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, ext2_ino_t ino,
46 struct problem_context *pctx);
47 static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent);
49 static ext2fs_inode_bitmap inode_loop_detect = 0;
50 static ext2fs_inode_bitmap inode_done_map = 0;
52 void e2fsck_pass3(e2fsck_t ctx)
54 ext2_filsys fs = ctx->fs;
55 struct dir_info_iter *iter;
57 struct resource_track rtrack;
59 struct problem_context pctx;
61 unsigned long maxdirs, count;
64 init_resource_track(&rtrack, ctx->fs->io);
67 clear_problem_context(&pctx);
70 mtrace_print("Pass 3");
73 if (!(ctx->options & E2F_OPT_PREEN))
74 fix_problem(ctx, PR_3_PASS_HEADER, &pctx);
77 * Allocate some bitmaps to do loop detection.
79 pctx.errcode = ext2fs_allocate_inode_bitmap(fs, _("inode done bitmap"),
83 fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx);
84 ctx->flags |= E2F_FLAG_ABORT;
88 if (ctx->options & E2F_OPT_TIME) {
89 e2fsck_clear_progbar(ctx);
90 print_resource_track(_("Peak memory"), &ctx->global_rtrack,
96 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
99 ext2fs_mark_inode_bitmap(inode_done_map, EXT2_ROOT_INO);
101 maxdirs = e2fsck_get_num_dirinfo(ctx);
105 if ((ctx->progress)(ctx, 3, 0, maxdirs))
108 iter = e2fsck_dir_info_iter_begin(ctx);
109 while ((dir = e2fsck_dir_info_iter(ctx, iter)) != 0) {
110 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
112 if (ctx->progress && (ctx->progress)(ctx, 3, count++, maxdirs))
114 if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, dir->ino))
115 if (check_directory(ctx, dir->ino, &pctx))
118 e2fsck_dir_info_iter_end(ctx, iter);
121 * Force the creation of /lost+found if not present
123 if ((ctx->flags & E2F_OPT_READONLY) == 0)
124 e2fsck_get_lost_and_found(ctx, 1);
127 * If there are any directories that need to be indexed or
128 * optimized, do it here.
130 e2fsck_rehash_directories(ctx);
133 e2fsck_free_dir_info(ctx);
134 if (inode_loop_detect) {
135 ext2fs_free_inode_bitmap(inode_loop_detect);
136 inode_loop_detect = 0;
138 if (inode_done_map) {
139 ext2fs_free_inode_bitmap(inode_done_map);
143 #ifdef RESOURCE_TRACK
144 if (ctx->options & E2F_OPT_TIME2) {
145 e2fsck_clear_progbar(ctx);
146 print_resource_track(_("Pass 3"), &rtrack, ctx->fs->io);
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(&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 = ctx->now;
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_new_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, ext2_ino_t dir,
274 struct problem_context *pctx)
276 ext2_filsys fs = ctx->fs;
277 ext2_ino_t ino = dir, parent;
278 int loop_pass = 0, parent_count = 0;
282 * Mark this inode as being "done"; by the time we
283 * return from this function, the inode we either be
284 * verified as being connected to the directory tree,
285 * or we will have offered to reconnect this to
288 * If it was marked done already, then we've reached a
289 * parent we've already checked.
291 if (ext2fs_mark_inode_bitmap(inode_done_map, ino))
294 if (e2fsck_dir_info_get_parent(ctx, ino, &parent)) {
295 fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
300 * If this directory doesn't have a parent, or we've
301 * seen the parent once already, then offer to
302 * reparent it to lost+found
306 (ext2fs_test_inode_bitmap(inode_loop_detect,
309 if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) {
310 if (e2fsck_reconnect_file(ctx, pctx->ino))
311 ext2fs_unmark_valid(fs);
313 fix_dotdot(ctx, pctx->ino,
314 ctx->lost_and_found);
315 parent = ctx->lost_and_found;
322 ext2fs_mark_inode_bitmap(inode_loop_detect, ino);
323 } else if (parent_count++ > 2048) {
325 * If we've run into a path depth that's
326 * greater than 2048, try again with the inode
327 * loop bitmap turned on and start from the
331 if (inode_loop_detect)
332 ext2fs_clear_inode_bitmap(inode_loop_detect);
334 pctx->errcode = ext2fs_allocate_inode_bitmap(fs, _("inode loop detection bitmap"), &inode_loop_detect);
338 PR_3_ALLOCATE_IBITMAP_ERROR, pctx);
339 ctx->flags |= E2F_FLAG_ABORT;
348 * Make sure that .. and the parent directory are the same;
349 * offer to fix it if not.
