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1/*
2 * fs/f2fs/xattr.c
3 *
4 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5 * http://www.samsung.com/
6 *
7 * Portions of this code from linux/fs/ext2/xattr.c
8 *
9 * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
10 *
11 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
12 * Extended attributes for symlinks and special files added per
13 * suggestion of Luka Renko <luka.renko@hermes.si>.
14 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
15 * Red Hat Inc.
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License version 2 as
19 * published by the Free Software Foundation.
20 */
21#include <linux/rwsem.h>
22#include <linux/f2fs_fs.h>
23#include <linux/security.h>
24#include <linux/posix_acl_xattr.h>
25#include "f2fs.h"
26#include "xattr.h"
27
28static size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list,
29 size_t list_size, const char *name, size_t name_len, int type)
30{
31 struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
32 int total_len, prefix_len = 0;
33 const char *prefix = NULL;
34
35 switch (type) {
36 case F2FS_XATTR_INDEX_USER:
37 if (!test_opt(sbi, XATTR_USER))
38 return -EOPNOTSUPP;
39 prefix = XATTR_USER_PREFIX;
40 prefix_len = XATTR_USER_PREFIX_LEN;
41 break;
42 case F2FS_XATTR_INDEX_TRUSTED:
43 if (!capable(CAP_SYS_ADMIN))
44 return -EPERM;
45 prefix = XATTR_TRUSTED_PREFIX;
46 prefix_len = XATTR_TRUSTED_PREFIX_LEN;
47 break;
48 case F2FS_XATTR_INDEX_SECURITY:
49 prefix = XATTR_SECURITY_PREFIX;
50 prefix_len = XATTR_SECURITY_PREFIX_LEN;
51 break;
52 default:
53 return -EINVAL;
54 }
55
56 total_len = prefix_len + name_len + 1;
57 if (list && total_len <= list_size) {
58 memcpy(list, prefix, prefix_len);
59 memcpy(list + prefix_len, name, name_len);
60 list[prefix_len + name_len] = '\0';
61 }
62 return total_len;
63}
64
65static int f2fs_xattr_generic_get(struct dentry *dentry, const char *name,
66 void *buffer, size_t size, int type)
67{
68 struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
69
70 switch (type) {
71 case F2FS_XATTR_INDEX_USER:
72 if (!test_opt(sbi, XATTR_USER))
73 return -EOPNOTSUPP;
74 break;
75 case F2FS_XATTR_INDEX_TRUSTED:
76 if (!capable(CAP_SYS_ADMIN))
77 return -EPERM;
78 break;
79 case F2FS_XATTR_INDEX_SECURITY:
80 break;
81 default:
82 return -EINVAL;
83 }
84 if (strcmp(name, "") == 0)
85 return -EINVAL;
86 return f2fs_getxattr(dentry->d_inode, type, name, buffer, size);
87}
88
89static int f2fs_xattr_generic_set(struct dentry *dentry, const char *name,
90 const void *value, size_t size, int flags, int type)
91{
92 struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
93
94 switch (type) {
95 case F2FS_XATTR_INDEX_USER:
96 if (!test_opt(sbi, XATTR_USER))
97 return -EOPNOTSUPP;
98 break;
99 case F2FS_XATTR_INDEX_TRUSTED:
100 if (!capable(CAP_SYS_ADMIN))
101 return -EPERM;
102 break;
103 case F2FS_XATTR_INDEX_SECURITY:
104 break;
105 default:
106 return -EINVAL;
107 }
108 if (strcmp(name, "") == 0)
109 return -EINVAL;
110
111 return f2fs_setxattr(dentry->d_inode, type, name, value, size, NULL);
112}
113
114static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list,
115 size_t list_size, const char *name, size_t name_len, int type)
116{
117 const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
118 size_t size;
119
120 if (type != F2FS_XATTR_INDEX_ADVISE)
121 return 0;
122
123 size = strlen(xname) + 1;
124 if (list && size <= list_size)
125 memcpy(list, xname, size);
126 return size;
127}
128
129static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name,
130 void *buffer, size_t size, int type)
131{
132 struct inode *inode = dentry->d_inode;
133
134 if (strcmp(name, "") != 0)
135 return -EINVAL;
136
137 *((char *)buffer) = F2FS_I(inode)->i_advise;
138 return sizeof(char);
139}
140
141static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name,
142 const void *value, size_t size, int flags, int type)
143{
144 struct inode *inode = dentry->d_inode;
145
146 if (strcmp(name, "") != 0)
147 return -EINVAL;
