CN110837345A - Bad block table storage method and device - Google Patents

Abstract

The invention discloses a storage method and a storage device for a bad block table, and belongs to the technical field of data storage. In the storage method of the bad block table provided by the present invention, for the same group of flash memory, there is a global bad block table for storing all flash memory information in the group, and for each flash memory, there is a block management table for storing each block information in the flash memory. For the same group of flash memory controlled by the same SSD controller in the same SSD disk, in addition to having a global bad block table, for each flash memory, there is also a block management table that stores the information of each block in the flash memory, so that each flash memory has a block management table. There is at least one good block for storing each block information in its own flash memory, so as to improve the reliable management of the flash memory.

Description

Method and device for storing bad block table

technical field

The present invention relates to the technical field of data storage, and in particular, to a method and device for managing a bad block table.

Background technique

Memory is widely used in electronic products, so bad block management of memory is very important. Taking NAND Flash (flash memory) as an example, when users use flash memory, they should first scan all flash memory cards according to the flash memory documentation, remove bad blocks, and create a BBT (Bad Block Table).

The establishment and preservation of BBT is extremely important. If the BBT is not established and preserved, the bad blocks cannot be removed, which will cause some data to be stored on the bad blocks, resulting in the use of SSD (Solid State Disk, solid-state drive). Abnormal data loss reduces the reliability of the SSD. In an SSD disk, the SSD controller controls N different NAND Flashes. In this case, the traditional storage method of NAND Flash BBT, as shown in Figure 1, is to store the BBT that records all NAND Flash bad block information uniformly in a certain storage block of a certain NAND Flash.

Once the only NAND Flash that records all bad block information is damaged or physically destroyed, the bad block information of other available NAND Flash will be lost, which will make the entire SSD unusable and all NAND Flash will be scrapped.

SUMMARY OF THE INVENTION

In order to solve the above problems, the present invention provides a method and device for storing a bad block table.

In a first aspect, the present invention provides a method for storing a bad block table. For the same group of flash memory, there is a global bad block table for storing all flash memory information in the group, and for each flash memory, there is a block for storing the information of each block in the flash memory. Management table, the storage method includes:

When a bad block or an erase operation is generated, the global bad block table is updated, and the block management table of the flash memory corresponding to the bad block or the erase operation is updated.

The above-mentioned storage method, when generating a bad block or erasing operation, update the global bad block table, and update the block management table of the flash memory corresponding to the bad block or the erasing operation, including:

When a bad block is generated, the global bad block table is updated, and the bad block information table in the block management table of the flash memory to which the bad block belongs is updated according to the flash memory location to which the bad block belongs;

When an erase operation is generated, the usable block information table in the block management table of the flash memory to which the erased block belongs is updated according to the location of the flash memory to which the erased block belongs.

The above storage method, comprising: before generating a bad block or erasing operation, further comprising initializing the flash memory;

The initializing the same group of flash memory includes:

In the same group of flash memory, determine the good blocks and/or bad blocks in all blocks in each flash memory, and generate local good block information and/or local bad block information;

storing the local good block information and/or the local bad block information into the block management table of the respective flash memory;

Based on all the local bad block information in the flash memory in the same group, a global bad block table is obtained.

The above-mentioned storage method, described in the same group of flash memory, determines the good blocks and/or bad blocks in all blocks in each flash memory, and generates local good block information and/or local bad block information, including:

In the same group of flash memory, each block in the flash memory is judged as a usable block or a bad block according to the position sequence;

Local good block information and/or local bad block information are generated according to the positions of the usable blocks and/or bad blocks.

In the above storage method, the block management table includes a usable block information table and a bad block information table, the usable block information table is used to store local good block information, and the bad block information table is used to store local bad blocks information.

In the above storage method, the global bad block table is stored in any at least one flash memory in the same group of flash memory.

