e51764a AB |
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; | |
f4f61d2c | 501 | host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm)); |
1e51764a | 502 | host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len); |
f4f61d2c | 503 | host_ui->xattr_names += fname_len(nm); |
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 | ||
272eda82 RW |
510 | /** |
511 | * ubifs_evict_xattr_inode - Evict an xattr inode. | |
512 | * @c: UBIFS file-system description object | |
513 | * @xattr_inum: xattr inode number | |
514 | * | |
515 | * When an inode that hosts xattrs is being removed we have to make sure | |
516 | * that cached inodes of the xattrs also get removed from the inode cache | |
517 | * otherwise we'd waste memory. This function looks up an inode from the | |
518 | * inode cache and clears the link counter such that iput() will evict | |
519 | * the inode. | |
520 | */ | |
521 | void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum) | |
522 | { | |
523 | struct inode *inode; | |
524 | ||
525 | inode = ilookup(c->vfs_sb, xattr_inum); | |
526 | if (inode) { | |
527 | clear_nlink(inode); | |
528 | iput(inode); | |
529 | } | |
530 | } | |
531 | ||
ade46c3a | 532 | static int ubifs_xattr_remove(struct inode *host, const char *name) |
1e51764a | 533 | { |
2b88fc21 | 534 | struct inode *inode; |
1e51764a | 535 | struct ubifs_info *c = host->i_sb->s_fs_info; |
f4f61d2c | 536 | struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; |
1e51764a AB |
537 | struct ubifs_dent_node *xent; |
538 | union ubifs_key key; | |
539 | int err; | |
540 | ||
6eb61d58 | 541 | ubifs_assert(c, inode_is_locked(host)); |
1e51764a | 542 | |
f4f61d2c | 543 | if (fname_len(&nm) > UBIFS_MAX_NLEN) |
2b88fc21 | 544 | return -ENAMETOOLONG; |
1e51764a AB |
545 | |
546 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
547 | if (!xent) | |
548 | return -ENOMEM; | |
549 | ||
550 | xent_key_init(c, &key, host->i_ino, &nm); | |
551 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
552 | if (err) { | |
553 | if (err == -ENOENT) | |
554 | err = -ENODATA; | |
555 | goto out_free; | |
556 | } | |
557 | ||
558 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
559 | if (IS_ERR(inode)) { | |
560 | err = PTR_ERR(inode); | |
561 | goto out_free; | |
562 | } | |
563 | ||
6eb61d58 | 564 | ubifs_assert(c, inode->i_nlink == 1); |
6d6b77f1 | 565 | clear_nlink(inode); |
1e51764a AB |
566 | err = remove_xattr(c, host, inode, &nm); |
567 | if (err) | |
bfe86848 | 568 | set_nlink(inode, 1); |
1e51764a AB |
569 | |
570 | /* If @i_nlink is 0, 'iput()' will delete the inode */ | |
571 | iput(inode); | |
572 | ||
573 | out_free: | |
574 | kfree(xent); | |
575 | return err; | |
576 | } | |
d7f0b70d | 577 | |
8326c1ee | 578 | #ifdef CONFIG_UBIFS_FS_SECURITY |
d7f0b70d SN |
579 | static int init_xattrs(struct inode *inode, const struct xattr *xattr_array, |
580 | void *fs_info) | |
581 | { | |
582 | const struct xattr *xattr; | |
583 | char *name; | |
584 | int err = 0; | |
585 | ||
586 | for (xattr = xattr_array; xattr->name != NULL; xattr++) { | |
587 | name = kmalloc(XATTR_SECURITY_PREFIX_LEN + | |
588 | strlen(xattr->name) + 1, GFP_NOFS); | |
589 | if (!name) { | |
590 | err = -ENOMEM; | |
591 | break; | |
592 | } | |
593 | strcpy(name, XATTR_SECURITY_PREFIX); | |
