alloc_tables.c revision bc2699f018586f21825e056eb6053686c23804fe 
1/*
2 * alloc_tables.c --- Allocate tables for a newly initialized
3 * filesystem.  Used by mke2fs when initializing a filesystem
4 *
5 * Copyright (C) 1996 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
30errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
31				      ext2fs_block_bitmap bmap)
32{
33	errcode_t	retval;
34	blk_t		group_blk, start_blk, last_blk, new_blk, blk;
35	int		j;
36
37	group_blk = fs->super->s_first_data_block +
38		(group * fs->super->s_blocks_per_group);
39
40	last_blk = group_blk + fs->super->s_blocks_per_group;
41	if (last_blk >= fs->super->s_blocks_count)
42		last_blk = fs->super->s_blocks_count - 1;
43
44	if (!bmap)
45		bmap = fs->block_map;
46
47	/*
48	 * Allocate the block and inode bitmaps, if necessary
49	 */
50	if (fs->stride) {
51		retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
52						1, bmap, &start_blk);
53		if (retval)
54			return retval;
55		start_blk += fs->inode_blocks_per_group;
56		start_blk += ((fs->stride * group) %
57			      (last_blk - start_blk));
58		if (start_blk > last_blk)
59			start_blk = group_blk;
60	} else
61		start_blk = group_blk;
62
63	if (!fs->group_desc[group].bg_block_bitmap) {
64		retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
65						1, bmap, &new_blk);
66		if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
67			retval = ext2fs_get_free_blocks(fs, group_blk,
68					last_blk, 1, bmap, &new_blk);
69		if (retval)
70			return retval;
71		ext2fs_mark_block_bitmap(bmap, new_blk);
72		fs->group_desc[group].bg_block_bitmap = new_blk;
73	}
74
75	if (!fs->group_desc[group].bg_inode_bitmap) {
76		retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
77						1, bmap, &new_blk);
78		if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
79			retval = ext2fs_get_free_blocks(fs, group_blk,
80					last_blk, 1, bmap, &new_blk);
81		if (retval)
82			return retval;
83		ext2fs_mark_block_bitmap(bmap, new_blk);
84		fs->group_desc[group].bg_inode_bitmap = new_blk;
85	}
86
87	/*
88	 * Allocate the inode table
89	 */
90	if (!fs->group_desc[group].bg_inode_table) {
91		retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
92						fs->inode_blocks_per_group,
93						bmap, &new_blk);
94		if (retval)
95			return retval;
96		for (j=0, blk = new_blk;
97		     j < fs->inode_blocks_per_group;
98		     j++, blk++)
99			ext2fs_mark_block_bitmap(bmap, blk);
100		fs->group_desc[group].bg_inode_table = new_blk;
101	}
102
103
104	return 0;
105}
106
107
108
109errcode_t ext2fs_allocate_tables(ext2_filsys fs)
110{
111	errcode_t	retval;
112	dgrp_t		i;
113
114	for (i = 0; i < fs->group_desc_count; i++) {
115		retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
116		if (retval)
117			return retval;
118	}
119	return 0;
120}
121
122