Re: Passing references to kobjects between userland and kernel

From: Daniele Orlandi
Date: Mon Jun 19 2006 - 19:47:38 EST


On Saturday 17 June 2006 01:58, Greg KH wrote:
>
> Use the kobject_uevent() call from kernelspace to let userspace know
> whatever you want it to. That is what it is there for :)

kobject_uevent() is fine if I want to asynchronously notify the user space of
an event.

What I need is a synchronous bidirectional interface, e.g. I tell the kernel
"connect node X with node Y" and I get back the resulting pipeline
identifier.

> Or use configfs :)

Configfs is very interesting, it's surely well suited for several tasks I'm
doing and I will add support for it into my subsystem.

What it's missing is the ability to create non-persistent configurations,
bound to a process and disappearing along with the process that created them.

For example, my process creates pipelines between nodes using a ioctl()
interface. If the process dies unexpectedly the file descriptor is
automatically closed and I can release all the pipelines. I don't see a way I
could accomplish the same with configfs or sysfs.

OTOH, for what concerns persistent pipelines, configfs is quite good. It would
be even better if I could create links from configfs objects to sysfs
objects.

Bye,

--
Daniele "Vihai" Orlandi
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