ubuntu@ubuntu:~$ sudo fsck /dev/sda1 
fsck from util-linux 2.26.2
e2fsck 1.42.12 (29-Aug-2014)
/dev/sda1 contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Inodes that were part of a corrupted orphan linked list found.  Fix<y>?