Tracking intermix of writes and un-map commands across power cycles

A storage device, comprising:

• non-volatile memory;
• one or more processors;
• and
• controller memory storing one or more programs configured for execution by the one or more processors, the one or more programs including instructions for:
• receiving, at the storage device, a plurality of commands from a host to which the storage device is operatively coupled, the plurality of commands from the host including write commands and un-map commands;
• maintaining a log corresponding to write commands and un-map commands from the host;
• maintaining a mapping table in volatile memory, the mapping table used to translate logical addresses in a logical address space available to the host to physical addresses in a physical address space of the storage device, wherein the log is distinct from the mapping table;
• saving the mapping table, on a scheduled basis that is independent of the plurality of commands from the host, to the non-volatile memory;
• saving the log to the non-volatile memory;
• and
• upon power up of the storage device, rebuilding the mapping table from the saved mapping table in the non-volatile memory and from the saved log in the non-volatile memory.

A non-transitory computer-readable storage medium, storing one or more programs configured for execution by one or more processors of a storage device, the one or more programs including instructions for:

• receiving, at the storage device, a plurality of commands from a host to which the storage device is operatively coupled, the plurality of commands from the host including write commands and un-map commands, the storage device including non-volatile memory;
• maintaining a log corresponding to write commands and un-map commands from the host;
• maintaining a mapping table in volatile memory, the mapping table used to translate logical addresses in a logical address space available to the host to physical addresses in a physical address space of the storage device, wherein the log is distinct from the mapping table;
• saving the mapping table, on a scheduled basis that is independent of the plurality of commands from the host, to the non-volatile memory;
• saving the log to the non-volatile memory;
• and
• upon power up of the storage device, rebuilding the mapping table from the saved mapping table in the non-volatile memory and from the saved log in the non-volatile memory.