linking {TAIL ~ the original value} of the data unit to the update data before transferring the update data to the storage layer if transferring the update data to the storage layer results in updating a value of {HEAD ~ the data unit} 
linking { TAIL ~ the original value } of the data unit to the update data before transferring the update data to the storage layer if transferring the update data to the storage layer results in updating a value of { HEAD ~ the data unit }
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD