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 ino_t get_lost_and_found(e2fsck_t ctx);
48 static void fix_dotdot(e2fsck_t ctx, struct dir_info *dir, ino_t parent);
49 static errcode_t adjust_inode_count(e2fsck_t ctx, ino_t ino, int adj);
50 static errcode_t expand_directory(e2fsck_t ctx, ino_t dir);
52 static ino_t lost_and_found = 0;
53 static int bad_lost_and_found = 0;
55 static ext2fs_inode_bitmap inode_loop_detect = 0;
56 static ext2fs_inode_bitmap inode_done_map = 0;
58 void e2fsck_pass3(e2fsck_t ctx)
60 ext2_filsys fs = ctx->fs;
63 struct resource_track rtrack;
65 struct problem_context pctx;
67 unsigned long maxdirs, count;
70 init_resource_track(&rtrack);
73 clear_problem_context(&pctx);
76 mtrace_print("Pass 3");
79 if (!(ctx->options & E2F_OPT_PREEN))
80 fix_problem(ctx, PR_3_PASS_HEADER, &pctx);
83 * Allocate some bitmaps to do loop detection.
85 pctx.errcode = ext2fs_allocate_inode_bitmap(fs, _("inode done bitmap"),
89 fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx);
90 ctx->flags |= E2F_FLAG_ABORT;
94 if (ctx->options & E2F_OPT_TIME) {
95 e2fsck_clear_progbar(ctx);
96 print_resource_track(_("Peak memory"), &ctx->global_rtrack);
101 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
104 ext2fs_mark_inode_bitmap(inode_done_map, EXT2_ROOT_INO);
106 maxdirs = e2fsck_get_num_dirinfo(ctx);
110 if ((ctx->progress)(ctx, 3, 0, maxdirs))
113 for (i=0; (dir = e2fsck_dir_info_iter(ctx, &i)) != 0;) {
115 if ((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);
138 #ifdef RESOURCE_TRACK
139 if (ctx->options & E2F_OPT_TIME2) {
140 e2fsck_clear_progbar(ctx);
141 print_resource_track(_("Pass 3"), &rtrack);
147 * This makes sure the root inode is present; if not, we ask if the
148 * user wants us to create it. Not creating it is a fatal error.
150 static void check_root(e2fsck_t ctx)
152 ext2_filsys fs = ctx->fs;
154 struct ext2_inode inode;
156 struct problem_context pctx;
158 clear_problem_context(&pctx);
160 if (ext2fs_test_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO)) {
162 * If the root inode is not a directory, die here. The
163 * user must have answered 'no' in pass1 when we
164 * offered to clear it.
166 if (!(ext2fs_test_inode_bitmap(ctx->inode_dir_map,
168 fix_problem(ctx, PR_3_ROOT_NOT_DIR_ABORT, &pctx);
169 ctx->flags |= E2F_FLAG_ABORT;
174 if (!fix_problem(ctx, PR_3_NO_ROOT_INODE, &pctx)) {
175 fix_problem(ctx, PR_3_NO_ROOT_INODE_ABORT, &pctx);
176 ctx->flags |= E2F_FLAG_ABORT;
180 e2fsck_read_bitmaps(ctx);
183 * First, find a free block
185 pctx.errcode = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
187 pctx.str = "ext2fs_new_block";
188 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
189 ctx->flags |= E2F_FLAG_ABORT;
192 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
193 ext2fs_mark_block_bitmap(fs->block_map, blk);
194 ext2fs_mark_bb_dirty(fs);
197 * Now let's create the actual data block for the inode
199 pctx.errcode = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO,
202 pctx.str = "ext2fs_new_dir_block";
203 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
204 ctx->flags |= E2F_FLAG_ABORT;
208 pctx.errcode = ext2fs_write_dir_block(fs, blk, block);
210 pctx.str = "ext2fs_write_dir_block";
211 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
212 ctx->flags |= E2F_FLAG_ABORT;
215 ext2fs_free_mem((void **) &block);
218 * Set up the inode structure
220 memset(&inode, 0, sizeof(inode));
221 inode.i_mode = 040755;
222 inode.i_size = fs->blocksize;
223 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
224 inode.i_links_count = 2;
225 inode.i_blocks = fs->blocksize / 512;
226 inode.i_block[0] = blk;
229 * Write out the inode.
231 pctx.errcode = ext2fs_write_inode(fs, EXT2_ROOT_INO, &inode);
233 pctx.str = "ext2fs_write_inode";
234 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
235 ctx->flags |= E2F_FLAG_ABORT;
240 * Miscellaneous bookkeeping...
242 e2fsck_add_dir_info(ctx, EXT2_ROOT_INO, EXT2_ROOT_INO);
243 ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2);
244 ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2);
246 ext2fs_mark_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO);
247 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, EXT2_ROOT_INO);
248 ext2fs_mark_inode_bitmap(fs->inode_map, EXT2_ROOT_INO);
249 ext2fs_mark_ib_dirty(fs);
253 * This subroutine is responsible for making sure that a particular
254 * directory is connected to the root; if it isn't we trace it up as
255 * far as we can go, and then offer to connect the resulting parent to
256 * the lost+found. We have to do loop detection; if we ever discover
257 * a loop, we treat that as a disconnected directory and offer to
258 * reparent it to lost+found.
