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(const struct xattr_handler *handler, 29 struct dentry *dentry, char *list, size_t list_size, 30 const char *name, size_t len) 31 { 32 struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb); 33 int total_len, prefix_len; 34 35 switch (handler->flags) { 36 case F2FS_XATTR_INDEX_USER: 37 if (!test_opt(sbi, XATTR_USER)) 38 return -EOPNOTSUPP; 39 break; 40 case F2FS_XATTR_INDEX_TRUSTED: 41 if (!capable(CAP_SYS_ADMIN)) 42 return -EPERM; 43 break; 44 case F2FS_XATTR_INDEX_SECURITY: 45 break; 46 default: 47 return -EINVAL; 48 } 49 50 prefix_len = strlen(handler->prefix); 51 total_len = prefix_len + len + 1; 52 if (list && total_len <= list_size) { 53 memcpy(list, handler->prefix, prefix_len); 54 memcpy(list + prefix_len, name, len); 55 list[prefix_len + len] = '\0'; 56 } 57 return total_len; 58 } 59 60 static int f2fs_xattr_generic_get(const struct xattr_handler *handler, 61 struct dentry *dentry, const char *name, void *buffer, 62 size_t size) 63 { 64 struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb); 65 66 switch (handler->flags) { 67 case F2FS_XATTR_INDEX_USER: 68 if (!test_opt(sbi, XATTR_USER)) 69 return -EOPNOTSUPP; 70 break; 71 case F2FS_XATTR_INDEX_TRUSTED: 72 if (!capable(CAP_SYS_ADMIN)) 73 return -EPERM; 74 break; 75 case F2FS_XATTR_INDEX_SECURITY: 76 break; 77 default: 78 return -EINVAL; 79 } 80 if (strcmp(name, "") == 0) 81 return -EINVAL; 82 return f2fs_getxattr(d_inode(dentry), handler->flags, name, 83 buffer, size, NULL); 84 } 85 86 static int f2fs_xattr_generic_set(const struct xattr_handler *handler, 87 struct dentry *dentry, const char *name, const void *value, 88 size_t size, int flags) 89 { 90 struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb); 91 92 switch (handler->flags) { 93 case F2FS_XATTR_INDEX_USER: 94 if (!test_opt(sbi, XATTR_USER)) 95 return -EOPNOTSUPP; 96 break; 97 case F2FS_XATTR_INDEX_TRUSTED: 98 if (!capable(CAP_SYS_ADMIN)) 99 return -EPERM; 100 break; 101 case F2FS_XATTR_INDEX_SECURITY: 102 break; 103 default: 104 return -EINVAL; 105 } 106 if (strcmp(name, "") == 0) 107 return -EINVAL; 108 109 return f2fs_setxattr(d_inode(dentry), handler->flags, name, 110 value, size, NULL, flags); 111 } 112 113 static size_t f2fs_xattr_advise_list(const struct xattr_handler *handler, 114 struct dentry *dentry, char *list, size_t list_size, 115 const char *name, size_t len) 116 { 117 const char *xname = F2FS_SYSTEM_ADVISE_PREFIX; 118 size_t size; 119 120 size = strlen(xname) + 1; 121 if (list && size <= list_size) 122 memcpy(list, xname, size); 123 return size; 124 } 125 126 static int f2fs_xattr_advise_get(const struct xattr_handler *handler, 127 struct dentry *dentry, const char *name, void *buffer, 128 size_t size) 129 { 130 struct inode *inode = d_inode(dentry); 131 132 if (strcmp(name, "") != 0) 133 return -EINVAL; 134 135 if (buffer) 136 *((char *)buffer) = F2FS_I(inode)->i_advise; 137 return sizeof(char); 138 } 139 140 static int f2fs_xattr_advise_set(const struct xattr_handler *handler, 141 struct dentry *dentry, const char *name, const void *value, 142 size_t size, int flags) 143 { 144 struct inode *inode = d_inode(dentry); 145 146 if (strcmp(name, "") != 0) 147 return -EINVAL; 148 if (!inode_owner_or_capable(inode)) 149 return -EPERM; 150 if (value == NULL) 151 return -EINVAL; 152 153 F2FS_I(inode)->i_advise |= *(char *)value; 154 mark_inode_dirty(inode); 155 return 0; 156 } 157 158 #ifdef CONFIG_F2FS_FS_SECURITY 159 static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array, 160 void *page) 161 { 162 const struct xattr *xattr; 163 int err = 0; 164 165 for (xattr = xattr_array; xattr->name != NULL; xattr++) { 166 err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY, 167 xattr->name, xattr->value, 168 xattr->value_len, (struct page *)page, 0); 169 if (err < 0) 170 break; 171 } 172 return err; 173 } 174 175 int f2fs_init_security(struct inode *inode, struct