wslinux support: ATOMIC_CREATE_ECP_CONTEXT

inc/winfsp/fsctl.h

@@ -168,7 +168,8 @@ enum
     /* additional kernel-mode flags */\
     UINT32 AllowOpenInKernelMode:1;         /* allow kernel mode to open files when possible */\
     UINT32 CasePreservedExtendedAttributes:1;   /* preserve case of EA (default is UPPERCASE) */\
-    UINT32 KmReservedFlags:6;\
+    UINT32 WslFeatures:1;                   /* support features required for WSLinux */\
+    UINT32 KmReservedFlags:5;\
     WCHAR Prefix[FSP_FSCTL_VOLUME_PREFIX_SIZE / sizeof(WCHAR)]; /* UNC prefix (\Server\Share) */\
     WCHAR FileSystemName[FSP_FSCTL_VOLUME_FSNAME_SIZE / sizeof(WCHAR)];
 #define FSP_FSCTL_VOLUME_PARAMS_V1_FIELD_DEFN\
@@ -277,7 +278,7 @@ typedef struct
             UINT32 DesiredAccess;       /* FILE_{READ_DATA,WRITE_DATA,etc.} */
             UINT32 GrantedAccess;       /* FILE_{READ_DATA,WRITE_DATA,etc.} */
             UINT32 ShareAccess;         /* FILE_SHARE_{READ,WRITE,DELETE} */
-            FSP_FSCTL_TRANSACT_BUF Ea;  /* extended attributes buffer */
+            FSP_FSCTL_TRANSACT_BUF Ea;  /* extended attributes or reparse point buffer */
             UINT32 UserMode:1;          /* request originated in user mode */
             UINT32 HasTraversePrivilege:1;  /* requestor has TOKEN_HAS_TRAVERSE_PRIVILEGE */
             UINT32 HasBackupPrivilege:1;    /* requestor has TOKEN_HAS_BACKUP_PRIVILEGE */
@@ -286,6 +287,7 @@ typedef struct
             UINT32 CaseSensitive:1;         /* FileName comparisons should be case-sensitive */
             UINT32 HasTrailingBackslash:1;  /* FileName had trailing backslash */
             UINT32 AcceptsSecurityDescriptor:1;
+            UINT32 EaIsReparsePoint:1;      /* Ea buffer is reparse point */
             UINT32 ReservedFlags:24;
             UINT16 NamedStream;             /* request targets named stream; colon offset in FileName */
         } Create;

inc/winfsp/winfsp.h

@@ -912,7 +912,8 @@ typedef struct _FSP_FILE_SYSTEM_INTERFACE
     /**
      * Create new file or directory.
      *
-     * This function works like Create, except that it also accepts EA (extended attributes).
+     * This function works like Create, except that it also accepts an extra buffer that
+     * may contain extended attributes or a reparse point.
      *
      * NOTE: If both Create and CreateEx are defined, CreateEx takes precedence.
      *
@@ -941,10 +942,12 @@ typedef struct _FSP_FILE_SYSTEM_INTERFACE
      *     Windows GetSecurityDescriptorLength API. Will be NULL for named streams.
      * @param AllocationSize
      *     Allocation size for the newly created file.
-     * @param Ea
+     * @param ExtraBuffer
-     *     Extended attributes buffer.
+     *     Extended attributes or reparse point buffer.
-     * @param EaLength
+     * @param ExtraLength
-     *     Extended attributes buffer length.
+     *     Extended attributes or reparse point buffer length.
+     * @param ExtraBufferIsReparsePoint
+     *     FALSE: extra buffer is extended attributes; TRUE: extra buffer is reparse point.
      * @param PFileContext [out]
      *     Pointer that will receive the file context on successful return from this call.
      * @param FileInfo [out]
@@ -956,7 +959,7 @@ typedef struct _FSP_FILE_SYSTEM_INTERFACE
     NTSTATUS (*CreateEx)(FSP_FILE_SYSTEM *FileSystem,
         PWSTR FileName, UINT32 CreateOptions, UINT32 GrantedAccess,
         UINT32 FileAttributes, PSECURITY_DESCRIPTOR SecurityDescriptor, UINT64 AllocationSize,
-        PFILE_FULL_EA_INFORMATION Ea, ULONG EaLength,
+        PVOID ExtraBuffer, ULONG ExtraLength, BOOLEAN ExtraBufferIsReparsePoint,
         PVOID *PFileContext, FSP_FSCTL_FILE_INFO *FileInfo);
     /**
      * Overwrite a file.

