Re: IBM request to allow unprivledged ioctls [Was: Revert "dm mpath: fix stalls when handling invalid ioctls"]

[Paolo Bonzini <pbonzini@redhat.com>]

On 02/11/2015 14:56, Hannes Reinecke wrote:
> But then the real question remains:
> 
> What is the 'correct' behaviour for ioctls when no path retry
> is active (or when no paths are present)?
> 
> Should we start path activation?
> If so, should we wait for path activation to finish, risking udev
> killing the worker for that event (udev has a built-in timeout of
> 120 seconds, which we might easily exceed when we need to activate
> paths for large installations or slow path activation ... just
> thinking of NetApp takeover/giveback cycle)?
> If we're not waiting for path activation, where would be the point
> in starting it, seeing that we're not actually interested in the result?
> And if we shouldn't start a path activation, what is the point of
> having code for it in the first place?

That's a fair question, and it depends on what said udev worker actually
does.

In any case, if we don't start path activation we should return
ENOTCONN, not ENOTTY.

Paolo