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2b27bdcc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1e51764a AB |
2 | /* |
3 | * This file is part of UBIFS. | |
4 | * | |
5 | * Copyright (C) 2006-2008 Nokia Corporation. | |
6 | * | |
1e51764a AB |
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 | ||
073aaa1b | 46 | #include "ubifs.h" |
7dcda1c9 | 47 | #include <linux/fs.h> |
5a0e3ad6 | 48 | #include <linux/slab.h> |
1e51764a | 49 | #include <linux/xattr.h> |
1e51764a | 50 | |
1e51764a AB |
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 | ||
14ffd5d0 SD |
64 | static const struct inode_operations empty_iops; |
65 | static const struct file_operations empty_fops; | |
1e51764a AB |
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, | |
f4f61d2c | 82 | const struct fscrypt_name *nm, const void *value, int size) |
1e51764a | 83 | { |
fee1756d | 84 | int err, names_len; |
1e51764a AB |
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, | |
5acd6ff8 ZS |
88 | .new_ino_d = ALIGN(size, 8), .dirtied_ino = 1, |
89 | .dirtied_ino_d = ALIGN(host_ui->data_len, 8) }; | |
1e51764a | 90 | |
9ca2d732 | 91 | if (host_ui->xattr_cnt >= ubifs_xattr_max_cnt(c)) { |
235c362b | 92 | ubifs_err(c, "inode %lu already has too many xattrs (%d), cannot create more", |
fee1756d | 93 | host->i_ino, host_ui->xattr_cnt); |
1e51764a | 94 | return -ENOSPC; |
fee1756d | 95 | } |
1e51764a AB |
96 | /* |
97 | * Linux limits the maximum size of the extended attribute names list | |
c78c7e35 | 98 | * to %XATTR_LIST_MAX. This means we should not allow creating more |
1e51764a AB |
99 | * extended attributes if the name list becomes larger. This limitation |
100 | * is artificial for UBIFS, though. | |
101 | */ | |
f4f61d2c | 102 | names_len = host_ui->xattr_names + host_ui->xattr_cnt + fname_len(nm) + 1; |
fee1756d | 103 | if (names_len > XATTR_LIST_MAX) { |
235c362b | 104 | ubifs_err(c, "cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d", |
fee1756d | 105 | host->i_ino, names_len, XATTR_LIST_MAX); |
1e51764a | 106 | return -ENOSPC; |
fee1756d | 107 | } |
1e51764a AB |
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 | ||
1e51764a | 119 | /* Re-define all operations to be "nothing" */ |
7dcda1c9 | 120 | inode->i_mapping->a_ops = &empty_aops; |
14ffd5d0 SD |
121 | inode->i_op = &empty_iops; |
122 | inode->i_fop = &empty_fops; | |
1e51764a | 123 | |
422edace | 124 | inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME; |
1e51764a AB |
125 | ui = ubifs_inode(inode); |
126 | ui->xattr = 1; | |
127 | ui->flags |= UBIFS_XATTR_FL; | |
eaecf43a | 128 | ui->data = kmemdup(value, size, GFP_NOFS); |
1e51764a AB |
129 | if (!ui->data) { |
130 | err = -ENOMEM; | |
c78c7e35 | 131 | goto out_free; |
1e51764a | 132 | } |
c78c7e35 AB |
133 | inode->i_size = ui->ui_size = size; |
134 | ui->data_len = size; | |
135 | ||
136 | mutex_lock(&host_ui->ui_mutex); | |
607a11ad | 137 | host->i_ctime = current_time(host); |
1e51764a | 138 | host_ui->xattr_cnt += 1; |
f4f61d2c | 139 | host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm)); |
