enabling vfs plugins with libc

[Norman Feske]

Hi Stefan,

On 2/10/23 10:29, Stefan Thöni wrote:
> I'm working on enabling vfs plugins that use libc, specifically a ported 
> library. The library accesses a hardware device through a file in vfs, 
> so there is no using a minimal libc implementation as it's the libc's 
> vfs access that creates the chicken and egg problem preventing vfs 
> plugins with libc.
...
> What do you think about this problem/solution?

without having looked at the code, I got mixed feelings from your 
problem statement.

On the one hand, making VFS plugins depend on the (regular) libc is a 
direction I would stay away from. I worry that this direction creates 
problems, complexities, and wrong expectations that are far more 
difficult to handle than stubbing out or emulating a few POSIX calls 
from a ported 3rd-party library. The hosting of multiple VFS instances 
inside one component may be technically feasible but it is arguably not 
natural.

On the other hand, it is laudable that to got this to work.

BTW, the topic reminds me on Cedric's work on FUSE-based file systems 
discussed at [1].

[1] https://github.com/genodelabs/genode-world/issues/193

Cheers
Norman

-- 
Dr.-Ing. Norman Feske
Genode Labs

https://www.genode-labs.com · https://genode.org

Genode Labs GmbH · Amtsgericht Dresden · HRB 28424 · Sitz Dresden
Geschäftsführer: Dr.-Ing. Norman Feske, Christian Helmuth