pass3.c revision c555aebde40afdc0d15d674f2c81c0e05cfded3f
1/* 2 * pass3.c -- pass #3 of e2fsck: Check for directory connectivity 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 #3 assures that all directories are connected to the 12 * filesystem tree, using the following algorithm: 13 * 14 * First, the root directory is checked to make sure it exists; if 15 * not, e2fsck will offer to create a new one. It is then marked as 16 * "done". 17 * 18 * Then, pass3 interates over all directory inodes; for each directory 19 * it attempts to trace up the filesystem tree, using dirinfo.parent 20 * until it reaches a directory which has been marked "done". If it 21 * can not do so, then the directory must be disconnected, and e2fsck 22 * will offer to reconnect it to /lost+found. While it is chasing 23 * parent pointers up the filesystem tree, if pass3 sees a directory 24 * twice, then it has detected a filesystem loop, and it will again 25 * offer to reconnect the directory to /lost+found in to break the 26 * filesystem loop. 27 * 28 * Pass 3 also contains the subroutine, reconnect_file() to reconnect 29 * inodes to /lost+found; this subroutine is also used by pass 4. 30 * reconnect_file() calls get_lost_and_found(), which is responsible 31 * for creating /lost+found if it does not exist. 32 * 33 * Pass 3 frees the following data structures: 34 * - The dirinfo directory information cache. 35 */ 36 37#ifdef HAVE_ERRNO_H 38#include <errno.h> 39#endif 40 41#include "e2fsck.h" 42#include "problem.h" 43 44static void check_root(e2fsck_t ctx); 45static void check_directory(e2fsck_t ctx, struct dir_info *dir, 46 struct problem_context *pctx); 47static ino_t get_lost_and_found(e2fsck_t ctx); 48static void fix_dotdot(e2fsck_t ctx, struct dir_info *dir, ino_t parent); 49static errcode_t adjust_inode_count(e2fsck_t ctx, ino_t ino, int adj); 50static errcode_t expand_directory(e2fsck_t ctx, ino_t dir); 51 52static ino_t lost_and_found = 0; 53static int bad_lost_and_found = 0; 54 55static ext2fs_inode_bitmap inode_loop_detect; 56static ext2fs_inode_bitmap inode_done_map; 57 58void pass3(e2fsck_t ctx) 59{ 60 ext2_filsys fs = ctx->fs; 61 int i; 62#ifdef RESOURCE_TRACK 63 struct resource_track rtrack; 64#endif 65 struct problem_context pctx; 66 struct dir_info *dir; 67 68#ifdef RESOURCE_TRACK 69 init_resource_track(&rtrack); 70#endif 71 72 clear_problem_context(&pctx); 73 74#ifdef MTRACE 75 mtrace_print("Pass 3"); 76#endif 77 78 if (!(ctx->options & E2F_OPT_PREEN)) 79 fix_problem(ctx, PR_3_PASS_HEADER, &pctx); 80 81 /* 82 * Allocate some bitmaps to do loop detection. 83 */ 84 pctx.errcode = ext2fs_allocate_inode_bitmap(fs, 85 "inode loop detection bitmap", &inode_loop_detect); 86 if (pctx.errcode) { 87 pctx.num = 1; 88 fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx); 89 fatal_error(0); 90 } 91 pctx.errcode = ext2fs_allocate_inode_bitmap(fs, "inode done bitmap", 92 &inode_done_map); 93 if (pctx.errcode) { 94 pctx.num = 2; 95 fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx); 96 fatal_error(0); 97 } 98#ifdef RESOURCE_TRACK 99 if (ctx->options & E2F_OPT_TIME) 100 print_resource_track("Peak memory", &ctx->global_rtrack); 101#endif 102 103 check_root(ctx); 104 ext2fs_mark_inode_bitmap(inode_done_map, EXT2_ROOT_INO); 105 106 for (i=0; (dir = dir_info_iter(&i)) != 0;) { 107 if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, dir->ino)) 108 check_directory(ctx, dir, &pctx); 109 } 110 111 112 free_dir_info(fs); 113 ext2fs_free_inode_bitmap(inode_loop_detect); 114 ext2fs_free_inode_bitmap(inode_done_map); 115#ifdef RESOURCE_TRACK 116 if (ctx->options & E2F_OPT_TIME2) 117 print_resource_track("Pass 3", &rtrack); 118#endif 119} 120 121/* 122 * This makes sure the root inode is present; if not, we ask if the 123 * user wants us to create it. Not creating it is a fatal error. 