I read all over the internet to get your HDD replaced if you are getting the S.M.A.R.T status failing (or failed)
Now what I did was dissembled my macbook air to replace the HDD, but unfortunately i didn’t have the right zif cable to replace the HDD, so i simply reconnected my old HDD back.
What i see now is the same HDD with S.M.A.R.T status verified (in other words its fixed), its not making any sense to me but working so far.
But before you do any thing i would strongly suggest to backup your full drive or atleast important data before you try anything.
Now my HDD status is
SAMSUNG HS082HB:
Capacity: 80.03 GB (80,026,361,856 bytes)
Model: SAMSUNG HS082HB
Revision: NL101-06
Serial Number: S1BPJ16Q421794
Removable Media: No
Detachable Drive: No
BSD Name: disk0
Protocol: ATA
Unit Number: 0
Socket Type: Internal
Low Power Polling: No
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Verified
Volumes:
Macintosh HD:
Capacity: 68.59 GB (68,585,259,008 bytes)
Available: 32.24 GB (32,244,850,688 bytes)
Writable: Yes
File System: Journaled HFS+
BSD Name: disk0s2
Mount Point: /
which am sure was failed or failing.
and hai am not responsible for anything that goes wrong with you, never trust the internet 
