KR101247388B1 - Method and apparatus for processing trim command in hybrid-mapping flash translation layer - Google Patents

Abstract

A method and apparatus are provided for processing TRIM instructions using hybrid-mapping FTL. The trim command requests the deletion of a specific sector, and the FTL stores the sector requested for deletion as data in or outside the FTL. The FTL deletes the stored sectors when a function such as merge, garbage collection, or cleaning is performed.

Description

METHOD AND APPARATUS FOR PROCESSING TRIM COMMAND IN HYBRID-MAPPING FLASH TRANSLATION LAYER}

The following embodiments relate to a flash memory based storage method and apparatus using a hybrid-mapped FTL, and more particularly, to a method and apparatus for processing a TRIM instruction using a hybrid-mapped FTL.

Flash memory is a memory semiconductor having nonvolatile characteristics. Solid State Disk (SSD), which is based on flash memory, has faster input-output (I / O) speed, noise, low power, and impact compared to conventional hard disk (HDD). It has advantages such as durability.

The flash memory cannot directly write other information on a device in which information is already recorded due to the characteristics of a non-volatile device. That is, the SSD using the flash memory cannot overwrite the changed information on the device in which the information is recorded after writing the information in a specific flash memory device. Therefore, the flash memory must first delete the information written in the device, and then write again.

In addition to the above-described non-overwrite characteristic, the flash memory has characteristics such as read / write in units of pages, deletion in units of blocks, and limitation on the number of deletions. Because of the characteristics of other flash memories different from these conventional HDDs, the flash memory cannot use the conventional file system as it is.

The Flash Translation Layer (FTL) hides the inherent characteristics of flash memory and emulates the interface of a typical HDD, so that existing file systems use devices such as SSDs. Make it available.

Storage devices constructed using flash memory can be improved in performance by minimizing deletion. Thus, the FTL needs to include a function to minimize deletion.

There are various FTLs such as Page-Mapping, Block-Mapping, and Superblock, but none of them can completely eliminate deletion. This is because the file system of the host using the flash memory storage device overwrites the file system.

If the file system avoids overwriting requests, the performance of flash memory storage can be improved. However, since storage capacity is limited, deletion is inevitable. In addition, the storage device may not know whether the requested record is a record for avoiding overwriting. Therefore, the storage device cannot delete unnecessary data.

In addition, if data is distributed and recorded without considering the characteristics of the storage device, the remaining space of the storage device may be quickly consumed, and adversely affect the performance of the storage device such as I / O and wear.

If the file system provides the storage device with information about sectors that need to be deleted, the storage device can use this information to drive performance improvements by deleting unnecessary sectors in a timely manner.

The TRIM command is a data-set management command defined in the ATA-8 standard, and provides information on a sector to be deleted between a file system and a storage device.

Flash memory is typically 10 times slower than writes. Therefore, it is not efficient for a storage device using an FTL such as hybrid mapping, page-mapping, block-mapping, or superblock to immediately remove a sector requested to be erased by a trim command.

The trim command may also request sectors across the storage device as sectors that need to be erased. In such a case, if the FTL deletes all requested sectors immediately, serious problems may occur in the performance of the storage device.

According to an aspect of the present invention, receiving identification information indicating a plurality of first blocks, adding the plurality of first blocks as a block to be deleted to the deletion block list based on the identification information and the deletion block list A method of controlling a flash memory is provided, the method comprising deleting a plurality of second blocks which are represented.

The method may further include receiving a write command for a third block and retrieving the deleted block list to exclude the third block of the plurality of second blocks represented by the deleted block list. Can be.

According to another aspect of the invention, a receiving unit for receiving identification information representing a plurality of first blocks. A storage unit storing a deletion block list and the plurality of second blocks added to the deletion block list as a block to be deleted and stored in the storage unit based on the identification information; Provided is a flash memory translation layer device comprising a control unit for deleting blocks.

The receiver may receive a write command for a third block, and the controller may exclude the third block among the plurality of second blocks indicated by the deletion block list.

According to another aspect of the invention, receiving a trim command including the sequence number of the first sector of the plurality of first sectors and the number of the plurality of first sectors, based on the trim command in the trim sector list A method of processing a trim command of a solid state disk is provided, comprising adding the plurality of first sectors as sectors to be deleted and deleting the plurality of second sectors indicated by the trim sector list.

