Root filesystem check failed

While updating ubuntu my system crashed and after restarting and entering to ubuntu I get the message Root filesystem check failed.Very much similar to the post Ubuntu 13.04 to 13.10: Filesystem check or mount failed. I tried to fix it with the instruction mentioned there as

mount -o remount,rw /dpkg --configure -amount -o remount,ro /syncreboot

But the problem is after executing mount -o remount,rw / I get:

mount: cannot remount block device /host/ubuntu/disks/root.disk read-write.is write-protected.

After executing dpkg --configure -a I get:

dpkg: error: unable to access dpkg status area: Read-only file system. 

After executing the remaining commands, nothing happens apart from a reboot at the end.
Can somebody please suggest a fix.