src/dll/fsop.c

@@ -443,6 +443,7 @@ static NTSTATUS FspFileSystemOpCreate_FileCreate(FSP_FILE_SYSTEM *FileSystem,
             0 != Request->Req.Create.Ea.Size ?
                 (PVOID)(Request->Buffer + Request->Req.Create.Ea.Offset) : 0,
             Request->Req.Create.Ea.Size,
+            Request->Req.Create.EaIsReparsePoint,
             AddrOfFileContext(FullContext), &OpenFileInfo.FileInfo);
     else
         Result = FileSystem->Interface->Create(FileSystem,
@@ -590,6 +591,7 @@ static NTSTATUS FspFileSystemOpCreate_FileOpenIf(FSP_FILE_SYSTEM *FileSystem,
                 0 != Request->Req.Create.Ea.Size ?
                     (PVOID)(Request->Buffer + Request->Req.Create.Ea.Offset) : 0,
                 Request->Req.Create.Ea.Size,
+                Request->Req.Create.EaIsReparsePoint,
                 AddrOfFileContext(FullContext), &OpenFileInfo.FileInfo);
         else
             Result = FileSystem->Interface->Create(FileSystem,
@@ -724,6 +726,7 @@ static NTSTATUS FspFileSystemOpCreate_FileOverwriteIf(FSP_FILE_SYSTEM *FileSyste
                 0 != Request->Req.Create.Ea.Size ?
                     (PVOID)(Request->Buffer + Request->Req.Create.Ea.Offset) : 0,
                 Request->Req.Create.Ea.Size,
+                Request->Req.Create.EaIsReparsePoint,
                 AddrOfFileContext(FullContext), &OpenFileInfo.FileInfo);
         else
             Result = FileSystem->Interface->Create(FileSystem,

src/dll/fuse/fuse_intf.c

@@ -752,7 +752,7 @@ exit:
 static NTSTATUS fsp_fuse_intf_Create(FSP_FILE_SYSTEM *FileSystem,
     PWSTR FileName, UINT32 CreateOptions, UINT32 GrantedAccess,
     UINT32 FileAttributes, PSECURITY_DESCRIPTOR SecurityDescriptor, UINT64 AllocationSize,
-    PFILE_FULL_EA_INFORMATION Ea, ULONG EaLength,
+    PVOID ExtraBuffer, ULONG ExtraLength, BOOLEAN ExtraBufferIsReparsePoint,
     PVOID *PFileDesc, FSP_FSCTL_FILE_INFO *FileInfo)
 {
     struct fuse *f = FileSystem->UserContext;
@@ -766,7 +766,9 @@ static NTSTATUS fsp_fuse_intf_Create(FSP_FILE_SYSTEM *FileSystem,
     int err;
     NTSTATUS Result;
 
-    if (0 != Ea)
+    if (0 != ExtraBuffer)
+    {
+        if (!ExtraBufferIsReparsePoint)
         {
             if (0 == f->ops.listxattr || 0 == f->ops.getxattr ||
                 0 == f->ops.setxattr || 0 == f->ops.removexattr)
@@ -775,6 +777,13 @@ static NTSTATUS fsp_fuse_intf_Create(FSP_FILE_SYSTEM *FileSystem,
                 goto exit;
             }
         }
+        else
+        {
+            /* !!!: revisit */
+            Result = STATUS_INVALID_PARAMETER;
+            goto exit;
+        }
+    }
 
     filedesc = MemAlloc(sizeof *filedesc);
     if (0 == filedesc)
@@ -889,13 +898,22 @@ static NTSTATUS fsp_fuse_intf_Create(FSP_FILE_SYSTEM *FileSystem,
             goto exit;
     }
 
