diff --git a/src/bin/mksfs.rs b/src/bin/mksfs.rs
index 17dc102..a959f42 100644
--- a/src/bin/mksfs.rs
+++ b/src/bin/mksfs.rs
@@ -2,12 +2,12 @@ extern crate lib;
 
 use std::env;
 use std::fs;
-use std::io::Read;
+use std::io::{Read, Write, Result};
 use std::path::Path;
+use std::mem::uninitialized;
 use lib::*;
 
-fn main () {
-    println!("USAGE: <zip|unzip> <PATH> <IMG>");
+fn main() -> Result<()> {
     let args: Vec<_> = env::args().collect();
     let cmd = &args[1];
     let dir_path = Path::new(&args[2]);
@@ -15,47 +15,81 @@ fn main () {
     match cmd.as_str() {
         "zip" => zip(dir_path, img_path),
         "unzip" => unzip(dir_path, img_path),
-        _ => panic!("Invalid command: {}", cmd),
+        _ => {
+            println!("USAGE: <zip|unzip> <PATH> <IMG>");
+            panic!("Invalid command: {}", cmd);
+        },
     }
 }
 
-fn zip(path: &Path, img_path: &Path) {
-    use lib::std_impl;
-
-    let mut img = fs::File::create(img_path)
-        .expect(format!("Failed to create file: {:?}", img_path).as_str());
+fn zip(path: &Path, img_path: &Path) -> Result<()> {
+    let img = fs::OpenOptions::new().read(true).write(true).create(true).open(img_path)?;
     let sfs = SimpleFileSystem::create(Box::new(img), 0x1000000);
     let inode = sfs.root_inode();
-    zip_dir(path, inode);
+    zip_dir(path, inode)?;
+    sfs.sync().expect("Failed to sync");
+    Ok(())
 }
 
-fn zip_dir(path: &Path, inode: INodePtr) {
-    println!("{:?}", path);
+fn zip_dir(path: &Path, inode: INodePtr) -> Result<()> {
     let dir = fs::read_dir(path).expect("Failed to open dir");
     for entry in dir {
-        let entry = entry.unwrap();
+        let entry = entry?;
         let name_ = entry.file_name();
         let name = name_.to_str().unwrap();
-        let type_ = entry.file_type().unwrap();
+        let type_ = entry.file_type()?;
         if type_.is_file() {
-            let inode = inode.borrow_mut().create(name, FileType::File)
-                .expect("Failed to create INode");
-            let mut file = fs::File::open(entry.path())
-                .expect("Failed to open file");
-            let mut buf = Vec::<u8>::new();
-            file.read_to_end(&mut buf)
-                .expect("Failed to read file");
-            inode.borrow_mut().write_at(0, buf.as_ref())
-                .expect("Failed to write image");
-            println!("{:?}", entry.path());
+            let inode = inode.borrow_mut().create(name, FileType::File).expect("Failed to create INode");
+            let mut file = fs::File::open(entry.path())?;
+            inode.borrow_mut().resize(file.metadata().unwrap().len() as usize).expect("Failed to resize INode");
+            let mut buf: [u8; 4096] = unsafe { uninitialized() };
+            let mut offset = 0usize;
+            let mut len = 4096;
+            while len == 4096 {
+                len = file.read(&mut buf)?;
+                inode.borrow().write_at(offset, &buf).expect("Failed to write image");
+                offset += len;
+            }
         } else if type_.is_dir() {
-            let inode = inode.borrow_mut().create(name, FileType::Dir)
-                .expect("Failed to create INode");
-            zip_dir(entry.path().as_path(), inode);
+            let inode = inode.borrow_mut().create(name, FileType::Dir).expect("Failed to create INode");
+            zip_dir(entry.path().as_path(), inode)?;
         }
     }
+    Ok(())
 }
 
-fn unzip(path: &Path, img_path: &Path) {
+fn unzip(path: &Path, img_path: &Path) -> Result<()> {
+    let img = fs::File::open(img_path)?;
+    let sfs = SimpleFileSystem::open(Box::new(img)).expect("Failed to open sfs");
+    let inode = sfs.root_inode();
+    fs::create_dir(&path)?;
+    unzip_dir(path, inode)
+}
 
+fn unzip_dir(path: &Path, inode: INodePtr) -> Result<()> {
+    let files = inode.borrow().list().expect("Failed to list files from INode");
+    for name in files.iter().skip(2) {
+        let inode = inode.borrow().lookup(name.as_str()).expect("Failed to lookup");
+        let mut path = path.to_path_buf();
+        path.push(name);
+        let info = inode.borrow().info().expect("Failed to get file info");
+        match info.type_ {
+            FileType::File => {
+                let mut file = fs::File::create(&path)?;
+                let mut buf: [u8; 4096] = unsafe { uninitialized() };
+                let mut offset = 0usize;
+                let mut len = 4096;
+                while len == 4096 {
+                    len = inode.borrow().read_at(offset, buf.as_mut()).expect("Failed to read from INode");
+                    file.write(&buf[..len])?;
+                    offset += len;
+                }
+            }
+            FileType::Dir => {
+                fs::create_dir(&path)?;
+                unzip_dir(path.as_path(), inode)?;
+            }
+        }
+    }
+    Ok(())
 }
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