WO2015055020A1

WO2015055020A1 - Method and apparatus for writing data

Info

Publication number: WO2015055020A1
Application number: PCT/CN2014/080509
Authority: WO
Inventors: 龚涛; 梁剑
Original assignee: 华为技术有限公司
Priority date: 2013-10-18
Filing date: 2014-06-23
Publication date: 2015-04-23
Also published as: CN103513941A; CN103513941B

Abstract

A method and apparatus for writing data, the method comprising: determining in a cache a first valid data block comprising a plurality of contiguous valid sectors where data is saved; determining in the first valid data block a second valid data block referring to a valid data block containing dirty sectors; determining in the second valid data block a target valid data block containing a plurality of pages, wherein any page contains dirty data; and writing the data in the target valid data block into a solid state disk (SSD). The number of clean sectors written into the SSD is reduced as much as possible, and therefore the volume of data written into the SSD is reduced to prolong the service life of the SSD.

Description

Method and device for writing data

This application is submitted to the Chinese Patent Office on October 18, 2013, and the application number is

201310495179.8, the entire disclosure of which is incorporated herein by reference in its entirety in its entirety in its entirety in the the the the the the the the the

TECHNICAL FIELD The present invention relates to communications technologies, and in particular, to a method and apparatus for writing data. Background technique

The current Solid State Device (SSD) is basically a flash-based medium. Inside an SSD, there are multiple flash granules. Each flash granule is internally divided into several blocks. Each block consists of blocks. Divided into several pages. Flash media cannot convert 0/1 bits to any bit (Wt) bits, and can only be erased and programmed with a certain granularity. The erased granularity is a block, which means that all the Wt bits in the specified block are set to 1; the programmed granularity is a page, which means that the bit specified in the page is set to 0. The page is the minimum granularity for reading and writing inside the SSD, but the SSD is compatible with the hard disk drive (HDD). The interface provided by the SSD is granular by the sector.

In the prior art, the process of writing data to the SSD by the host is as follows: The data to be written by the host is first given to the storage array, and the storage array sends the data to the cache in the storage array, and the cache sends the response to the host. Write to the SSD. If the size of the data given by the host to the storage array is less than the size of one page, the cache can perform a fill, that is, fill the size of one page and then write to the hard disk.

However, with the prior art, due to the difference between the internal read/write granularity of the SSD and the external access granularity, the SSD may have a problem of excessive write penalty and write amplification times. Specifically, for the write request of the host, the above cache is completed. The process is called "write penalty"; write amplification means that the amount of data written to the flash memory is greater than the amount of data written to the SSD, and the write penalty is a special write amplification. There are other reasons that can cause write amplification, such as writing data to an SSD without following the "page" of the flash. Align, it will be filled in and then written to the flash at the granularity of the page. That is to say, the use of the prior art will increase the amount of data written to the SSD, thereby reducing the useful life of the SSD. Summary of the invention

Embodiments of the present invention provide a method and apparatus for writing data, which are used to solve the problem of increasing the amount of data written into an SSD due to too many write amplification and write penalty times.

A first aspect of the embodiments of the present invention provides a method for writing data, where the method is applied to a storage device, where the storage device includes a controller and a solid state hard disk, and the controller includes a cache, the cache Include multiple pages, each page including multiple sectors, the method includes:

Determining, in the cache, a first valid data block, the first valid data block includes a plurality of consecutive valid sectors, and the valid sector holds data;

Determining a second valid data block in the first valid data block, where the second valid data block refers to a valid data block including a dirty sector;

Determining a target valid data block in the second valid data block, where the target valid data block includes a plurality of pages, wherein any one of the pages includes a dirty sector;

The data in the target valid data block is written to the solid state hard disk.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the determining, by the cache, the first valid data block includes:

Traversing all sectors of the cache in a predetermined designated area;

A maximum contiguous valid data block is obtained as the first valid data block, the first valid data block including a maximum of consecutive valid sectors.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the dirty sector includes data to be written to a solid state hard disk, where the clean sector includes Write data to the solid state drive.

A second aspect of the embodiments of the present invention provides an apparatus for writing data, where the storage device includes a controller and a solid state hard disk, the controller includes a cache, and the cache includes a plurality of pages, and each page includes Multiple sectors, including:

a determining module, configured to determine a first valid data block in the cache, the first valid data block includes a plurality of consecutive valid sectors, and the wired sector holds data; Determining a second valid data block in the valid data block, the second valid data block refers to a valid data block including a dirty sector; determining a target valid data block in the second valid data block, the target valid data block Contains multiple pages, any of which contains dirty sectors;

And a write module, configured to write data in the target valid data block to the solid state hard disk.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the determining module is specifically configured to: traverse all sectors of the preset designated area in the buffer; and obtain a maximum continuous valid data block as The first valid data block includes the most consecutive valid sectors in the first valid data block.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, the dirty sector includes data to be written to the solid state hard disk, where the clean sector includes Write data to the solid state drive.