-    if (0 != Ea)
+    if (0 != ExtraBuffer)
+    {
+        if (!ExtraBufferIsReparsePoint)
         {
             Result = FspFileSystemEnumerateEa(FileSystem,
-            fsp_fuse_intf_SetEaEntry, contexthdr->PosixPath, Ea, EaLength);
+                fsp_fuse_intf_SetEaEntry, contexthdr->PosixPath, ExtraBuffer, ExtraLength);
             if (!NT_SUCCESS(Result))
                 goto exit;
         }
+        else
+        {
+            /* !!!: revisit: WslFeatures, GetFileInfoFunnel, GetReparsePointEx, SetReparsePoint */
+            Result = STATUS_INVALID_PARAMETER;
+            goto exit;
+        }
+    }
     /*
      * Ignore fuse_file_info::direct_io, fuse_file_info::keep_cache.
      * NOTE: Originally WinFsp dit not support disabling the cache manager

src/dotnet/FileSystemBase.cs

@@ -1085,8 +1085,9 @@ namespace Fsp
             UInt32 FileAttributes,
             Byte[] SecurityDescriptor,
             UInt64 AllocationSize,
-            IntPtr Ea,
+            IntPtr ExtraBuffer,
-            UInt32 EaLength,
+            UInt32 ExtraLength,
+            Boolean ExtraBufferIsReparsePoint,
             out Object FileNode,
             out Object FileDesc,
             out FileInfo FileInfo,
@@ -1391,6 +1392,16 @@ namespace Fsp
             }
         }
         /// <summary>
+        /// Makes a byte array that contains a reparse point.
+        /// </summary>
+        /// <returns>The reparse point byte array.</returns>
+        public static Byte[] MakeReparsePoint(
+            IntPtr Buffer,
+            UInt32 Size)
+        {
+            return Api.MakeReparsePoint(Buffer, (UIntPtr)Size);
+        }
+        /// <summary>
         /// Gets the reparse tag from reparse data.
         /// </summary>
         /// <param name="ReparseData">

src/dotnet/FileSystemHost.cs

@@ -221,6 +221,11 @@ namespace Fsp
             get { return 0 != (_VolumeParams.Flags & VolumeParams.AllowOpenInKernelMode); }
             set { _VolumeParams.Flags |= (value ? VolumeParams.AllowOpenInKernelMode : 0); }
         }
+        public Boolean WslFeatures
+        {
+            get { return 0 != (_VolumeParams.Flags & VolumeParams.WslFeatures); }
+            set { _VolumeParams.Flags |= (value ? VolumeParams.WslFeatures : 0); }
+        }
         /// <summary>
         /// Gets or sets the prefix for a network file system.
         /// </summary>
@@ -472,8 +477,9 @@ namespace Fsp
             UInt32 FileAttributes,
             IntPtr SecurityDescriptor,
             UInt64 AllocationSize,
-            IntPtr Ea,
+            IntPtr ExtraBuffer,
-            UInt32 EaLength,
+            UInt32 ExtraLength,
+            Boolean ExtraBufferIsReparsePoint,
             ref FullContext FullContext,
             ref OpenFileInfo OpenFileInfo)
         {
@@ -490,8 +496,9 @@ namespace Fsp
                     FileAttributes,
                     Api.MakeSecurityDescriptor(SecurityDescriptor),
                     AllocationSize,
-                    Ea,
+                    ExtraBuffer,
-                    EaLength,
+                    ExtraLength,
+                    ExtraBufferIsReparsePoint,
                     out FileNode,
                     out FileDesc,
                     out OpenFileInfo.FileInfo,

src/dotnet/Interop.cs

@@ -53,6 +53,7 @@ namespace Fsp.Interop
         internal const UInt32 UmFileContextIsFullContext = 0x00020000;
         internal const UInt32 AllowOpenInKernelMode = 0x01000000;
         internal const UInt32 CasePreservedExtendedAttributes = 0x02000000;
+        internal const UInt32 WslFeatures = 0x04000000;
         internal const int PrefixSize = 192;
         internal const int FileSystemNameSize = 16;
 
