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.
44 static void check_root(e2fsck_t ctx);
45 static int check_directory(e2fsck_t ctx, struct dir_info *dir,
46 struct problem_context *pctx);
47 static ext2_ino_t get_lost_and_found(e2fsck_t ctx);
48 static void fix_dotdot(e2fsck_t ctx, struct dir_info *dir, ext2_ino_t parent);
49 static errcode_t adjust_inode_count(e2fsck_t ctx, ext2_ino_t ino, int adj);
51 static ext2_ino_t lost_and_found = 0;
52 static int bad_lost_and_found = 0;
54 static ext2fs_inode_bitmap inode_loop_detect = 0;
55 static ext2fs_inode_bitmap inode_done_map = 0;
57 void e2fsck_pass3(e2fsck_t ctx)
59 ext2_filsys fs = ctx->fs;
62 struct resource_track rtrack;
64 struct problem_context pctx;
66 unsigned long maxdirs, count;
69 init_resource_track(&rtrack);
72 clear_problem_context(&pctx);
75 mtrace_print("Pass 3");
78 if (!(ctx->options & E2F_OPT_PREEN))
79 fix_problem(ctx, PR_3_PASS_HEADER, &pctx);
82 * Allocate some bitmaps to do loop detection.
84 pctx.errcode = ext2fs_allocate_inode_bitmap(fs, _("inode done bitmap"),
88 fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx);
89 ctx->flags |= E2F_FLAG_ABORT;
93 if (ctx->options & E2F_OPT_TIME) {
94 e2fsck_clear_progbar(ctx);
95 print_resource_track(_("Peak memory"), &ctx->global_rtrack);
100 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
103 ext2fs_mark_inode_bitmap(inode_done_map, EXT2_ROOT_INO);
105 maxdirs = e2fsck_get_num_dirinfo(ctx);
109 if ((ctx->progress)(ctx, 3, 0, maxdirs))
112 for (i=0; (dir = e2fsck_dir_info_iter(ctx, &i)) != 0;) {
113 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
115 if (ctx->progress && (ctx->progress)(ctx, 3, count++, maxdirs))
117 if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, dir->ino))
118 if (check_directory(ctx, dir, &pctx))
123 * Force the creation of /lost+found if not present
125 if ((ctx->flags & E2F_OPT_READONLY) == 0)
126 get_lost_and_found(ctx);
129 e2fsck_free_dir_info(ctx);
130 if (inode_loop_detect) {
131 ext2fs_free_inode_bitmap(inode_loop_detect);
132 inode_loop_detect = 0;
134 if (inode_done_map) {
135 ext2fs_free_inode_bitmap(inode_done_map);
139 /* If there are any directories that need to be indexed, do it here. */
140 if (ctx->dirs_to_hash)
141 e2fsck_rehash_directories(ctx);
143 #ifdef RESOURCE_TRACK
144 if (ctx->options & E2F_OPT_TIME2) {
145 e2fsck_clear_progbar(ctx);
146 print_resource_track(_("Pass 3"), &rtrack);
152 * This makes sure the root inode is present; if not, we ask if the
153 * user wants us to create it. Not creating it is a fatal error.
155 static void check_root(e2fsck_t ctx)
157 ext2_filsys fs = ctx->fs;
159 struct ext2_inode inode;
161 struct problem_context pctx;
163 clear_problem_context(&pctx);
165 if (ext2fs_test_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO)) {
167 * If the root inode is not a directory, die here. The
168 * user must have answered 'no' in pass1 when we
169 * offered to clear it.
171 if (!(ext2fs_test_inode_bitmap(ctx->inode_dir_map,
173 fix_problem(ctx, PR_3_ROOT_NOT_DIR_ABORT, &pctx);
174 ctx->flags |= E2F_FLAG_ABORT;
179 if (!fix_problem(ctx, PR_3_NO_ROOT_INODE, &pctx)) {
180 fix_problem(ctx, PR_3_NO_ROOT_INODE_ABORT, &pctx);
181 ctx->flags |= E2F_FLAG_ABORT;
185 e2fsck_read_bitmaps(ctx);
188 * First, find a free block
190 pctx.errcode = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
192 pctx.str = "ext2fs_new_block";
193 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
194 ctx->flags |= E2F_FLAG_ABORT;
197 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
198 ext2fs_mark_block_bitmap(fs->block_map, blk);
199 ext2fs_mark_bb_dirty(fs);
202 * Now let's create the actual data block for the inode
204 pctx.errcode = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO,
207 pctx.str = "ext2fs_new_dir_block";
208 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
209 ctx->flags |= E2F_FLAG_ABORT;
213 pctx.errcode = ext2fs_write_dir_block(fs, blk, block);
215 pctx.str = "ext2fs_write_dir_block";
216 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
217 ctx->flags |= E2F_FLAG_ABORT;
220 ext2fs_free_mem((void **) &block);
223 * Set up the inode structure
225 memset(&inode, 0, sizeof(inode));
226 inode.i_mode = 040755;
227 inode.i_size = fs->blocksize;
228 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
229 inode.i_links_count = 2;
230 inode.i_blocks = fs->blocksize / 512;
231 inode.i_block[0] = blk;
234 * Write out the inode.
