1. A mass storage controller for providing improved data availability, comprising: a volatile memory, for storing posted-write data; a non-volatile memory, coupled to said volatile memory, for backing up said posted-write data from said volatile memory, in response to a loss of main power; a battery, coupled to supply power to said volatile memory in response to said loss of main power; an indicator, for indicating whether said battery continued to supply power to said volatile memory until said main power was restored; and control logic, coupled to said indicator, configured to forego restoring said posted-write data to said volatile memory from said non-volatile memory in response to said main power being restored, if said indicator indicates said battery continued to supply power to said volatile memory until said main power was restored.