124 */ 125static void check_root(e2fsck_t ctx) 126{ 127 ext2_filsys fs = ctx->fs; 128 blk_t blk; 129 struct ext2_inode inode; 130 char * block; 131 struct problem_context pctx; 132 133 clear_problem_context(&pctx); 134 135 if (ext2fs_test_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO)) { 136 /* 137 * If the root inode is a directory, die here. The 138 * user must have answered 'no' in pass1 when we 139 * offered to clear it. 140 */ 141 if (!(ext2fs_test_inode_bitmap(ctx->inode_dir_map, 142 EXT2_ROOT_INO))) 143 fatal_error("Root inode not directory"); 144 return; 145 } 146 147 if (!fix_problem(ctx, PR_3_NO_ROOT_INODE, &pctx)) 148 fatal_error("Cannot proceed without a root inode."); 149 150 read_bitmaps(ctx); 151 152 /* 153 * First, find a free block 154 */ 155 pctx.errcode = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk); 156 if (pctx.errcode) { 157 pctx.str = "ext2fs_new_block"; 158 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx); 159 fatal_error(0); 160 } 161 ext2fs_mark_block_bitmap(ctx->block_found_map, blk); 162 ext2fs_mark_block_bitmap(fs->block_map, blk); 163 ext2fs_mark_bb_dirty(fs); 164 165 /* 166 * Now let's create the actual data block for the inode 167 */ 168 pctx.errcode = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO, 169 &block); 170 if (pctx.errcode) { 171 pctx.str = "ext2fs_new_dir_block"; 172 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx); 173 fatal_error(0); 174 } 175 176 pctx.errcode = ext2fs_write_dir_block(fs, blk, block); 177 if (pctx.errcode) { 178 pctx.str = "ext2fs_write_dir_block"; 179 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx); 180 fatal_error(0); 181 } 182 free(block); 183 184 /* 185 * Set up the inode structure 186 */ 187 memset(&inode, 0, sizeof(inode)); 188 inode.i_mode = 040755; 189 inode.i_size = fs->blocksize; 190 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0); 191 inode.i_links_count = 2; 192 inode.i_blocks = fs->blocksize / 512; 193 inode.i_block[0] = blk; 194 195 /* 196 * Write out the inode. 197 */ 198 pctx.errcode = ext2fs_write_inode(fs, EXT2_ROOT_INO, &inode); 199 if (pctx.errcode) { 200 pctx.str = "ext2fs_write_inode"; 201 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx); 202 fatal_error(0); 203 } 204 205 /* 206 * Miscellaneous bookkeeping... 207 */ 208 add_dir_info(fs, EXT2_ROOT_INO, EXT2_ROOT_INO); 209 ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2); 210 ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2); 211 212 ext2fs_mark_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO); 213 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, EXT2_ROOT_INO); 214 ext2fs_mark_inode_bitmap(fs->inode_map, EXT2_ROOT_INO); 215 ext2fs_mark_ib_dirty(fs); 216} 217 218/* 219 * This subroutine is responsible for making sure that a particular 220 * directory is connected to the root; if it isn't we trace it up as 221 * far as we can go, and then offer to connect the resulting parent to 222 * the lost+found. We have to do loop detection; if we ever discover 223 * a loop, we treat that as a disconnected directory and offer to 224 * reparent it to lost+found. 225 */ 226static void check_directory(e2fsck_t ctx, struct dir_info *dir, 227 struct problem_context *pctx) 228{ 229 ext2_filsys fs = ctx->fs; 230 struct dir_info *p = dir; 231 232 ext2fs_clear_inode_bitmap(inode_loop_detect); 233 while (p) { 234 /* 235 * If we find a parent which we've already checked, 236 * then stop; we know it's either already connected to 237 * the directory tree, or it isn't but the user has 238 * already told us he doesn't want us to reconnect the 239 * disconnected subtree. 