2 * pass3.c -- pass #3 of e2fsck: Check for directory connectivity
4 * Copyright (C) 1993, 1994, 1995, 1996, 1997 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 void 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 max, 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,
86 "inode loop detection bitmap", &inode_loop_detect);
89 fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx);
90 ctx->flags |= E2F_FLAG_ABORT;
93 pctx.errcode = ext2fs_allocate_inode_bitmap(fs, "inode done bitmap",
97 fix_problem(ctx, PR_3_ALLOCATE_IBITMAP_ERROR, &pctx);
98 ctx->flags |= E2F_FLAG_ABORT;
101 #ifdef RESOURCE_TRACK
102 if (ctx->options & E2F_OPT_TIME)
103 print_resource_track("Peak memory", &ctx->global_rtrack);
107 if (ctx->flags & E2F_FLAG_SIGNAL_MASK)
110 ext2fs_mark_inode_bitmap(inode_done_map, EXT2_ROOT_INO);
112 max = e2fsck_get_num_dirinfo(ctx);
115 for (i=0; (dir = e2fsck_dir_info_iter(ctx, &i)) != 0;) {
117 if ((ctx->progress)(ctx, 3, count++, max))
119 if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, dir->ino))
120 check_directory(ctx, dir, &pctx);
123 if ((ctx->progress)(ctx, 3, max, max))
127 e2fsck_free_dir_info(ctx);
128 if (inode_loop_detect)
129 ext2fs_free_inode_bitmap(inode_loop_detect);
131 ext2fs_free_inode_bitmap(inode_done_map);
132 #ifdef RESOURCE_TRACK
133 if (ctx->options & E2F_OPT_TIME2)
134 print_resource_track("Pass 3", &rtrack);
139 * This makes sure the root inode is present; if not, we ask if the
140 * user wants us to create it. Not creating it is a fatal error.
142 static void check_root(e2fsck_t ctx)
144 ext2_filsys fs = ctx->fs;
146 struct ext2_inode inode;
148 struct problem_context pctx;
150 clear_problem_context(&pctx);
152 if (ext2fs_test_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO)) {
154 * If the root inode is not a directory, die here. The
155 * user must have answered 'no' in pass1 when we
156 * offered to clear it.
158 if (!(ext2fs_test_inode_bitmap(ctx->inode_dir_map,
160 fix_problem(ctx, PR_3_ROOT_NOT_DIR_ABORT, &pctx);
161 ctx->flags |= E2F_FLAG_ABORT;
166 if (!fix_problem(ctx, PR_3_NO_ROOT_INODE, &pctx)) {
167 fix_problem(ctx, PR_3_NO_ROOT_INODE_ABORT, &pctx);
168 ctx->flags |= E2F_FLAG_ABORT;
172 e2fsck_read_bitmaps(ctx);
175 * First, find a free block
177 pctx.errcode = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
179 pctx.str = "ext2fs_new_block";
180 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
181 ctx->flags |= E2F_FLAG_ABORT;
184 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
185 ext2fs_mark_block_bitmap(fs->block_map, blk);
186 ext2fs_mark_bb_dirty(fs);
189 * Now let's create the actual data block for the inode
191 pctx.errcode = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO,
194 pctx.str = "ext2fs_new_dir_block";
195 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
196 ctx->flags |= E2F_FLAG_ABORT;
200 pctx.errcode = ext2fs_write_dir_block(fs, blk, block);
202 pctx.str = "ext2fs_write_dir_block";
203 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
204 ctx->flags |= E2F_FLAG_ABORT;
207 ext2fs_free_mem((void **) &block);
210 * Set up the inode structure
212 memset(&inode, 0, sizeof(inode));
213 inode.i_mode = 040755;
214 inode.i_size = fs->blocksize;
215 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
216 inode.i_links_count = 2;
217 inode.i_blocks = fs->blocksize / 512;
218 inode.i_block[0] = blk;
221 * Write out the inode.
223 pctx.errcode = ext2fs_write_inode(fs, EXT2_ROOT_INO, &inode);
225 pctx.str = "ext2fs_write_inode";
226 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
227 ctx->flags |= E2F_FLAG_ABORT;
232 * Miscellaneous bookkeeping...
234 e2fsck_add_dir_info(ctx, EXT2_ROOT_INO, EXT2_ROOT_INO);
235 ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2);
236 ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2);
238 ext2fs_mark_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO);
239 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, EXT2_ROOT_INO);
240 ext2fs_mark_inode_bitmap(fs->inode_map, EXT2_ROOT_INO);
241 ext2fs_mark_ib_dirty(fs);
245 * This subroutine is responsible for making sure that a particular
246 * directory is connected to the root; if it isn't we trace it up as
247 * far as we can go, and then offer to connect the resulting parent to
248 * the lost+found. We have to do loop detection; if we ever discover
249 * a loop, we treat that as a disconnected directory and offer to
250 * reparent it to lost+found.