148 if (!inode_owner_or_capable(inode))
149 return -EPERM;
150 if (value == NULL)
151 return -EINVAL;
152
153 F2FS_I(inode)->i_advise |= *(char *)value;
154 return 0;
155}
156
157#ifdef CONFIG_F2FS_FS_SECURITY
158static int __f2fs_setxattr(struct inode *inode, int name_index,
159 const char *name, const void *value, size_t value_len,
160 struct page *ipage);
161static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
162 void *page)
163{
164 const struct xattr *xattr;
165 int err = 0;
166
167 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
168 err = __f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
169 xattr->name, xattr->value,
170 xattr->value_len, (struct page *)page);
171 if (err < 0)
172 break;
173 }
174 return err;
175}
176
177int f2fs_init_security(struct inode *inode, struct inode *dir,
178 const struct qstr *qstr, struct page *ipage)
179{
180 return security_inode_init_security(inode, dir, qstr,
181 &f2fs_initxattrs, ipage);
182}
183#endif
184
185const struct xattr_handler f2fs_xattr_user_handler = {
186 .prefix = XATTR_USER_PREFIX,
187 .flags = F2FS_XATTR_INDEX_USER,
188 .list = f2fs_xattr_generic_list,
189 .get = f2fs_xattr_generic_get,
190 .set = f2fs_xattr_generic_set,
191};
192
193const struct xattr_handler f2fs_xattr_trusted_handler = {
194 .prefix = XATTR_TRUSTED_PREFIX,
195 .flags = F2FS_XATTR_INDEX_TRUSTED,
196 .list = f2fs_xattr_generic_list,
197 .get = f2fs_xattr_generic_get,
198 .set = f2fs_xattr_generic_set,
199};
200
201const struct xattr_handler f2fs_xattr_advise_handler = {
202 .prefix = F2FS_SYSTEM_ADVISE_PREFIX,
203 .flags = F2FS_XATTR_INDEX_ADVISE,
204 .list = f2fs_xattr_advise_list,
205 .get = f2fs_xattr_advise_get,
206 .set = f2fs_xattr_advise_set,
207};
208
209const struct xattr_handler f2fs_xattr_security_handler = {
210 .prefix = XATTR_SECURITY_PREFIX,
211 .flags = F2FS_XATTR_INDEX_SECURITY,
212 .list = f2fs_xattr_generic_list,
213 .get = f2fs_xattr_generic_get,
214 .set = f2fs_xattr_generic_set,
215};
216
217static const struct xattr_handler *f2fs_xattr_handler_map[] = {
218 [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
219#ifdef CONFIG_F2FS_FS_POSIX_ACL
220 [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
221 [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
222#endif
223 [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
224#ifdef CONFIG_F2FS_FS_SECURITY
225 [F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
226#endif
227 [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
228};
229
230const struct xattr_handler *f2fs_xattr_handlers[] = {
231 &f2fs_xattr_user_handler,
232#ifdef CONFIG_F2FS_FS_POSIX_ACL
233 &posix_acl_access_xattr_handler,
234 &posix_acl_default_xattr_handler,
235#endif
236 &f2fs_xattr_trusted_handler,
237#ifdef CONFIG_F2FS_FS_SECURITY
238 &f2fs_xattr_security_handler,
239#endif
240 &f2fs_xattr_advise_handler,
241 NULL,
242};
243
244static inline const struct xattr_handler *f2fs_xattr_handler(int name_index)
245{
246 const struct xattr_handler *handler = NULL;
247
248 if (name_index > 0 && name_index < ARRAY_SIZE(f2fs_xattr_handler_map))
249 handler = f2fs_xattr_handler_map[name_index];
250 return handler;
251}
252
253static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int name_index,
254 size_t name_len, const char *name)
255{
256 struct f2fs_xattr_entry *entry;
257
258 list_for_each_xattr(entry, base_addr) {
259 if (entry->e_name_index != name_index)
260 continue;
261 if (entry->e_name_len != name_len)
262 continue;
263 if (!memcmp(entry->e_name, name, name_len))
264 break;
265 }
266 return entry;
267}
268
269static void *read_all_xattrs(struct inode *inode, struct page *ipage)
270{
271 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
272 struct f2fs_xattr_header *header;
273 size_t size = PAGE_SIZE, inline_size = 0;
274 void *txattr_addr;
275
276 inline_size = inline_xattr_size(inode);
277
278 txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO);
279 if (!txattr_addr)
280 return NULL;
281
282 /* read from inline xattr */
283 if (inline_size) {