1e51764a | 140 | host_ui->xattr_size += CALC_XATTR_BYTES(size); |
f4f61d2c | 141 | host_ui->xattr_names += fname_len(nm); |
1e51764a | 142 | |
d475a507 RW |
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 | */ | |
f4f61d2c | 149 | if (strcmp(fname_name(nm), UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT) == 0) |
d475a507 RW |
150 | host_ui->flags |= UBIFS_CRYPT_FL; |
151 | ||
1e51764a AB |
152 | err = ubifs_jnl_update(c, host, nm, inode, 0, 1); |
153 | if (err) | |
154 | goto out_cancel; | |
2ee6a576 | 155 | ubifs_set_inode_flags(host); |
1e51764a AB |
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; | |
f4f61d2c | 165 | host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm)); |
1e51764a | 166 | host_ui->xattr_size -= CALC_XATTR_BYTES(size); |
f4f61d2c | 167 | host_ui->xattr_names -= fname_len(nm); |
d475a507 | 168 | host_ui->flags &= ~UBIFS_CRYPT_FL; |
1e51764a | 169 | mutex_unlock(&host_ui->ui_mutex); |
c78c7e35 | 170 | out_free: |
1e51764a AB |
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); | |
ab92a20b | 196 | void *buf = NULL; |
74e9c700 | 197 | int old_size; |
1e51764a | 198 | struct ubifs_budget_req req = { .dirtied_ino = 2, |
5acd6ff8 | 199 | .dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) }; |
1e51764a | 200 | |
6eb61d58 | 201 | ubifs_assert(c, ui->data_len == inode->i_size); |
1e51764a AB |
202 | err = ubifs_budget_space(c, &req); |
203 | if (err) | |
204 | return err; | |
205 | ||
ab92a20b DY |
206 | buf = kmemdup(value, size, GFP_NOFS); |
207 | if (!buf) { | |
1e51764a | 208 | err = -ENOMEM; |
c78c7e35 | 209 | goto out_free; |
1e51764a | 210 | } |
ab92a20b DY |
211 | mutex_lock(&ui->ui_mutex); |
212 | kfree(ui->data); | |
213 | ui->data = buf; | |
1e51764a | 214 | inode->i_size = ui->ui_size = size; |
74e9c700 | 215 | old_size = ui->data_len; |
1e51764a | 216 | ui->data_len = size; |
ab92a20b | 217 | mutex_unlock(&ui->ui_mutex); |
1e51764a | 218 | |
c78c7e35 | 219 | mutex_lock(&host_ui->ui_mutex); |
607a11ad | 220 | host->i_ctime = current_time(host); |
74e9c700 | 221 | host_ui->xattr_size -= CALC_XATTR_BYTES(old_size); |
c78c7e35 AB |
222 | host_ui->xattr_size += CALC_XATTR_BYTES(size); |
223 | ||
1e51764a AB |
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); | |
74e9c700 | 240 | host_ui->xattr_size += CALC_XATTR_BYTES(old_size); |
1e51764a | 241 | mutex_unlock(&host_ui->ui_mutex); |
c78c7e35 AB |
242 | make_bad_inode(inode); |
243 | out_free: | |
1e51764a AB |
244 | ubifs_release_budget(c, &req); |
245 | return err; | |
246 | } | |
247 | ||
1e51764a AB |
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)) { | |
235c362b | 254 | ubifs_err(c, "dead extended attribute entry, error %d", |
1e51764a AB |
255 | (int)PTR_ERR(inode)); |
256 | return inode; | |
257 | } | |
258 | if (ubifs_inode(inode)->xattr) | |
259 | return inode; | |
235c362b | 260 | ubifs_err(c, "corrupt extended attribute entry"); |
1e51764a AB |
261 | iput(inode); |
262 | return ERR_PTR(-EINVAL); | |
263 | } | |
264 | ||
ade46c3a | 265 | int ubifs_xattr_set(struct inode *host, const char *name, const void *value, |
d8db5b1c | 266 | size_t size, int flags, bool check_lock) |
