pass2.c revision 21c84b71e205b5ab13f14343da5645dcc985856d
1/* 2 * pass2.c --- check directory structure 3 * 4 * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o 5 * 6 * %Begin-Header% 7 * This file may be redistributed under the terms of the GNU Public 8 * License. 9 * %End-Header% 10 * 11 * Pass 2 of e2fsck iterates through all active directory inodes, and 12 * applies to following tests to each directory entry in the directory 13 * blocks in the inodes: 14 * 15 * - The length of the directory entry (rec_len) should be at 16 * least 8 bytes, and no more than the remaining space 17 * left in the directory block. 18 * - The length of the name in the directory entry (name_len) 19 * should be less than (rec_len - 8). 20 * - The inode number in the directory entry should be within 21 * legal bounds. 22 * - The inode number should refer to a in-use inode. 23 * - The first entry should be '.', and its inode should be 24 * the inode of the directory. 25 * - The second entry should be '..'. 26 * 27 * To minimize disk seek time, the directory blocks are processed in 28 * sorted order of block numbers. 29 * 30 * Pass 2 also collects the following information: 31 * - The inode numbers of the subdirectories for each directory. 32 * 33 * Pass 2 relies on the following information from previous passes: 34 * - The directory information collected in pass 1. 35 * - The inode_used_map bitmap 36 * - The inode_bad_map bitmap 37 * - The inode_dir_map bitmap 38 * 39 * Pass 2 frees the following data structures 40 * - The inode_bad_map bitmap 41 */ 42 43#include "et/com_err.h" 44 45#include "e2fsck.h" 46#include "problem.h" 47 48/* 49 * Keeps track of how many times an inode is referenced. 50 */ 51ext2_icount_t inode_count = 0; 52 53static void deallocate_inode(ext2_filsys fs, ino_t ino, 54 char* block_buf); 55static int process_bad_inode(ext2_filsys fs, ino_t dir, ino_t ino); 56static int check_dir_block(ext2_filsys fs, 57 struct ext2_db_entry *dir_blocks_info, 58 void *private); 59static int allocate_dir_block(ext2_filsys fs, 60 struct ext2_db_entry *dir_blocks_info, 61 char *buf, struct problem_context *pctx); 62static int update_dir_block(ext2_filsys fs, 63 blk_t *block_nr, 64 int blockcnt, 65 void *private); 66 67struct check_dir_struct { 68 char *buf; 69 struct problem_context pctx; 70}; 71 72void pass2(ext2_filsys fs) 73{ 74 char *buf; 75 struct resource_track rtrack; 76 struct dir_info *dir; 77 errcode_t retval; 78 ino_t size; 79 struct check_dir_struct cd; 80 81 init_resource_track(&rtrack); 82 83#ifdef MTRACE 84 mtrace_print("Pass 2"); 85#endif 86 87 if (!preen) 88 printf("Pass 2: Checking directory structure\n"); 89 size = ext2fs_get_icount_size(inode_link_info) + 10; 90 retval = ext2fs_create_icount(fs, EXT2_ICOUNT_OPT_INCREMENT, 91 size, &inode_count); 92 if (retval) { 93 com_err("ext2fs_create_icount", retval, 94 "while creating inode_count"); 95 fatal_error(0); 96 } 97 buf = allocate_memory(fs->blocksize, "directory scan buffer"); 98 99 /* 100 * Set up the parent pointer for the root directory, if 101 * present. (If the root directory is not present, we will 102 * create it in pass 3.) 