US Patent 10983705 Handling pattern identifiers in a data storage system

Techniques for handling pattern identifiers in a data storage system. By replacing a block pointer with a pattern identifier, the techniques can identify a data block (or an indirect data block) as a bad block, without resorting to the use of a separate flag or bad block (BB) bit in per-block metadata (e.g., a mapping pointer) of the data block. The techniques can also avoid waste of valuable metadata space by using pattern identifiers at various levels of a mapping tree, leveraging pointer granularity at lower levels, mid-levels, and progressively higher levels of the mapping tree.