In the embodiment of the present invention, the first valid data block including the consecutive effective sectors is determined in the cache, and then the valid data block including the dirty sector is determined in the first valid data block, and finally determined in the second valid data block. Target data block, each page contained in the target data block has a dirty sector, and the target data block is written into the SSD, thereby reducing the clean sectors written in the SSD as much as possible, thereby reducing the write SSD The amount of data has been extended to extend the life of the SSD. Appendix

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, a brief description of the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

1 is a schematic flowchart of Embodiment 1 of a method for writing data according to the present invention;

2 is a schematic diagram of a sector structure of a method for writing data according to a second embodiment of the present invention; FIG. 3 is a schematic diagram of a sector structure of a method for writing data according to a third embodiment of the present invention; FIG. 5 is a schematic diagram of a sector structure of a method for writing data according to Embodiment 5 of the present invention; FIG. 6 is a schematic diagram of a structure of a device for writing data according to Embodiment 1 of the present invention; Schematic;

FIG. 7 is a schematic structural diagram of Embodiment 1 of a storage device according to the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The embodiment of the present invention is applied to a storage device, where the storage device includes a controller and an SSD. The controller includes a cache, and the cache further includes a plurality of pages, and each page includes multiple sectors. If the data is stored in the sector, the sector is a valid sector, and if no data is saved, it is an invalid sector. In the embodiment of the present invention, the effective sector includes a dirty sector and a clean sector, wherein the dirty sector includes data to be written to the SSD, and the clean sector includes data that has been written into the SSD.

1 is a schematic flowchart of a first embodiment of a method for writing data according to the present invention. FIG. 2 is a schematic structural diagram of a sector of a method for writing data according to a second embodiment of the present invention. As shown in FIG. 1, the method includes:

S101. Determine a first valid data block in the cache. The first valid data block includes a plurality of consecutive valid sectors in which data is stored. The cache contains a large number of sectors, which can divide a continuous effective sector into a valid data block, and one or more first valid data blocks can be determined in the cache.

Specifically, the dirty sector indicates that the data in the sector is actually written to the SSD, and the data in the dirty sector is different from the current data in the corresponding location in the SSD, and the dirty sector cannot be written new before being erased. The data. The data in the clean sector is the data read by the host from the SSD, and is left in the cache, so the data in the clean sector is the same as the data in the corresponding location in the SSD. Both dirty and clean sectors are valid sectors. The invalid sector can be a blank sector without any content, that is, the host does not read the data of the corresponding sector from the SSD, and there is currently no data in the invalid sector in the cache. The determined first valid data block does not contain an invalid sector.

As shown in Figure 2, suppose a page contains 8 sectors, where each square represents a sector, blank squares indicate clean sectors, and "twill" shaded squares indicate dirty sectors, "dot" The shaded squares indicate invalid sectors, the 8 sectors of ml-m8 represent one page, and the 8 sectors of nl-n8 represent another page, which are two consecutive pages in the SSD. It can be seen that m5-n3 continuous sector structure The resulting data block M contains seven consecutive valid data blocks, wherein there are no invalid sectors, which can be determined as the first valid data block.

5102. Determine a second valid data block in the first valid data block, where the second valid data block refers to a valid data block that includes a dirty sector.

That is, if a plurality of first valid data blocks are determined in S101, the first valid data block in which the dirty sector is not included is culled, and the remaining first valid data block is taken as the second valid data block.

5103. Determine a target valid data block in the second valid data block. The target valid data block contains multiple pages, any of which contains dirty sectors.

Each of the foregoing second valid data blocks may include a plurality of pages. If there are pages in the plurality of pages in which all sectors are clean sectors, such pages are removed from the second valid data block to form The new valid data block is used as the target valid data block, so that each page contained in the target valid data block contains dirty sectors.

5104. Write data in the target data block to the SSD.

In this embodiment, at least one first valid data block is determined in the cache, and then the first valid data block containing only the clean sector is removed, and then the page containing only the clean sector is removed, and finally the target data block is obtained. The target data block is written to the SSD, which reduces the clean sectors written into the SSD as much as possible, thereby reducing the amount of data written to the SSD and realizing the extended service life of the SSD.

