Generalized storage virtualization interface

A computer-implemented storage system, comprising:

• means for storing data blocks on a physical storage resource, wherein storing the data blocks comprises maintaining logical-to-physical mappings to associate the stored data blocks with identifiers of a logical address space;
• means for requesting designated modifications to logical-to-physical mappings, comprising an API function for requesting a merge modification to the logical-to-physical mappings pertaining to specified identifiers;
• and
• means for implementing a merge modification to the logical-to-physical mappings in response to a request specifying a first set of identifiers and a second set of identifiers by modifying the logical-to-physical mappings to combine the first set of identifiers and the second set of identifiers into a third set of identifiers,
• wherein:
• the logical-to-physical mappings are modified to associate each identifier of the third set of identifiers with a stored data block associated with an identifier selected from one of the first set of identifiers and the second set of identifiers in accordance with a merge policy specified by the client,
• the merge policy specifies rules to resolve merge conflicts based on differences in logical address vectors for the first set identifiers and the second set of identifiers, and
• the means for storing the data blocks, the means for requesting the designated modifications, and the means for implementing the merge modification comprise one or more of a set of hardware circuits, a set of programmable hardware devices, and executable code stored on a set of non-transitory computer-readable storage media.

A method, comprising:

• maintaining persistent metadata comprising mappings between data segments stored on a storage resource and identifiers of a front-end address space, the front-end address space used by clients to access the stored data segments through a data storage interface;
• and
• providing a logical manipulation interface operating on a computing device to receive requests to manipulate specified mappings of the persistent metadata, wherein receiving a request comprises:
• receiving a designation of a manipulation operation for the request, the manipulation operation being designated from a plurality of manipulation operations available to the clients through the logical manipulation interface, including a merge operation;
• and
• specifying identifiers of the front-end address space for the designated manipulation operation;
• receiving a first request that designates a merge operation, designates a merge policy among a plurality of merge policies specified by the client in the request, and specifies a first plurality of front-end identifiers and a second plurality of identifiers,
• wherein:
• implementing the first request comprises:
• combining the first plurality of front-end identifiers with the second plurality of front-end identifiers, the combining comprising modifying the persistent metadata to associate each identifier of a third set of front-end identifiers with a stored data segment associated with an identifier of one of the first set of front-end identifiers and the second set of front-end identifiers in accordance with the designated merge policy, and
• the merge policy specifies rules to resolve merge conflicts based on differences in logical address vectors for the first set of front-end identifiers and the second set of front-end identifiers.

An apparatus, comprising:

• a non-transitory, non-volatile storage medium;
• a client configured to issue storage requests to a storage layer through a storage interface, the storage interface corresponding to a logical address space, wherein the storage requests comprise requests to store data associated with respective addresses of the logical address space on the non-volatile storage medium,
• wherein:
• the storage layer is configured to:
• maintain translation data comprising logical-to-physical associations between data stored on the non-volatile storage medium and addresses of the logical address space, and
• make logical manipulation primitives available to the client, each logical manipulation primitive configured for requesting implementation of designated manipulation operations pertaining to specified logical-to-physical associations of the translation data,
• the client is configured to implement storage management operations by use of the logical manipulation primitives made available by the storage layer,
• the storage layer is further configured to, in response to a client request to implement a merge operation specifying a first set of addresses and a second set of addresses, modify the translation data to merge logical-to-physical associations of the first set of addresses with logical-to-physical associations of the second set of addresses, each of the merged logical-to-physical associations being associated with stored data corresponding to a logical-to-physical association of one of the first set of addresses and the second set of addresses in accordance with a merge policy specified in the client request, and
• the merge policy specifies rules to resolve merge conflicts based on differences in logical address vectors for the first set of addresses and the second set of addresses.