2 * pass3.c -- pass #3 of e2fsck: Check for directory connectivity
4 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Public
11 * Pass #3 assures that all directories are connected to the
12 * filesystem tree, using the following algorithm:
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
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
28 * Pass 3 also contains the subroutine, e2fsck_reconnect_file() to
29 * reconnect inodes to /lost+found; this subroutine is also used by
30 * pass 4. e2fsck_reconnect_file() calls get_lost_and_found(), which
31 * is responsible for creating /lost+found if it does not exist.
33 * Pass 3 frees the following data structures:
34 * - The dirinfo directory information cache.
45 static void check_root(e2fsck_t ctx);
46 static int check_directory(e2fsck_t ctx, ext2_ino_t ino,
47 struct problem_context *pctx);
48 static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent);
50 static ext2fs_inode_bitmap inode_loop_detect = 0;
51 static ext2fs_inode_bitmap inode_done_map = 0;
53 void e2fsck_pass3(e2fsck_t ctx)
55 ext2_filsys fs = ctx->fs;
56 struct dir_info_iter *iter;
58 struct resource_track rtrack;
60 struct problem_context pctx;
62 unsigned long maxdirs, count;
64 init_resource_track(&rtrack, ctx->fs->io);
65 clear_problem_context(&pctx);
68 mtrace_print("Pass 3");
71 if (!(ctx->options & E2F_OPT_PREEN))
72 fix_problem(ctx, PR_3_PASS_HEADER, &pctx);
75 * Allocate some bitmaps to do loop detection.
77 pctx.errcode = e2fsck_allocate_inode_bitmap(fs, _("inode done bitmap"),
78 EXT2FS_BMAP64_AUTODIR,
79 "inode_done_map", &inode_done_map);
82 fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx);
83 ctx->flags |= E2F_FLAG_ABORT;
86 print_resource_track(ctx, _("Peak memory"), &ctx->global_rtrack, NULL);
89 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
92 ext2fs_mark_inode_bitmap2(inode_done_map, EXT2_ROOT_INO);
94 maxdirs = e2fsck_get_num_dirinfo(ctx);
98 if ((ctx->progress)(ctx, 3, 0, maxdirs))
101 iter = e2fsck_dir_info_iter_begin(ctx);
102 while ((dir = e2fsck_dir_info_iter(ctx, iter)) != 0) {
103 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
105 if (ctx->progress && (ctx->progress)(ctx, 3, count++, maxdirs))
107 if (ext2fs_test_inode_bitmap2(ctx->inode_dir_map, dir->ino))
108 if (check_directory(ctx, dir->ino, &pctx))
111 e2fsck_dir_info_iter_end(ctx, iter);
114 * Force the creation of /lost+found if not present
116 if ((ctx->flags & E2F_OPT_READONLY) == 0)
117 e2fsck_get_lost_and_found(ctx, 1);
120 * If there are any directories that need to be indexed or
121 * optimized, do it here.
123 e2fsck_rehash_directories(ctx);
126 e2fsck_free_dir_info(ctx);
127 if (inode_loop_detect) {
128 ext2fs_free_inode_bitmap(inode_loop_detect);
129 inode_loop_detect = 0;
131 if (inode_done_map) {
132 ext2fs_free_inode_bitmap(inode_done_map);
136 print_resource_track(ctx, _("Pass 3"), &rtrack, ctx->fs->io);
140 * This makes sure the root inode is present; if not, we ask if the
141 * user wants us to create it. Not creating it is a fatal error.
143 static void check_root(e2fsck_t ctx)
145 ext2_filsys fs = ctx->fs;
147 struct ext2_inode inode;
149 struct problem_context pctx;
151 clear_problem_context(&pctx);
153 if (ext2fs_test_inode_bitmap2(ctx->inode_used_map, EXT2_ROOT_INO)) {
155 * If the root inode is not a directory, die here. The
156 * user must have answered 'no' in pass1 when we
157 * offered to clear it.
