alloc_sb.c revision ef344e13d2125e9dae3764b98f9fe3a170cd79e2 
1/*
2 * alloc_sb.c --- Allocate the superblock and block group descriptors for a
3 * newly initialized filesystem.  Used by mke2fs when initializing a filesystem
4 *
5 * Copyright (C) 1994, 1995, 1996, 2003 Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Public
9 * License.
10 * %End-Header%
11 */
12
13#include <stdio.h>
14#include <string.h>
15#if HAVE_UNISTD_H
16#include <unistd.h>
17#endif
18#include <fcntl.h>
19#include <time.h>
20#if HAVE_SYS_STAT_H
21#include <sys/stat.h>
22#endif
23#if HAVE_SYS_TYPES_H
24#include <sys/types.h>
25#endif
26
27#include "ext2_fs.h"
28#include "ext2fs.h"
29
30int ext2fs_reserve_super_and_bgd(ext2_filsys fs,
31				 dgrp_t group,
32				 ext2fs_block_bitmap bmap)
33{
34	blk_t	super_blk, old_desc_blk, new_desc_blk;
35	int	j, old_desc_blocks, num_blocks;
36
37	num_blocks = ext2fs_super_and_bgd_loc(fs, group, &super_blk,
38					      &old_desc_blk, &new_desc_blk, 0);
39
40	if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
41		old_desc_blocks = fs->super->s_first_meta_bg;
42	else
43		old_desc_blocks = fs->desc_blocks;
44
45	if (super_blk || (group == 0))
46		ext2fs_mark_block_bitmap(bmap, super_blk);
47
48	if (old_desc_blk) {
49		for (j=0; j < old_desc_blocks; j++)
50			ext2fs_mark_block_bitmap(bmap, old_desc_blk + j);
51	}
52	if (new_desc_blk)
53		ext2fs_mark_block_bitmap(bmap, new_desc_blk);
54
55	return num_blocks;
56}
57