mrg@eterna.com.au said:
> it seems that we need some new preprocessor symbol to deal with this,
> such as `_KERNEL_FROM_USERLAND' which basically means to not include
> opt_xxx.h files, and any userland code that wants to #define _KERNEL
> must also define this.

I'd prefer it the other way: define a cpp symbol like
"__EXPOSE_UFS_INTERNALS" from userland instead of _KERNEL, so we
can control what gets exported from the system headers.
(see sys/pool.h)

btw, I don't like the inclusion of "opt_*.h" headers from include
files much (unless the definition is explicitely needed within
that include file). Causes needless dependencies, and makes it
non-obvious whether a .c file really includes the opt_ headers
it needs.

best regards
Matthias