236 pctx.errcode = ext2fs_write_inode(fs, EXT2_ROOT_INO, &inode);
238 pctx.str = "ext2fs_write_inode";
239 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
240 ctx->flags |= E2F_FLAG_ABORT;
245 * Miscellaneous bookkeeping...
247 e2fsck_add_dir_info(ctx, EXT2_ROOT_INO, EXT2_ROOT_INO);
248 ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2);
249 ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2);
251 ext2fs_mark_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO);
252 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, EXT2_ROOT_INO);
253 ext2fs_mark_inode_bitmap(fs->inode_map, EXT2_ROOT_INO);
254 ext2fs_mark_ib_dirty(fs);
258 * This subroutine is responsible for making sure that a particular
259 * directory is connected to the root; if it isn't we trace it up as
260 * far as we can go, and then offer to connect the resulting parent to
261 * the lost+found. We have to do loop detection; if we ever discover
262 * a loop, we treat that as a disconnected directory and offer to
263 * reparent it to lost+found.
265 * However, loop detection is expensive, because for very large
266 * filesystems, the inode_loop_detect bitmap is huge, and clearing it
267 * is non-trivial. Loops in filesystems are also a rare error case,
268 * and we shouldn't optimize for error cases. So we try two passes of
269 * the algorithm. The first time, we ignore loop detection and merely
270 * increment a counter; if the counter exceeds some extreme threshold,
271 * then we try again with the loop detection bitmap enabled.
273 static int check_directory(e2fsck_t ctx, struct dir_info *dir,
274 struct problem_context *pctx)
276 ext2_filsys fs = ctx->fs;
277 struct dir_info *p = dir;
278 int loop_pass = 0, parent_count = 0;
285 * Mark this inode as being "done"; by the time we
286 * return from this function, the inode we either be
287 * verified as being connected to the directory tree,
288 * or we will have offered to reconnect this to
291 * If it was marked done already, then we've reached a
292 * parent we've already checked.
294 if (ext2fs_mark_inode_bitmap(inode_done_map, p->ino))
298 * If this directory doesn't have a parent, or we've
299 * seen the parent once already, then offer to
300 * reparent it to lost+found
304 (ext2fs_test_inode_bitmap(inode_loop_detect,
307 if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) {
308 if (e2fsck_reconnect_file(ctx, p->ino))
309 ext2fs_unmark_valid(fs);
311 p->parent = lost_and_found;
312 fix_dotdot(ctx, p, lost_and_found);
317 p = e2fsck_get_dir_info(ctx, p->parent);
319 fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
323 ext2fs_mark_inode_bitmap(inode_loop_detect,
325 } else if (parent_count++ > 2048) {
327 * If we've run into a path depth that's
328 * greater than 2048, try again with the inode
329 * loop bitmap turned on and start from the
333 if (inode_loop_detect)
334 ext2fs_clear_inode_bitmap(inode_loop_detect);
336 pctx->errcode = ext2fs_allocate_inode_bitmap(fs, _("inode loop detection bitmap"), &inode_loop_detect);
340 PR_3_ALLOCATE_IBITMAP_ERROR, pctx);
341 ctx->flags |= E2F_FLAG_ABORT;
350 * Make sure that .. and the parent directory are the same;
351 * offer to fix it if not.
