1 /** 2 * dir.c - NTFS kernel directory operations. Part of the Linux-NTFS project. 3 * 4 * Copyright (c) 2001-2007 Anton Altaparmakov 5 * Copyright (c) 2002 Richard Russon 6 * 7 * This program/include file is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License as published 9 * by the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program/include file is distributed in the hope that it will be 13 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty 14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program (in the main directory of the Linux-NTFS 19 * distribution in the file COPYING); if not, write to the Free Software 20 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 */ 22 23 #include <linux/buffer_head.h> 24 25 #include "dir.h" 26 #include "aops.h" 27 #include "attrib.h" 28 #include "mft.h" 29 #include "debug.h" 30 #include "ntfs.h" 31 32 /** 33 * The little endian Unicode string $I30 as a global constant. 34 */ 35 ntfschar I30[5] = { const_cpu_to_le16('$'), const_cpu_to_le16('I'), 36 const_cpu_to_le16('3'), const_cpu_to_le16('0'), 0 }; 37 38 /** 39 * ntfs_lookup_inode_by_name - find an inode in a directory given its name 40 * @dir_ni: ntfs inode of the directory in which to search for the name 41 * @uname: Unicode name for which to search in the directory 42 * @uname_len: length of the name @uname in Unicode characters 43 * @res: return the found file name if necessary (see below) 44 * 45 * Look for an inode with name @uname in the directory with inode @dir_ni. 46 * ntfs_lookup_inode_by_name() walks the contents of the directory looking for 47 * the Unicode name. If the name is found in the directory, the corresponding 48 * inode number (>= 0) is returned as a mft reference in cpu format, i.e. it 49 * is a 64-bit number containing the sequence number. 50 * 51 * On error, a negative value is returned corresponding to the error code. In 52 * particular if the inode is not found -ENOENT is returned. Note that you 53 * can't just check the return value for being negative, you have to check the 54 * inode number for being negative which you can extract using MREC(return 55 * value). 56 * 57 * Note, @uname_len does not include the (optional) terminating NULL character. 58 * 59 * Note, we look for a case sensitive match first but we also look for a case 60 * insensitive match at the same time. If we find a case insensitive match, we 61 * save that for the case that we don't find an exact match, where we return 62 * the case insensitive match and setup @res (which we allocate!) with the mft 63 * reference, the file name type, length and with a copy of the little endian 64 * Unicode file name itself. If we match a file name which is in the DOS name 65 * space, we only return the mft reference and file name type in @res. 66 * ntfs_lookup() then uses this to find the long file name in the inode itself. 67 * This is to avoid polluting the dcache with short file names. We want them to 68 * work but we don't care for how quickly one can access them. This also fixes 69 * the dcache aliasing issues. 70 * 71 * Locking: - Caller must hold i_mutex on the directory. 72 * - Each page cache page in the index allocation mapping must be 73 * locked whilst being accessed otherwise we may find a corrupt 74 * page due to it being under ->writepage at the moment which 75 * applies the mst protection fixups before writing out and then 76 * removes them again after the write is complete after which it 77 * unlocks the page. 78 */ 79 MFT_REF ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname, 80 const int uname_len, ntfs_name **res) 81 { 82 ntfs_volume *vol = dir_ni->vol; 83 struct super_block *sb = vol->sb; 84 MFT_RECORD *m; 85 INDEX_ROOT *ir; 86 INDEX_ENTRY *ie; 87 INDEX_ALLOCATION *ia; 88 u8 *index_end; 89 u64 mref; 90 ntfs_attr_search_ctx *ctx; 91 int err, rc; 92 VCN vcn, old_vcn; 93 struct address_space *ia_mapping; 94 struct page *page; 95 u8 *kaddr; 96 ntfs_name *name = NULL; 97 98 BUG_ON(!S_ISDIR(VFS_I(dir_ni)->i_mode)); 99 BUG_ON(NInoAttr(dir_ni)); 100 /* Get hold of the mft record for the directory. */ 101 m = map_mft_record(dir_ni); 102 if (IS_ERR(m)) { 103 ntfs_error(sb, "map_mft_record() failed with error code %ld.", 104 -PTR_ERR(m)); 105 return ERR_MREF(PTR_ERR(m)); 106 } 107 ctx = ntfs_attr_get_search_ctx(dir_ni, m); 108 if (unlikely(!ctx)) { 109 err = -ENOMEM; 110 goto err_out; 111 } 112 /* Find the index root attribute in the mft record. */ 113 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, 114 0, ctx); 115 if (unlikely(err)) { 116 if (err == -ENOENT) { 117 ntfs_error(sb, "Index root attribute missing in " 118 "directory inode 0x%lx.", 119 dir_ni->mft_no); 120 err = -EIO; 121 } 122 goto err_out; 123 } 124 /* Get to the index root value (it's been verified in read_inode). */ 125 ir = (INDEX_ROOT*)((u8*)ctx->attr + 126 le16_to_cpu(ctx->attr->data.resident.value_offset)); 127 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); 128 /* The first index entry. */ 129 ie = (INDEX_ENTRY*)((u8*)&ir->index + 130 le32_to_cpu(ir->index.entries_offset)); 131 /* 132 * Loop until we exceed valid memory (corruption case) or until we 133 * reach the last entry. 134 */ 135 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { 136 /* Bounds checks. */ 137 if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie + 138 sizeof(INDEX_ENTRY_HEADER) > index_end || 139 (u8*)ie + le16_to_cpu(ie->key_length) > 140 index_end) 141 goto dir_err_out; 142 /* 143 * The last entry cannot contain a name. It can however contain 144 * a pointer to a child node in the B+tree so we just break out. 145 */ 146 if (ie->flags & INDEX_ENTRY_END) 147 break; 148 /* 149 * We perform a case sensitive comparison and if that matches 150 * we are done and return the mft reference of the inode (i.e. 151 * the inode number together with the sequence number for 152 * consistency checking). We convert it to cpu format before 153 * returning. 154 */ 155 if (ntfs_are_names_equal(uname, uname_len, 156 (ntfschar*)&ie->key.file_name.file_name, 157 ie->key.file_name.file_name_length, 158 CASE_SENSITIVE, vol->upcase, vol->upcase_len)) { 159 found_it: 160 /* 161 * We have a perfect match, so we don't need to care 162 * about having matched imperfectly before, so we can 163 * free name and set *res to NULL. 164 * However, if the perfect match is a short file name, 165 * we need to signal this through *res, so that 166 * ntfs_lookup() can fix dcache aliasing issues. 167 * As an optimization we just reuse an existing 168 * allocation of *res. 169 */ 170 if (ie->key.file_name.file_name_type == FILE_NAME_DOS) { 171 if (!name) { 172 name = kmalloc(sizeof(ntfs_name), 173 GFP_NOFS); 174 if (!name) { 175 err = -ENOMEM; 176 goto err_out; 177 } 178 } 179 name->mref = le64_to_cpu( 180 ie->data.dir.indexed_file); 181 name->type = FILE_NAME_DOS; 182 name->len = 0; 183 *res = name; 184 } else { 185 kfree(name); 186 *res = NULL; 187 } 188 mref = le64_to_cpu(ie->data.dir.indexed_file); 189 ntfs_attr_put_search_ctx(ctx); 190 unmap_mft_record(dir_ni); 191 return mref; 192 } 193 /* 194 * For a case insensitive mount, we also perform a case 195 * insensitive comparison (provided the file name is not in the 196 * POSIX namespace). If the comparison matches, and the name is 197 * in the WIN32 namespace, we cache the filename in *res so 198 * that the caller, ntfs_lookup(), can work on it. If the 199 * comparison matches, and the name is in the DOS namespace, we 200 * only cache the mft reference and the file name type (we set 201 * the name length to zero for simplicity). 