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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 int f2fs_xattr_generic_get(const struct xattr_handler *handler,
29 struct dentry *unused, struct inode *inode,
30 const char *name, void *buffer, size_t size)
31{
32 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
33
34 switch (handler->flags) {
35 case F2FS_XATTR_INDEX_USER:
36 if (!test_opt(sbi, XATTR_USER))
37 return -EOPNOTSUPP;
38 break;
39 case F2FS_XATTR_INDEX_TRUSTED:
40 if (!capable(CAP_SYS_ADMIN))
41 return -EPERM;
42 break;
43 case F2FS_XATTR_INDEX_SECURITY:
44 break;
45 default:
46 return -EINVAL;
47 }
48 return f2fs_getxattr(inode, handler->flags, name,
49 buffer, size, NULL);
50}
51
52static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
53 struct dentry *unused, struct inode *inode,
54 const char *name, const void *value,
55 size_t size, int flags)
56{
57 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
58
59 switch (handler->flags) {
60 case F2FS_XATTR_INDEX_USER:
61 if (!test_opt(sbi, XATTR_USER))
62 return -EOPNOTSUPP;
63 break;
64 case F2FS_XATTR_INDEX_TRUSTED:
65 if (!capable(CAP_SYS_ADMIN))
66 return -EPERM;
67 break;
68 case F2FS_XATTR_INDEX_SECURITY:
69 break;
70 default:
71 return -EINVAL;
72 }
73 return f2fs_setxattr(inode, handler->flags, name,
74 value, size, NULL, flags);
75}
76
77static bool f2fs_xattr_user_list(struct dentry *dentry)
78{
79 struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
80
81 return test_opt(sbi, XATTR_USER);
82}
83
84static bool f2fs_xattr_trusted_list(struct dentry *dentry)
85{
86 return capable(CAP_SYS_ADMIN);
87}
88
89static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
90 struct dentry *unused, struct inode *inode,
91 const char *name, void *buffer, size_t size)
92{
93 if (buffer)
94 *((char *)buffer) = F2FS_I(inode)->i_advise;
95 return sizeof(char);
96}
97
98static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
99 struct dentry *unused, struct inode *inode,
100 const char *name, const void *value,
101 size_t size, int flags)
102{
103 if (!inode_owner_or_capable(inode))
104 return -EPERM;
105 if (value == NULL)
106 return -EINVAL;
107
108 F2FS_I(inode)->i_advise |= *(char *)value;
109 f2fs_mark_inode_dirty_sync(inode, true);
110 return 0;
111}
112
113#ifdef CONFIG_F2FS_FS_SECURITY
114static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
115 void *page)
116{
117 const struct xattr *xattr;
118 int err = 0;
119
120 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
121 err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
122 xattr->name, xattr->value,
123 xattr->value_len, (struct page *)page, 0);
124 if (err < 0)
125 break;
126 }
127 return err;
128}
129
130int f2fs_init_security(struct inode *inode, struct inode *dir,
131 const struct qstr *qstr, struct page *ipage)
132{
133 return security_inode_init_security(inode, dir, qstr,
134 &f2fs_initxattrs, ipage);
135}
136#endif
137
138const struct xattr_handler f2fs_xattr_user_handler = {
139 .prefix = XATTR_USER_PREFIX,
140 .flags = F2FS_XATTR_INDEX_USER,
141 .list = f2fs_xattr_user_list,
142 .get = f2fs_xattr_generic_get,
143 .set = f2fs_xattr_generic_set,
144};
145
146const struct xattr_handler f2fs_xattr_trusted_handler = {
147 .prefix = XATTR_TRUSTED_PREFIX,
148 .flags = F2FS_XATTR_INDEX_TRUSTED,
149 .list = f2fs_xattr_trusted_list,
150 .get = f2fs_xattr_generic_get,
151 .set = f2fs_xattr_generic_set,
152};
153
154const struct xattr_handler f2fs_xattr_advise_handler = {
155 .name = F2FS_SYSTEM_ADVISE_NAME,
156 .flags = F2FS_XATTR_INDEX_ADVISE,
157 .get = f2fs_xattr_advise_get,
158 .set = f2fs_xattr_advise_set,
159};
160
161const struct xattr_handler f2fs_xattr_security_handler = {
162 .prefix = XATTR_SECURITY_PREFIX,
