alloc_tables.c revision 9f8046fc6dfc13eee2f5c363214e60b533872cac 
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	start_blk = group_blk + 3 + fs->desc_blocks;
45	if (start_blk > last_blk)
46		start_blk = group_blk;
47
48	if (!bmap)
49		bmap = fs->block_map;
50
51	/*
52	 * Allocate the inode table
53	 */
54	if (!fs->group_desc[group].bg_inode_table) {
55		retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
56						fs->inode_blocks_per_group,
57						bmap, &new_blk);
58		if (retval)
59			return retval;
60		for (j=0, blk = new_blk;
61		     j < fs->inode_blocks_per_group;
62		     j++, blk++)
63			ext2fs_mark_block_bitmap(bmap, blk);
64		fs->group_desc[group].bg_inode_table = new_blk;
65	}
66
67	/*
68	 * Allocate the block and inode bitmaps, if necessary
69	 */
70	if (fs->stride) {
71		start_blk += fs->inode_blocks_per_group;
72		start_blk += ((fs->stride * group) %
73			      (last_blk - start_blk));
74		if (start_blk > last_blk)
75			/* should never happen */
76			start_blk = group_blk;
77	} else
78		start_blk = group_blk;
79
80	if (!fs->group_desc[group].bg_block_bitmap) {
81		retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
82						1, bmap, &new_blk);
83		if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
84			retval = ext2fs_get_free_blocks(fs, group_blk,
85					last_blk, 1, bmap, &new_blk);
86		if (retval)
87			return retval;
88		ext2fs_mark_block_bitmap(bmap, new_blk);
89		fs->group_desc[group].bg_block_bitmap = new_blk;
90	}
91
92	if (!fs->group_desc[group].bg_inode_bitmap) {
93		retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
94						1, bmap, &new_blk);
95		if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
96			retval = ext2fs_get_free_blocks(fs, group_blk,
97					last_blk, 1, bmap, &new_blk);
98		if (retval)
99			return retval;
100		ext2fs_mark_block_bitmap(bmap, new_blk);
101		fs->group_desc[group].bg_inode_bitmap = new_blk;
102	}
103	return 0;
104}
105
106
107
108errcode_t ext2fs_allocate_tables(ext2_filsys fs)
109{
110	errcode_t	retval;
111	dgrp_t		i;
112
113	for (i = 0; i < fs->group_desc_count; i++) {
114		retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
115		if (retval)
116			return retval;
117	}
118	return 0;
119}
120
121