103 */ 104 dir = get_dir_info(EXT2_ROOT_INO); 105 if (dir) 106 dir->parent = EXT2_ROOT_INO; 107 108 cd.buf = buf; 109 clear_problem_context(&cd.pctx); 110 111 retval = ext2fs_dblist_iterate(fs->dblist, check_dir_block, &cd); 112 113 free(buf); 114 ext2fs_free_dblist(fs->dblist); 115 116 if (inode_bad_map) { 117 ext2fs_free_inode_bitmap(inode_bad_map); 118 inode_bad_map = 0; 119 } 120 if (tflag > 1) { 121 printf("Pass 2: "); 122 print_resource_track(&rtrack); 123 } 124} 125 126/* 127 * Make sure the first entry in the directory is '.', and that the 128 * directory entry is sane. 129 */ 130static int check_dot(ext2_filsys fs, 131 struct ext2_dir_entry *dirent, 132 ino_t ino, struct problem_context *pctx) 133{ 134 struct ext2_dir_entry *nextdir; 135 int status = 0; 136 int created = 0; 137 int new_len; 138 int problem = 0; 139 140 if (!dirent->inode) 141 problem = PR_2_MISSING_DOT; 142 else if ((dirent->name_len != 1) || 143 (dirent->name[0] != '.')) 144 problem = PR_2_1ST_NOT_DOT; 145 else if (dirent->name[1] != '\0') 146 problem = PR_2_DOT_NULL_TERM; 147 148 if (problem) { 149 if (fix_problem(fs, problem, pctx)) { 150 if (dirent->rec_len < 12) 151 dirent->rec_len = 12; 152 dirent->inode = ino; 153 dirent->name_len = 1; 154 dirent->name[0] = '.'; 155 dirent->name[1] = '\0'; 156 status = 1; 157 created = 1; 158 } 159 } 160 if (dirent->inode != ino) { 161 if (fix_problem(fs, PR_2_BAD_INODE_DOT, pctx)) { 162 dirent->inode = ino; 163 status = 1; 164 } 165 } 166 if (dirent->rec_len > 12) { 167 new_len = dirent->rec_len - 12; 168 if (new_len > 12) { 169 preenhalt(fs); 170 if (created || 171 ask("Directory entry for '.' is big. Split", 1)) { 172 nextdir = (struct ext2_dir_entry *) 173 ((char *) dirent + 12); 174 dirent->rec_len = 12; 175 nextdir->rec_len = new_len; 176 nextdir->inode = 0; 177 nextdir->name_len = 0; 178 status = 1; 179 } 180 } 181 } 182 return status; 183} 184 185/* 186 * Make sure the second entry in the directory is '..', and that the 187 * directory entry is sane. We do not check the inode number of '..' 188 * here; this gets done in pass 3. 189 */ 190static int check_dotdot(ext2_filsys fs, 191 struct ext2_dir_entry *dirent, 192 struct dir_info *dir, struct problem_context *pctx) 193{ 194 int problem = 0; 195 196 if (!dirent->inode) 197 problem = PR_2_MISSING_DOT_DOT; 198 else if ((dirent->name_len != 2) || 199 (dirent->name[0] != '.') || 200 (dirent->name[1] != '.')) 201 problem = PR_2_2ND_NOT_DOT_DOT; 202 else if (dirent->name[2] != '\0') 203 problem = PR_2_DOT_DOT_NULL_TERM; 204 205 if (problem) { 206 if (fix_problem(fs, problem, pctx)) { 207 if (dirent->rec_len < 12) 208 dirent->rec_len = 12; 209 /* 210 * Note: we don't have the parent inode just 211 * yet, so we will fill it in with the root 212 * inode. This will get fixed in pass 3. 213 */ 214 dirent->inode = EXT2_ROOT_INO; 215 dirent->name_len = 2; 216 dirent->name[0] = '.'; 217 dirent->name[1] = '.'; 218 dirent->name[2] = '\0'; 219 return 1; 220 } 221 return 0; 222 } 223 dir->dotdot = dirent->inode; 224 return 0; 225} 226 227/* 228 * Check to make sure a directory entry doesn't contain any illegal 229 * characters. 