Network Redirector Drivers 固有の動作

IRP_MJ_QUERY_INFORMATION
https://msdn.microsoft.com/ja-jp/library/ff549283(v=vs.85).aspx

Operation: Network Redirector Drivers
「A network redirector driver not based on RDBSS that receives an IRP_MJ_QUERY_INFORMATION request for FileAllInformation or FileNameInformation, must respond with the full "\server\share\file" path for the file name with a single leading backslash before the server name. This format for name information must be returned for a file accessed as a Universal Naming Convention (UNC) name (\\server\share\folder\filename.txt, for example) or a file located on a mapped drive (x:\folder\filename.txt, for example).」

FileNameInformation 対応が必要。