353 if (dir->parent != dir->dotdot) {
354 pctx->ino = dir->ino;
355 pctx->ino2 = dir->dotdot;
356 pctx->dir = dir->parent;
357 if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx))
358 fix_dotdot(ctx, dir, dir->parent);
364 * This routine gets the lost_and_found inode, making it a directory
367 static ext2_ino_t get_lost_and_found(e2fsck_t ctx)
369 ext2_filsys fs = ctx->fs;
373 struct ext2_inode inode;
375 static const char name[] = "lost+found";
376 struct problem_context pctx;
377 struct dir_info *dirinfo;
379 clear_problem_context(&pctx);
381 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
382 sizeof(name)-1, 0, &ino);
384 if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, ino))
386 /* Lost+found isn't a directory! */
388 if (!fix_problem(ctx, PR_3_LPF_NOTDIR, &pctx))
391 /* OK, unlink the old /lost+found file. */
392 pctx.errcode = ext2fs_unlink(fs, EXT2_ROOT_INO, name, ino, 0);
394 pctx.str = "ext2fs_unlink";
395 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
398 dirinfo = e2fsck_get_dir_info(ctx, ino);
401 adjust_inode_count(ctx, ino, -1);
402 } else if (retval != EXT2_ET_FILE_NOT_FOUND) {
403 pctx.errcode = retval;
404 fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx);
406 if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0))
410 * Read the inode and block bitmaps in; we'll be messing with
413 e2fsck_read_bitmaps(ctx);
416 * First, find a free block
418 retval = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
420 pctx.errcode = retval;
421 fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx);
424 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
425 ext2fs_mark_block_bitmap(fs->block_map, blk);
426 ext2fs_mark_bb_dirty(fs);
429 * Next find a free inode.
431 retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040755,
432 ctx->inode_used_map, &ino);
434 pctx.errcode = retval;
435 fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx);
438 ext2fs_mark_inode_bitmap(ctx->inode_used_map, ino);
439 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, ino);
440 ext2fs_mark_inode_bitmap(fs->inode_map, ino);
441 ext2fs_mark_ib_dirty(fs);
444 * Now let's create the actual data block for the inode
446 retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block);
448 pctx.errcode = retval;
449 fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx);
453 retval = ext2fs_write_dir_block(fs, blk, block);
454 ext2fs_free_mem((void **) &block);
456 pctx.errcode = retval;
457 fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx);
462 * Set up the inode structure
464 memset(&inode, 0, sizeof(inode));
465 inode.i_mode = 040755;
466 inode.i_size = fs->blocksize;
467 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
468 inode.i_links_count = 2;
469 inode.i_blocks = fs->blocksize / 512;
470 inode.i_block[0] = blk;
473 * Next, write out the inode.
475 pctx.errcode = ext2fs_write_inode(fs, ino, &inode);
477 pctx.str = "ext2fs_write_inode";
478 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
482 * Finally, create the directory link
484 pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, EXT2_FT_DIR);
486 pctx.str = "ext2fs_link";
487 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
492 * Miscellaneous bookkeeping that needs to be kept straight.
494 e2fsck_add_dir_info(ctx, ino, EXT2_ROOT_INO);
495 adjust_inode_count(ctx, EXT2_ROOT_INO, 1);
496 ext2fs_icount_store(ctx->inode_count, ino, 2);
497 ext2fs_icount_store(ctx->inode_link_info, ino, 2);
499 printf("/lost+found created; inode #%lu\n", ino);
505 * This routine will connect a file to lost+found
507 int e2fsck_reconnect_file(e2fsck_t ctx, ext2_ino_t ino)
509 ext2_filsys fs = ctx->fs;
512 struct problem_context pctx;
513 struct ext2_inode inode;
516 clear_problem_context(&pctx);
519 if (!bad_lost_and_found && !lost_and_found) {
520 lost_and_found = get_lost_and_found(ctx);
522 bad_lost_and_found++;
524 if (bad_lost_and_found) {
525 fix_problem(ctx, PR_3_NO_LPF, &pctx);
529 sprintf(name, "#%u", ino);
530 if (ext2fs_read_inode(fs, ino, &inode) == 0)
531 file_type = ext2_file_type(inode.i_mode);
532 retval = ext2fs_link(fs, lost_and_found, name, ino, file_type);
533 if (retval == EXT2_ET_DIR_NO_SPACE) {
534 if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx))
536 retval = e2fsck_expand_directory(ctx, lost_and_found, 1, 0);
538 pctx.errcode = retval;
539 fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx);
542 retval = ext2fs_link(fs, lost_and_found, name, ino, file_type);
545 pctx.errcode = retval;
546 fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx);
549 adjust_inode_count(ctx, ino, 1);
555 * Utility routine to adjust the inode counts on an inode.