Above-mentioned storage method, described storage method also comprises:

When replacing or adding a flash memory, it is detected whether the replaced or newly added flash memory has a block management table, if not, a block management table is constructed, and the block management table of the replaced flash memory card is initialized.

The above storage method, after replacing or adding a flash memory, further includes:

The global bad block table is updated according to the block management table of the replaced or newly added flash memory card.

In the above storage method, both the global bad block table and the block management table are stored on good blocks.

In a second aspect, the present invention provides a storage device for a bad block table. For a flash memory in the same group, there is a global bad block table for storing all flash memory information in the group, and for each flash memory, there is a storage device for storing information about each block in the flash memory. A block management table, the storage device includes:

The updating module is used for updating the global bad block table when a bad block or erasing operation is generated, and updating the block management table of the flash memory corresponding to the bad block or the erasing operation.

In the storage method of the bad block table provided by the present invention, for the same group of flash memory, there is a global bad block table for storing all flash memory information in the group, and for each flash memory, there is a block management table for storing each block information in the flash memory. For the same group of flash memory controlled by the same SSD controller in the same SSD disk, in addition to having a global bad block table, for each flash memory, there is also a block management table that stores the information of each block in the flash memory, so that each flash memory has a block management table. There is at least one good block for storing each block information in its own flash memory, so as to improve the reliable management of the flash memory.

Description of drawings

The accompanying drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 shows that all the flash memory bad block information recorded in the prior art is stored in the memory block of the flash memory;

FIG. 2 is a schematic structural diagram of a flash memory chip;

FIG. 3 is a schematic diagram of storing a bad block table in an SSD disk according to an exemplary embodiment of the present invention;

4 is a flow chart of updating a block management table in an exemplary embodiment of the present invention;

FIG. 5 is a flowchart of flash memory initialization in an exemplary embodiment of the present invention;

FIG. 6 is a flowchart of updating the global bad block table after replacing or adding a flash memory in an exemplary embodiment of the present invention.

Detailed ways

In this article, NAND Flash refers to physical NAND Flash, which is a NAND Flash chip. NANDFlash structure is divided into five levels: chip (chip), wafer (die), grouping (plane), block (block), page (page). For example, Figure 2 shows the structure of a flash memory chip of Micron. Therefore, each NAND Flash is composed of multiple storage blocks (blocks in this text refer to storage blocks), and each storage block is divided into many storage pages, and a page is the basic unit of read and write operations. Among them, the block is the basic/minimum unit of the erase operation of NAND Flash.

Usually, when users use flash memory, they should first scan all flash memory cards according to the flash memory document, remove bad blocks, and establish a bad block table, namely BBT (Bad Block Table).

As shown in Figure 2, the BBT that records all NAND Flash bad block information is uniformly stored in a certain storage block of a certain NAND Flash. Once the only NAND Flash that records all bad block information is damaged or physically destroyed, the bad block information of other available NAND Flash will be lost, which will make the entire SSD unusable and all NAND Flash will be scrapped.

To solve the above problem, embodiments of the present invention provide a storage method and storage device for a bad block table.

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the storage method of the bad block table provided by the embodiment of the present invention, for the same group of flash memory, there is a global bad block table for storing all flash memory information in the group, and for each flash memory, there is a block management table for storing the information of each block in the flash memory. . For the same group of flash memory controlled by the same SSD controller in the same SSD disk, in addition to having a global bad block table, for each flash memory, there is also a block management table that stores the information of each block in the flash memory, so that each flash memory has a block management table. There is at least one good block for storing each block information in its own flash memory, so as to improve the reliable management of the flash memory.

Specifically, referring to FIG. 3 , the SSD disk has a global BBT, which is stored in flash memory 0, flash memory 0 also has a block management table for storing flash memory 0, and flash memory 1 has a block for storing flash memory 1. The block management table , the flash memory 2 has a block management table for storing the blocks of the flash memory 2 . In practical applications, the number of flash memory in the SSD is not limited to four in FIG. 3 , and may be one, two, three, five, etc., which is not specifically limited in the embodiment of the present invention.