@@ -557,8 +558,9 @@ namespace Fsp.Interop
                 UInt32 FileAttributes,
                 IntPtr SecurityDescriptor,
                 UInt64 AllocationSize,
-                IntPtr Ea,
+                IntPtr ExtraBuffer,
-                UInt32 EaLength,
+                UInt32 ExtraLength,
+                [MarshalAs(UnmanagedType.U1)] Boolean ExtraBufferIsReparsePoint,
                 ref FullContext FullContext,
                 ref OpenFileInfo OpenFileInfo);
             [UnmanagedFunctionPointer(CallingConvention.Cdecl)]

src/sys/create.c

@@ -29,7 +29,7 @@ static NTSTATUS FspFsvolCreate(
     PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
 static NTSTATUS FspFsvolCreateNoLock(
     PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp,
-    BOOLEAN MainFileOpen);
+    BOOLEAN MainFileOpen, PFSP_ATOMIC_CREATE_ECP_CONTEXT AtomicCreateEcp);
 FSP_IOPREP_DISPATCH FspFsvolCreatePrepare;
 FSP_IOCMPL_DISPATCH FspFsvolCreateComplete;
 static NTSTATUS FspFsvolCreateTryOpen(PIRP Irp, const FSP_FSCTL_TRANSACT_RSP *Response,
@@ -144,6 +144,7 @@ static NTSTATUS FspFsvolCreate(
     PECP_LIST ExtraCreateParameters;
     PVOID ExtraCreateParameter;
     BOOLEAN MainFileOpen = FALSE;
+    PFSP_ATOMIC_CREATE_ECP_CONTEXT AtomicCreateEcp = 0;
 
     /*
      * Check if the IRP has ECP's.
@@ -219,6 +220,21 @@ static NTSTATUS FspFsvolCreate(
             }
         }
 #endif
+
+        if (FspFsvolDeviceExtension(FsvolDeviceObject)->VolumeParams.WslFeatures)
+        {
+            // {4720bd83-52ac-4104-a130-d1ec6a8cc8e5}
+            static const GUID FspAtomicCreateEcpGuid =
+                { 0x4720bd83, 0x52ac, 0x4104, { 0xa1, 0x30, 0xd1, 0xec, 0x6a, 0x8c, 0xc8, 0xe5 } };
+
+            ExtraCreateParameter = 0;
+            AtomicCreateEcp =
+                NT_SUCCESS(FsRtlFindExtraCreateParameter(ExtraCreateParameters,
+                    &FspAtomicCreateEcpGuid, &ExtraCreateParameter, 0)) &&
+                0 != ExtraCreateParameter &&
+                !FsRtlIsEcpFromUserMode(ExtraCreateParameter) ?
+                    ExtraCreateParameter : 0;
+        }
     }
 
     if (!MainFileOpen)
@@ -226,7 +242,8 @@ static NTSTATUS FspFsvolCreate(
         FspFsvolDeviceFileRenameAcquireShared(FsvolDeviceObject);
         try
         {
-            Result = FspFsvolCreateNoLock(FsvolDeviceObject, Irp, IrpSp, FALSE);
+            Result = FspFsvolCreateNoLock(FsvolDeviceObject, Irp, IrpSp,
+                MainFileOpen, AtomicCreateEcp);
         }
         finally
         {
@@ -235,14 +252,15 @@ static NTSTATUS FspFsvolCreate(
         }
     }
     else
-        Result = FspFsvolCreateNoLock(FsvolDeviceObject, Irp, IrpSp, TRUE);
+        Result = FspFsvolCreateNoLock(FsvolDeviceObject, Irp, IrpSp,
+            MainFileOpen, AtomicCreateEcp);
 
     return Result;
 }
 
 static NTSTATUS FspFsvolCreateNoLock(
     PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp,
-    BOOLEAN MainFileOpen)
+    BOOLEAN MainFileOpen, PFSP_ATOMIC_CREATE_ECP_CONTEXT AtomicCreateEcp)
 {
     PAGED_CODE();
 
