微过滤器中重定向文件到不同卷的问题

在微过滤器中，将文件重定向，在前操作回调中直接修改FILEOBJECT ，意思是将老的文件名缓存释放并换成新的文件，代码如下：
FileName = &(FileObject->FileName);
FileNameBuffer = ExAllocatePool( NonPagedPool,NewFileName.MaximumLength );
if (!FileNameBuffer)
{
// Not enough resources. Complete the IRP with the appropriate status.
Data->IoStatus.Status = STATUS_INSUFFICIENT_RESOURCES;
Data->IoStatus.Information = 0;
return FLT_PREOP_SUCCESS_WITH_CALLBACK;
}
ExFreePool( FileName->Buffer );
FileName->Buffer = FileNameBuffer;
FileName->MaximumLength = NewFileName.MaximumLength;
RtlCopyUnicodeString( FileName, &NewFileName );
FltSetCallbackDataDirty(Data);
已经可以实现同卷文件重定向，但不同卷不行，按照微软文档：For example, a minifilter driver's preoperation callback routine can redirect an I/O operation to a different volume by changing the target instance for the operation. The new target instance must be an instance of the same minifilter driver at the same altitude on another volume.意思很明确，就是要将Data->Iopb->TargetInstance修改到微过滤驱动另一卷实例。我这样来实现：在全局声明一个实例变量：PFLT_INSTANCE ediskInstance，在绑定例程中将重定向的目标实例保存到这个变量中：ediskInstance = FltObjects -> Instance，最后，前操作回调中：
Data->Iopb->TargetInstance = ediskInstance;
但这样并不能将文件重定向到不同的卷，并且，在微过滤驱动退出死机。请高手来指教一下。

该问题在OSR有热烈的讨论，有些启发意义。
http://www.osronline.com/ShowThread.cfm?link=125489

最后的结论好像居然是系统Bug,请高手讨论一下：

Your code appears right. This unload hang is actually caused by a bug in Filter
Manager. When a filter changes the Data->Iopb->TargetInstance, it works
functionally correct, however the filter unload may hang. This bug will be fixed
in the next window release. You can try to request QFEs if this is critical to
your product.

Hui
File System Filter manager and Filters
Microsoft Corp.

它不说让你用QFEs吗?

用Sfilter是可以的

引用第3楼znsoft于2008-03-17 11:29发表的  :
它不说让你用QFEs吗?

QFEs = ?

quick fix engineering patches

这个问题有人解决没？

指针是不可靠的,嘿嘿......

FileName = &(FileObject->FileName);
FileNameBuffer = ExAllocatePool( NonPagedPool,NewFileName.MaximumLength );
if (!FileNameBuffer)
{
// Not enough resources. Complete the IRP with the appropriate status.
Data->IoStatus.Status = STATUS_INSUFFICIENT_RESOURCES;
Data->IoStatus.Information = 0;
return FLT_PREOP_SUCCESS_WITH_CALLBACK;
}
ExFreePool( FileName->Buffer );
FileName->Buffer = FileNameBuffer;
FileName->MaximumLength = NewFileName.MaximumLength;
RtlCopyUnicodeString( FileName, &NewFileName );
FltSetCallbackDataDirty(Data);

1. Minifilter是完全支持重定向操作的,其方法和逻辑过滤器驱动的实现方法相同!
2. 上面的代码对失败的处理明显有误"return FLT_PREOP_COMPLETE"

1. Minifilter是完全支持重定向操作的,其方法和逻辑过滤器驱动的实现方法相同!

-----------------------------------------------------------
老大还能提示一下？

http://www.osronline.com/showThread.cfm?link=98419