sys: IRP_MJ_CREATE: allow simple volume opens

src/sys/cleanup.c

@@ -48,6 +48,10 @@ static NTSTATUS FspFsvolCleanup(
 {
     PAGED_CODE();
 
+    /* is this a valid FileObject? */
+    if (!FspFileContextIsValid(IrpSp->FileObject->FsContext))
+        return STATUS_SUCCESS;
+
     NTSTATUS Result;
     FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension = FspFsvolDeviceExtension(DeviceObject);
     PFILE_OBJECT FileObject = IrpSp->FileObject;
@@ -92,7 +96,8 @@ static NTSTATUS FspFsvolCleanup(
 
     PDEVICE_OBJECT FsvrtDeviceObject = FsvolDeviceExtension->FsvrtDeviceObject;
     if (!FspDeviceRetain(FsvrtDeviceObject))
-        return STATUS_CANCELLED;
+        /* IRP_MJ_CLEANUP cannot really fail :-\ */
+        return STATUS_SUCCESS;
 
     try
     {

src/sys/close.c

@@ -48,6 +48,10 @@ static NTSTATUS FspFsvolClose(
 {
     PAGED_CODE();
 
+    /* is this a valid FileObject? */
+    if (!FspFileContextIsValid(IrpSp->FileObject->FsContext))
+        return STATUS_SUCCESS;
+
     NTSTATUS Result;
     FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension = FspFsvolDeviceExtension(DeviceObject);
     PFILE_OBJECT FileObject = IrpSp->FileObject;
@@ -60,7 +64,8 @@ static NTSTATUS FspFsvolClose(
 
     PDEVICE_OBJECT FsvrtDeviceObject = FsvolDeviceExtension->FsvrtDeviceObject;
     if (!FspDeviceRetain(FsvrtDeviceObject))
-        return STATUS_CANCELLED;
+        /* IRP_MJ_CLOSE cannot really fail :-\ */
+        return STATUS_SUCCESS;
 
     try
     {

src/sys/create.c

@@ -61,6 +61,15 @@ static NTSTATUS FspFsvolCreate(
 {
     PAGED_CODE();
 
+    /* open the volume object? */
+    if (0 == IrpSp->FileObject->FileName.Length &&
+        (0 == IrpSp->FileObject->RelatedFileObject ||
+            0 == IrpSp->FileObject->RelatedFileObject->FsContext))
+    {
+        Irp->IoStatus.Information = FILE_OPENED;
+        return STATUS_SUCCESS;
+    }
+
     NTSTATUS Result;
     FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension = FspFsvolDeviceExtension(DeviceObject);
 
@@ -95,13 +104,6 @@ static NTSTATUS FspFsvolCreate(
         FSP_FILE_CONTEXT *FsContext = 0;
         FSP_FSCTL_TRANSACT_REQ *Request;
 
-        /* cannot open the volume object */
-        if (0 == RelatedFileObject && 0 == FileName.Length)
-        {
-            Result = STATUS_ACCESS_DENIED;
-            goto exit;
-        }
-
         /* cannot open a paging file */
         if (FlagOn(Flags, SL_OPEN_PAGING_FILE))
         {
@@ -195,6 +197,15 @@ static NTSTATUS FspFsvolCreate(
         /* is this a relative or absolute open? */
         if (0 != RelatedFileObject)
         {
+            FSP_FILE_CONTEXT *RelatedFsContext = RelatedFileObject->FsContext;
+
+            /* is this a valid RelatedFileObject? */
+            if (!FspFileContextIsValid(RelatedFsContext))
+            {
+                Result = STATUS_OBJECT_PATH_NOT_FOUND;
+                goto exit;
+            }
+
             /* must be a relative path */
             if (sizeof(WCHAR) <= FileName.Length && L'\\' == FileName.Buffer[0])
             {
@@ -202,9 +213,6 @@ static NTSTATUS FspFsvolCreate(
                 goto exit;
             }
 
-            FSP_FILE_CONTEXT *RelatedFsContext = RelatedFileObject->FsContext;
-            ASSERT(0 != RelatedFsContext);
-
             /* cannot FILE_DELETE_ON_CLOSE on the root directory */
             if (sizeof(WCHAR) == RelatedFsContext->FileName.Length &&
                 0 == FileName.Length &&
@@ -605,11 +613,6 @@ VOID FspFsvolCreateComplete(
      * Looks like SUCCESS!
      */
 
-     /* record the user-mode file system contexts */
-    FsContext->UserContext = Response->Rsp.Create.Opened.UserContext;
-    FileObject->FsContext = FsContext;
-    FileObject->FsContext2 = (PVOID)(UINT_PTR)Response->Rsp.Create.Opened.UserContext2;
-
     /* did an FsContext with the same UserContext already exist? */
     if (!Inserted)
         /* delete the newly created FsContext as it is not being used */
@@ -618,6 +621,11 @@ VOID FspFsvolCreateComplete(
     /* disassociate our FsContext from the Request */
     FspIopRequestContext(Request, RequestFsContext) = 0;
 
+    /* record the user-mode file system contexts */
+    FsContext->UserContext = Response->Rsp.Create.Opened.UserContext;
+    FileObject->FsContext = FsContext;
+    FileObject->FsContext2 = (PVOID)(UINT_PTR)Response->Rsp.Create.Opened.UserContext2;
+
     /* finish seting up the FileObject */
     FileObject->Vpb = FsvrtDeviceObject->Vpb;
 

src/sys/driver.h

@@ -379,6 +379,14 @@ VOID FspDeviceDeleteList(
 VOID FspDeviceDeleteAll(VOID);
 
 /* file objects */
+#define FspFileContextKind(FsContext)   \
+    (((FSP_FILE_CONTEXT *)FsContext)->Header.NodeTypeCode)
+#define FspFileContextIsValid(FsContext)\
+    (0 != (FsContext) && FspFileContextFileKind == ((FSP_FILE_CONTEXT *)FsContext)->Header.NodeTypeCode)
+enum
+{
+    FspFileContextFileKind = 'BZ',
+};
 typedef struct
 {
     ERESOURCE Resource;

src/sys/fileobj.c

@@ -39,7 +39,7 @@ NTSTATUS FspFileContextCreate(PDEVICE_OBJECT DeviceObject,
     ExInitializeFastMutex(&NonPaged->HeaderFastMutex);
 
     RtlZeroMemory(FsContext, sizeof *FsContext + ExtraSize);
-    FsContext->Header.NodeTypeCode = 'F';
+    FsContext->Header.NodeTypeCode = FspFileContextFileKind;
     FsContext->Header.NodeByteSize = sizeof *FsContext;
     FsContext->Header.IsFastIoPossible = FastIoIsQuestionable;
     FsContext->Header.Resource = &NonPaged->Resource;