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_block(fs, blk, block);
203 pctx.str = "ext2fs_write_dir_block";
204 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
205 ctx->flags |= E2F_FLAG_ABORT;
208 ext2fs_free_mem(&block);
211 * Set up the inode structure
213 memset(&inode, 0, sizeof(inode));
214 inode.i_mode = 040755;
215 inode.i_size = fs->blocksize;
216 inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now;
217 inode.i_links_count = 2;
218 ext2fs_iblk_set(fs, &inode, 1);
219 inode.i_block[0] = blk;
222 * Write out the inode.
224 pctx.errcode = ext2fs_write_new_inode(fs, EXT2_ROOT_INO, &inode);
226 pctx.str = "ext2fs_write_inode";
227 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
228 ctx->flags |= E2F_FLAG_ABORT;
233 * Miscellaneous bookkeeping...
235 e2fsck_add_dir_info(ctx, EXT2_ROOT_INO, EXT2_ROOT_INO);
236 ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2);
237 ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2);
239 ext2fs_mark_inode_bitmap2(ctx->inode_used_map, EXT2_ROOT_INO);
240 ext2fs_mark_inode_bitmap2(ctx->inode_dir_map, EXT2_ROOT_INO);
241 ext2fs_mark_inode_bitmap2(fs->inode_map, EXT2_ROOT_INO);
242 ext2fs_mark_ib_dirty(fs);
246 * This subroutine is responsible for making sure that a particular
247 * directory is connected to the root; if it isn't we trace it up as
248 * far as we can go, and then offer to connect the resulting parent to
249 * the lost+found. We have to do loop detection; if we ever discover
250 * a loop, we treat that as a disconnected directory and offer to
251 * reparent it to lost+found.
253 * However, loop detection is expensive, because for very large
254 * filesystems, the inode_loop_detect bitmap is huge, and clearing it
255 * is non-trivial. Loops in filesystems are also a rare error case,
256 * and we shouldn't optimize for error cases. So we try two passes of
257 * the algorithm. The first time, we ignore loop detection and merely
258 * increment a counter; if the counter exceeds some extreme threshold,
259 * then we try again with the loop detection bitmap enabled.
261 static int check_directory(e2fsck_t ctx, ext2_ino_t dir,
262 struct problem_context *pctx)
264 ext2_filsys fs = ctx->fs;
265 ext2_ino_t ino = dir, parent;
266 int loop_pass = 0, parent_count = 0;
270 * Mark this inode as being "done"; by the time we
271 * return from this function, the inode we either be
272 * verified as being connected to the directory tree,
273 * or we will have offered to reconnect this to
276 * If it was marked done already, then we've reached a
277 * parent we've already checked.
279 if (ext2fs_mark_inode_bitmap2(inode_done_map, ino))
282 if (e2fsck_dir_info_get_parent(ctx, ino, &parent)) {
283 fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
288 * If this directory doesn't have a parent, or we've
289 * seen the parent once already, then offer to
290 * reparent it to lost+found
294 (ext2fs_test_inode_bitmap2(inode_loop_detect,
297 if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) {
298 if (e2fsck_reconnect_file(ctx, pctx->ino))
299 ext2fs_unmark_valid(fs);
301 fix_dotdot(ctx, pctx->ino,
302 ctx->lost_and_found);
303 parent = ctx->lost_and_found;
310 ext2fs_mark_inode_bitmap2(inode_loop_detect, ino);
311 } else if (parent_count++ > 2048) {
313 * If we've run into a path depth that's
314 * greater than 2048, try again with the inode
315 * loop bitmap turned on and start from the
319 if (inode_loop_detect)
320 ext2fs_clear_inode_bitmap(inode_loop_detect);
322 pctx->errcode = e2fsck_allocate_inode_bitmap(fs, _("inode loop detection bitmap"), EXT2FS_BMAP64_AUTODIR, "inode_loop_detect", &inode_loop_detect);
326 PR_3_ALLOCATE_IBITMAP_ERROR, pctx);
327 ctx->flags |= E2F_FLAG_ABORT;
336 * Make sure that .. and the parent directory are the same;
337 * offer to fix it if not.
