IOCTL_MOUNTDEV_QUERY_UNIQUE_ID IOCTL (mountdev.h)
IOCTL_MOUNTDEV_QUERY_UNIQUE_ID retrieves a unique identifier for a device or volume.
Mount manager clients must support this IOCTL. Upon receiving this IOCTL, the mount manager client must provide a counted byte string identifier that is unique to the client (that is, the device or the volume).
None.
None.
The device class or volume driver returns the MOUNTDEV_UNIQUE_ID structure in the buffer at Irp->AssociatedIrp.SystemBuffer.
Parameters.DeviceIoControl.OutputBufferLength in the I/O stack location of the IRP indicates the size, in bytes, of the output buffer, which must be greater than or equal to sizeof(MOUNTDEV_UNIQUE_ID)
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N/A
N/A
The Information field is set to FIELD_OFFSET(MOUNTDEV_UNIQUE_ID, UniqueId) + output->UniqueIdLength; or alternatively to sizeof(USHORT) + output->UniqueIdLength, where output points to the buffer at Irp->AssociatedIrp.SystemBuffer.
The implementer of this function must not thread synchronize and must not make blocking and/or Interprocess Communication (IPC) function calls.
For more information, see Supporting Mount Manager Requests in a Storage Class Driver.
Requirement | Value |
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Header | mountdev.h (include Mountdev.h) |