240 */ 241 if (ext2fs_test_inode_bitmap(inode_done_map, p->ino)) 242 goto check_dot_dot; 243 /* 244 * Mark this inode as being "done"; by the time we 245 * return from this function, the inode we either be 246 * verified as being connected to the directory tree, 247 * or we will have offered to reconnect this to 248 * lost+found. 249 */ 250 ext2fs_mark_inode_bitmap(inode_done_map, p->ino); 251 /* 252 * If this directory doesn't have a parent, or we've 253 * seen the parent once already, then offer to 254 * reparent it to lost+found 255 */ 256 if (!p->parent || 257 (ext2fs_test_inode_bitmap(inode_loop_detect, 258 p->parent))) 259 break; 260 ext2fs_mark_inode_bitmap(inode_loop_detect, 261 p->parent); 262 p = get_dir_info(p->parent); 263 } 264 /* 265 * If we've reached here, we've hit a detached directory 266 * inode; offer to reconnect it to lost+found. 267 */ 268 pctx->ino = p->ino; 269 if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) { 270 if (reconnect_file(ctx, p->ino)) 271 ext2fs_unmark_valid(fs); 272 else { 273 p->parent = lost_and_found; 274 fix_dotdot(ctx, p, lost_and_found); 275 } 276 } 277 278 /* 279 * Make sure that .. and the parent directory are the same; 280 * offer to fix it if not. 281 */ 282check_dot_dot: 283 if (dir->parent != dir->dotdot) { 284 pctx->ino = dir->ino; 285 pctx->ino2 = dir->dotdot; 286 pctx->dir = dir->parent; 287 if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx)) 288 fix_dotdot(ctx, dir, dir->parent); 289 } 290} 291 292/* 293 * This routine gets the lost_and_found inode, making it a directory 294 * if necessary 295 */ 296ino_t get_lost_and_found(e2fsck_t ctx) 297{ 298 ext2_filsys fs = ctx->fs; 299 ino_t ino; 300 blk_t blk; 301 errcode_t retval; 302 struct ext2_inode inode; 303 char * block; 304 const char name[] = "lost+found"; 305 struct problem_context pctx; 306 307 clear_problem_context(&pctx); 308 309 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name, 310 sizeof(name)-1, 0, &ino); 311 if (!retval) 312 return ino; 313 if (retval != EXT2_FILE_NOT_FOUND) { 314 pctx.errcode = retval; 315 fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx); 316 } 317 if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0)) 318 return 0; 319 320 /* 321 * Read the inode and block bitmaps in; we'll be messing with 322 * them. 323 */ 324 read_bitmaps(ctx); 325 326 /* 327 * First, find a free block 328 */ 329 retval = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk); 330 if (retval) { 331 pctx.errcode = retval; 332 fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx); 333 return 0; 334 } 335 ext2fs_mark_block_bitmap(ctx->block_found_map, blk); 336 ext2fs_mark_block_bitmap(fs->block_map, blk); 337 ext2fs_mark_bb_dirty(fs); 338 339 /* 340 * Next find a free inode. 341 */ 342 retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040755, 343 ctx->inode_used_map, &ino); 344 if (retval) { 345 pctx.errcode = retval; 346 fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx); 347 return 0; 348 } 349 ext2fs_mark_inode_bitmap(ctx->inode_used_map, ino); 350 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, ino); 351 ext2fs_mark_inode_bitmap(fs->inode_map, ino); 352 ext2fs_mark_ib_dirty(fs); 353 354 /* 355 * Now let's create the actual data block for the inode 356 */ 357 retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block); 358 if (retval) { 359 pctx.errcode = retval; 360 fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx); 361 return 0; 362 } 363 364 retval = ext2fs_write_dir_block(fs, blk, block); 365 free(block); 366 if (retval) { 367 pctx.errcode = retval; 368 fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx); 369 return 0; 370 } 371 372 /* 373 * Set up the inode structure 374 */ 375 memset(&inode, 0, sizeof(inode)); 376 inode.i_mode = 040755; 377 inode.i_size = fs->blocksize; 378 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0); 379 inode.i_links_count = 2; 380 inode.i_blocks = fs->blocksize / 512; 381 inode.i_block[0] = blk; 382 383 /* 384 * Next, write out the inode. 