163 .flags = F2FS_XATTR_INDEX_SECURITY,
164 .get = f2fs_xattr_generic_get,
165 .set = f2fs_xattr_generic_set,
166};
167
168static const struct xattr_handler *f2fs_xattr_handler_map[] = {
169 [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler,
170#ifdef CONFIG_F2FS_FS_POSIX_ACL
171 [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler,
172 [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler,
173#endif
174 [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler,
175#ifdef CONFIG_F2FS_FS_SECURITY
176 [F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler,
177#endif
178 [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler,
179};
180
181const struct xattr_handler *f2fs_xattr_handlers[] = {
182 &f2fs_xattr_user_handler,
183#ifdef CONFIG_F2FS_FS_POSIX_ACL
184 &posix_acl_access_xattr_handler,
185 &posix_acl_default_xattr_handler,
186#endif
187 &f2fs_xattr_trusted_handler,
188#ifdef CONFIG_F2FS_FS_SECURITY
189 &f2fs_xattr_security_handler,
190#endif
191 &f2fs_xattr_advise_handler,
192 NULL,
193};
194
195static inline const struct xattr_handler *f2fs_xattr_handler(int index)
196{
197 const struct xattr_handler *handler = NULL;
198
199 if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map))
200 handler = f2fs_xattr_handler_map[index];
201 return handler;
202}
203
204static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int index,
205 size_t len, const char *name)
206{
207 struct f2fs_xattr_entry *entry;
208
209 list_for_each_xattr(entry, base_addr) {
210 if (entry->e_name_index != index)
211 continue;
212 if (entry->e_name_len != len)
213 continue;
214 if (!memcmp(entry->e_name, name, len))
215 break;
216 }
217 return entry;
218}
219
220static int read_all_xattrs(struct inode *inode, struct page *ipage,
221 void **base_addr)
222{
223 struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
224 struct f2fs_xattr_header *header;
225 size_t size = PAGE_SIZE, inline_size = 0;
226 void *txattr_addr;
227 int err;
228
229 inline_size = inline_xattr_size(inode);
230
231 txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO);
232 if (!txattr_addr)
233 return -ENOMEM;
234
235 /* read from inline xattr */
236 if (inline_size) {
237 struct page *page = NULL;
238 void *inline_addr;
239
240 if (ipage) {
241 inline_addr = inline_xattr_addr(ipage);
242 } else {
243 page = get_node_page(sbi, inode->i_ino);
244 if (IS_ERR(page)) {
245 err = PTR_ERR(page);
246 goto fail;
247 }
248 inline_addr = inline_xattr_addr(page);
249 }
250 memcpy(txattr_addr, inline_addr, inline_size);
251 f2fs_put_page(page, 1);
252 }
253
254 /* read from xattr node block */
255 if (F2FS_I(inode)->i_xattr_nid) {
256 struct page *xpage;
257 void *xattr_addr;
258
259 /* The inode already has an extended attribute block. */
260 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
261 if (IS_ERR(xpage)) {
262 err = PTR_ERR(xpage);
263 goto fail;
264 }
265
266 xattr_addr = page_address(xpage);
267 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE);
268 f2fs_put_page(xpage, 1);
269 }
270
271 header = XATTR_HDR(txattr_addr);
272
273 /* never been allocated xattrs */
274 if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) {
275 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC);
276 header->h_refcount = cpu_to_le32(1);
277 }
278 *base_addr = txattr_addr;
279 return 0;
280fail:
281 kzfree(txattr_addr);
282 return err;
283}
284
285static inline int write_all_xattrs(struct inode *inode, __u32 hsize,
286 void *txattr_addr, struct page *ipage)
287{
288 struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
289 size_t inline_size = 0;
290 void *xattr_addr;
291 struct page *xpage;
292 nid_t new_nid = 0;
293 int err;
294
295 inline_size = inline_xattr_size(inode);
296
297 if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid)
