Flash Translation Layer

Overview

This repository contains the simple Flash Translation Layers made on the Linux Environments.

Furthermore, this repository not only works on the ramdisk but also works on various devices(e.g. Zoned Block Device, and bluedbm, etc.).

If you have any questions about this project, please contact the maintainer (ss5ki.nosp@m.jun@.nosp@m.gmail.nosp@m..com).

Build

These instructions based on the Ubuntu(>=16.04) environments

Prerequisite

Before you build this repository, you must install some packages from the package manager.

sudo apt update -y
sudo apt install -y git make gcc g++ libglib2.0-dev

After you download the packages you must receive this project code by using git clone like below.

git clone --recursive ${REPOSITORY_URL}

Now you move to this repository's project directory root by using mv.

If you want to use a module like Zoned Block Device module, you must set the value of the USE_ZONE_DEVICE variable to 1 in the Makefile.

Additionally, you must install a valid library for each module. Each module's requirements are as follows.

• zone: libzbd
• bluedbm: libmemio

Moreover, before you run the Zoned Block Device-based program, You must check that you give the super-user privileges to run the Zoned Block Device-based programs.

Test

If you want to generate test files, execute the below command.

make clean && make -j$(nproc) test

After the build finish, you can get the various test files from the results. Run those files to test the project's module works correctly.

Execution

If you want to generate a release program through the main.c, then you must execute the below commands.

make clean && make -j$(nproc)

Now, you can run that program by using ./a.out

How to use this project

You can easily use this program like below. This program writes the random data into 10 segments. And read from each segment written data. Also, do garbage collection after the number of write to the segments is the multiplication of 5.

#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>

#include "include/module.h"
#include "include/flash.h"
#include "include/page.h"
#include "include/log.h"
#include "include/device.h"

int main(void)
{
        struct flash_device *flash = NULL;
        char buffer[8192];
        assert(0 == module_init(PAGE_FTL_MODULE, &flash, RAMDISK_MODULE));
        pr_info("module initialize\n");
        flash->f_op->open(flash, NULL, O_CREAT | O_RDWR);
        for (int i = 0; i < 8192 * 10; i++) {
                int num;
                size_t sector;
                num = i * 2;
                memset(buffer, 0, 8192);
                *(int *)buffer = num;
                sector = rand() % (1 << 31);
                flash->f_op->write(flash, buffer, sizeof(int), sector);
                pr_info("write value: %d\n", *(int *)buffer);
                memset(buffer, 0, 8192);
                flash->f_op->read(flash, buffer, sizeof(int), sector);
                pr_info("read value: %d\n", *(int *)buffer);
                if (i % 8192 * 5 == 0) {
                        flash->f_op->ioctl(flash, PAGE_FTL_IOCTL_TRIM);
                }
        }
        flash->f_op->close(flash);
        assert(0 == module_exit(flash));
        pr_info("module deallcation\n");

        return 0;
}

How to get this project's documents

You can get this program's documentation file by using doxygen -s Doxyfile.