230 */ 231static int check_name(ext2_filsys fs, 232 struct ext2_dir_entry *dirent, 233 ino_t dir_ino, struct problem_context *pctx) 234{ 235 int i; 236 int fixup = -1; 237 int ret = 0; 238 239 for ( i = 0; i < dirent->name_len; i++) { 240 if (dirent->name[i] == '/' || dirent->name[i] == '\0') { 241 if (fixup < 0) { 242 fixup = fix_problem(fs, PR_2_BAD_NAME, pctx); 243 } 244 if (fixup) { 245 dirent->name[i] = '.'; 246 ret = 1; 247 } 248 } 249 } 250 return ret; 251} 252 253static int check_dir_block(ext2_filsys fs, 254 struct ext2_db_entry *db, 255 void *private) 256{ 257 struct dir_info *subdir, *dir; 258 struct ext2_dir_entry *dirent; 259 int offset = 0; 260 int dir_modified = 0; 261 errcode_t retval; 262 int dot_state; 263 blk_t block_nr = db->blk; 264 ino_t ino = db->ino; 265 __u16 links; 266 struct check_dir_struct *cd = private; 267 char *buf = cd->buf; 268 269 /* 270 * Make sure the inode is still in use (could have been 271 * deleted in the duplicate/bad blocks pass. 272 */ 273 if (!(ext2fs_test_inode_bitmap(inode_used_map, ino))) 274 return 0; 275 276 cd->pctx.ino = ino; 277 cd->pctx.blk = block_nr; 278 cd->pctx.blkcount = db->blockcnt; 279 cd->pctx.ino2 = 0; 280 cd->pctx.dirent = 0; 281 cd->pctx.num = 0; 282 283 if (db->blk == 0) { 284 if (allocate_dir_block(fs, db, buf, &cd->pctx)) 285 return 0; 286 block_nr = db->blk; 287 } 288 289 if (db->blockcnt) 290 dot_state = 2; 291 else 292 dot_state = 0; 293 294#if 0 295 printf("In process_dir_block block %lu, #%d, inode %lu\n", block_nr, 296 db->blockcnt, ino); 297#endif 298 299 retval = ext2fs_read_dir_block(fs, block_nr, buf); 300 if (retval) { 301 com_err(program_name, retval, 302 "while reading directory block %d", block_nr); 303 } 304 305 do { 306 dot_state++; 307 dirent = (struct ext2_dir_entry *) (buf + offset); 308 cd->pctx.dirent = dirent; 309 cd->pctx.num = offset; 310 if (((offset + dirent->rec_len) > fs->blocksize) || 311 (dirent->rec_len < 8) || 312 ((dirent->rec_len % 4) != 0) || 313 ((dirent->name_len+8) > dirent->rec_len)) { 314 if (fix_problem(fs, PR_2_DIR_CORRUPTED, &cd->pctx)) { 315 dirent->rec_len = fs->blocksize - offset; 316 dirent->name_len = 0; 317 dirent->inode = 0; 318 dir_modified++; 319 } else 320 return DIRENT_ABORT; 321 } 322 323 if (dirent->name_len > EXT2_NAME_LEN) { 324 if (fix_problem(fs, PR_2_FILENAME_LONG, &cd->pctx)) { 325 dirent->name_len = EXT2_NAME_LEN; 326 dir_modified++; 327 } 328 } 329 330 if (dot_state == 1) { 331 if (check_dot(fs, dirent, ino, &cd->pctx)) 332 dir_modified++; 333 } else if (dot_state == 2) { 334 dir = get_dir_info(ino); 335 if (!dir) { 336 printf("Internal error: couldn't find dir_info for %lu\n", 337 ino); 338 fatal_error(0); 339 } 340 if (check_dotdot(fs, dirent, dir, &cd->pctx)) 341 dir_modified++; 342 } else if (dirent->inode == ino) { 343 if (fix_problem(fs, PR_2_LINK_DOT, &cd->pctx)) { 344 dirent->inode = 0; 345 dir_modified++; 346 goto next; 347 } 348 } 349 if (!dirent->inode) 350 goto next; 351 352 if (check_name(fs, dirent, ino, &cd->pctx)) 353 dir_modified++; 354 355 /* 356 * Make sure the inode listed is a legal one. 357 */ 358 if (((dirent->inode != EXT2_ROOT_INO) && 359 (dirent->inode < EXT2_FIRST_INODE(fs->super))) || 360 (dirent->inode > fs->super->s_inodes_count)) { 361 if (fix_problem(fs, PR_2_BAD_INO, &cd->pctx)) { 362 dirent->inode = 0; 363 dir_modified++; 364 goto next; 365 } 366 } 367 368 /* 369 * If the inode is unused, offer to clear it. 370 */ 371 if (!