3 is a schematic diagram of a sector structure of a method for writing data according to a third embodiment of the present invention, and FIG. 4 is a schematic diagram of a sector structure of a method for writing data according to a fourth embodiment of the present invention. FIG. A schematic diagram of the sector structure of the fifth embodiment of the method for entering data. As shown in FIG. 3, FIG. 4, and FIG. 5, for six consecutive pages, it is assumed that one page contains eight sectors, wherein each square represents one sector, and the blank square represents a clean sector, "twill "The shaded squares represent dirty sectors, and the "dot" shaded squares indicate invalid sectors.

Further, the foregoing determining the first valid data block in the cache is: traversing all the sectors of the preset designated area in the cache; acquiring the largest continuous valid data block as the first valid data block, the maximum continuous validity The data block includes the most consecutive valid sectors. The largest contiguous block of data here refers to including as many valid sectors as possible.

It should be noted that the capacity of the cache is generally large. To reduce the management overhead, the cache does not directly manage the page or sector, but manages a larger granularity. For example, it can manage a page group (page group). ), the above preset designated area refers to the page selected by the preset algorithm. Grou

For example, as shown in FIG. 3, the designated area is six consecutive pages as shown in FIG. 3. First, the 48 sectors are traversed, and three largest consecutive valid data blocks are obtained as the first valid data block. , are data blocks A, B, and C, respectively. Data block A includes a total of 4 sectors of a3-a6, data block B includes a total of 20 a8-d3, and data block C includes a total of 19 sectors of d6-f8. The 3 first valid data blocks are all included in the most consecutive valid sectors, and there are no invalid sectors. Then, the second valid data block is determined in the three first valid data blocks, that is, the data blocks in which all sectors in the three largest consecutive valid data blocks are clean sectors are culled, that is, the data block A is culled because a3 -a6 are all clean sectors. As shown in Figure 4, the remaining data blocks B and C are the second valid data blocks, and the data blocks B and C contain dirty sectors. Further processing the second valid data blocks B and C, processing in units of pages, culling pages in which all sectors in the second valid data block are clean sectors, and data blocks B and C spanning multiple pages As shown in FIG. 4, the data block B spans 4 pages. In the first page a-a8, only a8 belongs to the data block B, a8 is a clean sector, and a8 is eliminated, and the second page cl- C8 is a clean sector, and the entire page of cl-c8 is deleted to obtain the target data block. As shown in FIG. 5, after processing, the original data block B is now cut into data block D and data block £. Similarly, block C spans 3 pages, but the portions of the 3 pages spanned contain dirty sectors, d8 in d6-d8 is dirty, and el in el-e8 is dirty, fl- In f8, fl, f2, β, and f8 are dirty sectors, and the resulting target continuous valid data block F is the same as the data block C, that is, the sector in the data block C is not culled. The target data blocks thus determined are data blocks D, E, and F, and finally the data in data blocks D, E, and F are written to the SSD.

It should be noted that each data block generates an input/output (Input/Output, I/O for short) when writing to the SSD. In the embodiment of the present invention, an I/O indicates a write request or a read request.

For the preset designated area in the cache, for example, the preset designated area shown in FIG. 3, if the prior art is used, one can simply write the dirty sector directly to the SSD, so that five I/ are generated. O: Write b6 to SSD to generate an I/O, write d2 to SSD to generate an I/O, write d8-el to SSD to generate an I/O, and write fl-β to SSD to generate an I/O. Write f8-write to SSD to generate a 1/0, and these 5 I/Os need to be filled when writing to SSD, which will generate write penalty. The two I/Os of d2 and d8-el may be written. The SSD generates unnecessary junk pages, which will cause write amplification. Similarly, the two I/Os of fl-β and f8 will also generate write amplification. In this embodiment, the clean sectors written in the SSD are reduced as much as possible, and the write amplification and the write penalty are reduced, thereby reducing the amount of data written into the SSD, thereby realizing the extension of the service life of the SSD, and also Reduce I/O generation and reduce overall overhead.

FIG. 6 is a schematic structural diagram of Embodiment 1 of a device for writing data according to the present invention. In the device application and storage device, the storage device includes a controller and a solid state hard disk, and the controller includes a cache, and the cache includes multiple pages. Each page includes multiple sectors. As shown in FIG. 6, the apparatus includes: a determining module 601 and a writing module 602, wherein:

a determining module 601, configured to determine a first valid data block in the cache, the first valid data block includes a plurality of consecutive valid sectors, the wired sector holds data; Determining a second valid data block in the data block, the second valid data block refers to a valid data block including a dirty sector; determining a target valid data block in the second valid data block, in the target valid data block Contains multiple pages, any of which contains dirty sectors.

