4.2

4 files changed, 361 insertions, 144 deletions

diff --git a/lib/ShadowCopy/Shadow_2003.vcxproj b/lib/ShadowCopy/Shadow_Server2003.vcxproj
index a893a389..a893a389 100644
--- a/lib/ShadowCopy/Shadow_2003.vcxproj
+++ b/lib/ShadowCopy/Shadow_Server2003.vcxproj
diff --git a/lib/ShadowCopy/Shadow_Windows7.vcxproj b/lib/ShadowCopy/Shadow_Windows7.vcxproj
new file mode 100644
index 00000000..2392fa99
--- /dev/null
+++ b/lib/ShadowCopy/Shadow_Windows7.vcxproj
@@ -0,0 +1,241 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectName>Windows7</ProjectName>
+    <ProjectGuid>{7E217D76-90A5-4B03-A6F8-E7C3ADD22901}</ProjectGuid>
+    <RootNamespace>ShadowDll</RootNamespace>
+    <Keyword>Win32Proj</Keyword>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <UseOfAtl>false</UseOfAtl>
+    <PlatformToolset>Windows7.1SDK</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+    <PlatformToolset>Windows7.1SDK</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <PlatformToolset>Windows7.1SDK</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
+    <ConfigurationType>DynamicLibrary</ConfigurationType>
+    <CharacterSet>Unicode</CharacterSet>
+    <PlatformToolset>Windows7.1SDK</PlatformToolset>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup>
+    <_ProjectFileVersion>10.0.30319.1</_ProjectFileVersion>
+    <OutDir Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">OBJ\</OutDir>
+    <IntDir Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">OBJ\$(ProjectName)_$(Configuration)_$(Platform)\</IntDir>
+    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">false</LinkIncremental>
+    <OutDir Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">OBJ\</OutDir>
+    <IntDir Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">OBJ\$(ProjectName)_$(Configuration)_$(Platform)\</IntDir>
+    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</LinkIncremental>
+    <OutDir Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">.\</OutDir>
+    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">OBJ\$(ProjectName)_$(Configuration)_$(Platform)\</IntDir>
+    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">false</LinkIncremental>
+    <OutDir Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\</OutDir>
+    <IntDir Condition="'$(Configuration)|$(Platform)'=='Release|x64'">OBJ\$(ProjectName)_$(Configuration)_$(Platform)\</IntDir>
+    <LinkIncremental Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</LinkIncremental>
+    <TargetName Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">Shadow_$(ProjectName)_$(Platform)</TargetName>
+    <TargetName Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">Shadow_$(ProjectName)_$(Platform)</TargetName>
+    <TargetName Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">Shadow_$(ProjectName)_$(Platform)</TargetName>
+    <TargetName Condition="'$(Configuration)|$(Platform)'=='Release|x64'">Shadow_$(ProjectName)_$(Platform)</TargetName>
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <BuildLog>
+      <Path>$(IntDir)Build.html</Path>
+    </BuildLog>
+    <ClCompile>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>_DEBUG;_WINDOWS;_USRDLL;SHADOWDLL_EXPORTS;USE_SHADOW_WINDOWS7;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <MinimalRebuild>true</MinimalRebuild>
+      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <DebugInformationFormat>EditAndContinue</DebugInformationFormat>
+      <DisableSpecificWarnings>4100;4996</DisableSpecificWarnings>
+      <AdditionalIncludeDirectories>../..</AdditionalIncludeDirectories>
+    </ClCompile>
+    <Link>
+      <OutputFile>$(OutDir)$(TargetName)$(TargetExt)</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <ProgramDatabaseFile>$(IntDir)$(TargetName).pdb</ProgramDatabaseFile>
+      <SubSystem>Windows</SubSystem>
+      <ProfileGuidedDatabase>
+      </ProfileGuidedDatabase>
+      <ImportLibrary>$(IntDir)$(TargetName).lib</ImportLibrary>
+      <TargetMachine>MachineX86</TargetMachine>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <BuildLog>
+      <Path>$(IntDir)Build.html</Path>
+    </BuildLog>
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <Optimization>Disabled</Optimization>
+      <MinimalRebuild>true</MinimalRebuild>
+      <BasicRuntimeChecks>EnableFastChecks</BasicRuntimeChecks>
+      <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <DisableSpecificWarnings>4100;4996</DisableSpecificWarnings>