@@ -279,6 +297,8 @@ static NTSTATUS FspFsvolCreateNoLock(
     USHORT ShareAccess = IrpSp->Parameters.Create.ShareAccess;
     PFILE_FULL_EA_INFORMATION EaBuffer = Irp->AssociatedIrp.SystemBuffer;
     ULONG EaLength = IrpSp->Parameters.Create.EaLength;
+    PVOID ExtraBuffer = 0;
+    ULONG ExtraLength = 0;
     ULONG Flags = IrpSp->Flags;
     KPROCESSOR_MODE RequestorMode =
         FlagOn(Flags, SL_FORCE_ACCESS_CHECK) ? UserMode : Irp->RequestorMode;
@@ -292,6 +312,7 @@ static NTSTATUS FspFsvolCreateNoLock(
     BOOLEAN HasRestorePrivilege =
         BooleanFlagOn(AccessState->Flags, TOKEN_HAS_RESTORE_PRIVILEGE);
     BOOLEAN HasTrailingBackslash = FALSE;
+    BOOLEAN EaIsReparsePoint = FALSE;
     FSP_FILE_NODE *FileNode, *RelatedFileNode;
     FSP_FILE_DESC *FileDesc;
     UNICODE_STRING MainFileName = { 0 }, StreamPart = { 0 };
@@ -302,6 +323,36 @@ static NTSTATUS FspFsvolCreateNoLock(
     if (FlagOn(CreateOptions, FILE_OPEN_BY_FILE_ID))
         return STATUS_NOT_IMPLEMENTED;
 
+    /* is there an AtomicCreateEcp attached? */
+    if (0 != AtomicCreateEcp)
+    {
+        if ((FILE_CREATE != CreateDisposition && FILE_OPEN_IF != CreateDisposition) ||
+            0 != EaBuffer ||
+            RTL_SIZEOF_THROUGH_FIELD(FSP_ATOMIC_CREATE_ECP_CONTEXT, ReparseBuffer) >
+                AtomicCreateEcp->Size ||
+            /* !!!: revisit: FlagOn*/
+            !FlagOn(AtomicCreateEcp->InFlags,
+                ATOMIC_CREATE_ECP_IN_FLAG_BEST_EFFORT |
+                ATOMIC_CREATE_ECP_IN_FLAG_REPARSE_POINT_SPECIFIED))
+            return STATUS_INVALID_PARAMETER; /* docs do not say what to return on failure! */
+
+        if (FlagOn(AtomicCreateEcp->InFlags,
+            ATOMIC_CREATE_ECP_IN_FLAG_REPARSE_POINT_SPECIFIED))
+        {
+            Result = FsRtlValidateReparsePointBuffer(AtomicCreateEcp->ReparseBufferLength,
+                AtomicCreateEcp->ReparseBuffer);
+            if (!NT_SUCCESS(Result))
+                return Result;
+
+            /* mark that we satisfied the reparse point request, although we may fail it later! */
+            AtomicCreateEcp->OutFlags = ATOMIC_CREATE_ECP_OUT_FLAG_REPARSE_POINT_SET;
+
+            ExtraBuffer = AtomicCreateEcp->ReparseBuffer;
+            ExtraLength = AtomicCreateEcp->ReparseBufferLength;
+            EaIsReparsePoint = TRUE;
+        }
+    }
+
     /* was an EA buffer specified? */
     if (0 != EaBuffer)
     {
@@ -318,6 +369,9 @@ static NTSTATUS FspFsvolCreateNoLock(
             EaBuffer, EaLength, (PULONG)&Irp->IoStatus.Information);
         if (!NT_SUCCESS(Result))
             return Result;
+
+        ExtraBuffer = EaBuffer;
+        ExtraLength = EaLength;
     }
 
     /* cannot open a paging file */
@@ -555,9 +609,9 @@ static NTSTATUS FspFsvolCreateNoLock(
         SecurityDescriptorSize = 0;
         FileAttributes = 0;
 
-        /* cannot set EA on named stream */
+        /* cannot set extra buffer on named stream */
-        EaBuffer = 0;
+        ExtraBuffer = 0;
-        EaLength = 0;
+        ExtraLength = 0;
 
         /* remember the main file node */
         ASSERT(0 == FileNode->MainFileNode);
@@ -577,8 +631,8 @@ static NTSTATUS FspFsvolCreateNoLock(
 