inode *dir, 176 const struct qstr *qstr, struct page *ipage) 177 { 178 return security_inode_init_security(inode, dir, qstr, 179 &f2fs_initxattrs, ipage); 180 } 181 #endif 182 183 const struct xattr_handler f2fs_xattr_user_handler = { 184 .prefix = XATTR_USER_PREFIX, 185 .flags = F2FS_XATTR_INDEX_USER, 186 .list = f2fs_xattr_generic_list, 187 .get = f2fs_xattr_generic_get, 188 .set = f2fs_xattr_generic_set, 189 }; 190 191 const struct xattr_handler f2fs_xattr_trusted_handler = { 192 .prefix = XATTR_TRUSTED_PREFIX, 193 .flags = F2FS_XATTR_INDEX_TRUSTED, 194 .list = f2fs_xattr_generic_list, 195 .get = f2fs_xattr_generic_get, 196 .set = f2fs_xattr_generic_set, 197 }; 198 199 const struct xattr_handler f2fs_xattr_advise_handler = { 200 .prefix = F2FS_SYSTEM_ADVISE_PREFIX, 201 .flags = F2FS_XATTR_INDEX_ADVISE, 202 .list = f2fs_xattr_advise_list, 203 .get = f2fs_xattr_advise_get, 204 .set = f2fs_xattr_advise_set, 205 }; 206 207 const struct xattr_handler f2fs_xattr_security_handler = { 208 .prefix = XATTR_SECURITY_PREFIX, 209 .flags = F2FS_XATTR_INDEX_SECURITY, 210 .list = f2fs_xattr_generic_list, 211 .get = f2fs_xattr_generic_get, 212 .set = f2fs_xattr_generic_set, 213 }; 214 215 static const struct xattr_handler *f2fs_xattr_handler_map[] = { 216 [F2FS_XATTR_INDEX_USER] = &f2fs_xattr_user_handler, 217 #ifdef CONFIG_F2FS_FS_POSIX_ACL 218 [F2FS_XATTR_INDEX_POSIX_ACL_ACCESS] = &posix_acl_access_xattr_handler, 219 [F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &posix_acl_default_xattr_handler, 220 #endif 221 [F2FS_XATTR_INDEX_TRUSTED] = &f2fs_xattr_trusted_handler, 222 #ifdef CONFIG_F2FS_FS_SECURITY 223 [F2FS_XATTR_INDEX_SECURITY] = &f2fs_xattr_security_handler, 224 #endif 225 [F2FS_XATTR_INDEX_ADVISE] = &f2fs_xattr_advise_handler, 226 }; 227 228 const struct xattr_handler *f2fs_xattr_handlers[] = { 229 &f2fs_xattr_user_handler, 230 #ifdef CONFIG_F2FS_FS_POSIX_ACL 231 &posix_acl_access_xattr_handler, 232 &posix_acl_default_xattr_handler, 233 #endif 234 &f2fs_xattr_trusted_handler, 235 #ifdef CONFIG_F2FS_FS_SECURITY 236 &f2fs_xattr_security_handler, 237 #endif 238 &f2fs_xattr_advise_handler, 239 NULL, 240 }; 241 242 static inline const struct xattr_handler *f2fs_xattr_handler(int index) 243 { 244 const struct xattr_handler *handler = NULL; 245 246 if (index > 0 && index < ARRAY_SIZE(f2fs_xattr_handler_map)) 247 handler = f2fs_xattr_handler_map[index]; 248 return handler; 249 } 250 251 static struct f2fs_xattr_entry *__find_xattr(void *base_addr, int index, 252 size_t len, const char *name) 253 { 254 struct f2fs_xattr_entry *entry; 255 256 list_for_each_xattr(entry, base_addr) { 257 if (entry->e_name_index != index) 258 continue; 259 if (entry->e_name_len != len) 260 continue; 261 if (!memcmp(entry->e_name, name, len)) 262 break; 263 } 264 return entry; 265 } 266 267 static void *read_all_xattrs(struct inode *inode, struct page *ipage) 268 { 269 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 270 struct f2fs_xattr_header *header; 271 size_t size = PAGE_SIZE, inline_size = 0; 272 void *txattr_addr; 273 274 inline_size = inline_xattr_size(inode); 275 276 txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO); 277 if (!txattr_addr) 278 return NULL; 279 280 /* read from inline xattr */ 281 if (inline_size) { 282 struct page *page = NULL; 283 void *inline_addr; 284 285 if (ipage) { 286 inline_addr = inline_xattr_addr(ipage); 287 } else { 288 page = get_node_page(sbi, inode->i_ino); 289 if (IS_ERR(page)) 290 goto fail; 291 inline_addr = inline_xattr_addr(page); 292 } 293 memcpy(txattr_addr, inline_addr, inline_size); 294 f2fs_put_page(page, 1); 295 } 296 297 /* read from xattr node block */ 298 if (F2FS_I(inode)->i_xattr_nid) { 299 struct page *xpage; 300 void *xattr_addr; 301 302 /* The inode already has an extended attribute block. */ 303 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 304 if (IS_ERR(xpage)) 305 goto fail; 306 307 xattr_addr = page_address(xpage); 