(ext2fs_test_inode_bitmap(inode_used_map, 372 dirent->inode))) { 373 if (fix_problem(fs, PR_2_UNUSED_INODE, &cd->pctx)) { 374 dirent->inode = 0; 375 dir_modified++; 376 goto next; 377 } 378 } 379 380 /* 381 * If the inode is in a bad block, offer to clear it. 382 */ 383 if (inode_bb_map && 384 (ext2fs_test_inode_bitmap(inode_bb_map, 385 dirent->inode))) { 386 if (fix_problem(fs, PR_2_BB_INODE, &cd->pctx)) { 387 dirent->inode = 0; 388 dir_modified++; 389 goto next; 390 } 391 } 392 393 /* 394 * If the inode was marked as having bad fields in 395 * pass1, process it and offer to fix/clear it. 396 * (We wait until now so that we can display the 397 * pathname to the user.) 398 */ 399 if (inode_bad_map && 400 ext2fs_test_inode_bitmap(inode_bad_map, 401 dirent->inode)) { 402 if (process_bad_inode(fs, ino, dirent->inode)) { 403 dirent->inode = 0; 404 dir_modified++; 405 goto next; 406 } 407 } 408 409 /* 410 * Don't allow links to the root directory. We check 411 * this specially to make sure we catch this error 412 * case even if the root directory hasn't been created 413 * yet. 414 */ 415 if ((dot_state > 2) && (dirent->inode == EXT2_ROOT_INO)) { 416 if (fix_problem(fs, PR_2_LINK_ROOT, &cd->pctx)) { 417 dirent->inode = 0; 418 dir_modified++; 419 goto next; 420 } 421 } 422 423 /* 424 * If this is a directory, then mark its parent in its 425 * dir_info structure. If the parent field is already 426 * filled in, then this directory has more than one 427 * hard link. We assume the first link is correct, 428 * and ask the user if he/she wants to clear this one. 429 */ 430 if ((dot_state > 2) && 431 (ext2fs_test_inode_bitmap(inode_dir_map, 432 dirent->inode))) { 433 subdir = get_dir_info(dirent->inode); 434 if (!subdir) { 435 printf("INTERNAL ERROR: missing dir %u\n", 436 dirent->inode); 437 fatal_error(0); 438 } 439 if (subdir->parent) { 440 cd->pctx.ino2 = subdir->parent; 441 if (fix_problem(fs, PR_2_LINK_DIR, 442 &cd->pctx)) { 443 dirent->inode = 0; 444 dir_modified++; 445 goto next; 446 } 447 cd->pctx.ino2 = 0; 448 } else 449 subdir->parent = ino; 450 } 451 452 ext2fs_icount_increment(inode_count, dirent->inode, &links); 453 if (links > 1) 454 fs_links_count++; 455 fs_total_count++; 456 next: 457 offset += dirent->rec_len; 458 } while (offset < fs->blocksize); 459#if 0 460 printf("\n"); 461#endif 462 if (offset != fs->blocksize) { 463 printf("Final rec_len is %d, should be %d\n", 464 dirent->rec_len, 465 dirent->rec_len - fs->blocksize + offset); 466 } 467 if (dir_modified) { 468 retval = ext2fs_write_dir_block(fs, block_nr, buf); 469 if (retval) { 470 com_err(program_name, retval, 471 "while writing directory block %d", block_nr); 472 } 473 ext2fs_mark_changed(fs); 474 } 475 return 0; 476} 477 478/* 479 * This function is called to deallocate a block, and is an interator 480 * functioned called by deallocate inode via ext2fs_iterate_block(). 