     /* create the user-mode file system request */
     Result = FspIopCreateRequestEx(Irp, &FileNode->FileName,
-        0 != EaBuffer ?
+        0 != ExtraBuffer ?
-            FSP_FSCTL_DEFAULT_ALIGN_UP(SecurityDescriptorSize) + EaLength : SecurityDescriptorSize,
+            FSP_FSCTL_DEFAULT_ALIGN_UP(SecurityDescriptorSize) + ExtraLength : SecurityDescriptorSize,
         FspFsvolCreateRequestFini, &Request);
     if (!NT_SUCCESS(Result))
     {
@@ -616,10 +670,10 @@ static NTSTATUS FspFsvolCreateNoLock(
     Request->Req.Create.DesiredAccess = DesiredAccess;
     Request->Req.Create.GrantedAccess = GrantedAccess;
     Request->Req.Create.ShareAccess = ShareAccess;
-    Request->Req.Create.Ea.Offset = 0 != EaBuffer ?
+    Request->Req.Create.Ea.Offset = 0 != ExtraBuffer ?
         (0 != Request->Req.Create.SecurityDescriptor.Offset ?
             NEXTOFS(Request->Req.Create.SecurityDescriptor) : NEXTOFS(Request->FileName)) : 0;
-    Request->Req.Create.Ea.Size = 0 != EaBuffer ? (UINT16)EaLength : 0;
+    Request->Req.Create.Ea.Size = 0 != ExtraBuffer ? (UINT16)ExtraLength : 0;
     Request->Req.Create.UserMode = UserMode == RequestorMode;
     Request->Req.Create.HasTraversePrivilege = HasTraversePrivilege;
     Request->Req.Create.HasBackupPrivilege = HasBackupPrivilege;
@@ -628,10 +682,10 @@ static NTSTATUS FspFsvolCreateNoLock(
     Request->Req.Create.CaseSensitive = CaseSensitive;
     Request->Req.Create.HasTrailingBackslash = HasTrailingBackslash;
     Request->Req.Create.NamedStream = MainFileName.Length;
-#undef NEXTOFS
-
     Request->Req.Create.AcceptsSecurityDescriptor = 0 == Request->Req.Create.NamedStream &&
         !!FsvolDeviceExtension->VolumeParams.AllowOpenInKernelMode;
+    Request->Req.Create.EaIsReparsePoint = EaIsReparsePoint;
+#undef NEXTOFS
 
     ASSERT(
         0 == StreamPart.Length && 0 == MainFileName.Length ||
@@ -642,10 +696,10 @@ static NTSTATUS FspFsvolCreateNoLock(
         RtlCopyMemory(Request->Buffer + Request->Req.Create.SecurityDescriptor.Offset,
             SecurityDescriptor, SecurityDescriptorSize);
 
-    /* copy the EA buffer (if any) into the request */
+    /* copy the extra buffer (if any) into the request */
-    if (0 != EaBuffer)
+    if (0 != ExtraBuffer)
         RtlCopyMemory(Request->Buffer + Request->Req.Create.Ea.Offset,
-            EaBuffer, EaLength);
+            ExtraBuffer, ExtraLength);
 
     /* fix FileNode->FileName if we are doing SL_OPEN_TARGET_DIRECTORY */
     if (Request->Req.Create.OpenTargetDirectory)

src/sys/driver.h

@@ -1678,4 +1678,39 @@ typedef struct
     ULONG LxDeviceIdMajor;
     ULONG LxDeviceIdMinor;
 } FSP_FILE_STAT_LX_INFORMATION, *PFSP_FILE_STAT_LX_INFORMATION;
+
+/* ATOMIC_CREATE_ECP_CONTEXT is missing on some WDK's */
+#define ATOMIC_CREATE_ECP_IN_FLAG_REPARSE_POINT_SPECIFIED   0x0002
+#define ATOMIC_CREATE_ECP_OUT_FLAG_REPARSE_POINT_SET        0x0002
+#define ATOMIC_CREATE_ECP_IN_FLAG_BEST_EFFORT               0x0100
+typedef struct
+{
+    LARGE_INTEGER CreationTime;
+    LARGE_INTEGER LastAccessTime;
+    LARGE_INTEGER LastWriteTime;
+    LARGE_INTEGER ChangeTime;
+} FSP_FILE_TIMESTAMPS, *PFSP_FILE_TIMESTAMPS;
+typedef struct
+{
+    USHORT Size;
+    USHORT InFlags;
+    USHORT OutFlags;
+    USHORT ReparseBufferLength;
+    PREPARSE_DATA_BUFFER ReparseBuffer;
+    LONGLONG FileSize;
+    LONGLONG ValidDataLength;
+    PFSP_FILE_TIMESTAMPS FileTimestamps;
+    ULONG FileAttributes;
+    ULONG UsnSourceInfo;
+    USN Usn;
+    ULONG SuppressFileAttributeInheritanceMask;
+    ULONG InOpFlags;
+    ULONG OutOpFlags;
+    ULONG InGenFlags;
+    ULONG OutGenFlags;
+    ULONG CaseSensitiveFlagsMask;
+    ULONG InCaseSensitiveFlags;
+    ULONG OutCaseSensitiveFlags;
+} FSP_ATOMIC_CREATE_ECP_CONTEXT, *PFSP_ATOMIC_CREATE_ECP_CONTEXT;
+
 #endif

