Re: WARN_ON_ONCE(1) in iomap_dio_actor()

[Christoph Hellwig]

On Thu, Aug 13, 2020 at 03:52:13AM -0400, Qian Cai wrote:
> > No sane application would ever do this, it's behaviour as expected,
> > so I don't think there's anything to care about here.
> 
> It looks me the kernel warning is trivial to trigger by an non-root user. Shouldn???t we worry a bit because this could be a DoS for systems which set panic_on_warn?

Yes, we should trigger a WARN_ON on user behavior.  a
pr_info_ratelimited + tracepoint and a good comment is probably the
better solution.