The storage method of the bad block table according to the embodiment of the present invention includes S04: when a bad block or an erase operation is generated, the global bad block table is updated, and the block management table of the flash memory corresponding to the bad block or the erase operation is updated.

Associate the global bad block table with the block management table of each flash memory, so that when a bad block or erase operation is generated, not only the global bad block table is updated, but also the block management table of the flash memory corresponding to the bad block or the erase operation is updated, Further, the reliability of the use of the flash memory is improved, and when the bad block table information needs to be read, the bad block table information in the same group of flash memory can still be obtained from the global bad block table.

S041 and S042 are included in S04. (See Figure 4)

S042: When a bad block is generated, update the global bad block table, and update the bad block information table in the block management table of the flash memory to which the bad block belongs according to the flash memory location to which the bad block belongs. Specifically, when a bad block is generated, the global bad block table is updated to query which flash memory the current bad block exists in, and then the bad block information table in the block management table of the flash memory is updated. The bad block information table is used to store local bad block information in the flash memory. After the bad block information table is updated, the data in the flash memory block management table is updated, including the total number and location of bad blocks in the flash memory.

S044: When the erase operation is generated, update the available block information table in the block management table of the flash memory to which the erased block belongs according to the location of the flash memory to which the erased block belongs. Specifically, when an erase operation occurs, in which flash memory the current erase block exists is inquired, and then the good block information table in the block management table of the flash memory is updated. The good block information table is used to store local good block information in the flash memory. After the block information table is updated, the data in the flash memory block management table is updated, including the total number and location of good blocks in the flash memory.

The storage method of the bad block table according to the embodiment of the present invention includes S02 before S04: initialize the flash memory.

Specifically, S02 includes: S022, S024 and S026.

S022: In the same group of flash memory, determine the good blocks and/or bad blocks in all the blocks in each flash memory, and generate local good block information and/or local bad block information. Specifically, the same group of flash memory refers to the flash memory located in the same SSD disk and controlled by the same SSD controller. In the same group of flash memory, each block in the flash memory can be judged as a usable block or a bad block in sequence according to its position, and local good block information and/or local bad block information can be generated according to the position of the usable block and/or bad block. Of course, as a variant, in the same group of flash memory, each block in the flash memory can be judged as a usable block or a bad block, not according to the position sequence, but according to the service life of the flash memory, the use time, or the storage content, or the preset priority. The level and so on in turn determine each block in the flash memory as a usable block or a bad block. In addition to generating local good block information and/or local bad block information according to the positions of usable blocks and/or bad blocks, local good block information and/or local bad block information can also be generated according to the number of usable blocks and/or bad blocks, their respective proportions, etc. / or local bad block information.

S024: Store the local good block information and/or the local bad block information into the block management table of the respective flash memory. Each flash memory has its own corresponding block management table, and the block management table stores the information of the blocks in each flash memory. It should be noted that the local good block information and local bad block information in this application are local relative to the global, the local corresponds to each flash memory, and the global corresponds to a group of SSD disks, that is, all flash memories in the same group.

S026: Obtain a global bad block table based on all the local bad block information in the flash memory in the same group. Specifically, the global bad block table is obtained based on all the local bad block information of the flash memory in the group.

Among them, the global bad block table can be stored in any flash memory on the same group of flash memory, or any two different flash memory, or any three different flash memory, etc., so as to avoid the need to rebuild the global bad block after a certain flash memory is damaged table to improve the reliability of the global bad block table.

Of course, in this embodiment of the present invention, both the global bad block table and the block management table should be stored on good blocks.

