Re: [RFC 0/7] [RFC] cramfs: fake write support

[David Newall <davidn@davidnewall.com>]

arnd@arndb.de wrote:
> Many existing systems currently use unionfs or aufs for this
> purpose, by overlaying a tmpfs over a read-only file
> system like cramfs, squashfs or iso9660. IMHO, it would
> be a much nicer solution to not require unionfs for a simple
> case like this, but rather have support for it in the file
> system. If people find this useful, we can do the same in
> other read-only file system.
>   

I don't agree that it is nicer to do this in cramfs.  I prefer the
technique of union of a tmpfs over some other fs because a single
solution that works with all filesystems is better than re-implementing
the same idea in multiple filesystems.  Multiple implementations is a
recipe for bugs and feature mismatch.