[ovs-dev] [PATCH] RFC datapath-windows: Create com device only when extension is enabled

[Shashank Ram]

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From: ovs-dev-bounces at openvswitch.org <ovs-dev-bounces at openvswitch.org> on behalf of Alin Gabriel Serdean <aserdean at ovn.org>
Sent: Tuesday, April 3, 2018 8:08 AM
To: dev at openvswitch.org
Cc: Alin Gabriel Serdean
Subject: [ovs-dev] [PATCH] RFC datapath-windows: Create com device only when    extension is enabled

Until now the communication device between the kernel and userspace
is created when the network driver is installed.

Since we only do processing if the Hyper-V vSwitch extension is enabled by
the user, it makes more sense to move the device creation only when that is true.

Signed-off-by: Alin Gabriel Serdean <aserdean at ovn.org>
---
 datapath-windows/ovsext/Datapath.c |  2 +-
 datapath-windows/ovsext/Driver.c   | 10 ----------
 datapath-windows/ovsext/Switch.c   |  7 +++++++
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/datapath-windows/ovsext/Datapath.c b/datapath-windows/ovsext/Datapath.c
index 34ef2b40a..264cfd3a0 100644
--- a/datapath-windows/ovsext/Datapath.c
+++ b/datapath-windows/ovsext/Datapath.c
@@ -352,7 +352,7 @@ _Dispatch_type_(IRP_MJ_DEVICE_CONTROL)
 DRIVER_DISPATCH OvsDeviceControl;

 #ifdef ALLOC_PRAGMA
-#pragma alloc_text(INIT, OvsCreateDeviceObject)
+#pragma alloc_text(PAGE, OvsCreateDeviceObject)
 #pragma alloc_text(PAGE, OvsOpenCloseDevice)
 #pragma alloc_text(PAGE, OvsCleanupDevice)
 #pragma alloc_text(PAGE, OvsDeviceControl)
diff --git a/datapath-windows/ovsext/Driver.c b/datapath-windows/ovsext/Driver.c
index 50c9614e4..39e50c34b 100644
--- a/datapath-windows/ovsext/Driver.c
+++ b/datapath-windows/ovsext/Driver.c
@@ -152,14 +152,6 @@ DriverEntry(PDRIVER_OBJECT driverObject,
         goto cleanup;
     }

-    /* Create the communication channel for userspace. */
-    status = OvsCreateDeviceObject(gOvsExtDriverHandle);
-    if (status != NDIS_STATUS_SUCCESS) {
-        NdisFDeregisterFilterDriver(gOvsExtDriverHandle);
-        gOvsExtDriverHandle = NULL;
-        goto cleanup;
-    }
-
 cleanup:
     if (status != NDIS_STATUS_SUCCESS){
         OvsCleanup();
@@ -179,8 +171,6 @@ OvsExtUnload(struct _DRIVER_OBJECT *driverObject)
 {
     UNREFERENCED_PARAMETER(driverObject);

-    OvsDeleteDeviceObject();
-
     NdisFDeregisterFilterDriver(gOvsExtDriverHandle);

     /* Release driver associated data structures. */
diff --git a/datapath-windows/ovsext/Switch.c b/datapath-windows/ovsext/Switch.c
index 1ac4fa77c..81b897ffe 100644
--- a/datapath-windows/ovsext/Switch.c
+++ b/datapath-windows/ovsext/Switch.c
@@ -73,6 +73,12 @@ OvsExtAttach(NDIS_HANDLE ndisFilterHandle,
     NDIS_STATUS status = NDIS_STATUS_FAILURE;
     NDIS_FILTER_ATTRIBUTES ovsExtAttributes;
     POVS_SWITCH_CONTEXT switchContext = NULL;
+    /* Create the communication channel for userspace. */
+    status = OvsCreateDeviceObject(gOvsExtDriverHandle);
+    if (status != NDIS_STATUS_SUCCESS) {
+        status = NDIS_STATUS_INVALID_PARAMETER;

Why change the status? It would be better to retain the status to whatever is returned by OvsCreateDeviceObject()

+        goto cleanup;
+    }

     UNREFERENCED_PARAMETER(filterDriverContext);

@@ -266,6 +272,7 @@ OvsExtDetach(NDIS_HANDLE filterModuleContext)
     while(switchContext->pendingOidCount > 0) {
         NdisMSleep(1000);
     }
+    OvsDeleteDeviceObject();
     OvsDeleteSwitch(switchContext);
     OvsCleanupIpHelper();
     OvsCleanupSttDefragmentation();
--
2.16.1.windows.1

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