In practical applications, a certain flash memory may be damaged or its service life expires and needs to be replaced. Therefore, the storage method of the bad block table of the present application also includes S06: when replacing or adding a flash memory, detect the replaced or newly added flash memory. Whether the flash memory has a block management table, if not, construct the block management table, and initialize the block management table of the replaced flash memory card. Specifically, to initialize the block management table of the replaced or newly added flash memory card, refer to the initialization of the flash memory in S02.

After S06, the method further includes: updating the global bad block table according to the block management table of the replaced or newly added flash memory card. The block management table of the flash memory to be replaced is associated with the global bad block table, which facilitates subsequent reading or management of the flash memory in the group (flash memory in the same SSD disk).

Figure 5 shows a flow of flash memory initialization. Specifically, it includes: judging whether each block information in the current flash memory is a bad block; if it is a bad block, generate the bad block information, and store it in the bad block information table of the block management table; if it is a good block, generate the good block initialization information, Store the available block information table; store the generated block management table in one or several available blocks of the current flash memory; determine whether all the flash memory of the current SSD disk has been searched; if not, select the unsearched flash memory to continue searching ; After the above is completed, a complete BBT (global bad block table) is obtained and stored in any flash memory.

FIG. 6 shows a flow of updating the global bad block table after replacing or adding a flash memory. Specifically, it includes: replacing or adding flash memory; detecting whether the updated or newly added flash memory has a block management table, if so, update the global bad block table, if not, initialize the updated or newly added flash memory to obtain the block management table and then update it Global bad block table. In this way, the update of the global bad block table after the flash memory is replaced is completed. After that, the SSD can be completely erased for normal use.

Another exemplary embodiment of the present invention provides a storage device for a bad block table. For a flash memory in the same group, there is a global bad block table for storing all flash memory information in the group, and for each flash memory, there is a storage device for storing each block in the flash memory. A block management table of information, the apparatus includes:

The updating module is used for updating the global bad block table when a bad block or erasing operation is generated, and updating the block management table of the flash memory corresponding to the bad block or the erasing operation.

In the described storage device, the update module includes:

A bad block update submodule is used to update the global bad block table when a bad block is generated, and update the bad block information table in the block management table of the flash memory to which the bad block belongs according to the flash memory location to which the bad block belongs;

The erasing operation updating sub-module is configured to update the usable block information table in the block management table of the flashing memory to which the erased block belongs according to the location of the flash memory to which the erased block belongs when the erasing operation is generated.

The storage device further includes an initialization module for initializing the flash memory.

Initialize modules, including:

The local information generation sub-module is used to determine the good blocks and/or bad blocks in all the blocks in each flash memory in the same group of flash memory, and generate local good block information and/or local bad block information;

The local information is stored in the submodule, for storing the local good block information and/or the local bad block information in the block management table of the respective flash memory;

The global information submodule is configured to obtain a global bad block table based on all local bad block information in the flash memory in the same group.

The local information generation submodule includes:

The judgment sub-module is used to judge each block in the flash memory as a usable block or a bad block according to the position sequence in the same group of flash memory;

A generating sub-module is configured to generate local good block information and/or local bad block information according to the positions of the usable blocks and/or bad blocks.

In the storage device, the block management table includes a usable block information table and a bad block information table, the usable block information table is used to store local good block information, and the bad block information table is used to store local bad block information. block information.

In the storage device, the global bad block table is stored in any at least one flash memory in the same group of flash memory.

In the storage device, it also includes:

A flash memory replacement or addition module is used to detect whether the replaced or newly added flash memory has a block management table when replacing or adding a flash memory, and if not, constructing a block management table and initializing the replaced flash memory card. Block management table.

In the storage device, it also includes:

A global replacement or addition module, configured to update the global bad block table according to the block management table of the replaced or newly added flash memory card.

In the storage device, both the global bad block table and the block management table are stored on good blocks.

The storage device for the bad block table according to the embodiment of the present invention can also perform the method performed by the storage device for the bad block table in FIG. 4 , FIG. 5 and FIG. The functions of the illustrated embodiment are not repeated here.

