System and method for providing a unified storage system that supports file/object duality

• US 9,400,802 B2
• Filed: 05/01/2015
• Issued: 07/26/2016
• Est. Priority Date: 06/24/2011
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Slik, David
• Primary Examiner(s): ALAM, SHAHID AL
• Application Number:
  US14/702,559
• Publication Number:
  US 20150234815A1
• Time in Patent Office: 452 Days
• Field of Search: 707/609, 707/695, 707/781, 707/782, 707/626
• US Class Current: 1/1
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files
• CPC Class Codes: G06F 16/1824 implemented using Network-attached Storage [NAS] architecture distributed or networked storage systems G06F3/067; protocols for distributed storage of data in a network H04L67/1097
• CPC Class Codes: G06F 16/1827 Management specifically adapted to NAS management of storage area networks [SAN] G06F3/067
• CPC Class Codes: G06F 16/196 Specific adaptations of the file system to access devices and non-file objects via standard file system access operations, e.g. pseudo file systems dedicated interfaces to storage systems G06F3/0601
• CPC Class Codes: G06F 16/2308 Concurrency control transaction processing G06F9/466
• CPC Class Codes: G06F 16/2336 Pessimistic concurrency control approaches, e.g. locking or multiple versions without time stamps
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: G06F 16/951 Indexing; Web crawling techniques
• CPC Class Codes: G06F 16/972 Access to data in other repository systems, e.g. legacy data or dynamic Web page generation
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

Methods and systems that permit file protocols and object protocols to co-exist using a file namespace and an object namespace in a unified storage system are disclosed. Data stored in the unified storage system are file-objects that preserve the behaviors expected by both file clients and object clients.

Claims

1. A method for updating file objects based on modifications to file representations of data entities, said method comprising:

generating a file representation of a data entity in a storage system;

generating a first object representation of the data entity in the storage system;

generating a first object namespace redirector that includes a pointer to the first object representation;

generating a file namespace redirector that includes a pointer to the file representation and a pointer to the first object namespace redirector; and

if the file representation has been modified,

copying data content of the modified file representation to a second object representation;

generating a second object namespace redirector that includes a pointer to the second object representation; and

modifying the first object namespace redirector pointer to point to the second object namespace redirector.

2. The method of claim 1, wherein said copying comprises cloning.

3. The method of claim 1, further comprising waiting until a holdoff period expires prior to copying data content of the modified file representation to the second object representation.

4. The method of claim 1, further comprising:

if the object representation has been modified and if the file representation is locked for writing, waiting until a write lock on the file representation is released prior to copying data content of the modified object representation to update the file representation.

5. The method of claim 1, further comprising:

allocating object identifiers (OIDs) for each of multiple, sequential historical versions of the object representation; and

associating the OIDs with respective object namespace redirectors.

6. A method for providing access to consistent object and file representations of data entities in a storage system, said method comprising:

creating and storing a first representation of a data entity in a storage system;

creating and storing a second representation of the data entity in the storage system;

wherein a first namespace is used by a first protocol to locate the first representation, and a second namespace is used by a second protocol to locate the second representation;

creating a first namespace redirector in the first namespace, wherein the first namespace redirector includes a pointer to the first representation;

creating a second namespace redirector in the second namespace, wherein the second namespace redirector includes a pointer to the second representation and a pointer to the first namespace redirector; and

modifying the first object namespace redirector pointer to point to the second object namespace redirector.

7. The method of claim 6, further comprising:

in an event that the first representation has been modified, copying the modified first representation to update the second representation; and

in an event that the second representation has been modified, copying the modified second representation to update the first representation, and

wherein modifications made via the first protocol are accessible via the second protocol, and modifications made via the second protocol are accessible via the first protocol.

8. The method of claim 7, further comprising waiting until a holdoff period expires for the first representation prior to copying the second representation to update the first representation.

9. The method of claim 7, further comprising in an event that the second representation is locked for writing, waiting until a write lock on the second representation is released prior to copying the modified first representation to update the second representation.

10. The method of claim 6, further comprising:

creating a third namespace redirector in the first namespace to point to a previous version of the first representation, wherein, when the first representation is modified, an unmodified version of the first representation is retained as the previous version.

11. The method of claim 10, further comprising:

allocating identifiers for the first representation and each of multiple previous versions of the first representation; and

associating the identifiers with the respective first namespace redirectors.

12. One or more non-transitory machine-readable storage media having program code for updating file objects based on modifications to file representations of data entities stored therein, the program code to:

generate a file representation of a data entity in a storage system;

generate a first object representation of the data entity in the storage system;

generate a first object namespace redirector that includes a pointer to the first object representation;

generate a file namespace redirector that includes a pointer to the file representation and a pointer to the first object namespace redirector; and

if the file representation has been modified,

copy data content of the modified file representation to a second object representation;

generate a second object namespace redirector that includes a pointer to the second object representation; and

modify the first object namespace redirector pointer to point to the second object namespace redirector.

13. The machine-readable storage media of claim 12, wherein the program code to copy comprises program code to clone.

14. The machine-readable storage media of claim 12, further comprising program code to wait until a holdoff period expires prior to copying data content of the modified file representation to the second object representation.

15. The machine-readable storage media of claim 12, further comprising program code to:

if the object representation has been modified, and in an event that the file representation is locked for writing, wait until a write lock on the file representation is released prior to copying data content of the modified object representation to update the file representation.

16. The machine-readable storage media of claim 12, further comprising program code to:

allocate object identifiers (OIDs) for each of multiple, sequential historical versions of the object representation; and

associate the OIDs with respective object namespace redirectors.