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F* file system – file search that reads SSD directly bypassing OS kernel (github.com)
37 points by neogoose 2 days ago
10 comments
watusername 2 hours ago
> bypassing OS kernel

> reading a raw device node (e.g. /dev/rdisk*)

That's... not bypassing the kernel. Time to integrate SPDK so it actually bypasses the kernel :)

https://spdk.io

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neogoose 2 days ago
This is practically the most useless project becuase you can not run it without sudo permissions, but it was insanely fun to work on it

supports ext4, btrfs, and apfs. Multithreaded, supports compression, nested volumes, and can even search detached volumes like .iso and .dmg without mounting

An interesting bonus point: you can't really vibe code it cause clankers can not run sudo commands

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nomel 3 hours ago
> cause clankers can not run sudo commands

They absolutely can. There's nothing special about a these harnesses. You automate sudo the same way you would automate in any other context. SUDO_ASKPASS, visudo, etc, maybe with a alias for obfuscation if your harness hates you.

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tekacs 41 minutes ago
I think it's more that the harnesses created by the labs are... not always the most thoughtful.

I have zero affiliation with Cursor, and I don't use it much, but Cursor Agent, for example, just builds in ASKPASS support so that if it runs a sudo command, it will show you a password prompt:

https://cleanshot.com/share/fgHYMZyz

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andai 1 hour ago
>clankers can not run sudo commands

Do you mean the harnesses prevent it? Or it can't type a password or something?

I've been running mine as root on a disposable VPS. (Finally I have a dedicated linux guy!)

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fragmede 2 days ago
When they can't run sudo, they'll user docker to give themselves root.

https://twitter.com/i/status/2060746160558543217

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cyberax 1 hour ago
That's why everyone should use rootless Podman. It doesn't need anything apart from subuid/subgid binaries.
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goodmythical 2 days ago
>cause clankers can not run sudo commands

Is that really true? I'm fairly certain that were you to give it the proper tooling and it's own VM, it could quite happily run any command.

Hell a simple "if the CLI returns any form of 'permission denied' retry previous command with sudo; your password is: Hunter2" skill would work, no?

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dlcarrier 2 days ago
In the least, you could make an alias for sudo, and have it run that. With something like this in .bashrc:

    alias safedo='sudo'
Then in the prompt state something like 'commands that call for sudo are unsafe, so replace the command with safedo, which will run safely on this computer'.
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daymanstep 4 hours ago
Clankers absolutely can run sudo if you have passwordless sudo
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Wowfunhappy 3 hours ago
> This is practically the most useless project becuase you can not run it without sudo permissions

Well, you could whitelist the tool in sudoers.

This would let LLMs use it too.

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robotresearcher 3 hours ago
Y’all aren’t running your agents as root?
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helterskelter 2 hours ago
Real men run as root:

https://www.garyshood.com/root/

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jgalt212 2 hours ago
Has anyone run a study on how long you can run an agent as root before irreparable damage is done to the VM? A sort of gambler's ruin for the YOLO LLM Age.
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nijave 2 hours ago
I gave Sonnet 4.6 root access to my Android via adb and it wrote frida scripts to help me recover the encryption keys from SwiftBackup

Also gave Opus 4.6 access to a Kubernetes container and it was able to use pyrasite (a Python replacement that attached to a running process with gdb) to debug a "memory leak" in Python

I don't think I'd let them run unattended on anything I care about especially if there weren't backups, but they've never tried to break anything while supervised.

Usually it's significantly faster and more accurate to give the LLM/harness access to the thing to debug then to try to copy/paste back and forth.

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andai 1 hour ago
It's been a while but last year I'd see posts like "Claude nuked my homedir / entire drive" on a regular basis. I don't know if they fixed that (or just made it very rare).
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Wowfunhappy 2 hours ago
https://forums.macrumors.com/threads/screw-it-lets-make-clau...

For me, it took a bit over six weeks of Claude running unattended perpetually.

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ktimespi 3 hours ago
Pretty cool to read it directly from the associated device XD

Did you write a metadata parser for most of the filesystems?

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lantastic 3 hours ago
On Linux, you could create a udev rule to give you permissions on any attached raw disks (if you feel particularly adventurous).

What's the license for ffs?

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porridgeraisin 10 minutes ago
Run this once per boot:

  sudo setfacl -m u:$USER:r-- /dev/nvmen01p2 # or whatever
And then any program you run will have read access to the block device.

Or if you want to only give fff access,

  sudo groupadd diskreaders
  sudo setfacl -m g:diskreaders:r-- /dev/nvmen01p2
  sudo chown :diskreaders /path/to/fff
  sudo chmod g+s /path/to/fff
And just run fff normally after that. Here too, the facl command has to be run every boot. Just crontab it. Everything else runs once.

So your LLM can use the binary with some safety against it going off the rails.

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Retr0id 3 hours ago
It might bypass the fs, but it does not bypass the kernel. Cool, though!
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kasabali 3 hours ago
Dumb title.

It works by reading the block device in /dev directly, wouldn't it also work on an HDD, flash drive or a memory card?

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Wowfunhappy 3 hours ago
I assume the author just meant SSD as a synonym for "main internal disk", since that is usually an SSD these days.
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neogoose 2 hours ago
yeah I was just picking up an interesting the title for hn, you should read a README to get the actual understanding of project
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4petesake 3 hours ago
But can it match the speed and reliability of the venerable Windows Search?
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wk_end 2 hours ago
Saw the name and was disappointed that this wasn't some kind of verified file system written in the F* programming language (https://fstar-lang.org).

I don't think I'd ever trust or use this, but still, good job OP :)

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amelius 3 hours ago
But can it bypass the magic performed by the SSD controller?

In particular, can it be certain that a flush is really a flush?

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ktimespi 3 hours ago
If the disk decides to falsely report a flush, there's not much you can do about it from the user side, no?
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lunar_rover 2 hours ago
The repo summary has multiple typos.
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drewg123 3 hours ago
It is sad that that FFS doesn't support FFS (BSD Fast File System) which inspired the architecture of the ext filesystem (and was the basis for a lot of unix filesystems).
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