340 if (e2fsck_dir_info_get_dotdot(ctx, dir, &pctx->ino2) ||
341 e2fsck_dir_info_get_parent(ctx, dir, &pctx->dir)) {
342 fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
345 if (pctx->ino2 != pctx->dir) {
346 if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx))
347 fix_dotdot(ctx, dir, pctx->dir);
353 * This routine gets the lost_and_found inode, making it a directory
356 ext2_ino_t e2fsck_get_lost_and_found(e2fsck_t ctx, int fix)
358 ext2_filsys fs = ctx->fs;
362 struct ext2_inode inode;
364 static const char name[] = "lost+found";
365 struct problem_context pctx;
367 if (ctx->lost_and_found)
368 return ctx->lost_and_found;
370 clear_problem_context(&pctx);
372 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
373 sizeof(name)-1, 0, &ino);
377 if (ext2fs_test_inode_bitmap2(ctx->inode_dir_map, ino)) {
378 ctx->lost_and_found = ino;
382 /* Lost+found isn't a directory! */
386 if (!fix_problem(ctx, PR_3_LPF_NOTDIR, &pctx))
389 /* OK, unlink the old /lost+found file. */
390 pctx.errcode = ext2fs_unlink(fs, EXT2_ROOT_INO, name, ino, 0);
392 pctx.str = "ext2fs_unlink";
393 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
396 (void) e2fsck_dir_info_set_parent(ctx, ino, 0);
397 e2fsck_adjust_inode_count(ctx, ino, -1);
398 } else if (retval != EXT2_ET_FILE_NOT_FOUND) {
399 pctx.errcode = retval;
400 fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx);
402 if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0))
406 * Read the inode and block bitmaps in; we'll be messing with
409 e2fsck_read_bitmaps(ctx);
412 * First, find a free block
414 retval = ext2fs_new_block2(fs, 0, ctx->block_found_map, &blk);
416 pctx.errcode = retval;
417 fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx);
420 ext2fs_mark_block_bitmap2(ctx->block_found_map, blk);
421 ext2fs_block_alloc_stats2(fs, blk, +1);
424 * Next find a free inode.
426 retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040700,
427 ctx->inode_used_map, &ino);
429 pctx.errcode = retval;
430 fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx);
433 ext2fs_mark_inode_bitmap2(ctx->inode_used_map, ino);
434 ext2fs_mark_inode_bitmap2(ctx->inode_dir_map, ino);
435 ext2fs_inode_alloc_stats2(fs, ino, +1, 1);
438 * Now let's create the actual data block for the inode
440 retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block);
442 pctx.errcode = retval;
443 fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx);
447 retval = ext2fs_write_dir_block(fs, blk, block);
448 ext2fs_free_mem(&block);
450 pctx.errcode = retval;
451 fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx);
456 * Set up the inode structure
458 memset(&inode, 0, sizeof(inode));
459 inode.i_mode = 040700;
460 inode.i_size = fs->blocksize;
461 inode.i_atime = inode.i_ctime = inode.i_mtime = ctx->now;
462 inode.i_links_count = 2;
463 ext2fs_iblk_set(fs, &inode, 1);
464 inode.i_block[0] = blk;
467 * Next, write out the inode.
469 pctx.errcode = ext2fs_write_new_inode(fs, ino, &inode);
471 pctx.str = "ext2fs_write_inode";
472 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
476 * Finally, create the directory link
478 pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, EXT2_FT_DIR);
480 pctx.str = "ext2fs_link";
481 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
486 * Miscellaneous bookkeeping that needs to be kept straight.
488 e2fsck_add_dir_info(ctx, ino, EXT2_ROOT_INO);
489 e2fsck_adjust_inode_count(ctx, EXT2_ROOT_INO, 1);
490 ext2fs_icount_store(ctx->inode_count, ino, 2);
491 ext2fs_icount_store(ctx->inode_link_info, ino, 2);
492 ctx->lost_and_found = ino;
493 quota_data_add(ctx->qctx, &inode, ino, fs->blocksize);
494 quota_data_inodes(ctx->qctx, &inode, ino, +1);
496 printf("/lost+found created; inode #%lu\n", ino);
502 * This routine will connect a file to lost+found
504 int e2fsck_reconnect_file(e2fsck_t ctx, ext2_ino_t ino)
506 ext2_filsys fs = ctx->fs;
509 struct problem_context pctx;
510 struct ext2_inode inode;
513 clear_problem_context(&pctx);
516 if (!ctx->bad_lost_and_found && !ctx->lost_and_found) {
517 if (e2fsck_get_lost_and_found(ctx, 1) == 0)
518 ctx->bad_lost_and_found++;
520 if (ctx->bad_lost_and_found) {
521 fix_problem(ctx, PR_3_NO_LPF, &pctx);
525 sprintf(name, "#%u", ino);
526 if (ext2fs_read_inode(fs, ino, &inode) == 0)
527 file_type = ext2_file_type(inode.i_mode);
528 retval = ext2fs_link(fs, ctx->lost_and_found, name, ino, file_type);
529 if (retval == EXT2_ET_DIR_NO_SPACE) {
530 if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx))
532 retval = e2fsck_expand_directory(ctx, ctx->lost_and_found,
535 pctx.errcode = retval;
536 fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx);
539 retval = ext2fs_link(fs, ctx->lost_and_found, name,
543 pctx.errcode = retval;
544 fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx);
547 e2fsck_adjust_inode_count(ctx, ino, 1);
553 * Utility routine to adjust the inode counts on an inode.