1e51764a | 267 | { |
895d9db2 | 268 | struct inode *inode; |
1e51764a | 269 | struct ubifs_info *c = host->i_sb->s_fs_info; |
f4f61d2c | 270 | struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; |
1e51764a AB |
271 | struct ubifs_dent_node *xent; |
272 | union ubifs_key key; | |
2b88fc21 | 273 | int err; |
1e51764a | 274 | |
d8db5b1c | 275 | if (check_lock) |
6eb61d58 | 276 | ubifs_assert(c, inode_is_locked(host)); |
1e51764a AB |
277 | |
278 | if (size > UBIFS_MAX_INO_DATA) | |
279 | return -ERANGE; | |
280 | ||
f4f61d2c | 281 | if (fname_len(&nm) > UBIFS_MAX_NLEN) |
2b88fc21 | 282 | return -ENAMETOOLONG; |
1e51764a AB |
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 | ||
ade46c3a RW |
326 | ssize_t ubifs_xattr_get(struct inode *host, const char *name, void *buf, |
327 | size_t size) | |
1e51764a | 328 | { |
ce23e640 | 329 | struct inode *inode; |
1e51764a | 330 | struct ubifs_info *c = host->i_sb->s_fs_info; |
f4f61d2c | 331 | struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; |
1e51764a AB |
332 | struct ubifs_inode *ui; |
333 | struct ubifs_dent_node *xent; | |
334 | union ubifs_key key; | |
335 | int err; | |
336 | ||
f4f61d2c | 337 | if (fname_len(&nm) > UBIFS_MAX_NLEN) |
2b88fc21 | 338 | return -ENAMETOOLONG; |
1e51764a AB |
339 | |
340 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
341 | if (!xent) | |
342 | return -ENOMEM; | |
343 | ||
1e51764a AB |
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); | |
6eb61d58 RW |
359 | ubifs_assert(c, inode->i_size == ui->data_len); |
360 | ubifs_assert(c, ubifs_inode(host)->xattr_size > ui->data_len); | |
1e51764a | 361 | |
ab92a20b | 362 | mutex_lock(&ui->ui_mutex); |
1e51764a AB |
363 | if (buf) { |
364 | /* If @buf is %NULL we are supposed to return the length */ | |
365 | if (ui->data_len > size) { | |
1e51764a AB |
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: | |
ab92a20b | 375 | mutex_unlock(&ui->ui_mutex); |
1e51764a AB |
376 | iput(inode); |
377 | out_unlock: | |
1e51764a AB |
378 | kfree(xent); |
379 | return err; | |
380 | } | |
381 | ||
43b113fe RW |
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 | ||
1e51764a AB |
396 | ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size) |
397 | { | |
398 | union ubifs_key key; | |
2b0143b5 | 399 | struct inode *host = d_inode(dentry); |
1e51764a AB |
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; | |
f4f61d2c | 404 | struct fscrypt_name nm = {0}; |
1e51764a | 405 | |
4cb2a01d AV |
406 | dbg_gen("ino %lu ('%pd'), buffer size %zd", host->i_ino, |
407 | dentry, size); | |
1e51764a AB |
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); | |
1e51764a | 421 | while (1) { |
1e51764a | 422 | xent = ubifs_tnc_next_ent(c, &key, &nm); |
8d47aef4 | 423 | if (IS_ERR(xent)) { |
1e51764a AB |
424 | err = PTR_ERR(xent); |
425 | break; | |
426 | } | |
427 | ||
f4f61d2c RW |
428 | fname_name(&nm) = xent->name; |
429 | fname_len(&nm) = le16_to_cpu(xent->nlen); | |
1e51764a | 430 | |
43b113fe | 431 | if (xattr_visible(xent->name)) { |
f4f61d2c RW |
432 | memcpy(buffer + written, fname_name(&nm), fname_len(&nm) + 1); |
