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(struct inode *inode, 221 void *base_addr, void **last_addr, int index, 222 size_t len, const char *name) 223 { 224 struct f2fs_xattr_entry *entry; 225 unsigned int inline_size = inline_xattr_size(inode); 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 read_inline_xattr(struct inode *inode, struct page *ipage, 245 void *txattr_addr) 246 { 247 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 248 unsigned int inline_size = inline_xattr_size(inode); 249 struct page *page = NULL; 250 void *inline_addr; 251 252 if (ipage) { 253 inline_addr = inline_xattr_addr(inode, ipage); 254 } else { 255 page = get_node_page(sbi, inode->i_ino); 256 if (IS_ERR(page)) 257 return PTR_ERR(page); 258 259 inline_addr = inline_xattr_addr(inode, page); 260 } 261 memcpy(txattr_addr, inline_addr, inline_size); 262 f2fs_put_page(page, 1); 263 264 return 0; 265 } 266 267 static int read_xattr_block(struct inode *inode, void *txattr_addr) 268 { 269 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 270 nid_t xnid = F2FS_I(inode)->i_xattr_nid; 271 unsigned int inline_size = inline_xattr_size(inode); 272 struct page *xpage; 273 void *xattr_addr; 274 275 /* The inode already has an extended attribute block. */ 276 xpage = get_node_page(sbi, xnid); 277 if (IS_ERR(xpage)) 278 return PTR_ERR(xpage); 279 280 xattr_addr = page_address(xpage); 281 memcpy(txattr_addr + inline_size, xattr_addr, VALID_XATTR_BLOCK_SIZE); 282 f2fs_put_page(xpage, 1); 283 284 return 0; 285 } 286 287 static int lookup_all_xattrs(struct inode *inode, struct page *ipage, 288 unsigned int index, unsigned int len, 289 const char *name, struct f2fs_xattr_entry **xe, 290 void **base_addr) 291 { 292 void *cur_addr, *txattr_addr, *last_addr = NULL; 293 nid_t xnid = F2FS_I(inode)->i_xattr_nid; 294 unsigned int size = xnid ? VALID_XATTR_BLOCK_SIZE : 0; 295 unsigned int inline_size = inline_xattr_size(inode); 296 int err = 0; 297 298 if (!size && !inline_size) 299 return -ENODATA; 300 301 txattr_addr = kzalloc(inline_size + size + XATTR_PADDING_SIZE, 302 GFP_F2FS_ZERO); 303 if (!txattr_addr) 304 return -ENOMEM; 305 306 /* read from inline xattr */ 307 if (inline_size) { 308 err = read_inline_xattr(inode, ipage, txattr_addr); 309 if (err) 310 goto out; 311 312 *xe = __find_inline_xattr(inode, txattr_addr, &last_addr, 313 index, len, name); 314 if (*xe) 315 goto check; 316 } 317 318 /* read from xattr node block */ 319 if (xnid) { 320 err = read_xattr_block(inode, txattr_addr); 321 if (err) 322 goto out; 323 } 324 325 if (last_addr) 326 cur_addr = XATTR_HDR(last_addr) - 1; 327 else 328 cur_addr = txattr_addr; 329 330 *xe = __find_xattr(cur_addr, index, len, name); 331 check: 332 if (IS_XATTR_LAST_ENTRY(*xe)) { 333 err = -ENODATA; 334 goto out; 335 } 336 337 *base_addr = txattr_addr; 338 return 0; 339 out: 340 kzfree(txattr_addr); 341 return err; 342 } 343 344 static int read_all_xattrs(struct inode *inode, struct page *ipage, 345 void **base_addr) 346 { 347 struct f2fs_xattr_header *header; 348 nid_t xnid = F2FS_I(inode)->i_xattr_nid; 349 unsigned int size = VALID_XATTR_BLOCK_SIZE; 350 unsigned int inline_size = inline_xattr_size(inode); 351 void *txattr_addr; 352 int err; 353 354 txattr_addr = kzalloc(inline_size + size + XATTR_PADDING_SIZE, 355 GFP_F2FS_ZERO); 356 if (!txattr_addr) 357 return -ENOMEM; 358 359 /* read from inline xattr */ 360 if (inline_size) { 361 err = read_inline_xattr(inode, ipage, txattr_addr); 362 if (err) 363 goto fail; 364 } 365 366 /* read from xattr node block */ 367 if (xnid) { 368 err = read_xattr_block(inode, txattr_addr); 369 if (err) 370 goto fail; 371 } 372 373 header = XATTR_HDR(txattr_addr); 374 375 /* never been allocated xattrs */ 376 if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) { 377 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC); 378 header->h_refcount = cpu_to_le32(1); 379 } 380 *base_addr = txattr_addr; 381 return 0; 382 fail: 383 kzfree(txattr_addr); 384 return err; 385 } 386 387 static inline int write_all_xattrs(struct inode *inode, __u32 hsize, 388 void *txattr_addr, struct page *ipage) 389 { 390 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 391 