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;
56 static ext2fs_inode_bitmap inode_done_map;
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_ABORT)
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 (ctx->progress)(ctx, 3, count++, max);
118 if (ext2fs_test_inode_bitmap(ctx->inode_dir_map, dir->ino))
119 check_directory(ctx, dir, &pctx);
122 (ctx->progress)(ctx, 3, max, max);
124 e2fsck_free_dir_info(ctx);
125 ext2fs_free_inode_bitmap(inode_loop_detect);
126 ext2fs_free_inode_bitmap(inode_done_map);
127 #ifdef RESOURCE_TRACK
128 if (ctx->options & E2F_OPT_TIME2)
129 print_resource_track("Pass 3", &rtrack);
134 * This makes sure the root inode is present; if not, we ask if the
135 * user wants us to create it. Not creating it is a fatal error.
137 static void check_root(e2fsck_t ctx)
139 ext2_filsys fs = ctx->fs;
141 struct ext2_inode inode;
143 struct problem_context pctx;
145 clear_problem_context(&pctx);
147 if (ext2fs_test_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO)) {
149 * If the root inode is not a directory, die here. The
150 * user must have answered 'no' in pass1 when we
151 * offered to clear it.
153 if (!(ext2fs_test_inode_bitmap(ctx->inode_dir_map,
155 fix_problem(ctx, PR_3_ROOT_NOT_DIR_ABORT, &pctx);
156 ctx->flags |= E2F_FLAG_ABORT;
161 if (!fix_problem(ctx, PR_3_NO_ROOT_INODE, &pctx)) {
162 fix_problem(ctx, PR_3_NO_ROOT_INODE_ABORT, &pctx);
163 ctx->flags |= E2F_FLAG_ABORT;
167 e2fsck_read_bitmaps(ctx);
170 * First, find a free block
172 pctx.errcode = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
174 pctx.str = "ext2fs_new_block";
175 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
176 ctx->flags |= E2F_FLAG_ABORT;
179 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
180 ext2fs_mark_block_bitmap(fs->block_map, blk);
181 ext2fs_mark_bb_dirty(fs);
184 * Now let's create the actual data block for the inode
186 pctx.errcode = ext2fs_new_dir_block(fs, EXT2_ROOT_INO, EXT2_ROOT_INO,
189 pctx.str = "ext2fs_new_dir_block";
190 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
191 ctx->flags |= E2F_FLAG_ABORT;
195 pctx.errcode = ext2fs_write_dir_block(fs, blk, block);
197 pctx.str = "ext2fs_write_dir_block";
198 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
199 ctx->flags |= E2F_FLAG_ABORT;
202 ext2fs_free_mem((void **) &block);
205 * Set up the inode structure
207 memset(&inode, 0, sizeof(inode));
208 inode.i_mode = 040755;
209 inode.i_size = fs->blocksize;
210 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
211 inode.i_links_count = 2;
212 inode.i_blocks = fs->blocksize / 512;
213 inode.i_block[0] = blk;
216 * Write out the inode.
218 pctx.errcode = ext2fs_write_inode(fs, EXT2_ROOT_INO, &inode);
220 pctx.str = "ext2fs_write_inode";
221 fix_problem(ctx, PR_3_CREATE_ROOT_ERROR, &pctx);
222 ctx->flags |= E2F_FLAG_ABORT;
227 * Miscellaneous bookkeeping...
229 e2fsck_add_dir_info(ctx, EXT2_ROOT_INO, EXT2_ROOT_INO);
230 ext2fs_icount_store(ctx->inode_count, EXT2_ROOT_INO, 2);
231 ext2fs_icount_store(ctx->inode_link_info, EXT2_ROOT_INO, 2);
233 ext2fs_mark_inode_bitmap(ctx->inode_used_map, EXT2_ROOT_INO);
234 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, EXT2_ROOT_INO);
235 ext2fs_mark_inode_bitmap(fs->inode_map, EXT2_ROOT_INO);
236 ext2fs_mark_ib_dirty(fs);
240 * This subroutine is responsible for making sure that a particular
241 * directory is connected to the root; if it isn't we trace it up as
242 * far as we can go, and then offer to connect the resulting parent to
243 * the lost+found. We have to do loop detection; if we ever discover
244 * a loop, we treat that as a disconnected directory and offer to
245 * reparent it to lost+found.
