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 int read_all_xattrs(struct inode *inode, struct page *ipage, 221 void **base_addr) 222 { 223 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 224 struct f2fs_xattr_header *header; 225 size_t size = PAGE_SIZE, inline_size = 0; 226 void *txattr_addr; 227 int err; 228 229 inline_size = inline_xattr_size(inode); 230 231 txattr_addr = kzalloc(inline_size + size, GFP_F2FS_ZERO); 232 if (!txattr_addr) 233 return -ENOMEM; 234 235 /* read from inline xattr */ 236 if (inline_size) { 237 struct page *page = NULL; 238 void *inline_addr; 239 240 if (ipage) { 241 inline_addr = inline_xattr_addr(ipage); 242 } else { 243 page = get_node_page(sbi, inode->i_ino); 244 if (IS_ERR(page)) { 245 err = PTR_ERR(page); 246 goto fail; 247 } 248 inline_addr = inline_xattr_addr(page); 249 } 250 memcpy(txattr_addr, inline_addr, inline_size); 251 f2fs_put_page(page, 1); 252 } 253 254 /* read from xattr node block */ 255 if (F2FS_I(inode)->i_xattr_nid) { 256 struct page *xpage; 257 void *xattr_addr; 258 259 /* The inode already has an extended attribute block. */ 260 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 261 if (IS_ERR(xpage)) { 262 err = PTR_ERR(xpage); 263 goto fail; 264 } 265 266 xattr_addr = page_address(xpage); 267 memcpy(txattr_addr + inline_size, xattr_addr, PAGE_SIZE); 268 f2fs_put_page(xpage, 1); 269 } 270 271 header = XATTR_HDR(txattr_addr); 272 273 /* never been allocated xattrs */ 274 if (le32_to_cpu(header->h_magic) != F2FS_XATTR_MAGIC) { 275 header->h_magic = cpu_to_le32(F2FS_XATTR_MAGIC); 276 header->h_refcount = cpu_to_le32(1); 277 } 278 *base_addr = txattr_addr; 279 return 0; 280 fail: 281 kzfree(txattr_addr); 282 return err; 283 } 284 285 static inline int write_all_xattrs(struct inode *inode, __u32 hsize, 286 void *txattr_addr, struct page *ipage) 287 { 288 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 289 size_t inline_size = 0; 290 void *xattr_addr; 291 struct page *xpage; 292 nid_t new_nid = 0; 293 int err; 294 295 inline_size = inline_xattr_size(inode); 296 297 if (hsize > inline_size && !F2FS_I(inode)->i_xattr_nid) 298 if (!alloc_nid(sbi, &new_nid)) 299 return -ENOSPC; 300 301 /* write to inline xattr */ 302 if (inline_size) { 303 struct page *page = NULL; 304 void *inline_addr; 305 306 if (ipage) { 307 inline_addr = inline_xattr_addr(ipage); 308 f2fs_wait_on_page_writeback(ipage, NODE, true); 309 set_page_dirty(ipage); 310 } else { 311 page = get_node_page(sbi, inode->i_ino); 312 if (IS_ERR(page)) { 313 alloc_nid_failed(sbi, new_nid); 314 return PTR_ERR(page); 315 } 316 inline_addr = inline_xattr_addr(page); 317 f2fs_wait_on_page_writeback(page, NODE, true); 318 } 319 memcpy(inline_addr, txattr_addr, inline_size); 320 f2fs_put_page(page, 1); 321 322 /* no need to use xattr node block */ 323 if (hsize <= inline_size) { 324 err = truncate_xattr_node(inode, ipage); 325 alloc_nid_failed(sbi, new_nid); 326 return err; 327 } 328 } 329 330 /* write to xattr node block */ 331 if (F2FS_I(inode)->i_xattr_nid) { 332 xpage = get_node_page(sbi, F2FS_I(inode)->i_xattr_nid); 333 if (IS_ERR(xpage)) { 334 alloc_nid_failed(sbi, new_nid); 335 return PTR_ERR(xpage); 336 } 337 f2fs_bug_on(sbi, new_nid); 