busybox/e2fsprogs/old_e2fsprogs/ext2fs/bitmaps.c

212 lines
4.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* bitmaps.c --- routines to read, write, and manipulate the inode and
* block bitmaps.
*
* 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>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <time.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"
static errcode_t make_bitmap(__u32 start, __u32 end, __u32 real_end,
const char *descr, char *init_map,
ext2fs_generic_bitmap *ret)
{
ext2fs_generic_bitmap bitmap;
errcode_t retval;
size_t size;
retval = ext2fs_get_mem(sizeof(struct ext2fs_struct_generic_bitmap),
&bitmap);
if (retval)
return retval;
bitmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP;
bitmap->fs = NULL;
bitmap->start = start;
bitmap->end = end;
bitmap->real_end = real_end;
bitmap->base_error_code = EXT2_ET_BAD_GENERIC_MARK;
if (descr) {
retval = ext2fs_get_mem(strlen(descr)+1, &bitmap->description);
if (retval) {
ext2fs_free_mem(&bitmap);
return retval;
}
strcpy(bitmap->description, descr);
} else
bitmap->description = 0;
size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1);
retval = ext2fs_get_mem(size, &bitmap->bitmap);
if (retval) {
ext2fs_free_mem(&bitmap->description);
ext2fs_free_mem(&bitmap);
return retval;
}
if (init_map)
memcpy(bitmap->bitmap, init_map, size);
else
memset(bitmap->bitmap, 0, size);
*ret = bitmap;
return 0;
}
errcode_t ext2fs_allocate_generic_bitmap(__u32 start,
__u32 end,
__u32 real_end,
const char *descr,
ext2fs_generic_bitmap *ret)
{
return make_bitmap(start, end, real_end, descr, 0, ret);
}
errcode_t ext2fs_copy_bitmap(ext2fs_generic_bitmap src,
ext2fs_generic_bitmap *dest)
{
errcode_t retval;
ext2fs_generic_bitmap new_map;
retval = make_bitmap(src->start, src->end, src->real_end,
src->description, src->bitmap, &new_map);
if (retval)
return retval;
new_map->magic = src->magic;
new_map->fs = src->fs;
new_map->base_error_code = src->base_error_code;
*dest = new_map;
return 0;
}
void ext2fs_set_bitmap_padding(ext2fs_generic_bitmap map)
{
__u32 i, j;
for (i=map->end+1, j = i - map->start; i <= map->real_end; i++, j++)
ext2fs_set_bit(j, map->bitmap);
}
errcode_t ext2fs_allocate_inode_bitmap(ext2_filsys fs,
const char *descr,
ext2fs_inode_bitmap *ret)
{
ext2fs_inode_bitmap bitmap;
errcode_t retval;
__u32 start, end, real_end;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
fs->write_bitmaps = ext2fs_write_bitmaps;
start = 1;
end = fs->super->s_inodes_count;
real_end = (EXT2_INODES_PER_GROUP(fs->super) * fs->group_desc_count);
retval = ext2fs_allocate_generic_bitmap(start, end, real_end,
descr, &bitmap);
if (retval)
return retval;
bitmap->magic = EXT2_ET_MAGIC_INODE_BITMAP;
bitmap->fs = fs;
bitmap->base_error_code = EXT2_ET_BAD_INODE_MARK;
*ret = bitmap;
return 0;
}
errcode_t ext2fs_allocate_block_bitmap(ext2_filsys fs,
const char *descr,
ext2fs_block_bitmap *ret)
{
ext2fs_block_bitmap bitmap;
errcode_t retval;
__u32 start, end, real_end;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
fs->write_bitmaps = ext2fs_write_bitmaps;
start = fs->super->s_first_data_block;
end = fs->super->s_blocks_count-1;
real_end = (EXT2_BLOCKS_PER_GROUP(fs->super)
* fs->group_desc_count)-1 + start;
retval = ext2fs_allocate_generic_bitmap(start, end, real_end,
descr, &bitmap);
if (retval)
return retval;
bitmap->magic = EXT2_ET_MAGIC_BLOCK_BITMAP;
bitmap->fs = fs;
bitmap->base_error_code = EXT2_ET_BAD_BLOCK_MARK;
*ret = bitmap;
return 0;
}
errcode_t ext2fs_fudge_inode_bitmap_end(ext2fs_inode_bitmap bitmap,
ext2_ino_t end, ext2_ino_t *oend)
{
EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_INODE_BITMAP);
if (end > bitmap->real_end)
return EXT2_ET_FUDGE_INODE_BITMAP_END;
if (oend)
*oend = bitmap->end;
bitmap->end = end;
return 0;
}
errcode_t ext2fs_fudge_block_bitmap_end(ext2fs_block_bitmap bitmap,
blk_t end, blk_t *oend)
{
EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
if (end > bitmap->real_end)
return EXT2_ET_FUDGE_BLOCK_BITMAP_END;
if (oend)
*oend = bitmap->end;
bitmap->end = end;
return 0;
}
void ext2fs_clear_inode_bitmap(ext2fs_inode_bitmap bitmap)
{
if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_INODE_BITMAP))
return;
memset(bitmap->bitmap, 0,
(size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));
}
void ext2fs_clear_block_bitmap(ext2fs_block_bitmap bitmap)
{
if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_BLOCK_BITMAP))
return;
memset(bitmap->bitmap, 0,
(size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));
}