According to still another aspect of the present invention, an interface unit for transmitting and receiving an input / output signal, a flash memory unit for storing data and providing writing and reading of the data, and an FTL unit for controlling the flash memory unit based on the input / output signal, The interface unit receives a trim command including a sequence number of a first sector among a plurality of first sectors and a number of the plurality of first sectors, and the FTL unit generates the plurality of first sectors based on the trim command. In addition to a trim sector list indicating sectors to be deleted, a solid state disk is provided which deletes a plurality of second sectors represented by the trim sector list in the flash memory section.

The interface unit may receive a write command for a third sector, and the FTL unit may search the trim sector list to exclude the third sector of the plurality of second sectors indicated by the trim sector list. .

The trim sector list may include a plurality of primary indices, each primary index being a sequence within a partial range allocated to the primary index among the plurality of second sectors represented by the trim sector list. It can store information that can represent the sectors having.

The partial ranges allocated to each of the plurality of primary indexes may have the same size.

Each primary index may include a plurality of secondary indexes.

The FTL unit searches for a first index corresponding to a partial range including a sequence number of the first sector among the plurality of primary indexes, and includes the sequence number of the first sector and the data structure indicated by the first index. By adding the information corresponding to the number of the plurality of first sectors, the plurality of sectors indicated by the trim command may be added to the trim sector list as sectors to be deleted.

The data structure may be a linked list.

If the partial range of the first index does not include all of the plurality of sectors, the FTL unit divides a continuous part including a last sector among the plurality of first sectors into a plurality of second sectors, and The trim command indicated in the trim sector list by adding the sequence number of the first sector of the plurality of second sectors and the number of the plurality of second sectors to a data structure indicated by a second index that is a next index of the first index. A plurality of sectors may be added as sectors to be deleted, and the first sector of the plurality of second sectors may be a sector having the smallest sequence number included in the partial range of the second index.

The FTL unit may manage the flash memory unit by dividing the block into a log block and a data block, and the FTL unit records a sector requested to be recorded in a log block and a sector that is not represented by the trim sector list among the sectors recorded in the log block. By copying only the data blocks, the plurality of second sectors indicated by the trim sector list can be deleted.

A method and apparatus are provided for storing information indicative of a block requested to be deleted as data within or outside the FTL, and subsequently deleting the blocks.

A method and apparatus are provided for storing information indicative of sectors requested to be erased by a trim command as data within or outside the FTL, and subsequently deleting the sectors.

Methods and apparatus are provided for deleting blocks or sectors when a function such as merging, garbage collection, or cleaning is performed using hybrid-mapping FTL.

The above methods and apparatus allow the storage device to process the trim commands delivered by the host's file system. File systems can use trim commands to distribute I / O, and storage can reduce the occurrence of erase. Thus, the I / O performance of the storage device can be improved and the wear of the flash memory used by the storage device can be improved.

1 illustrates a configuration of an SSD according to an embodiment of the present invention.
2 illustrates a structure of a trim command according to an embodiment of the present invention.
3 illustrates a data structure of a trim sector list according to an example of the present invention.
4 illustrates a merge according to an example of the present invention.
5 illustrates a structure of an FTL unit according to an embodiment of the present invention.
6 illustrates a flash memory control method according to an embodiment of the present invention.
7 illustrates a trim command processing method of an SSD according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to or limited by the embodiments. Like reference symbols in the drawings denote like elements.

1 illustrates a configuration of an SSD according to an embodiment of the present invention.

The SSD 100 includes an interface unit 110, an FTL unit 120, and a flash memory unit 130. The SSD 110 may further include a DRAM unit 140.

The interface unit 110 performs an interface function with the host 190 using the SSD 100. In general, the interface unit 110 is directly connected to a storage controller of the host 190. The interface unit 110 may provide an interface according to a specific specification such as SCSI, IDE, or SATA.

The interface unit 110 receives an input signal (eg, a control signal or input data) from the host 190, and transmits an output signal (eg, a control signal or output data) to the host 190. The input signal and the output signal may be signals according to a specific specification such as an ATA command.

In addition, the interface unit 110 may request a command of the specific specification (eg, ATA standard) received from the host 190 (eg, a read, write, or trim command) that the FTL unit 120 requires. ) Into the form

The FTL unit 120 controls the flash memory unit 130. The FTL unit 120 may be a module that provides a function of the FTL. The FTL unit 120 reads data from the flash memory unit 130 or writes data to the flash memory unit 130 based on input / output signals transmitted and received by the interface unit 110.