308 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE); 309 f2fs_put_page(xpage, 1); 310 } 311 312 header = XATTR_HDR(txattr_addr); 313 314 /* never been allocated xattrs */ 315 if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) { 316 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC); 317 header->h_refcount = cpu_to_le32(1); 318 } 319 return txattr_addr; 320 fail: 321 kzfree(txattr_addr); 322 return NULL; 323 } 324 325 static inline int write_all_xattrs(struct inode *inode, __u32 hsize, 326 void *txattr_addr, struct page *ipage) 327 { 328 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 329 size_t inline_size = 0; 330 void *xattr_addr; 331 struct page *xpage; 332 nid_t new_nid = 0; 333 int err; 334 335 inline_size = inline_xattr_size(inode); 336 337 if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid) 338 if (!alloc_nid(sbi, &new_nid)) 339 return -ENOSPC; 340 341 /* write to 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 f2fs_wait_on_page_writeback(ipage, NODE); 349 } else { 350 page = get_node_page(sbi, inode->i_ino); 351 if (IS_ERR(page)) { 352 alloc_nid_failed(sbi, new_nid); 353 return PTR_ERR(page); 354 } 355 inline_addr = inline_xattr_addr(page); 356 f2fs_wait_on_page_writeback(page, NODE); 357 } 358 memcpy(inline_addr, txattr_addr, inline_size); 359 f2fs_put_page(page, 1); 360 361 /* no need to use xattr node block */ 362 if (hsize <= inline_size) { 363 err = truncate_xattr_node(inode, ipage); 364 alloc_nid_failed(sbi, new_nid); 365 return err; 366 } 367 } 368 369 /* write to xattr node block */ 370 if (F2FS_I(inode)->i_xattr_nid) { 371 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 372 if (IS_ERR(xpage)) { 373 alloc_nid_failed(sbi, new_nid); 374 return PTR_ERR(xpage); 375 } 376 f2fs_bug_on(sbi, new_nid); 377 f2fs_wait_on_page_writeback(xpage, NODE); 378 } else { 379 struct dnode_of_data dn; 380 set_new_dnode(&dn, inode, NULL, NULL, new_nid); 381 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage); 382 if (IS_ERR(xpage)) { 383 alloc_nid_failed(sbi, new_nid); 384 return PTR_ERR(xpage); 385 } 386 alloc_nid_done(sbi, new_nid); 387 } 388 389 xattr_addr = page_address(xpage); 390 memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE - 391 sizeof(struct node_footer)); 392 set_page_dirty(xpage); 393 f2fs_put_page(xpage, 1); 394 395 /* need to checkpoint during fsync */ 396 F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi)); 397 return 0; 398 } 399 400 int f2fs_getxattr(struct inode *inode, int index, const char *name, 401 void *buffer, size_t buffer_size, struct page *ipage) 402 { 403 struct f2fs_xattr_entry *entry; 404 void *base_addr; 405 int error = 0; 406 size_t size, len; 407 408 if (name == NULL) 409 return -EINVAL; 410 411 len = strlen(name); 412 if (len > F2FS_NAME_LEN) 413 return -ERANGE; 414 415 base_addr = read_all_xattrs(inode, ipage); 416 if (!base_addr) 417 return -ENOMEM; 418 419 entry = __find_xattr(base_addr, index, len, name); 420 if (IS_XATTR_LAST_ENTRY(entry)) { 421 error = -ENODATA; 422 goto cleanup; 423 } 424 425 size = le16_to_cpu(entry->e_value_size); 426 427 if (buffer && size > buffer_size) { 428 error = -ERANGE; 429 goto cleanup; 430 } 431 432 if (buffer) { 433 char *pval = entry->e_name + entry->e_name_len; 434 memcpy(buffer, pval, size); 435 } 436 error = size; 437 438 cleanup: 439 kzfree(base_addr); 440 return error; 441 } 442 443 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 444 { 445 struct inode *inode = d_inode(dentry); 446 struct f2fs_xattr_entry *entry; 447 void *base_addr; 448 int error = 0; 449 size_t rest = buffer_size; 450 451 base_addr = read_all_xattrs(inode, NULL); 452 if (!base_addr) 453 return -ENOMEM; 454 455 list_for_each_xattr(entry, base_addr) { 456 const struct xattr_handler *handler = 457 f2fs_xattr_handler(entry->e_name_index); 458 size_t size; 459 460 if (!handler) 461 continue; 462 463 size = handler->list(handler, dentry, buffer, rest, 464 