tabfs

Setup

You need to both install the Chrome extension and run the native filesystem.

Install the Chrome extension

Go to the Chrome extensions page.

Enable Developer mode. Load-unpacked the extension/ folder in this repo.

Run the C filesystem

First, make sure you git submodule update --init to get the mmx and cJSON dependencies. And make sure you have FUSE.

$ cd fs
$ mkdir mnt
$ make [unmount] mount

Connect the browser extension to the filesystem

Once the filesystem is running and awaiting a WebSocket connection, you need to tell the browser extension to connect to it.

Click the 'T' icon the extension put in your browser toolbar. The icon badge should change from red to blue, and the filesystem program should print that it's connected in the terminal.

Now your browser tabs should be mounted in fs/mnt!

Design

• extension/: Browser extension, written in JS
• fs/: Native FUSE filesystem, written in C
  • tabfs.c: Main thread. Talks to FUSE, implements fs operations.
  • ws.c: Side thread. Runs WebSocket server. Talks to browser.
  • common.c: Communications interface between tabfs and ws.

When you, say, cat a file in the tab filesystem:

1. cat makes something like a read syscall,

2. which goes to the FUSE kernel module which backs that filesystem,

3. FUSE forwards it to the tabfs_read implementation in our userspace filesystem in fs/tabfs.c,

4. then tabfs_read rephrases the request as a JSON string and forwards it using common_send_tabfs_to_ws to fs/ws.c,

5. and fs/ws.c forwards it to our browser extension over WebSocket connection;

6. our browser extension in extension/background.js handles the incoming message and calls the browser APIs to construct the data for that synthetic file;

7. then the data gets sent back in a JSON message to ws.c and then back to tabfs.c and finally back to FUSE and the kernel and cat.

(very little actual work happened here, tbh. it's all just marshalling)

TODO: make diagrams?