On Tue, 29 Jul 2025 at 00:49, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>
> I don't think overrides are intentional here. The problem is that
> Christian asked for the flexible size growing decoding here, which
> makes it impossible to use the simple and proven ioctl dispatch by
> just using another case statement in the switch.
Right. Which is why I put it in the default: branch.
IOW, just handle the important real and normal cases first - the ones
that *can* be handled with simple switch statements.
So putting it at the *top*, and then saying "if it returns this
special error code that isn't standardized we do the normal ones" is
wrong.
It's wrong because we literally have over half a century of confusion
about error codes in this area, predating Linux.
And it's also wrong because that new ioctl simply shouldn't be
prioritized over existing ones.
So I'm just saying "don't do that then".
Linus