298 if (!alloc_nid(sbi, &new_nid))
299 return -ENOSPC;
300
301 /* write to inline xattr */
302 if (inline_size) {
303 struct page *page = NULL;
304 void *inline_addr;
305
306 if (ipage) {
307 inline_addr = inline_xattr_addr(ipage);
308 f2fs_wait_on_page_writeback(ipage, NODE, true);
309 set_page_dirty(ipage);
310 } else {
311 page = get_node_page(sbi, inode->i_ino);
312 if (IS_ERR(page)) {
313 alloc_nid_failed(sbi, new_nid);
314 return PTR_ERR(page);
315 }
316 inline_addr = inline_xattr_addr(page);
317 f2fs_wait_on_page_writeback(page, NODE, true);
318 }
319 memcpy(inline_addr, txattr_addr, inline_size);
320 f2fs_put_page(page, 1);
321
322 /* no need to use xattr node block */
323 if (hsize <= inline_size) {
324 err = truncate_xattr_node(inode, ipage);
325 alloc_nid_failed(sbi, new_nid);
326 return err;
327 }
328 }
329
330 /* write to xattr node block */
331 if (F2FS_I(inode)->i_xattr_nid) {
332 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid);
333 if (IS_ERR(xpage)) {
334 alloc_nid_failed(sbi, new_nid);
335 return PTR_ERR(xpage);
336 }
337 f2fs_bug_on(sbi, new_nid);
338 f2fs_wait_on_page_writeback(xpage, NODE, true);
339 } else {
340 struct dnode_of_data dn;
341 set_new_dnode(&dn, inode, NULL, NULL, new_nid);
342 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage);
343 if (IS_ERR(xpage)) {
344 alloc_nid_failed(sbi, new_nid);
345 return PTR_ERR(xpage);
346 }
347 alloc_nid_done(sbi, new_nid);
348 }
349
350 xattr_addr = page_address(xpage);
351 memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE -
352 sizeof(struct node_footer));
353 set_page_dirty(xpage);
354 f2fs_put_page(xpage, 1);
355
356 /* need to checkpoint during fsync */
357 F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
358 return 0;
359}
360
361int f2fs_getxattr(struct inode *inode, int index, const char *name,
362 void *buffer, size_t buffer_size, struct page *ipage)
363{
364 struct f2fs_xattr_entry *entry;
365 void *base_addr;
366 int error = 0;
367 size_t size, len;
368
369 if (name == NULL)
370 return -EINVAL;
371
372 len = strlen(name);
373 if (len > F2FS_NAME_LEN)
374 return -ERANGE;
375
376 error = read_all_xattrs(inode, ipage, &base_addr);
377 if (error)
378 return error;
379
380 entry = __find_xattr(base_addr, index, len, name);
381 if (IS_XATTR_LAST_ENTRY(entry)) {
382 error = -ENODATA;
383 goto cleanup;
384 }
385
386 size = le16_to_cpu(entry->e_value_size);
387
388 if (buffer && size > buffer_size) {
389 error = -ERANGE;
390 goto cleanup;
391 }
392
393 if (buffer) {
394 char *pval = entry->e_name + entry->e_name_len;
395 memcpy(buffer, pval, size);
396 }
397 error = size;
398
399cleanup:
400 kzfree(base_addr);
401 return error;
402}
403
404ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
405{
406 struct inode *inode = d_inode(dentry);
407 struct f2fs_xattr_entry *entry;
408 void *base_addr;
409 int error = 0;
410 size_t rest = buffer_size;
411
412 error = read_all_xattrs(inode, NULL, &base_addr);
413 if (error)
414 return error;
415
416 list_for_each_xattr(entry, base_addr) {
417 const struct xattr_handler *handler =
418 f2fs_xattr_handler(entry->e_name_index);
419 const char *prefix;
420 size_t prefix_len;
421 size_t size;
422
423 if (!handler || (handler->list && !handler->list(dentry)))
424 continue;
425
426 prefix = handler->prefix ?: handler->name;
427 prefix_len = strlen(prefix);
428 size = prefix_len + entry->e_name_len + 1;
429 if (buffer) {
430 if (size > rest) {
431 error = -ERANGE;
432 goto cleanup;
433 }
434 memcpy(buffer, prefix, prefix_len);
435 buffer += prefix_len;
436 memcpy(buffer, entry->e_name, entry->e_name_len);
437 buffer += entry->e_name_len;
438 *buffer++ = 0;
439 }
440 rest -= size;
441 }
442 error = buffer_size - rest;
443cleanup:
