sys: FspFsextProvider: load provider driver

src/sys/device.c

@@ -329,7 +329,7 @@ static NTSTATUS FspFsvolDeviceInit(PDEVICE_OBJECT DeviceObject)
     if (0 != FsvolDeviceExtension->VolumeParams.FsextControlCode)
     {
         FSP_FSEXT_PROVIDER *Provider = FspFsextProvider(
-            FsvolDeviceExtension->VolumeParams.FsextControlCode);
+            FsvolDeviceExtension->VolumeParams.FsextControlCode, &Result);
         if (0 != Provider)
         {
             Result = Provider->DeviceInit(DeviceObject, &FsvolDeviceExtension->VolumeParams);
@@ -337,6 +337,11 @@ static NTSTATUS FspFsvolDeviceInit(PDEVICE_OBJECT DeviceObject)
                 return Result;
             FsvolDeviceExtension->InitDoneFsext = 1;
         }
+        else
+        {
+            ASSERT(!NT_SUCCESS(Result));
+            return Result;
+        }
     }
 
     /* is there a virtual disk? */
@@ -519,7 +524,7 @@ static VOID FspFsvolDeviceFini(PDEVICE_OBJECT DeviceObject)
     if (FsvolDeviceExtension->InitDoneFsext)
     {
         FSP_FSEXT_PROVIDER *Provider = FspFsextProvider(
-            FsvolDeviceExtension->VolumeParams.FsextControlCode);
+            FsvolDeviceExtension->VolumeParams.FsextControlCode, 0);
         if (0 != Provider)
             Provider->DeviceFini(DeviceObject);
     }
@@ -573,7 +578,7 @@ static VOID FspFsvolDeviceExpirationRoutine(PVOID Context)
     if (0 != FsvolDeviceExtension->VolumeParams.FsextControlCode)
     {
         FSP_FSEXT_PROVIDER *Provider = FspFsextProvider(
-            FsvolDeviceExtension->VolumeParams.FsextControlCode);
+            FsvolDeviceExtension->VolumeParams.FsextControlCode, 0);
         if (0 != Provider)
             Provider->DeviceExpirationRoutine(DeviceObject, InterruptTime);
     }

src/sys/driver.h

@@ -37,6 +37,12 @@
 
 #define DRIVER_NAME                     FSP_FSCTL_DRIVER_NAME
 
+#if _WIN64
+#define FSP_REGKEY                      "\\Registry\\Machine\\Software\\WOW6432Node\\WinFsp"
+#else
+#define FSP_REGKEY                      "\\Registry\\Machine\\Software\\WinFsp"
+#endif
+
 /* IoCreateDeviceSecure default SDDL's */
 #define FSP_FSCTL_DEVICE_SDDL           "D:P(A;;GA;;;SY)(A;;GA;;;BA)(A;;GR;;;WD)"
     /* System:GENERIC_ALL, Administrators:GENERIC_ALL, World:GENERIC_READ */
@@ -1182,7 +1188,7 @@ VOID FspDeviceGlobalUnlock(VOID)
     //    STATUS_VOLUME_DISMOUNTED : STATUS_DEVICE_NOT_CONNECTED)
 
 /* fsext */
-FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode);
+FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode, PNTSTATUS PLoadResult);
 
 /* process buffers conditional usage */
 static inline

src/sys/fsctl.c

@@ -113,7 +113,7 @@ static NTSTATUS FspFsctlFileSystemControl(
                     FsvolDeviceExtension->VolumeParams.FsextControlCode)
                 {
                     FSP_FSEXT_PROVIDER *Provider = FspFsextProvider(
-                        FsvolDeviceExtension->VolumeParams.FsextControlCode);
+                        FsvolDeviceExtension->VolumeParams.FsextControlCode, 0);
                     if (0 != Provider)
                         Result = Provider->DeviceTransact(FsvolDeviceObject, Irp);
                 }

src/sys/fsext.c

@@ -25,7 +25,7 @@
 static KSPIN_LOCK FsextSpinLock = 0;
 FSP_FSEXT_PROVIDER *FsextProvider;
 
-FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode)
+FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode, PNTSTATUS PLoadResult)
 {
     FSP_FSEXT_PROVIDER *Provider;
     KIRQL Irql;
@@ -34,6 +34,61 @@ FSP_FSEXT_PROVIDER *FspFsextProvider(UINT32 ControlCode)
     Provider = FsextProvider;
     KeReleaseSpinLock(&FsextSpinLock, Irql);
 
+    if (0 != PLoadResult)
+    {
+        if (0 == Provider)
+        {
+            WCHAR Buf[64 + 256];
+            UNICODE_STRING Path;
+            UNICODE_STRING Name;
+            union
+            {
+                KEY_VALUE_PARTIAL_INFORMATION V;
+                UINT8 B[FIELD_OFFSET(KEY_VALUE_PARTIAL_INFORMATION, Data) + 256];
+            } Value;
+            ULONG Length;
+            NTSTATUS Result;
+
+            RtlInitUnicodeString(&Path, L"" FSP_REGKEY "\\Fsext");
+            RtlInitEmptyUnicodeString(&Name, Buf, sizeof Buf);
+            Result = RtlUnicodeStringPrintf(&Name, L"%08x", ControlCode);
+            ASSERT(NT_SUCCESS(Result));
+            Length = sizeof Value;
+            Result = FspRegistryGetValue(&Path, &Name, &Value.V, &Length);
+            if (STATUS_SUCCESS != Result/*!NT_SUCCESS*/)
+            {
+                if (STATUS_BUFFER_OVERFLOW == Result)
+                    Result = STATUS_BUFFER_TOO_SMALL;
+
+                *PLoadResult = Result;
+                return 0;
+            }
+            if (REG_SZ != Value.V.Type)
+            {
+                *PLoadResult = STATUS_OBJECT_NAME_NOT_FOUND;
+                return 0;
+            }
+
+            RtlInitEmptyUnicodeString(&Path, Buf, sizeof Buf);
+            Result = RtlUnicodeStringPrintf(&Path,
+                L"\\Registry\\Machine\\System\\CurrentControlSet\\Services\\%s", Value.V.Data);
+            ASSERT(NT_SUCCESS(Result));
+
+            Result = ZwLoadDriver(&Path);
+            if (!NT_SUCCESS(Result) && STATUS_IMAGE_ALREADY_LOADED != Result)
+            {
+                *PLoadResult = Result;
+                return 0;
+            }
+
+            KeAcquireSpinLock(&FsextSpinLock, &Irql);
+            Provider = FsextProvider;
+            KeReleaseSpinLock(&FsextSpinLock, Irql);
+        }
+
+        *PLoadResult = 0 != Provider ? STATUS_SUCCESS : STATUS_OBJECT_NAME_NOT_FOUND;
+    }
+
     return Provider;
 }
 
@@ -43,14 +98,18 @@ NTSTATUS FspFsextProviderRegister(FSP_FSEXT_PROVIDER *Provider)
     KIRQL Irql;
 
     KeAcquireSpinLock(&FsextSpinLock, &Irql);
+
     if (0 != FsextProvider)
     {
         Result = STATUS_TOO_LATE;
         goto exit;
     }
+
     Provider->DeviceExtensionOffset = FIELD_OFFSET(FSP_FSVOL_DEVICE_EXTENSION, FsextData);
     FsextProvider = Provider;
+
     Result = STATUS_SUCCESS;
+
 exit:
     KeReleaseSpinLock(&FsextSpinLock, Irql);