Re: 4.9.0 regression in pipe-backed iov_iter with systemd-nspawn

[Linus Torvalds]

On Thu, Jan 12, 2017 at 3:02 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> Looking at the callers of "do_splice_to()", we already have the
> wait_for_space() in do_splice(), but we do *not* have it in the
> do_splice_from() case when both the input and output file descriptors
> are pipes.

Bah. That case doesn't even trigger the new code. I was lazy with my
grep. The two cases are "do_splice()" (which does have the
wait-for-space) and splice_direct_to_actor(). And
splice_direct_to_actor() shouldn't even need it, should it?

So ignore that. But I think there is something about the EAGAIN.

                  Linus