1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2017-2018 HUAWEI, Inc. 4 * https://www.huawei.com/ 5 * Copyright (C) 2021-2022, Alibaba Cloud 6 */ 7 #include <linux/security.h> 8 #include <linux/xxhash.h> 9 #include "xattr.h" 10 11 struct erofs_xattr_iter { 12 struct super_block *sb; 13 struct erofs_buf buf; 14 erofs_off_t pos; 15 void *kaddr; 16 17 char *buffer; 18 int buffer_size, buffer_ofs; 19 20 /* getxattr */ 21 int index, infix_len; 22 struct qstr name; 23 24 /* listxattr */ 25 struct dentry *dentry; 26 }; 27 28 static const char *erofs_xattr_prefix(unsigned int idx, struct dentry *dentry); 29 30 static int erofs_init_inode_xattrs(struct inode *inode) 31 { 32 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 33 struct erofs_inode *vi = EROFS_I(inode); 34 struct super_block *sb = inode->i_sb; 35 const struct erofs_xattr_ibody_header *ih; 36 __le32 *xattr_id; 37 erofs_off_t pos; 38 unsigned int i; 39 int ret = 0; 40 41 if (!vi->xattr_isize) 42 return -ENODATA; 43 44 /* the most case is that xattrs of this inode are initialized. */ 45 if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) { 46 /* 47 * paired with smp_mb() at the end of the function to ensure 48 * fields will only be observed after the bit is set. 49 */ 50 smp_mb(); 51 return 0; 52 } 53 if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE)) 54 return -ERESTARTSYS; 55 56 /* someone has initialized xattrs for us? */ 57 if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) 58 goto out_unlock; 59 60 /* 61 * bypass all xattr operations if ->xattr_isize is not greater than 62 * sizeof(struct erofs_xattr_ibody_header), in detail: 63 * 1) it is not enough to contain erofs_xattr_ibody_header then 64 * ->xattr_isize should be 0 (it means no xattr); 65 * 2) it is just to contain erofs_xattr_ibody_header, which is on-disk 66 * undefined right now (maybe use later with some new sb feature). 67 */ 68 if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) { 69 erofs_err(sb, "xattr_isize %d of nid %llu is not supported yet", 70 vi->xattr_isize, vi->nid); 71 ret = -EOPNOTSUPP; 72 goto out_unlock; 73 } else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) { 74 erofs_err(sb, "bogus xattr ibody @ nid %llu", vi->nid); 75 DBG_BUGON(1); 76 ret = -EFSCORRUPTED; 77 goto out_unlock; 78 } 79 80 pos = erofs_iloc(inode) + vi->inode_isize; 81 ih = erofs_read_metabuf(&buf, sb, pos, erofs_inode_in_metabox(inode)); 82 if (IS_ERR(ih)) { 83 ret = PTR_ERR(ih); 84 goto out_unlock; 85 } 86 vi->xattr_name_filter = le32_to_cpu(ih->h_name_filter); 87 vi->xattr_shared_count = ih->h_shared_count; 88 if ((u32)vi->xattr_shared_count * sizeof(__le32) > 89 vi->xattr_isize - sizeof(struct erofs_xattr_ibody_header)) { 90 erofs_err(sb, "invalid h_shared_count %u @ nid %llu", 91 vi->xattr_shared_count, vi->nid); 92 ret = -EFSCORRUPTED; 93 goto out_unlock; 94 } 95 vi->xattr_shared_xattrs = kmalloc_objs(uint, vi->xattr_shared_count); 96 if (!vi->xattr_shared_xattrs) { 97 ret = -ENOMEM; 98 goto out_unlock; 99 } 100 101 /* skip the ibody header and read the shared xattr array */ 102 pos += sizeof(struct erofs_xattr_ibody_header); 103 for (i = 0; i < vi->xattr_shared_count; ++i) { 104 xattr_id = erofs_bread(&buf, pos + i * sizeof(__le32), true); 105 if (IS_ERR(xattr_id)) { 106 kfree(vi->xattr_shared_xattrs); 107 vi->xattr_shared_xattrs = NULL; 108 ret = PTR_ERR(xattr_id); 109 goto out_unlock; 110 } 111 vi->xattr_shared_xattrs[i] = le32_to_cpu(*xattr_id); 112 } 113 114 /* paired with smp_mb() at the beginning of the function. */ 115 smp_mb(); 116 set_bit(EROFS_I_EA_INITED_BIT, &vi->flags); 117 out_unlock: 118 erofs_put_metabuf(&buf); 119 clear_and_wake_up_bit(EROFS_I_BL_XATTR_BIT, &vi->flags); 120 return ret; 121 } 122 123 static int erofs_xattr_copy_to_buffer(struct erofs_xattr_iter *it, 124 unsigned int len) 125 { 126 unsigned int slice, processed; 127 struct super_block *sb = it->sb; 128 129 for (processed = 0; processed < len; processed += slice) { 130 it->kaddr = erofs_bread(&it->buf, it->pos, true); 131 if (IS_ERR(it->kaddr)) 132 return PTR_ERR(it->kaddr); 133 134 slice = min_t(unsigned int, sb->s_blocksize - 135 erofs_blkoff(sb, it->pos), len - processed); 136 memcpy(it->buffer + it->buffer_ofs, it->kaddr, slice); 137 it->buffer_ofs += slice; 138 it->pos += slice; 139 } 140 return 0; 141 } 142 143 static int erofs_listxattr_foreach(struct erofs_xattr_iter *it) 144 { 145 struct erofs_xattr_entry entry; 146 unsigned int base_index, name_total, prefix_len, infix_len = 0; 147 const char *prefix, *infix = NULL; 148 int err; 149 150 /* 1. handle xattr entry */ 151 entry = *(struct erofs_xattr_entry *)it->kaddr; 152 it->pos += sizeof(struct erofs_xattr_entry); 153 154 base_index = entry.e_name_index; 155 if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) { 156 struct erofs_sb_info *sbi = EROFS_SB(it->sb); 157 struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes + 158 (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); 159 160 if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) 161 return 0; 162 infix = pf->prefix->infix; 163 infix_len = pf->infix_len; 164 base_index = pf->prefix->base_index; 165 } 166 167 prefix = erofs_xattr_prefix(base_index, it->dentry); 168 if (!prefix) 169 return 0; 170 prefix_len = strlen(prefix); 171 name_total = prefix_len + infix_len + entry.e_name_len + 1; 172 173 if (!it->buffer) { 174 it->buffer_ofs += name_total; 175 return 0; 176 } 177 178 if (it->buffer_ofs + name_total > it->buffer_size) 179 return -ERANGE; 180 181 memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len); 182 memcpy(it->buffer + it->buffer_ofs + prefix_len, infix, infix_len); 183 it->buffer_ofs += prefix_len + infix_len; 184 185 /* 2. handle xattr name */ 186 err = erofs_xattr_copy_to_buffer(it, entry.e_name_len); 187 if (err) 188 return err; 189 190 it->buffer[it->buffer_ofs++] = '\0'; 191 return 0; 192 } 193 194 static int erofs_getxattr_foreach(struct erofs_xattr_iter *it) 195 { 196 struct super_block *sb = it->sb; 197 struct erofs_xattr_entry entry; 198 unsigned int slice, processed, value_sz; 199 200 /* 1. handle xattr entry */ 201 entry = *(struct erofs_xattr_entry *)it->kaddr; 202 it->pos += sizeof(struct erofs_xattr_entry); 203 value_sz = le16_to_cpu(entry.e_value_size); 204 205 /* should also match the infix for long name prefixes */ 206 if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) { 207 struct erofs_sb_info *sbi = EROFS_SB(sb); 208 struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes + 209 (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); 210 211 if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) 212 return -ENODATA; 213 214 if (it->index != pf->prefix->base_index || 215 it->name.len != entry.e_name_len + pf->infix_len) 216 return -ENODATA; 217 218 if (memcmp(it->name.name, pf->prefix->infix, pf->infix_len)) 219 return -ENODATA; 220 221 it->infix_len = pf->infix_len; 222 } else { 223 if (it->index != entry.e_name_index || 224 it->name.len != entry.e_name_len) 225 return -ENODATA; 226 227 it->infix_len = 0; 228 } 229 230 /* 2. handle xattr name */ 231 for (processed = 0; processed < entry.e_name_len; processed += slice) { 232 it->kaddr = erofs_bread(&it->buf, it->pos, true); 233 if (IS_ERR(it->kaddr)) 234 return PTR_ERR(it->kaddr); 235 236 slice = min_t(unsigned int, 237 sb->s_blocksize - erofs_blkoff(sb, it->pos), 238 entry.e_name_len - processed); 239 if (memcmp(it->name.name + it->infix_len + processed, 240 it->kaddr, slice)) 241 return -ENODATA; 242 it->pos += slice; 243 } 244 245 /* 3. handle xattr value */ 246 if (!it->buffer) { 247 it->buffer_ofs = value_sz; 248 return 0; 249 } 250 251 if (it->buffer_size < value_sz) 252 return -ERANGE; 253 254 return erofs_xattr_copy_to_buffer(it, value_sz); 255 } 256 257 static int erofs_xattr_iter_inline(struct erofs_xattr_iter *it, 258 struct inode *inode, bool getxattr) 259 { 260 struct erofs_inode *const vi = EROFS_I(inode); 261 unsigned int xattr_header_sz, remaining, entry_sz; 262 erofs_off_t next_pos; 263 int ret; 264 265 xattr_header_sz = sizeof(struct erofs_xattr_ibody_header) + 266 sizeof(u32) * vi->xattr_shared_count; 267 if (xattr_header_sz >= vi->xattr_isize) { 268 DBG_BUGON(xattr_header_sz > vi->xattr_isize); 269 return -ENODATA; 270 } 271 272 ret = erofs_init_metabuf(&it->buf, it->sb, erofs_inode_in_metabox(inode)); 273 if (ret) 274 return ret; 275 remaining = vi->xattr_isize - xattr_header_sz; 276 it->pos = erofs_iloc(inode) + vi->inode_isize + xattr_header_sz; 277 278 while (remaining) { 279 it->kaddr = erofs_bread(&it->buf, it->pos, true); 280 if (IS_ERR(it->kaddr)) 281 return PTR_ERR(it->kaddr); 282 283 entry_sz = erofs_xattr_entry_size(it->kaddr); 284 /* xattr on-disk corruption: xattr entry beyond xattr_isize */ 285 if (remaining < entry_sz) { 286 DBG_BUGON(1); 287 return -EFSCORRUPTED; 288 } 289 remaining -= entry_sz; 290 next_pos = it->pos + entry_sz; 291 292 if (getxattr) 293 ret = erofs_getxattr_foreach(it); 294 else 295 ret = erofs_listxattr_foreach(it); 296 if ((getxattr && ret != -ENODATA) || (!getxattr && ret)) 297 break; 298 299 it->pos = next_pos; 300 } 301 return ret; 302 } 303 304 static int erofs_xattr_iter_shared(struct erofs_xattr_iter *it, 305 struct inode *inode, bool getxattr) 306 { 307 struct erofs_inode *const vi = EROFS_I(inode); 308 struct super_block *const sb = it->sb; 309 struct erofs_sb_info *sbi = EROFS_SB(sb); 310 unsigned int i = 0; 311 int ret; 312 313 ret = erofs_init_metabuf(&it->buf, sb, 314 erofs_sb_has_shared_ea_in_metabox(sbi)); 315 if (ret) 316 return ret; 317 318 while (i < vi->xattr_shared_count) { 319 it->pos = erofs_pos(sb, sbi->xattr_blkaddr) + 