247 static void check_directory(e2fsck_t ctx, struct dir_info *dir,
248 struct problem_context *pctx)
250 ext2_filsys fs = ctx->fs;
251 struct dir_info *p = dir;
253 ext2fs_clear_inode_bitmap(inode_loop_detect);
256 * If we find a parent which we've already checked,
257 * then stop; we know it's either already connected to
258 * the directory tree, or it isn't but the user has
259 * already told us he doesn't want us to reconnect the
260 * disconnected subtree.
262 if (ext2fs_test_inode_bitmap(inode_done_map, p->ino))
265 * Mark this inode as being "done"; by the time we
266 * return from this function, the inode we either be
267 * verified as being connected to the directory tree,
268 * or we will have offered to reconnect this to
271 ext2fs_mark_inode_bitmap(inode_done_map, p->ino);
273 * If this directory doesn't have a parent, or we've
274 * seen the parent once already, then offer to
275 * reparent it to lost+found
278 (ext2fs_test_inode_bitmap(inode_loop_detect,
281 ext2fs_mark_inode_bitmap(inode_loop_detect,
283 p = e2fsck_get_dir_info(ctx, p->parent);
286 * If we've reached here, we've hit a detached directory
287 * inode; offer to reconnect it to lost+found.
290 if (fix_problem(ctx, PR_3_UNCONNECTED_DIR, pctx)) {
291 if (e2fsck_reconnect_file(ctx, p->ino))
292 ext2fs_unmark_valid(fs);
294 p->parent = lost_and_found;
295 fix_dotdot(ctx, p, lost_and_found);
300 * Make sure that .. and the parent directory are the same;
301 * offer to fix it if not.
304 if (dir->parent != dir->dotdot) {
305 pctx->ino = dir->ino;
306 pctx->ino2 = dir->dotdot;
307 pctx->dir = dir->parent;
308 if (fix_problem(ctx, PR_3_BAD_DOT_DOT, pctx))
309 fix_dotdot(ctx, dir, dir->parent);
314 * This routine gets the lost_and_found inode, making it a directory
317 ino_t get_lost_and_found(e2fsck_t ctx)
319 ext2_filsys fs = ctx->fs;
323 struct ext2_inode inode;
325 const char name[] = "lost+found";
326 struct problem_context pctx;
328 clear_problem_context(&pctx);
330 retval = ext2fs_lookup(fs, EXT2_ROOT_INO, name,
331 sizeof(name)-1, 0, &ino);
334 if (retval != EXT2_ET_FILE_NOT_FOUND) {
335 pctx.errcode = retval;
336 fix_problem(ctx, PR_3_ERR_FIND_LPF, &pctx);
338 if (!fix_problem(ctx, PR_3_NO_LF_DIR, 0))
342 * Read the inode and block bitmaps in; we'll be messing with
345 e2fsck_read_bitmaps(ctx);
348 * First, find a free block
350 retval = ext2fs_new_block(fs, 0, ctx->block_found_map, &blk);
352 pctx.errcode = retval;
353 fix_problem(ctx, PR_3_ERR_LPF_NEW_BLOCK, &pctx);
356 ext2fs_mark_block_bitmap(ctx->block_found_map, blk);
357 ext2fs_mark_block_bitmap(fs->block_map, blk);
358 ext2fs_mark_bb_dirty(fs);
361 * Next find a free inode.
