mapping partitions starting from PhysicalDrive

Question

I want to map all partitions from all drives in Windows (the ones who are not mapped already). I mean I want to assign to each of them drive letters. I know that you can do

Answer 1

Maybe my Change DriveLetter commandline tool can help you, at least you can start it with commandline parameters and see if it lists all volumes you expect.

This link might also be useful: Converting a volume name to a devicename

Answer 2

I did it :) I made a program who adds or removes drive letters when it's started - if one or more storage drives were added or removed from the computer:

program MapDrives;

uses Windows;

type
   TPARTITION_INFORMATION = record
      StartingOffset: _LARGE_INTEGER; //TLargeInteger;
      PartitionLength: _LARGE_INTEGER; //TLargeInteger;
      HiddenSectors: DWORD;
      PartitionNumber: DWORD;
      PartitionType: BYTE;
      BootIndicator: BOOLEAN;
      RecognizedPartition: BOOLEAN;
      RewritePartition: BOOLEAN;
   end;

function IntToStr(Value: Integer): string;
begin
   if Value < 10 then
      Result := Char(Value + 48)
   else
      Result := Char(Value div 10 + 48) + Char(Value + 48);
end;

function GetNextAvailableLetter: AnsiChar;
var Drives, mask: DWord;
   i: Integer;
begin
   Drives := GetLogicalDrives;
   mask := 4;
   Result := 'Z';
   for i := 3 to 26 do //C to Z
   begin
      if mask and Drives = 0 then
      begin
         Result := AnsiChar(64 + i);
         Exit;
      end;
      mask := mask shl 1;
   end;
end;


const IOCTL_DISK_GET_PARTITION_INFO = $0074004;

var i, j, k: Integer;
   H: THandle;
   dwBytesReturned: DWORD;
   BreakCycle, DoMount: Boolean;
   NextLetter: AnsiChar;
   PartitionInformation: TPARTITION_INFORMATION;
   PartitionsInformation: array of TPARTITION_INFORMATION;
   Drives, mask: DWord;
   OldMode: UINT;

begin
   OldMode := SetErrorMode(SEM_FAILCRITICALERRORS); //so it shouldn't ask to insert CD or card

   //gets informations about already mounted partitions
   SetLength(PartitionsInformation, 0);
   Drives := GetLogicalDrives;
   mask := 4;
   for i := 3 to 26 do //C to Z
   begin
      if mask and Drives <> 0 then
      begin
         H := CreateFile(PAnsiChar('\\.\' + Char(64 + i) + ':'), GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0);
         if H <> INVALID_HANDLE_VALUE then
         begin
            SetLength(PartitionsInformation, Length(PartitionsInformation) + 1);
            DeviceIoControl(H, IOCTL_DISK_GET_PARTITION_INFO, nil, 0, @PartitionsInformation[High(PartitionsInformation)], SizeOf(TPARTITION_INFORMATION), dwBytesReturned, nil);
            CloseHandle(H);
         end
         else     //removes unaccessible drives
            DefineDosDevice(DDD_REMOVE_DEFINITION or DDD_RAW_TARGET_PATH, PAnsiChar(string(Char(64 + i) + ':')), nil);
      end;
      mask := mask shl 1;
   end;

   for i := 0 to 99 do
   begin
      H := CreateFile(PAnsiChar('\\.\PhysicalDrive' + IntToStr(i)), GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0);
      if H = INVALID_HANDLE_VALUE then //no more hdd's
         Break;
      CloseHandle(H);
      for j := 1 to 20 do
      begin
         BreakCycle := False;
         NextLetter := GetNextAvailableLetter;
         DefineDosDevice(DDD_RAW_TARGET_PATH or DDD_NO_BROADCAST_SYSTEM, PAnsiChar(string(NextLetter + ':')), PAnsiChar('\Device\Harddisk' + IntToStr(i) + '\Partition' + IntToStr(j)));
         DoMount := True;
         H := CreateFile(PAnsiChar('\\.\' + NextLetter + ':'), GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, 0, 0);
         if H = INVALID_HANDLE_VALUE then //no more partitions
            BreakCycle := True
         else
         begin
            PartitionInformation.PartitionType := 0;
            DeviceIoControl(H, IOCTL_DISK_GET_PARTITION_INFO, nil, 0, @PartitionInformation, SizeOf(TPARTITION_INFORMATION), dwBytesReturned, nil);
            DoMount := PartitionInformation.PartitionType in [0, 1, 6, 7, 11, 12, 114];
            CloseHandle(H);
         end;
         if DoMount then
         begin
            for k := 0 to High(PartitionsInformation) do  //compare with already mounted partitions
               if (PartitionsInformation[k].StartingOffset.LowPart = PartitionInformation.StartingOffset.LowPart) and
                  (PartitionsInformation[k].StartingOffset.HighPart = PartitionInformation.StartingOffset.HighPart) and
                  (PartitionsInformation[k].StartingOffset.QuadPart = PartitionInformation.StartingOffset.QuadPart) and
                  (PartitionsInformation[k].PartitionLength.LowPart = PartitionInformation.PartitionLength.LowPart) and
                  (PartitionsInformation[k].PartitionLength.HighPart = PartitionInformation.PartitionLength.HighPart) and
                  (PartitionsInformation[k].PartitionLength.QuadPart = PartitionInformation.PartitionLength.QuadPart) and
                  (PartitionsInformation[k].HiddenSectors = PartitionInformation.HiddenSectors) and
                  (PartitionsInformation[k].PartitionType = PartitionInformation.PartitionType) and
                  (PartitionsInformation[k].BootIndicator = PartitionInformation.BootIndicator) and
                  (PartitionsInformation[k].RecognizedPartition = PartitionInformation.RecognizedPartition) then
                  Break;
            DoMount := k > High(PartitionsInformation);
         end;
         DefineDosDevice(DDD_REMOVE_DEFINITION or DDD_RAW_TARGET_PATH, PAnsiChar(string(NextLetter + ':')), nil);
         if (not BreakCycle) and DoMount then
            DefineDosDevice(DDD_RAW_TARGET_PATH, PAnsiChar(string(NextLetter + ':')), PAnsiChar('\Device\Harddisk' + IntToStr(i) + '\Partition' + IntToStr(j)));
         if BreakCycle then
            Break;
      end;
   end;
   SetErrorMode(OldMode); //restore original mode
end.

On the computers that I mentioned it works perfectly.

Thank you guys for all your ideas which helped me to make this code.

If someone notice some bugs or has any good ideas about how to improve it, I'll be glad to fix/implement them.

Answer 3

You can do This using WMI.
In library GLibWMI (http://neftali.clubdelphi.com or SourceForge) you can find the TDiskPartitionInfo and TDiskDriveInfo.
The first can give you the created partitions and all of your properties.
Test the Generic Sample and check the results. In an partitioned disk like this:

You obtains 4 instantes with the properties of 4 partitions like this:

The library it's totally free and source is avaible. Check the samples.
You can find some other codes to access this information using WMI. If you want use another, you can search for "WMI and Win32_DiskPartition Class" (Link doc).

Excuse-me for mistakes with English.
Regards