Data cloning in memory-based file systems

An apparatus comprising:

• a persistent storage retaining data units used by a file system, wherein a content of each object of the file system is retained in the data units, wherein the each object is represented using a tree of nodes comprising tree nodes and leaf nodes, wherein each tree node points to at least one node, wherein each leaf node of at least a portion of the leaf nodes points to a data unit used to retain content of the each object;
• wherein said persistent storage comprising a Byte-addressable persistent memory, wherein said Byte-addressable persistent memory is configured to retain at least a portion of the data units used by the file system, wherein said Byte-addressable persistent memory retaining the nodes;
• a processor, wherein said processor is configured to scan said Byte-addressable persistent memory to compile a volatile resource usage collection and volatile reference counters of the nodes;
• wherein said processor is configured, in response to a determination to reuse a pointed node of a tree of an object by a pointing node, to:
• update a volatile reference counter of the pointed node;
• and
• atomically set, by a single instruction, the pointing node to point to the pointed node.