Preferably, an embodiment of the present invention further provides a data management device, including a processor, a memory, a computer program stored in the memory and running on the processor, and the computer program implements the above-mentioned bad blocks when executed by the processor Each process of the embodiment of the method for storing the table can achieve the same technical effect, and to avoid repetition, it will not be repeated here.

Embodiments of the present invention further provide a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, each process of the above embodiment of the method for storing the bad block table is implemented, and can achieve The same technical effect, in order to avoid repetition, will not be repeated here. The computer-readable storage medium is, for example, a read-only memory (Read-Only Memory, ROM for short), a random access memory (Random Access Memory, RAM for short), a magnetic disk, or an optical disk.

It should be noted that, herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, It also includes other elements not expressly listed or inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

From the description of the above embodiments, those skilled in the art can clearly understand that the method of the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is better implementation. Based on this understanding, the technical solutions of the present invention can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products are stored in a storage medium (such as ROM/RAM, magnetic disk, CD), including several instructions to make a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) execute the methods described in the various embodiments of the present invention.

The above specific examples further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principle of the invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (10)

1. A storage method of a bad block table is characterized in that a global bad block table for storing all flash memory information in a group is provided for flash memories in the same group, and a block management table for storing each block information in the flash memories is provided for each flash memory, and the storage method comprises the following steps:

and when a bad block or an erasing operation is generated, updating the global bad block table and updating a block management table of the flash memory corresponding to the bad block or the erasing operation.

2. The storage method according to claim 1, wherein the updating the global bad block table and the updating the block management table of the flash memory corresponding to the bad block or the erase operation when the bad block or the erase operation occurs comprise:

when a bad block is generated, updating a global bad block table, and updating a bad block information table in a block management table of a flash memory to which the bad block belongs according to the flash memory position to which the bad block belongs;

when an erasing operation is generated, according to the position of the flash memory to which the erased block belongs, the usable block information table in the block management table of the flash memory to which the erased block belongs is updated.

3. The method of claim 1, comprising: before the generating of the bad block or the erasing operation, initializing the flash memory;

the initializing the same group of flash memories includes:

in the same group of flash memories, judging good blocks and/or bad blocks in all blocks in each flash memory to generate local good block information and/or local bad block information;

storing the local good block information and/or the local bad block information into a block management table of each flash memory;

and obtaining a global bad block table based on all the local bad block information in the flash memories in the same group.

4. The storage method according to claim 3, wherein the generating local good block information and/or local bad block information of the judged good blocks and/or bad blocks in all blocks in each flash memory in the same group of flash memories comprises:

in the same group of flash memories, sequentially judging each block in the flash memories as a usable block or a bad block according to the position sequence;

and generating local good block information and/or local bad block information according to the positions of the usable blocks and/or the bad blocks.

5. The deposit method according to claim 1, wherein a usable block information table for storing local good block information and a bad block information table for storing local bad block information are included in the block management table.

6. The method of claim 1, wherein the global bad block table is stored in any at least one of the flash memories in the same set of flash memories.

7. The method of storing according to claim 1, further comprising:

when the flash memory is replaced or newly added, whether the replaced or newly added flash memory has a block management table is detected, if not, the block management table is constructed, and the block management table of the replaced flash memory card is initialized.

8. The storage method according to claim 7, further comprising, after replacing or adding the flash memory:

and updating the global bad block table according to the block management table of the replaced or newly added flash memory card.

9. A deposit method according to claim 1, wherein said global bad block table and said block management table are both stored on a good block.

10. A storage device of a bad block table, which is characterized in that, for the same group of flash memories, a global bad block table for storing all flash memory information in the group is provided, and for each flash memory, a block management table for storing each block information in the flash memory is provided, the storage device comprises:

and the updating module is used for updating the global bad block table and updating the block management table of the flash memory corresponding to the bad block or the erasing operation when the bad block or the erasing operation is generated.

Images