+      <AdditionalIncludeDirectories>../..</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>_DEBUG;_WINDOWS;_USRDLL;SHADOWDLL_EXPORTS;USE_SHADOW_WINDOWS7;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+    </ClCompile>
+    <Link>
+      <OutputFile>$(OutDir)$(TargetName)$(TargetExt)</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <ProgramDatabaseFile>$(IntDir)$(TargetName).pdb</ProgramDatabaseFile>
+      <SubSystem>Windows</SubSystem>
+      <ProfileGuidedDatabase>
+      </ProfileGuidedDatabase>
+      <ImportLibrary>$(IntDir)$(TargetName).lib</ImportLibrary>
+      <TargetMachine>MachineX64</TargetMachine>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <BuildLog>
+      <Path>$(IntDir)Build.html</Path>
+    </BuildLog>
+    <ClCompile>
+      <Optimization>MaxSpeed</Optimization>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <PreprocessorDefinitions>NDEBUG;_WINDOWS;_USRDLL;SHADOWDLL_EXPORTS;USE_SHADOW_WINDOWS7;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <FavorSizeOrSpeed>Speed</FavorSizeOrSpeed>
+      <DisableSpecificWarnings>4100;4996</DisableSpecificWarnings>
+      <AdditionalIncludeDirectories>../..</AdditionalIncludeDirectories>
+    </ClCompile>
+    <Link>
+      <OutputFile>$(OutDir)$(TargetName)$(TargetExt)</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <GenerateDebugInformation>false</GenerateDebugInformation>
+      <SubSystem>Windows</SubSystem>
+      <OptimizeReferences>true</OptimizeReferences>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
+      <ProfileGuidedDatabase>
+      </ProfileGuidedDatabase>
+      <ImportLibrary>$(IntDir)$(TargetName).lib</ImportLibrary>
+      <TargetMachine>MachineX86</TargetMachine>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <BuildLog>
+      <Path>$(IntDir)Build.html</Path>
+    </BuildLog>
+    <Midl>
+      <TargetEnvironment>X64</TargetEnvironment>
+    </Midl>
+    <ClCompile>
+      <Optimization>MaxSpeed</Optimization>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <PrecompiledHeader>
+      </PrecompiledHeader>
+      <WarningLevel>Level4</WarningLevel>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <FavorSizeOrSpeed>Speed</FavorSizeOrSpeed>
+      <DisableSpecificWarnings>4100;4996</DisableSpecificWarnings>
+      <AdditionalIncludeDirectories>../..</AdditionalIncludeDirectories>
+      <PreprocessorDefinitions>NDEBUG;_WINDOWS;_USRDLL;SHADOWDLL_EXPORTS;USE_SHADOW_WINDOWS7;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+    </ClCompile>
+    <Link>
+      <OutputFile>$(OutDir)$(TargetName)$(TargetExt)</OutputFile>
+      <SuppressStartupBanner>true</SuppressStartupBanner>
+      <GenerateDebugInformation>false</GenerateDebugInformation>
+      <SubSystem>Windows</SubSystem>
+      <OptimizeReferences>true</OptimizeReferences>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <LinkTimeCodeGeneration>UseLinkTimeCodeGeneration</LinkTimeCodeGeneration>
+      <ProfileGuidedDatabase>
+      </ProfileGuidedDatabase>
+      <ImportLibrary>$(IntDir)$(TargetName).lib</ImportLibrary>
+      <TargetMachine>MachineX64</TargetMachine>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="dll_main.cpp">
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+      </PrecompiledHeader>
+      <CompileAsManaged Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">false</CompileAsManaged>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+      </PrecompiledHeader>
+      <CompileAsManaged Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">false</CompileAsManaged>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+      </PrecompiledHeader>
+      <CompileAsManaged Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">false</CompileAsManaged>
+      <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+      </PrecompiledHeader>
+      <CompileAsManaged Condition="'$(Configuration)|$(Platform)'=='Release|x64'">false</CompileAsManaged>
+    </ClCompile>
+    <ClCompile Include="shadow.cpp" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="shadow.h" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>
\ No newline at end of file
diff --git a/lib/ShadowCopy/shadow.cpp b/lib/ShadowCopy/shadow.cpp
index 12e9fa60..5047a698 100644
--- a/lib/ShadowCopy/shadow.cpp
+++ b/lib/ShadowCopy/shadow.cpp
@@ -7,12 +7,9 @@
 #include "shadow.h"
 #include <algorithm>
 #include <string>
-#include <comdef.h>
 #include <zen/com_ptr.h>
 #include <zen/com_error.h>
-
-#define WIN32_LEAN_AND_MEAN
-#include "windows.h"
+#include <zen/scope_guard.h>
 