202 */ 203 if (!NVolCaseSensitive(vol) && 204 ie->key.file_name.file_name_type && 205 ntfs_are_names_equal(uname, uname_len, 206 (ntfschar*)&ie->key.file_name.file_name, 207 ie->key.file_name.file_name_length, 208 IGNORE_CASE, vol->upcase, vol->upcase_len)) { 209 int name_size = sizeof(ntfs_name); 210 u8 type = ie->key.file_name.file_name_type; 211 u8 len = ie->key.file_name.file_name_length; 212 213 /* Only one case insensitive matching name allowed. */ 214 if (name) { 215 ntfs_error(sb, "Found already allocated name " 216 "in phase 1. Please run chkdsk " 217 "and if that doesn't find any " 218 "errors please report you saw " 219 "this message to " 220 "linux-ntfs-dev@lists." 221 "sourceforge.net."); 222 goto dir_err_out; 223 } 224 225 if (type != FILE_NAME_DOS) 226 name_size += len * sizeof(ntfschar); 227 name = kmalloc(name_size, GFP_NOFS); 228 if (!name) { 229 err = -ENOMEM; 230 goto err_out; 231 } 232 name->mref = le64_to_cpu(ie->data.dir.indexed_file); 233 name->type = type; 234 if (type != FILE_NAME_DOS) { 235 name->len = len; 236 memcpy(name->name, ie->key.file_name.file_name, 237 len * sizeof(ntfschar)); 238 } else 239 name->len = 0; 240 *res = name; 241 } 242 /* 243 * Not a perfect match, need to do full blown collation so we 244 * know which way in the B+tree we have to go. 245 */ 246 rc = ntfs_collate_names(uname, uname_len, 247 (ntfschar*)&ie->key.file_name.file_name, 248 ie->key.file_name.file_name_length, 1, 249 IGNORE_CASE, vol->upcase, vol->upcase_len); 250 /* 251 * If uname collates before the name of the current entry, there 252 * is definitely no such name in this index but we might need to 253 * descend into the B+tree so we just break out of the loop. 254 */ 255 if (rc == -1) 256 break; 257 /* The names are not equal, continue the search. */ 258 if (rc) 259 continue; 260 /* 261 * Names match with case insensitive comparison, now try the 262 * case sensitive comparison, which is required for proper 263 * collation. 264 */ 265 rc = ntfs_collate_names(uname, uname_len, 266 (ntfschar*)&ie->key.file_name.file_name, 267 ie->key.file_name.file_name_length, 1, 268 CASE_SENSITIVE, vol->upcase, vol->upcase_len); 269 if (rc == -1) 270 break; 271 if (rc) 272 continue; 273 /* 274 * Perfect match, this will never happen as the 275 * ntfs_are_names_equal() call will have gotten a match but we 276 * still treat it correctly. 277 */ 278 goto found_it; 279 } 280 /* 281 * We have finished with this index without success. Check for the 282 * presence of a child node and if not present return -ENOENT, unless 283 * we have got a matching name cached in name in which case return the 284 * mft reference associated with it. 285 */ 286 if (!(ie->flags & INDEX_ENTRY_NODE)) { 287 if (name) { 288 ntfs_attr_put_search_ctx(ctx); 289 unmap_mft_record(dir_ni); 290 return name->mref; 291 } 292 ntfs_debug("Entry not found."); 293 err = -ENOENT; 294 goto err_out; 295 } /* Child node present, descend into it. */ 296 /* Consistency check: Verify that an index allocation exists. */ 297 if (!NInoIndexAllocPresent(dir_ni)) { 298 ntfs_error(sb, "No index allocation attribute but index entry " 299 "requires one. Directory inode 0x%lx is " 300 "corrupt or driver bug.", dir_ni->mft_no); 301 goto err_out; 302 } 303 /* Get the starting vcn of the index_block holding the child node. */ 304 vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8)); 305 ia_mapping = VFS_I(dir_ni)->i_mapping; 306 /* 307 * We are done with the index root and the mft record. Release them, 308 * otherwise we deadlock with ntfs_map_page(). 309 */ 310 ntfs_attr_put_search_ctx(ctx); 311 unmap_mft_record(dir_ni); 312 m = NULL; 313 ctx = NULL; 314 descend_into_child_node: 315 /* 316 * Convert vcn to index into the index allocation attribute in units 317 * of PAGE_CACHE_SIZE and map the page cache page, reading it from 318 * disk if necessary. 319 */ 320 page = ntfs_map_page(ia_mapping, vcn << 321 dir_ni->itype.index.vcn_size_bits >> PAGE_CACHE_SHIFT); 322 if (IS_ERR(page)) { 323 ntfs_error(sb, "Failed to map directory index page, error %ld.", 324 -PTR_ERR(page)); 325 err = PTR_ERR(page); 326 goto err_out; 327 } 328 lock_page(page); 329 kaddr = (u8*)page_address(page); 330 fast_descend_into_child_node: 331 /* Get to the index allocation block. */ 332 ia = (INDEX_ALLOCATION*)(kaddr + ((vcn << 333 dir_ni->itype.index.vcn_size_bits) & ~PAGE_CACHE_MASK)); 334 /* Bounds checks. */ 335 if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE) { 336 ntfs_error(sb, "Out of bounds check failed. Corrupt directory " 337 "inode 0x%lx or driver bug.", dir_ni->mft_no); 338 goto unm_err_out; 339 } 340 /* Catch multi sector transfer fixup errors. */ 341 if (unlikely(!ntfs_is_indx_record(ia->magic))) { 342 ntfs_error(sb, "Directory index record with vcn 0x%llx is " 343 "corrupt. Corrupt inode 0x%lx. Run chkdsk.", 344 (unsigned long long)vcn, dir_ni->mft_no); 345 goto unm_err_out; 346 } 347 if (sle64_to_cpu(ia->index_block_vcn) != vcn) { 348 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " 349 "different from expected VCN (0x%llx). " 350 "Directory inode 0x%lx is corrupt or driver " 351 "bug.", (unsigned long long) 352 sle64_to_cpu(ia->index_block_vcn), 353 (unsigned long long)vcn, dir_ni->mft_no); 354 goto unm_err_out; 355 } 356 if (le32_to_cpu(ia->index.allocated_size) + 0x18 != 357 dir_ni->itype.index.block_size) { 358 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " 359 "0x%lx has a size (%u) differing from the " 360 "directory specified size (%u). Directory " 361 "inode is corrupt or driver bug.", 362 (unsigned long long)vcn, dir_ni->mft_no, 363 le32_to_cpu(ia->index.allocated_size) + 0x18, 364 dir_ni->itype.index.block_size); 365 goto unm_err_out; 366 } 367 index_end = (u8*)ia + dir_ni->itype.index.block_size; 368 if (index_end > kaddr + PAGE_CACHE_SIZE) { 369 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " 370 "0x%lx crosses page boundary. Impossible! " 371 "Cannot access! This is probably a bug in the " 372 "driver.", (unsigned long long)vcn, 373 dir_ni->mft_no); 374 goto unm_err_out; 375 } 376 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); 377 if (index_end > (u8*)ia + dir_ni->itype.index.block_size) { 378 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " 379 "inode 0x%lx exceeds maximum size.", 380 (unsigned long long)vcn, dir_ni->mft_no); 381 goto unm_err_out; 382 } 383 /* The first index entry. */ 384 ie = (INDEX_ENTRY*)((u8*)&ia->index + 385 le32_to_cpu(ia->index.entries_offset)); 386 /* 387 * Iterate similar to above big loop but applied to index buffer, thus 388 * loop until we exceed valid memory (corruption case) or until we 389 * reach the last entry. 