How to acquire ext2 partition size?

Hello,

I'm writing a program to make images from CompactFlash cards and vice versa. With the following code I get the list of available devices:

Code:

void win32_get_drives()
{
	HANDLE cf_card;
	DWORD rc, dwError, dwRead;
	char devices[100000];
	char drive[MAX_PATH + 1];
	char drive_full[MAX_PATH + 1 + 10];
	char drive_to_open[MAX_PATH + 1 + 8];
	char lpBuf[BUF_SIZE + 1];
	char *tmp_str, *idx;
	
	cout << "Available devices:" << endl << "\t";

	rc = QueryDosDevice(NULL, devices, sizeof(devices));
	if(rc == 0)
	{
		dwError = GetLastError();
		cout << "Error querying devices (" << dwError << ")" << endl;
		exit(0);
	}

	tmp_str = devices;
	while(1)
	{

		idx = strstr(tmp_str, "PhysicalDrive");	
		if(idx == NULL)
		{
			if(tmp_str[1] == '\0')
				break;
			tmp_str += strlen(tmp_str) + 1;
			continue;
		}

		strcpy(drive, idx);

		sprintf(drive_full, "\\\\.\\%s\\", drive);
		rc = GetDriveType(drive_full);
		if(rc == DRIVE_REMOVABLE)
		{
			// open CompactFlash card
			sprintf(drive_to_open, "\\\\.\\%s", drive);
			cf_card = CreateFile(drive_to_open,  
						GENERIC_READ,
						0, 
						NULL, 
						OPEN_EXISTING,
						FILE_ATTRIBUTE_NORMAL,
						NULL);

			if (cf_card != INVALID_HANDLE_VALUE)
			{
				rc = ReadFile(cf_card,lpBuf,BUF_SIZE,&dwRead,NULL);
				if(rc) 
					cout << drive;

				CloseHandle(cf_card);
			}
		}

		tmp_str += strlen(tmp_str) + 1;
	}

	cout << endl;
}

How can I acquire the size of the ext2 partition? My program can only handle 512Mb cards.

Thanks

Why are you asking about ext2 on a Windows forum?

Because I need a program that works under Windows. For Linux I don't even need to write a program. It is everything there in the system utilities.

In Windows it is a little bit complicated with device name and so on. But I need such a program for our customers that runs under Windows.

Why should you care about ext2 if you're making an image of the disk/card? Just read the size of the disk, and image the entire thing.

If you must only image a single partition (how many flash cards have more than one partition? Although I've never seen a flash card with ext2 on it either...) then you'll need to read & parse the partition table - search google or wikipedia to find a specification.

I've found it. It is IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS (http://msdn2.microsoft.com/en-US/library/aa365194.aspx). With this IOCTL I can get the size of the CF card. See the code:

Code:

void small_test(char * DeviceName)
{
	HANDLE file;
	VOLUME_DISK_EXTENTS OutBuffer;
	DWORD OutBufferSize = sizeof(OutBuffer);
	DWORD BytesReturned;
	

	file = CreateFile(DeviceName,  
						GENERIC_READ, 
						FILE_SHARE_READ,  
						NULL, 
						OPEN_EXISTING,
						FILE_ATTRIBUTE_NORMAL,
						NULL);


	if (DeviceIoControl(file,IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS, NULL, 0, &OutBuffer, OutBufferSize, &BytesReturned, NULL))
	{
		cout << "O.K.\n";
		cout << "NumberOfDisExtents: " << OutBuffer.NumberOfDiskExtents << endl;
		cout << "DiskNumber: " << OutBuffer.Extents[0].DiskNumber << endl; 
		cout << "ExtentLength: " << OutBuffer.Extents[0].ExtentLength.QuadPart << endl; 
		cout << "StartingOffset: " << OutBuffer.Extents[0].StartingOffset.QuadPart << endl; 
	}
	else
	{
		cout << "FAILED\n";
	}

	CloseHandle(file);
}

Best regards,
pupkin