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