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IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS IOCTL (ntddvol.h)

  • Article

Returns the physical location(s) of a volume on one or more disks. Extents are initially stored in the order in which they are created, but remirroring, splitting, or breaking a mirror, or actions taken during disaster recovery, can affect the order of disk extents.

Major code

IRP_MJ_DEVICE_CONTROL

Input buffer

None.

Input buffer length

None.

Output buffer

The driver returns a VOLUME_DISK_EXTENTS structure in the buffer at Irp->AssociatedIrp.SystemBuffer, which must be at least sizeof(VOLUME_DISK_EXTENTS).

Output buffer length

The length of a VOLUME_DISK_EXTENTS structure.

Status block

The driver sets Irp->IoStatus.Information and the Status field as follows:

  • If the buffer at Irp->AssociatedIrp.SystemBuffer is < sizeof(VOLUME_DISK_EXTENTS), the driver sets Irp->IoStatus.Information to zero and returns STATUS_INVALID_PARAMETER.
  • If the buffer at Irp->AssociatedIrp.SystemBuffer is at least sizeof(VOLUME_DISK_EXTENTS) but too small for all data to be returned, the driver sets Irp->IoStatus.Information to sizeof(VOLUME_DISK_EXTENTS) and sets Status to STATUS_BUFFER_OVERFLOW.
  • If the buffer at Irp->AssociatedIrp.SystemBuffer is large enough for all data to be returned, the driver sets Irp->IoStatus.Information to sizeof(VOLUME_DISK_EXTENTS) + ((NumberOfDiskExtents - 1) * sizeof(DISK_EXTENT)) and sets Status to STATUS_SUCCESS.

Requirements

Requirement Value
Minimum supported client Available in Microsoft Windows 2000 for volumes on fixed disks, but not for volumes on removable media. Available for use with removable media in Microsoft Windows 2000 SP4 and Windows XP SP1.
Header ntddvol.h (include Ntddvol.h)

See also

DISK_EXTENT

VOLUME_DISK_EXTENTS