390 */ 391 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { 392 /* Bounds check. */ 393 if ((u8*)ie < (u8*)ia || (u8*)ie + 394 sizeof(INDEX_ENTRY_HEADER) > index_end || 395 (u8*)ie + le16_to_cpu(ie->key_length) > 396 index_end) { 397 ntfs_error(sb, "Index entry out of bounds in " 398 "directory inode 0x%lx.", 399 dir_ni->mft_no); 400 goto unm_err_out; 401 } 402 /* 403 * The last entry cannot contain a name. It can however contain 404 * a pointer to a child node in the B+tree so we just break out. 405 */ 406 if (ie->flags & INDEX_ENTRY_END) 407 break; 408 /* 409 * We perform a case sensitive comparison and if that matches 410 * we are done and return the mft reference of the inode (i.e. 411 * the inode number together with the sequence number for 412 * consistency checking). We convert it to cpu format before 413 * returning. 414 */ 415 if (ntfs_are_names_equal(uname, uname_len, 416 (ntfschar*)&ie->key.file_name.file_name, 417 ie->key.file_name.file_name_length, 418 CASE_SENSITIVE, vol->upcase, vol->upcase_len)) { 419 found_it2: 420 /* 421 * We have a perfect match, so we don't need to care 422 * about having matched imperfectly before, so we can 423 * free name and set *res to NULL. 424 * However, if the perfect match is a short file name, 425 * we need to signal this through *res, so that 426 * ntfs_lookup() can fix dcache aliasing issues. 427 * As an optimization we just reuse an existing 428 * allocation of *res. 429 */ 430 if (ie->key.file_name.file_name_type == FILE_NAME_DOS) { 431 if (!name) { 432 name = kmalloc(sizeof(ntfs_name), 433 GFP_NOFS); 434 if (!name) { 435 err = -ENOMEM; 436 goto unm_err_out; 437 } 438 } 439 name->mref = le64_to_cpu( 440 ie->data.dir.indexed_file); 441 name->type = FILE_NAME_DOS; 442 name->len = 0; 443 *res = name; 444 } else { 445 kfree(name); 446 *res = NULL; 447 } 448 mref = le64_to_cpu(ie->data.dir.indexed_file); 449 unlock_page(page); 450 ntfs_unmap_page(page); 451 return mref; 452 } 453 /* 454 * For a case insensitive mount, we also perform a case 455 * insensitive comparison (provided the file name is not in the 456 * POSIX namespace). If the comparison matches, and the name is 457 * in the WIN32 namespace, we cache the filename in *res so 458 * that the caller, ntfs_lookup(), can work on it. If the 459 * comparison matches, and the name is in the DOS namespace, we 460 * only cache the mft reference and the file name type (we set 461 * the name length to zero for simplicity). 462 */ 463 if (!NVolCaseSensitive(vol) && 464 ie->key.file_name.file_name_type && 465 ntfs_are_names_equal(uname, uname_len, 466 (ntfschar*)&ie->key.file_name.file_name, 467 ie->key.file_name.file_name_length, 468 IGNORE_CASE, vol->upcase, vol->upcase_len)) { 469 int name_size = sizeof(ntfs_name); 470 u8 type = ie->key.file_name.file_name_type; 471 u8 len = ie->key.file_name.file_name_length; 472 473 /* Only one case insensitive matching name allowed. */ 474 if (name) { 475 ntfs_error(sb, "Found already allocated name " 476 "in phase 2. Please run chkdsk " 477 "and if that doesn't find any " 478 "errors please report you saw " 479 "this message to " 480 "linux-ntfs-dev@lists." 481 "sourceforge.net."); 482 unlock_page(page); 483 ntfs_unmap_page(page); 484 goto dir_err_out; 485 } 486 487 if (type != FILE_NAME_DOS) 488 name_size += len * sizeof(ntfschar); 489 name = kmalloc(name_size, GFP_NOFS); 490 if (!name) { 491 err = -ENOMEM; 492 goto unm_err_out; 493 } 494 name->mref = le64_to_cpu(ie->data.dir.indexed_file); 495 name->type = type; 496 if (type != FILE_NAME_DOS) { 497 name->len = len; 498 memcpy(name->name, ie->key.file_name.file_name, 499 len * sizeof(ntfschar)); 500 } else 501 name->len = 0; 502 *res = name; 503 } 504 /* 505 * Not a perfect match, need to do full blown collation so we 506 * know which way in the B+tree we have to go. 507 */ 508 rc = ntfs_collate_names(uname, uname_len, 509 (ntfschar*)&ie->key.file_name.file_name, 510 ie->key.file_name.file_name_length, 1, 511 IGNORE_CASE, vol->upcase, vol->upcase_len); 512 /* 513 * If uname collates before the name of the current entry, there 514 * is definitely no such name in this index but we might need to 515 * descend into the B+tree so we just break out of the loop. 516 */ 517 if (rc == -1) 518 break; 519 /* The names are not equal, continue the search. */ 520 if (rc) 521 continue; 522 /* 523 * Names match with case insensitive comparison, now try the 524 * case sensitive comparison, which is required for proper 525 * collation. 526 */ 527 rc = ntfs_collate_names(uname, uname_len, 528 (ntfschar*)&ie->key.file_name.file_name, 529 ie->key.file_name.file_name_length, 1, 530 CASE_SENSITIVE, vol->upcase, vol->upcase_len); 531 if (rc == -1) 532 break; 533 if (rc) 534 continue; 535 /* 536 * Perfect match, this will never happen as the 537 * ntfs_are_names_equal() call will have gotten a match but we 538 * still treat it correctly. 539 */ 540 goto found_it2; 541 } 542 /* 543 * We have finished with this index buffer without success. Check for 544 * the presence of a child node. 545 */ 546 if (ie->flags & INDEX_ENTRY_NODE) { 547 if ((ia->index.flags & NODE_MASK) == LEAF_NODE) { 548 ntfs_error(sb, "Index entry with child node found in " 549 "a leaf node in directory inode 0x%lx.", 550 dir_ni->mft_no); 551 goto unm_err_out; 552 } 553 /* Child node present, descend into it. */ 554 old_vcn = vcn; 555 vcn = sle64_to_cpup((sle64*)((u8*)ie + 556 le16_to_cpu(ie->length) - 8)); 557 if (vcn >= 0) { 558 /* If vcn is in the same page cache page as old_vcn we 559 * recycle the mapped page. */ 560 if (old_vcn << vol->cluster_size_bits >> 561 PAGE_CACHE_SHIFT == vcn << 562 vol->cluster_size_bits >> 563 PAGE_CACHE_SHIFT) 564 goto fast_descend_into_child_node; 565 unlock_page(page); 566 ntfs_unmap_page(page); 567 goto descend_into_child_node; 568 } 569 ntfs_error(sb, "Negative child node vcn in directory inode " 570 "0x%lx.", dir_ni->mft_no); 571 goto unm_err_out; 572 } 573 /* 574 * No child node present, return -ENOENT, unless we have got a matching 575 * name cached in name in which case return the mft reference 576 * associated with it. 577 */ 578 if (name) { 579 unlock_page(page); 580 ntfs_unmap_page(page); 581 return name->mref; 582 } 583 ntfs_debug("Entry not found."); 584 err = -ENOENT; 585 unm_err_out: 586 unlock_page(page); 587 ntfs_unmap_page(page); 588 err_out: 589 if (!err) 590 err = -EIO; 591 if (ctx) 592 ntfs_attr_put_search_ctx(ctx); 593 if (m) 594 unmap_mft_record(dir_ni); 595 if (name) { 596 kfree(name); 597 *res = NULL; 598 } 599 return ERR_MREF(err); 600 dir_err_out: 601 ntfs_error(sb, "Corrupt directory. Aborting lookup."); 602 goto err_out; 603 } 604 605 #if 0 606 607 // TODO: (AIA) 608 // The algorithm embedded in this code will be required for the time when we 609 // want to support adding of entries to directories, where we require correct 610 // collation of file names in order not to cause corruption of the filesystem. 