The IOCTL_DISK_GET_DRIVE_LAYOUT DeviceIoControl operation returns information about the number of partitions on a disk and the features of each partition.
dwIoControlCode = IOCTL_DISK_GET_DRIVE_LAYOUT; // operation code
lpInBuffer = NULL; // address of input buffer; not used; must be NULL
nInBufferSize = 0; // size of input buffer; not used; must be zero
lpOutBuffer ; // address of output buffer
nOutBufferSize ; // size of output buffer
lpBytesReturned ; // address of actual bytes of output
Parameters
lpInBuffer
Points to an input buffer. Not used with this operation. Set to NULL.
nInBufferSize
Specifies the size, in bytes, of the buffer pointed to by lpInBuffer. Not used with this operation. Set to zero.
lpOutBuffer
Points to a buffer that will receive a DRIVE_LAYOUT_INFORMATION structure and a series of PARTITION_INFORMATION structures, one of the latter for each partition on the drive.
nOutBufferSize
Specifies the size, in bytes, of the buffer pointed to by lpOutBuffer, which must be large enough to contain one DRIVE_LAYOUT_INFORMATION data structure and as many PARTITION_INFORMATION data structures as there are partitions on the drive.
lpBytesReturned
Points to a DWORD that receives the actual size, in bytes, of the data stored into lpOutBuffer.
Return Values
If the operation succeeds, DeviceIoControl returns TRUE.
If the operation fails, DeviceIoControl returns FALSE. To get extended error information, call GetLastError.
Remarks
This device I/O control operation is for disk devices. Floppy disk drivers, however, do not need to handle this operation.
See Also
DeviceIoControl, DRIVE_LAYOUT_INFORMATION, IOCTL_DISK_SET_DRIVE_LAYOUT, PARTITION_INFORMATION