320 vi->xattr_shared_xattrs[i++] * sizeof(__le32); 321 it->kaddr = erofs_bread(&it->buf, it->pos, true); 322 if (IS_ERR(it->kaddr)) 323 return PTR_ERR(it->kaddr); 324 325 if (getxattr) 326 ret = erofs_getxattr_foreach(it); 327 else 328 ret = erofs_listxattr_foreach(it); 329 if ((getxattr && ret != -ENODATA) || (!getxattr && ret)) 330 break; 331 } 332 return i ? ret : -ENODATA; 333 } 334 335 static int erofs_getxattr(struct inode *inode, int index, const char *name, 336 void *buffer, size_t buffer_size) 337 { 338 int ret; 339 unsigned int hashbit; 340 struct erofs_xattr_iter it; 341 struct erofs_inode *vi = EROFS_I(inode); 342 struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); 343 344 if (!name) 345 return -EINVAL; 346 347 ret = erofs_init_inode_xattrs(inode); 348 if (ret) 349 return ret; 350 351 /* reserved flag is non-zero if there's any change of on-disk format */ 352 if (erofs_sb_has_xattr_filter(sbi) && !sbi->xattr_filter_reserved) { 353 hashbit = xxh32(name, strlen(name), 354 EROFS_XATTR_FILTER_SEED + index); 355 hashbit &= EROFS_XATTR_FILTER_BITS - 1; 356 if (vi->xattr_name_filter & (1U << hashbit)) 357 return -ENODATA; 358 } 359 360 it.index = index; 361 it.name = QSTR(name); 362 if (it.name.len > EROFS_NAME_LEN) 363 return -ERANGE; 364 365 it.sb = inode->i_sb; 366 it.buf = __EROFS_BUF_INITIALIZER; 367 it.buffer = buffer; 368 it.buffer_size = buffer_size; 369 it.buffer_ofs = 0; 370 371 ret = erofs_xattr_iter_inline(&it, inode, true); 372 if (ret == -ENODATA) 373 ret = erofs_xattr_iter_shared(&it, inode, true); 374 erofs_put_metabuf(&it.buf); 375 return ret ? ret : it.buffer_ofs; 376 } 377 378 ssize_t erofs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) 379 { 380 int ret; 381 struct erofs_xattr_iter it; 382 struct inode *inode = d_inode(dentry); 383 384 ret = erofs_init_inode_xattrs(inode); 385 if (ret == -ENODATA) 386 return 0; 387 if (ret) 388 return ret; 389 390 it.sb = dentry->d_sb; 391 it.buf = __EROFS_BUF_INITIALIZER; 392 it.dentry = dentry; 393 it.buffer = buffer; 394 it.buffer_size = buffer_size; 395 it.buffer_ofs = 0; 396 397 ret = erofs_xattr_iter_inline(&it, inode, false); 398 if (!ret || ret == -ENODATA) 399 ret = erofs_xattr_iter_shared(&it, inode, false); 400 if (ret == -ENODATA) 401 ret = 0; 402 erofs_put_metabuf(&it.buf); 403 return ret ? ret : it.buffer_ofs; 404 } 405 406 static bool erofs_xattr_user_list(struct dentry *dentry) 407 { 408 return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER); 409 } 410 411 static bool erofs_xattr_trusted_list(struct dentry *dentry) 412 { 413 return capable(CAP_SYS_ADMIN); 414 } 415 416 static int erofs_xattr_generic_get(const struct xattr_handler *handler, 417 struct dentry *unused, struct inode *inode, 418 const char *name, void *buffer, size_t size) 419 { 420 if (handler->flags == EROFS_XATTR_INDEX_USER && 421 !test_opt(&EROFS_I_SB(inode)->opt, XATTR_USER)) 422 return -EOPNOTSUPP; 423 424 return erofs_getxattr(inode, handler->flags, name, buffer, size); 425 } 426 427 static const struct xattr_handler erofs_xattr_user_handler = { 428 .prefix = XATTR_USER_PREFIX, 429 .flags = EROFS_XATTR_INDEX_USER, 430 .list = erofs_xattr_user_list, 431 .get = erofs_xattr_generic_get, 