433 | written += fname_len(&nm) + 1; | |
1e51764a AB |
434 | } |
435 | ||
436 | kfree(pxent); | |
437 | pxent = xent; | |
438 | key_read(c, &xent->key, &key); | |
439 | } | |
1e51764a AB |
440 | |
441 | kfree(pxent); | |
442 | if (err != -ENOENT) { | |
235c362b | 443 | ubifs_err(c, "cannot find next direntry, error %d", err); |
1e51764a AB |
444 | return err; |
445 | } | |
446 | ||
6eb61d58 | 447 | ubifs_assert(c, written <= size); |
1e51764a AB |
448 | return written; |
449 | } | |
450 | ||
451 | static int remove_xattr(struct ubifs_info *c, struct inode *host, | |
f4f61d2c | 452 | struct inode *inode, const struct fscrypt_name *nm) |
1e51764a AB |
453 | { |
454 | int err; | |
455 | struct ubifs_inode *host_ui = ubifs_inode(host); | |
456 | struct ubifs_inode *ui = ubifs_inode(inode); | |
5acd6ff8 ZS |
457 | struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1, |
458 | .dirtied_ino_d = ALIGN(host_ui->data_len, 8) }; | |
1e51764a | 459 | |
6eb61d58 | 460 | ubifs_assert(c, ui->data_len == inode->i_size); |
1e51764a AB |
461 | |
462 | err = ubifs_budget_space(c, &req); | |
463 | if (err) | |
464 | return err; | |
465 | ||
466 | mutex_lock(&host_ui->ui_mutex); | |
607a11ad | 467 | host->i_ctime = current_time(host); |
1e51764a | 468 | host_ui->xattr_cnt -= 1; |
f4f61d2c | 469 | host_ui->xattr_size -= CALC_DENT_SIZE(fname_len(nm)); |
1e51764a | 470 | host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len); |
f4f61d2c | 471 | host_ui->xattr_names -= fname_len(nm); |
1e51764a AB |
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; | |
f4f61d2c | 483 | host_ui->xattr_size += CALC_DENT_SIZE(fname_len(nm)); |
1e51764a | 484 | host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len); |
f4f61d2c | 485 | host_ui->xattr_names += fname_len(nm); |
1e51764a AB |
486 | mutex_unlock(&host_ui->ui_mutex); |
487 | ubifs_release_budget(c, &req); | |
488 | make_bad_inode(inode); | |
489 | return err; | |
490 | } | |
491 | ||
9ca2d732 RW |
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 | ||
4dd04815 | 518 | xino = ubifs_iget(c->vfs_sb, le64_to_cpu(xent->inum)); |
9ca2d732 RW |
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); | |
f2aae745 | 525 | kfree(xent); |
9ca2d732 RW |
526 | return err; |
527 | } | |
528 | ||
529 | ubifs_assert(c, ubifs_inode(xino)->xattr); | |
530 | ||
531 | clear_nlink(xino); | |
532 | err = remove_xattr(c, host, xino, &nm); | |
533 | if (err) { | |
534 | kfree(pxent); | |
f2aae745 | 535 | kfree(xent); |
9ca2d732 RW |
536 | iput(xino); |
537 | ubifs_err(c, "cannot remove xattr, error %d", err); | |
538 | return err; | |
539 | } | |
540 | ||
541 | iput(xino); | |
542 | ||
543 | kfree(pxent); | |
544 | pxent = xent; | |
545 | key_read(c, &xent->key, &key); | |
546 | } | |
547 | ||
548 | kfree(pxent); | |
549 | if (err != -ENOENT) { | |
550 | ubifs_err(c, "cannot find next direntry, error %d", err); | |
551 | return err; | |
552 | } | |
553 | ||
554 | return 0; | |
555 | } | |
556 | ||
272eda82 RW |
557 | /** |
558 | * ubifs_evict_xattr_inode - Evict an xattr inode. | |
