Re: [PATCH][RFC/v1][9/12] Add InfiniBand userspace MAD support

[Greg KH <greg@kroah.com>]

On Mon, Nov 22, 2004 at 03:05:40PM -0800, Roland Dreier wrote:
>     Greg> You are letting any user, with any privilege register or
>     Greg> unregister an "agent"?
> 
> They have to be able to open the device node.  We could add a check
> that they have it open for writing but there's not really much point
> in opening this device read-only.

Ok, I remember this conversation a while ago.  We discussed this same
thing a number of months back on the openib mailing list.  Nevermind :)

>     Greg> Also, these "agents" seem to be a type of filter, right?  Is
>     Greg> there no other way to implement this than an ioctl?
> 
> ioctl seems to be the least bad way to me.  This really feels like a
> legitimate use of ioctl to me -- we use read/write to handle passing
> data through our file descriptor, and ioctl for control of the
> properties of the descriptor.
> 
> What would you suggest as an ioctl replacement?

I really can't think of anything else.  It just will require a _lot_ of
vigilant attention to prevent people from adding other ioctls to this
one, right?

Do you have other ioctls planned for this same interface for stage 2 and
future stages of ib implementation for Linux?

thanks,

greg k-h