The structure of the FTL unit 120 according to an embodiment of the present invention will be described in detail with reference to FIG. 5 below.

The flash memory unit 130 stores data and provides reading and writing of the data under the control of the FTL unit 120.

The flash memory unit 130 reads and writes data in units of blocks. The FTL unit 120 requests reading and writing of data in units of blocks. If the size of the input / output unit (eg, sector) used by the file system of the host 190 is different from the size of the block (generally, the size of the sector is an integer multiple of the size of the block). ) May access data of the flash memory unit 130 in units of sectors.

The flash memory unit 130 may include a NAND controller 132 for directly controlling an internal flash memory chip.

The flash memory unit 130 may include a plurality of planes 134. Each plane includes one or more flash memory chips. The plurality of planes may operate independently of each other or in pairs.

The DRAM (Dynamic Random Access Memory) unit 140 is connected to the FTL unit 120 to store volatile data. The DRAM unit 140 may be a component included in the FTL unit 120.

The SSD 100 may include a plurality of flash memory units 130. Each flash memory unit 130 may be connected to an independent bus and operate in parallel.

A trim command processing of the SSD 100 will be described below.

The interface unit 110 receives an input signal indicating a trim command from the host 190. The interface unit 110 transmits the received trim command to the FTL unit 120.

The trim command includes identification information indicating a plurality of sectors to be deleted. An example of the structure of a trim command is described in detail with reference to FIG. 2 below.

The FTL unit 120 adds a plurality of sectors to be deleted to the trim sector list based on the trim command.

The trim sector list is a data structure managed by the FTL unit 120 and stores a list of sectors to be deleted transmitted through a trim command. The trim sector list may be stored in the DRAM unit 140.

An example of a trim sector list is described in detail with reference to FIG. 3 below.

Sectors represented by the trim sector list (ie, sectors added to the trim sector list by one or more trim commands) are actually deleted from the flash memory unit 130 by a specific operation performed by the FTL unit 120.

The specific task may be periodic merging, garbage collection, or cleaning. Merging according to an example of the present invention is described in detail with reference to FIG. 4 below.

The host 190 may request recording for sectors already included in the trim sector list. In this case, the sector requested to be written should not be deleted from the flash memory unit 130 afterwards.

Therefore, when the interface unit 110 receives a recording request for a specific sector and transmits the recording request to the FTL unit 120, the FTL unit 120 searches for a trim sector list, and the sector indicated by the trim sector list. Among them, it is determined whether the sector requested for recording is included.

If the sector requested to be recorded is included in the sector indicated by the trim sector list, the FTL unit 120 excludes the sector requested to be recorded from the sector indicated by the trim sector list.

2 illustrates a structure of a trim command according to an embodiment of the present invention.

The trim command 200 includes identification information 210 representing a plurality of sectors. The identification information 210 is information for identifying which sectors are sectors to be deleted.

The identification information 210 may include a number 220 of a first sector of a plurality of sectors to be deleted and a number 230 (or length) of the plurality of sectors.

The maximum value of the number 230 may be limited according to the specification of the trim command or the interface specification with the host 190.

One trim command may include a plurality of identification information 210.

3 illustrates a data structure of a trim sector list according to an example of the present invention.

In general, while the FTL unit 120 processes the trim command, the host 190 stops waiting for the result of the trim command. Accordingly, the FTL unit 120 should use a data structure that is easy to manage the trim sector list (eg, insert, delete, and retrieve sectors).

In this example, the trim sector list includes a plurality of indices 310.

Sectors provided by the SSD 100 for input and output of data have a number (Number) of a certain range (for example, 0 to 2047). The entire range of sequences may be divided into a plurality of sub ranges.

Each index 310 is assigned one subrange of the plurality of subranges. In FIG. 3, partial ranges of (0 to 511), (512 to 1023), (1024 to 1535), and (1536 to 2047) are allocated to the first index, the second index, the third index, and the fourth index, respectively. .

The plurality of partial ranges may all be the same size. In other words, each index may cover sectors of the same subrange.

Each index stores information that can indicate sectors with a sequence number within the subrange assigned to them among the sectors to be deleted indicated by the trim sector list.

When the sequence number 200 and the number 230 of sectors to be deleted transmitted by the trim command 200 are transmitted to the FTL unit 120, the FTL unit 120 indexes the range corresponding to the partial range to which the sectors to be deleted belong. Stores information that can indicate the sectors to be deleted. For example, the FTL unit 120 adds information corresponding to the sequence number 200 of the first sector and the number 230 of sectors to be deleted, to the data structure indicated by the index.

