szcnorya / vsfsd

A I-node based memory file system implementation.

vsfsd - Very Simple File System (Demon)

A I-node based memory file system implementation. Implemented in C++.

Intro

The program organized a allocated memory as a file system to manage.

Providing following functions for external user.

1. Init file system with given disk size and block size
2. create/delete the file/directory
3. read/write file in binary stream
4. change pwd
5. copy file to new path

Implemented detail

Disk layout

Disk: super_block | block_bitmap | inode_bitmap | inode_table | data area

super_block: magic number to specify vsfsd, and some statistic data to maintain the file system.

struct super_block{
    //Statistic INFO
    u32 inodes_count;
    u32 used_inode;
    u32 block_count;
    u32 used_block_count;
    u32 blockBitmapBlock;
    u32 iNodeBitmapBlock;
    u32 iNodeTableBlock;
    u32 dataBlock;
    u32 block_size;
    u32 magic;
};

block_bitmap: Use/Unused map for block inode_bitmap: Use/Unused map for inode inode_table : Inode data area data_area : blocks

Notice

• Minimum addressable unit is byte.
• All address are 32-bit.
• Only level-1 indirect block is implemented