252 static void check_directory(e2fsck_t ctx, struct dir_info *dir,
253 struct problem_context *pctx)
255 ext2_filsys fs = ctx->fs;
256 struct dir_info *p = dir;
258 ext2fs_clear_inode_bitmap(inode_loop_detect);
261 * If we find a parent which we've already checked,
262 * then stop; we know it's either already connected to
263 * the directory tree, or it isn't but the user has
264 * already told us he doesn't want us to reconnect the
265 * disconnected subtree.
267 if (ext2fs_test_inode_bitmap(inode_done_map, p->ino))
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 ext2fs_mark_inode_bitmap(inode_done_map, p->ino);
278 * If this directory doesn't have a parent, or we've
279 * seen the parent once already, then offer to
280 * reparent it to lost+found
283 (ext2fs_test_inode_bitmap(inode_loop_detect,
286 ext2fs_mark_inode_bitmap(inode_loop_detect,
288 p = e2fsck_get_dir_info(ctx, p->parent);
291 * If we've reached here, we've hit a detached directory
292 * inode; offer to reconnect it to lost+found.
295 if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) {
296 if (e2fsck_reconnect_file(ctx, p->ino))
297 ext2fs_unmark_valid(fs);
299 p->parent = lost_and_found;
300 fix_dotdot(ctx, p, lost_and_found);
305 * Make sure that .. and the parent directory are the same;
306 * offer to fix it if not.
309 if (dir->parent != dir->dotdot) {
310 pctx->ino = dir->ino;
311 pctx->ino2 = dir->dotdot;
312 pctx->dir = dir->parent;
313 if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx))
314 fix_dotdot(ctx, dir, dir->parent);
319 * This routine gets the lost_and_found inode, making it a directory
322 ino_t get_lost_and_found(e2fsck_t ctx)
324 ext2_filsys fs = ctx->fs;
328 struct ext2_inode inode;
330 const char name[] = "lost+found";
331 struct problem_context pctx;
333 clear_problem_context(&pctx);
335 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
336 sizeof(name)-1, 0, &ino);
339 if (retval != EXT2_ET_FILE_NOT_FOUND) {
340 pctx.errcode = retval;
341 fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx);
343 if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0))
347 * Read the inode and block bitmaps in; we'll be messing with
350 e2fsck_read_bitmaps(ctx);
353 * First, find a free block
355 retval = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
357 pctx.errcode = retval;
358 fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx);
361 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
362 ext2fs_mark_block_bitmap(fs->block_map, blk);
363 ext2fs_mark_bb_dirty(fs);
366 * Next find a free inode.
368 retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040755,
369 ctx->inode_used_map, &ino);
371 pctx.errcode = retval;
372 fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx);
375 ext2fs_mark_inode_bitmap(ctx->inode_used_map, ino);
376 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, ino);
377 ext2fs_mark_inode_bitmap(fs->inode_map, ino);
378 ext2fs_mark_ib_dirty(fs);
381 * Now let's create the actual data block for the inode
383 retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block);
385 pctx.errcode = retval;
386 fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx);
390 retval = ext2fs_write_dir_block(fs, blk, block);
391 ext2fs_free_mem((void **) &block);
393 pctx.errcode = retval;
394 fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx);
399 * Set up the inode structure
401 memset(&inode, 0, sizeof(inode));
402 inode.i_mode = 040755;
403 inode.i_size = fs->blocksize;
404 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
405 inode.i_links_count = 2;
406 inode.i_blocks = fs->blocksize / 512;
407 inode.i_block[0] = blk;
410 * Next, write out the inode.
412 pctx.errcode = ext2fs_write_inode(fs, ino, &inode);
414 pctx.str = "ext2fs_write_inode";
415 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
419 * Finally, create the directory link
421 pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, 0);
423 pctx.str = "ext2fs_link";
424 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
429 * Miscellaneous bookkeeping that needs to be kept straight.
431 e2fsck_add_dir_info(ctx, ino, EXT2_ROOT_INO);
432 adjust_inode_count(ctx, EXT2_ROOT_INO, +1);
433 ext2fs_icount_store(ctx->inode_count, ino, 2);
434 ext2fs_icount_store(ctx->inode_link_info, ino, 2);
436 printf("/lost+found created; inode #%lu\n", ino);
442 * This routine will connect a file to lost+found
444 int e2fsck_reconnect_file(e2fsck_t ctx, ino_t inode)
446 ext2_filsys fs = ctx->fs;
449 struct problem_context pctx;
451 clear_problem_context(&pctx);
454 if (!bad_lost_and_found && !lost_and_found) {
455 lost_and_found = get_lost_and_found(ctx);
457 bad_lost_and_found++;
459 if (bad_lost_and_found) {
460 fix_problem(ctx, PR_3_NO_LPF, &pctx);
464 sprintf(name, "#%lu", inode);
465 retval = ext2fs_link(fs, lost_and_found, name, inode, 0);
466 if (retval == EXT2_ET_DIR_NO_SPACE) {
467 if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx))
469 retval = expand_directory(ctx, lost_and_found);
471 pctx.errcode = retval;
472 fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx);
475 retval = ext2fs_link(fs, lost_and_found, name, inode, 0);
478 pctx.errcode = retval;
479 fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx);
482 adjust_inode_count(ctx, inode, +1);
488 * Utility routine to adjust the inode counts on an inode.
