METADATA CONTAINERS WITH INDIRECT POINTERS

• US 20140189276A1
• Filed: 07/11/2013
• Published: 07/03/2014
• Est. Priority Date: 01/03/2013
• Status: Active Grant

• Current Assignee: Macronix International Co., Ltd.
• Original Assignee: Macronix International Co., Ltd.
• Inventors: Wang, Cheng-Yuan, Li, Hsiang-Pang, Chang, Yuan-Hao, Hsiu, Pi-Cheng, Kuo, Tei-Wei, Chang, Hung-Sheng
• Granted Patent: US 9,547,586 B2
• Time in Patent Office: Days
• US Class Current: 711/165
• CPC Class Codes: G06F 12/0238 Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/109 for multiple virtual address spaces, e.g. segmentation G06F12/1036 takes precedence
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 2212/1032 Reliability improvement, data loss prevention, degraded operation etc
• CPC Class Codes: G06F 2212/7204 Capacity control, e.g. partitioning, end-of-life degradation
• CPC Class Codes: G06F 2212/7211 Wear leveling

Abstract

A method is provided for managing a file system including data objects. The data objects, indirect pointers and source pointers are stored in containers that have addresses and include addressable units of a memory. The objects are mapped to addresses for corresponding containers. The indirect pointer in a particular container points to the address of a container in which the corresponding object is stored. The source pointer in the particular container points to the address of the container to which the object in the particular container is mapped. An object in a first container is moved to a second container. The source pointer in the first container is used to find a third container to which the object is mapped. The indirect pointer in the third container is updated to point to the second container. The source pointer in the second container is updated to point to the third container.

Claims

1. A method for memory management, comprising:

storing data objects in a plurality of containers having addresses;

mapping the data objects to addresses for corresponding containers in the plurality of containers; and

storing indirect pointers in the containers, the indirect pointer in a particular container pointing to the address of a container in the plurality of containers in which the corresponding data object is stored.

2. The method of claim 1, including storing source pointers in the containers, the source pointer in the particular container pointing to the address of the container in the plurality of containers to which the data object stored in the particular container is mapped.

3. The method of claim 1, including moving a data object stored in a first one of the containers to a second one of the containers, the data object being mapped to a third one of the containers, and using the source pointer in the first one to find the third one, updating the indirect pointer in the third one to point to the second one, and updating the source pointer in the second one to point to the third one.

4. The method of claim 1, including swapping a first data object stored in a first one of the containers with a second data object stored in a second one of the containers, the first data object being mapped to a third one of the containers and the second data object being mapped to a fourth one of the containers, using the source pointer in the first one to find the third one, using the source pointer in the second one to find the fourth one, updating the indirect pointer in the third one to point to the container that is pointed to by the indirect pointer of the fourth one, updating the indirect pointer in the fourth one to point to the container that was pointed to by the indirect pointer of the third one before the indirect pointer of the third one is updated, updating the source pointer in the second one to point to the third one, and updating the source pointer in the first one to point to the fourth one.

5. The method of claim 1 including finding a particular data object by accessing the corresponding container, and reading the indirect pointer to access the particular data object.

6. The method of claim 1, including moving data objects among the containers in the plurality of containers according to usage patterns in the memory without changing the mapping.

7. An apparatus, comprising:

a memory including a plurality of data objects; and

a memory controller coupled to the memory, including logic to store the data objects in a plurality of containers having addresses;

logic to map the data objects to addresses for corresponding containers in the plurality of containers; and

logic to store indirect pointers in the containers, the indirect pointer in a particular container pointing to the address of a container in the plurality of containers in which the corresponding data object is stored.

8. The apparatus of claim 7, wherein the memory controller includes logic to store source pointers in the containers, the source pointer in the particular container pointing to the address of the container in the plurality of containers to which the data object stored in the particular container is mapped.

9. The apparatus of claim 7, wherein the memory controller includes logic to move a data object stored in a first one of the containers to a second one of the containers, the data object being mapped to a third one of the containers;

logic to use the source pointer in the first one to find the third one;

logic to update the indirect pointer in the third one to point to the second one; and

logic to update the source pointer in the second one to point to the third one.

10. The apparatus of claim 7, wherein the memory controller includes logic to swap a first data object stored in a first one of the containers with a second data object stored in a second one of the containers, the first data object being mapped to a third one of the containers and the second data object being mapped to a fourth one of the containers;

logic to use the source pointer in the first one to find the third one, and to use the source pointer in the second one to find the fourth one;

logic to update the indirect pointer in the third one to point to the container that is pointed to by the indirect pointer of the fourth one, and to update the indirect pointer in the fourth one to point to the container that was pointed to by the indirect pointer of the third one before the indirect pointer of the third one is updated; and

logic to update the source pointer in the second one to point to the third one, and update the source pointer in the first one to point to the fourth one.

11. The apparatus of claim 7, wherein the memory controller includes logic to find a particular data object by accessing the corresponding container, and to read the indirect pointer to access the particular data object.

12. The apparatus of claim 7, wherein the memory controller includes logic to move data objects among the containers in the plurality of containers according to usage patterns in the memory without changing the mapping.

13. A method for memory management, comprising:

storing data objects in a plurality of containers having addresses and comprising addressable units of a physical memory;

using indirect pointers to access the data objects, the indirect pointer in a particular container pointing to the address of a container in the plurality of containers in which the corresponding data object is stored; and

moving the data objects and updating the indirect pointers according to a wear leveling protocol for the physical memory.

14. The method of claim 13, including storing the indirect pointers in the physical memory.

15. The method of claim 13, including storing the indirect pointers in the containers.