Snapshot-enabled storage system implementing algorithm for efficient reading of data from stored snapshots

A method comprising:

• maintaining a snapshot tree data structure having a plurality of volume nodes corresponding to respective ones of (i) a root volume and (ii) multiple snapshots related directly or indirectly to the root volume;
• receiving a request to read a data item from a given volume offset of a particular one of the volume nodes;
• determining a set of data descriptors for the given volume offset;
• determining a set of volume nodes of interest for the particular volume node;
• determining a contribution set based at least in part on the set of data descriptors and the set of volume nodes of interest;
• determining a read address for the data item as a function of the contribution set;
• and
• reading the data item from the read address;
• wherein determining the contribution set comprises identifying a particular subset of the set of data descriptors based at least in part on time values of one or more data items and time values of one or more volume nodes, a first one of the data items having a first time value indicating a time at which the data item was written in a snapshot corresponding to a first one of the volume nodes;
• and
• wherein the method is performed by at least one processing device comprising a processor coupled to a memory.

A computer program product comprising a non-transitory processor-readable storage medium having stored therein program code of one or more software programs, wherein the program code when executed by at least one processing device causes said at least one processing device:

• to maintain a snapshot tree data structure having a plurality of volume nodes corresponding to respective ones of (i) a root volume and (ii) multiple snapshots related directly or indirectly to the root volume;
• to receive a request to read a data item from a given volume offset of a particular one of the volume nodes;
• to determine a set of data descriptors for the given volume offset;
• to determine a set of volume nodes of interest for the particular volume node;
• to determine a contribution set based at least in part on the set of data descriptors and the set of volume nodes of interest;
• to determine a read address for the data item as a function of the contribution set;
• and
• to read the data item from the read address;
• wherein determining the contribution set comprises identifying a particular subset of the set of data descriptors based at least in part on time values of one or more data items and time values of one or more volume nodes, a first one of the data items having a first time value indicating a time at which the data item was written in a snapshot corresponding to a first one of the volume nodes.