Data storage system with repair of virtual data blocks of internal file system

A data storage system having processing circuitry defining and using an internal file system, the processing circuitry being configured and operative to store and execute computer program instructions to perform a method of repairing an indirect addressing structure of the file system that has been damaged by corruption of a virtual data block (VDB) providing indirection for file system data stored in corresponding physical data blocks (PDBs), the method including:

• scanning PDB descriptors to identify PDBs storing file system data mapped by the corrupted VDB, each identified PDB including a set of PDB entries each having a corresponding backward pointer identifying a corresponding VDB entry of a corresponding VDB;
• scanning the identified PDBs to identify PDB entries whose backward pointers refer to VDB entries of the corrupted VDB;
• creating a replacement VDB by (1) for each of the identified PDB entries, recreating a corresponding VDB entry including a forward pointer to the identified PDB entry, and (2) incorporating the recreated VDB entries into the replacement VDB;
• and
• incorporating the replacement VDB into the indirect addressing structure in place of the corrupted VDB.