src/sys/fileinfo.c

@@ -981,10 +981,16 @@ static NTSTATUS FspFsvolQueryInformation(
         Result = FspFsvolQueryStandardInformation(FileObject, &Buffer, BufferEnd, 0);
         break;
     case 68/*FileStatInformation*/:
+        if (FspFsvolDeviceExtension(FsvolDeviceObject)->VolumeParams.WslFeatures)
             Result = FspFsvolQueryStatBaseInformation(FileObject, &Buffer, BufferEnd, 0);
+        else
+            Result = STATUS_INVALID_PARAMETER;
         break;
     case 70/*FileStatLxInformation*/:
+        if (FspFsvolDeviceExtension(FsvolDeviceObject)->VolumeParams.WslFeatures)
             Result = FspFsvolQueryStatLxBaseInformation(FileObject, &Buffer, BufferEnd, 0);
+        else
+            Result = STATUS_INVALID_PARAMETER;
         break;
     default:
         Result = STATUS_INVALID_PARAMETER;

tst/memfs-dotnet/Program.cs

@@ -274,6 +274,7 @@ namespace memfs
             Host.PostCleanupWhenModifiedOnly = true;
             Host.PassQueryDirectoryFileName = true;
             Host.ExtendedAttributes = true;
+            Host.WslFeatures = true;
             return STATUS_SUCCESS;
         }
 
@@ -331,8 +332,9 @@ namespace memfs
             UInt32 FileAttributes,
             Byte[] SecurityDescriptor,
             UInt64 AllocationSize,
-            IntPtr Ea,
+            IntPtr ExtraBuffer,
-            UInt32 EaLength,
+            UInt32 ExtraLength,
+            Boolean ExtraBufferIsReparsePoint,
             out Object FileNode0,
             out Object FileDesc,
             out FileInfo FileInfo,
@@ -369,12 +371,22 @@ namespace memfs
             FileNode.FileInfo.FileAttributes = 0 != (FileAttributes & (UInt32)System.IO.FileAttributes.Directory) ?
                 FileAttributes : FileAttributes | (UInt32)System.IO.FileAttributes.Archive;
             FileNode.FileSecurity = SecurityDescriptor;
-            if (IntPtr.Zero != Ea)
+            if (IntPtr.Zero != ExtraBuffer)
             {
-                Result = SetEaEntries(FileNode, null, Ea, EaLength);
+                if (!ExtraBufferIsReparsePoint)
+                {
+                    Result = SetEaEntries(FileNode, null, ExtraBuffer, ExtraLength);
                     if (0 > Result)
                         return Result;
                 }
+                else
+                {
+                    Byte[] ReparseData = MakeReparsePoint(ExtraBuffer, ExtraLength);
+                    FileNode.FileInfo.FileAttributes |= (UInt32)System.IO.FileAttributes.ReparsePoint;
+                    FileNode.FileInfo.ReparseTag = GetReparseTag(ReparseData);
+                    FileNode.ReparseData = ReparseData;
+                }
+            }
             if (0 != AllocationSize)
             {
                 Result = SetFileSizeInternal(FileNode, AllocationSize, true);