The writing module 602 is configured to write data in the target valid data block to the solid state hard disk. On the basis of the foregoing embodiment, the determining module 601 is configured to: traverse all sectors in the preset designated area in the buffer; and obtain a maximum continuous valid data block as the first valid data block, where the first The valid data block includes the most consecutive valid sectors. .

It should be noted that the dirty sector includes data to be written into the solid state hard disk, and the clean sector includes data that has been written into the solid state hard disk.

The foregoing modules are used to implement the foregoing method embodiments, and the implementation principles and technical effects are similar, and details are not described herein again.

FIG. 7 is a schematic structural diagram of Embodiment 1 of a storage device according to the present disclosure. The storage device 110 includes: a processor 701, a memory 702, a system bus (abbreviated as bus) 703, and a communication interface 704, a processor 701, a memory 702, and a communication interface. 704 are connected by system bus 703 and communicate with each other.

Processor 701 can be a central processing unit. The memory 702 is used to store instruction information. Communication interface 704 is used to communicate with external devices.

In a specific implementation process, the processor 701 runs the instruction information in the memory 702, and the method flow described in FIG. 1 can be performed.

Specifically, the processor 701 is configured to determine, in the cache, a first valid data block, where the first valid data block includes a plurality of consecutive valid sectors, and the wired sector stores data; Determining a second valid data block in the first valid data block, the second valid data block refers to a valid data block including a dirty sector; determining a target valid data block in the second valid data block, The target valid data block contains a plurality of pages, and any one of the pages contains a dirty sector. It is also used to write data in the target valid data block to the solid state hard disk.

On the basis of the foregoing embodiment, the processor 701 is specifically configured to: traverse all sectors of the preset designated area in the buffer; and obtain a maximum continuous valid data block as the first valid data block, where the first The valid data block includes the most consecutive valid sectors.

The dirty sector includes data to be written into the solid state hard disk, and the clean sector includes data that has been written into the solid state hard disk.

One of ordinary skill in the art will appreciate that all or a portion of the steps of implementing the various method embodiments described above can be accomplished by hardware associated with the program instructions. The aforementioned program can be stored in a computer readable storage medium. The program, when executed, performs the steps including the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

Finally, it should be noted that the above embodiments are only for explaining the technical solutions of the present invention, and are not intended to be limiting thereof; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that The technical solutions described in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and the modifications or substitutions do not deviate from the technical solutions of the embodiments of the present invention. range.

Claims

claims

1. A method of writing data. The method is applied to a storage device. The storage device includes a controller and a solid-state drive. The controller includes a cache. The cache includes multiple pages. Each page Each page includes multiple sectors, characterized in that the method includes:

Determine a first valid data block in the cache, the first valid data block includes a plurality of consecutive valid sectors, and the valid sectors store data;

Determine a second valid data block in the first valid data block, where the second valid data block refers to a valid data block including dirty sectors;

Determine a target valid data block in the second valid data block, where the target valid data block contains multiple pages, any one of which contains dirty sectors;

Write the data in the target valid data block to the solid state drive.

2. The method of claim 1, wherein determining the first valid data block in the cache includes:

Traverse all sectors of the preset designated area in the cache;

The largest continuous valid data block is obtained as the first valid data block, and the first valid data block includes the most continuous valid sectors.

3. The method according to claim 2, wherein the dirty sectors include data to be written to the solid state drive, and the clean sectors include data that have been written to the solid state drive.

4. A device for writing data. The device is used in a storage device. The storage device includes a controller and a solid-state drive. The controller includes a cache. The cache includes a plurality of pages. Each page A page includes multiple sectors, which are characterized by:

Determining module, used to determine a first valid data block in the above-mentioned cache memory, the first valid data block includes a plurality of continuous valid sectors, the wired sectors store data; in the first valid data Determine the first valid data block in the block, the first valid data block refers to the valid data block containing dirty sectors; determine the target valid data block in the second valid data block, the target valid data block Contains multiple pages, any one of which contains dirty sectors;

A writing module, configured to write the data in the target valid data block to the solid state disk.

5. The device according to claim 4, characterized in that the determining module is specifically used to Traverse all sectors in the preset designated area in the notification buffer; obtain the largest continuous valid data block as the first valid data block, and the first valid data block includes the most continuous valid sectors.

6. The device according to claim 5, wherein the dirty sectors include data to be written to the solid state drive, and the clean sectors include data that have been written to the solid state drive.