The IEnumDiskQuotaUsers interface enumerates user quota entries on the volume. This interface is instantiated by using the IDiskQuotaControl::CreateEnumUsers method.
QueryInterface
AddRef
Release
To use this interface, the client directs an object that maintains a collection of items to create an enumerator object. By repeatedly calling the Next method, the client gets successive pointers to each item in the collection.
File Systems Overview, File System Interfaces