diff --git a/src/vm/mmap.c b/src/vm/mmap.c
index 64ad28f..4e5a620 100644
--- a/src/vm/mmap.c
+++ b/src/vm/mmap.c
@@ -67,26 +67,27 @@ mmap_unmap (struct mmap_entry *mmap)
      if necessary. */
   off_t length = file_length (mmap->file);
   for (off_t ofs = 0; ofs < length; ofs += PGSIZE)
-  {
-    void *upage = mmap->upage + ofs;
-
-    /* Get the SPT page entry for this page. */
-    struct page_entry *page = page_get(thread_current (), upage);
-    if (page == NULL)
-      continue;
-
-    /* Write the page back to the file if it is dirty. */
-    if (pagedir_is_dirty (thread_current ()->pagedir, upage))
     {
-      lock_acquire (&filesys_lock);
-      file_write_at (mmap->file, upage, page->read_bytes, ofs);
-      lock_release (&filesys_lock);
+      void *upage = mmap->upage + ofs;
+
+      /* Get the SPT page entry for this page. */
+      struct page_entry *page = page_get(thread_current (), upage);
+      if (page == NULL)
+        continue;
+
+      /* Write the page back to the file if it is dirty. */
+      if (pagedir_is_dirty (thread_current ()->pagedir, upage))
+        {
+          lock_acquire (&filesys_lock);
+          file_write_at (mmap->file, upage, page->read_bytes, ofs);
+          lock_release (&filesys_lock);
+        }
+
+      /* Remove the page from the supplemental page table. */
+      hash_delete (&thread_current ()->pages, &page->elem);
     }
 
-    /* Remove the page from the supplemental page table. */
-    hash_delete (&thread_current ()->pages, &page->elem);
-  }
-
+  /* Close the file and free the mmap entry. */
   file_close (mmap->file);
   free (mmap);
 }