Added an InodeAttributes.Nlink field.

file_system.go

@@ -265,6 +265,9 @@ func init() {
 type InodeAttributes struct {
 	Size uint64
 
+	// The number of incoming hard links to this inode.
+	Nlink uint64
+
 	// The mode of the inode. This is exposed to the user in e.g. the result of
 	// fstat(2).
 	//