u-codalist-z149_at_aetey.se writes:

> On Fri, Aug 01, 2014 at 01:54:06PM -0400, Jan Harkes wrote:
>> The kernel part of the pioctl interface is tiny. text is 163 bytes and
>> data is 200 bytes, it just is a copy-in-copy-out in the kernel module.
>> But as it does that it also tags the request with the actual uid of the
>> user making the request.
>
>> Moving to FUSE would be a much better approach if you want to get rid of
>> kernel complexity. Patches are welcome.
>
> Does FUSE provide a suitable counterpart to the pioctl?

Stepping back, what is pioctl used for?  Is this the interface from the
cfs command to venus?  It does seem like this should go through the
kernel so that requests are tagged with the credentials of the invoking
user as they arrive over FUSE.

It seems logically FUSE should provide something like this; these are
basically ioctl operations to the filesystem.   But it is probably
easier to make this an AF_UNIX socket.