entry->e_name, entry->e_name_len); 465 if (buffer && size > rest) { 466 error = -ERANGE; 467 goto cleanup; 468 } 469 470 if (buffer) 471 buffer += size; 472 rest -= size; 473 } 474 error = buffer_size - rest; 475 cleanup: 476 kzfree(base_addr); 477 return error; 478 } 479 480 static int __f2fs_setxattr(struct inode *inode, int index, 481 const char *name, const void *value, size_t size, 482 struct page *ipage, int flags) 483 { 484 struct f2fs_inode_info *fi = F2FS_I(inode); 485 struct f2fs_xattr_entry *here, *last; 486 void *base_addr; 487 int found, newsize; 488 size_t len; 489 __u32 new_hsize; 490 int error = -ENOMEM; 491 492 if (name == NULL) 493 return -EINVAL; 494 495 if (value == NULL) 496 size = 0; 497 498 len = strlen(name); 499 500 if (len > F2FS_NAME_LEN) 501 return -ERANGE; 502 503 if (size > MAX_VALUE_LEN(inode)) 504 return -E2BIG; 505 506 base_addr = read_all_xattrs(inode, ipage); 507 if (!base_addr) 508 goto exit; 509 510 /* find entry with wanted name. */ 511 here = __find_xattr(base_addr, index, len, name); 512 513 found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1; 514 515 if ((flags & XATTR_REPLACE) && !found) { 516 error = -ENODATA; 517 goto exit; 518 } else if ((flags & XATTR_CREATE) && found) { 519 error = -EEXIST; 520 goto exit; 521 } 522 523 last = here; 524 while (!IS_XATTR_LAST_ENTRY(last)) 525 last = XATTR_NEXT_ENTRY(last); 526 527 newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size); 528 529 /* 1. Check space */ 530 if (value) { 531 int free; 532 /* 533 * If value is NULL, it is remove operation. 534 * In case of update operation, we calculate free. 535 */ 536 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr); 537 if (found) 538 free = free + ENTRY_SIZE(here); 539 540 if (unlikely(free < newsize)) { 541 error = -ENOSPC; 542 goto exit; 543 } 544 } 545 546 /* 2. Remove old entry */ 547 if (found) { 548 /* 549 * If entry is found, remove old entry. 550 * If not found, remove operation is not needed. 551 */ 552 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here); 553 int oldsize = ENTRY_SIZE(here); 554 555 memmove(here, next, (char *)last - (char *)next); 556 last = (struct f2fs_xattr_entry *)((char *)last - oldsize); 557 memset(last, 0, oldsize); 558 } 559 560 new_hsize = (char *)last - (char *)base_addr; 561 562 /* 3. Write new entry */ 563 if (value) { 564 char *pval; 565 /* 566 * Before we come here, old entry is removed. 567 * We just write new entry. 568 */ 569 memset(last, 0, newsize); 570 last->e_name_index = index; 571 last->e_name_len = len; 572 memcpy(last->e_name, name, len); 573 pval = last->e_name + len; 574 memcpy(pval, value, size); 575 last->e_value_size = cpu_to_le16(size); 576 new_hsize += newsize; 577 } 578 579 error = write_all_xattrs(inode, new_hsize, base_addr, ipage); 580 if (error) 581 goto exit; 582 583 if (is_inode_flag_set(fi, FI_ACL_MODE)) { 584 inode->i_mode = fi->i_acl_mode; 585 inode->i_ctime = CURRENT_TIME; 586 clear_inode_flag(fi, FI_ACL_MODE); 587 } 588 if (index == F2FS_XATTR_INDEX_ENCRYPTION && 589 !strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT)) 590 f2fs_set_encrypted_inode(inode); 591 592 if (ipage) 593 update_inode(inode, ipage); 594 else 595 update_inode_page(inode); 596 exit: 597 kzfree(base_addr); 598 return error; 599 } 600 601 int f2fs_setxattr(struct inode *inode, int index, const char *name, 602 const void *value, size_t size, 603 struct page *ipage, int flags) 604 { 605 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 606 int err; 607 608 /* this case is only from init_inode_metadata */ 609 if (ipage) 610 return __f2fs_setxattr(inode, index, name, value, 611 size, ipage, flags); 612 f2fs_balance_fs(sbi); 613 614 f2fs_lock_op(sbi); 615 /* protect xattr_ver */ 616 down_write(&F2FS_I(inode)->i_sem); 617 err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags); 618 up_write(&F2FS_I(inode)->i_sem); 619 f2fs_unlock_op(sbi); 620 621 return err; 622 } 623