159 if (!(ext2fs_test_inode_bitmap2(ctx->inode_dir_map,
161 fix_problem(ctx, PR_3_ROOT_NOT_DIR_ABORT, &pctx);
162 ctx->flags |= E2F_FLAG_ABORT;
167 if (!fix_problem(ctx, PR_3_NO_ROOT_INODE, &pctx)) {
168 fix_problem(ctx, PR_3_NO_ROOT_INODE_ABORT, &pctx);
169 ctx->flags |= E2F_FLAG_ABORT;
173 e2fsck_read_bitmaps(ctx);
176 * First, find a free block
178 pctx.errcode = ext2fs_new_block2(fs, 0, ctx->block_found_map, &blk);
180 pctx.str = "ext2fs_new_block";
181 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
182 ctx->flags |= E2F_FLAG_ABORT;
185 ext2fs_mark_block_bitmap2(ctx->block_found_map, blk);
186 ext2fs_mark_block_bitmap2(fs->block_map, blk);
187 ext2fs_mark_bb_dirty(fs);
190 * Now let's create the actual data block for the inode
192 pctx.errcode = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO,
195 pctx.str = "ext2fs_new_dir_block";
196 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
197 ctx->flags |= E2F_FLAG_ABORT;
201 pctx.errcode = ext2fs_write_dir_block4(fs, blk, block, 0,
204 pctx.str = "ext2fs_write_dir_block";
205 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
206 ctx->flags |= E2F_FLAG_ABORT;
209 ext2fs_free_mem(&block);
212 * Set up the inode structure
214 memset(&inode, 0, sizeof(inode));
215 inode.i_mode = 040755;
216 inode.i_size = fs->blocksize;
217 inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now;
218 inode.i_links_count = 2;
219 ext2fs_iblk_set(fs, &inode, 1);
220 inode.i_block[0] = blk;
223 * Write out the inode.
225 pctx.errcode = ext2fs_write_new_inode(fs, EXT2_ROOT_INO, &inode);
227 pctx.str = "ext2fs_write_inode";
228 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
229 ctx->flags |= E2F_FLAG_ABORT;
234 * Miscellaneous bookkeeping...
236 e2fsck_add_dir_info(ctx, EXT2_ROOT_INO, EXT2_ROOT_INO);
237 ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2);
238 ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2);
240 ext2fs_mark_inode_bitmap2(ctx->inode_used_map, EXT2_ROOT_INO);
241 ext2fs_mark_inode_bitmap2(ctx->inode_dir_map, EXT2_ROOT_INO);
242 ext2fs_mark_inode_bitmap2(fs->inode_map, EXT2_ROOT_INO);
243 ext2fs_mark_ib_dirty(fs);
247 * This subroutine is responsible for making sure that a particular
248 * directory is connected to the root; if it isn't we trace it up as
249 * far as we can go, and then offer to connect the resulting parent to
250 * the lost+found. We have to do loop detection; if we ever discover
251 * a loop, we treat that as a disconnected directory and offer to
252 * reparent it to lost+found.
254 * However, loop detection is expensive, because for very large
255 * filesystems, the inode_loop_detect bitmap is huge, and clearing it
256 * is non-trivial. Loops in filesystems are also a rare error case,
257 * and we shouldn't optimize for error cases. So we try two passes of
258 * the algorithm. The first time, we ignore loop detection and merely
259 * increment a counter; if the counter exceeds some extreme threshold,
260 * then we try again with the loop detection bitmap enabled.
262 static int check_directory(e2fsck_t ctx, ext2_ino_t dir,
263 struct problem_context *pctx)
265 ext2_filsys fs = ctx->fs;
266 ext2_ino_t ino = dir, parent;
267 int loop_pass = 0, parent_count = 0;
271 * Mark this inode as being "done"; by the time we
272 * return from this function, the inode we either be
273 * verified as being connected to the directory tree,
274 * or we will have offered to reconnect this to
277 * If it was marked done already, then we've reached a
278 * parent we've already checked.