490 static errcode_t adjust_inode_count(e2fsck_t ctx, ino_t ino, int adj)
492 ext2_filsys fs = ctx->fs;
494 struct ext2_inode inode;
499 retval = ext2fs_read_inode(fs, ino, &inode);
504 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
505 inode.i_links_count);
508 inode.i_links_count += adj;
510 ext2fs_icount_increment(ctx->inode_count, ino, 0);
511 ext2fs_icount_increment(ctx->inode_link_info, ino, 0);
513 ext2fs_icount_decrement(ctx->inode_count, ino, 0);
514 ext2fs_icount_decrement(ctx->inode_link_info, ino, 0);
518 retval = ext2fs_write_inode(fs, ino, &inode);
526 * Fix parent --- this routine fixes up the parent of a directory.
528 struct fix_dotdot_struct {
535 static int fix_dotdot_proc(struct ext2_dir_entry *dirent,
541 struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) priv_data;
543 struct problem_context pctx;
545 if ((dirent->name_len & 0xFF) != 2)
547 if (strncmp(dirent->name, "..", 2))
550 clear_problem_context(&pctx);
552 retval = adjust_inode_count(fp->ctx, dirent->inode, -1);
554 pctx.errcode = retval;
555 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
557 retval = adjust_inode_count(fp->ctx, fp->parent, 1);
559 pctx.errcode = retval;
560 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
562 dirent->inode = fp->parent;
565 return DIRENT_ABORT | DIRENT_CHANGED;
568 static void fix_dotdot(e2fsck_t ctx, struct dir_info *dir, ino_t parent)
570 ext2_filsys fs = ctx->fs;
572 struct fix_dotdot_struct fp;
573 struct problem_context pctx;
581 printf("Fixing '..' of inode %lu to be %lu...\n", dir->ino, parent);
584 retval = ext2fs_dir_iterate(fs, dir->ino, DIRENT_FLAG_INCLUDE_EMPTY,
585 0, fix_dotdot_proc, &fp);
586 if (retval || !fp.done) {
587 clear_problem_context(&pctx);
589 pctx.errcode = retval;
590 fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR :
591 PR_3_FIX_PARENT_NOFIND, &pctx);
592 ext2fs_unmark_valid(fs);
594 dir->dotdot = parent;
600 * These routines are responsible for expanding a /lost+found if it is
604 struct expand_dir_struct {
610 static int expand_dir_proc(ext2_filsys fs,
615 struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
617 static blk_t last_blk = 0;
628 retval = ext2fs_new_block(fs, last_blk, ctx->block_found_map,
635 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
641 retval = ext2fs_write_dir_block(fs, new_blk, block);
643 retval = ext2fs_get_mem(fs->blocksize, (void **) &block);
648 memset(block, 0, fs->blocksize);
649 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
655 ext2fs_free_mem((void **) &block);
657 ext2fs_mark_block_bitmap(ctx->block_found_map, new_blk);
658 ext2fs_mark_block_bitmap(fs->block_map, new_blk);
659 ext2fs_mark_bb_dirty(fs);
661 return (BLOCK_CHANGED | BLOCK_ABORT);
663 return BLOCK_CHANGED;
666 static errcode_t expand_directory(e2fsck_t ctx, ino_t dir)
668 ext2_filsys fs = ctx->fs;
670 struct expand_dir_struct es;
671 struct ext2_inode inode;
673 if (!(fs->flags & EXT2_FLAG_RW))
674 return EXT2_ET_RO_FILSYS;
677 * Read the inode and block bitmaps in; we'll be messing with
680 e2fsck_read_bitmaps(ctx);
682 retval = ext2fs_check_directory(fs, dir);
690 retval = ext2fs_block_iterate(fs, dir, BLOCK_FLAG_APPEND,
691 0, expand_dir_proc, &es);
696 return EXT2_ET_EXPAND_DIR_ERR;
699 * Update the size and block count fields in the inode.
701 retval = ext2fs_read_inode(fs, dir, &inode);
705 inode.i_size += fs->blocksize;
706 inode.i_blocks += fs->blocksize / 512;
708 e2fsck_write_inode(ctx, dir, &inode, "expand_directory");