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 = 0; 254 int err = 0; 255 256 inline_size = inline_xattr_size(inode); 257 258 if (!size && !inline_size) 259 return -ENODATA; 260 261 txattr_addr = kzalloc(inline_size + size + sizeof(__u32), 262 GFP_F2FS_ZERO); 263 if (!txattr_addr) 264 return -ENOMEM; 265 266 /* read from inline xattr */ 267 if (inline_size) { 268 struct page *page = NULL; 269 void *inline_addr; 270 271 if (ipage) { 272 inline_addr = inline_xattr_addr(ipage); 273 } else { 274 page = get_node_page(sbi, inode->i_ino); 275 if (IS_ERR(page)) { 276 err = PTR_ERR(page); 277 goto out; 278 } 279 inline_addr = inline_xattr_addr(page); 280 } 281 memcpy(txattr_addr, inline_addr, inline_size); 282 f2fs_put_page(page, 1); 283 284 *xe = __find_inline_xattr(txattr_addr, &last_addr, 285 index, len, name); 286 if (*xe) 287 goto check; 288 } 289 290 /* read from xattr node block */ 291 if (xnid) { 292 struct page *xpage; 293 void *xattr_addr; 294 295 /* The inode already has an extended attribute block. */ 296 xpage = get_node_page(sbi, xnid); 297 if (IS_ERR(xpage)) { 298 err = PTR_ERR(xpage); 299 goto out; 300 } 301 302 xattr_addr = page_address(xpage); 303 memcpy(txattr_addr + inline_size, xattr_addr, size); 304 f2fs_put_page(xpage, 1); 305 } 306 307 if (last_addr) 308 cur_addr = XATTR_HDR(last_addr) - 1; 309 else 310 cur_addr = txattr_addr; 311 312 *xe = __find_xattr(cur_addr, index, len, name); 313 check: 314 if (IS_XATTR_LAST_ENTRY(*xe)) { 315 err = -ENODATA; 316 goto out; 317 } 318 319 *base_addr = txattr_addr; 320 return 0; 321 out: 322 kzfree(txattr_addr); 323 return err; 324 } 325 326 static int read_all_xattrs(struct inode *inode, struct page *ipage, 327 void **base_addr) 328 { 329 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 330 struct f2fs_xattr_header *header; 331 size_t size = PAGE_SIZE, inline_size = 0; 332 void *txattr_addr; 333 int err; 334 335 inline_size = inline_xattr_size(inode); 336 337 txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO); 338 if (!txattr_addr) 339 return -ENOMEM; 340 341 /* read from inline xattr */ 342 if (inline_size) { 343 struct page *page = NULL; 344 void *inline_addr; 345 346 if (ipage) { 347 inline_addr = inline_xattr_addr(ipage); 348 } else { 349 page = get_node_page(sbi, inode->i_ino); 350 if (IS_ERR(page)) { 351 err = PTR_ERR(page); 352 goto fail; 353 } 354 inline_addr = inline_xattr_addr(page); 355 } 356 memcpy(txattr_addr, inline_addr, inline_size); 357 f2fs_put_page(page, 1); 358 } 359 360 /* read from xattr node block */ 361 if (F2FS_I(inode)->i_xattr_nid) { 362 struct page *xpage; 363 void *xattr_addr; 364 365 /* The inode already has an extended attribute block. */ 366 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 367 if (IS_ERR(xpage)) { 368 err = PTR_ERR(xpage); 369 goto fail; 370 } 371 372 xattr_addr = page_address(xpage); 373 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE); 374 f2fs_put_page(xpage, 1); 375 } 376 377 header = XATTR_HDR(txattr_addr); 378 379 /* never been allocated xattrs */ 380 if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) { 381 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC); 382 header->h_refcount = cpu_to_le32(1); 383 } 384 *base_addr = txattr_addr; 385 return 0; 386 fail: 387 kzfree(txattr_addr); 388 return err; 389 } 390 391 static inline int write_all_xattrs(struct inode *inode, __u32 hsize, 392 void *txattr_addr, struct page *ipage) 393 { 394 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 395 size_t inline_size = 0; 396 void *xattr_addr; 397 struct page *xpage; 398 nid_t new_nid = 0; 399 int err; 400 401 inline_size = inline_xattr_size(inode); 402 403 if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid) 404 if (!alloc_nid(sbi, &new_nid)) 405 return -ENOSPC; 