559 | * @c: UBIFS file-system description object | |
560 | * @xattr_inum: xattr inode number | |
561 | * | |
562 | * When an inode that hosts xattrs is being removed we have to make sure | |
563 | * that cached inodes of the xattrs also get removed from the inode cache | |
564 | * otherwise we'd waste memory. This function looks up an inode from the | |
565 | * inode cache and clears the link counter such that iput() will evict | |
566 | * the inode. | |
567 | */ | |
568 | void ubifs_evict_xattr_inode(struct ubifs_info *c, ino_t xattr_inum) | |
569 | { | |
570 | struct inode *inode; | |
571 | ||
572 | inode = ilookup(c->vfs_sb, xattr_inum); | |
573 | if (inode) { | |
574 | clear_nlink(inode); | |
575 | iput(inode); | |
576 | } | |
577 | } | |
578 | ||
ade46c3a | 579 | static int ubifs_xattr_remove(struct inode *host, const char *name) |
1e51764a | 580 | { |
2b88fc21 | 581 | struct inode *inode; |
1e51764a | 582 | struct ubifs_info *c = host->i_sb->s_fs_info; |
f4f61d2c | 583 | struct fscrypt_name nm = { .disk_name = FSTR_INIT((char *)name, strlen(name))}; |
1e51764a AB |
584 | struct ubifs_dent_node *xent; |
585 | union ubifs_key key; | |
586 | int err; | |
587 | ||
6eb61d58 | 588 | ubifs_assert(c, inode_is_locked(host)); |
1e51764a | 589 | |
f4f61d2c | 590 | if (fname_len(&nm) > UBIFS_MAX_NLEN) |
2b88fc21 | 591 | return -ENAMETOOLONG; |
1e51764a AB |
592 | |
593 | xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS); | |
594 | if (!xent) | |
595 | return -ENOMEM; | |
596 | ||
597 | xent_key_init(c, &key, host->i_ino, &nm); | |
598 | err = ubifs_tnc_lookup_nm(c, &key, xent, &nm); | |
599 | if (err) { | |
600 | if (err == -ENOENT) | |
601 | err = -ENODATA; | |
602 | goto out_free; | |
603 | } | |
604 | ||
605 | inode = iget_xattr(c, le64_to_cpu(xent->inum)); | |
606 | if (IS_ERR(inode)) { | |
607 | err = PTR_ERR(inode); | |
608 | goto out_free; | |
609 | } | |
610 | ||
6eb61d58 | 611 | ubifs_assert(c, inode->i_nlink == 1); |
6d6b77f1 | 612 | clear_nlink(inode); |
1e51764a AB |
613 | err = remove_xattr(c, host, inode, &nm); |
614 | if (err) | |
bfe86848 | 615 | set_nlink(inode, 1); |
1e51764a AB |
616 | |
617 | /* If @i_nlink is 0, 'iput()' will delete the inode */ | |
618 | iput(inode); | |
619 | ||
620 | out_free: | |
621 | kfree(xent); | |
622 | return err; | |
623 | } | |
d7f0b70d | 624 | |
8326c1ee | 625 | #ifdef CONFIG_UBIFS_FS_SECURITY |
d7f0b70d SN |
626 | static int init_xattrs(struct inode *inode, const struct xattr *xattr_array, |
627 | void *fs_info) | |
628 | { | |
629 | const struct xattr *xattr; | |
630 | char *name; | |
631 | int err = 0; | |
632 | ||
633 | for (xattr = xattr_array; xattr->name != NULL; xattr++) { | |
634 | name = kmalloc(XATTR_SECURITY_PREFIX_LEN + | |
635 | strlen(xattr->name) + 1, GFP_NOFS); | |
636 | if (!name) { | |
637 | err = -ENOMEM; | |
638 | break; | |
639 | } | |
640 | strcpy(name, XATTR_SECURITY_PREFIX); | |
641 | strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name); | |
d8db5b1c XL |
642 | /* |
643 | * creating a new inode without holding the inode rwsem, | |
644 | * no need to check whether inode is locked. | |
