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 28 static 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 52 static 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 77 static 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 84 static bool f2fs_xattr_trusted_list(struct dentry *dentry) 85 { 86 return capable(CAP_SYS_ADMIN); 87 } 88 89 static 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 98 static 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 114 static 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 } 129 130 int 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 137 138 const 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 }; 145 146 const 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 }; 153 154 const 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 }; 160 161 const 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 }; 167 168 static 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 }; 180 181 const 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 }; 194 195 static 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 } 203 204 static 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 } 219 220 static struct f2fs_xattr_entry *__find_inline_xattr(void *base_addr, 221 void **last_addr, int index, 222 size_t len, const char *name) 223 { 224 struct f2fs_xattr_entry *entry; 225 unsigned int inline_size = F2FS_INLINE_XATTR_ADDRS << 2; 226 227 list_for_each_xattr(entry, base_addr) { 228 if ((void *)entry + sizeof(__u32) > base_addr + inline_size || 229 (void *)XATTR_NEXT_ENTRY(entry) + sizeof(__u32) > 230 base_addr + inline_size) { 231 *last_addr = entry; 232 return NULL; 233 } 234 if (entry->e_name_index != index) 235 continue; 236 if (entry->e_name_len != len) 237 continue; 238 if (!memcmp(entry->e_name, name, len)) 239 break; 240 } 241 return entry; 242 } 243 244 static int lookup_all_xattrs(struct inode *inode, struct page *ipage, 245 unsigned int index, unsigned int len, 246 const char *name, struct f2fs_xattr_entry **xe, 247 void **base_addr) 248 { 249 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 250 void *cur_addr, *txattr_addr, *last_addr = NULL; 251 nid_t xnid = F2FS_I(inode)->i_xattr_nid; 252 unsigned int size = xnid ? VALID_XATTR_BLOCK_SIZE : 0; 253 unsigned int inline_size = inline_xattr_size(inode); 254 int err = 0; 255 256 if (!size && !inline_size) 257 return -ENODATA; 258 259 txattr_addr = kzalloc(inline_size + size + XATTR_PADDING_SIZE, 260 GFP_F2FS_ZERO); 261 if (!txattr_addr) 262 return -ENOMEM; 263 264 /* read from inline xattr */ 265 if (inline_size) { 266 struct page *page = NULL; 267 void *inline_addr; 268 269 if (ipage) { 270 inline_addr = inline_xattr_addr(ipage); 271 } else { 272 page = get_node_page(sbi, inode->i_ino); 273 if (IS_ERR(page)) { 274 err = PTR_ERR(page); 275 goto out; 276 } 277 inline_addr = inline_xattr_addr(page); 278 } 279 memcpy(txattr_addr, inline_addr, inline_size); 280 f2fs_put_page(page, 1); 281 282 *xe = __find_inline_xattr(txattr_addr, &last_addr, 283 index, len, name); 284 if (*xe) 285 goto check; 286 } 287 288 /* read from xattr node block */ 289 if (xnid) { 290 struct page *xpage; 291 void *xattr_addr; 292 293 /* The inode already has an extended attribute block. */ 294 xpage = get_node_page(sbi, xnid); 295 if (IS_ERR(xpage)) { 296 err = PTR_ERR(xpage); 297 goto out; 298 } 299 300 xattr_addr = page_address(xpage); 301 memcpy(txattr_addr + inline_size, xattr_addr, size); 302 f2fs_put_page(xpage, 1); 303 } 304 305 if (last_addr) 306 cur_addr = XATTR_HDR(last_addr) - 1; 307 else 308 cur_addr = txattr_addr; 309 310 *xe = __find_xattr(cur_addr, index, len, name); 311 check: 312 if (IS_XATTR_LAST_ENTRY(*xe)) { 313 err = -ENODATA; 314 goto out; 315 } 316 317 *base_addr = txattr_addr; 318 return 0; 319 out: 320 kzfree(txattr_addr); 321 return err; 322 } 323 324 static int read_all_xattrs(struct inode *inode, struct page *ipage, 325 void **base_addr) 326 { 327 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 328 struct f2fs_xattr_header *header; 329 nid_t xnid = F2FS_I(inode)->i_xattr_nid; 330 unsigned int size = VALID_XATTR_BLOCK_SIZE; 331 unsigned int inline_size = inline_xattr_size(inode); 332 void *txattr_addr; 333 int err; 334 335 txattr_addr = kzalloc(inline_size + size + XATTR_PADDING_SIZE, 336 GFP_F2FS_ZERO); 337 if (!txattr_addr) 338 return -ENOMEM; 339 340 /* read from inline xattr */ 341 if (inline_size) { 342 struct page *page = NULL; 343 void *inline_addr; 344 345 if (ipage) { 346 inline_addr = inline_xattr_addr(ipage); 347 } else { 348 page = get_node_page(sbi, inode->i_ino); 349 if (IS_ERR(page)) { 350 err = PTR_ERR(page); 351 goto fail; 352 } 353 inline_addr = inline_xattr_addr(page); 354 } 355 memcpy(txattr_addr, inline_addr, inline_size); 356 f2fs_put_page(page, 1); 357 } 358 359 /* read from xattr node block */ 360 if (xnid) { 361 struct page *xpage; 362 void *xattr_addr; 363 364 /* The inode already has an extended attribute block. */ 365 xpage = get_node_page(sbi, xnid); 366 if (IS_ERR(xpage)) { 367 err = PTR_ERR(xpage); 368 goto fail; 369 } 370 371 xattr_addr = page_address(xpage); 372 memcpy(txattr_addr + inline_size, xattr_addr, size); 373 f2fs_put_page(xpage, 1); 374 } 375 376 header = XATTR_HDR(txattr_addr); 377 378 /* never been allocated xattrs */ 379 if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) { 380 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC); 381 header->h_refcount = cpu_to_le32(1); 382 } 383 *base_addr = txattr_addr; 384 return 0; 385 fail: 386 kzfree(txattr_addr); 387 return err; 388 } 389 390 static inline int write_all_xattrs(struct inode *inode, __u32 hsize, 391 void *txattr_addr, struct page *ipage) 392 { 393 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 394 size_t inline_size = inline_xattr_size(inode); 395 void *xattr_addr; 396 struct page *xpage; 397 nid_t new_nid = 0; 398 int err; 399 400 if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid) 401 if (!alloc_nid(sbi, &new_nid)) 402 return -ENOSPC; 403 404 /* write to inline xattr */ 405 if (inline_size) { 406 struct page *page = NULL; 407 void *inline_addr; 408 409 if (ipage) { 410 inline_addr = inline_xattr_addr(ipage); 411 f2fs_wait_on_page_writeback(ipage, NODE, true); 412 set_page_dirty(ipage); 413 } else { 414 page = get_node_page(sbi, inode->i_ino); 415 if (IS_ERR(page)) { 416 alloc_nid_failed(sbi, new_nid); 417 return PTR_ERR(page); 418 } 419 inline_addr = inline_xattr_addr(page); 420 f2fs_wait_on_page_writeback(page, NODE, true); 421 } 422 memcpy(inline_addr, txattr_addr, inline_size); 423 f2fs_put_page(page, 1); 424 425 /* no need to use xattr node block */ 426 if (hsize <= inline_size) { 427 err = truncate_xattr_node(inode, ipage); 428 alloc_nid_failed(sbi, new_nid); 429 return err; 430 } 431 } 