Filtering USB storage data in kernel module

[Greg KH]

On Thu, Nov 17, 2011 at 02:15:35PM +0530, Abhijit Pawar wrote:
> Hi All,
> I need to filter  the data written/read to and from the USB storage 
> disk.

Why?

What are you wanting to do at "filter" time?

Why just USB disks?  What makes them special?

How are you going to determine if a disk is a USB device or not?

> Now the way USB is made known to OS is through SCSI and then 
> respective filesystem ( mostly usbfs).

Not really, usbfs is only one way, and it has nothing to do with usb
disks.

> So is there any way I can intercept this stack and have my kernel module 
> invoked so that I will get the data.

Not easily.

> I have been thinking on two approaches:
> 
> 1. Use VFS and write a proxy filesystem for USB device which will filter 
> the data.
> 2. checking SCSI and any intercepting point.

Again, what are you trying to "filter"?  That will determine where you
make changes.

thanks,

greg k-h