size_t inline_size = inline_xattr_size(inode); 392 struct page *in_page = NULL; 393 void *xattr_addr; 394 void *inline_addr = NULL; 395 struct page *xpage; 396 nid_t new_nid = 0; 397 int err = 0; 398 399 if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid) 400 if (!alloc_nid(sbi, &new_nid)) 401 return -ENOSPC; 402 403 /* write to inline xattr */ 404 if (inline_size) { 405 if (ipage) { 406 inline_addr = inline_xattr_addr(inode, ipage); 407 } else { 408 in_page = get_node_page(sbi, inode->i_ino); 409 if (IS_ERR(in_page)) { 410 alloc_nid_failed(sbi, new_nid); 411 return PTR_ERR(in_page); 412 } 413 inline_addr = inline_xattr_addr(inode, in_page); 414 } 415 416 f2fs_wait_on_page_writeback(ipage ? ipage : in_page, 417 NODE, true); 418 /* no need to use xattr node block */ 419 if (hsize <= inline_size) { 420 err = truncate_xattr_node(inode); 421 alloc_nid_failed(sbi, new_nid); 422 if (err) { 423 f2fs_put_page(in_page, 1); 424 return err; 425 } 426 memcpy(inline_addr, txattr_addr, inline_size); 427 set_page_dirty(ipage ? ipage : in_page); 428 goto in_page_out; 429 } 430 } 431 432 /* write to xattr node block */ 433 if (F2FS_I(inode)->i_xattr_nid) { 434 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 435 if (IS_ERR(xpage)) { 436 alloc_nid_failed(sbi, new_nid); 437 goto in_page_out; 438 } 439 f2fs_bug_on(sbi, new_nid); 440 f2fs_wait_on_page_writeback(xpage, NODE, true); 441 } else { 442 struct dnode_of_data dn; 443 set_new_dnode(&dn, inode, NULL, NULL, new_nid); 444 xpage = new_node_page(&dn, XATTR_NODE_OFFSET); 445 if (IS_ERR(xpage)) { 446 alloc_nid_failed(sbi, new_nid); 447 goto in_page_out; 448 } 449 alloc_nid_done(sbi, new_nid); 450 } 451 xattr_addr = page_address(xpage); 452 453 if (inline_size) 454 memcpy(inline_addr, txattr_addr, inline_size); 455 memcpy(xattr_addr, txattr_addr + inline_size, VALID_XATTR_BLOCK_SIZE); 456 457 if (inline_size) 458 set_page_dirty(ipage ? ipage : in_page); 459 set_page_dirty(xpage); 460 461 f2fs_put_page(xpage, 1); 462 in_page_out: 463 f2fs_put_page(in_page, 1); 464 return err; 465 } 466 467 int f2fs_getxattr(struct inode *inode, int index, const char *name, 468 void *buffer, size_t buffer_size, struct page *ipage) 469 { 470 struct f2fs_xattr_entry *entry = NULL; 471 int error = 0; 472 unsigned int size, len; 473 void *base_addr = NULL; 474 475 if (name == NULL) 476 return -EINVAL; 477 478 len = strlen(name); 479 if (len > F2FS_NAME_LEN) 480 return -ERANGE; 481 482 down_read(&F2FS_I(inode)->i_xattr_sem); 483 error = lookup_all_xattrs(inode, ipage, index, len, name, 484 &entry, &base_addr); 485 up_read(&F2FS_I(inode)->i_xattr_sem); 486 if (error) 487 return error; 488 489 size = le16_to_cpu(entry->e_value_size); 490 491 if (buffer && size > buffer_size) { 492 error = -ERANGE; 493 goto out; 494 } 495 496 if (buffer) { 497 char *pval = entry->e_name + entry->e_name_len; 498 memcpy(buffer, pval, size); 499 } 500 error = size; 501 out: 502 kzfree(base_addr); 503 return error; 504 } 505 506 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 507 { 508 struct inode *inode = d_inode(dentry); 509 struct f2fs_xattr_entry *entry; 510 void *base_addr; 511 int error = 0; 512 size_t rest = buffer_size; 513 514 down_read(&F2FS_I(inode)->i_xattr_sem); 515 error = read_all_xattrs(inode, NULL, &base_addr); 516 up_read(&F2FS_I(inode)->i_xattr_sem); 517 if (error) 518 return error; 519 520 list_for_each_xattr(entry, base_addr) { 521 const struct xattr_handler *handler = 522 f2fs_xattr_handler(entry->e_name_index); 523 const char *prefix; 524 size_t prefix_len; 525 size_t size; 526 527 if (!handler || (handler->list && !handler->list(dentry))) 528 continue; 529 530 prefix = handler->prefix ?: handler->name; 531 prefix_len = strlen(prefix); 532 size = prefix_len + entry->e_name_len + 1; 533 if (buffer) { 534 if (size > rest) { 535 error = -ERANGE; 536 goto cleanup; 537 } 538 memcpy(buffer, prefix, prefix_len); 539 buffer += prefix_len; 540 memcpy(buffer, entry->e_name, entry->e_name_len); 541 buffer += entry->e_name_len; 542 *buffer++ = 0; 543 } 544 rest -= size; 545 } 546 error = buffer_size - rest; 547 cleanup: 548 kzfree(base_addr); 549 return error; 550 } 551 552 static bool