Implement ext2 filesystem driver

[Martin Decky]

Implement a native HelenOS driver for the ext2 file system.

Details

The new driver should be realized as a standalone server process which plugs itself into the HelenOS VFS framework and implements the VFS and libfs interfaces in the ext2 specific way.

The implementation can proceed in two phases. In the first phase, read-only support should be implemented. The second phase will comprise of adding write support.

What Gains and Benefits will this bring?

The only persistent file system supported by HelenOS so far has been FAT16. This file system has some inconvenient limitations such as the 8.3 file names and, which is more important, does not force VFS to provide interfaces for writing back the superblock. On the other hand, ext2 is a reasonably advanced file system commonly used on the Linux platform and its implementation will lead to adding needed abstractions to the VFS protocol. This will benefit future additions of other persistent file systems.

Difficulty

medium

Required skills

A successful applicant will have good skills of programming in the C language and also the ability to program in a multi-server environment, which includes communicating using HelenOS IPC.

Documentation

The ext2 file system on-disk format is described in a document linked from the file system section of our developer documentation page. The file system framework is described in the file system design document and HelenOS IPC is documented in the IPC for Dummies article.

[Jakub Jermář]

Changing the Summary in order to be specific.