source: MondoRescue/branches/stable/mindi-busybox/e2fsprogs/ext2fs/bitmaps.c@ 821

/*
 * 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);

    return;
}

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));
}