feat: implement ext4fs driver

kernel/Cargo.toml

@@ -14,6 +14,7 @@ simple_range = { path = "../lib/simple_range" }
 virtio-drivers = "0.8.0"
 fatfs = { version = "0.4", git = "https://github.com/rafalh/rust-fatfs", default-features = false, features = ["lfn", "alloc"] }
 spin = "0.9.8"
+ext4_rs = "1.1.0"
 
 [profile.release]
 debug = true

kernel/src/fs/ext4/mod.rs

@@ -0,0 +1,30 @@
+pub use virtio::*;
+
+use alloc::sync::Arc;
+use core::ptr::NonNull;
+use ext4_rs::Ext4;
+use virtio_drivers::{device::blk::VirtIOBlk, transport::mmio::{MmioTransport, VirtIOHeader}};
+use crate::{board::VIRT_IO, drivers::VirtIOHal};
+
+mod virtio;
+
+// region Ext4Fs begin
+pub struct Ext4Fs {
+    pub inner: Ext4,
+}
+
+impl Ext4Fs {
+    pub fn new(device_id: usize) -> Self {
+        let addr = VIRT_IO + device_id * 0x1000;
+        let header = NonNull::new(addr as *mut VirtIOHeader).unwrap();
+        let transport =
+            unsafe { MmioTransport::new(header).expect("Failed to create mmio transport") };
+        let blk = VirtIOBlk::<VirtIOHal, MmioTransport>::new(transport)
+            .expect("Failed to create VirtIOBlk");
+
+        let device = VirtIODisk::new(blk);
+        let ext4 = Ext4::open(Arc::new(device));
+        Self { inner: ext4 }
+    }
+}
+// region Ext4Fs end

kernel/src/fs/ext4/virtio.rs

@@ -0,0 +1,45 @@
+use core::cell::RefMut;
+use crate::{drivers::VirtIOHal, sync::UPSafeCell};
+use alloc::vec;
+use ext4_rs::BlockDevice;
+use virtio_drivers::{device::blk::VirtIOBlk, transport::mmio::MmioTransport};
+
+const BLOCK_SIZE: usize = 512;
+
+// region VirtIODisk begin
+pub struct VirtIODisk {
+    inner: UPSafeCell<VirtIODiskInner>,
+}
+
+impl VirtIODisk {
+    pub fn new(virt_io_blk: VirtIODiskInner) -> Self {
+        VirtIODisk {
+            inner: unsafe { UPSafeCell::new(virt_io_blk) },
+        }
+    }
+
+    fn inner_mut(&self) -> RefMut<VirtIODiskInner> {
+        self.inner.exclusive_access()
+    }
+}
+
+impl BlockDevice for VirtIODisk {
+    fn read_offset(&self, offset: usize) -> alloc::vec::Vec<u8> {
+        let mut inner = self.inner_mut();
+        let mut buf = vec![0; BLOCK_SIZE];
+        inner
+            .read_blocks(offset, &mut buf)
+            .expect("Error occurred when reading VirtIOBlk");
+        buf
+    }
+
+    fn write_offset(&self, offset: usize, data: &[u8]) {
+        let mut inner = self.inner_mut();
+        inner
+            .write_blocks(offset, &data)
+            .expect("Error occurred when writing VirtIOBlk");
+    }
+}
+// region VirtIODisk end
+
+type VirtIODiskInner = VirtIOBlk<VirtIOHal, MmioTransport>;

kernel/src/fs/mod.rs

@@ -6,6 +6,7 @@ pub use stdio::*;
 use alloc::sync::Arc;
 use lazy_static::lazy_static;
 
+pub mod ext4;
 pub mod fat;
 mod interface;
 mod path;