 #ifdef USE_SHADOW_XP
 #include "xp/inc/vss.h"
@@ -23,13 +20,30 @@
 #include "Server 2003/inc/vss.h"
 #include "Server 2003/inc/vswriter.h"
 #include "Server 2003/inc/vsbackup.h"
+
+#elif defined USE_SHADOW_WINDOWS7
+#include <vss.h>      //
+#include <vswriter.h> //part of Windows SDK for Windows 7
+#include <vsbackup.h> //
+#pragma comment(lib, "VssApi.lib")
+
 #else
-adapt!
+#error adapt!
 #endif
 
 using namespace zen;
 
 
+struct shadow::ShadowData
+{
+    ShadowData(const ComPtr<IVssBackupComponents>& backupComp,
+               const std::wstring& shadowVolume) : backupComp_(backupComp), shadowVolume_(shadowVolume) {}
+
+    ComPtr<IVssBackupComponents> backupComp_;
+    std::wstring shadowVolume_;
+};
+
+
 namespace
 {
 inline
@@ -45,143 +59,99 @@ void copyString(const std::wstring& input, wchar_t* buffer, size_t bufferSize)
     }
 }
 
-inline
-void writeErrorMsg(const wchar_t* input, HRESULT hr, wchar_t* output, unsigned int outputLen)
-{
-    copyString(generateErrorMsg(input, hr), output, outputLen);
-}
-}
-
 
-bool shadow::createShadowCopy(const wchar_t* volumeName,
-                              wchar_t*		 shadowVolName,
-                              unsigned int   shadowBufferLen,
-                              ShadowHandle*	 handle,
-                              wchar_t*		 errorMessage,
-                              unsigned int	 errorBufferLen)
+shadow::ShadowData createShadowCopy(const wchar_t* volumeName) //throw ComError
 {
-    //MessageBox(0, L"backup err", L"", 0); */
-    *handle    = 0;
-    HRESULT hr = NULL;
-
     ComPtr<IVssBackupComponents> backupComp;
-    if (FAILED(hr = CreateVssBackupComponents(backupComp.init())))
     {
-        if (hr == E_ACCESSDENIED)
-            writeErrorMsg(L"The caller does not have sufficient backup privileges or is not an administrator.", hr, errorMessage, errorBufferLen);
-        else
-            writeErrorMsg(L"Error calling \"CreateVssBackupComponents\".", hr, errorMessage, errorBufferLen);
-        return false;
+        HRESULT hr = ::CreateVssBackupComponents(backupComp.init());
+        if (FAILED(hr))
+        {
+            if (hr == E_ACCESSDENIED)
+                throw ComError(L"The caller does not have sufficient backup privileges or is not an administrator.", hr);
+            throw ComError(L"Error calling \"CreateVssBackupComponents\".", hr);
+        }
     }
 
-    if (FAILED(hr = backupComp->InitializeForBackup()))
-    {
-        writeErrorMsg(L"Error calling \"InitializeForBackup\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+    ZEN_CHECK_COM(backupComp->InitializeForBackup()); //throw ComError
+    ZEN_CHECK_COM(backupComp->SetBackupState(false, false, VSS_BT_FULL)); //throw ComError
 
