Re: [PATCH] nvme: reject completions for requests that are not in flight

[Keith Busch <kbusch@kernel.org>]

On Tue, Nov 03, 2026 at 04:54:27PM -0300, Mauricio Faria de Oliveira wrote:
> For the former question, I'd imagine other block drivers might be
> subject to a similar issue, under incorrect completions, and can take a
> look at this later. I'd appreciate feedback on the points above before
> trying to address it generically in the block layer, if at all possible.

Here's my real concern: the proposal is a race. Another CPU can change
the request state to in-flight, and this code will declare it complete
before the hardware even saw it. It's a silent data corruption problem
that we can't fix because it is impossible to tell the difference
between a bogus and a legit completion at that point. This kind of
hardware shouldn't be allowed to exist as it can't be used successfully
when it behaves this way.