Re: [dm-devel] [RFC] Message ioctl direct to device

[Stefan Bader <Stefan Bader de ibm com>]

>   - Why bother ioctling the dm control device when we can ioctl
>     the virtual device directly?
> 

Using the control device is usefull if you want to react on messages from
the control interface without the need to open virtual devices at that 
time
or keep filehandles open all the time.
Userspace recovery of failed multipath devices has to save as much memory
since it must pin itself into memory in order to handle low-mem 
situations.
So I would like to see a interface through the control device as well.

Stefan