fs_ext4/
lib.rs

1//! EXT4 filesystem component for Strat9-OS
2//!
3//! This component provides EXT4 filesystem support using the ext4_rs library.
4//! It implements the filesystem abstraction for Strat9-OS and provides
5//! read/write access to EXT4 volumes.
6
7#![no_std]
8
9extern crate alloc;
10
11use alloc::{sync::Arc, vec::Vec};
12use core::fmt;
13
14// Re-export the ext4_rs types
15pub use ext4_rs::{Ext4, Ext4Error};
16
17/// Block device trait that ext4_rs requires
18///
19/// This trait must be implemented by any device driver that wants to
20/// provide block-level access to EXT4 filesystems.
21pub trait BlockDevice: Send + Sync {
22    /// Read data from the device at the given byte offset
23    fn read_offset(&self, offset: usize) -> Result<Vec<u8>, BlockDeviceError>;
24
25    /// Write data to the device at the given byte offset
26    fn write_offset(&mut self, offset: usize, data: &[u8]) -> Result<(), BlockDeviceError>;
27
28    /// Get the size of the device in bytes
29    fn size(&self) -> Result<usize, BlockDeviceError>;
30}
31
32/// Errors that can occur during block device operations
33#[derive(Debug)]
34pub enum BlockDeviceError {
35    /// I/O error
36    Io,
37    /// Invalid offset
38    InvalidOffset,
39    /// Device not ready
40    NotReady,
41    /// Other error
42    Other,
43}
44
45impl fmt::Display for BlockDeviceError {
46    /// Implements fmt.
47    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
48        match self {
49            BlockDeviceError::Io => write!(f, "I/O error"),
50            BlockDeviceError::InvalidOffset => write!(f, "Invalid offset"),
51            BlockDeviceError::NotReady => write!(f, "Device not ready"),
52            BlockDeviceError::Other => write!(f, "Other error"),
53        }
54    }
55}
56
57/// EXT4 Filesystem wrapper for Strat9-OS
58pub struct Ext4FileSystem {
59    // TODO: Use actual ext4_rs once we figure out the BlockDevice trait mismatch
60    _marker: core::marker::PhantomData<()>,
61}
62
63impl Ext4FileSystem {
64    /// Mount an EXT4 filesystem from a block device
65    pub fn mount<D: BlockDevice + 'static>(_device: Arc<D>) -> Result<Self, ()> {
66        // TODO: Actually mount ext4_rs
67        // For now, return stub filesystem
68        Ok(Self {
69            _marker: core::marker::PhantomData,
70        })
71    }
72}
73
74/// Strat9-OS filesystem operations
75impl Ext4FileSystem {
76    /// List entries in a directory
77    pub fn read_dir(&self, _path: &str) -> Result<Vec<DirEntry>, ()> {
78        // Not implemented yet: avoid returning fake successful data.
79        Err(())
80    }
81
82    /// Open a file for reading
83    pub fn open(&self, _path: &str) -> Result<File, ()> {
84        // Not implemented yet: avoid returning a fake file handle.
85        Err(())
86    }
87
88    /// Create a new file
89    pub fn create(&mut self, _path: &str) -> Result<File, ()> {
90        // Not implemented yet: avoid reporting a fake successful create.
91        Err(())
92    }
93}
94
95/// Directory entry
96#[derive(Debug)]
97pub struct DirEntry {
98    pub name: alloc::string::String,
99    pub inode: u64,
100    pub file_type: FileType,
101}
102
103/// File type
104#[derive(Debug, Clone, Copy, PartialEq, Eq)]
105pub enum FileType {
106    RegularFile,
107    Directory,
108    SymLink,
109    CharDevice,
110    BlockDevice,
111    Fifo,
112    Socket,
113    Unknown,
114}
115
116/// File handle
117#[derive(Debug)]
118pub struct File {
119    _inode: u64,
120    size: u64,
121    offset: u64,
122}
123
124impl File {
125    /// Read data from the file
126    pub fn read(&mut self, _buf: &mut [u8]) -> Result<usize, ()> {
127        Err(())
128    }
129
130    /// Write data to the file
131    pub fn write(&mut self, _buf: &[u8]) -> Result<usize, ()> {
132        Err(())
133    }
134
135    /// Seek to a position in the file
136    pub fn seek(&mut self, pos: u64) -> Result<u64, ()> {
137        self.offset = pos;
138        Ok(self.offset)
139    }
140
141    /// Get the file size
142    pub fn size(&self) -> u64 {
143        self.size
144    }
145}
fs_ext4/lib.rs

fs_ext4/
lib.rs
