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

[Paolo Bonzini]

On 02/11/2015 16:05, Mike Snitzer wrote:
> > In any case, if we don't start path activation we should return
> > ENOTCONN, not ENOTTY.
> 
> Currently, if we don't start path activation we're returning EIO.
> ENOTCONN is used for when we do start path activation (and ENOTCONN is
> the means for DM core to retry)
> 
> We _could_ change the ENOTCONN to be EAGAIN and EIO to ENOTCONN...

This makes sense... though of course testing the impact of this on
userspace is going to be hard. :(  Chances are that userspace is not
expecting EAGAIN either.

Even if they did, how would someone know that they can now retry the
ioctl after getting EAGAIN?  Should they just do it in a loop?

Paolo