611 612 /** 613 * ntfs_lookup_inode_by_name - find an inode in a directory given its name 614 * @dir_ni: ntfs inode of the directory in which to search for the name 615 * @uname: Unicode name for which to search in the directory 616 * @uname_len: length of the name @uname in Unicode characters 617 * 618 * Look for an inode with name @uname in the directory with inode @dir_ni. 619 * ntfs_lookup_inode_by_name() walks the contents of the directory looking for 620 * the Unicode name. If the name is found in the directory, the corresponding 621 * inode number (>= 0) is returned as a mft reference in cpu format, i.e. it 622 * is a 64-bit number containing the sequence number. 623 * 624 * On error, a negative value is returned corresponding to the error code. In 625 * particular if the inode is not found -ENOENT is returned. Note that you 626 * can't just check the return value for being negative, you have to check the 627 * inode number for being negative which you can extract using MREC(return 628 * value). 629 * 630 * Note, @uname_len does not include the (optional) terminating NULL character. 631 */ 632 u64 ntfs_lookup_inode_by_name(ntfs_inode *dir_ni, const ntfschar *uname, 633 const int uname_len) 634 { 635 ntfs_volume *vol = dir_ni->vol; 636 struct super_block *sb = vol->sb; 637 MFT_RECORD *m; 638 INDEX_ROOT *ir; 639 INDEX_ENTRY *ie; 640 INDEX_ALLOCATION *ia; 641 u8 *index_end; 642 u64 mref; 643 ntfs_attr_search_ctx *ctx; 644 int err, rc; 645 IGNORE_CASE_BOOL ic; 646 VCN vcn, old_vcn; 647 struct address_space *ia_mapping; 648 struct page *page; 649 u8 *kaddr; 650 651 /* Get hold of the mft record for the directory. */ 652 m = map_mft_record(dir_ni); 653 if (IS_ERR(m)) { 654 ntfs_error(sb, "map_mft_record() failed with error code %ld.", 655 -PTR_ERR(m)); 656 return ERR_MREF(PTR_ERR(m)); 657 } 658 ctx = ntfs_attr_get_search_ctx(dir_ni, m); 659 if (!ctx) { 660 err = -ENOMEM; 661 goto err_out; 662 } 663 /* Find the index root attribute in the mft record. */ 664 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, 665 0, ctx); 666 if (unlikely(err)) { 667 if (err == -ENOENT) { 668 ntfs_error(sb, "Index root attribute missing in " 669 "directory inode 0x%lx.", 670 dir_ni->mft_no); 671 err = -EIO; 672 } 673 goto err_out; 674 } 675 /* Get to the index root value (it's been verified in read_inode). */ 676 ir = (INDEX_ROOT*)((u8*)ctx->attr + 677 le16_to_cpu(ctx->attr->data.resident.value_offset)); 678 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); 679 /* The first index entry. */ 680 ie = (INDEX_ENTRY*)((u8*)&ir->index + 681 le32_to_cpu(ir->index.entries_offset)); 682 /* 683 * Loop until we exceed valid memory (corruption case) or until we 684 * reach the last entry. 685 */ 686 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { 687 /* Bounds checks. */ 688 if ((u8*)ie < (u8*)ctx->mrec || (u8*)ie + 689 sizeof(INDEX_ENTRY_HEADER) > index_end || 690 (u8*)ie + le16_to_cpu(ie->key_length) > 691 index_end) 692 goto dir_err_out; 693 /* 694 * The last entry cannot contain a name. It can however contain 695 * a pointer to a child node in the B+tree so we just break out. 696 */ 697 if (ie->flags & INDEX_ENTRY_END) 698 break; 699 /* 700 * If the current entry has a name type of POSIX, the name is 701 * case sensitive and not otherwise. This has the effect of us 702 * not being able to access any POSIX file names which collate 703 * after the non-POSIX one when they only differ in case, but 704 * anyone doing screwy stuff like that deserves to burn in 705 * hell... Doing that kind of stuff on NT4 actually causes 706 * corruption on the partition even when using SP6a and Linux 707 * is not involved at all. 708 */ 709 ic = ie->key.file_name.file_name_type ? IGNORE_CASE : 710 CASE_SENSITIVE; 711 /* 712 * If the names match perfectly, we are done and return the 713 * mft reference of the inode (i.e. the inode number together 714 * with the sequence number for consistency checking. We 715 * convert it to cpu format before returning. 716 */ 717 if (ntfs_are_names_equal(uname, uname_len, 718 (ntfschar*)&ie->key.file_name.file_name, 719 ie->key.file_name.file_name_length, ic, 720 vol->upcase, vol->upcase_len)) { 721 found_it: 722 mref = le64_to_cpu(ie->data.dir.indexed_file); 723 ntfs_attr_put_search_ctx(ctx); 724 unmap_mft_record(dir_ni); 725 return mref; 726 } 727 /* 728 * Not a perfect match, need to do full blown collation so we 729 * know which way in the B+tree we have to go. 730 */ 731 rc = ntfs_collate_names(uname, uname_len, 732 (ntfschar*)&ie->key.file_name.file_name, 733 ie->key.file_name.file_name_length, 1, 734 IGNORE_CASE, vol->upcase, vol->upcase_len); 735 /* 736 * If uname collates before the name of the current entry, there 737 * is definitely no such name in this index but we might need to 738 * descend into the B+tree so we just break out of the loop. 739 */ 740 if (rc == -1) 741 break; 742 /* The names are not equal, continue the search. */ 743 if (rc) 744 continue; 745 /* 746 * Names match with case insensitive comparison, now try the 747 * case sensitive comparison, which is required for proper 748 * collation. 749 */ 750 rc = ntfs_collate_names(uname, uname_len, 751 (ntfschar*)&ie->key.file_name.file_name, 752 ie->key.file_name.file_name_length, 1, 753 CASE_SENSITIVE, vol->upcase, vol->upcase_len); 754 if (rc == -1) 755 break; 756 if (rc) 757 continue; 758 /* 759 * Perfect match, this will never happen as the 760 * ntfs_are_names_equal() call will have gotten a match but we 761 * still treat it correctly. 762 */ 763 goto found_it; 764 } 765 /* 766 * We have finished with this index without success. Check for the 767 * presence of a child node. 768 */ 769 if (!(ie->flags & INDEX_ENTRY_NODE)) { 770 /* No child node, return -ENOENT. */ 771 err = -ENOENT; 772 goto err_out; 773 } /* Child node present, descend into it. */ 774 /* Consistency check: Verify that an index allocation exists. */ 775 if (!NInoIndexAllocPresent(dir_ni)) { 776 ntfs_error(sb, "No index allocation attribute but index entry " 777 "requires one. Directory inode 0x%lx is " 778 "corrupt or driver bug.", dir_ni->mft_no); 779 goto err_out; 780 } 781 /* Get the starting vcn of the index_block holding the child node. */ 782 vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8); 783 ia_mapping = VFS_I(dir_ni)->i_mapping; 784 /* 785 * We are done with the index root and the mft record. Release them, 786 * otherwise we deadlock with ntfs_map_page(). 787 */ 788 ntfs_attr_put_search_ctx(ctx); 789 unmap_mft_record(dir_ni); 790 m = NULL; 791 ctx = NULL; 792 descend_into_child_node: 793 /* 794 * Convert vcn to index into the index allocation attribute in units 795 * of PAGE_CACHE_SIZE and map the page cache page, reading it from 796 * disk if necessary. 