mkfs_file/
mkfs_file.rs

1//! Example: Format a file as an ext4 filesystem
2//!
3//! This example creates a 10MB disk image file and formats it as ext4.
4
5use ext4_mkfs::{mkfs, FsType, IoBlockDevice, MkfsConfig};
6use std::fs::{File, OpenOptions};
7use std::io::{Seek, SeekFrom, Write};
8
9fn main() -> Result<(), Box<dyn std::error::Error>> {
10    let path = "test_disk.img";
11    let size: u64 = 10 * 1024 * 1024; // 10 MB
12
13    println!("Creating disk image: {} ({} bytes)", path, size);
14
15    // Create and size the file
16    {
17        let mut file = File::create(path)?;
18        file.seek(SeekFrom::Start(size - 1))?;
19        file.write_all(&[0])?;
20        file.sync_all()?;
21    }
22
23    // Open for read/write
24    let file = OpenOptions::new().read(true).write(true).open(path)?;
25
26    // Create block device wrapper (512-byte sectors)
27    let device = IoBlockDevice::new(file, 512, size);
28
29    // Configure and create filesystem
30    let config = MkfsConfig::new()
31        .fs_type(FsType::Ext4)
32        .block_size(4096)
33        .label("test_volume");
34
35    println!("Formatting as ext4...");
36    mkfs(device, config)?;
37
38    println!("Done! You can verify with: file {} or dumpe2fs {}", path, path);
39
40    Ok(())
41}
mkfs_file/mkfs_file.rs

mkfs_file/
mkfs_file.rs
