I have no clue where the commands you cited come from
Please give us some link!
Anyways - your reader partition seems to be corrupted. I guess you just have to format it via
mkdosfs -n READER -F 32 /dev/mmcblk2p4
to make it accessible again.
BUT: the commands you listed aim to restore the system partition from a tar file on the reader parition - which won't be there now, so you just ran into a dead end.
I highly recommend you not to blindly enter some commands you find somewhere on the internet, not knowing what exactly they are aiming for.