f2fs_xattr_value_same(struct f2fs_xattr_entry *entry, 553 const void *value, size_t size) 554 { 555 void *pval = entry->e_name + entry->e_name_len; 556 557 return (le16_to_cpu(entry->e_value_size) == size) && 558 !memcmp(pval, value, size); 559 } 560 561 static int __f2fs_setxattr(struct inode *inode, int index, 562 const char *name, const void *value, size_t size, 563 struct page *ipage, int flags) 564 { 565 struct f2fs_xattr_entry *here, *last; 566 void *base_addr; 567 int found, newsize; 568 size_t len; 569 __u32 new_hsize; 570 int error = 0; 571 572 if (name == NULL) 573 return -EINVAL; 574 575 if (value == NULL) 576 size = 0; 577 578 len = strlen(name); 579 580 if (len > F2FS_NAME_LEN) 581 return -ERANGE; 582 583 if (size > MAX_VALUE_LEN(inode)) 584 return -E2BIG; 585 586 error = read_all_xattrs(inode, ipage, &base_addr); 587 if (error) 588 return error; 589 590 /* find entry with wanted name. */ 591 here = __find_xattr(base_addr, index, len, name); 592 593 found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1; 594 595 if (found) { 596 if ((flags & XATTR_CREATE)) { 597 error = -EEXIST; 598 goto exit; 599 } 600 601 if (f2fs_xattr_value_same(here, value, size)) 602 goto exit; 603 } else if ((flags & XATTR_REPLACE)) { 604 error = -ENODATA; 605 goto exit; 606 } 607 608 last = here; 609 while (!IS_XATTR_LAST_ENTRY(last)) 610 last = XATTR_NEXT_ENTRY(last); 611 612 newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size); 613 614 /* 1. Check space */ 615 if (value) { 616 int free; 617 /* 618 * If value is NULL, it is remove operation. 619 * In case of update operation, we calculate free. 620 */ 621 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr); 622 if (found) 623 free = free + ENTRY_SIZE(here); 624 625 if (unlikely(free < newsize)) { 626 error = -E2BIG; 627 goto exit; 628 } 629 } 630 631 /* 2. Remove old entry */ 632 if (found) { 633 /* 634 * If entry is found, remove old entry. 635 * If not found, remove operation is not needed. 636 */ 637 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here); 638 int oldsize = ENTRY_SIZE(here); 639 640 memmove(here, next, (char *)last - (char *)next); 641 last = (struct f2fs_xattr_entry *)((char *)last - oldsize); 642 memset(last, 0, oldsize); 643 } 644 645 new_hsize = (char *)last - (char *)base_addr; 646 647 /* 3. Write new entry */ 648 if (value) { 649 char *pval; 650 /* 651 * Before we come here, old entry is removed. 652 * We just write new entry. 653 */ 654 last->e_name_index = index; 655 last->e_name_len = len; 656 memcpy(last->e_name, name, len); 657 pval = last->e_name + len; 658 memcpy(pval, value, size); 659 last->e_value_size = cpu_to_le16(size); 660 new_hsize += newsize; 661 } 662 663 error = write_all_xattrs(inode, new_hsize, base_addr, ipage); 664 if (error) 665 goto exit; 666 667 if (is_inode_flag_set(inode, FI_ACL_MODE)) { 668 inode->i_mode = F2FS_I(inode)->i_acl_mode; 669 inode->i_ctime = current_time(inode); 670 clear_inode_flag(inode, FI_ACL_MODE); 671 } 672 if (index == F2FS_XATTR_INDEX_ENCRYPTION && 673 !strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT)) 674 f2fs_set_encrypted_inode(inode); 675 f2fs_mark_inode_dirty_sync(inode, true); 676 if (!error && S_ISDIR(inode->i_mode)) 677 set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP); 678 exit: 679 kzfree(base_addr); 680 return error; 681 } 682 683 int f2fs_setxattr(struct inode *inode, int index, const char *name, 684 const void *value, size_t size, 685 struct page *ipage, int flags) 686 { 687 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 688 int err; 689 690 err = dquot_initialize(inode); 691 if (err) 692 return err; 693 694 /* this case is only from init_inode_metadata */ 695 if (ipage) 696 return __f2fs_setxattr(inode, index, name, value, 697 size, ipage, flags); 698 f2fs_balance_fs(sbi, true); 699 700 f2fs_lock_op(sbi); 701 /* protect xattr_ver */ 702 down_write(&F2FS_I(inode)->i_sem); 703 down_write(&F2FS_I(inode)->i_xattr_sem); 704 err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags); 705 up_write(&F2FS_I(inode)->i_xattr_sem); 706 up_write(&F2FS_I(inode)->i_sem); 707 f2fs_unlock_op(sbi); 708 709 f2fs_update_time(sbi, REQ_TIME); 710 return err; 711 } 712