338 f2fs_wait_on_page_writeback(xpage, NODE, true); 339 } else { 340 struct dnode_of_data dn; 341 set_new_dnode(&dn, inode, NULL, NULL, new_nid); 342 xpage = new_node_page(&dn, XATTR_NODE_OFFSET, ipage); 343 if (IS_ERR(xpage)) { 344 alloc_nid_failed(sbi, new_nid); 345 return PTR_ERR(xpage); 346 } 347 alloc_nid_done(sbi, new_nid); 348 } 349 350 xattr_addr = page_address(xpage); 351 memcpy(xattr_addr, txattr_addr + inline_size, PAGE_SIZE - 352 sizeof(struct node_footer)); 353 set_page_dirty(xpage); 354 f2fs_put_page(xpage, 1); 355 356 /* need to checkpoint during fsync */ 357 F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi)); 358 return 0; 359 } 360 361 int f2fs_getxattr(struct inode *inode, int index, const char *name, 362 void *buffer, size_t buffer_size, struct page *ipage) 363 { 364 struct f2fs_xattr_entry *entry; 365 void *base_addr; 366 int error = 0; 367 size_t size, len; 368 369 if (name == NULL) 370 return -EINVAL; 371 372 len = strlen(name); 373 if (len > F2FS_NAME_LEN) 374 return -ERANGE; 375 376 error = read_all_xattrs(inode, ipage, &base_addr); 377 if (error) 378 return error; 379 380 entry = __find_xattr(base_addr, index, len, name); 381 if (IS_XATTR_LAST_ENTRY(entry)) { 382 error = -ENODATA; 383 goto cleanup; 384 } 385 386 size = le16_to_cpu(entry->e_value_size); 387 388 if (buffer && size > buffer_size) { 389 error = -ERANGE; 390 goto cleanup; 391 } 392 393 if (buffer) { 394 char *pval = entry->e_name + entry->e_name_len; 395 memcpy(buffer, pval, size); 396 } 397 error = size; 398 399 cleanup: 400 kzfree(base_addr); 401 return error; 402 } 403 404 ssize_t f2fs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 405 { 406 struct inode *inode = d_inode(dentry); 407 struct f2fs_xattr_entry *entry; 408 void *base_addr; 409 int error = 0; 410 size_t rest = buffer_size; 411 412 error = read_all_xattrs(inode, NULL, &base_addr); 413 if (error) 414 return error; 415 416 list_for_each_xattr(entry, base_addr) { 417 const struct xattr_handler *handler = 418 f2fs_xattr_handler(entry->e_name_index); 419 const char *prefix; 420 size_t prefix_len; 421 size_t size; 422 423 if (!handler || (handler->list && !handler->list(dentry))) 424 continue; 425 426 prefix = handler->prefix ?: handler->name; 427 prefix_len = strlen(prefix); 428 size = prefix_len + entry->e_name_len + 1; 429 if (buffer) { 430 if (size > rest) { 431 error = -ERANGE; 432 goto cleanup; 433 } 434 memcpy(buffer, prefix, prefix_len); 435 buffer += prefix_len; 436 memcpy(buffer, entry->e_name, entry->e_name_len); 437 buffer += entry->e_name_len; 438 *buffer++ = 0; 439 } 440 rest -= size; 441 } 442 error = buffer_size - rest; 443 cleanup: 444 kzfree(base_addr); 445 return error; 446 } 447 448 static int __f2fs_setxattr(struct inode *inode, int index, 449 const char *name, const void *value, size_t size, 450 struct page *ipage, int flags) 451 { 452 struct f2fs_xattr_entry *here, *last; 453 void *base_addr; 454 int found, newsize; 455 size_t len; 456 __u32 new_hsize; 457 int error = 0; 458 459 if (name == NULL) 460 return -EINVAL; 461 462 if (value == NULL) 463 size = 0; 464 465 len = strlen(name); 466 467 if (len > F2FS_NAME_LEN) 468 return -ERANGE; 469 470 if (size > MAX_VALUE_LEN(inode)) 471 return -E2BIG; 472 473 error = read_all_xattrs(inode, ipage, &base_addr); 474 if (error) 475 return error; 476 477 /* find entry with wanted name. */ 478 here = __find_xattr(base_addr, index, len, name); 479 480 found = IS_XATTR_LAST_ENTRY(here) ? 