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/*
* alloc.c --- allocate new inodes, blocks for ext2fs
*
* Copyright (C) 1993 Theodore Ts'o. This file may be redistributed
* under the terms of the GNU Public License.
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/types.h>
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#include <linux/ext2_fs.h>
#include "ext2fs.h"
/*
* Right now, just search forward from the parent directory's block
* group to find the next free inode.
*
* Should have a special policy for directories.
*/
errcode_t ext2fs_new_inode(ext2_filsys fs, ino_t dir, int mode,
ext2fs_inode_bitmap map, ino_t *ret)
{
int dir_group = 0;
ino_t i;
ino_t start_inode;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->inode_map;
if (!map)
return EXT2_ET_NO_INODE_BITMAP;
if (dir > 0)
dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
if (start_inode < EXT2_FIRST_INO)
start_inode = EXT2_FIRST_INO;
i = start_inode;
do {
if (!ext2fs_test_inode_bitmap(map, i))
break;
i++;
if (i > fs->super->s_inodes_count)
i = EXT2_FIRST_INO;
} while (i != start_inode);
if (ext2fs_test_inode_bitmap(map, i))
return ENOSPC;
*ret = i;
return 0;
}
/*
* Stupid algorithm --- we now just search forward starting from the
* goal. Should put in a smarter one someday....
*/
errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
ext2fs_block_bitmap map, blk_t *ret)
{
blk_t i = goal;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!i)
i = fs->super->s_first_data_block;
do {
if (!ext2fs_test_block_bitmap(map, i)) {
*ret = i;
return 0;
}
i++;
if (i > fs->super->s_blocks_count)
i = fs->super->s_first_data_block;
} while (i != goal);
return ENOSPC;
}
static int check_blocks_free(ext2_filsys fs, ext2fs_block_bitmap map,
blk_t blk, int num)
{
int i;
for (i=0; i < num; i++) {
if ((blk+i) > fs->super->s_blocks_count)
return 0;
if (ext2fs_test_block_bitmap(map, blk+i))
return 0;
}
return 1;
}
errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
int num, ext2fs_block_bitmap map, blk_t *ret)
{
blk_t b = start;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!b)
b = fs->super->s_first_data_block;
if (!finish)
finish = start;
if (!num)
num = 1;
do {
if (check_blocks_free(fs, map, b, num)) {
*ret = b;
return 0;
}
b++;
if (b > fs->super->s_blocks_count)
b = fs->super->s_first_data_block;
} while (b != finish);
return ENOSPC;
}
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