Re: Why ext4 encryption is disabled in our linux-libre-4.8 config

[ludo@gnu.org (Ludovic Courtès)]

Hi Mark!

Mark H Weaver <mhw@netris.org> skribis:

> One possible solution would be to enhance 'flat-linux-module-directory'
> to silently ignore missing modules when the needed functionality is
> built-in to the kernel, as indicated by the presence of
> "CONFIG_CRYPTO_XTS=y" in #$linux/.config.

That sounds like a good idea.  David hit a similar problem with commit
50dbc03647170fded9e0bca0cc4b7e1614aa38db.

> One caveat with this approach is that I don't know how to map module
> names to Kconfig flags.  Does anyone know how?  If needed, I suppose we
> could lazily accumulate our own subset of this mapping, starting with
> only the modules used by our initrd by default.  Alternatively, we could
> change our lists of module names into lists of (module-name config-flag)
> pairs.

I suspect there’s no systematic way to map option names to module names.
We may have to maintain our own list of option/module pairs, but that
doesn’t sound unreasonable.

Cheers,
Ludo’.