tst/memfs/memfs.cpp

@@ -69,6 +69,11 @@ FSP_FSCTL_STATIC_ASSERT(MEMFS_MAX_PATH > MAX_PATH,
  */
 #define MEMFS_EA
 
+/*
+ * Define the MEMFS_WSL macro to include WSLinux support.
+ */
+#define MEMFS_WSL
+
  /*
  * Define the DEBUG_BUFFER_CHECK macro on Windows 8 or above. This includes
  * a check for the Write buffer to ensure that it is read-only.
@@ -1047,8 +1052,8 @@ static NTSTATUS GetSecurityByName(FSP_FILE_SYSTEM *FileSystem,
 static NTSTATUS Create(FSP_FILE_SYSTEM *FileSystem,
     PWSTR FileName, UINT32 CreateOptions, UINT32 GrantedAccess,
     UINT32 FileAttributes, PSECURITY_DESCRIPTOR SecurityDescriptor, UINT64 AllocationSize,
-#if defined(MEMFS_EA)
+#if defined(MEMFS_EA) || defined(MEMFS_WSL)
-    PFILE_FULL_EA_INFORMATION Ea, ULONG EaLength,
+    PVOID ExtraBuffer, ULONG ExtraLength, BOOLEAN ExtraBufferIsReparsePoint,
 #endif
     PVOID *PFileNode, FSP_FSCTL_FILE_INFO *FileInfo)
 {
@@ -1129,10 +1134,14 @@ static NTSTATUS Create(FSP_FILE_SYSTEM *FileSystem,
         memcpy(FileNode->FileSecurity, SecurityDescriptor, FileNode->FileSecuritySize);
     }
 
-#if defined(MEMFS_EA)
+#if defined(MEMFS_EA) || defined(MEMFS_WSL)
-    if (0 != Ea)
+    if (0 != ExtraBuffer)
     {
-        Result = FspFileSystemEnumerateEa(FileSystem, MemfsFileNodeSetEa, FileNode, Ea, EaLength);
+#if defined(MEMFS_EA)
+        if (!ExtraBufferIsReparsePoint)
+        {
+            Result = FspFileSystemEnumerateEa(FileSystem, MemfsFileNodeSetEa, FileNode,
+                (PFILE_FULL_EA_INFORMATION)ExtraBuffer, ExtraLength);
             if (!NT_SUCCESS(Result))
             {
                 MemfsFileNodeDelete(FileNode);
@@ -1140,6 +1149,30 @@ static NTSTATUS Create(FSP_FILE_SYSTEM *FileSystem,
             }
         }
 #endif
+#if defined(MEMFS_WSL)
+        if (ExtraBufferIsReparsePoint)
+        {
+#if defined(MEMFS_REPARSE_POINTS)
+            FileNode->ReparseDataSize = ExtraLength;
+            FileNode->ReparseData = malloc(ExtraLength);
+            if (0 == FileNode->ReparseData && 0 != ExtraLength)
+            {
+                MemfsFileNodeDelete(FileNode);
+                return STATUS_INSUFFICIENT_RESOURCES;
+            }
+
+            FileNode->FileInfo.FileAttributes |= FILE_ATTRIBUTE_REPARSE_POINT;
+            FileNode->FileInfo.ReparseTag = *(PULONG)ExtraBuffer;
+                /* the first field in a reparse buffer is the reparse tag */
+            memcpy(FileNode->ReparseData, ExtraBuffer, ExtraLength);
+#else
+            MemfsFileNodeDelete(FileNode);
+            return STATUS_INVALID_PARAMETER;
+#endif
+        }
+#endif
+    }
+#endif
 
     FileNode->FileInfo.AllocationSize = AllocationSize;
     if (0 != FileNode->FileInfo.AllocationSize)
@@ -2189,7 +2222,7 @@ static FSP_FILE_SYSTEM_INTERFACE MemfsInterface =
     GetVolumeInfo,
     SetVolumeLabel,
     GetSecurityByName,
-#if defined(MEMFS_EA)
+#if defined(MEMFS_EA) || defined(MEMFS_WSL)
     0,
 #else
     Create,
@@ -2240,8 +2273,10 @@ static FSP_FILE_SYSTEM_INTERFACE MemfsInterface =
     0,
 #endif
     0,
-#if defined(MEMFS_EA)
+#if defined(MEMFS_EA) || defined(MEMFS_WSL)
     Create,
+#endif
+#if defined(MEMFS_EA)
     Overwrite,
     GetEa,
     SetEa
@@ -2347,6 +2382,9 @@ NTSTATUS MemfsCreateFunnel(
 #endif
 #if defined(MEMFS_EA)
     VolumeParams.ExtendedAttributes = 1;
+#endif
+#if defined(MEMFS_WSL)
+    VolumeParams.WslFeatures = 1;
 #endif
     VolumeParams.AllowOpenInKernelMode = 1;
     if (0 != VolumePrefix)