797 */ 798 page = ntfs_map_page(ia_mapping, vcn << 799 dir_ni->itype.index.vcn_size_bits >> PAGE_CACHE_SHIFT); 800 if (IS_ERR(page)) { 801 ntfs_error(sb, "Failed to map directory index page, error %ld.", 802 -PTR_ERR(page)); 803 err = PTR_ERR(page); 804 goto err_out; 805 } 806 lock_page(page); 807 kaddr = (u8*)page_address(page); 808 fast_descend_into_child_node: 809 /* Get to the index allocation block. */ 810 ia = (INDEX_ALLOCATION*)(kaddr + ((vcn << 811 dir_ni->itype.index.vcn_size_bits) & ~PAGE_CACHE_MASK)); 812 /* Bounds checks. */ 813 if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE) { 814 ntfs_error(sb, "Out of bounds check failed. Corrupt directory " 815 "inode 0x%lx or driver bug.", dir_ni->mft_no); 816 goto unm_err_out; 817 } 818 /* Catch multi sector transfer fixup errors. */ 819 if (unlikely(!ntfs_is_indx_record(ia->magic))) { 820 ntfs_error(sb, "Directory index record with vcn 0x%llx is " 821 "corrupt. Corrupt inode 0x%lx. Run chkdsk.", 822 (unsigned long long)vcn, dir_ni->mft_no); 823 goto unm_err_out; 824 } 825 if (sle64_to_cpu(ia->index_block_vcn) != vcn) { 826 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " 827 "different from expected VCN (0x%llx). " 828 "Directory inode 0x%lx is corrupt or driver " 829 "bug.", (unsigned long long) 830 sle64_to_cpu(ia->index_block_vcn), 831 (unsigned long long)vcn, dir_ni->mft_no); 832 goto unm_err_out; 833 } 834 if (le32_to_cpu(ia->index.allocated_size) + 0x18 != 835 dir_ni->itype.index.block_size) { 836 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " 837 "0x%lx has a size (%u) differing from the " 838 "directory specified size (%u). Directory " 839 "inode is corrupt or driver bug.", 840 (unsigned long long)vcn, dir_ni->mft_no, 841 le32_to_cpu(ia->index.allocated_size) + 0x18, 842 dir_ni->itype.index.block_size); 843 goto unm_err_out; 844 } 845 index_end = (u8*)ia + dir_ni->itype.index.block_size; 846 if (index_end > kaddr + PAGE_CACHE_SIZE) { 847 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " 848 "0x%lx crosses page boundary. Impossible! " 849 "Cannot access! This is probably a bug in the " 850 "driver.", (unsigned long long)vcn, 851 dir_ni->mft_no); 852 goto unm_err_out; 853 } 854 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); 855 if (index_end > (u8*)ia + dir_ni->itype.index.block_size) { 856 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " 857 "inode 0x%lx exceeds maximum size.", 858 (unsigned long long)vcn, dir_ni->mft_no); 859 goto unm_err_out; 860 } 861 /* The first index entry. */ 862 ie = (INDEX_ENTRY*)((u8*)&ia->index + 863 le32_to_cpu(ia->index.entries_offset)); 864 /* 865 * Iterate similar to above big loop but applied to index buffer, thus 866 * loop until we exceed valid memory (corruption case) or until we 867 * reach the last entry. 868 */ 869 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { 870 /* Bounds check. */ 871 if ((u8*)ie < (u8*)ia || (u8*)ie + 872 sizeof(INDEX_ENTRY_HEADER) > index_end || 873 (u8*)ie + le16_to_cpu(ie->key_length) > 874 index_end) { 875 ntfs_error(sb, "Index entry out of bounds in " 876 "directory inode 0x%lx.", 877 dir_ni->mft_no); 878 goto unm_err_out; 879 } 880 /* 881 * The last entry cannot contain a name. It can however contain 882 * a pointer to a child node in the B+tree so we just break out. 883 */ 884 if (ie->flags & INDEX_ENTRY_END) 885 break; 886 /* 887 * If the current entry has a name type of POSIX, the name is 888 * case sensitive and not otherwise. This has the effect of us 889 * not being able to access any POSIX file names which collate 890 * after the non-POSIX one when they only differ in case, but 891 * anyone doing screwy stuff like that deserves to burn in 892 * hell... Doing that kind of stuff on NT4 actually causes 893 * corruption on the partition even when using SP6a and Linux 894 * is not involved at all. 895 */ 896 ic = ie->key.file_name.file_name_type ? IGNORE_CASE : 897 CASE_SENSITIVE; 898 /* 899 * If the names match perfectly, we are done and return the 900 * mft reference of the inode (i.e. the inode number together 901 * with the sequence number for consistency checking. We 902 * convert it to cpu format before returning. 903 */ 904 if (ntfs_are_names_equal(uname, uname_len, 905 (ntfschar*)&ie->key.file_name.file_name, 906 ie->key.file_name.file_name_length, ic, 907 vol->upcase, vol->upcase_len)) { 908 found_it2: 909 mref = le64_to_cpu(ie->data.dir.indexed_file); 910 unlock_page(page); 911 ntfs_unmap_page(page); 912 return mref; 913 } 914 /* 915 * Not a perfect match, need to do full blown collation so we 916 * know which way in the B+tree we have to go. 917 */ 918 rc = ntfs_collate_names(uname, uname_len, 919 (ntfschar*)&ie->key.file_name.file_name, 920 ie->key.file_name.file_name_length, 1, 921 IGNORE_CASE, vol->upcase, vol->upcase_len); 922 /* 923 * If uname collates before the name of the current entry, there 924 * is definitely no such name in this index but we might need to 925 * descend into the B+tree so we just break out of the loop. 926 */ 927 if (rc == -1) 928 break; 929 /* The names are not equal, continue the search. */ 930 if (rc) 931 continue; 932 /* 933 * Names match with case insensitive comparison, now try the 934 * case sensitive comparison, which is required for proper 935 * collation. 936 */ 937 rc = ntfs_collate_names(uname, uname_len, 938 (ntfschar*)&ie->key.file_name.file_name, 939 ie->key.file_name.file_name_length, 1, 940 CASE_SENSITIVE, vol->upcase, vol->upcase_len); 941 if (rc == -1) 942 break; 943 if (rc) 944 continue; 945 /* 946 * Perfect match, this will never happen as the 947 * ntfs_are_names_equal() call will have gotten a match but we 948 * still treat it correctly. 949 */ 950 goto found_it2; 951 } 952 /* 953 * We have finished with this index buffer without success. Check for 954 * the presence of a child node. 955 */ 956 if (ie->flags & INDEX_ENTRY_NODE) { 957 if ((ia->index.flags & NODE_MASK) == LEAF_NODE) { 958 ntfs_error(sb, "Index entry with child node found in " 959 "a leaf node in directory inode 0x%lx.", 960 dir_ni->mft_no); 961 goto unm_err_out; 962 } 963 /* Child node present, descend into it. */ 964 old_vcn = vcn; 965 vcn = sle64_to_cpup((u8*)ie + le16_to_cpu(ie->length) - 8); 966 if (vcn >= 0) { 967 /* If vcn is in the same page cache page as old_vcn we 968 * recycle the mapped page. */ 969 if (old_vcn << vol->cluster_size_bits >> 970 PAGE_CACHE_SHIFT == vcn << 971 vol->cluster_size_bits >> 972 PAGE_CACHE_SHIFT) 973 goto fast_descend_into_child_node; 974 unlock_page(page); 975 ntfs_unmap_page(page); 976 goto descend_into_child_node; 977 } 978 ntfs_error(sb, "Negative child node vcn in directory inode " 979 "0x%lx.", dir_ni->mft_no); 980 goto unm_err_out; 981 } 982 /* No child node, return -ENOENT. */ 983 ntfs_debug("Entry not found."); 984 err = -ENOENT; 985 unm_err_out: 986 unlock_page(page); 987 ntfs_unmap_page(page); 988 err_out: 989 if (!err) 990 err = -EIO; 991 if (ctx) 992 ntfs_attr_put_search_ctx(ctx); 993 if (m) 994 unmap_mft_record(dir_ni); 995 return ERR_MREF(err); 996 dir_err_out: 997 ntfs_error(sb, "Corrupt directory. Aborting lookup."); 998 goto err_out; 999 } 1000 1001 #endif 1002 1003 /** 1004 * ntfs_filldir - ntfs specific filldir method 1005 * @vol: current ntfs volume 1006 * @fpos: position in the directory 1007 * @ndir: ntfs inode of current directory 1008 * @ia_page: page in which the index allocation buffer @ie is in resides 1009 * @ie: current index entry 1010 * @name: buffer to use for the converted name 1011 * @dirent: vfs filldir callback context 1012 * @filldir: vfs filldir callback 1013 * 1014 * Convert the Unicode @name to the loaded NLS and pass it to the @filldir 1015 * callback. 