block dangerous passthrough operation

[Keith Busch]

On Mon, Nov 21, 2022 at 08:46:47AM +0100, Christoph Hellwig wrote:
> On Wed, Nov 16, 2022 at 08:49:42PM -0700, Jens Axboe wrote:
> > Honestly, I think this is a mess, and it's exactly why I didn't like
> > going down this path to begin with. I'm assuming that last 'now' above
> > should be a 'not'? This approach is not going to be maintainable.
> 
> What else can be we?  Allow people to put the driver into all kinds of
> weird states without us even knowing and just deal with it?

It's not like just anyone can do this kind of craziness. It's like a
soft equivalent of pulling a cable. There are usually access
restrictions for untrusted people.