481 */ 482static int deallocate_inode_block(ext2_filsys fs, 483 blk_t *block_nr, 484 int blockcnt, 485 void *private) 486{ 487 if (!*block_nr) 488 return 0; 489 ext2fs_unmark_block_bitmap(block_found_map, *block_nr); 490 ext2fs_unmark_block_bitmap(fs->block_map, *block_nr); 491 return 0; 492} 493 494/* 495 * This fuction deallocates an inode 496 */ 497static void deallocate_inode(ext2_filsys fs, ino_t ino, 498 char* block_buf) 499{ 500 errcode_t retval; 501 struct ext2_inode inode; 502 503 ext2fs_icount_store(inode_link_info, ino, 0); 504 e2fsck_read_inode(fs, ino, &inode, "deallocate_inode"); 505 inode.i_links_count = 0; 506 inode.i_dtime = time(0); 507 e2fsck_write_inode(fs, ino, &inode, "deallocate_inode"); 508 509 /* 510 * Fix up the bitmaps... 511 */ 512 read_bitmaps(fs); 513 ext2fs_unmark_inode_bitmap(inode_used_map, ino); 514 ext2fs_unmark_inode_bitmap(inode_dir_map, ino); 515 if (inode_bad_map) 516 ext2fs_unmark_inode_bitmap(inode_bad_map, ino); 517 ext2fs_unmark_inode_bitmap(fs->inode_map, ino); 518 ext2fs_mark_ib_dirty(fs); 519 520 if (!ext2fs_inode_has_valid_blocks(&inode)) 521 return; 522 523 ext2fs_mark_bb_dirty(fs); 524 retval = ext2fs_block_iterate(fs, ino, 0, block_buf, 525 deallocate_inode_block, 0); 526 if (retval) 527 com_err("deallocate_inode", retval, 528 "while calling ext2fs_block_iterate for inode %d", 529 ino); 530} 531 532static int process_bad_inode(ext2_filsys fs, ino_t dir, ino_t ino) 533{ 534 struct ext2_inode inode; 535 int inode_modified = 0; 536 unsigned char *frag, *fsize; 537 struct problem_context pctx; 538 539 e2fsck_read_inode(fs, ino, &inode, "process_bad_inode"); 540 541 clear_problem_context(&pctx); 542 pctx.ino = ino; 543 pctx.dir = dir; 544 pctx.inode = &inode; 545 546 if (!LINUX_S_ISDIR(inode.i_mode) && !LINUX_S_ISREG(inode.i_mode) && 547 !LINUX_S_ISCHR(inode.i_mode) && !LINUX_S_ISBLK(inode.i_mode) && 548 !LINUX_S_ISLNK(inode.i_mode) && !LINUX_S_ISFIFO(inode.i_mode) && 549 !(LINUX_S_ISSOCK(inode.i_mode))) { 550 if (fix_problem(fs, PR_2_BAD_MODE, &pctx)) { 551 deallocate_inode(fs, ino, 0); 552 return 1; 553 } 554 } 555 if (inode.i_faddr && 556 fix_problem(fs, PR_2_FADDR_ZERO, &pctx)) { 557 inode.i_faddr = 0; 558 inode_modified++; 559 } 560 561 switch (fs->super->s_creator_os) { 562 case EXT2_OS_LINUX: 563 frag = &inode.osd2.linux2.l_i_frag; 564 fsize = &inode.osd2.linux2.l_i_fsize; 565 break; 566 case EXT2_OS_HURD: 567 frag = &inode.osd2.hurd2.h_i_frag; 568 fsize = &inode.osd2.hurd2.h_i_fsize; 569 break; 570 case EXT2_OS_MASIX: 571 frag = &inode.osd2.masix2.m_i_frag; 572 fsize = &inode.osd2.masix2.m_i_fsize; 573 break; 574 default: 575 frag = fsize = 0; 576 } 577 if (frag && *frag) { 578 pctx.num = *frag; 579 if (fix_problem(fs, PR_2_FRAG_ZERO, &pctx)) { 580 *frag = 0; 581 inode_modified++; 582 } 583 pctx.num = 0; 584 } 585 if (fsize && *fsize) { 586 pctx.num = *fsize; 587 if (fix_problem(fs, PR_2_FSIZE_ZERO, &pctx)) { 