public static List <DiskExtent> GetUnallocatedExtents(Disk disk)
{
MasterBootRecord mbr = MasterBootRecord.ReadFromDisk(disk);
List <DiskExtent> result = new List <DiskExtent>();
if (mbr == null)
{
result.Add(new DiskExtent(disk, 0, disk.Size));
return(result);
}
else
{
long dataRegionStartSector;
long dataRegionSize;
if (!mbr.IsGPTBasedDisk)
{
dataRegionStartSector = MBRDiskFirstUsableSector;
dataRegionSize = Math.Min(disk.Size, UInt32.MaxValue * disk.BytesPerSector) - dataRegionStartSector;
}
else
{
GuidPartitionTableHeader gptHeader = GuidPartitionTableHeader.ReadFromDisk(disk);
dataRegionStartSector = (long)gptHeader.FirstUsableLBA;
dataRegionSize = (long)(gptHeader.LastUsableLBA - gptHeader.FirstUsableLBA + 1) * disk.BytesPerSector;
}
List <Partition> partitions = GetPartitions(disk);
List <DiskExtent> usedExtents = new List <DiskExtent>();
foreach (Partition partition in partitions)
{
usedExtents.Add(partition.Extent);
}
return(DiskExtentsHelper.GetUnallocatedExtents(disk, dataRegionStartSector, dataRegionSize, usedExtents));
}
}
/// <returns>Number of bytes</returns>
public static long GetMaximumSizeToExtendGPTPartition(GPTPartition partition)
{
GuidPartitionTableHeader header = GuidPartitionTableHeader.ReadFromDisk(partition.Disk);
long partitonEndSector = partition.FirstSector + partition.Size / partition.BytesPerSector;
// Prevent from extending beyond the secondary GPT header / partition array
long max = ((long)header.LastUsableLBA + 1) * partition.BytesPerSector - (partition.FirstSector * partition.BytesPerSector + partition.Size);
List <GuidPartitionEntry> entries = GuidPartitionTable.ReadEntriesFromDisk(partition.Disk);
foreach (GuidPartitionEntry entry in entries)
{
if ((long)entry.FirstLBA > partition.FirstSector)
{
long available = ((long)entry.FirstLBA - partition.FirstSector) * partition.BytesPerSector - partition.Size;
max = Math.Min(max, available);
}
}
return(max);
}