555 errcode_t e2fsck_adjust_inode_count(e2fsck_t ctx, ext2_ino_t ino, int adj)
557 ext2_filsys fs = ctx->fs;
559 struct ext2_inode inode;
564 retval = ext2fs_read_inode(fs, ino, &inode);
569 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
570 inode.i_links_count);
574 ext2fs_icount_increment(ctx->inode_count, ino, 0);
575 if (inode.i_links_count == (__u16) ~0)
577 ext2fs_icount_increment(ctx->inode_link_info, ino, 0);
578 inode.i_links_count++;
579 } else if (adj == -1) {
580 ext2fs_icount_decrement(ctx->inode_count, ino, 0);
581 if (inode.i_links_count == 0)
583 ext2fs_icount_decrement(ctx->inode_link_info, ino, 0);
584 inode.i_links_count--;
587 retval = ext2fs_write_inode(fs, ino, &inode);
595 * Fix parent --- this routine fixes up the parent of a directory.
597 struct fix_dotdot_struct {
604 static int fix_dotdot_proc(struct ext2_dir_entry *dirent,
605 int offset EXT2FS_ATTR((unused)),
606 int blocksize EXT2FS_ATTR((unused)),
607 char *buf EXT2FS_ATTR((unused)),
610 struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) priv_data;
612 struct problem_context pctx;
614 if ((dirent->name_len & 0xFF) != 2)
616 if (strncmp(dirent->name, "..", 2))
619 clear_problem_context(&pctx);
621 retval = e2fsck_adjust_inode_count(fp->ctx, dirent->inode, -1);
623 pctx.errcode = retval;
624 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
626 retval = e2fsck_adjust_inode_count(fp->ctx, fp->parent, 1);
628 pctx.errcode = retval;
629 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
631 dirent->inode = fp->parent;
632 if (fp->ctx->fs->super->s_feature_incompat &
633 EXT2_FEATURE_INCOMPAT_FILETYPE)
634 dirent->name_len = (dirent->name_len & 0xFF) |
637 dirent->name_len = dirent->name_len & 0xFF;
640 return DIRENT_ABORT | DIRENT_CHANGED;
643 static void fix_dotdot(e2fsck_t ctx, ext2_ino_t ino, 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", ino, parent);
659 clear_problem_context(&pctx);
661 retval = ext2fs_dir_iterate(fs, ino, DIRENT_FLAG_INCLUDE_EMPTY,
662 0, fix_dotdot_proc, &fp);
663 if (retval || !fp.done) {
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 (void) e2fsck_dir_info_set_dotdot(ctx, ino, parent);
670 if (e2fsck_dir_info_set_parent(ctx, ino, ctx->lost_and_found))
671 fix_problem(ctx, PR_3_NO_DIRINFO, &pctx);
677 * These routines are responsible for expanding a /lost+found if it is
681 struct expand_dir_struct {
683 e2_blkcnt_t guaranteed_size;
690 static int expand_dir_proc(ext2_filsys fs,
692 e2_blkcnt_t blockcnt,
693 blk64_t ref_block EXT2FS_ATTR((unused)),
694 int ref_offset EXT2FS_ATTR((unused)),
697 struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
699 static blk64_t last_blk = 0;
706 if (es->guaranteed_size && blockcnt >= es->guaranteed_size)
710 es->last_block = blockcnt;
715 retval = ext2fs_new_block2(fs, last_blk, ctx->block_found_map,
722 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
728 retval = ext2fs_write_dir_block(fs, new_blk, block);
730 retval = ext2fs_get_mem(fs->blocksize, &block);
735 memset(block, 0, fs->blocksize);
736 retval = io_channel_write_blk64(fs->io, new_blk, 1, block);
742 ext2fs_free_mem(&block);
744 ext2fs_mark_block_bitmap2(ctx->block_found_map, new_blk);
745 ext2fs_block_alloc_stats2(fs, new_blk, +1);
749 return (BLOCK_CHANGED | BLOCK_ABORT);
751 return BLOCK_CHANGED;
754 errcode_t e2fsck_expand_directory(e2fsck_t ctx, ext2_ino_t dir,
755 int num, int guaranteed_size)
757 ext2_filsys fs = ctx->fs;
759 struct expand_dir_struct es;
760 struct ext2_inode inode;
762 if (!(fs->flags & EXT2_FLAG_RW))
763 return EXT2_ET_RO_FILSYS;
766 * Read the inode and block bitmaps in; we'll be messing with
769 e2fsck_read_bitmaps(ctx);
771 retval = ext2fs_check_directory(fs, dir);
776 es.guaranteed_size = guaranteed_size;
782 retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_APPEND,
783 0, expand_dir_proc, &es);
789 * Update the size and block count fields in the inode.
791 retval = ext2fs_read_inode(fs, dir, &inode);
795 inode.i_size = (es.last_block + 1) * fs->blocksize;
796 ext2fs_iblk_add_blocks(fs, &inode, es.newblocks);
797 quota_data_add(ctx->qctx, &inode, dir, es.newblocks * fs->blocksize);
799 e2fsck_write_inode(ctx, dir, &inode, "expand_directory");