Reusing overwritten portion of write buffer of a storage system

Patent metadata

Field	Value
Publication number	US-11269547-B2
Application number	US-202016879459-A
Country	US
Kind code	B2
Filing date	May 20, 2020
Priority date	May 20, 2020
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

An apparatus comprises at least one processing device comprising a processor coupled to a memory. The at least one processing device is configured to receive a write command at a control module of a storage system, wherein the write command comprises a write operation configured to cause one or more data pages in a page buffer associated with the control module to be overwritten with incoming data. The at least one processing device is also configured to invalidate the one or more overwritten data pages in the page buffer after committing the write operation. The at least one processing device is further configured to release the one or more invalidated data pages in the page buffer to a page buffer pool associated with the control module, wherein the page buffer pool manages available data pages in the page buffer.

First claim

What is claimed is:

1. An apparatus comprising:
at least one processing device comprising a processor coupled to a memory;
the at least one processing device being configured to:
receive a write command at a control module of a storage system, wherein the write command comprises a write operation configured to cause one or more data pages in a page buffer associated with the control module to be overwritten with incoming data;
invalidate the one or more overwritten data pages in the page buffer after committing the write operation; and
release the one or more invalidated data pages in the page buffer to a page buffer pool associated with the control module, wherein the page buffer pool manages available data pages in the page buffer, and wherein the page buffer pool is configured as a data structure with one or more nodes, and wherein each node of the one or more nodes specifies a segment of continuous data pages available in the page buffer.

2. The apparatus of claim 1 , wherein the at least one processing device is further configured to:
receive a subsequent write command at the control module; and
reuse at least a portion of the one or more released data pages managed by the page buffer pool to process the subsequent write command.

3. The apparatus of claim 1 , wherein the at least one processing device is further configured to:
determine that one or more data pages in the page buffer is associated with a storage snapshot creation; and
persist the one or more data pages associated with the storage snapshot creation when the received write command comprises a write operation that would otherwise cause the one or more data pages associated with the storage snapshot creation to be overwritten.

4. The apparatus of claim 1 , wherein each node of the one or more nodes specifies information comprising a starting page index of the segment, an ending page index of the segment, and a number of pages in the segment.

5. The apparatus of claim 4 , wherein the at least one processing device is further configured to update the information in a given one of nodes when a data page is released to or allocated from the given one of the nodes.

6. The apparatus of claim 1 , wherein the at least one processing device is further configured to allocate continuous pages from a given one of the nodes of the page buffer pool.

7. The apparatus of claim 6 , wherein the at least one processing device is further configured to allocate one or more additional pages from at least another given one of the nodes of the page buffer pool when there are insufficient pages specified in the given one of the nodes.

8. The apparatus of claim 7 , wherein one or more of the one or more additional pages from the at least other given one of the nodes are continuous with respect to the continuous pages from the given one of the nodes.

9. The apparatus of claim 7 , wherein one or more of the one or more additional pages from the at least other given one of the nodes are not continuous with respect to the continuous pages from the given one of the nodes.

10. The apparatus of claim 1 , wherein the at least one processing device is further configured to allocate pages from a given one of the nodes of the page buffer pool using an allocation pointer.

11. The apparatus of claim 1 , wherein the at least one processing device is further configured to allocate pages from a given one of the nodes of the page buffer pool by determining a best fit segment.

12. The apparatus of claim 1 , wherein the at least one processing device is further configured to allocate pages from two or more nodes of the nodes of the page buffer pool.

13. The apparatus of claim 1 , wherein the at least one processing device is further configured to release the one or more invalidated data pages in the page buffer to the page buffer pool by creating an additional node in the page buffer pool and inserting the one or more released data pages into the additional node.

14. The apparatus of claim 1 , wherein the at least one processing device is further configured to release the one or more invalidated data pages in the page buffer to the page buffer pool by merging the one or more released data pages into an existing node in the page buffer pool.

15. The apparatus of claim 1 , wherein the at least one processing device is further configured to perform a replay operation during a recovery of the storage system in accordance with the page buffer pool.

16. 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 the at least one processing device to perform steps of:
receiving a write command at a control module of a storage system, wherein the write command comprises a write operation configured to cause one or more data pages in a page buffer associated with the control module to be overwritten with incoming data;
invalidating the one or more overwritten data pages in the page buffer after committing the write operation; and
releasing the one or more invalidated data pages in the page buffer to a page buffer pool associated with the control module, wherein the page buffer pool manages available data pages in the page buffer, wherein the page buffer pool is configured as a data structure with one or more nodes, and wherein each node of the one or more nodes specifies a segment of continuous data pages available in the page buffer.

17. The computer program product of claim 16 , wherein the program code when executed by at least one processing device further causes the at least one processing device to perform steps of:
receiving a subsequent write command at the control module; and
reusing at least a portion of the one or more released data pages managed by the page buffer pool to process the subsequent write command.

18. The computer program product of claim 16 , wherein the program code when executed by at least one processing device further causes the at least one processing device to perform steps of:
determining that one or more data pages in the page buffer is associated with a storage snapshot creation; and
persisting the one or more data pages associated with the storage snapshot creation when the received write command comprises a write operation that would otherwise cause the one or more data pages associated with the storage snapshot creation to be overwritten.

19. A method comprising steps of:
receiving a write command at a control module of a storage system, wherein the write command comprises a write operation configured to cause one or more data pages in a page buffer associated with the control module to be overwritten with incoming data;
invalidating the one or more overwritten data pages in the page buffer after committing the write operation; and
releasing the one or more invalidated data pages in the page buffer to a page buffer pool associated with the control module, wherein the page buffer pool manages available data pages in the page buffer, wherein the page buffer pool is configured as a data structure with one or more nodes, and wherein each node of the one or more nodes specifies a segment of continuous data pages available in the page buffer.

20. The method of claim 19 , further comprising steps of:
receiving a subsequent write command at the control module; and
reusing at least a portion of the one or more released data pages managed by the page buffer pool to process the subseq

Assignees

• Emc Ip Holding Co Llc

Inventors

• Liu Yousheng
• Heng Socheavy D
• Xu Xinlei
• Han Geng
• Gao Jian

Classifications

• G06F2212/7203

  Temporary buffering, e.g. using volatile buffer or dedicated buffer blocks · CPC title

• G06F12/0246

  in block erasable memory, e.g. flash memory · CPC title

• G06F3/067 Primary

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F3/0656 Primary

  Data buffering arrangements · CPC title

• G06F3/064

  Management of blocks · CPC title