1016 * 1017 * If @ia_page is not NULL it is the locked page containing the index 1018 * allocation block containing the index entry @ie. 1019 * 1020 * Note, we drop (and then reacquire) the page lock on @ia_page across the 1021 * @filldir() call otherwise we would deadlock with NFSd when it calls ->lookup 1022 * since ntfs_lookup() will lock the same page. As an optimization, we do not 1023 * retake the lock if we are returning a non-zero value as ntfs_readdir() 1024 * would need to drop the lock immediately anyway. 1025 */ 1026 static inline int ntfs_filldir(ntfs_volume *vol, loff_t fpos, 1027 ntfs_inode *ndir, struct page *ia_page, INDEX_ENTRY *ie, 1028 u8 *name, void *dirent, filldir_t filldir) 1029 { 1030 unsigned long mref; 1031 int name_len, rc; 1032 unsigned dt_type; 1033 FILE_NAME_TYPE_FLAGS name_type; 1034 1035 name_type = ie->key.file_name.file_name_type; 1036 if (name_type == FILE_NAME_DOS) { 1037 ntfs_debug("Skipping DOS name space entry."); 1038 return 0; 1039 } 1040 if (MREF_LE(ie->data.dir.indexed_file) == FILE_root) { 1041 ntfs_debug("Skipping root directory self reference entry."); 1042 return 0; 1043 } 1044 if (MREF_LE(ie->data.dir.indexed_file) < FILE_first_user && 1045 !NVolShowSystemFiles(vol)) { 1046 ntfs_debug("Skipping system file."); 1047 return 0; 1048 } 1049 name_len = ntfs_ucstonls(vol, (ntfschar*)&ie->key.file_name.file_name, 1050 ie->key.file_name.file_name_length, &name, 1051 NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1); 1052 if (name_len <= 0) { 1053 ntfs_warning(vol->sb, "Skipping unrepresentable inode 0x%llx.", 1054 (long long)MREF_LE(ie->data.dir.indexed_file)); 1055 return 0; 1056 } 1057 if (ie->key.file_name.file_attributes & 1058 FILE_ATTR_DUP_FILE_NAME_INDEX_PRESENT) 1059 dt_type = DT_DIR; 1060 else 1061 dt_type = DT_REG; 1062 mref = MREF_LE(ie->data.dir.indexed_file); 1063 /* 1064 * Drop the page lock otherwise we deadlock with NFS when it calls 1065 * ->lookup since ntfs_lookup() will lock the same page. 1066 */ 1067 if (ia_page) 1068 unlock_page(ia_page); 1069 ntfs_debug("Calling filldir for %s with len %i, fpos 0x%llx, inode " 1070 "0x%lx, DT_%s.", name, name_len, fpos, mref, 1071 dt_type == DT_DIR ? "DIR" : "REG"); 1072 rc = filldir(dirent, name, name_len, fpos, mref, dt_type); 1073 /* Relock the page but not if we are aborting ->readdir. */ 1074 if (!rc && ia_page) 1075 lock_page(ia_page); 1076 return rc; 1077 } 1078 1079 /* 1080 * We use the same basic approach as the old NTFS driver, i.e. we parse the 1081 * index root entries and then the index allocation entries that are marked 1082 * as in use in the index bitmap. 1083 * 1084 * While this will return the names in random order this doesn't matter for 1085 * ->readdir but OTOH results in a faster ->readdir. 1086 * 1087 * VFS calls ->readdir without BKL but with i_mutex held. This protects the VFS 1088 * parts (e.g. ->f_pos and ->i_size, and it also protects against directory 1089 * modifications). 1090 * 1091 * Locking: - Caller must hold i_mutex on the directory. 1092 * - Each page cache page in the index allocation mapping must be 1093 * locked whilst being accessed otherwise we may find a corrupt 1094 * page due to it being under ->writepage at the moment which 1095 * applies the mst protection fixups before writing out and then 1096 * removes them again after the write is complete after which it 1097 * unlocks the page. 1098 */ 1099 static int ntfs_readdir(struct file *filp, void *dirent, filldir_t filldir) 1100 { 1101 s64 ia_pos, ia_start, prev_ia_pos, bmp_pos; 1102 loff_t fpos, i_size; 1103 struct inode *bmp_vi, *vdir = filp->f_path.dentry->d_inode; 1104 struct super_block *sb = vdir->i_sb; 1105 ntfs_inode *ndir = NTFS_I(vdir); 1106 ntfs_volume *vol = NTFS_SB(sb); 1107 MFT_RECORD *m; 1108 INDEX_ROOT *ir = NULL; 1109 INDEX_ENTRY *ie; 1110 INDEX_ALLOCATION *ia; 1111 u8 *name = NULL; 1112 int rc, err, ir_pos, cur_bmp_pos; 1113 struct address_space *ia_mapping, *bmp_mapping; 1114 struct page *bmp_page = NULL, *ia_page = NULL; 1115 u8 *kaddr, *bmp, *index_end; 1116 ntfs_attr_search_ctx *ctx; 1117 1118 fpos = filp->f_pos; 1119 ntfs_debug("Entering for inode 0x%lx, fpos 0x%llx.", 1120 vdir->i_ino, fpos); 1121 rc = err = 0; 1122 /* Are we at end of dir yet? */ 1123 i_size = i_size_read(vdir); 1124 if (fpos >= i_size + vol->mft_record_size) 1125 goto done; 1126 /* Emulate . and .. for all directories. */ 1127 if (!fpos) { 1128 ntfs_debug("Calling filldir for . with len 1, fpos 0x0, " 1129 "inode 0x%lx, DT_DIR.", vdir->i_ino); 1130 rc = filldir(dirent, ".", 1, fpos, vdir->i_ino, DT_DIR); 1131 if (rc) 1132 goto done; 1133 fpos++; 1134 } 1135 if (fpos == 1) { 1136 ntfs_debug("Calling filldir for .. with len 2, fpos 0x1, " 1137 "inode 0x%lx, DT_DIR.", 1138 (unsigned long)parent_ino(filp->f_path.dentry)); 1139 rc = filldir(dirent, "..", 2, fpos, 1140 parent_ino(filp->f_path.dentry), DT_DIR); 1141 if (rc) 1142 goto done; 1143 fpos++; 1144 } 1145 m = NULL; 1146 ctx = NULL; 1147 /* 1148 * Allocate a buffer to store the current name being processed 1149 * converted to format determined by current NLS. 1150 */ 1151 name = kmalloc(NTFS_MAX_NAME_LEN * NLS_MAX_CHARSET_SIZE + 1, GFP_NOFS); 1152 if (unlikely(!name)) { 1153 err = -ENOMEM; 1154 goto err_out; 1155 } 1156 /* Are we jumping straight into the index allocation attribute? */ 1157 if (fpos >= vol->mft_record_size) 1158 goto skip_index_root; 1159 /* Get hold of the mft record for the directory. */ 1160 m = map_mft_record(ndir); 1161 if (IS_ERR(m)) { 1162 err = PTR_ERR(m); 1163 m = NULL; 1164 goto err_out; 1165 } 1166 ctx = ntfs_attr_get_search_ctx(ndir, m); 1167 if (unlikely(!ctx)) { 1168 err = -ENOMEM; 1169 goto err_out; 1170 } 1171 /* Get the offset into the index root attribute. */ 1172 ir_pos = (s64)fpos; 1173 /* Find the index root attribute in the mft record. */ 1174 err = ntfs_attr_lookup(AT_INDEX_ROOT, I30, 4, CASE_SENSITIVE, 0, NULL, 1175 0, ctx); 1176 if (unlikely(err)) { 1177 ntfs_error(sb, "Index root attribute missing in directory " 1178 "inode 0x%lx.", vdir->i_ino); 1179 goto err_out; 1180 } 1181 /* 1182 * Copy the index root attribute value to a buffer so that we can put 1183 * the search context and unmap the mft record before calling the 1184 * filldir() callback. We need to do this because of NFSd which calls 1185 * ->lookup() from its filldir callback() and this causes NTFS to 1186 * deadlock as ntfs_lookup() maps the mft record of the directory and 1187 * we have got it mapped here already. The only solution is for us to 1188 * unmap the mft record here so that a call to ntfs_lookup() is able to 1189 * map the mft record without deadlocking. 