260 * However, loop detection is expensive, because for very large
261 * filesystems, the inode_loop_detect bitmap is huge, and clearing it
262 * is non-trivial. Loops in filesystems are also a rare error case,
263 * and we shouldn't optimize for error cases. So we try two passes of
264 * the algorithm. The first time, we ignore loop detection and merely
265 * increment a counter; if the counter exceeds some extreme threshold,
266 * then we try again with the loop detection bitmap enabled.
268 static int check_directory(e2fsck_t ctx, struct dir_info *dir,
269 struct problem_context *pctx)
271 ext2_filsys fs = ctx->fs;
272 struct dir_info *p = dir;
273 int loop_pass = 0, parent_count = 0;
280 * Mark this inode as being "done"; by the time we
281 * return from this function, the inode we either be
282 * verified as being connected to the directory tree,
283 * or we will have offered to reconnect this to
286 * If it was marked done already, then we've reached a
287 * parent we've already checked.
289 if (ext2fs_mark_inode_bitmap(inode_done_map, p->ino))
293 * If this directory doesn't have a parent, or we've
294 * seen the parent once already, then offer to
295 * reparent it to lost+found
299 (ext2fs_test_inode_bitmap(inode_loop_detect,
302 if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) {
303 if (e2fsck_reconnect_file(ctx, p->ino))
304 ext2fs_unmark_valid(fs);
306 p->parent = lost_and_found;
307 fix_dotdot(ctx, p, lost_and_found);
312 p = e2fsck_get_dir_info(ctx, p->parent);
314 fix_problem(ctx, PR_3_NO_DIRINFO, pctx);
318 ext2fs_mark_inode_bitmap(inode_loop_detect,
320 } else if (parent_count++ > 2048) {
322 * If we've run into a path depth that's
323 * greater than 2048, try again with the inode
324 * loop bitmap turned on and start from the
328 if (inode_loop_detect)
329 ext2fs_clear_inode_bitmap(inode_loop_detect);
331 pctx->errcode = ext2fs_allocate_inode_bitmap(fs, _("inode loop detection bitmap"), &inode_loop_detect);
335 PR_3_ALLOCATE_IBITMAP_ERROR, pctx);
336 ctx->flags |= E2F_FLAG_ABORT;
345 * Make sure that .. and the parent directory are the same;
346 * offer to fix it if not.
348 if (dir->parent != dir->dotdot) {
349 pctx->ino = dir->ino;
350 pctx->ino2 = dir->dotdot;
351 pctx->dir = dir->parent;
352 if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx))
353 fix_dotdot(ctx, dir, dir->parent);
359 * This routine gets the lost_and_found inode, making it a directory
362 ino_t get_lost_and_found(e2fsck_t ctx)
364 ext2_filsys fs = ctx->fs;
368 struct ext2_inode inode;
370 const char name[] = "lost+found";
371 struct problem_context pctx;
372 struct dir_info *dirinfo;
374 clear_problem_context(&pctx);
376 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
377 sizeof(name)-1, 0, &ino);
379 if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, ino))
381 /* Lost+found isn't a directory! */
383 if (!fix_problem(ctx, PR_3_LPF_NOTDIR, &pctx))
386 /* OK, unlink the old /lost+found file. */
387 pctx.errcode = ext2fs_unlink(fs, EXT2_ROOT_INO, name, ino, 0);
389 pctx.str = "ext2fs_unlink";
390 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
393 dirinfo = e2fsck_get_dir_info(ctx, ino);
396 adjust_inode_count(ctx, ino, -1);
397 } else if (retval != EXT2_ET_FILE_NOT_FOUND) {
398 pctx.errcode = retval;
399 fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx);
401 if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0))
405 * Read the inode and block bitmaps in; we'll be messing with
408 e2fsck_read_bitmaps(ctx);
411 * First, find a free block
413 retval = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
415 pctx.errcode = retval;
416 fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx);
419 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
420 ext2fs_mark_block_bitmap(fs->block_map, blk);
421 ext2fs_mark_bb_dirty(fs);
424 * Next find a free inode.
426 retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040755,
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_bitmap(ctx->inode_used_map, ino);
434 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, ino);
435 ext2fs_mark_inode_bitmap(fs->inode_map, ino);
436 ext2fs_mark_ib_dirty(fs);
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_block(fs, blk, block);
449 ext2fs_free_mem((void **) &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 = 040755;
461 inode.i_size = fs->blocksize;
462 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
463 inode.i_links_count = 2;
464 inode.i_blocks = fs->blocksize / 512;
465 inode.i_block[0] = blk;
468 * Next, write out the inode.
