diff --git a/lib/filesystem.js b/lib/filesystem.js
index 3d7e3d81..28e390ee 100644
--- a/lib/filesystem.js
+++ b/lib/filesystem.js
@@ -715,15 +715,16 @@ FS.prototype.GetFullPath = function(idx) {
     var path = "";
 
     while(idx != 0) {
-        path = "/" + this.inodes[idx].name + path;
-        idx = this.inodes[idx].parentid;
+        path = "/" + this.GetInode(idx).name + path;
+        idx = this.GetParent(idx);
     }
     return path.substring(1);
 };
 
 // no double linked list. So, we need this
 FS.prototype.FindPreviousID = function(idx) {
-    var inode = this.GetInode(idx);
+    var inode = this.inodes[idx];
+    dbg_assert(this.should_be_linked(inode), "Filesystem FindPreviousID assumes linked inode");
     var id = this.inodes[inode.parentid].firstid;
     while(id != -1) {
         if (this.inodes[id].nextid == idx) return id;