The information that may indicate the sectors to be deleted may be node 320 of the linked list. In this case, the index 310 may be a link (or pointer) pointing to the first node 320. The linked list 330 may include a sequence number 330 of a first sector of the plurality of series and a number 340 (or length) of the plurality of series. Node 320 may also include a link 350 that points to the next node 320.

If the entire range of sectors is large, each index may include a plurality of secondary indices. In this case, the partial range assigned to the index is repartitioned and assigned to each of the secondary indexes. It is also possible for an index to have a hierarchical structure of more than two orders.

Hereinafter, an example in which the FTL unit 120 manipulates a trim sector list according to a trim command will be described.

Insertion of sectors to be deleted

When the interface unit 110 receives a trim command in which the number 220 is 0 and the number 230 is 100, the FTL unit 120 includes sectors having a sequence number from 0 to 99 in the trim sector list.

The FTL unit 120 searches the index 310 corresponding to the partial range in which the sequence number 200 is included. The partial range of the retrieved first index is from 0 to 511. The sequence numbers 0 to 99 are all included in the partial range allocated to the first index.

Accordingly, the FTL unit 120 inserts the node 320 having the sequence number 330 of 0 and the number 340 of 100 into the first index.

Next, when the interface unit 110 receives a trim command in which the number 220 is 200 and the number 230 is 10, the FTL unit 120 includes sectors having a sequence number from 200 to 209 in the trim sector list. Let's do it.

All of the above sequence numbers are included in the partial range allocated to the first index.

Therefore, the FTL unit 120 inserts the node 320 having the sequence number 330 of 200 and the number 340 of 10 into the first index. The inserted node 320 may be connected by a link 350 of the tail node 320 at the end of the nodes 320 previously inserted into the first index. Alternatively, the inserted node 320 may point to the link 350 of the first head node 320 among the nodes 320 previously inserted into the first index. In this case, the first index changes its value to point to the newly inserted node 320.

If the range of the sector represented by the node 320 to be newly inserted is overlapped in whole or in part with the range of the sector represented by the node 320 previously inserted, or if the range of both is continuous with each other, the node to be newly inserted. 320 and the node 320 to be inserted previously may be merged. In this case, in general, both are merged by changing the sequence number 330 or the number 340 of the previously inserted node 320.

Insert sectors that span a subrange of two indices

If the sequence of sectors to be deleted spans partial ranges corresponding to two or more indices, the plurality of sectors to be deleted must be divided and added to each index.

That is, when the sequence number of sectors to be deleted is a part range of the n th index and the other part is a partial range of the n + 1 th index, the FTL unit 120 determines that all sectors to be deleted indicated by the trim command are included. Splitting a plurality of sectors corresponding to a partial range of the n + 1 th index from the indexes.

A portion corresponding to the partial range of the n-th index among all sectors is named first sectors, and the remaining portion corresponding to the partial range of the n + 1th index is named second sectors.

The sequence number 330 of the first sectors is the sequence number 330 of the original whole sectors.

The sequence number 330 of the second sectors is the smallest value of the partial range of the n + 1 th index. That is, the first sector of the second sectors is the sector with the smallest sequence number included in the partial range of the n + 1 th index.

The number 340 of the first sectors is the number of sectors included in the partial range of the nth index, and the number 340 of the second sectors is the number of sectors included in the partial range of the n + 1th index.

Further, the first sectors are sequential sectors including the first of the original whole sectors, and the second sectors are consecutive sectors including the last sector of the original whole sectors.

If the number of sectors to be erased is very large, the entire sectors may be divided into several parts. When the maximum value that the number 230 of the plurality of sectors 230 indicated by the identification information 210 of the trim command may have is k (where k may be a value determined by an interface specification such as ATA or a trim command specification), an index If the size of the partial range of is greater than or equal to k, the entire sectors are divided into only two parts at most.

For example, when the interface unit 110 receives a trim command in which the number 220 is 1000 and the number 230 is 100, the FTL unit 120 should include sectors having a sequence number from 1000 to 1099 in the trim sector list. do.

Some of the above sequence numbers (1000 to 1023, 24) are included in the partial range assigned to the second index, and the remaining portions (1024 to 1099, 76) are included in the partial range assigned to the third index. do.