352 if (e2fsck_dir_info_get_dotdot(ctx, dir, &pctx->ino2) ||
353 e2fsck_dir_info_get_parent(ctx, dir, &pctx->dir)) {
354 fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
357 if (pctx->ino2 != pctx->dir) {
358 if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx))
359 fix_dotdot(ctx, dir, pctx->dir);
365 * This routine gets the lost_and_found inode, making it a directory
368 ext2_ino_t e2fsck_get_lost_and_found(e2fsck_t ctx, int fix)
370 ext2_filsys fs = ctx->fs;
374 struct ext2_inode inode;
376 static const char name[] = "lost+found";
377 struct problem_context pctx;
379 if (ctx->lost_and_found)
380 return ctx->lost_and_found;
382 clear_problem_context(&pctx);
384 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
385 sizeof(name)-1, 0, &ino);
389 if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, ino)) {
390 ctx->lost_and_found = ino;
394 /* Lost+found isn't a directory! */
398 if (!fix_problem(ctx, PR_3_LPF_NOTDIR, &pctx))
401 /* OK, unlink the old /lost+found file. */
402 pctx.errcode = ext2fs_unlink(fs, EXT2_ROOT_INO, name, ino, 0);
404 pctx.str = "ext2fs_unlink";
405 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
408 (void) e2fsck_dir_info_set_parent(ctx, ino, 0);
409 e2fsck_adjust_inode_count(ctx, ino, -1);
410 } else if (retval != EXT2_ET_FILE_NOT_FOUND) {
411 pctx.errcode = retval;
412 fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx);
414 if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0))
418 * Read the inode and block bitmaps in; we'll be messing with
421 e2fsck_read_bitmaps(ctx);
424 * First, find a free block
426 retval = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
428 pctx.errcode = retval;
429 fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx);
432 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
433 ext2fs_block_alloc_stats(fs, blk, +1);
436 * Next find a free inode.
438 retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040700,
439 ctx->inode_used_map, &ino);
441 pctx.errcode = retval;
442 fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx);
445 ext2fs_mark_inode_bitmap(ctx->inode_used_map, ino);
446 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, ino);
447 ext2fs_inode_alloc_stats2(fs, ino, +1, 1);
450 * Now let's create the actual data block for the inode
452 retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block);
454 pctx.errcode = retval;
455 fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx);
459 retval = ext2fs_write_dir_block(fs, blk, block);
460 ext2fs_free_mem(&block);
462 pctx.errcode = retval;
463 fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx);
468 * Set up the inode structure
470 memset(&inode, 0, sizeof(inode));
471 inode.i_mode = 040700;
472 inode.i_size = fs->blocksize;
473 inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now;
474 inode.i_links_count = 2;
475 inode.i_blocks = fs->blocksize / 512;
476 inode.i_block[0] = blk;
479 * Next, write out the inode.
481 pctx.errcode = ext2fs_write_new_inode(fs, ino, &inode);
483 pctx.str = "ext2fs_write_inode";
484 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
488 * Finally, create the directory link
490 pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, EXT2_FT_DIR);
492 pctx.str = "ext2fs_link";
493 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
498 * Miscellaneous bookkeeping that needs to be kept straight.
500 e2fsck_add_dir_info(ctx, ino, EXT2_ROOT_INO);
501 e2fsck_adjust_inode_count(ctx, EXT2_ROOT_INO, 1);
502 ext2fs_icount_store(ctx->inode_count, ino, 2);
503 ext2fs_icount_store(ctx->inode_link_info, ino, 2);
504 ctx->lost_and_found = ino;
506 printf("/lost+found created; inode #%lu\n", ino);
512 * This routine will connect a file to lost+found
514 int e2fsck_reconnect_file(e2fsck_t ctx, ext2_ino_t ino)
516 ext2_filsys fs = ctx->fs;
519 struct problem_context pctx;
520 struct ext2_inode inode;
523 clear_problem_context(&pctx);
526 if (!ctx->bad_lost_and_found && !ctx->lost_and_found) {
527 if (e2fsck_get_lost_and_found(ctx, 1) == 0)
528 ctx->bad_lost_and_found++;
530 if (ctx->bad_lost_and_found) {
531 fix_problem(ctx, PR_3_NO_LPF, &pctx);
535 sprintf(name, "#%u", ino);
536 if (ext2fs_read_inode(fs, ino, &inode) == 0)
537 file_type = ext2_file_type(inode.i_mode);
538 retval = ext2fs_link(fs, ctx->lost_and_found, name, ino, file_type);
539 if (retval == EXT2_ET_DIR_NO_SPACE) {
540 if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx))
542 retval = e2fsck_expand_directory(ctx, ctx->lost_and_found,
545 pctx.errcode = retval;
546 fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx);
549 retval = ext2fs_link(fs, ctx->lost_and_found, name,
553 pctx.errcode = retval;
554 fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx);
557 e2fsck_adjust_inode_count(ctx, ino, 1);
563 * Utility routine to adjust the inode counts on an inode.