280 if (ext2fs_mark_inode_bitmap2(inode_done_map, ino))
283 if (e2fsck_dir_info_get_parent(ctx, ino, &parent)) {
284 fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
289 * If this directory doesn't have a parent, or we've
290 * seen the parent once already, then offer to
291 * reparent it to lost+found
295 (ext2fs_test_inode_bitmap2(inode_loop_detect,
298 if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) {
299 if (e2fsck_reconnect_file(ctx, pctx->ino))
300 ext2fs_unmark_valid(fs);
302 fix_dotdot(ctx, pctx->ino,
303 ctx->lost_and_found);
304 parent = ctx->lost_and_found;
311 ext2fs_mark_inode_bitmap2(inode_loop_detect, ino);
312 } else if (parent_count++ > 2048) {
314 * If we've run into a path depth that's
315 * greater than 2048, try again with the inode
316 * loop bitmap turned on and start from the
320 if (inode_loop_detect)
321 ext2fs_clear_inode_bitmap(inode_loop_detect);
323 pctx->errcode = e2fsck_allocate_inode_bitmap(fs, _("inode loop detection bitmap"), EXT2FS_BMAP64_AUTODIR, "inode_loop_detect", &inode_loop_detect);
327 PR_3_ALLOCATE_IBITMAP_ERROR, pctx);
328 ctx->flags |= E2F_FLAG_ABORT;
337 * Make sure that .. and the parent directory are the same;
338 * offer to fix it if not.
341 if (e2fsck_dir_info_get_dotdot(ctx, dir, &pctx->ino2) ||
342 e2fsck_dir_info_get_parent(ctx, dir, &pctx->dir)) {
343 fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
346 if (pctx->ino2 != pctx->dir) {
347 if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx))
348 fix_dotdot(ctx, dir, pctx->dir);
354 * This routine gets the lost_and_found inode, making it a directory
357 ext2_ino_t e2fsck_get_lost_and_found(e2fsck_t ctx, int fix)
359 ext2_filsys fs = ctx->fs;
363 struct ext2_inode inode;
365 static const char name[] = "lost+found";
366 struct problem_context pctx;
368 if (ctx->lost_and_found)
369 return ctx->lost_and_found;
371 clear_problem_context(&pctx);
373 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
374 sizeof(name)-1, 0, &ino);
378 if (ext2fs_test_inode_bitmap2(ctx->inode_dir_map, ino)) {
379 ctx->lost_and_found = ino;
383 /* Lost+found isn't a directory! */
387 if (!fix_problem(ctx, PR_3_LPF_NOTDIR, &pctx))
390 /* OK, unlink the old /lost+found file. */
391 pctx.errcode = ext2fs_unlink(fs, EXT2_ROOT_INO, name, ino, 0);
393 pctx.str = "ext2fs_unlink";
394 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
397 (void) e2fsck_dir_info_set_parent(ctx, ino, 0);
398 e2fsck_adjust_inode_count(ctx, ino, -1);
399 } else if (retval != EXT2_ET_FILE_NOT_FOUND) {
400 pctx.errcode = retval;
401 fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx);
403 if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0))
407 * Read the inode and block bitmaps in; we'll be messing with
410 e2fsck_read_bitmaps(ctx);
413 * First, find a free block
415 retval = ext2fs_new_block2(fs, 0, ctx->block_found_map, &blk);
417 pctx.errcode = retval;
418 fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx);
421 ext2fs_mark_block_bitmap2(ctx->block_found_map, blk);
422 ext2fs_block_alloc_stats2(fs, blk, +1);
425 * Next find a free inode.
427 retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040700,
428 ctx->inode_used_map, &ino);
430 pctx.errcode = retval;
431 fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx);
434 ext2fs_mark_inode_bitmap2(ctx->inode_used_map, ino);
435 ext2fs_mark_inode_bitmap2(ctx->inode_dir_map, ino);
436 ext2fs_inode_alloc_stats2(fs, ino, +1, 1);
439 * Now let's create the actual data block for the inode
441 retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block);
443 pctx.errcode = retval;
444 fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx);
448 retval = ext2fs_write_dir_block4(fs, blk, block, 0, ino);
449 ext2fs_free_mem(&block);
451 pctx.errcode = retval;
452 fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx);
457 * Set up the inode structure
459 memset(&inode, 0, sizeof(inode));
460 inode.i_mode = 040700;
461 inode.i_size = fs->blocksize;
462 inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now;
463 inode.i_links_count = 2;
464 ext2fs_iblk_set(fs, &inode, 1);
465 inode.i_block[0] = blk;
468 * Next, write out the inode.