363 retval = ext2fs_new_inode(fs, EXT2_ROOT_INO, 040755,
364 ctx->inode_used_map, &ino);
366 pctx.errcode = retval;
367 fix_problem(ctx, PR_3_ERR_LPF_NEW_INODE, &pctx);
370 ext2fs_mark_inode_bitmap(ctx->inode_used_map, ino);
371 ext2fs_mark_inode_bitmap(ctx->inode_dir_map, ino);
372 ext2fs_mark_inode_bitmap(fs->inode_map, ino);
373 ext2fs_mark_ib_dirty(fs);
376 * Now let's create the actual data block for the inode
378 retval = ext2fs_new_dir_block(fs, ino, EXT2_ROOT_INO, &block);
380 pctx.errcode = retval;
381 fix_problem(ctx, PR_3_ERR_LPF_NEW_DIR_BLOCK, &pctx);
385 retval = ext2fs_write_dir_block(fs, blk, block);
386 ext2fs_free_mem((void **) &block);
388 pctx.errcode = retval;
389 fix_problem(ctx, PR_3_ERR_LPF_WRITE_BLOCK, &pctx);
394 * Set up the inode structure
396 memset(&inode, 0, sizeof(inode));
397 inode.i_mode = 040755;
398 inode.i_size = fs->blocksize;
399 inode.i_atime = inode.i_ctime = inode.i_mtime = time(0);
400 inode.i_links_count = 2;
401 inode.i_blocks = fs->blocksize / 512;
402 inode.i_block[0] = blk;
405 * Next, write out the inode.
407 pctx.errcode = ext2fs_write_inode(fs, ino, &inode);
409 pctx.str = "ext2fs_write_inode";
410 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
414 * Finally, create the directory link
416 pctx.errcode = ext2fs_link(fs, EXT2_ROOT_INO, name, ino, 0);
418 pctx.str = "ext2fs_link";
419 fix_problem(ctx, PR_3_CREATE_LPF_ERROR, &pctx);
424 * Miscellaneous bookkeeping that needs to be kept straight.
426 e2fsck_add_dir_info(ctx, ino, EXT2_ROOT_INO);
427 adjust_inode_count(ctx, EXT2_ROOT_INO, +1);
428 ext2fs_icount_store(ctx->inode_count, ino, 2);
429 ext2fs_icount_store(ctx->inode_link_info, ino, 2);
431 printf("/lost+found created; inode #%lu\n", ino);
437 * This routine will connect a file to lost+found
439 int e2fsck_reconnect_file(e2fsck_t ctx, ino_t inode)
441 ext2_filsys fs = ctx->fs;
444 struct problem_context pctx;
446 clear_problem_context(&pctx);
449 if (!bad_lost_and_found && !lost_and_found) {
450 lost_and_found = get_lost_and_found(ctx);
452 bad_lost_and_found++;
454 if (bad_lost_and_found) {
455 fix_problem(ctx, PR_3_NO_LPF, &pctx);
459 sprintf(name, "#%lu", inode);
460 retval = ext2fs_link(fs, lost_and_found, name, inode, 0);
461 if (retval == EXT2_ET_DIR_NO_SPACE) {
462 if (!fix_problem(ctx, PR_3_EXPAND_LF_DIR, &pctx))
464 retval = expand_directory(ctx, lost_and_found);
466 pctx.errcode = retval;
467 fix_problem(ctx, PR_3_CANT_EXPAND_LPF, &pctx);
470 retval = ext2fs_link(fs, lost_and_found, name, inode, 0);
473 pctx.errcode = retval;
474 fix_problem(ctx, PR_3_CANT_RECONNECT, &pctx);
477 adjust_inode_count(ctx, inode, +1);
483 * Utility routine to adjust the inode counts on an inode.
485 static errcode_t adjust_inode_count(e2fsck_t ctx, ino_t ino, int adj)
487 ext2_filsys fs = ctx->fs;
489 struct ext2_inode inode;
494 retval = ext2fs_read_inode(fs, ino, &inode);
499 printf("Adjusting link count for inode %lu by %d (from %d)\n", ino, adj,
500 inode.i_links_count);
503 inode.i_links_count += adj;
505 ext2fs_icount_increment(ctx->inode_count, ino, 0);
506 ext2fs_icount_increment(ctx->inode_link_info, ino, 0);
508 ext2fs_icount_decrement(ctx->inode_count, ino, 0);
509 ext2fs_icount_decrement(ctx->inode_link_info, ino, 0);
513 retval = ext2fs_write_inode(fs, ino, &inode);
521 * Fix parent --- this routine fixes up the parent of a directory.