432 433 /* write to xattr node block */ 434 if (F2FS_I(inode)->i_xattr_nid) { 435 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 436 if (IS_ERR(xpage)) { 437 alloc_nid_failed(sbi, new_nid); 438 return PTR_ERR(xpage); 439 } 440 f2fs_bug_on(sbi, new_nid); 441 f2fs_wait_on_page_writeback(xpage, NODE, true); 442 } else { 443 struct dnode_of_data dn; 444 set_new_dnode(&dn, inode, NULL, NULL, new_nid); 445 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage); 446 if (IS_ERR(xpage)) { 447 alloc_nid_failed(sbi, new_nid); 448 return PTR_ERR(xpage); 449 } 450 alloc_nid_done(sbi, new_nid); 451 } 452 453 xattr_addr = page_address(xpage); 454 memcpy(xattr_addr, txattr_addr + inline_size, VALID_XATTR_BLOCK_SIZE); 455 set_page_dirty(xpage); 456 f2fs_put_page(xpage, 1); 457 458 return 0; 459 } 460 461 int f2fs_getxattr(struct inode *inode, int index, const char *name, 462 void *buffer, size_t buffer_size, struct page *ipage) 463 { 464 struct f2fs_xattr_entry *entry = NULL; 465 int error = 0; 466 unsigned int size, len; 467 void *base_addr = NULL; 468 469 if (name == NULL) 470 return -EINVAL; 471 472 len = strlen(name); 473 if (len > F2FS_NAME_LEN) 474 return -ERANGE; 475 476 error = lookup_all_xattrs(inode, ipage, index, len, name, 477 &entry, &base_addr); 478 if (error) 479 return error; 480 481 size = le16_to_cpu(entry->e_value_size); 482 483 if (buffer && size > buffer_size) { 484 error = -ERANGE; 485 goto out; 486 } 487 488 if (buffer) { 489 char *pval = entry->e_name + entry->e_name_len; 490 memcpy(buffer, pval, size); 491 } 492 error = size; 493 out: 494 kzfree(base_addr); 495 return error; 496 } 497 498 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 499 { 500 struct inode *inode = d_inode(dentry); 501 struct f2fs_xattr_entry *entry; 502 void *base_addr; 503 int error = 0; 504 size_t rest = buffer_size; 505 506 error = read_all_xattrs(inode, NULL, &base_addr); 507 if (error) 508 return error; 509 510 list_for_each_xattr(entry, base_addr) { 511 const struct xattr_handler *handler = 512 f2fs_xattr_handler(entry->e_name_index); 513 const char *prefix; 514 size_t prefix_len; 515 size_t size; 516 517 if (!handler || (handler->list && !handler->list(dentry))) 518 continue; 519 520 prefix = handler->prefix ?: handler->name; 521 prefix_len = strlen(prefix); 522 size = prefix_len + entry->e_name_len + 1; 523 if (buffer) { 524 if (size > rest) { 525 error = -ERANGE; 526 goto cleanup; 527 } 528 memcpy(buffer, prefix, prefix_len); 529 buffer += prefix_len; 530 memcpy(buffer, entry->e_name, entry->e_name_len); 531 buffer += entry->e_name_len; 532 *buffer++ = 0; 533 } 534 rest -= size; 535 } 536 error = buffer_size - rest; 537 cleanup: 538 kzfree(base_addr); 539 return error; 540 } 541 542 static bool f2fs_xattr_value_same(struct f2fs_xattr_entry *entry, 543 const void *value, size_t size) 544 { 545 void *pval = entry->e_name + entry->e_name_len; 546 547 return (le16_to_cpu(entry->e_value_size) == size) && 548 !memcmp(pval, value, size); 549 } 550 551 static int __f2fs_setxattr(struct inode *inode, int index, 552 const char *name, const void *value, size_t size, 553 struct page *ipage, int flags) 554 { 555 struct f2fs_xattr_entry *here, *last; 556 void *base_addr; 557 int found, newsize; 558 size_t len; 559 __u32 new_hsize; 560 int error = 0; 561 562 if (name == NULL) 563 return -EINVAL; 564 565 if (value == NULL) 566 size = 0; 567 568 