Re: [dm-devel] DM kernel interface

[Mikulas Patocka <mpatocka redhat com>]

On Thu, 15 Jan 2009, Allen Jack wrote:

> I have used the ioctl interface to create dm objects and get information 
> about dm objects from a user space application, and am familiar with it.  
> I am now required to get the object information from kernel space, and 
> was wondering what interface is available to do that directly.
> 
> Is there a direct device mapper interface in kernel space that I can use 
> to get the object information from?  For example, I need to see the 
> target mappings within a linear object.
> 
> Allen Jack
> Sr. Software Engineer
> ajack novell com
> (801) 861-5923
> Novell, Inc.
> Making IT Work As One
> www.novell.com

Hi

You can call the same ioctls from kernel space as well, see ioctl_by_bdev.

Calling device mapper functions defined in <linux/device-mapper.h> 
directly is discouraged if you are not developing dm target driver.

Mikulas