470 pctx.errcode = ext2fs_write_new_inode(fs, ino, &inode);
472 pctx.str = "ext2fs_write_inode";
473 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
477 * Finally, create the directory link
479 pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, EXT2_FT_DIR);
481 pctx.str = "ext2fs_link";
482 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
487 * Miscellaneous bookkeeping that needs to be kept straight.
489 e2fsck_add_dir_info(ctx, ino, EXT2_ROOT_INO);
490 e2fsck_adjust_inode_count(ctx, EXT2_ROOT_INO, 1);
491 ext2fs_icount_store(ctx->inode_count, ino, 2);
492 ext2fs_icount_store(ctx->inode_link_info, ino, 2);
493 ctx->lost_and_found = ino;
494 quota_data_add(ctx->qctx, &inode, ino, fs->blocksize);
495 quota_data_inodes(ctx->qctx, &inode, ino, +1);
497 printf("/lost+found created; inode #%lu\n", ino);
503 * This routine will connect a file to lost+found
505 int e2fsck_reconnect_file(e2fsck_t ctx, ext2_ino_t ino)
507 ext2_filsys fs = ctx->fs;
510 struct problem_context pctx;
511 struct ext2_inode inode;
514 clear_problem_context(&pctx);
517 if (!ctx->bad_lost_and_found && !ctx->lost_and_found) {
518 if (e2fsck_get_lost_and_found(ctx, 1) == 0)
519 ctx->bad_lost_and_found++;
521 if (ctx->bad_lost_and_found) {
522 fix_problem(ctx, PR_3_NO_LPF, &pctx);
526 sprintf(name, "#%u", ino);
527 if (ext2fs_read_inode(fs, ino, &inode) == 0)
528 file_type = ext2_file_type(inode.i_mode);
529 retval = ext2fs_link(fs, ctx->lost_and_found, name, ino, file_type);
530 if (retval == EXT2_ET_DIR_NO_SPACE) {
531 if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx))
533 retval = e2fsck_expand_directory(ctx, ctx->lost_and_found,
536 pctx.errcode = retval;
537 fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx);
540 retval = ext2fs_link(fs, ctx->lost_and_found, name,
544 pctx.errcode = retval;
545 fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx);
548 e2fsck_adjust_inode_count(ctx, ino, 1);
554 * Utility routine to adjust the inode counts on an inode.
556 errcode_t e2fsck_adjust_inode_count(e2fsck_t ctx, ext2_ino_t ino, int adj)
558 ext2_filsys fs = ctx->fs;
560 struct ext2_inode inode;
565 retval = ext2fs_read_inode(fs, ino, &inode);
570 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
571 inode.i_links_count);
575 ext2fs_icount_increment(ctx->inode_count, ino, 0);
576 if (inode.i_links_count == (__u16) ~0)
578 ext2fs_icount_increment(ctx->inode_link_info, ino, 0);
579 inode.i_links_count++;
580 } else if (adj == -1) {
581 ext2fs_icount_decrement(ctx->inode_count, ino, 0);
582 if (inode.i_links_count == 0)
584 ext2fs_icount_decrement(ctx->inode_link_info, ino, 0);
585 inode.i_links_count--;
588 retval = ext2fs_write_inode(fs, ino, &inode);
596 * Fix parent --- this routine fixes up the parent of a directory.
