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/*
* alloc.c --- allocate new inodes, blocks for ext2fs
*
* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*
*/
#include <stdio.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <time.h>
#include <string.h>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "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, ext2_ino_t dir, int mode,
ext2fs_inode_bitmap map, ext2_ino_t *ret)
{
ext2_ino_t dir_group = 0;
ext2_ino_t i;
ext2_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_INODE(fs->super))
start_inode = EXT2_FIRST_INODE(fs->super);
i = start_inode;
do {
if (!ext2fs_fast_test_inode_bitmap(map, i))
break;
i++;
if (i > fs->super->s_inodes_count)
i = EXT2_FIRST_INODE(fs->super);
} while (i != start_inode);
if (ext2fs_test_inode_bitmap(map, i))
return EXT2_ET_INODE_ALLOC_FAIL;
*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;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!map)
map = fs->block_map;
if (!map)
return EXT2_ET_NO_BLOCK_BITMAP;
if (!goal || (goal >= fs->super->s_blocks_count))
goal = fs->super->s_first_data_block;
i = goal;
do {
if (!ext2fs_fast_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 EXT2_ET_BLOCK_ALLOC_FAIL;
}
/*
* This function zeros out the allocated block, and updates all of the
* appropriate filesystem records.
*/
errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
char *block_buf, blk_t *ret)
{
errcode_t retval;
blk_t block;
int group;
char *buf = 0;
if (!block_buf) {
retval = ext2fs_get_mem(fs->blocksize, (void **) &buf);
if (retval)
return retval;
block_buf = buf;
}
memset(block_buf, 0, fs->blocksize);
if (!fs->block_map) {
retval = ext2fs_read_block_bitmap(fs);
if (retval)
goto fail;
}
retval = ext2fs_new_block(fs, goal, 0, &block);
if (retval)
goto fail;
retval = io_channel_write_blk(fs->io, block, 1, block_buf);
if (retval)
goto fail;
fs->super->s_free_blocks_count--;
group = ext2fs_group_of_blk(fs, block);
fs->group_desc[group].bg_free_blocks_count--;
ext2fs_mark_block_bitmap(fs->block_map, block);
ext2fs_mark_super_dirty(fs);
ext2fs_mark_bb_dirty(fs);
*ret = block;
return 0;
fail:
if (buf)
ext2fs_free_mem((void **) &buf);
return retval;
}
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 (b+num-1 > fs->super->s_blocks_count)
b = fs->super->s_first_data_block;
if (ext2fs_fast_test_block_bitmap_range(map, b, num)) {
*ret = b;
return 0;
}
b++;
} while (b != finish);
return EXT2_ET_BLOCK_ALLOC_FAIL;
}
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