523 struct fix_dotdot_struct {
530 static int fix_dotdot_proc(struct ext2_dir_entry *dirent,
536 struct fix_dotdot_struct *fp = (struct fix_dotdot_struct *) priv_data;
538 struct problem_context pctx;
540 if (dirent->name_len != 2)
542 if (strncmp(dirent->name, "..", 2))
545 clear_problem_context(&pctx);
547 retval = adjust_inode_count(fp->ctx, dirent->inode, -1);
549 pctx.errcode = retval;
550 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
552 retval = adjust_inode_count(fp->ctx, fp->parent, 1);
554 pctx.errcode = retval;
555 fix_problem(fp->ctx, PR_3_ADJUST_INODE, &pctx);
557 dirent->inode = fp->parent;
560 return DIRENT_ABORT | DIRENT_CHANGED;
563 static void fix_dotdot(e2fsck_t ctx, struct dir_info *dir, ino_t parent)
565 ext2_filsys fs = ctx->fs;
567 struct fix_dotdot_struct fp;
568 struct problem_context pctx;
576 printf("Fixing '..' of inode %lu to be %lu...\n", dir->ino, parent);
579 retval = ext2fs_dir_iterate(fs, dir->ino, DIRENT_FLAG_INCLUDE_EMPTY,
580 0, fix_dotdot_proc, &fp);
581 if (retval || !fp.done) {
582 clear_problem_context(&pctx);
584 pctx.errcode = retval;
585 fix_problem(ctx, retval ? PR_3_FIX_PARENT_ERR :
586 PR_3_FIX_PARENT_NOFIND, &pctx);
587 ext2fs_unmark_valid(fs);
589 dir->dotdot = parent;
595 * These routines are responsible for expanding a /lost+found if it is
599 struct expand_dir_struct {
605 static int expand_dir_proc(ext2_filsys fs,
610 struct expand_dir_struct *es = (struct expand_dir_struct *) priv_data;
612 static blk_t last_blk = 0;
623 retval = ext2fs_new_block(fs, last_blk, ctx->block_found_map,
630 retval = ext2fs_new_dir_block(fs, 0, 0, &block);
636 retval = ext2fs_write_dir_block(fs, new_blk, block);
638 retval = ext2fs_get_mem(fs->blocksize, (void **) &block);
643 memset(block, 0, fs->blocksize);
644 retval = io_channel_write_blk(fs->io, new_blk, 1, block);
650 ext2fs_free_mem((void **) &block);
652 ext2fs_mark_block_bitmap(ctx->block_found_map, new_blk);
653 ext2fs_mark_block_bitmap(fs->block_map, new_blk);
654 ext2fs_mark_bb_dirty(fs);
656 return (BLOCK_CHANGED | BLOCK_ABORT);
658 return BLOCK_CHANGED;
661 static errcode_t expand_directory(e2fsck_t ctx, ino_t dir)
663 ext2_filsys fs = ctx->fs;
665 struct expand_dir_struct es;
666 struct ext2_inode inode;
668 if (!(fs->flags & EXT2_FLAG_RW))
669 return EXT2_ET_RO_FILSYS;
672 * Read the inode and block bitmaps in; we'll be messing with
675 e2fsck_read_bitmaps(ctx);
677 retval = ext2fs_check_directory(fs, dir);
685 retval = ext2fs_block_iterate(fs, dir, BLOCK_FLAG_APPEND,
686 0, expand_dir_proc, &es);
691 return EXT2_ET_EXPAND_DIR_ERR;
694 * Update the size and block count fields in the inode.
696 retval = ext2fs_read_inode(fs, dir, &inode);
700 inode.i_size += fs->blocksize;
701 inode.i_blocks += fs->blocksize / 512;
703 e2fsck_write_inode(ctx, dir, &inode, "expand_directory");