Disk filter driver

Hi all,

I want to write upper disk filter driver targetting a particular volume.
How to attach a disk filter driver to a specific drive or volume only??
How to capture Read/Write requests for files only i.e. how to check whether
a particular Read/Write call
is for normal file(i.e. I don’t want to handle file’s metadata related
calls)?
How can I get file information in disk filter driver?


Kapil Bhadke

> I want to write upper disk filter driver targetting a particular volume.

How to attach a disk filter driver to a specific drive or?volume?only??
How to capture Read/Write requests for files only i.e. how to check whether
a particular Read/Write call
is for normal file(i.e. I don’t want to handle file’s metadata related
calls)?
How can I get file information in disk filter driver?

If you want to trap file read/writes then use file system filter driver.
Volume filter driver will not get file related info, they will be
getting request for sector read/write.

-santosh k

>

If you want to trap file read/writes then use file system filter driver.
Volume filter driver will not get file related info, they will be
getting request for sector read/write.

Thats perfectly fine. But what I want is read/write request in terms of
sector blocks along with file information for which that call is initiated.
Is there any way that I could pass file information from minifilter driver
to disk filter driver??
i.e. anyhow create 1 data structure and minifilter will store needed
information in that data structure and disk filter then retrieve it??


Kapil Bhadke

Why do you want this? I.E. What is your base goal here?

Don Burn (MVP, Windows DKD)
Windows Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr

“kapil bhadke” wrote in message
news:xxxxx@ntdev:

> >
> > If you want to trap file read/writes then use file system filter driver.
> > Volume filter driver will not get file related info, they will be
> > getting request for sector read/write.
> >
> > Thats perfectly fine. But what I want is read/write request in terms of
> sector blocks along with file information for which that call is initiated.
> Is there any way that I could pass file information from minifilter driver
> to disk filter driver??
> i.e. anyhow create 1 data structure and minifilter will store needed
> information in that data structure and disk filter then retrieve it??
>
>
> –
> Kapil Bhadke

Why do you want this? I.E. What is your base goal here?

My ultimate goal is to write a driver for encryption/decryption same as EFS
but with some extra features added.
So if I write file system filter driver then I am facing following problems

  1. Read/Write requests are not in terms of disk blocks which I needed
  2. If I go on writing 1-1 byte in any file then I will have to handle these
    requests for each write request above the file system which I could have
    eliminated if I write disk filter driver.


Kapil Bhadke

It is easy to distinguish the non-cached writes (i.e. block writes) in a
mini-filter. Of course this means the data in cache is unencrypted.
This really should move to NTFSD since it requires a file system.

Don Burn (MVP, Windows DKD)
Windows Filesystem and Driver Consulting
Website: http://www.windrvr.com
Blog: http://msmvps.com/blogs/WinDrvr

“kapil bhadke” wrote in message
news:xxxxx@ntdev:

> Why do you want this? I.E. What is your base goal here?
> >
>
> My ultimate goal is to write a driver for encryption/decryption same as EFS
> but with some extra features added.
> So if I write file system filter driver then I am facing following problems
> 1. Read/Write requests are not in terms of disk blocks which I needed
> 2. If I go on writing 1-1 byte in any file then I will have to handle these
> requests for each write request above the file system which I could have
> eliminated if I write disk filter driver.
>
>
> –
> Kapil Bhadke