gistfile1.txt

BOOL InternalDeleteFileW(_In_ PCWSTR lpFileName)
{
	union {
		FILE_ATTRIBUTE_TAG_INFORMATION attr;
		FILE_DISPOSITION_INFORMATION_EX fdi;
	};

	UNICODE_STRING ObjectName;
	NTSTATUS status = RtlDosPathNameToNtPathName_U_WithStatus(lpFileName, &ObjectName, 0, 0);

	if (0 <= status)
	{
		OBJECT_ATTRIBUTES oa = { sizeof(oa), 0, &ObjectName, OBJ_CASE_INSENSITIVE };
		IO_STATUS_BLOCK iosb;
		HANDLE hFile;

		if (0 <= (status = NtOpenFile(&hFile, DELETE|FILE_READ_ATTRIBUTES, &oa, &iosb, FILE_SHARE_READ, 
			FILE_OPEN_REPARSE_POINT|FILE_OPEN_FOR_BACKUP_INTENT|FILE_NON_DIRECTORY_FILE)))
		{
			if (0 <= (status = NtQueryInformationFile(hFile, &iosb, &attr, sizeof(attr), FileAttributeTagInformation)))
			{
				if (attr.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT)
				{
					switch (attr.ReparseTag)
					{
					case IO_REPARSE_TAG_MOUNT_POINT:
					case IO_REPARSE_TAG_SYMLINK:
					case IO_REPARSE_TAG_GLOBAL_REPARSE:
						break;
					default:
						NtClose(hFile);
						if (0 > (status = NtOpenFile(&hFile, DELETE, &oa, 
							&iosb, FILE_SHARE_READ, FILE_OPEN_FOR_BACKUP_INTENT|FILE_NON_DIRECTORY_FILE)))
						{
							switch (status)
							{
							case STATUS_IO_REPARSE_TAG_INVALID:
							case STATUS_IO_REPARSE_DATA_INVALID:
							case STATUS_IO_REPARSE_TAG_NOT_HANDLED:
								if (0 <= (status = NtOpenFile(&hFile, DELETE, &oa, &iosb, FILE_SHARE_READ, 
									FILE_OPEN_REPARSE_POINT|FILE_OPEN_FOR_BACKUP_INTENT|FILE_NON_DIRECTORY_FILE)))
								{
									break;
								}
							default:
								goto __exit;
							}
						}
						break;
					}
				}

				fdi.Flags = FILE_DISPOSITION_DELETE|FILE_DISPOSITION_POSIX_SEMANTICS;
				status = NtSetInformationFile(hFile, &iosb, &fdi, sizeof(fdi), FileDispositionInformationEx);
			}

			NtClose(hFile);
		}

__exit:
		RtlFreeUnicodeString(&ObjectName);
	}

	return NOERROR == RtlNtStatusToDosError(status);
}

//*****************************************************************************************************************
// https://github.com/wisny101/Windows-Server-2003-Source/blob/master/base/ntos/io/iomgr/iosubs.c#L3567

    if (Irp->Flags & IRP_ASSOCIATED_IRP) {
		//...
    }

    //
    // Check to see if we have a name junction. If so set the stage to
    // transmogrify the reparse point data in IopCompleteRequest.
    //

    if ((Irp->IoStatus.Status == STATUS_REPARSE )  &&
        (Irp->IoStatus.Information > IO_REPARSE_TAG_RESERVED_RANGE)) {
			
		switch (Irp->IoStatus.Information)
		{
		case IO_REPARSE_TAG_MOUNT_POINT:
		case IO_REPARSE_TAG_SYMLINK:
		case IO_REPARSE_TAG_GLOBAL_REPARSE:
            //
            // For name junctions, we save the pointer to the auxiliary
            // buffer and use it below.
            //

            ASSERT( Irp->Tail.Overlay.AuxiliaryBuffer != NULL );

            saveAuxiliaryPointer = (PVOID) Irp->Tail.Overlay.AuxiliaryBuffer;

            //
            // We NULL the entry to avoid its de-allocation at this time.
            // This buffer get deallocated in IopDoNameTransmogrify
            //

            Irp->Tail.Overlay.AuxiliaryBuffer = NULL;
			break;
			
		default:
            //
            // Fail the request. A driver needed to act on this IRP prior
            // to getting to this point.
            //

            Irp->IoStatus.Status = STATUS_IO_REPARSE_TAG_NOT_HANDLED;
		}
    }