Extent metadata update logging and checkpointing

A non-transitory computer readable storage medium containing executable program instructions for execution by a processor at a storage system having a memory, the storage system coupled to one or more solid state drives (SSDs), comprising program instructions that:

• receive a write request, the write request having an extent;
• apply a hash function to the extent to generate a table index;
• store a portion of the table index in a slot of a table, the table stored in the memory, the slot including a location of the extent on the one or more SSDs;
• determine whether the slot has been written to a checkpoint;
• in response to determining that the slot has been written to the checkpoint, record the slot in a first log, wherein the first log is written to the one or more SSDs, wherein the first log is organized in reverse chronological order;
• and
• in response to determining that the slot has not been written to the checkpoint, record the slot in a second log, wherein the second log is written to the one or more SSDs, wherein the second log is organized in reverse chronological order.

A storage system having a memory connected to a processor via a bus, the storage system comprising:

• a storage array coupled to the storage system and having one or more solid state drives (SSDs);
• a storage I/O stack executing on the processor of the storage system, the storage I/O stack when executed operable to:
• receive a write request, the write request having an extent;
• apply a hash function to the extent to generate a hash table index and a hash table selector;
• select a cuckoo table from a plurality of cuckoo tables in the memory;
• store a portion of the hash table index in a slot of the selected cuckoo table, the slot including a location of the extent on the one or more SSDs;
• determine whether the slot has been written to a first checkpoint;
• and
• in response to determining that the slot has been written to the first checkpoint, record the slot in a first log, wherein the first log is written to the one or more SSDs.

A storage system having a memory connected to a processor via a bus, the storage system comprising:

• a storage array coupled to the storage system and having one or more solid state drives (SSDs);
• a storage I/O stack executing on the processor of the storage system, the storage I/O stack when executed operable to:
• receive a write request, the write request having an extent;
• apply a hash function to the extent to generate a hash table index and a hash table selector;
• select a cuckoo table from a plurality of cuckoo tables in the memory;
• store a portion of the hash table index in a slot of the selected cuckoo table, the slot including a location of the extent on the one or more SSDs;
• determine whether the slot has been written to a checkpoint;
• in response to determining that the slot has been written to the checkpoint, record the slot in a first log, wherein the log is written to the one or more SSDs, wherein the log is organized in reverse chronological order;
• and
• write an index table to the checkpoint, the index table including a location of a page having the slot on the one or more SSDs.