Function fat_remove_used_space

src/fatp.c:206–244

}

unsigned int fat_remove_used_space(disk_t *disk_car, const partition_t *partition, alloc_data_t *list_search_space)
{
    unsigned long int fat_length;
    unsigned long int start_fat1;
    unsigned long int part_size;
    unsigned int no_of_cluster;
    unsigned int start_data;
    unsigned char *buffer;
    unsigned int res;
    unsigned int sector_size;
    const struct fat_boot_sector *fat_header;
    buffer=(unsigned char *)MALLOC(3*disk_car->sector_size);
    fat_header=(const struct fat_boot_sector *)buffer;
    if((unsigned)disk_car->pread(disk_car, buffer, 3 * disk_car->sector_size, partition->part_offset) != 3 * disk_car->sector_size)
    {
      free(buffer);
      return 0;
    }
    sector_size=fat_sector_size(fat_header);
    if(sector_size==0)
    {
      free(buffer);
      return 0;
    }
    fat_length=le16(fat_header->fat_length)>0?le16(fat_header->fat_length):le32(fat_header->fat32_length);
    part_size=(fat_sectors(fat_header)>0?fat_sectors(fat_header):le32(fat_header->total_sect));
    start_fat1=le16(fat_header->reserved);
    start_data=start_fat1+fat_header->fats*fat_length+(get_dir_entries(fat_header)*32+sector_size-1)/sector_size;
    no_of_cluster=(part_size-start_data)/fat_header->sectors_per_cluster;
    if(partition->upart_type==UP_FAT12)
      fat12_remove_used_space(disk_car,partition, list_search_space, start_fat1, no_of_cluster, start_data, fat_header->sectors_per_cluster,sector_size);
    else if(partition->upart_type==UP_FAT16)
      fat16_remove_used_space(disk_car,partition, list_search_space, start_fat1, no_of_cluster, start_data, fat_header->sectors_per_cluster,sector_size);
    else if(partition->upart_type==UP_FAT32)
      fat32_remove_used_space(disk_car,partition, list_search_space, start_fat1, no_of_cluster, start_data, fat_header->sectors_per_cluster,sector_size);
    res=fat_header->sectors_per_cluster * sector_size;
    free(buffer);
    return res;
}