444 kzfree(base_addr);
445 return error;
446}
447
448static int __f2fs_setxattr(struct inode *inode, int index,
449 const char *name, const void *value, size_t size,
450 struct page *ipage, int flags)
451{
452 struct f2fs_xattr_entry *here, *last;
453 void *base_addr;
454 int found, newsize;
455 size_t len;
456 __u32 new_hsize;
457 int error = 0;
458
459 if (name == NULL)
460 return -EINVAL;
461
462 if (value == NULL)
463 size = 0;
464
465 len = strlen(name);
466
467 if (len > F2FS_NAME_LEN)
468 return -ERANGE;
469
470 if (size > MAX_VALUE_LEN(inode))
471 return -E2BIG;
472
473 error = read_all_xattrs(inode, ipage, &base_addr);
474 if (error)
475 return error;
476
477 /* find entry with wanted name. */
478 here = __find_xattr(base_addr, index, len, name);
479
480 found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1;
481
482 if ((flags & XATTR_REPLACE) && !found) {
483 error = -ENODATA;
484 goto exit;
485 } else if ((flags & XATTR_CREATE) && found) {
486 error = -EEXIST;
487 goto exit;
488 }
489
490 last = here;
491 while (!IS_XATTR_LAST_ENTRY(last))
492 last = XATTR_NEXT_ENTRY(last);
493
494 newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size);
495
496 /* 1. Check space */
497 if (value) {
498 int free;
499 /*
500 * If value is NULL, it is remove operation.
501 * In case of update operation, we calculate free.
502 */
503 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr);
504 if (found)
505 free = free + ENTRY_SIZE(here);
506
507 if (unlikely(free < newsize)) {
508 error = -E2BIG;
509 goto exit;
510 }
511 }
512
513 /* 2. Remove old entry */
514 if (found) {
515 /*
516 * If entry is found, remove old entry.
517 * If not found, remove operation is not needed.
518 */
519 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here);
520 int oldsize = ENTRY_SIZE(here);
521
522 memmove(here, next, (char *)last - (char *)next);
523 last = (struct f2fs_xattr_entry *)((char *)last - oldsize);
524 memset(last, 0, oldsize);
525 }
526
527 new_hsize = (char *)last - (char *)base_addr;
528
529 /* 3. Write new entry */
530 if (value) {
531 char *pval;
532 /*
533 * Before we come here, old entry is removed.
534 * We just write new entry.
535 */
536 last->e_name_index = index;
537 last->e_name_len = len;
538 memcpy(last->e_name, name, len);
539 pval = last->e_name + len;
540 memcpy(pval, value, size);
541 last->e_value_size = cpu_to_le16(size);
542 new_hsize += newsize;
543 }
544
545 error = write_all_xattrs(inode, new_hsize, base_addr, ipage);
546 if (error)
547 goto exit;
548
549 if (is_inode_flag_set(inode, FI_ACL_MODE)) {
550 inode->i_mode = F2FS_I(inode)->i_acl_mode;
551 inode->i_ctime = current_time(inode);
552 clear_inode_flag(inode, FI_ACL_MODE);
553 }
554 if (index == F2FS_XATTR_INDEX_ENCRYPTION &&
555 !strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT))
556 f2fs_set_encrypted_inode(inode);
557 f2fs_mark_inode_dirty_sync(inode, true);
558 if (!error && S_ISDIR(inode->i_mode))
559 set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP);
560exit:
561 kzfree(base_addr);
562 return error;
563}
564
565int f2fs_setxattr(struct inode *inode, int index, const char *name,
566 const void *value, size_t size,
567 struct page *ipage, int flags)
568{
569 struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
570 int err;
571
572 /* this case is only from init_inode_metadata */
573 if (ipage)
574 return __f2fs_setxattr(inode, index, name, value,
575 size, ipage, flags);
576 f2fs_balance_fs(sbi, true);
577
578 f2fs_lock_op(sbi);
579 /* protect xattr_ver */
580 down_write(&F2FS_I(inode)->i_sem);
581 err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags);
582 up_write(&F2FS_I(inode)->i_sem);
583 f2fs_unlock_op(sbi);
584
585 f2fs_update_time(sbi, REQ_TIME);
586 return err;
587}