432 }; 433 434 static const struct xattr_handler erofs_xattr_trusted_handler = { 435 .prefix = XATTR_TRUSTED_PREFIX, 436 .flags = EROFS_XATTR_INDEX_TRUSTED, 437 .list = erofs_xattr_trusted_list, 438 .get = erofs_xattr_generic_get, 439 }; 440 441 #ifdef CONFIG_EROFS_FS_SECURITY 442 static const struct xattr_handler erofs_xattr_security_handler = { 443 .prefix = XATTR_SECURITY_PREFIX, 444 .flags = EROFS_XATTR_INDEX_SECURITY, 445 .get = erofs_xattr_generic_get, 446 }; 447 #endif 448 449 const struct xattr_handler * const erofs_xattr_handlers[] = { 450 &erofs_xattr_user_handler, 451 &erofs_xattr_trusted_handler, 452 #ifdef CONFIG_EROFS_FS_SECURITY 453 &erofs_xattr_security_handler, 454 #endif 455 NULL, 456 }; 457 458 static const char *erofs_xattr_prefix(unsigned int idx, struct dentry *dentry) 459 { 460 static const struct xattr_handler * const xattr_handler_map[] = { 461 [EROFS_XATTR_INDEX_USER] = &erofs_xattr_user_handler, 462 #ifdef CONFIG_EROFS_FS_POSIX_ACL 463 [EROFS_XATTR_INDEX_POSIX_ACL_ACCESS] = &nop_posix_acl_access, 464 [EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &nop_posix_acl_default, 465 #endif 466 [EROFS_XATTR_INDEX_TRUSTED] = &erofs_xattr_trusted_handler, 467 #ifdef CONFIG_EROFS_FS_SECURITY 468 [EROFS_XATTR_INDEX_SECURITY] = &erofs_xattr_security_handler, 469 #endif 470 }; 471 const struct xattr_handler *handler = NULL; 472 473 if (idx && idx < ARRAY_SIZE(xattr_handler_map)) { 474 handler = xattr_handler_map[idx]; 475 if (xattr_handler_can_list(handler, dentry)) 476 return xattr_prefix(handler); 477 } 478 return NULL; 479 } 480 481 void erofs_xattr_prefixes_cleanup(struct super_block *sb) 482 { 483 struct erofs_sb_info *sbi = EROFS_SB(sb); 484 int i; 485 486 if (sbi->xattr_prefixes) { 487 for (i = 0; i < sbi->xattr_prefix_count; i++) 488 kfree(sbi->xattr_prefixes[i].prefix); 489 kfree(sbi->xattr_prefixes); 490 sbi->xattr_prefixes = NULL; 491 } 492 } 493 494 int erofs_xattr_prefixes_init(struct super_block *sb) 495 { 496 struct erofs_sb_info *sbi = EROFS_SB(sb); 497 struct erofs_buf buf = __EROFS_BUF_INITIALIZER; 498 erofs_off_t pos = (erofs_off_t)sbi->xattr_prefix_start << 2; 499 struct erofs_xattr_prefix_item *pfs; 500 int ret = 0, i, len; 501 bool plain = erofs_sb_has_plain_xattr_pfx(sbi); 502 503 if (!sbi->xattr_prefix_count) 504 return 0; 505 506 pfs = kzalloc_objs(*pfs, sbi->xattr_prefix_count); 507 if (!pfs) 508 return -ENOMEM; 509 510 if (!plain) { 511 if (erofs_sb_has_metabox(sbi)) 512 (void)erofs_init_metabuf(&buf, sb, true); 513 else if (sbi->packed_inode) 514 buf.mapping = sbi->packed_inode->i_mapping; 515 else 516 plain = true; 517 } 518 if (plain) 519 (void)erofs_init_metabuf(&buf, sb, false); 520 521 for (i = 0; i < sbi->xattr_prefix_count; i++) { 522 void *ptr = erofs_read_metadata(sb, &buf, &pos, &len); 523 524 if (IS_ERR(ptr)) { 525 ret = PTR_ERR(ptr); 526 break; 527 } else if (len < sizeof(*pfs->prefix) || 528 len > EROFS_NAME_LEN + sizeof(*pfs->prefix)) { 529 kfree(ptr); 530 ret = -EFSCORRUPTED; 531 break; 532 } 533 pfs[i].prefix = ptr; 534 pfs[i].infix_len = len - sizeof(struct erofs_xattr_long_prefix); 535 } 536 537 erofs_put_metabuf(&buf); 538 if (!ret && erofs_sb_has_ishare_xattrs(sbi)) { 539 struct