406 407 /* write to inline xattr */ 408 if (inline_size) { 409 struct page *page = NULL; 410 void *inline_addr; 411 412 if (ipage) { 413 inline_addr = inline_xattr_addr(ipage); 414 f2fs_wait_on_page_writeback(ipage, NODE, true); 415 set_page_dirty(ipage); 416 } else { 417 page = get_node_page(sbi, inode->i_ino); 418 if (IS_ERR(page)) { 419 alloc_nid_failed(sbi, new_nid); 420 return PTR_ERR(page); 421 } 422 inline_addr = inline_xattr_addr(page); 423 f2fs_wait_on_page_writeback(page, NODE, true); 424 } 425 memcpy(inline_addr, txattr_addr, inline_size); 426 f2fs_put_page(page, 1); 427 428 /* no need to use xattr node block */ 429 if (hsize <= inline_size) { 430 err = truncate_xattr_node(inode, ipage); 431 alloc_nid_failed(sbi, new_nid); 432 return err; 433 } 434 } 435 436 /* write to xattr node block */ 437 if (F2FS_I(inode)->i_xattr_nid) { 438 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 439 if (IS_ERR(xpage)) { 440 alloc_nid_failed(sbi, new_nid); 441 return PTR_ERR(xpage); 442 } 443 f2fs_bug_on(sbi, new_nid); 444 f2fs_wait_on_page_writeback(xpage, NODE, true); 445 } else { 446 struct dnode_of_data dn; 447 set_new_dnode(&dn, inode, NULL, NULL, new_nid); 448 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage); 449 if (IS_ERR(xpage)) { 450 alloc_nid_failed(sbi, new_nid); 451 return PTR_ERR(xpage); 452 } 453 alloc_nid_done(sbi, new_nid); 454 } 455 456 xattr_addr = page_address(xpage); 457 memcpy(xattr_addr, txattr_addr + inline_size, MAX_XATTR_BLOCK_SIZE); 458 set_page_dirty(xpage); 459 f2fs_put_page(xpage, 1); 460 461 return 0; 462 } 463 464 int f2fs_getxattr(struct inode *inode, int index, const char *name, 465 void *buffer, size_t buffer_size, struct page *ipage) 466 { 467 struct f2fs_xattr_entry *entry = NULL; 468 int error = 0; 469 unsigned int size, len; 470 void *base_addr = NULL; 471 472 if (name == NULL) 473 return -EINVAL; 474 475 len = strlen(name); 476 if (len > F2FS_NAME_LEN) 477 return -ERANGE; 478 479 error = lookup_all_xattrs(inode, ipage, index, len, name, 480 &entry, &base_addr); 481 if (error) 482 return error; 483 484 size = le16_to_cpu(entry->e_value_size); 485 486 if (buffer && size > buffer_size) { 487 error = -ERANGE; 488 goto out; 489 } 490 491 if (buffer) { 492 char *pval = entry->e_name + entry->e_name_len; 493 memcpy(buffer, pval, size); 494 } 495 error = size; 496 out: 497 kzfree(base_addr); 498 return error; 499 } 500 501 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 502 { 503 struct inode *inode = d_inode(dentry); 504 struct f2fs_xattr_entry *entry; 505 void *base_addr; 506 int error = 0; 507 size_t rest = buffer_size; 508 509 error = read_all_xattrs(inode, NULL, &base_addr); 510 if (error) 511 return error; 512 513 list_for_each_xattr(entry, base_addr) { 514 const struct xattr_handler *handler = 515 f2fs_xattr_handler(entry->e_name_index); 516 const char *prefix; 517 size_t prefix_len; 518 size_t size; 519 520 if (!handler || (handler->list && !handler->list(dentry))) 521 continue; 522 523 prefix = handler->prefix ?: handler->name; 524 prefix_len = strlen(prefix); 525 size = prefix_len + entry->e_name_len + 1; 526 if (buffer) { 527 if (size > rest) { 528 error = -ERANGE; 529 goto cleanup; 530 } 531 memcpy(buffer, prefix, prefix_len); 532 buffer += prefix_len; 533 memcpy(buffer, entry->e_name, entry->e_name_len); 534 buffer += entry->e_name_len; 535 *buffer++ = 0; 536 } 537 rest -= size; 538 } 539 error = buffer_size - rest; 540 cleanup: 541 kzfree(base_addr); 542 return error; 543 } 544 545 static bool f2fs_xattr_value_same(struct f2fs_xattr_entry *entry, 546 const void *value, size_t size) 547 { 548 void *pval = entry->e_name + entry->e_name_len; 549 return (entry->e_value_size == size) && !memcmp(pval, value, size); 550 } 551 552 static int __f2fs_setxattr(struct inode *inode, int index, 553 const char *name, const void *value, size_t size, 554 struct page *ipage, int flags) 555 { 556 struct f2fs_xattr_entry *here, *last; 557 void *base_addr; 558 int found, newsize; 559 size_t len; 560 __u32 new_hsize; 561 int error = 0; 562 563 if (name == NULL) 564 return -EINVAL; 565 566 if (value == NULL) 567 size = 0; 568 569 len = strlen(name); 570 571 if (len > F2FS_NAME_LEN) 572 return -ERANGE; 573 574 if (size > MAX_VALUE_LEN(inode)) 575 return -E2BIG; 576 577 error = read_all_xattrs(inode, ipage, &base_addr); 578 if (error) 579 return error; 580 581 /* find entry with wanted name. */ 582 here = __find_xattr(base_addr, index, len, name); 583 584 found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1; 585 586 if (found) { 587 if ((flags & XATTR_CREATE)) { 588 error = -EEXIST; 589 goto exit; 590 } 591 592 if (f2fs_xattr_value_same(here, value, size)) 593 goto exit; 594 } else if ((flags & XATTR_REPLACE)) { 595 error = -ENODATA; 596 goto exit; 597 } 598 599 last = here; 600 while (!IS_XATTR_LAST_ENTRY(last)) 601 last = XATTR_NEXT_ENTRY(last); 602 603 newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size); 604 605 /* 1. Check space */ 606 if (value) { 607 int free; 608 /* 609 * If value is NULL, it is remove operation. 610 * In case of update operation, we calculate free. 611 */ 612 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr); 613 if (found) 614 free = free + ENTRY_SIZE(here); 615 616 if (unlikely(free < newsize)) { 617 error = -E2BIG; 618 goto exit; 619 } 620 } 621 622 /* 2. Remove old entry */ 623 if (found) { 624 /* 625 * If entry is found, remove old entry. 626 * If not found, remove operation is not needed. 627 */ 628 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here); 629 int oldsize = ENTRY_SIZE(here); 630 631 memmove(here, next, (char *)last - (char *)next); 632 last = (struct f2fs_xattr_entry *)((char *)last - oldsize); 633 memset(last, 0, oldsize); 634 } 635 636 new_hsize = (char *)last - (char *)base_addr; 637 638 /* 3. Write new entry */ 639 if (value) { 640 char *pval; 641 /* 642 * Before we come here, old entry is removed. 643 * We just write new entry. 644 */ 645 last->e_name_index = index; 646 last->e_name_len = len; 647 memcpy(last->e_name, name, len); 648 pval = last->e_name + len; 649 memcpy(pval, value, size); 650 last->e_value_size = cpu_to_le16(size); 651 new_hsize += newsize; 652 } 653 654 error = write_all_xattrs(inode, new_hsize, base_addr, ipage); 655 if (error) 656 goto exit; 657 658 if (is_inode_flag_set(inode, FI_ACL_MODE)) { 659 inode->i_mode = F2FS_I(inode)->i_acl_mode; 660 inode->i_ctime = current_time(inode); 661 clear_inode_flag(inode, FI_ACL_MODE); 662 } 663 if (index == F2FS_XATTR_INDEX_ENCRYPTION && 664 !strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT)) 665 f2fs_set_encrypted_inode(inode); 666 f2fs_mark_inode_dirty_sync(inode, true); 667 if (!error && S_ISDIR(inode->i_mode)) 668 set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP); 669 exit: 670 kzfree(base_addr); 671 return error; 672 } 673 674 int f2fs_setxattr(struct inode *inode, int index, const char *name, 675 const void *value, size_t size, 676 struct page *ipage, int flags) 677 { 678 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 679 int err; 680 681 /* this case is only from init_inode_metadata */ 682 if (ipage) 683 return __f2fs_setxattr(inode, index, name, value, 684 size, ipage, flags); 685 f2fs_balance_fs(sbi, true); 686 687 f2fs_lock_op(sbi); 688 /* protect xattr_ver */ 689 down_write(&F2FS_I(inode)->i_sem); 690 err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags); 691 up_write(&F2FS_I(inode)->i_sem); 692 f2fs_unlock_op(sbi); 693 694 f2fs_update_time(sbi, REQ_TIME); 695 return err; 696 } 697