Re: [PATCH 5/7] FUSE: implement ioctl support

[Tejun Heo <tj@kernel.org>]

Eric W. Biederman wrote:
> I really think that if an ioctl is passing through the kernel we
> should know how to parse and understand it's options.  Otherwise
> we won't have the option of doing backwards compatibility when something
> changes, like we can with the 32->64bit ioctls.

There's no reason 32->64bit can't be handled in userland?  What's the
difference?

> That seems to imply that you need a stub in the kernel to handle 
> really weird ioctls.
> 
> The upside is that because you know what the inputs and outputs are
> and where the inputs and output are you can support that ioctl well
> into the future, and you can do it with an unprivileged file
> system server.

Well, kernel stub kind of beats a lot of benefits of FUSE - no
specific kernel dependencies, easy development and distribution,
etc...

Thanks.

-- 
tejun