Magic symlinks redux

[Andrey V. Elsukov]

Ivan Voras wrote:
> Firstly, it might be useless for your purpose but there are others.
> 
> If you read the NetBSD's documentation about magiclinks, you'll see
> this set of supported variables:

Originally I wanted to implement 4 layers:

1. System-wide (jail-wide)(global for all jails etc). Only root can
set variables in this layer.

2. Kernel-wide. Variables in this layer can be set from KLD's.
Some KPI needed for setting these variables (also all netbsd-like
variables can be implemented in this layer). Superuser can override
these variables via system-wide layer.

3. Per-user.

4. Per-process.

-- 
WBR, Andrey V. Elsukov