diff --git a/src/fd/mod.rs b/src/fd/mod.rs
index 7f1e168..e2a4eff 100644
--- a/src/fd/mod.rs
+++ b/src/fd/mod.rs
@@ -6,7 +6,7 @@ use async_trait::async_trait;
 use core::cell::RefCell;
 use lazy_static::lazy_static;
 
-pub type FDt = Arc<RefCell<dyn FileDescriptor>>;
+pub type FDt = Arc<AsyncMutex<dyn FileDescriptor>>;
 
 lazy_static! {
     pub static ref FD_TABLE: AsyncMutex<FDTable> = {
@@ -33,7 +33,7 @@ impl FDTable {
         FDTable { table: BTreeMap::new() }
     }
 
-    pub async fn register_fd(&mut self, fd: FDt) {
+    pub fn register_fd(&mut self, fd: FDt) {
         // TODO
         self.table.insert(fd.borrow().get_fd(), fd.clone());
         println!("Registered fd: {:?}", self.table.get(&FDId(1)).unwrap().borrow().get_fd());
diff --git a/src/fs/iso/fd.rs b/src/fs/iso/fd.rs
index 452f61e..95b8e04 100644
--- a/src/fs/iso/fd.rs
+++ b/src/fs/iso/fd.rs
@@ -1,5 +1,6 @@
 use crate::println;
 use crate::fd::{FDId, FileDescriptor, FDt};
+use crate::utils::mutex::AsyncMutex;
 
 use alloc::{sync::Arc, boxed::Box};
 use async_trait::async_trait;
@@ -11,7 +12,7 @@ pub struct IsoFD {
 
 impl IsoFD {
     pub fn new() -> FDt {
-        Arc::new(RefCell::new(IsoFD {
+        Arc::new(AsyncMutex::new(IsoFD {
             fd: FDId::new(),
         }))
     }
diff --git a/src/fs/iso/mod.rs b/src/fs/iso/mod.rs
index 48d938f..81297b3 100644
--- a/src/fs/iso/mod.rs
+++ b/src/fs/iso/mod.rs
@@ -6,9 +6,35 @@ use crate::drivers::atapi::{DRIVE};
 use crate::fd::{FD_TABLE, FDt};
 use crate::utils::unserialize;
 
+use super::FileSystem;
 use iso9660::{IsoPrimVolDesc, IsoDir};
 use fd::IsoFD;
 
+use alloc::{sync::Arc, boxed::Box};
+use async_trait::async_trait;
+
+struct IsoFS {
+}
+
+#[async_trait]
+impl FileSystem for IsoFS {
+    async fn open(&mut self, path: &str, flags: u32) -> Option<FDt> {
+        if flags != crate::syscalls::io::O_RDONLY {
+            return None;
+        }
+
+        let voldesc = get_prim_vol_desc().await;
+
+        if voldesc.std_identifier != "CD001".as_bytes() {
+            return None;
+        }
+
+        let fd = IsoFD::new();
+        FD_TABLE.lock().await.register_fd(fd.clone());
+        Some(fd.clone())
+    }
+}
+
 pub async fn get_prim_vol_desc() -> IsoPrimVolDesc {
     let desc_block = DRIVE
         .lock()
@@ -18,20 +44,4 @@ pub async fn get_prim_vol_desc() -> IsoPrimVolDesc {
         .read_block(iso9660::ISO_PRIM_VOLDESC_BLOCK)
         .await;
     *unserialize::<IsoPrimVolDesc>(desc_block.as_ptr())
-}
-
-pub async fn open(path: &str, flags: u32) -> Option<FDt> {
-    if flags != crate::syscalls::io::O_RDONLY {
-        return None;
-    }
-
-    let voldesc = get_prim_vol_desc().await;
-
-    if voldesc.std_identifier != "CD001".as_bytes() {
-        return None;
-    }
-
-    let fd = IsoFD::new();
-    FD_TABLE.lock().await.register_fd(fd.clone()).await;
-    Some(fd)
 }
\ No newline at end of file
diff --git a/src/fs/mod.rs b/src/fs/mod.rs
index b5da632..76d187f 100644
--- a/src/fs/mod.rs
+++ b/src/fs/mod.rs
@@ -1 +1,11 @@
-pub mod iso;
\ No newline at end of file
+pub mod iso;
+
+use crate::fd::FDt;
+
+use alloc::{sync::Arc, boxed::Box};
+use async_trait::async_trait;
+
+#[async_trait]
+pub trait FileSystem {
+    async fn open(&mut self, path: &str, flags: u32) -> Option<FDt>;
+}
\ No newline at end of file
diff --git a/src/utils/mutex.rs b/src/utils/mutex.rs
index d23a7d9..48f0c38 100644
--- a/src/utils/mutex.rs
+++ b/src/utils/mutex.rs
@@ -14,7 +14,7 @@ struct Lock {
     waker: Arc<AtomicWaker>,
 }
 
-pub struct AsyncMutex<T> {
+pub struct AsyncMutex<T: ?Sized> {
     lock: Lock,
     inner: UnsafeCell<T>,
 }