Accordingly, the FTL unit 120 inserts the node 320 having the order number 330 of 1000 and the number 340 of 24 into the second index, and the order number 330 of 1024 and the number 340 of the third index. Inserts node 320 with " 76 "

Exclusion of certain sectors after insertion of sectors to be deleted

It is sometimes necessary to remove a particular sector from among the sectors indicated by the trim sector list. For example, when the interface unit 110 receives a write command for a specific sector and transmits the write command to the FTL unit 120, the FTL unit 120 should exclude the specific sector from the sector indicated by the trim sector list. .

In this case, the FTL unit 120 first searches whether a particular sector is included among the sectors indicated by the trim sector list.

First, the FTL unit 120 calculates an index 310 corresponding to a partial range to which the sequence number of the specific sector belongs.

The FTL unit 120 searches for information indicating sectors to be deleted in the data structure indicated by the index 310.

When the information is the node 320 of the linked list, the FTL unit 120 may search all the nodes 320 along the link 350, and the order number 330 and the number of each of the nodes 320 are different. Through 340, it may be determined whether the order of a particular sector is included among the sectors represented by the node 320.

When a particular sector among the sectors indicated by the trim sector list is included, the FTL unit 120 excludes the specific sector from the sectors indicated by the trim sector list.

When the FTL unit 120 finds a node to which the sequence number of the particular sector belongs, the FTL unit 120 divides the node into two nodes 320. The first node is a node representing sectors having a sequence number before the specific sector, and the second node is a node representing sectors having a sequence number after the specific sector.

If the specific sector is the first or the last of the sectors indicated by the searched node, the FTL unit 120 may exclude the particular sector by changing the value of the sequence number 320 or the length 340 of the searched node.

For example, when the node having the order number 330 is 1536 and the number 340 is 5 is stored in the linked list indicated by the fourth index, and the node with the order number 1538 is excluded, the FTL unit 120 determines the node. Is divided into two nodes, that is, a first node having a sequence number 330 of 1536, a number 340 of 2, and a second node having a sequence number of 330 of 1539 and a number 340 of 2, and a first node. And a second node.

4 illustrates a merge according to an example of the present invention.

The hybrid-mapping divides the blocks of the flash memory unit 130 into a log block 410 and a data block 420.

The log block 410 may be managed by page mapping, and the data block 420 may be managed by block mapping. Therefore, the hybrid mapping method may provide faster I / O performance than block mapping while using a small mapping table.

The FTL unit 120 that provides the hybrid mapping performs a recording in the log block 410 when a recording for the sector is requested. When all the log blocks 410 are written, the FTL unit 120 copies the contents of the log blocks 410 to the data block 420 through periodic merging.

When merging, the FTL unit 120 searches the trim sector list 300 to determine whether the sector represented by the log block 410 (ie, recorded in the log block) is included among the sectors indicated by the trim sector list 300. Check it. If the sector represented by the log block 410 is in the trim sector list 300, the sector is unnecessary and the FTL unit 120 excludes the sector from the merge (ie, copy).

That is, the FTL unit 120 may delete the plurality of sectors indicated by the trim sector list 300 by copying only the sectors not indicated by the trim sector list 300 among the sectors indicated by the log block 410 into the data block.

In addition, recording may be requested for sectors that are already in the trim sector list 300. In this case, if the sector requested to be recorded is left in the trim sector list 300, the sector is excluded at the time of merging even though the sector indicated by the log block 410 is deleted, and the contents of the recording are lost. Accordingly, the FTL unit 120 excludes the sector from the trim sector list 300 while writing to the log block 410.

The technical concept used in the aforementioned merging may be applied to a task of moving unnecessary data or data that is not deleted (eg, garbage collection or clear operation). That is, even when the garbage collection or clear operation is performed, the FTL unit 120 may determine whether to delete the sector with reference to the trim sector list 300.

5 illustrates a structure of an FTL unit according to an embodiment of the present invention.

FTL portion 120 may be a hybrid-mapped FTL portion that provides the hybrid-mapping described above.

The FTL unit 120 may include a receiver 510, a controller 520, and a storage 530.

The receiver 510 receives a command necessary for the operation of the flash memory storage device from the interface unit 110 or the like.

For example, the receiver 510 receives a trim command (also, identification information of a block included in the trim command) and a write command for the block.

The storage unit 530 stores data necessary for the operation of the FTL unit 120.