594 | strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name); | |
d8db5b1c XL |
595 | /* |
596 | * creating a new inode without holding the inode rwsem, | |
597 | * no need to check whether inode is locked. | |
598 | */ | |
ade46c3a | 599 | err = ubifs_xattr_set(inode, name, xattr->value, |
d8db5b1c | 600 | xattr->value_len, 0, false); |
d7f0b70d SN |
601 | kfree(name); |
602 | if (err < 0) | |
603 | break; | |
604 | } | |
605 | ||
606 | return err; | |
607 | } | |
608 | ||
609 | int ubifs_init_security(struct inode *dentry, struct inode *inode, | |
610 | const struct qstr *qstr) | |
611 | { | |
612 | int err; | |
613 | ||
d7f0b70d SN |
614 | err = security_inode_init_security(inode, dentry, qstr, |
615 | &init_xattrs, 0); | |
235c362b SY |
616 | if (err) { |
617 | struct ubifs_info *c = dentry->i_sb->s_fs_info; | |
618 | ubifs_err(c, "cannot initialize security for inode %lu, error %d", | |
fee1756d | 619 | inode->i_ino, err); |
235c362b | 620 | } |
d7f0b70d SN |
621 | return err; |
622 | } | |
8326c1ee | 623 | #endif |
2b88fc21 | 624 | |
ade46c3a | 625 | static int xattr_get(const struct xattr_handler *handler, |
2b88fc21 AG |
626 | struct dentry *dentry, struct inode *inode, |
627 | const char *name, void *buffer, size_t size) | |
628 | { | |
629 | dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name, | |
630 | inode->i_ino, dentry, size); | |
631 | ||
17ce1eb0 | 632 | name = xattr_full_name(handler, name); |
ade46c3a | 633 | return ubifs_xattr_get(inode, name, buffer, size); |
2b88fc21 AG |
634 | } |
635 | ||
ade46c3a | 636 | static int xattr_set(const struct xattr_handler *handler, |
59301226 AV |
637 | struct dentry *dentry, struct inode *inode, |
638 | const char *name, const void *value, | |
639 | size_t size, int flags) | |
2b88fc21 | 640 | { |
2b88fc21 AG |
641 | dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd", |
642 | name, inode->i_ino, dentry, size); | |
643 | ||
17ce1eb0 RW |
644 | name = xattr_full_name(handler, name); |
645 | ||
2b88fc21 | 646 | if (value) |
d8db5b1c | 647 | return ubifs_xattr_set(inode, name, value, size, flags, true); |
2b88fc21 | 648 | else |
ade46c3a | 649 | return ubifs_xattr_remove(inode, name); |
2b88fc21 AG |
650 | } |
651 | ||
dfaf8d2a | 652 | static const struct xattr_handler ubifs_user_xattr_handler = { |
2b88fc21 | 653 | .prefix = XATTR_USER_PREFIX, |
ade46c3a RW |
654 | .get = xattr_get, |
655 | .set = xattr_set, | |
2b88fc21 AG |
656 | }; |
657 | ||
dfaf8d2a | 658 | static const struct xattr_handler ubifs_trusted_xattr_handler = { |
2b88fc21 | 659 | .prefix = XATTR_TRUSTED_PREFIX, |
ade46c3a RW |
660 | .get = xattr_get, |
661 | .set = xattr_set, | |
2b88fc21 AG |
662 | }; |
663 | ||
8326c1ee | 664 | #ifdef CONFIG_UBIFS_FS_SECURITY |
dfaf8d2a | 665 | static const struct xattr_handler ubifs_security_xattr_handler = { |
2b88fc21 | 666 | .prefix = XATTR_SECURITY_PREFIX, |
ade46c3a RW |
667 | .get = xattr_get, |
668 | .set = xattr_set, | |
2b88fc21 | 669 | }; |
8326c1ee | 670 | #endif |
2b88fc21 AG |
671 | |
672 | const struct xattr_handler *ubifs_xattr_handlers[] = { | |
673 | &ubifs_user_xattr_handler, | |
674 | &ubifs_trusted_xattr_handler, | |
8326c1ee | 675 | #ifdef CONFIG_UBIFS_FS_SECURITY |
2b88fc21 | 676 | &ubifs_security_xattr_handler, |
8326c1ee | 677 | #endif |
2b88fc21 AG |
678 | NULL |
679 | }; |