284 struct page *page = NULL;
285 void *inline_addr;
286
287 if (ipage) {
288 inline_addr = inline_xattr_addr(ipage);
289 } else {
290 page = get_node_page(sbi, inode->i_ino);
291 if (IS_ERR(page))
292 goto fail;
293 inline_addr = inline_xattr_addr(page);
294 }
295 memcpy(txattr_addr, inline_addr, inline_size);
296 f2fs_put_page(page, 1);
297 }
298
299 /* read from xattr node block */
300 if (F2FS_I(inode)->i_xattr_nid) {
301 struct page *xpage;
302 void *xattr_addr;
303
304 /* The inode already has an extended attribute block. */
305 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
306 if (IS_ERR(xpage))
307 goto fail;
308
309 xattr_addr = page_address(xpage);
310 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
311 f2fs_put_page(xpage, 1);
312 }
313
314 header = XATTR_HDR(txattr_addr);
315
316 /* never been allocated xattrs */
317 if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
318 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
319 header->h_refcount = cpu_to_le32(1);
320 }
321 return txattr_addr;
322fail:
323 kzfree(txattr_addr);
324 return NULL;
325}
326
327static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
328 void *txattr_addr, struct page *ipage)
329{
330 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
331 size_t inline_size = 0;
332 void *xattr_addr;
333 struct page *xpage;
334 nid_t new_nid = 0;
335 int err;
336
337 inline_size = inline_xattr_size(inode);
338
339 if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
340 if (!alloc_nid(sbi, &new_nid))
341 return -ENOSPC;
342
343 /* write to inline xattr */
344 if (inline_size) {
345 struct page *page = NULL;
346 void *inline_addr;
347
348 if (ipage) {
349 inline_addr = inline_xattr_addr(ipage);
350 } else {
351 page = get_node_page(sbi, inode->i_ino);
352 if (IS_ERR(page)) {
353 alloc_nid_failed(sbi, new_nid);
354 return PTR_ERR(page);
355 }
356 inline_addr = inline_xattr_addr(page);
357 }
358 memcpy(inline_addr, txattr_addr, inline_size);
359 f2fs_put_page(page, 1);
360
361 /* no need to use xattr node block */
362 if (hsize <= inline_size) {
363 err = truncate_xattr_node(inode, ipage);
364 alloc_nid_failed(sbi, new_nid);
365 return err;
366 }
367 }
368
369 /* write to xattr node block */
370 if (F2FS_I(inode)->i_xattr_nid) {
371 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
372 if (IS_ERR(xpage)) {
373 alloc_nid_failed(sbi, new_nid);
374 return PTR_ERR(xpage);
375 }
376 f2fs_bug_on(new_nid);
377 } else {
378 struct dnode_of_data dn;
379 set_new_dnode(&dn, inode, NULL, NULL, new_nid);
380 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
381 if (IS_ERR(xpage)) {
382 alloc_nid_failed(sbi, new_nid);
383 return PTR_ERR(xpage);
384 }
385 alloc_nid_done(sbi, new_nid);
386 }
387
388 xattr_addr = page_address(xpage);
389 memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
390 sizeof(struct node_footer));
391 set_page_dirty(xpage);
392 f2fs_put_page(xpage, 1);
393
394 /* need to checkpoint during fsync */
395 F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
396 return 0;
397}
398
399int f2fs_getxattr(struct inode *inode, int name_index, const char *name,
400 void *buffer, size_t buffer_size)
401{
402 struct f2fs_xattr_entry *entry;
403 void *base_addr;
404 int error = 0;
405 size_t value_len, name_len;
406
407 if (name == NULL)
408 return -EINVAL;
409 name_len = strlen(name);
410 if (name_len > F2FS_NAME_LEN)
411 return -ERANGE;
412
413 base_addr = read_all_xattrs(inode, NULL);
414 if (!base_addr)
415 return -ENOMEM;
416
417 entry = __find_xattr(base_addr, name_index, name_len, name);
418 if (IS_XATTR_LAST_ENTRY(entry)) {
419 error = -ENODATA;
420 goto cleanup;
421 }
422
423 value_len = le16_to_cpu(entry->e_value_size);
424
425 if (buffer && value_len > buffer_size) {
426 error = -ERANGE;
427 goto cleanup;
428 }
429
430 if (buffer) {
431 char *pval = entry->e_name + entry->e_name_len;
432 memcpy(buffer, pval, value_len);
433 }
434 error = value_len;
435
436cleanup:
437 kzfree(base_addr);
438 return error;
439}
440
441ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
442{
443 struct inode *inode = dentry->d_inode;
444 struct f2fs_xattr_entry *entry;
445 void *base_addr;
446 int error = 0;
447 size_t rest = buffer_size;
448
449 base_addr = read_all_xattrs(inode, NULL);
450 if (!base_addr)
451 return -ENOMEM;
452
453 list_for_each_xattr(entry, base_addr) {
454 const struct xattr_handler *handler =
455 f2fs_xattr_handler(entry->e_name_index);
456 size_t size;
457
458 if (!handler)
459 continue;
460
461 size = handler->list(dentry, buffer, rest, entry->e_name,
462 entry->e_name_len, handler->flags);
463 if (buffer && size > rest) {
464 error = -ERANGE;
465 goto cleanup;
466 }
467
468 if (buffer)
469 buffer += size;
470 rest -= size;
471 }
472 error = buffer_size - rest;
473cleanup:
474 kzfree(base_addr);
475 return error;
476}
477
478static int __f2fs_setxattr(struct inode *inode, int name_index,
479 const char *name, const void *value, size_t value_len,
480 struct page *ipage)
481{
482 struct f2fs_inode_info *fi = F2FS_I(inode);
483 struct f2fs_xattr_entry *here, *last;
484 void *base_addr;
485 int found, newsize;
486 size_t name_len;
487 __u32 new_hsize;
488 int error = -ENOMEM;
489
490 if (name == NULL)
491 return -EINVAL;
492
493 if (value == NULL)
494 value_len = 0;
495
496 name_len = strlen(name);
497
498 if (name_len > F2FS_NAME_LEN || value_len > MAX_VALUE_LEN(inode))
499 return -ERANGE;
500
501 base_addr = read_all_xattrs(inode, ipage);
502 if (!base_addr)
503 goto exit;
504
505 /* find entry with wanted name. */
506 here = __find_xattr(base_addr, name_index, name_len, name);
507
508 found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
509 last = here;
510
511 while (!IS_XATTR_LAST_ENTRY(last))
512 last = XATTR_NEXT_ENTRY(last);
513
514 newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) +
515 name_len + value_len);
516
517 /* 1. Check space */
518 if (value) {
519 int free;
520 /*
521 * If value is NULL, it is remove operation.
522 * In case of update operation, we caculate free.
523 */
524 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
525 if (found)
526 free = free + ENTRY_SIZE(here);
527
528 if (unlikely(free < newsize)) {
529 error = -ENOSPC;
530 goto exit;
531 }
532 }
533
534 /* 2. Remove old entry */
535 if (found) {
536 /*
537 * If entry is found, remove old entry.
538 * If not found, remove operation is not needed.
539 */
540 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
541 int oldsize = ENTRY_SIZE(here);
542
543 memmove(here, next, (char *)last - (char *)next);
544 last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
545 memset(last, 0, oldsize);
546 }
547
548 new_hsize = (char *)last - (char *)base_addr;
549
550 /* 3. Write new entry */
551 if (value) {
552 char *pval;
553 /*
554 * Before we come here, old entry is removed.
555 * We just write new entry.
556 */
557 memset(last, 0, newsize);
558 last->e_name_index = name_index;
559 last->e_name_len = name_len;
560 memcpy(last->e_name, name, name_len);
561 pval = last->e_name + name_len;
562 memcpy(pval, value, value_len);
563 last->e_value_size = cpu_to_le16(value_len);
564 new_hsize += newsize;
565 }
566
567 error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
568 if (error)
569 goto exit;
570
571 if (is_inode_flag_set(fi, FI_ACL_MODE)) {
572 inode->i_mode = fi->i_acl_mode;
573 inode->i_ctime = CURRENT_TIME;
574 clear_inode_flag(fi, FI_ACL_MODE);
575 }
576
577 if (ipage)
578 update_inode(inode, ipage);
579 else
580 update_inode_page(inode);
581exit:
582 kzfree(base_addr);
583 return error;
584}
585
586int f2fs_setxattr(struct inode *inode, int name_index, const char *name,
587 const void *value, size_t value_len, struct page *ipage)
588{
589 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
590 int err;
591
592 f2fs_balance_fs(sbi);
593
594 f2fs_lock_op(sbi);
595 /* protect xattr_ver */
596 down_write(&F2FS_I(inode)->i_sem);
597 err = __f2fs_setxattr(inode, name_index, name, value, value_len, ipage);
598 up_write(&F2FS_I(inode)->i_sem);
599 f2fs_unlock_op(sbi);
600
601 return err;
602}