For example, the storage unit 530 may store a trim sector list indicating a list of blocks to be deleted, and store the index 310 and the node 320 in the trim sector list.

The storage unit 530 may be a DRAM unit 140. In addition, the storage unit 530 may mean an interface for controlling the DRAM unit 140. In this case, the actual data is stored in the DRAM unit 140.

The controller 520 performs a series of operations necessary for reading and writing data, and controls the flash memory unit 130.

For example, the controller 520 adds a plurality of blocks as a block to be deleted to the deletion block list based on the identification information of the trim command. The controller 520 stores the added deletion block list in the storage 530. In addition, the controller 520 deletes the blocks indicated by the deleted block list. In order to perform the delete operation, the controller 520 may perform the merge, garbage collection, or cleaning operation described above, and may perform an operation for changing the contents of the deletion block list.

Technical contents according to an embodiment of the present invention described above with reference to FIGS. 1 to 4 may be applied to the present embodiment as it is. Therefore, more detailed description will be omitted below.

In particular, the sector described with reference to FIGS. 1 to 4 may be a unit of input / output in the file system used by the host 190, whereas in the flash memory unit 130, a block may be a unit of input / output. Therefore, the technical idea of the sector in the above-described embodiment can be applied to the block in this embodiment. In addition, the technical concept of the trim sector list in the above-described actual example may be applied to the erased block list in the present embodiment.

6 illustrates a flash memory control method according to an embodiment of the present invention.

In operation S610, identification information (eg, a trim command) indicating the plurality of first blocks is received.

In operation S620, a plurality of first blocks is added as a block to be deleted to the deletion block list based on the received identification information.

In step S630, a write command for the second block is received.

In step S640, it is checked whether the second block is included in the deletion block list.

In operation S650, when the second block is included in the deleted block list, the second block among the plurality of third blocks represented by the deleted block list is excluded.

In operation S660, the plurality of third blocks indicated by the deletion block list is deleted.

Technical contents according to an embodiment of the present invention described above with reference to FIGS. 1 to 5 may be applied to the present embodiment as it is. Therefore, more detailed description will be omitted below.

7 illustrates a trim command processing method of an SSD according to an embodiment of the present invention.

In step S710, a trim command is received. The trim command includes the order of the first sector of the plurality of first sectors and the number of the plurality of first sectors.

In steps S720 to S750 to be described below, a plurality of first sectors are added as sectors to be deleted to the trim sector list based on the received trim command.

The trim sector list includes a plurality of primary indices. Each primary index includes information that may indicate sectors having a sequence number within a partial range allocated to the primary index among the plurality of second sectors indicated by the trim sector list.

In step S720, an index corresponding to a partial range including the order of the first sector of the first sectors among the first indexes is searched. The searched index is named the first index.

In step S730, it is checked whether the partial range of the first index includes all of the first sectors. If the partial range of the first index includes all of the first sectors, step S750 is executed after the following steps S740 to S742 are executed, otherwise step S750 is immediately executed.

In step S740, the continuous portion including the last sector of the first sectors is divided into a plurality of third sectors.

In step S742, the order of the first sector of the third sectors and the number of third sectors are added to the data structure indicated by the second index, which is the next index of the first index.

At this time, the first sector of the third sectors is the sector having the smallest sequence number included in the partial range of the second index.

The data structure can be a linked list.

In operation S750, information corresponding to the order of the first sector and the number of the first sectors of the first sectors is added to the data structure indicated by the first index.

In step S760, a write command for the fourth sector is received.

In step S770, it is checked whether the fourth sector is included in the trim sector list. If the fourth sector is included in the trim sector list, step S780 is executed.

In step S780, a fourth sector of the second sectors indicated by the trim sector list is excluded.

In steps S790 and S792 to be described later, the second sectors indicated by the trim sector list are deleted.

In step S790, the sector whose recording is requested is recorded in the log block.

In step S792, only sectors of the sectors recorded in the log block that are not represented by the trim sector list are copied to the data block.

Technical contents according to an embodiment of the present invention described above with reference to FIGS. 1 to 6 may be applied to the present embodiment as it is. Therefore, more detailed description will be omitted below.

