a cross-platform rust ext4 crate support read/write/mkdir

read/write example

rust version rustc 1.77.0-nightly nightly-2023-12-28

git checkout dev
python3 gen_test_files.py
sh 1.sh

how to use

impl BlockDevice Trait

pub struct Disk {}
impl BlockDevice for Disk {
    fn read_offset(&self, offset: usize) -> Vec<u8> {}
    fn write_offset(&self, offset: usize, data: &[u8]) {}
}

open ext4

let disk = Arc::new(Disk {});
let ext4 = Ext4::open(disk);

read/write/mkdir

// read regular file
let path =
    "/test_files/1.txt";
let mut ext4_file = Ext4File::new();
let r = ext4.ext4_open(&mut ext4_file, path, "r+", false);
if let Err(e) = r {
    log::info!("open file error {:?}", e);
    panic!("open file error")
}
log::info!("ext4_file inode {:?}", ext4_file.inode);
let mut read_buf = vec![0u8; 0x20000000];
let mut read_cnt = 0;
let r = ext4.ext4_file_read(&mut ext4_file, &mut read_buf, 0x20000000 , &mut read_cnt);
if let Err(e) = r {
    log::info!("read file error {:?}", e);
    panic!("read file error")
}
log::info!("read data sample {:x?}", &read_buf[0..10]);

// read link
let path =
"/test_files/linktest";
let mut ext4_file = Ext4File::new();
let r = ext4.ext4_open(&mut ext4_file, path, "r+", false);
if let Err(e) = r {
    log::info!("open file error {:?}", e);
    panic!("open file error")
}
log::info!("ext4_file inode {:?}", ext4_file.inode);
let mut read_buf = vec![0u8; 0x1000];
let mut read_cnt = 0;
let r = ext4.ext4_file_read(&mut ext4_file, &mut read_buf, 0x1000 , &mut read_cnt);
if let Err(e) = r {
    log::info!("read file error {:?}", e);
    panic!("read file error")
}
log::info!("read data sample {:x?}", &read_buf[0..10]);

// dir
log::info!("----mkdir----");
for i in 0..10{
    let path = format!("dirtest{}", i);
    let path = path.as_str();
    let r = ext4.ext4_dir_mk(&path);
    if let Err(e) = r {
        log::info!("dir make error {:?}", e);
        panic!("dir make error")
    }
}

// write test
// file
log::info!("----write file in dir----");
for i in 0..10{
    const WRITE_SIZE: usize = 4096 * 10;
    let path = format!("dirtest{}/write_{}.txt", i, i);
    let path = path.as_str();
    let mut ext4_file = Ext4File::new();
    let r = ext4.ext4_open(&mut ext4_file, path, "w+", true);
    if let Err(e) = r {
        log::info!("open file error {:?}", e);
        panic!("open file error")
    }
    let write_data: [u8; WRITE_SIZE] = [0x41 + i as u8; WRITE_SIZE];
    ext4.ext4_file_write(&mut ext4_file, &write_data, WRITE_SIZE);
    // test
    let r = ext4.ext4_open(&mut ext4_file, path, "r+", false);
    if let Err(e) = r {
        log::info!("open file error {:?}", e);
        panic!("open file error")
    }
    
    let mut read_buf = vec![0u8; 1024];
    let mut read_cnt = 0;
    let r = ext4.ext4_file_read(&mut ext4_file, &mut read_buf, 10 , &mut read_cnt);
    if let Err(e) = r {
        log::info!("read file error {:?}", e);
        panic!("read file error")
    }
    log::info!("read data sample {:x?}", &read_buf[0..10]);
}