470 pctx.errcode = ext2fs_write_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 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);
494 printf("/lost+found created; inode #%lu\n", ino);
500 * This routine will connect a file to lost+found
502 int e2fsck_reconnect_file(e2fsck_t ctx, ino_t ino)
504 ext2_filsys fs = ctx->fs;
507 struct problem_context pctx;
508 struct ext2_inode inode;
511 clear_problem_context(&pctx);
514 if (!bad_lost_and_found && !lost_and_found) {
515 lost_and_found = get_lost_and_found(ctx);
517 bad_lost_and_found++;
519 if (bad_lost_and_found) {
520 fix_problem(ctx, PR_3_NO_LPF, &pctx);
524 sprintf(name, "#%lu", ino);
525 if (ext2fs_read_inode(fs, ino, &inode) == 0)
526 file_type = ext2_file_type(inode.i_mode);
527 retval = ext2fs_link(fs, lost_and_found, name, ino, file_type);
528 if (retval == EXT2_ET_DIR_NO_SPACE) {
529 if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx))
531 retval = expand_directory(ctx, lost_and_found);
533 pctx.errcode = retval;
534 fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx);
537 retval = ext2fs_link(fs, lost_and_found, name, ino, file_type);
540 pctx.errcode = retval;
541 fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx);
544 adjust_inode_count(ctx, ino, +1);
550 * Utility routine to adjust the inode counts on an inode.
552 static errcode_t adjust_inode_count(e2fsck_t ctx, ino_t ino, int adj)
554 ext2_filsys fs = ctx->fs;
556 struct ext2_inode inode;
561 retval = ext2fs_read_inode(fs, ino, &inode);
566 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
567 inode.i_links_count);
571 ext2fs_icount_increment(ctx->inode_count, ino, 0);
572 if (inode.i_links_count == (__u16) ~0)
574 ext2fs_icount_increment(ctx->inode_link_info, ino, 0);
575 inode.i_links_count++;
576 } else if (adj == -1) {
577 ext2fs_icount_decrement(ctx->inode_count, ino, 0);
578 if (inode.i_links_count == 0)
580 ext2fs_icount_decrement(ctx->inode_link_info, ino, 0);
581 inode.i_links_count--;
583 /* Should never happen */
584 fatal_error(ctx, _("Debug error in e2fsck adjust_inode_count, "
585 "should never happen.\n"));
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,
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 = adjust_inode_count(fp->ctx, dirent->inode, -1);
624 pctx.errcode = retval;
625 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
627 retval = 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;
635 return DIRENT_ABORT | DIRENT_CHANGED;
638 static void fix_dotdot(e2fsck_t ctx, struct dir_info *dir, ino_t parent)
640 ext2_filsys fs = ctx->fs;
642 struct fix_dotdot_struct fp;
643 struct problem_context pctx;
651 printf("Fixing '..' of inode %lu to be %lu...\n", dir->ino, parent);
654 retval = ext2fs_dir_iterate(fs, dir->ino, DIRENT_FLAG_INCLUDE_EMPTY,
655 0, fix_dotdot_proc, &fp);
656 if (retval || !fp.done) {
657 clear_problem_context(&pctx);
659 pctx.errcode = retval;
660 fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR :
661 PR_3_FIX_PARENT_NOFIND, &pctx);
662 ext2fs_unmark_valid(fs);
664 dir->dotdot = parent;
670 * These routines are responsible for expanding a /lost+found if it is
674 struct expand_dir_struct {
681 static int expand_dir_proc(ext2_filsys fs,
686 struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
688 static blk_t last_blk = 0;
699 retval = ext2fs_new_block(fs, last_blk, ctx->block_found_map,
706 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
712 retval = ext2fs_write_dir_block(fs, new_blk, block);
714 retval = ext2fs_get_mem(fs->blocksize, (void **) &block);
719 memset(block, 0, fs->blocksize);
720 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
726 ext2fs_free_mem((void **) &block);
728 ext2fs_mark_block_bitmap(ctx->block_found_map, new_blk);
729 ext2fs_mark_block_bitmap(fs->block_map, new_blk);
730 ext2fs_mark_bb_dirty(fs);
734 return (BLOCK_CHANGED | BLOCK_ABORT);
736 return BLOCK_CHANGED;
739 static errcode_t expand_directory(e2fsck_t ctx, ino_t dir)
741 ext2_filsys fs = ctx->fs;
743 struct expand_dir_struct es;
744 struct ext2_inode inode;
746 if (!(fs->flags & EXT2_FLAG_RW))
747 return EXT2_ET_RO_FILSYS;
750 * Read the inode and block bitmaps in; we'll be messing with
753 e2fsck_read_bitmaps(ctx);
755 retval = ext2fs_check_directory(fs, dir);
764 retval = ext2fs_block_iterate(fs, dir, BLOCK_FLAG_APPEND,
765 0, expand_dir_proc, &es);
770 return EXT2_ET_EXPAND_DIR_ERR;
773 * Update the size and block count fields in the inode.
775 retval = ext2fs_read_inode(fs, dir, &inode);
779 inode.i_size += fs->blocksize;
780 inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
782 e2fsck_write_inode(ctx, dir, &inode, "expand_directory");