385 */ 386 pctx.errcode = ext2fs_write_inode(fs, ino, &inode); 387 if (pctx.errcode) { 388 pctx.str = "ext2fs_write_inode"; 389 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx); 390 return 0; 391 } 392 /* 393 * Finally, create the directory link 394 */ 395 pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, 0); 396 if (pctx.errcode) { 397 pctx.str = "ext2fs_link"; 398 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx); 399 return 0; 400 } 401 402 /* 403 * Miscellaneous bookkeeping that needs to be kept straight. 404 */ 405 add_dir_info(fs, ino, EXT2_ROOT_INO); 406 adjust_inode_count(ctx, EXT2_ROOT_INO, +1); 407 ext2fs_icount_store(ctx->inode_count, ino, 2); 408 ext2fs_icount_store(ctx->inode_link_info, ino, 2); 409#if 0 410 printf("/lost+found created; inode #%lu\n", ino); 411#endif 412 return ino; 413} 414 415/* 416 * This routine will connect a file to lost+found 417 */ 418int reconnect_file(e2fsck_t ctx, ino_t inode) 419{ 420 ext2_filsys fs = ctx->fs; 421 errcode_t retval; 422 char name[80]; 423 struct problem_context pctx; 424 425 clear_problem_context(&pctx); 426 pctx.ino = inode; 427 428 if (!bad_lost_and_found && !lost_and_found) { 429 lost_and_found = get_lost_and_found(ctx); 430 if (!lost_and_found) 431 bad_lost_and_found++; 432 } 433 if (bad_lost_and_found) { 434 fix_problem(ctx, PR_3_NO_LPF, &pctx); 435 return 1; 436 } 437 438 sprintf(name, "#%lu", inode); 439 retval = ext2fs_link(fs, lost_and_found, name, inode, 0); 440 if (retval == EXT2_ET_DIR_NO_SPACE) { 441 if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx)) 442 return 1; 443 retval = expand_directory(ctx, lost_and_found); 444 if (retval) { 445 pctx.errcode = retval; 446 fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx); 447 return 1; 448 } 449 retval = ext2fs_link(fs, lost_and_found, name, inode, 0); 450 } 451 if (retval) { 452 pctx.errcode = retval; 453 fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx); 454 return 1; 455 } 456 adjust_inode_count(ctx, inode, +1); 457 458 return 0; 459} 460 461/* 462 * Utility routine to adjust the inode counts on an inode. 463 */ 464static errcode_t adjust_inode_count(e2fsck_t ctx, ino_t ino, int adj) 465{ 466 ext2_filsys fs = ctx->fs; 467 errcode_t retval; 468 struct ext2_inode inode; 469 470 if (!ino) 471 return 0; 472 473 retval = ext2fs_read_inode(fs, ino, &inode); 474 if (retval) 475 return retval; 476 477#if 0 478 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj, 479 inode.i_links_count); 480#endif 481 482 inode.i_links_count += adj; 483 if (adj == 1) { 484 ext2fs_icount_increment(ctx->inode_count, ino, 0); 485 ext2fs_icount_increment(ctx->inode_link_info, ino, 0); 486 } else { 487 ext2fs_icount_decrement(ctx->inode_count, ino, 0); 488 ext2fs_icount_decrement(ctx->inode_link_info, ino, 0); 489 } 490 491 492 retval = ext2fs_write_inode(fs, ino, &inode); 493 if (retval) 494 return retval; 495 496 return 0; 497} 498 499/* 500 * Fix parent --- this routine fixes up the parent of a directory. 