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 size_t f2fs_xattr_generic_list(struct dentry *dentry, char *list, 29 size_t list_size, const char *name, size_t 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 + len + 1; 57 if (list && total_len <= list_size) { 58 memcpy(list, prefix, prefix_len); 59 memcpy(list + prefix_len, name, len); 60 list[prefix_len + len] = '\0'; 61 } 62 return total_len; 63 } 64 65 static 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(d_inode(dentry), type, name, buffer, size, NULL); 87 } 88 89 static 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(d_inode(dentry), type, name, 112 value, size, NULL, flags); 113 } 114 115 static size_t f2fs_xattr_advise_list(struct dentry *dentry, char *list, 116 size_t list_size, const char *name, size_t len, int type) 117 { 118 const char *xname = F2FS_SYSTEM_ADVISE_PREFIX; 119 size_t size; 120 121 if (type != F2FS_XATTR_INDEX_ADVISE) 122 return 0; 123 124 size = strlen(xname) + 1; 125 if (list && size <= list_size) 126 memcpy(list, xname, size); 127 return size; 128 } 129 130 static int f2fs_xattr_advise_get(struct dentry *dentry, const char *name, 131 void *buffer, size_t size, int type) 132 { 133 struct inode *inode = d_inode(dentry); 134 135 if (strcmp(name, "") != 0) 136 return -EINVAL; 137 138 if (buffer) 139 *((char *)buffer) = F2FS_I(inode)->i_advise; 140 return sizeof(char); 141 } 142 143 static int f2fs_xattr_advise_set(struct dentry *dentry, const char *name, 144 const void *value, size_t size, int flags, int type) 145 { 146 struct inode *inode = d_inode(dentry); 147 148 if (strcmp(name, "") != 0) 149 return -EINVAL; 150 if (!inode_owner_or_capable(inode)) 151 return -EPERM; 152 if (value == NULL) 153 return -EINVAL; 154 155 F2FS_I(inode)->i_advise |= *(char *)value; 156 mark_inode_dirty(inode); 157 return 0; 158 } 159 160 #ifdef CONFIG_F2FS_FS_SECURITY 161 static 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, 0); 171 if (err < 0) 172 break; 173 } 174 return err; 175 } 176 177 int 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 184 185 const 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 }; 192 193 const 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 }; 200 201 const 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 }; 208 209 const 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 }; 216 217 static 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 }; 229 230 const 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 }; 243 244 static inline const struct xattr_handler *f2fs_xattr_handler(int index) 245 { 246 const struct xattr_handler *handler = NULL; 247 248 if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map)) 249 handler = f2fs_xattr_handler_map[index]; 250 return handler; 251 } 252 253 static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int index, 254 size_t 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 != index) 260 continue; 261 if (entry->e_name_len != len) 262 continue; 263 if (!memcmp(entry->e_name, name, len)) 264 break; 265 } 266 return entry; 267 } 268 269 static void *read_all_xattrs(struct inode *inode, struct page *ipage) 270 { 271 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 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; 322 fail: 323 kzfree(txattr_addr); 324 return NULL; 325 } 326 327 static 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_I_SB(inode); 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 f2fs_wait_on_page_writeback(ipage, NODE); 351 } else { 352 page = get_node_page(sbi, inode->i_ino); 353 if (IS_ERR(page)) { 354 alloc_nid_failed(sbi, new_nid); 355 return PTR_ERR(page); 356 } 357 inline_addr = inline_xattr_addr(page); 358 f2fs_wait_on_page_writeback(page, NODE); 359 } 360 memcpy(inline_addr, txattr_addr, inline_size); 361 f2fs_put_page(page, 1); 362 363 /* no need to use xattr node block */ 364 if (hsize <= inline_size) { 365 err = truncate_xattr_node(inode, ipage); 366 alloc_nid_failed(sbi, new_nid); 367 return err; 368 } 369 } 370 371 /* write to xattr node block */ 372 if (F2FS_I(inode)->i_xattr_nid) { 373 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 374 if (IS_ERR(xpage)) { 375 alloc_nid_failed(sbi, new_nid); 376 return PTR_ERR(xpage); 377 } 378 f2fs_bug_on(sbi, new_nid); 379 f2fs_wait_on_page_writeback(xpage, NODE); 380 } else { 381 struct dnode_of_data dn; 382 set_new_dnode(&dn, inode, NULL, NULL, new_nid); 383 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage); 384 if (IS_ERR(xpage)) { 385 alloc_nid_failed(sbi, new_nid); 386 return PTR_ERR(xpage); 387 } 388 alloc_nid_done(sbi, new_nid); 389 } 390 391 xattr_addr = page_address(xpage); 392 memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE - 393 sizeof(struct node_footer)); 394 set_page_dirty(xpage); 395 f2fs_put_page(xpage, 1); 396 397 /* need to checkpoint during fsync */ 398 F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi)); 399 return 0; 400 } 401 402 int f2fs_getxattr(struct inode *inode, int index, const char *name, 403 void *buffer, size_t buffer_size, struct page *ipage) 404 { 405 struct f2fs_xattr_entry *entry; 406 void *base_addr; 407 int error = 0; 408 size_t size, len; 409 410 if (name == NULL) 411 return -EINVAL; 412 413 len = strlen(name); 414 if (len > F2FS_NAME_LEN) 415 return -ERANGE; 416 417 base_addr = read_all_xattrs(inode, ipage); 418 if (!base_addr) 419 return -ENOMEM; 420 421 entry = __find_xattr(base_addr, index, len, name); 422 if (IS_XATTR_LAST_ENTRY(entry)) { 423 error = -ENODATA; 424 goto cleanup; 425 } 426 427 size = le16_to_cpu(entry->e_value_size); 428 429 if (buffer && size > buffer_size) { 430 error = -ERANGE; 431 goto cleanup; 432 } 433 434 if (buffer) { 435 char *pval = entry->e_name + entry->e_name_len; 436 memcpy(buffer, pval, size); 437 } 438 error = size; 439 440 cleanup: 441 kzfree(base_addr); 442 return error; 443 } 444 445 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 446 { 447 struct inode *inode = d_inode(dentry); 448 struct f2fs_xattr_entry *entry; 449 void *base_addr; 450 int error = 0; 451 size_t rest = buffer_size; 452 453 base_addr = read_all_xattrs(inode, NULL); 454 if (!base_addr) 455 return -ENOMEM; 456 457 list_for_each_xattr(entry, base_addr) { 458 const struct xattr_handler *handler = 459 f2fs_xattr_handler(entry->e_name_index); 460 size_t size; 461 462 if (!handler) 463 continue; 464 465 size = handler->list(dentry, buffer, rest, entry->e_name, 466 entry->e_name_len, handler->flags); 467 if (buffer && size > rest) { 468 error = -ERANGE; 469 goto cleanup; 470 } 471 472 if (buffer) 473 buffer += size; 474 rest -= size; 475 } 476 error = buffer_size - rest; 477 cleanup: 478 kzfree(base_addr); 479 return error; 480 } 481 482 static int __f2fs_setxattr(struct inode *inode, int index, 483 const char *name, const void *value, size_t size, 484 struct page *ipage, int flags) 485 { 486 struct f2fs_inode_info *fi = F2FS_I(inode); 487 struct f2fs_xattr_entry *here, *last; 488 void *base_addr; 489 int found, newsize; 490 size_t len; 491 __u32 new_hsize; 492 int error = -ENOMEM; 493 494 if (name == NULL) 495 return -EINVAL; 496 497 if (value == NULL) 498 size = 0; 499 500 len = strlen(name); 501 502 if (len > F2FS_NAME_LEN) 503 return -ERANGE; 504 505 if (size > MAX_VALUE_LEN(inode)) 506 return -E2BIG; 507 508 base_addr = read_all_xattrs(inode, ipage); 509 if (!base_addr) 510 goto exit; 511 512 /* find entry with wanted name. */ 513 here = __find_xattr(base_addr, index, len, name); 514 515 found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1; 516 517 if ((flags & XATTR_REPLACE) && !found) { 518 error = -ENODATA; 519 goto exit; 520 } else if ((flags & XATTR_CREATE) && found) { 521 error = -EEXIST; 522 goto exit; 523 } 524 525 last = here; 526 while (!IS_XATTR_LAST_ENTRY(last)) 527 last = XATTR_NEXT_ENTRY(last); 528 529 newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size); 530 531 /* 1. Check space */ 532 if (value) { 533 int free; 534 /* 535 * If value is NULL, it is remove operation. 536 * In case of update operation, we calculate free. 537 */ 538 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr); 539 if (found) 540 free = free + ENTRY_SIZE(here); 541 542 if (unlikely(free < newsize)) { 543 error = -ENOSPC; 544 goto exit; 545 } 546 } 547 548 /* 2. Remove old entry */ 549 if (found) { 550 /* 551 * If entry is found, remove old entry. 552 * If not found, remove operation is not needed. 553 */ 554 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here); 555 int oldsize = ENTRY_SIZE(here); 556 557 memmove(here, next, (char *)last - (char *)next); 558 last = (struct f2fs_xattr_entry *)((char *)last - oldsize); 559 memset(last, 0, oldsize); 560 } 561 562 new_hsize = (char *)last - (char *)base_addr; 563 564 /* 3. Write new entry */ 565 if (value) { 566 char *pval; 567 /* 568 * Before we come here, old entry is removed. 569 * We just write new entry. 570 */ 571 memset(last, 0, newsize); 572 last->e_name_index = index; 573 last->e_name_len = len; 574 memcpy(last->e_name, name, len); 575 pval = last->e_name + len; 576 memcpy(pval, value, size); 577 last->e_value_size = cpu_to_le16(size); 578 new_hsize += newsize; 579 } 580 581 error = write_all_xattrs(inode, new_hsize, base_addr, ipage); 582 if (error) 583 goto exit; 584 585 if (is_inode_flag_set(fi, FI_ACL_MODE)) { 586 inode->i_mode = fi->i_acl_mode; 587 inode->i_ctime = CURRENT_TIME; 588 clear_inode_flag(fi, FI_ACL_MODE); 589 } 590 if (index == F2FS_XATTR_INDEX_ENCRYPTION && 591 !strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT)) 592 f2fs_set_encrypted_inode(inode); 593 594 if (ipage) 595 update_inode(inode, ipage); 596 else 597 update_inode_page(inode); 598 exit: 599 kzfree(base_addr); 600 return error; 601 } 602 603 int f2fs_setxattr(struct inode *inode, int index, const char *name, 604 const void *value, size_t size, 605 struct page *ipage, int flags) 606 { 607 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 608 int err; 609 610 /* this case is only from init_inode_metadata */ 611 if (ipage) 612 return __f2fs_setxattr(inode, index, name, value, 613 size, ipage, flags); 614 f2fs_balance_fs(sbi); 615 616 f2fs_lock_op(sbi); 617 /* protect xattr_ver */ 618 down_write(&F2FS_I(inode)->i_sem); 619 err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags); 620 up_write(&F2FS_I(inode)->i_sem); 621 f2fs_unlock_op(sbi); 622 623 return err; 624 } 625