Method and device for data read and write

Patent metadata

Field	Value
Publication number	US-10969966-B2
Application number	US-201916684249-A
Country	US
Kind code	B2
Filing date	Nov 14, 2019
Priority date	Jun 2, 2017
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

Embodiments of the present disclosure relate to method and device for data read/write. The method comprises: in response to receiving a first read/write request for a first target area, determining whether there is a second read/write request under execution in conflict with the first read/write request, a second target area for the second read/write request at least partially overlapping with the first target area, and at least one of the first read/write request and the second read/write request being a write request; and in response to determining there being the second read/write request in conflict, suspending the first read/write request while maintaining a sub-area of the first target area in an unlocked state, the sub-area not overlapping with the second target area.

First claim

We claim:

1. A method for managing write requests, comprising:
in response to receiving a first write request for a file system, splitting the first write request into a first set of sub-requests;
in response to receiving a second write request for the file system, splitting the second write request into a second set of sub-requests; and
in response to detecting that a first sub-request of the first set of sub-requests and a second sub-request of the second set of sub-requests are contiguous in a storage area of the file system, merging the first sub-request with the second sub-request for writing,
wherein the first write request and the second write request are directed to respective ranges of the storage area of the file system, the storage area including logic data units of uniform size, and
wherein splitting the first write request into the first set of sub-requests is performed (i) at a first boundary between a first logic data unit and a second logic data unit, and (ii) at a second boundary between the second logic data unit and a third logic data unit.

2. The method of claim 1 , wherein merging the first sub-request with the second sub-request forms an area in the storage area that does not cross any boundary between adjacent logic data units.

3. The method of claim 1 , further comprising:
in response to receiving a third write request that occupies an entire logic data unit of the logic data units, executing the third write request without splitting or merging the third write request with any other write request or sub-request.

4. The method of claim 1 , wherein splitting the first write request into the first set of sub-requests is performed in response to the first write request specifying data that extends across a boundary between adjacent logic data units.

5. The method of claim 4 , wherein merging the first sub-request with the second sub-request includes combining the first sub-request and the second sub-request in an area that does not cross any boundary between adjacent logic data units.

6. The method of claim 1 , wherein the first, second, and third logic data units each include respective portions of data specified by the first write request.

7. The method of claim 6 , further comprising:
in response to receiving a third write request for a file system, splitting the third write request into a third set of sub-requests; and
in response to detecting that a third sub-request of the third set of sub-requests and a fourth sub-request of the first set of sub-requests are contiguous in the storage area, merging the third sub-request with the fourth sub-request for writing.

8. A computerized system, comprising control circuitry that includes a set of processing units coupled to memory, the control circuitry constructed and arranged to:
in response to receiving a first write request for a file system, split the first write request into a first set of sub-requests;
in response to receiving a second write request for the file system, split the second write request into a second set of sub-requests; and
in response to detecting that a first sub-request of the first set of sub-requests and a second sub-request of the second set of sub-requests are contiguous in a storage area of the file system, merge the first sub-request with the second sub-request for writing,
wherein the first write request and the second write request are directed to respective ranges of the storage area of the file system, the storage area including logic data units of uniform size, and
wherein the control circuitry is constructed and arranged to split the first write request into the first set of sub-requests (i) at a first boundary between a first logic data unit and a second logic data unit, and (ii) at a second boundary between the second logic data unit and a third logic data unit.

9. The computerized system of claim 8 , wherein the control circuitry is further constructed and arranged to merge the first sub-request with the second sub-request to form an area in the storage area that does not cross any boundary between adjacent logic data units.

10. The computerized system of claim 8 , wherein the control circuitry is further constructed and further arranged to:
in response to receiving a third write request that occupies an entire logic data unit of the logic data units, execute the third write request without splitting or merging the third write request with any other write request or sub-request.

11. The computerized system of claim 8 , wherein the control circuitry is further constructed and further arranged to:
split the first write request into the first set of sub-requests in response to the first write request specifying data that extends across a boundary between adjacent logic data units.

12. A computer program product including a set of non-transitory, computer-readable media having instructions which, when executed by control circuitry of a computerized system, cause the control circuitry to perform a method of managing write requests, the method comprising:
in response to receiving a first write request for a file system, splitting the first write request into a first set of sub-requests;
in response to receiving a second write request for the file system, splitting the second write request into a second set of sub-requests; and
in response to detecting that a first sub-request of the first set of sub-requests and a second sub-request of the second set of sub-requests are contiguous in a storage area of the file system, merging the first sub-request with the second sub-request for writing,
wherein the first write request and the second write request are directed to respective ranges of the storage area of the file system, the storage area including logic data units of uniform size, and
wherein splitting the first write request into the first set of sub-requests is performed (i) at a first boundary between a first logic data unit and a second logic data unit, and (ii) at a second boundary between the second logic data unit and a third logic data unit.

13. The computer program product of claim 12 , wherein merging the first sub-request with the second sub-request forms an area in the storage area that does not cross any boundary between adjacent logic data units.

14. The computer program product of claim 12 , wherein the method further comprises:
in response to receiving a third write request that occupies an entire logic data unit of the logic data units, executing the third write request without splitting or merging the third write request with any other write request or sub-request.

15. The computer program product of claim 12 , wherein splitting the first write request into the first set of sub-requests is performed in response to the first write request specifying data that extends across a boundary between adjacent logic data units.

16. The computer program product of claim 12 , wherein the first, second, and third logic data units each include respective portions of data specified by the first write request.

17. The computer program product of claim 16 , wherein the method further comprises:
in response to receiving a third write request for a file system, splitting the third write request into a third set of sub-requests; and
in response to detecting that a third sub-request of the third set of sub-requests and a fourth sub-request of the first set of sub-requests are contiguous in the storage area, merging the third sub-request with the fourth sub-request for writing.

Assignees

• Emc Ip Holding Co Llc

Inventors

• Zhao Bean Bin
• Hu Wilson Guoyu
• Wu Jun
• Lv Shuo
• Zhou Qiaosheng
• Zhang Lester Ming

Classifications

• G06F3/0659

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title

• G06F16/1767

  Concurrency control, e.g. optimistic or pessimistic approaches · CPC title

• G06F3/0611 Primary

  in relation to response time · CPC title

• G06F3/0613

  in relation to throughput · CPC title

• G06F9/526 Primary

  Mutual exclusion algorithms · CPC title