# Re: \[PATCH 2/2\] block: create ioctl to discard-or-zeroout a range of blocks

- From: Linus Torvalds \<torvalds@linux-foundation.org\>
- Date: 2016-03-11 18:25:31 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2016/03/105919
- Thread: https://ratatoskr.run/linux-api/2016/03/105935/t.md

```text
On Fri, Mar 11, 2016 at 9:30 AM, Andy Lutomirski [ref] wrote:
>
> What if we had an ioctl to do these data-leaking operations that took,
> as an extra parameter, an fd to the block device node.  They allow
> access if the fd points to the right inode and has FMODE_READ (and LSM
> checks say it's okay).  Sure, it's awkward, but it's much safer.

That sounds absolutely horrible.

I'd *much* prefer the suggestion from Alan to simply have a mount-time
option to enable it. That way, you will never get any surprises, and
no "subtle new behavior for somebody who set their system up in a way
that doesn't allow for this".

So you'd have to explicitly say "my setup is ok with hole punching".

                Linus
```