Method according to an embodiment of the present invention is implemented in the form of program instructions that can be executed by various computer means may be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as a hard disk, a floppy disk and a magnetic tape, optical recording media such as CD-ROM and DVD, magnetic recording media such as a floppy disk Optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

100: SSD
120: FTL section
190: host

Claims (20)

delete delete delete delete Receiving a trim command including a sequence number of a first sector of a plurality of first sectors and a number of the plurality of first sectors;
Adding the plurality of first sectors as sectors to be deleted to a trim sector list based on the trim command; And
Deleting a plurality of second sectors indicated by the trim sector list.
Including,
The deleting of the plurality of second sectors indicated by the trim sector list may include:
Writing a sector requested for recording to a log block; And
Copying only the sectors recorded in the log block, which are not represented by the trim sector list, to the data block;
Including a trim command processing method of a solid state disk. The method of claim 5,
Receiving a write command for the third sector; And
Retrieving the trim sector list and excluding the third sector of the plurality of second sectors indicated by the trim sector list
The trim command processing method of the solid state disk further comprising. The method of claim 5,
The trim sector list includes a plurality of primary indices, each primary index having a sequence number within a partial range assigned to the primary index among the plurality of second sectors represented by the trim sector list. A method of processing a trim command for a solid state disk, comprising information that can indicate sectors. The method of claim 7, wherein
Adding the plurality of first sectors indicated by the trim command to the trim sector list as sectors to be deleted,
Retrieving a first index corresponding to a partial range including a sequence number of the first sector among the plurality of primary indexes; And
Adding information corresponding to the order of the first sector and the number of the plurality of first sectors to a data structure indicated by the first index;
Including a trim command processing method of a solid state disk. 9. The method of claim 8,
And said data structure is a linked list. 9. The method of claim 8,
Adding the plurality of first sectors indicated by the trim command to the trim sector list as sectors to be deleted,
When the partial range of the first index does not include all of the plurality of first sectors, dividing a continuous portion including a last one of the plurality of first sectors into a plurality of second sectors; And
Adding a sequence number of a first sector of the plurality of second sectors and a number of the plurality of second sectors to a data structure indicated by a second index that is a next index of the first index
Wherein the first sector of the plurality of second sectors is a sector having the smallest sequence number included in the partial range of the second index. delete An interface unit for transmitting and receiving an input / output signal;
A flash memory unit for storing data and providing writing and reading of the data; And
Flash Translation Layer (FTL) unit for controlling the flash memory unit based on the input / output signal
Including,
The interface unit receives a trim command including a sequence number of a first sector among a plurality of first sectors and a number of the plurality of first sectors,
The FTL unit adds the plurality of first sectors to a trim sector list indicating sectors to be deleted based on the trim command, and deletes a plurality of second sectors represented by the trim sector list in the flash memory unit. disk. The method of claim 12,
The interface unit receives a write command for a third sector,
And the FTL portion retrieves the trim sector list to exclude the third sector of the plurality of second sectors indicated by the trim sector list. The method of claim 12,
The trim sector list includes a plurality of primary indices, each primary index having a sequence number within a partial range assigned to the primary index among the plurality of second sectors represented by the trim sector list. A solid state disk, storing information that can represent sectors. 15. The method of claim 14,
And the partial ranges assigned to each of the plurality of primary indices have the same size. 15. The method of claim 14,
Each primary index comprises a plurality of secondary indices. 15. The method of claim 14,
The FTL unit searches for a first index corresponding to a partial range including a sequence number of the first sector among the plurality of primary indexes, and includes the sequence number of the first sector and the data structure indicated by the first index. And adding the plurality of sectors indicated by the trim command as sectors to be deleted to the trim sector list by adding information corresponding to the number of the plurality of first sectors. 18. The method of claim 17,
And the data structure is a linked list. 18. The method of claim 17,
When the partial range of the first index does not include all of the plurality of sectors, the FTL unit divides a continuous part including the last sector among the plurality of first sectors into a plurality of second sectors, The trim command indicates to the trim sector list by adding the sequence number of the first sector of the plurality of second sectors and the number of the plurality of second sectors to a data structure indicated by a second index that is a next index of the first index. Add the plurality of sectors as sectors to be deleted,
And a first sector of the plurality of second sectors is a sector having the smallest order number included in the partial range of the second index. The method of claim 12,
The FTL unit manages the flash memory unit by dividing it into log blocks and data blocks.
The FTL unit deletes a plurality of second sectors indicated by the trim sector list by recording a sector requested to be recorded in a log block, and copying only sectors not indicated by the trim sector list among the sectors recorded in the log block into the data block. That, solid state disk.

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