From 2e828da9a292d48a891a534a5180ee355205979b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herv=C3=A9=20Poussineau?= <hpoussin@reactos.org>
Date: Thu, 19 May 2005 22:02:34 +0000
Subject: [PATCH] Don't create a new DriverObject if one is already existing

svn path=/trunk/; revision=15414
---
 reactos/ntoskrnl/include/internal/io.h |  6 ++
 reactos/ntoskrnl/io/driver.c           | 79 ++++++++++++++++++++------
 reactos/ntoskrnl/io/pnpmgr.c           | 11 ++--
 3 files changed, 72 insertions(+), 24 deletions(-)

diff --git a/reactos/ntoskrnl/include/internal/io.h b/reactos/ntoskrnl/include/internal/io.h
index c5bde62b364..0b40de614dc 100644
--- a/reactos/ntoskrnl/include/internal/io.h
+++ b/reactos/ntoskrnl/include/internal/io.h
@@ -517,6 +517,12 @@ IopCreateDriverObject(
    PVOID DriverImageStart,
    ULONG DriverImageSize);
 
+NTSTATUS FASTCALL
+IopGetDriverObject(
+   PDRIVER_OBJECT *DriverObject,
+   PUNICODE_STRING ServiceName,
+   BOOLEAN FileSystem);
+
 NTSTATUS FASTCALL
 IopLoadServiceModule(
    IN PUNICODE_STRING ServiceName,
diff --git a/reactos/ntoskrnl/io/driver.c b/reactos/ntoskrnl/io/driver.c
index 1fed5a0cdfc..8164b4e4c6e 100644
--- a/reactos/ntoskrnl/io/driver.c
+++ b/reactos/ntoskrnl/io/driver.c
@@ -151,6 +151,64 @@ IopDeleteDriver(PVOID ObjectBody)
    KfLowerIrql(OldIrql);
 }
 
+NTSTATUS FASTCALL
+IopGetDriverObject(
+   PDRIVER_OBJECT *DriverObject,
+   PUNICODE_STRING ServiceName,
+   BOOLEAN FileSystem)
+{
+   PDRIVER_OBJECT Object;
+   WCHAR NameBuffer[MAX_PATH];
+   UNICODE_STRING DriverName;
+   OBJECT_ATTRIBUTES ObjectAttributes;
+   NTSTATUS Status;
+
+   DPRINT("IopOpenDriverObject(%p '%wZ' %x)\n",
+      DriverObject, ServiceName, FileSystem);
+
+   *DriverObject = NULL;
+
+   /* Create ModuleName string */
+   if (ServiceName == NULL || ServiceName->Buffer == NULL)
+      /* We don't know which DriverObject we have to open */
+      return STATUS_INVALID_PARAMETER_2;
+
+   if (FileSystem == TRUE)
+      wcscpy(NameBuffer, FILESYSTEM_ROOT_NAME);
+   else
+      wcscpy(NameBuffer, DRIVER_ROOT_NAME);
+   wcscat(NameBuffer, ServiceName->Buffer);
+
+   RtlInitUnicodeString(&DriverName, NameBuffer);
+   DPRINT("Driver name: '%wZ'\n", &DriverName);
+
+   /* Initialize ObjectAttributes for driver object */
+   InitializeObjectAttributes(
+      &ObjectAttributes,
+      &DriverName,
+      OBJ_OPENIF | OBJ_KERNEL_HANDLE,
+      NULL,
+      NULL);
+
+   /* Open driver object */
+   Status = ObReferenceObjectByName(
+      &DriverName,
+      0, /* Attributes */
+      NULL, /* PassedAccessState */
+      0, /* DesiredAccess */
+      IoDriverObjectType,
+      KernelMode,
+      NULL, /* ParseContext */
+      (PVOID*)&Object);
+
+   if (!NT_SUCCESS(Status))
+      return Status;
+
+   *DriverObject = Object;
+
+   return STATUS_SUCCESS;
+}
+
 NTSTATUS FASTCALL
 IopCreateDriverObject(
    PDRIVER_OBJECT *DriverObject,
@@ -229,18 +287,8 @@ IopCreateDriverObject(
    {
       return Status;
    }  
-   
-   /* This function shouldn't be called twice for the same driver anyways..why is it? */
-#if 0
-   if (Status == STATUS_OBJECT_EXISTS)
-   {
-      /* The driver object already exists, so it is already
-       * initialized. Don't initialize it once more. */
-      *DriverObject = Object;
-      return STATUS_SUCCESS;
-   }
-#endif
-     /* Create driver extension */
+
+   /* Create driver extension */
    Object->DriverExtension = (PDRIVER_EXTENSION)
       ExAllocatePoolWithTag(
          NonPagedPool,
@@ -652,13 +700,10 @@ IopAttachFilterDriversCallback(
       else
       {
          /* get existing DriverObject pointer */
-         Status = IopCreateDriverObject(
+         Status = IopGetDriverObject(
             &DriverObject,
             &ServiceName,
-            OBJ_OPENIF,
-            FALSE,
-            ModuleObject->Base,
-            ModuleObject->Length);
+            FALSE);
          if (!NT_SUCCESS(Status))
             continue;
       }
diff --git a/reactos/ntoskrnl/io/pnpmgr.c b/reactos/ntoskrnl/io/pnpmgr.c
index 60e5b137677..b89b4f5bcff 100644
--- a/reactos/ntoskrnl/io/pnpmgr.c
+++ b/reactos/ntoskrnl/io/pnpmgr.c
@@ -1668,13 +1668,10 @@ IopActionInitChildServices(
          else
          {
             /* get existing DriverObject pointer */
-            Status = IopCreateDriverObject(
-            	&DriverObject,
-            	&DeviceNode->ServiceName,
-            	OBJ_OPENIF,
-            	FALSE,
-            	ModuleObject->Base,
-            	ModuleObject->Length);
+            Status = IopGetDriverObject(
+               &DriverObject,
+               &DeviceNode->ServiceName,
+               FALSE);
          }
          if (NT_SUCCESS(Status))
          {