557 static errcode_t adjust_inode_count(e2fsck_t ctx, ext2_ino_t ino, int adj)
559 ext2_filsys fs = ctx->fs;
561 struct ext2_inode inode;
566 retval = ext2fs_read_inode(fs, ino, &inode);
571 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
572 inode.i_links_count);
576 ext2fs_icount_increment(ctx->inode_count, ino, 0);
577 if (inode.i_links_count == (__u16) ~0)
579 ext2fs_icount_increment(ctx->inode_link_info, ino, 0);
580 inode.i_links_count++;
581 } else if (adj == -1) {
582 ext2fs_icount_decrement(ctx->inode_count, ino, 0);
583 if (inode.i_links_count == 0)
585 ext2fs_icount_decrement(ctx->inode_link_info, ino, 0);
586 inode.i_links_count--;
588 /* Should never happen */
589 fatal_error(ctx, _("Debug error in e2fsck adjust_inode_count, "
590 "should never happen.\n"));
593 retval = ext2fs_write_inode(fs, ino, &inode);
601 * Fix parent --- this routine fixes up the parent of a directory.
603 struct fix_dotdot_struct {
610 static int fix_dotdot_proc(struct ext2_dir_entry *dirent,
616 struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) priv_data;
618 struct problem_context pctx;
620 if ((dirent->name_len & 0xFF) != 2)
622 if (strncmp(dirent->name, "..", 2))
625 clear_problem_context(&pctx);
627 retval = adjust_inode_count(fp->ctx, dirent->inode, -1);
629 pctx.errcode = retval;
630 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
632 retval = adjust_inode_count(fp->ctx, fp->parent, 1);
634 pctx.errcode = retval;
635 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
637 dirent->inode = fp->parent;
640 return DIRENT_ABORT | DIRENT_CHANGED;
643 static void fix_dotdot(e2fsck_t ctx, struct dir_info *dir, ext2_ino_t parent)
645 ext2_filsys fs = ctx->fs;
647 struct fix_dotdot_struct fp;
648 struct problem_context pctx;
656 printf("Fixing '..' of inode %lu to be %lu...\n", dir->ino, parent);
659 retval = ext2fs_dir_iterate(fs, dir->ino, DIRENT_FLAG_INCLUDE_EMPTY,
660 0, fix_dotdot_proc, &fp);
661 if (retval || !fp.done) {
662 clear_problem_context(&pctx);
664 pctx.errcode = retval;
665 fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR :
666 PR_3_FIX_PARENT_NOFIND, &pctx);
667 ext2fs_unmark_valid(fs);
669 dir->dotdot = parent;
675 * These routines are responsible for expanding a /lost+found if it is
679 struct expand_dir_struct {
688 static int expand_dir_proc(ext2_filsys fs,
690 e2_blkcnt_t blockcnt,
695 struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
697 static blk_t last_blk = 0;
704 if (es->guaranteed_size && blockcnt >= es->guaranteed_size)
708 es->last_block = blockcnt;
713 retval = ext2fs_new_block(fs, last_blk, ctx->block_found_map,
720 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
726 retval = ext2fs_write_dir_block(fs, new_blk, block);
728 retval = ext2fs_get_mem(fs->blocksize, (void **) &block);
733 memset(block, 0, fs->blocksize);
734 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
740 ext2fs_free_mem((void **) &block);
742 ext2fs_mark_block_bitmap(ctx->block_found_map, new_blk);
743 ext2fs_block_alloc_stats(fs, new_blk, +1);
747 return (BLOCK_CHANGED | BLOCK_ABORT);
749 return BLOCK_CHANGED;
752 errcode_t e2fsck_expand_directory(e2fsck_t ctx, ext2_ino_t dir,
753 int num, int guaranteed_size)
755 ext2_filsys fs = ctx->fs;
757 struct expand_dir_struct es;
758 struct ext2_inode inode;
760 if (!(fs->flags & EXT2_FLAG_RW))
761 return EXT2_ET_RO_FILSYS;
764 * Read the inode and block bitmaps in; we'll be messing with
767 e2fsck_read_bitmaps(ctx);
769 retval = ext2fs_check_directory(fs, dir);
774 es.guaranteed_size = guaranteed_size;
780 retval = ext2fs_block_iterate2(fs, dir, BLOCK_FLAG_APPEND,
781 0, expand_dir_proc, &es);
787 * Update the size and block count fields in the inode.
789 retval = ext2fs_read_inode(fs, dir, &inode);
793 inode.i_size = (es.last_block + 1) * fs->blocksize;
794 inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
796 e2fsck_write_inode(ctx, dir, &inode, "expand_directory");