[Tracker] Tracker support for a tag based filesystem using FUSE

[Greg Knittl <gknittl sympatico ca>]

Hi,

I've just come across Tracker and was intrigued by 
https://wiki.gnome.org/Projects/Tracker/WhatIsTracker >
"What does Tracker offer?" especially the statement:

"Users may completely move away from a folder-hierarchy based home 
folder, and instead organise their data into collections using tags. The 
combination of tagging support in the file-chooser, tagging awareness in 
Nautilus, or even a tag based filesystem using FUSE could allow radical 
exploration of new desktop ideas."

I've been investigating a much simpler version of this idea based on 
storing tags in extended attributes and displaying them through a FUSE.
From what I've learned so far about the Linux VFS (Virtual File System 
(Switch)) it strongly enforces a tree-like hierarchy and unique file names.
It's not clear if the VFS allows adding support for additional file 
types so it appears that tags would have to be transposed into 
directories in the VFS.
This leads to various challenges. especially in creating new files in 
the FUSE. I.e. where are you in relation to the underlying file system 
as you step through FUSE directories that are really tags? How do you 
indicate you are creating a new tag and not a new directory? could the 
FUSE implement a mktag command? Where should you create a new file and 
what tags should it have?

At the moment I'm thinking that using a FUSE to insert tags into the 
existing directory structure of an underlying file system might work for 
read and possibly write. This makes for deeper and potentially unwieldy 
directory structures. But if you start hiding directories from the 
underlying filesystem in the FUSE then updates become trickier.

Would appreciate your comments or pointers to any thoughts you've had 
about this issue.

thanks,
Greg