-    if (FAILED(hr = backupComp->SetBackupState(false, false, VSS_BT_FULL)))
+    auto waitForComFuture = [](IVssAsync& fut)
     {
-        writeErrorMsg(L"Error calling \"SetBackupState\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+        ZEN_CHECK_COM(fut.Wait());
 
-    ComPtr<IVssAsync> vssWriters;
-    if (FAILED(hr = backupComp->GatherWriterMetadata(vssWriters.init())))
-    {
-        //this can happen if XP-version of VSS is used on Windows Vista (which needs at least VSS-Server2003 build)
-        writeErrorMsg(L"Error calling \"GatherWriterMetadata\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+        HRESULT hr = S_OK;
+        ZEN_CHECK_COM(fut.QueryStatus(&hr, NULL)); //check if the async operation succeeded...
+        if (FAILED(hr))
+            throw ComError(L"Error calling \"fut->QueryStatus\".", hr);
+    };
 
-    //wait for shadow copy writers to complete
-    if (FAILED(hr = vssWriters->Wait()))
-    {
-        writeErrorMsg(L"Error calling \"vssWriters->Wait\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+    ComPtr<IVssAsync> gatherAsync;
+    ZEN_CHECK_COM(backupComp->GatherWriterMetadata(gatherAsync.init()));
+    waitForComFuture(*gatherAsync); //failure can happen if XP-version of VSS is used on Windows Vista (which needs at least VSS-Server2003 build)
 
-    vssWriters->QueryStatus(&hr, NULL); //check if the async operation succeeded...
-    if (FAILED(hr))
-    {
-        writeErrorMsg(L"Error calling \"vssWriters->QueryStatus\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+    VSS_ID snapshotSetId = {};
+    ZEN_CHECK_COM(backupComp->StartSnapshotSet(&snapshotSetId));
+    ScopeGuard guardSnapShot = makeGuard([&]() { backupComp->AbortBackup(); });
+    //Quote: "This method must be called if a backup operation terminates after the creation of a
+    //shadow copy set with "StartSnapshotSet" and before "DoSnapshotSet" returns."
 
-    VSS_ID snapshotSetId = {0};
-    if (FAILED(hr = backupComp->StartSnapshotSet(&snapshotSetId)))
+    VSS_ID SnapShotId = {};
     {
-        writeErrorMsg(L"Error calling \"StartSnapshotSet\".", hr, errorMessage, errorBufferLen);
-        return false;
+        HRESULT hr = backupComp->AddToSnapshotSet(const_cast<wchar_t*>(volumeName), GUID_NULL, &SnapShotId);
+        if (FAILED(hr))
+        {
+            if (hr == VSS_E_VOLUME_NOT_SUPPORTED)
+                throw ComError(L"Volume Shadow Copy Service is not supported on this volume!");
+            throw ComError(L"Error calling \"backupComp->AddToSnapshotSet\".", hr);
+        }
     }
 
-    VSS_ID SnapShotId = {0};
-    if (FAILED(hr = backupComp->AddToSnapshotSet(const_cast<wchar_t*>(volumeName), GUID_NULL, &SnapShotId)))
-    {
-        writeErrorMsg(L"Error calling \"AddToSnapshotSet\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+    ComPtr<IVssAsync> prepareAsync;
+    ZEN_CHECK_COM(backupComp->PrepareForBackup(prepareAsync.init()));
+    waitForComFuture(*prepareAsync);
 
-    ComPtr<IVssAsync> vssPrepare;
-    if (FAILED(hr = backupComp->PrepareForBackup(vssPrepare.init())))
-    {
-        writeErrorMsg(L"Error calling \"PrepareForBackup\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+    ComPtr<IVssAsync> snapshotAsync;
+    ZEN_CHECK_COM(backupComp->DoSnapshotSet(snapshotAsync.init()));
+    guardSnapShot.dismiss();
+    waitForComFuture(*snapshotAsync);
 
