Configfs vs ioctl

Posted Aug 26, 2005 20:18 UTC (Fri) by giraffedata (guest, #1954)
In reply to: Configfs vs ioctl by farnz
Parent article: Configfs - an introduction

Let me emphasise again that this is only what you'd do if you'd already decided to phase out ioctl for ConfigFS.

I agree that this is the best way given that you are replacing ioctls with configfs. The obvious inference from the fact that you brought it up in response to a concern about backward compatibility is that you're saying it could be a practical way to get backward compatibilty; so I'm trying to show that it's not practical, so the backward compatibilty objection to configfs has to stand. As long as we agree there's no practical way to get backward compatibility, I have no dispute.

... one case for each ioctl goes into the library

I don't think anyone would accept that.

I don't understand the language comment; how does the kernel do it now? I thought it got a set of binary values from userspace, which it acted on.

It also gets a file descriptor, which has a lot of context with it. In particular, it tells the kernel which ioctl handler to call, and that ioctl handler knows what language (protocol) the argument is in. libc would have to be hacked really hard to have it track open file state and know which open files go with with device/file types.