588 *fsize = 0; 589 inode_modified++; 590 } 591 pctx.num = 0; 592 } 593 594 if (inode.i_file_acl && 595 fix_problem(fs, PR_2_FILE_ACL_ZERO, &pctx)) { 596 inode.i_file_acl = 0; 597 inode_modified++; 598 } 599 if (inode.i_dir_acl && 600 fix_problem(fs, PR_2_DIR_ACL_ZERO, &pctx)) { 601 inode.i_dir_acl = 0; 602 inode_modified++; 603 } 604 if (inode_modified) 605 e2fsck_write_inode(fs, ino, &inode, "process_bad_inode"); 606 return 0; 607} 608 609 610/* 611 * allocate_dir_block --- this function allocates a new directory 612 * block for a particular inode; this is done if a directory has 613 * a "hole" in it, or if a directory has a illegal block number 614 * that was zeroed out and now needs to be replaced. 615 */ 616static int allocate_dir_block(ext2_filsys fs, 617 struct ext2_db_entry *db, 618 char *buf, struct problem_context *pctx) 619{ 620 blk_t blk; 621 char *block; 622 struct ext2_inode inode; 623 errcode_t retval; 624 625 if (fix_problem(fs, PR_2_DIRECTORY_HOLE, pctx) == 0) 626 return 1; 627 628 /* 629 * Read the inode and block bitmaps in; we'll be messing with 630 * them. 631 */ 632 read_bitmaps(fs); 633 634 /* 635 * First, find a free block 636 */ 637 retval = ext2fs_new_block(fs, 0, block_found_map, &blk); 638 if (retval) { 639 com_err("allocate_dir_block", retval, 640 "while trying to fill a hole in a directory inode"); 641 return 1; 642 } 643 ext2fs_mark_block_bitmap(block_found_map, blk); 644 ext2fs_mark_block_bitmap(fs->block_map, blk); 645 ext2fs_mark_bb_dirty(fs); 646 647 /* 648 * Now let's create the actual data block for the inode 649 */ 650 if (db->blockcnt) 651 retval = ext2fs_new_dir_block(fs, 0, 0, &block); 652 else 653 retval = ext2fs_new_dir_block(fs, db->ino, EXT2_ROOT_INO, 654 &block); 655 656 if (retval) { 657 com_err("allocate_dir_block", retval, 658 "while creating new directory block"); 659 return 1; 660 } 661 662 retval = ext2fs_write_dir_block(fs, blk, block); 663 free(block); 664 if (retval) { 665 com_err("allocate_dir_block", retval, 666 "while writing an empty directory block"); 667 return 1; 668 } 669 670 /* 671 * Update the inode block count 672 */ 673 e2fsck_read_inode(fs, db->ino, &inode, "allocate_dir_block"); 674 inode.i_blocks += fs->blocksize / 512; 675 if (inode.i_size < (db->blockcnt+1) * fs->blocksize) 676 inode.i_size = (db->blockcnt+1) * fs->blocksize; 677 e2fsck_write_inode(fs, db->ino, &inode, "allocate_dir_block"); 678 679 /* 680 * Finally, update the block pointers for the inode 681 */ 682 db->blk = blk; 683 retval = ext2fs_block_iterate(fs, db->ino, BLOCK_FLAG_HOLE, 684 0, update_dir_block, db); 685 if (retval) { 686 com_err("allocate_dir_block", retval, 687 "while calling ext2fs_block_iterate"); 688 return 1; 689 } 690 691 return 0; 692} 693 694/* 695 * This is a helper function for allocate_dir_block(). 696 */ 697static int update_dir_block(ext2_filsys fs, 698 blk_t *block_nr, 699 int blockcnt, 700 void *private) 701{ 702 struct ext2_db_entry *db = private; 703 704 if (db->blockcnt == blockcnt) { 705 *block_nr = db->blk; 706 return BLOCK_CHANGED; 707 } 708 return 0; 709} 710 711