F* file system – file search that reads SSD directly bypassing OS kernel

15 pointsposted 2 days ago
by neogoose

17 Comments

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

nomel

31 minutes 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.

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?

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'.

daymanstep

an hour ago

Clankers absolutely can run sudo if you have passwordless sudo

Wowfunhappy

an hour 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.

ktimespi

42 minutes ago

Pretty cool to read it directly from the associated device XD

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

lantastic

an hour 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?

kasabali

29 minutes 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?

Wowfunhappy

25 minutes ago

I assume the author just meant SSD as a synonym for "main internal disk", since that is usually an SSD these days.

Retr0id

28 minutes ago

It might bypass the fs, but it does not bypass the kernel. Cool, though!

drewg123

10 minutes 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).

4petesake

42 minutes ago

But can it match the speed and reliability of the venerable Windows Search?

amelius

an hour 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?

ktimespi

44 minutes ago

If the disk decides to falsely report a flush, there's not much you can do about it from the user side, no?