tools: add batch file that fixes issue #162

According to the FILE_BASIC_INFORMATION doc a file system should not update a file timestamp when it receives a value of -1 in the corresponding time field.

This commit converts a -1 timestamp to a 0 timestamp; this directs a WinFsp file system not to update the corresponding file timestamp.

This commit fixes issue #362

src/shared/ku/posix.c

@@ -123,9 +123,12 @@ static struct
     PWSTR DnsDomainName;
     ULONG TrustPosixOffset;
 } *FspTrustedDomains;
-ULONG FspTrustedDomainCount;
+static ULONG FspTrustedDomainCount;
+static BOOLEAN FspDistinctPermsForSameOwnerGroup;
 static INIT_ONCE FspPosixInitOnce = INIT_ONCE_STATIC_INIT;
+
 #if !defined(_KERNEL_MODE)
+
 static ULONG FspPosixInitializeTrustPosixOffsets(VOID)
 {
     PVOID Ldap = 0;
@@ -169,6 +172,28 @@ exit:
     return LdapResult;
 }
 
+static VOID FspPosixInitializeFromRegistry(VOID)
+{
+    HKEY RegKey;
+    LONG Result;
+    DWORD Size;
+    DWORD DistinctPermsForSameOwnerGroup;
+
+    DistinctPermsForSameOwnerGroup = 0;
+
+    Result = RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"Software\\WinFsp",
+        0, KEY_READ | KEY_WOW64_32KEY, &RegKey);
+    if (ERROR_SUCCESS == Result)
+    {
+        Size = sizeof DistinctPermsForSameOwnerGroup;
+        Result = RegGetValueW(RegKey, 0, L"DistinctPermsForSameOwnerGroup",
+            RRF_RT_REG_DWORD, 0, &DistinctPermsForSameOwnerGroup, &Size);
+        RegCloseKey(RegKey);
+    }
+
+    FspDistinctPermsForSameOwnerGroup = !!DistinctPermsForSameOwnerGroup;
+}
+
 static BOOL WINAPI FspPosixInitialize(
     PINIT_ONCE InitOnce, PVOID Parameter, PVOID *Context)
 {
@@ -300,6 +325,8 @@ static BOOL WINAPI FspPosixInitialize(
     if (0 < FspTrustedDomainCount)
         FspPosixInitializeTrustPosixOffsets();
 
+    FspPosixInitializeFromRegistry();
+
 exit:
     if (0 != TrustedDomains)
         NetApiBufferFree(TrustedDomains);
@@ -330,7 +357,9 @@ VOID FspPosixFinalize(BOOLEAN Dynamic)
         MemFree(FspPrimaryDomainSid);
     }
 }
+
 #else
+
 ULONG NTAPI FspPosixInitialize(
     PRTL_RUN_ONCE RunOnce, PVOID Parameter, PVOID *Context)
 {
@@ -376,8 +405,12 @@ ULONG NTAPI FspPosixInitialize(
         FspPrimaryDomainSid = &FspPrimaryDomainSidBuf.V;
     }
 
+    /* always enable permissive permissions for same owner group in kernel mode */
+    FspDistinctPermsForSameOwnerGroup = TRUE;
+
     return TRUE;
 }
+
 #endif
 
 static inline BOOLEAN FspPosixIsRelativeSid(PISID Sid1, PISID Sid2)
@@ -778,7 +811,7 @@ FSP_API NTSTATUS FspPosixMapPermissionsToSecurityDescriptor(
      * bits are different?. In this case, the most restrictive permissions
      * are chosen and assigned to both ACEs.
      */
-    if (EqualSid(OwnerSid, GroupSid))
+    if (!FspDistinctPermsForSameOwnerGroup && EqualSid(OwnerSid, GroupSid))
         OwnerPerm = GroupPerm = OwnerPerm & GroupPerm;
 
     /* [PERMS]

src/sys/fileinfo.c

@@ -1288,10 +1288,31 @@ static NTSTATUS FspFsvolSetBasicInformation(PFILE_OBJECT FileObject,
         }
 
