Implement sync for ext2 and exfat

kernel/src/fs/exfat/inode.rs

@@ -1683,6 +1683,8 @@ impl Inode for ExfatInode {
         let fs_guard = fs.lock();
         inner.sync_all(&fs_guard)?;
 
+        fs.block_device().sync()?;
+
         Ok(())
     }
 
@@ -1692,6 +1694,8 @@ impl Inode for ExfatInode {
         let fs_guard = fs.lock();
         inner.sync_data(&fs_guard)?;
 
+        fs.block_device().sync()?;
+
         Ok(())
     }
 

kernel/src/fs/ext2/impl_for_vfs/inode.rs

@@ -191,11 +191,15 @@ impl Inode for Ext2Inode {
     }
 
     fn sync_all(&self) -> Result<()> {
-        self.sync_all()
+        self.sync_all()?;
+        self.fs().block_device().sync()?;
+        Ok(())
     }
 
     fn sync_data(&self) -> Result<()> {
-        self.sync_data()
+        self.sync_data()?;
+        self.fs().block_device().sync()?;
+        Ok(())
     }
 
     fn fs(&self) -> Arc<dyn FileSystem> {