erofs_xattr_prefix_item *pf = pfs + sbi->ishare_xattr_prefix_id; 540 struct erofs_xattr_long_prefix *newpfx; 541 542 newpfx = krealloc(pf->prefix, 543 sizeof(*newpfx) + pf->infix_len + 1, GFP_KERNEL); 544 if (newpfx) { 545 newpfx->infix[pf->infix_len] = '\0'; 546 pf->prefix = newpfx; 547 } else { 548 ret = -ENOMEM; 549 } 550 } 551 sbi->xattr_prefixes = pfs; 552 if (ret) 553 erofs_xattr_prefixes_cleanup(sb); 554 return ret; 555 } 556 557 #ifdef CONFIG_EROFS_FS_POSIX_ACL 558 struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu) 559 { 560 struct posix_acl *acl; 561 int prefix, rc; 562 char *value = NULL; 563 564 if (rcu) 565 return ERR_PTR(-ECHILD); 566 567 switch (type) { 568 case ACL_TYPE_ACCESS: 569 prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS; 570 break; 571 case ACL_TYPE_DEFAULT: 572 prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT; 573 break; 574 default: 575 return ERR_PTR(-EINVAL); 576 } 577 578 rc = erofs_getxattr(inode, prefix, "", NULL, 0); 579 if (rc > 0) { 580 value = kmalloc(rc, GFP_KERNEL); 581 if (!value) 582 return ERR_PTR(-ENOMEM); 583 rc = erofs_getxattr(inode, prefix, "", value, rc); 584 } 585 586 if (rc == -ENODATA) 587 acl = NULL; 588 else if (rc < 0) 589 acl = ERR_PTR(rc); 590 else 591 acl = posix_acl_from_xattr(&init_user_ns, value, rc); 592 kfree(value); 593 return acl; 594 } 595 596 bool erofs_inode_has_noacl(struct inode *inode, void *kaddr, unsigned int ofs) 597 { 598 static const unsigned int bitmask = 599 BIT(21) | /* system.posix_acl_default */ 600 BIT(30); /* system.posix_acl_access */ 601 struct erofs_sb_info *sbi = EROFS_I_SB(inode); 602 const struct erofs_xattr_ibody_header *ih = kaddr + ofs; 603 604 if (EROFS_I(inode)->xattr_isize < sizeof(*ih)) 605 return true; 606 607 if (erofs_sb_has_xattr_filter(sbi) && !sbi->xattr_filter_reserved && 608 !check_add_overflow(ofs, sizeof(*ih), &ofs) && 609 ofs <= i_blocksize(inode)) { 610 if ((le32_to_cpu(ih->h_name_filter) & bitmask) == bitmask) 611 return true; 612 } 613 return false; 614 } 615 #endif 616 617 #ifdef CONFIG_EROFS_FS_PAGE_CACHE_SHARE 618 int erofs_xattr_fill_inode_fingerprint(struct erofs_inode_fingerprint *fp, 619 struct inode *inode, const char *domain_id) 620 { 621 struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb); 622 struct erofs_xattr_prefix_item *prefix; 623 const char *infix; 624 int valuelen, base_index; 625 626 if (!test_opt(&sbi->opt, INODE_SHARE)) 627 return -EOPNOTSUPP; 628 if (!sbi->xattr_prefixes) 629 return -EINVAL; 630 prefix = sbi->xattr_prefixes + sbi->ishare_xattr_prefix_id; 631 infix = prefix->prefix->infix; 632 base_index = prefix->prefix->base_index; 633 valuelen = erofs_getxattr(inode, base_index, infix, NULL, 0); 634 if (valuelen <= 0 || valuelen > (1 << sbi->blkszbits)) 635 return -EFSCORRUPTED; 636 fp->size = valuelen + (domain_id ? strlen(domain_id) : 0); 637 fp->opaque = kmalloc(fp->size, GFP_KERNEL); 638 if (!fp->opaque) 639 return -ENOMEM; 640 if (valuelen != erofs_getxattr(inode, base_index, infix, 641 fp->opaque, valuelen)) { 642 kfree(fp->opaque); 643 fp->opaque = NULL; 644 return -EFSCORRUPTED; 645 } 646 memcpy(fp->opaque + valuelen, domain_id, fp->size - valuelen); 647 return 0; 648 } 649 #endif 650