1190 */ 1191 rc = le32_to_cpu(ctx->attr->data.resident.value_length); 1192 ir = kmalloc(rc, GFP_NOFS); 1193 if (unlikely(!ir)) { 1194 err = -ENOMEM; 1195 goto err_out; 1196 } 1197 /* Copy the index root value (it has been verified in read_inode). */ 1198 memcpy(ir, (u8*)ctx->attr + 1199 le16_to_cpu(ctx->attr->data.resident.value_offset), rc); 1200 ntfs_attr_put_search_ctx(ctx); 1201 unmap_mft_record(ndir); 1202 ctx = NULL; 1203 m = NULL; 1204 index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length); 1205 /* The first index entry. */ 1206 ie = (INDEX_ENTRY*)((u8*)&ir->index + 1207 le32_to_cpu(ir->index.entries_offset)); 1208 /* 1209 * Loop until we exceed valid memory (corruption case) or until we 1210 * reach the last entry or until filldir tells us it has had enough 1211 * or signals an error (both covered by the rc test). 1212 */ 1213 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { 1214 ntfs_debug("In index root, offset 0x%zx.", (u8*)ie - (u8*)ir); 1215 /* Bounds checks. */ 1216 if (unlikely((u8*)ie < (u8*)ir || (u8*)ie + 1217 sizeof(INDEX_ENTRY_HEADER) > index_end || 1218 (u8*)ie + le16_to_cpu(ie->key_length) > 1219 index_end)) 1220 goto err_out; 1221 /* The last entry cannot contain a name. */ 1222 if (ie->flags & INDEX_ENTRY_END) 1223 break; 1224 /* Skip index root entry if continuing previous readdir. */ 1225 if (ir_pos > (u8*)ie - (u8*)ir) 1226 continue; 1227 /* Advance the position even if going to skip the entry. */ 1228 fpos = (u8*)ie - (u8*)ir; 1229 /* Submit the name to the filldir callback. */ 1230 rc = ntfs_filldir(vol, fpos, ndir, NULL, ie, name, dirent, 1231 filldir); 1232 if (rc) { 1233 kfree(ir); 1234 goto abort; 1235 } 1236 } 1237 /* We are done with the index root and can free the buffer. */ 1238 kfree(ir); 1239 ir = NULL; 1240 /* If there is no index allocation attribute we are finished. */ 1241 if (!NInoIndexAllocPresent(ndir)) 1242 goto EOD; 1243 /* Advance fpos to the beginning of the index allocation. */ 1244 fpos = vol->mft_record_size; 1245 skip_index_root: 1246 kaddr = NULL; 1247 prev_ia_pos = -1LL; 1248 /* Get the offset into the index allocation attribute. */ 1249 ia_pos = (s64)fpos - vol->mft_record_size; 1250 ia_mapping = vdir->i_mapping; 1251 ntfs_debug("Inode 0x%lx, getting index bitmap.", vdir->i_ino); 1252 bmp_vi = ntfs_attr_iget(vdir, AT_BITMAP, I30, 4); 1253 if (IS_ERR(bmp_vi)) { 1254 ntfs_error(sb, "Failed to get bitmap attribute."); 1255 err = PTR_ERR(bmp_vi); 1256 goto err_out; 1257 } 1258 bmp_mapping = bmp_vi->i_mapping; 1259 /* Get the starting bitmap bit position and sanity check it. */ 1260 bmp_pos = ia_pos >> ndir->itype.index.block_size_bits; 1261 if (unlikely(bmp_pos >> 3 >= i_size_read(bmp_vi))) { 1262 ntfs_error(sb, "Current index allocation position exceeds " 1263 "index bitmap size."); 1264 goto iput_err_out; 1265 } 1266 /* Get the starting bit position in the current bitmap page. */ 1267 cur_bmp_pos = bmp_pos & ((PAGE_CACHE_SIZE * 8) - 1); 1268 bmp_pos &= ~(u64)((PAGE_CACHE_SIZE * 8) - 1); 1269 get_next_bmp_page: 1270 ntfs_debug("Reading bitmap with page index 0x%llx, bit ofs 0x%llx", 1271 (unsigned long long)bmp_pos >> (3 + PAGE_CACHE_SHIFT), 1272 (unsigned long long)bmp_pos & 1273 (unsigned long long)((PAGE_CACHE_SIZE * 8) - 1)); 1274 bmp_page = ntfs_map_page(bmp_mapping, 1275 bmp_pos >> (3 + PAGE_CACHE_SHIFT)); 1276 if (IS_ERR(bmp_page)) { 1277 ntfs_error(sb, "Reading index bitmap failed."); 1278 err = PTR_ERR(bmp_page); 1279 bmp_page = NULL; 1280 goto iput_err_out; 1281 } 1282 bmp = (u8*)page_address(bmp_page); 1283 /* Find next index block in use. */ 1284 while (!(bmp[cur_bmp_pos >> 3] & (1 << (cur_bmp_pos & 7)))) { 1285 find_next_index_buffer: 1286 cur_bmp_pos++; 1287 /* 1288 * If we have reached the end of the bitmap page, get the next 1289 * page, and put away the old one. 1290 */ 1291 if (unlikely((cur_bmp_pos >> 3) >= PAGE_CACHE_SIZE)) { 1292 ntfs_unmap_page(bmp_page); 1293 bmp_pos += PAGE_CACHE_SIZE * 8; 1294 cur_bmp_pos = 0; 1295 goto get_next_bmp_page; 1296 } 1297 /* If we have reached the end of the bitmap, we are done. */ 1298 if (unlikely(((bmp_pos + cur_bmp_pos) >> 3) >= i_size)) 1299 goto unm_EOD; 1300 ia_pos = (bmp_pos + cur_bmp_pos) << 1301 ndir->itype.index.block_size_bits; 1302 } 1303 ntfs_debug("Handling index buffer 0x%llx.", 1304 (unsigned long long)bmp_pos + cur_bmp_pos); 1305 /* If the current index buffer is in the same page we reuse the page. */ 1306 if ((prev_ia_pos & (s64)PAGE_CACHE_MASK) != 1307 (ia_pos & (s64)PAGE_CACHE_MASK)) { 1308 prev_ia_pos = ia_pos; 1309 if (likely(ia_page != NULL)) { 1310 unlock_page(ia_page); 1311 ntfs_unmap_page(ia_page); 1312 } 1313 /* 1314 * Map the page cache page containing the current ia_pos, 1315 * reading it from disk if necessary. 1316 */ 1317 ia_page = ntfs_map_page(ia_mapping, ia_pos >> PAGE_CACHE_SHIFT); 1318 if (IS_ERR(ia_page)) { 1319 ntfs_error(sb, "Reading index allocation data failed."); 1320 err = PTR_ERR(ia_page); 1321 ia_page = NULL; 1322 goto err_out; 1323 } 1324 lock_page(ia_page); 1325 kaddr = (u8*)page_address(ia_page); 1326 } 1327 /* Get the current index buffer. */ 1328 ia = (INDEX_ALLOCATION*)(kaddr + (ia_pos & ~PAGE_CACHE_MASK & 1329 ~(s64)(ndir->itype.index.block_size - 1))); 1330 /* Bounds checks. */ 1331 if (unlikely((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE)) { 1332 ntfs_error(sb, "Out of bounds check failed. Corrupt directory " 1333 "inode 0x%lx or driver bug.", vdir->i_ino); 1334 goto err_out; 1335 } 1336 /* Catch multi sector transfer fixup errors. */ 1337 if (unlikely(!ntfs_is_indx_record(ia->magic))) { 1338 ntfs_error(sb, "Directory index record with vcn 0x%llx is " 1339 "corrupt. Corrupt inode 0x%lx. Run chkdsk.", 1340 (unsigned long long)ia_pos >> 1341 ndir->itype.index.vcn_size_bits, vdir->i_ino); 1342 goto err_out; 1343 } 1344 if (unlikely(sle64_to_cpu(ia->index_block_vcn) != (ia_pos & 1345 ~(s64)(ndir->itype.index.block_size - 1)) >> 1346 ndir->itype.index.vcn_size_bits)) { 1347 ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is " 1348 "different from expected VCN (0x%llx). " 1349 "Directory inode 0x%lx is corrupt or driver " 1350 "bug. ", (unsigned long long) 1351 sle64_to_cpu(ia->index_block_vcn), 1352 (unsigned long long)ia_pos >> 1353 ndir->itype.index.vcn_size_bits, vdir->i_ino); 1354 goto err_out; 1355 } 1356 if (unlikely(le32_to_cpu(ia->index.allocated_size) + 0x18 != 1357 ndir->itype.index.block_size)) { 1358 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " 1359 "0x%lx has a size (%u) differing from the " 1360 "directory specified size (%u). Directory " 1361 "inode is corrupt or driver bug.", 1362 (unsigned long long)ia_pos >> 1363 ndir->itype.index.vcn_size_bits, vdir->i_ino, 1364 le32_to_cpu(ia->index.allocated_size) + 0x18, 1365 ndir->itype.index.block_size); 1366 goto err_out; 1367 } 1368 index_end = (u8*)ia + ndir->itype.index.block_size; 1369 if (unlikely(index_end > kaddr + PAGE_CACHE_SIZE)) { 1370 ntfs_error(sb, "Index buffer (VCN 0x%llx) of directory inode " 1371 "0x%lx crosses page boundary. Impossible! " 1372 "Cannot access! This is probably a bug in the " 1373 "driver.", (unsigned long long)ia_pos >> 1374 ndir->itype.index.vcn_size_bits, vdir->i_ino); 1375 goto err_out; 1376 } 1377 ia_start = ia_pos & ~(s64)(ndir->itype.index.block_size - 1); 1378 index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length); 1379 if (unlikely(index_end > (u8*)ia + ndir->itype.index.block_size)) { 1380 ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of directory " 1381 "inode 0x%lx exceeds maximum size.", 1382 (unsigned long long)ia_pos >> 1383 ndir->itype.index.vcn_size_bits, vdir->i_ino); 1384 goto err_out; 1385 } 1386 /* The first index entry in this index buffer. */ 1387 ie = (INDEX_ENTRY*)((u8*)&ia->index + 1388 le32_to_cpu(ia->index.entries_offset)); 1389 /* 1390 * Loop until we exceed valid memory (corruption case) or until we 1391 * reach the last entry or until filldir tells us it has had enough 1392 * or signals an error (both covered by the rc test). 