-    if (FAILED(hr = vssPrepare->Wait()))
-    {
-        writeErrorMsg(L"Error calling \"vssPrepare->Wait\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+    VSS_SNAPSHOT_PROP props = {};
+    ZEN_CHECK_COM(backupComp->GetSnapshotProperties(SnapShotId, &props));
+    ZEN_ON_BLOCK_EXIT(::VssFreeSnapshotProperties(&props));
 
-    vssPrepare->QueryStatus(&hr, NULL); //check if the async operation succeeded...
-    if (FAILED(hr))
-    {
-        writeErrorMsg(L"Error calling \"vssPrepare->QueryStatus\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
-
-    ComPtr<IVssAsync> vssDoShadowCopy;
-    if (FAILED(hr = backupComp->DoSnapshotSet(vssDoShadowCopy.init())))
-    {
-        writeErrorMsg(L"Error calling \"DoSnapshotSet\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
+    //finally: write volume name of newly created shadow copy
+    return shadow::ShadowData(backupComp, props.m_pwszSnapshotDeviceObject);
+}
+}
 
-    if (FAILED(hr = vssDoShadowCopy->Wait()))
-    {
-        writeErrorMsg(L"Error calling \"vssDoShadowCopy->Wait\".", hr, errorMessage, errorBufferLen);
-        return false;
-    }
 
-    vssDoShadowCopy->QueryStatus(&hr, NULL); //check if the async operation succeeded...
-    if (FAILED(hr))
+shadow::ShadowHandle shadow::createShadowCopy(const wchar_t* volumeName,
+                                              wchar_t*		 errorMessage,
+                                              unsigned int	 errorBufferLen)
+{
+    try
     {
-        writeErrorMsg(L"Error calling \"vssDoShadowCopy->QueryStatus\".", hr, errorMessage, errorBufferLen);
-        return false;
+        ShadowData result = ::createShadowCopy(volumeName); //shadow handle owned by caller! throw ComError
+        return new ShadowData(result);
     }
-
-    VSS_SNAPSHOT_PROP props;
-    if (FAILED(hr = backupComp->GetSnapshotProperties(SnapShotId, &props)))
+    catch (const zen::ComError& e)
     {
-        writeErrorMsg(L"Error calling \"GetSnapshotProperties\".", hr, errorMessage, errorBufferLen);
-        return false;
+        copyString(e.toString(), errorMessage, errorBufferLen);
+        return nullptr;
     }
+}
 
-    //finally: write volume name of newly created shadow copy
-    copyString(props.m_pwszSnapshotDeviceObject, shadowVolName, shadowBufferLen);
-
-    VssFreeSnapshotProperties(&props);
-
-    *handle = backupComp.release();
 
-    return true;
+void shadow::getShadowVolume(shadow::ShadowHandle handle,
+                             wchar_t*		 buffer,
+                             unsigned int   bufferLen)
+{
+    copyString(handle->shadowVolume_, buffer, bufferLen);
 }
 
 
 void shadow::releaseShadowCopy(ShadowHandle handle)
 {
-    if (handle)
-        handle->Release();
+    delete handle;
 }
diff --git a/lib/ShadowCopy/shadow.h b/lib/ShadowCopy/shadow.h
index 0dfd39a9..68b7141f 100644
--- a/lib/ShadowCopy/shadow.h
+++ b/lib/ShadowCopy/shadow.h
@@ -26,23 +26,23 @@ namespace shadow
   --------------*/
 
 //COM needs to be initialized before calling any of these functions! CoInitializeEx/CoUninitialize
+struct ShadowData;
+typedef ShadowData* ShadowHandle;
 
