MOUNTMGR_MOUNT_POINT - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTIOAPI_H

// Input structure for IOCTL_MOUNTMGR_DELETE_POINTS, IOCTL_MOUNTMGR_QUERY_POINTS, and IOCTL_MOUNTMGR_DELETE_POINTS_DBONLY.
typedef struct _MOUNTMGR_MOUNT_POINT
{
    ULONG SymbolicLinkNameOffset;
    USHORT SymbolicLinkNameLength;
    USHORT Reserved1;
    ULONG UniqueIdOffset;
    USHORT UniqueIdLength;
    USHORT Reserved2;
    ULONG DeviceNameOffset;
    USHORT DeviceNameLength;
    USHORT Reserved3;
} MOUNTMGR_MOUNT_POINT, *PMOUNTMGR_MOUNT_POINT;

#endif

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This structure is documented in Windows Driver Kit.