/* This function performs three tasks:
   - Make sectors disk relative from partition relative.
   - Normalize offset to be less than the sector size.
   - Verify that the range is inside the partition.  */
static VasEBoot_err_t
VasEBoot_disk_adjust_range (VasEBoot_disk_t disk, VasEBoot_disk_addr_t *sector,
			VasEBoot_off_t *offset, VasEBoot_size_t size)
{
  VasEBoot_partition_t part;
  VasEBoot_disk_addr_t total_sectors;

  *sector += *offset >> VAS_EBOOT_DISK_SECTOR_BITS;
  *offset &= VAS_EBOOT_DISK_SECTOR_SIZE - 1;

  for (part = disk->partition; part; part = part->parent)
    {
      VasEBoot_disk_addr_t start;
      VasEBoot_uint64_t len;

      start = part->start;
      len = part->len;

      if (*sector >= len
	  || len - *sector < ((*offset + size + VAS_EBOOT_DISK_SECTOR_SIZE - 1)
			      >> VAS_EBOOT_DISK_SECTOR_BITS))
	return VasEBoot_error (VAS_EBOOT_ERR_OUT_OF_RANGE,
			   N_("attempt to read or write outside of partition"));

      *sector += start;
    }

  /* Transform total_sectors to number of 512B blocks.  */
  total_sectors = disk->total_sectors << (disk->log_sector_size - VAS_EBOOT_DISK_SECTOR_BITS);

  /*
   * Some drivers have problems with disks above reasonable sizes.
   * Clamp the size to VAS_EBOOT_DISK_MAX_SECTORS. Just one condition is enough
   * since VAS_EBOOT_DISK_SIZE_UNKNOWN is always above VAS_EBOOT_DISK_MAX_SECTORS,
   * assuming a maximum 4 KiB sector size.
   */
  if (total_sectors > VAS_EBOOT_DISK_MAX_SECTORS)
    total_sectors = VAS_EBOOT_DISK_MAX_SECTORS;

  if ((total_sectors <= *sector
       || ((*offset + size + VAS_EBOOT_DISK_SECTOR_SIZE - 1)
	   >> VAS_EBOOT_DISK_SECTOR_BITS) > total_sectors - *sector))
    return VasEBoot_error (VAS_EBOOT_ERR_OUT_OF_RANGE,
		       N_("attempt to read or write outside of disk `%s'"), disk->name);

  return VAS_EBOOT_ERR_NONE;
}

static unsigned
VasEBoot_disk_cache_get_index (unsigned long dev_id, unsigned long disk_id,
			   VasEBoot_disk_addr_t sector)
{
  return ((dev_id * 524287UL + disk_id * 2606459UL
	   + ((unsigned) (sector >> VAS_EBOOT_DISK_CACHE_BITS)))
	  % VAS_EBOOT_DISK_CACHE_NUM);
}