Yakov Galka wrote:
On Sat, Mar 23, 2013 at 2:42 PM, Joseph Van Riper < fleeb.fantastique@gmail.com> wrote:
[...] I have never seen a file system that wasn't, really, a tree with branches and leaves. It can have more than one base, but ultimately, it's a tree.
It is called a "forest". But filesystems aren't really forests. For starters, they are very often DAGs (you can hardlink the leaves). Much software assumes that path is a unique identifier of a resource and breaks on non-trees. If people would not make such assumption we could very well allow arbitrary graphs. The point is that there is no *a priori* reason that file systems are DAGs, it is the *result* of thinking of filesystems as trees of paths.
They can quite easily become non-DAGs with junction points / symlinks being able to create cycles.