501 */ 502struct fix_dotdot_struct { 503 ext2_filsys fs; 504 ino_t parent; 505 int done; 506 e2fsck_t ctx; 507}; 508 509static int fix_dotdot_proc(struct ext2_dir_entry *dirent, 510 int offset, 511 int blocksize, 512 char *buf, 513 void *private) 514{ 515 struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) private; 516 errcode_t retval; 517 struct problem_context pctx; 518 519 if (dirent->name_len != 2) 520 return 0; 521 if (strncmp(dirent->name, "..", 2)) 522 return 0; 523 524 clear_problem_context(&pctx); 525 526 retval = adjust_inode_count(fp->ctx, dirent->inode, -1); 527 if (retval) { 528 pctx.errcode = retval; 529 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx); 530 } 531 retval = adjust_inode_count(fp->ctx, fp->parent, 1); 532 if (retval) { 533 pctx.errcode = retval; 534 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx); 535 } 536 dirent->inode = fp->parent; 537 538 fp->done++; 539 return DIRENT_ABORT | DIRENT_CHANGED; 540} 541 542static void fix_dotdot(e2fsck_t ctx, struct dir_info *dir, ino_t parent) 543{ 544 ext2_filsys fs = ctx->fs; 545 errcode_t retval; 546 struct fix_dotdot_struct fp; 547 struct problem_context pctx; 548 549 fp.fs = fs; 550 fp.parent = parent; 551 fp.done = 0; 552 fp.ctx = ctx; 553 554#if 0 555 printf("Fixing '..' of inode %lu to be %lu...\n", dir->ino, parent); 556#endif 557 558 retval = ext2fs_dir_iterate(fs, dir->ino, DIRENT_FLAG_INCLUDE_EMPTY, 559 0, fix_dotdot_proc, &fp); 560 if (retval || !fp.done) { 561 clear_problem_context(&pctx); 562 pctx.ino = dir->ino; 563 pctx.errcode = retval; 564 fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR : 565 PR_3_FIX_PARENT_NOFIND, &pctx); 566 ext2fs_unmark_valid(fs); 567 } 568 dir->dotdot = parent; 569 570 return; 571} 572 573/* 574 * These routines are responsible for expanding a /lost+found if it is 575 * too small. 576 */ 577 578struct expand_dir_struct { 579 int done; 580 errcode_t err; 581 e2fsck_t ctx; 582}; 583 584static int expand_dir_proc(ext2_filsys fs, 585 blk_t *blocknr, 586 int blockcnt, 587 void *private) 588{ 589 struct expand_dir_struct *es = (struct expand_dir_struct *) private; 590 blk_t new_blk; 591 static blk_t last_blk = 0; 592 char *block; 593 errcode_t retval; 594 e2fsck_t ctx; 595 596 ctx = es->ctx; 597 598 if (*blocknr) { 599 last_blk = *blocknr; 600 return 0; 601 } 602 retval = ext2fs_new_block(fs, last_blk, ctx->block_found_map, 603 &new_blk); 604 if (retval) { 605 es->err = retval; 606 return BLOCK_ABORT; 607 } 608 if (blockcnt > 0) { 609 retval = ext2fs_new_dir_block(fs, 0, 0, &block); 610 if (retval) { 611 es->err = retval; 612 return BLOCK_ABORT; 613 } 614 es->done = 1; 615 } else { 616 block = malloc(fs->blocksize); 617 if (!block) { 618 es->err = ENOMEM; 619 return BLOCK_ABORT; 620 } 621 memset(block, 0, fs->blocksize); 622 } 623 retval = ext2fs_write_dir_block(fs, new_blk, block); 624 if (retval) { 625 es->err = retval; 626 return BLOCK_ABORT; 627 } 628 free(block); 629 *blocknr = new_blk; 630 ext2fs_mark_block_bitmap(ctx->block_found_map, new_blk); 631 ext2fs_mark_block_bitmap(fs->block_map, new_blk); 632 ext2fs_mark_bb_dirty(fs); 633 if (es->done) 634 return (BLOCK_CHANGED | BLOCK_ABORT); 635 else 636 return BLOCK_CHANGED; 637} 638 639static errcode_t expand_directory(e2fsck_t ctx, ino_t dir) 640{ 641 ext2_filsys fs = ctx->fs; 642 errcode_t retval; 643 struct expand_dir_struct es; 644 struct ext2_inode inode; 645 646 if (!(fs->flags & EXT2_FLAG_RW)) 647 return EXT2_ET_RO_FILSYS; 648 649 retval = ext2fs_check_directory(fs, dir); 650 if (retval) 651 return retval; 652 653 es.done = 0; 654 es.err = 0; 655 es.ctx = ctx; 656 657 retval = ext2fs_block_iterate(fs, dir, BLOCK_FLAG_APPEND, 658 0, expand_dir_proc, &es); 659 660 if (es.err) 661 return es.err; 662 if (!es.done) 663 return EXT2_ET_EXPAND_DIR_ERR; 664 665 /* 666 * Update the size and block count fields in the inode. 667 */ 668 retval = ext2fs_read_inode(fs, dir, &inode); 669 if (retval) 670 return retval; 671 672 inode.i_size += fs->blocksize; 673 inode.i_blocks += fs->blocksize / 512; 674 675 e2fsck_write_inode(fs, dir, &inode, "expand_directory"); 676 677 return 0; 678} 679