598 struct fix_dotdot_struct {
605 static int fix_dotdot_proc(struct ext2_dir_entry *dirent,
606 int offset EXT2FS_ATTR((unused)),
607 int blocksize EXT2FS_ATTR((unused)),
608 char *buf EXT2FS_ATTR((unused)),
611 struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) priv_data;
613 struct problem_context pctx;
615 if ((dirent->name_len & 0xFF) != 2)
617 if (strncmp(dirent->name, "..", 2))
620 clear_problem_context(&pctx);
622 retval = e2fsck_adjust_inode_count(fp->ctx, dirent->inode, -1);
624 pctx.errcode = retval;
625 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
627 retval = e2fsck_adjust_inode_count(fp->ctx, fp->parent, 1);
629 pctx.errcode = retval;
630 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
632 dirent->inode = fp->parent;
633 if (fp->ctx->fs->super->s_feature_incompat &
634 EXT2_FEATURE_INCOMPAT_FILETYPE)
635 dirent->name_len = (dirent->name_len & 0xFF) |
638 dirent->name_len = dirent->name_len & 0xFF;
641 return DIRENT_ABORT | DIRENT_CHANGED;
644 static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
646 ext2_filsys fs = ctx->fs;
648 struct fix_dotdot_struct fp;
649 struct problem_context pctx;
657 printf("Fixing '..' of inode %lu to be %lu...\n", ino, parent);
660 clear_problem_context(&pctx);
662 if (e2fsck_dir_will_be_rehashed(ctx, ino))
663 ctx->fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
664 retval = ext2fs_dir_iterate(fs, ino, DIRENT_FLAG_INCLUDE_EMPTY,
665 0, fix_dotdot_proc, &fp);
666 if (e2fsck_dir_will_be_rehashed(ctx, ino))
667 ctx->fs->flags &= ~EXT2_FLAG_IGNORE_CSUM_ERRORS;
668 if (retval || !fp.done) {
669 pctx.errcode = retval;
670 fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR :
671 PR_3_FIX_PARENT_NOFIND, &pctx);
672 ext2fs_unmark_valid(fs);
674 (void) e2fsck_dir_info_set_dotdot(ctx, ino, parent);
675 if (e2fsck_dir_info_set_parent(ctx, ino, ctx->lost_and_found))
676 fix_problem(ctx, PR_3_NO_DIRINFO, &pctx);
682 * These routines are responsible for expanding a /lost+found if it is
686 struct expand_dir_struct {
688 e2_blkcnt_t guaranteed_size;
696 static int expand_dir_proc(ext2_filsys fs,
698 e2_blkcnt_t blockcnt,
699 blk64_t ref_block EXT2FS_ATTR((unused)),
700 int ref_offset EXT2FS_ATTR((unused)),
703 struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
705 static blk64_t last_blk = 0;
712 if (es->guaranteed_size && blockcnt >= es->guaranteed_size)
716 es->last_block = blockcnt;
721 retval = ext2fs_new_block2(fs, last_blk, ctx->block_found_map,
728 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
734 retval = ext2fs_write_dir_block4(fs, new_blk, block, 0,
737 retval = ext2fs_get_mem(fs->blocksize, &block);
742 memset(block, 0, fs->blocksize);
743 retval = io_channel_write_blk64(fs->io, new_blk, 1, block);
749 ext2fs_free_mem(&block);
751 ext2fs_mark_block_bitmap2(ctx->block_found_map, new_blk);
752 ext2fs_block_alloc_stats2(fs, new_blk, +1);
756 return (BLOCK_CHANGED | BLOCK_ABORT);
758 return BLOCK_CHANGED;
761 errcode_t e2fsck_expand_directory(e2fsck_t ctx, ext2_ino_t dir,
762 int num, int guaranteed_size)
764 ext2_filsys fs = ctx->fs;
766 struct expand_dir_struct es;
767 struct ext2_inode inode;
769 if (!(fs->flags & EXT2_FLAG_RW))
770 return EXT2_ET_RO_FILSYS;
773 * Read the inode and block bitmaps in; we'll be messing with
776 e2fsck_read_bitmaps(ctx);
778 retval = ext2fs_check_directory(fs, dir);
783 es.guaranteed_size = guaranteed_size;
790 retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_APPEND,
791 0, expand_dir_proc, &es);
797 * Update the size and block count fields in the inode.
799 retval = ext2fs_read_inode(fs, dir, &inode);
803 inode.i_size = (es.last_block + 1) * fs->blocksize;
804 ext2fs_iblk_add_blocks(fs, &inode, es.newblocks);
805 quota_data_add(ctx->qctx, &inode, dir, es.newblocks * fs->blocksize);
807 e2fsck_write_inode(ctx, dir, &inode, "expand_directory");