         Request->Req.SetInformation.Info.Basic.FileAttributes = FileAttributes;
-        Request->Req.SetInformation.Info.Basic.CreationTime = Info->CreationTime.QuadPart;
+
-        Request->Req.SetInformation.Info.Basic.LastAccessTime = Info->LastAccessTime.QuadPart;
+        /*
-        Request->Req.SetInformation.Info.Basic.LastWriteTime = Info->LastWriteTime.QuadPart;
+         * From FILE_BASIC_INFORMATION (https://tinyurl.com/hwex4bd9):
-        Request->Req.SetInformation.Info.Basic.ChangeTime = Info->ChangeTime.QuadPart;
+         *
+         * The file system updates the values of the LastAccessTime,
+         * LastWriteTime, and ChangeTime members as appropriate after an I/O
+         * operation is performed on a file. A driver or application can
+         * request that the file system not update one or more of these
+         * members for I/O operations that are performed on the caller's file
+         * handle by setting the appropriate members to -1. The caller can set
+         * one, all, or any other combination of these three members to -1.
+         * Only the members that are set to -1 will be unaffected by I/O
+         * operations on the file handle; the other members will be updated as
+         * appropriate.
+         *
+         * GitHub issue #362
+         */
+        Request->Req.SetInformation.Info.Basic.CreationTime =
+            -1 != Info->CreationTime.QuadPart ? Info->CreationTime.QuadPart : 0;
+        Request->Req.SetInformation.Info.Basic.LastAccessTime =
+            -1 != Info->LastAccessTime.QuadPart ? Info->LastAccessTime.QuadPart : 0;
+        Request->Req.SetInformation.Info.Basic.LastWriteTime =
+            -1 != Info->LastWriteTime.QuadPart ? Info->LastWriteTime.QuadPart : 0;
+        Request->Req.SetInformation.Info.Basic.ChangeTime =
+            -1 != Info->ChangeTime.QuadPart ? Info->ChangeTime.QuadPart : 0;
     }
     else
     {

tools/fix162.bat

@@ -0,0 +1,51 @@
+@echo off
+
+REM This script is used to fix GitHub issue #162:
+REM     https://github.com/billziss-gh/winfsp/issues/162
+REM
+REM It works as follows:
+REM
+REM     - Creates a junction called `amd64` inside the `WinFsp\bin` directory
+REM that points back to the directory.
+REM
+REM - Updates the registry `ProviderPath` of the WinFsp Network Provider to
+REM point to `...\bin\%PROCESSOR_ARCHITECTURE%\winfsp-x64.dll`.
+REM
+REM It requires Administrator privileges in order to run.
+
+setlocal
+setlocal EnableDelayedExpansion
+
+set RegKey="HKLM\SOFTWARE\WinFsp"
+set RegVal="InstallDir"
+reg query !RegKey! /v !RegVal! /reg:32 >nul 2>&1
+if !ERRORLEVEL! equ 0 (
+	for /f "tokens=2,*" %%i in ('reg query !RegKey! /v !RegVal! /reg:32 ^| findstr !RegVal!') do (
+		set InstallDir=%%j
+	)
+)
+if not exist "!InstallDir!" (echo cannot find WinFsp installation >&2 & goto fail)
+
+set RegKey="HKLM\SYSTEM\CurrentControlSet\Services\WinFsp.Np\NetworkProvider"
+set RegVal="ProviderPath"
+
+if not X%1==X-u (
+	echo fix #162
+
+	if not exist "!InstallDir!bin\amd64" mklink /j "!InstallDir!bin\amd64" "!InstallDir!bin"
+
+	reg add !RegKey! /v !RegVal! /t REG_EXPAND_SZ /d "!InstallDir!bin\%%PROCESSOR_ARCHITECTURE%%\winfsp-x64.dll" /f
+
+) else (
+	echo undo fix #162
+
+	if exist "!InstallDir!bin\amd64" rmdir "!InstallDir!bin\amd64"
+
+	reg add !RegKey! /v !RegVal! /t REG_SZ /d "!InstallDir!bin\winfsp-x64.dll" /f
+
+)
+
+exit /b 0
+
+:fail
+exit /b 1