565 errcode_t e2fsck_adjust_inode_count(e2fsck_t ctx, ext2_ino_t ino, int adj)
567 ext2_filsys fs = ctx->fs;
569 struct ext2_inode inode;
574 retval = ext2fs_read_inode(fs, ino, &inode);
579 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
580 inode.i_links_count);
584 ext2fs_icount_increment(ctx->inode_count, ino, 0);
585 if (inode.i_links_count == (__u16) ~0)
587 ext2fs_icount_increment(ctx->inode_link_info, ino, 0);
588 inode.i_links_count++;
589 } else if (adj == -1) {
590 ext2fs_icount_decrement(ctx->inode_count, ino, 0);
591 if (inode.i_links_count == 0)
593 ext2fs_icount_decrement(ctx->inode_link_info, ino, 0);
594 inode.i_links_count--;
597 retval = ext2fs_write_inode(fs, ino, &inode);
605 * Fix parent --- this routine fixes up the parent of a directory.
607 struct fix_dotdot_struct {
614 static int fix_dotdot_proc(struct ext2_dir_entry *dirent,
615 int offset EXT2FS_ATTR((unused)),
616 int blocksize EXT2FS_ATTR((unused)),
617 char *buf EXT2FS_ATTR((unused)),
620 struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) priv_data;
622 struct problem_context pctx;
624 if ((dirent->name_len & 0xFF) != 2)
626 if (strncmp(dirent->name, "..", 2))
629 clear_problem_context(&pctx);
631 retval = e2fsck_adjust_inode_count(fp->ctx, dirent->inode, -1);
633 pctx.errcode = retval;
634 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
636 retval = e2fsck_adjust_inode_count(fp->ctx, fp->parent, 1);
638 pctx.errcode = retval;
639 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
641 dirent->inode = fp->parent;
642 if (fp->ctx->fs->super->s_feature_incompat &
643 EXT2_FEATURE_INCOMPAT_FILETYPE)
644 dirent->name_len = (dirent->name_len & 0xFF) |
647 dirent->name_len = dirent->name_len & 0xFF;
650 return DIRENT_ABORT | DIRENT_CHANGED;
653 static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, ext2_ino_t parent)
655 ext2_filsys fs = ctx->fs;
657 struct fix_dotdot_struct fp;
658 struct problem_context pctx;
666 printf("Fixing '..' of inode %lu to be %lu...\n", ino, parent);
669 clear_problem_context(&pctx);
671 retval = ext2fs_dir_iterate(fs, ino, DIRENT_FLAG_INCLUDE_EMPTY,
672 0, fix_dotdot_proc, &fp);
673 if (retval || !fp.done) {
674 pctx.errcode = retval;
675 fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR :
676 PR_3_FIX_PARENT_NOFIND, &pctx);
677 ext2fs_unmark_valid(fs);
679 (void) e2fsck_dir_info_set_dotdot(ctx, ino, parent);
680 if (e2fsck_dir_info_set_parent(ctx, ino, ctx->lost_and_found))
681 fix_problem(ctx, PR_3_NO_DIRINFO, &pctx);
687 * These routines are responsible for expanding a /lost+found if it is
691 struct expand_dir_struct {
700 static int expand_dir_proc(ext2_filsys fs,
702 e2_blkcnt_t blockcnt,
703 blk_t ref_block EXT2FS_ATTR((unused)),
704 int ref_offset EXT2FS_ATTR((unused)),
707 struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
709 static blk_t last_blk = 0;
716 if (es->guaranteed_size && blockcnt >= es->guaranteed_size)
720 es->last_block = blockcnt;
725 retval = ext2fs_new_block(fs, last_blk, ctx->block_found_map,
732 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
738 retval = ext2fs_write_dir_block(fs, new_blk, block);
740 retval = ext2fs_get_mem(fs->blocksize, &block);
745 memset(block, 0, fs->blocksize);
746 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
752 ext2fs_free_mem(&block);
754 ext2fs_mark_block_bitmap(ctx->block_found_map, new_blk);
755 ext2fs_block_alloc_stats(fs, new_blk, +1);
759 return (BLOCK_CHANGED | BLOCK_ABORT);
761 return BLOCK_CHANGED;
764 errcode_t e2fsck_expand_directory(e2fsck_t ctx, ext2_ino_t dir,
765 int num, int guaranteed_size)
767 ext2_filsys fs = ctx->fs;
769 struct expand_dir_struct es;
770 struct ext2_inode inode;
772 if (!(fs->flags & EXT2_FLAG_RW))
773 return EXT2_ET_RO_FILSYS;
776 * Read the inode and block bitmaps in; we'll be messing with
779 e2fsck_read_bitmaps(ctx);
781 retval = ext2fs_check_directory(fs, dir);
786 es.guaranteed_size = guaranteed_size;
792 retval = ext2fs_block_iterate2(fs, dir, BLOCK_FLAG_APPEND,
793 0, expand_dir_proc, &es);
799 * Update the size and block count fields in the inode.
801 retval = ext2fs_read_inode(fs, dir, &inode);
805 inode.i_size = (es.last_block + 1) * fs->blocksize;
806 inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
808 e2fsck_write_inode(ctx, dir, &inode, "expand_directory");