645 | */ | |
ade46c3a | 646 | err = ubifs_xattr_set(inode, name, xattr->value, |
d8db5b1c | 647 | xattr->value_len, 0, false); |
d7f0b70d SN |
648 | kfree(name); |
649 | if (err < 0) | |
650 | break; | |
651 | } | |
652 | ||
653 | return err; | |
654 | } | |
655 | ||
656 | int ubifs_init_security(struct inode *dentry, struct inode *inode, | |
657 | const struct qstr *qstr) | |
658 | { | |
659 | int err; | |
660 | ||
d7f0b70d SN |
661 | err = security_inode_init_security(inode, dentry, qstr, |
662 | &init_xattrs, 0); | |
235c362b SY |
663 | if (err) { |
664 | struct ubifs_info *c = dentry->i_sb->s_fs_info; | |
665 | ubifs_err(c, "cannot initialize security for inode %lu, error %d", | |
fee1756d | 666 | inode->i_ino, err); |
235c362b | 667 | } |
d7f0b70d SN |
668 | return err; |
669 | } | |
8326c1ee | 670 | #endif |
2b88fc21 | 671 | |
ade46c3a | 672 | static int xattr_get(const struct xattr_handler *handler, |
2b88fc21 AG |
673 | struct dentry *dentry, struct inode *inode, |
674 | const char *name, void *buffer, size_t size) | |
675 | { | |
676 | dbg_gen("xattr '%s', ino %lu ('%pd'), buf size %zd", name, | |
677 | inode->i_ino, dentry, size); | |
678 | ||
17ce1eb0 | 679 | name = xattr_full_name(handler, name); |
ade46c3a | 680 | return ubifs_xattr_get(inode, name, buffer, size); |
2b88fc21 AG |
681 | } |
682 | ||
ade46c3a | 683 | static int xattr_set(const struct xattr_handler *handler, |
59301226 AV |
684 | struct dentry *dentry, struct inode *inode, |
685 | const char *name, const void *value, | |
686 | size_t size, int flags) | |
2b88fc21 | 687 | { |
2b88fc21 AG |
688 | dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd", |
689 | name, inode->i_ino, dentry, size); | |
690 | ||
17ce1eb0 RW |
691 | name = xattr_full_name(handler, name); |
692 | ||
2b88fc21 | 693 | if (value) |
d8db5b1c | 694 | return ubifs_xattr_set(inode, name, value, size, flags, true); |
2b88fc21 | 695 | else |
ade46c3a | 696 | return ubifs_xattr_remove(inode, name); |
2b88fc21 AG |
697 | } |
698 | ||
dfaf8d2a | 699 | static const struct xattr_handler ubifs_user_xattr_handler = { |
2b88fc21 | 700 | .prefix = XATTR_USER_PREFIX, |
ade46c3a RW |
701 | .get = xattr_get, |
702 | .set = xattr_set, | |
2b88fc21 AG |
703 | }; |
704 | ||
dfaf8d2a | 705 | static const struct xattr_handler ubifs_trusted_xattr_handler = { |
2b88fc21 | 706 | .prefix = XATTR_TRUSTED_PREFIX, |
ade46c3a RW |
707 | .get = xattr_get, |
708 | .set = xattr_set, | |
2b88fc21 AG |
709 | }; |
710 | ||
8326c1ee | 711 | #ifdef CONFIG_UBIFS_FS_SECURITY |
dfaf8d2a | 712 | static const struct xattr_handler ubifs_security_xattr_handler = { |
2b88fc21 | 713 | .prefix = XATTR_SECURITY_PREFIX, |
ade46c3a RW |
714 | .get = xattr_get, |
715 | .set = xattr_set, | |
2b88fc21 | 716 | }; |
8326c1ee | 717 | #endif |
2b88fc21 AG |
718 | |
719 | const struct xattr_handler *ubifs_xattr_handlers[] = { | |
720 | &ubifs_user_xattr_handler, | |
721 | &ubifs_trusted_xattr_handler, | |
8326c1ee | 722 | #ifdef CONFIG_UBIFS_FS_SECURITY |
2b88fc21 | 723 | &ubifs_security_xattr_handler, |
8326c1ee | 724 | #endif |
2b88fc21 AG |
725 | NULL |
726 | }; |