tarfs

KO | EN

gitlite — search

#javascript #python #hacktoberfest #react #ai #typescript #llm #go #golang #android #machine-learning #rust #deep-learning #linux

(★ 21)

tar file system as loadable kernel module

tarfs Latest Version Download

Download Latest Version (.zip)

// repository documentation

Was this content helpful?

★ 0 (0 ratings)

# tarfs

tarfs is implemented as Linux kernel module filesystem driver.  It's more of a
research thing.  If you're interested in actually using something like this,
consider writing it using libFuse :)

## Features

* Supports GNU tar files
* Regular files, directories and symlinks
* UID, GID, access/modification/creation time
* Read-only access to files and directories

## Compiling

You'll require the linux development files.  For ArchLinux, you need the
`linux-headers` packet.

After that, just run `make` to build the `tarfs.ko`, which is a loadable
kernel module.

**Note**: The module was tested with Linux `4.9.11`, on a `x64 ArchLinux`
          computer.

## Usage

```sh
# If not already done, build the module
make

# Now you can load the module:
sudo insmod tarfs.ko

# You need a mount directory
mkdir mnt

# Mount some tar archive.  A sample one is included:
sudo mount sample.tar -o loop -t tarfs mnt

# Discover the archives content
ls mnt -R
cat mnt/hello.c

# Unmount
sudo umount mnt

# And unload the kernel module
sudo rmmod tarfs.ko
```

## File overview

* **driver.c** The driver code interfacing with Linux
* **device.c/h** Code to read from the underlying block device
* **tar.c/h** Code to read the tar file
* **gnutar.h** Header definition for tar files, taken from
  https://www.gnu.org/software/tar/manual/html_node/Standard.html

## Implementation

This project focuses on the interaction part with Linux.  That's why the
implementation of the Tar reading code is kept really simple: On mount, all
file entries are read from the tar file, and stored as a linked list.  Some
data, like the file path, is stored separatly in the structure to ease access.

When Linux wants the module to list a directory, or find a specific file, the
whole linked list is iterated, making most file system operations `O(n)`.

## Attention

Please note that you're actually loading stuff into your kernel.  That means the
module runs with highest permissions possible (Ring 0 on x86 machines).  Also,
if something goes really wrong, your entire computer could hang/crash/freeze.

It's recommended to try this in a virtual machine.  You can create one easily
using programs like `QEMU` or `VirtualBox`.

## License

The enclosed source code, and the `sample.tar` file including its contents, are
subject to the **General Public License version 3** (**GPLv3**).  Please see the
included `LICENSE` file for the whole license text.  If you're interested in a
legally non-binding explanation of this license, have a look at
[its tl;drLegal page](https://tldrlegal.com/license/gnu-general-public-license-v3-(gpl-3)).

## Still reading?

Thanks for your interest - Have a nice day, and happy hacking!

tarfs

tarfs Latest Version Download

Today's picks

Was this content helpful?

Recent Feedback

tarfs

tarfs Latest Version Download

Today's picks

Was this content helpful?

Recent Feedback

Download README