Re: [PATCH 2/3] mm/filemap: initiate readahead even if IOCB_NOWAIT is set for the I/O

[Linus Torvalds]

On Thu, Jan 31, 2019 at 9:16 PM Dave Chinner <david@xxxxxxxxxxxxx> wrote:
>
> You are conflating "best effort non-blocking operation" with
> "atomic guarantee".  RWF_NOWAIT/IOCB_NOWAIT is the
> former, not the latter.

Right.

That's my *point*, Dave.

It's not 'atomic guarantee", and never will be. We are in 100%
agreement. That's what I _said_.

And part of "best effort" is very much "not a security information leak".

I really don't see why you are so argumentative.

As I mentioned earlier in the thread, it's actually quite possible
that users will actually find that starting read-ahead is a *good*
thing, Dave.

Even - in fact *particularly* - the user you brought up: samba using
RWF_NOWAIT to try to do things synchronously quickly.

So Dave, why are you being so negative?

             Linus