0 : 1; 481 482 if ((flags & XATTR_REPLACE) && !found) { 483 error = -ENODATA; 484 goto exit; 485 } else if ((flags & XATTR_CREATE) && found) { 486 error = -EEXIST; 487 goto exit; 488 } 489 490 last = here; 491 while (!IS_XATTR_LAST_ENTRY(last)) 492 last = XATTR_NEXT_ENTRY(last); 493 494 newsize = XATTR_ALIGN(sizeof(struct f2fs_xattr_entry) + len + size); 495 496 /* 1. Check space */ 497 if (value) { 498 int free; 499 /* 500 * If value is NULL, it is remove operation. 501 * In case of update operation, we calculate free. 502 */ 503 free = MIN_OFFSET(inode) - ((char *)last - (char *)base_addr); 504 if (found) 505 free = free + ENTRY_SIZE(here); 506 507 if (unlikely(free < newsize)) { 508 error = -E2BIG; 509 goto exit; 510 } 511 } 512 513 /* 2. Remove old entry */ 514 if (found) { 515 /* 516 * If entry is found, remove old entry. 517 * If not found, remove operation is not needed. 518 */ 519 struct f2fs_xattr_entry *next = XATTR_NEXT_ENTRY(here); 520 int oldsize = ENTRY_SIZE(here); 521 522 memmove(here, next, (char *)last - (char *)next); 523 last = (struct f2fs_xattr_entry *)((char *)last - oldsize); 524 memset(last, 0, oldsize); 525 } 526 527 new_hsize = (char *)last - (char *)base_addr; 528 529 /* 3. Write new entry */ 530 if (value) { 531 char *pval; 532 /* 533 * Before we come here, old entry is removed. 534 * We just write new entry. 535 */ 536 last->e_name_index = index; 537 last->e_name_len = len; 538 memcpy(last->e_name, name, len); 539 pval = last->e_name + len; 540 memcpy(pval, value, size); 541 last->e_value_size = cpu_to_le16(size); 542 new_hsize += newsize; 543 } 544 545 error = write_all_xattrs(inode, new_hsize, base_addr, ipage); 546 if (error) 547 goto exit; 548 549 if (is_inode_flag_set(inode, FI_ACL_MODE)) { 550 inode->i_mode = F2FS_I(inode)->i_acl_mode; 551 inode->i_ctime = current_time(inode); 552 clear_inode_flag(inode, FI_ACL_MODE); 553 } 554 if (index == F2FS_XATTR_INDEX_ENCRYPTION && 555 !strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT)) 556 f2fs_set_encrypted_inode(inode); 557 f2fs_mark_inode_dirty_sync(inode, true); 558 if (!error && S_ISDIR(inode->i_mode)) 559 set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP); 560 exit: 561 kzfree(base_addr); 562 return error; 563 } 564 565 int f2fs_setxattr(struct inode *inode, int index, const char *name, 566 const void *value, size_t size, 567 struct page *ipage, int flags) 568 { 569 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 570 int err; 571 572 /* this case is only from init_inode_metadata */ 573 if (ipage) 574 return __f2fs_setxattr(inode, index, name, value, 575 size, ipage, flags); 576 f2fs_balance_fs(sbi, true); 577 578 f2fs_lock_op(sbi); 579 /* protect xattr_ver */ 580 down_write(&F2FS_I(inode)->i_sem); 581 err = __f2fs_setxattr(inode, index, name, value, size, ipage, flags); 582 up_write(&F2FS_I(inode)->i_sem); 583 f2fs_unlock_op(sbi); 584 585 f2fs_update_time(sbi, REQ_TIME); 586 return err; 587 } 588