1393 */ 1394 for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) { 1395 ntfs_debug("In index allocation, offset 0x%llx.", 1396 (unsigned long long)ia_start + 1397 (unsigned long long)((u8*)ie - (u8*)ia)); 1398 /* Bounds checks. */ 1399 if (unlikely((u8*)ie < (u8*)ia || (u8*)ie + 1400 sizeof(INDEX_ENTRY_HEADER) > index_end || 1401 (u8*)ie + le16_to_cpu(ie->key_length) > 1402 index_end)) 1403 goto err_out; 1404 /* The last entry cannot contain a name. */ 1405 if (ie->flags & INDEX_ENTRY_END) 1406 break; 1407 /* Skip index block entry if continuing previous readdir. */ 1408 if (ia_pos - ia_start > (u8*)ie - (u8*)ia) 1409 continue; 1410 /* Advance the position even if going to skip the entry. */ 1411 fpos = (u8*)ie - (u8*)ia + 1412 (sle64_to_cpu(ia->index_block_vcn) << 1413 ndir->itype.index.vcn_size_bits) + 1414 vol->mft_record_size; 1415 /* 1416 * Submit the name to the @filldir callback. Note, 1417 * ntfs_filldir() drops the lock on @ia_page but it retakes it 1418 * before returning, unless a non-zero value is returned in 1419 * which case the page is left unlocked. 1420 */ 1421 rc = ntfs_filldir(vol, fpos, ndir, ia_page, ie, name, dirent, 1422 filldir); 1423 if (rc) { 1424 /* @ia_page is already unlocked in this case. */ 1425 ntfs_unmap_page(ia_page); 1426 ntfs_unmap_page(bmp_page); 1427 iput(bmp_vi); 1428 goto abort; 1429 } 1430 } 1431 goto find_next_index_buffer; 1432 unm_EOD: 1433 if (ia_page) { 1434 unlock_page(ia_page); 1435 ntfs_unmap_page(ia_page); 1436 } 1437 ntfs_unmap_page(bmp_page); 1438 iput(bmp_vi); 1439 EOD: 1440 /* We are finished, set fpos to EOD. */ 1441 fpos = i_size + vol->mft_record_size; 1442 abort: 1443 kfree(name); 1444 done: 1445 #ifdef DEBUG 1446 if (!rc) 1447 ntfs_debug("EOD, fpos 0x%llx, returning 0.", fpos); 1448 else 1449 ntfs_debug("filldir returned %i, fpos 0x%llx, returning 0.", 1450 rc, fpos); 1451 #endif 1452 filp->f_pos = fpos; 1453 return 0; 1454 err_out: 1455 if (bmp_page) { 1456 ntfs_unmap_page(bmp_page); 1457 iput_err_out: 1458 iput(bmp_vi); 1459 } 1460 if (ia_page) { 1461 unlock_page(ia_page); 1462 ntfs_unmap_page(ia_page); 1463 } 1464 kfree(ir); 1465 kfree(name); 1466 if (ctx) 1467 ntfs_attr_put_search_ctx(ctx); 1468 if (m) 1469 unmap_mft_record(ndir); 1470 if (!err) 1471 err = -EIO; 1472 ntfs_debug("Failed. Returning error code %i.", -err); 1473 filp->f_pos = fpos; 1474 return err; 1475 } 1476 1477 /** 1478 * ntfs_dir_open - called when an inode is about to be opened 1479 * @vi: inode to be opened 1480 * @filp: file structure describing the inode 1481 * 1482 * Limit directory size to the page cache limit on architectures where unsigned 1483 * long is 32-bits. This is the most we can do for now without overflowing the 1484 * page cache page index. Doing it this way means we don't run into problems 1485 * because of existing too large directories. It would be better to allow the 1486 * user to read the accessible part of the directory but I doubt very much 1487 * anyone is going to hit this check on a 32-bit architecture, so there is no 1488 * point in adding the extra complexity required to support this. 1489 * 1490 * On 64-bit architectures, the check is hopefully optimized away by the 1491 * compiler. 1492 */ 1493 static int ntfs_dir_open(struct inode *vi, struct file *filp) 1494 { 1495 if (sizeof(unsigned long) < 8) { 1496 if (i_size_read(vi) > MAX_LFS_FILESIZE) 1497 return -EFBIG; 1498 } 1499 return 0; 1500 } 1501 1502 #ifdef NTFS_RW 1503 1504 /** 1505 * ntfs_dir_fsync - sync a directory to disk 1506 * @filp: directory to be synced 1507 * @dentry: dentry describing the directory to sync 1508 * @datasync: if non-zero only flush user data and not metadata 1509 * 1510 * Data integrity sync of a directory to disk. Used for fsync, fdatasync, and 1511 * msync system calls. This function is based on file.c::ntfs_file_fsync(). 1512 * 1513 * Write the mft record and all associated extent mft records as well as the 1514 * $INDEX_ALLOCATION and $BITMAP attributes and then sync the block device. 1515 * 1516 * If @datasync is true, we do not wait on the inode(s) to be written out 1517 * but we always wait on the page cache pages to be written out. 1518 * 1519 * Note: In the past @filp could be NULL so we ignore it as we don't need it 1520 * anyway. 1521 * 1522 * Locking: Caller must hold i_mutex on the inode. 1523 * 1524 * TODO: We should probably also write all attribute/index inodes associated 1525 * with this inode but since we have no simple way of getting to them we ignore 1526 * this problem for now. We do write the $BITMAP attribute if it is present 1527 * which is the important one for a directory so things are not too bad. 1528 */ 1529 static int ntfs_dir_fsync(struct file *filp, struct dentry *dentry, 1530 int datasync) 1531 { 1532 struct inode *bmp_vi, *vi = dentry->d_inode; 1533 int err, ret; 1534 ntfs_attr na; 1535 1536 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); 1537 BUG_ON(!S_ISDIR(vi->i_mode)); 1538 /* If the bitmap attribute inode is in memory sync it, too. */ 1539 na.mft_no = vi->i_ino; 1540 na.type = AT_BITMAP; 1541 na.name = I30; 1542 na.name_len = 4; 1543 bmp_vi = ilookup5(vi->i_sb, vi->i_ino, (test_t)ntfs_test_inode, &na); 1544 if (bmp_vi) { 1545 write_inode_now(bmp_vi, !datasync); 1546 iput(bmp_vi); 1547 } 1548 ret = ntfs_write_inode(vi, 1); 1549 write_inode_now(vi, !datasync); 1550 err = sync_blockdev(vi->i_sb->s_bdev); 1551 if (unlikely(err && !ret)) 1552 ret = err; 1553 if (likely(!ret)) 1554 ntfs_debug("Done."); 1555 else 1556 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error " 1557 "%u.", datasync ? "data" : "", vi->i_ino, -ret); 1558 return ret; 1559 } 1560 1561 #endif /* NTFS_RW */ 1562 1563 const struct file_operations ntfs_dir_ops = { 1564 .llseek = generic_file_llseek, /* Seek inside directory. */ 1565 .read = generic_read_dir, /* Return -EISDIR. */ 1566 .readdir = ntfs_readdir, /* Read directory contents. */ 1567 #ifdef NTFS_RW 1568 .fsync = ntfs_dir_fsync, /* Sync a directory to disk. */ 1569 /*.aio_fsync = ,*/ /* Sync all outstanding async 1570 i/o operations on a kiocb. */ 1571 #endif /* NTFS_RW */ 1572 /*.ioctl = ,*/ /* Perform function on the 1573 mounted filesystem. */ 1574 .open = ntfs_dir_open, /* Open directory. */ 1575 }; 1576