-typedef IVssBackupComponents* ShadowHandle;
-
-//volumeName must end with "\", while shadowVolName does not end with "\"
+//volumeName *must* end with "\"
 SHADOWDLL_API
-bool createShadowCopy(const wchar_t* volumeName,      // in
-                      wchar_t*		 shadowVolName,   // out
-                      unsigned int   shadowBufferLen, // in
-                      ShadowHandle*	 handle,          // out
-                      wchar_t*		 errorMessage,    // out
-                      unsigned int	 errorBufferLen); // in
-
+ShadowHandle createShadowCopy(const wchar_t* volumeName,      // in  Returns nullptr on failure!
+                              wchar_t*		 errorMessage,    // out
+                              unsigned int	 errorBufferLen); // in
 
 //don't forget to release the backupHandle after shadow copy is not needed anymore!
 SHADOWDLL_API
 void releaseShadowCopy(ShadowHandle handle);
 
+SHADOWDLL_API
+void getShadowVolume(ShadowHandle handle, //shadowVolName does *not* end with "\"
+                     wchar_t*	  buffer,
+                     unsigned int bufferLen);
 
 //##########################################################################################
 
@@ -50,21 +50,24 @@ void releaseShadowCopy(ShadowHandle handle);
 /*----------
   |typedefs|
   ----------*/
-typedef bool (*CreateShadowCopyFct)(const wchar_t* volumeName,
-                                    wchar_t*	   shadowVolName,
-                                    unsigned int   shadowBufferLen,
-                                    ShadowHandle*  handle,
-                                    wchar_t*	   errorMessage,
-                                    unsigned int   errorBufferLen);
+typedef ShadowHandle (*CreateShadowCopyFct)(const wchar_t* volumeName,
+                                            wchar_t*	    errorMessage,
+                                            unsigned int   errorBufferLen);
 
 typedef void (*ReleaseShadowCopyFct)(ShadowHandle handle);
 
+typedef void (*GetShadowVolumeFct)(ShadowHandle handle,
+                                   wchar_t*	   buffer,
+                                   unsigned int bufferLen);
+
+
 /*--------------
   |symbol names|
   --------------*/
 //(use const pointers to ensure internal linkage)
-const char createShadowCopyFctName[]  = "createShadowCopy";
+const char createShadowCopyFctName [] = "createShadowCopy";
 const char releaseShadowCopyFctName[] = "releaseShadowCopy";
+const char getShadowVolumeFctName  [] = "getShadowVolume";
 
 /*---------------
   |library names|
@@ -73,21 +76,24 @@ const char releaseShadowCopyFctName[] = "releaseShadowCopy";
 inline
 const wchar_t* getDllName()
 {
-    /*
-    distinguish a bunch of VSS builds: we use XP and Server 2003 implementations...
-    VSS version and compatibility overview: http://msdn.microsoft.com/en-us/library/aa384627(VS.85).aspx
-    */
-    return zen::winServer2003orLater() ?
-           (zen::is64BitBuild ?
-            L"Shadow_Server2003_x64.dll" :
-            L"Shadow_Server2003_Win32.dll") :
-
-               (zen::is64BitBuild ?
-                L"Shadow_XP_x64.dll" :
-                L"Shadow_XP_Win32.dll");
+    // distinguish a bunch of VSS builds: we use XP, Server 2003 and Server 2008 R2 implementations...
+    // VSS version and compatibility overview: http://msdn.microsoft.com/en-us/library/aa384627(VS.85).aspx
+
+    if (zen::win7OrLater()) //Windows Server 2008 R2 or Windows 7
+        return zen::is64BitBuild ?
+               L"Shadow_Windows7_x64.dll" :
+               L"Shadow_Windows7_Win32.dll";
+    //else if (vistaOrLater()) -> skip Windows Server 2008 and Windows Vista
+    //			   ;
+    else if (zen::winServer2003orLater()) //Windows Server 2003 and Windows Server 2003 R2
+        return zen::is64BitBuild ?
+               L"Shadow_Server2003_x64.dll" :
+               L"Shadow_Server2003_Win32.dll";
+    else //Windows XP
+        return zen::is64BitBuild ?
+               L"Shadow_XP_x64.dll" :
+               L"Shadow_XP_Win32.dll";
 }
 }
 
-
-
 #endif //SHADOWCOPY_H