len = strlen(name); 569 570 if (len > F2FS_NAME_LEN) 571 return -ERANGE; 572 573 if (size > MAX_VALUE_LEN(inode)) 574 return -E2BIG; 575 576 error = read_all_xattrs(inode, ipage, &base_addr); 577 if (error) 578 return error; 579 580 /* find entry with wanted name. */ 581 here = __find_xattr(base_addr, index, len, name); 582 583 found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1; 584 585 if (found) { 586 if ((flags & XATTR_CREATE)) { 587 error = -EEXIST; 588 goto exit; 589 } 590 591 if (f2fs_xattr_value_same(here, value, size)) 592 goto exit; 593 } else if ((flags & XATTR_REPLACE)) { 594 error = -ENODATA; 595 goto exit; 596 } 597 598 last = here; 599 while (!IS_XATTR_LAST_ENTRY(last)) 600 last = XATTR_NEXT_ENTRY(last); 601 602 newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size); 603 604 /* 1. Check space */ 605 if (value) { 606 int free; 607 /* 608 * If value is NULL, it is remove operation. 609 * In case of update operation, we calculate free. 610 */ 611 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr); 612 if (found) 613 free = free + ENTRY_SIZE(here); 614 615 if (unlikely(free < newsize)) { 616 error = -E2BIG; 617 goto exit; 618 } 619 } 620 621 /* 2. Remove old entry */ 622 if (found) { 623 /* 624 * If entry is found, remove old entry. 625 * If not found, remove operation is not needed. 626 */ 627 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here); 628 int oldsize = ENTRY_SIZE(here); 629 630 memmove(here, next, (char *)last - (char *)next); 631 last = (struct f2fs_xattr_entry *)((char *)last - oldsize); 632 memset(last, 0, oldsize); 633 } 634 635 new_hsize = (char *)last - (char *)base_addr; 636 637 /* 3. Write new entry */ 638 if (value) { 639 char *pval; 640 /* 641 * Before we come here, old entry is removed. 642 * We just write new entry. 643 */ 644 last->e_name_index = index; 645 last->e_name_len = len; 646 memcpy(last->e_name, name, len); 647 pval = last->e_name + len; 648 memcpy(pval, value, size); 649 last->e_value_size = cpu_to_le16(size); 650 new_hsize += newsize; 651 } 652 653 error = write_all_xattrs(inode, new_hsize, base_addr, ipage); 654 if (error) 655 goto exit; 656 657 if (is_inode_flag_set(inode, FI_ACL_MODE)) { 658 inode->i_mode = F2FS_I(inode)->i_acl_mode; 659 inode->i_ctime = current_time(inode); 660 clear_inode_flag(inode, FI_ACL_MODE); 661 } 662 if (index == F2FS_XATTR_INDEX_ENCRYPTION && 663 !strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT)) 664 f2fs_set_encrypted_inode(inode); 665 f2fs_mark_inode_dirty_sync(inode, true); 666 if (!error && S_ISDIR(inode->i_mode)) 667 set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP); 668 exit: 669 kzfree(base_addr); 670 return error; 671 } 672 673 int f2fs_setxattr(struct inode *inode, int index, const char *name, 674 const void *value, size_t size, 675 struct page *ipage, int flags) 676 { 677 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 678 int err; 679 680 /* this case is only from init_inode_metadata */ 681 if (ipage) 682 return __f2fs_setxattr(inode, index, name, value, 683 size, ipage, flags); 684 f2fs_balance_fs(sbi, true); 685 686 f2fs_lock_op(sbi); 687 /* protect xattr_ver */ 688 down_write(&F2FS_I(inode)->i_sem); 689 err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags); 690 up_write(&F2FS_I(inode)->i_sem); 691 f2fs_unlock_op(sbi); 692 693 f2fs_update_time(sbi, REQ_TIME); 694 return err; 695 } 696