try to start a layer 3

This commit is contained in:
FactorialN 2023-11-19 21:23:51 -08:00
parent eb8eebc099
commit 7c82ccfa3a
6 changed files with 64 additions and 566 deletions

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.DS_Store vendored

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class fischl{
// declare
public:
int init();
};

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#include "rawdisk.h"
/*****************************************************
30GB Disk low-level operation and data structure: spuerblock, inode, and buffer cache
512 bytes sector for 1 block, 62914560 block(sector)
4K bytes sector for 1 block, 7864320 block(sector)
one inode equipped with one 512 bytes block
*****************************************************/
#define SECTOR_SIZE 512
#define IO_BLOCK_SIZE 4096
#define MAX_INODE 524288
#define MAX_BLOCKNUM MAX_INODE*2 //62914560
class SuperBlock{
public:
SuperBlock(){
}
~SuperBlock(){
}
static u_int64_t getFreeListHead(RawDisk &disk){
char buffer[8] = {0};
disk.rawdisk_read(0, buffer, sizeof(buffer));
u_int64_t t = 0;
for (int j = 0; j < 8; j++)
t = t | (((u_int64_t)(unsigned char)buffer[j])<<(8*j));
return t;
}
static void writeFreeListHead(RawDisk &disk, u_int64_t t){
char buffer[8] = {0};
for (int j = 0; j < 8; j++){
buffer[j] = (t >> (8 * j)) & 0xFF;
}
disk.rawdisk_write(0, buffer, sizeof(buffer));
}
static u_int64_t getFreeINodeHead(RawDisk &disk){
char buffer[8] = {0};
disk.rawdisk_read(8, buffer, sizeof(buffer));
u_int64_t t = 0;
for (int j = 0; j < 8; j++)
t = t | (((u_int64_t)(unsigned char)buffer[j])<<(8*j));
return t;
}
static void writeFreeINodeHead(RawDisk &disk, u_int64_t t){
char buffer[8] = {0};
for (int j = 0; j < 8; j++){
buffer[j] = (t >> (8 * j)) & 0xFF;
}
disk.rawdisk_write(8, buffer, sizeof(buffer));
}
};
class INode{
// direct datablocks
u_int64_t blocks[48];
// indirect address
u_int64_t single_indirect, double_indirect, triple_indirect;
// other
u_int64_t uid;
u_int64_t gid;
u_int64_t permissions;
u_int64_t size;
u_int64_t block_number;
public:
void read_get_byte(u_int64_t &t, int &current_pos, char *buffer){
t = 0;
for (int j = 0; j < 8; j++)
t = t | (((u_int64_t)(unsigned char)buffer[j+current_pos])<<(8*j));
current_pos += 8;
}
static u_int64_t read_byte_at(int current_pos, char *buffer){
u_int64_t t = 0;
for (int j = 0; j < 8; j++)
t = t | (((u_int64_t)(unsigned char)buffer[j+current_pos])<<(8*j));
return t;
}
void inode_construct(u_int64_t blockNumber, RawDisk &disk){
char buffer[SECTOR_SIZE] = {0};
disk.rawdisk_read(blockNumber*SECTOR_SIZE, buffer, sizeof(buffer));
block_number = blockNumber;
int current_pos = 0;
// initialize blocks
for (int i = 0; i < 48; i++){
read_get_byte(blocks[i], current_pos, buffer);
}
read_get_byte(single_indirect, current_pos, buffer);
read_get_byte(double_indirect, current_pos, buffer);
read_get_byte(triple_indirect, current_pos, buffer);
read_get_byte(uid, current_pos, buffer);
read_get_byte(gid, current_pos, buffer);
read_get_byte(permissions, current_pos, buffer);
read_get_byte(size, current_pos, buffer);
}
void write_get_byte(u_int64_t t, int &current_pos, char *buffer){
for (int j = 0; j < 8; j++){
buffer[j+current_pos] = t & (((u_int64_t)1<<(8))-1);
t >>= 8;
}
current_pos += 8;
}
static void write_byte_at(u_int64_t t, int current_pos, char *buffer){
for (int j = 0; j < 8; j++){
buffer[j+current_pos] = t & (((u_int64_t)1<<(8))-1);
t >>= 8;
}
}
void inode_save(RawDisk &disk){
char buffer[SECTOR_SIZE] = {0};
int current_pos = 0;
for (int i = 0; i < 48; i++){
write_get_byte(blocks[i], current_pos, buffer);
}
write_get_byte(single_indirect, current_pos, buffer);
write_get_byte(double_indirect, current_pos, buffer);
write_get_byte(triple_indirect, current_pos, buffer);
write_get_byte(uid, current_pos, buffer);
write_get_byte(gid, current_pos, buffer);
write_get_byte(permissions, current_pos, buffer);
write_get_byte(size, current_pos, buffer);
disk.rawdisk_write(block_number*SECTOR_SIZE, buffer, sizeof(buffer));
}
u_int64_t datablock_allocate_in_list(RawDisk &disk){
//find a free data block
u_int64_t freeListHead = SuperBlock::getFreeListHead(disk);
/*
1. initialization
2. data block starting position
3. r/w between storage and rawdisk to maintain
*/
char buffer[IO_BLOCK_SIZE] = {0};
u_int64_t freeBlockNum = 0;
disk.rawdisk_read(freeListHead, buffer, sizeof(buffer));
for (int i = 8; i < 264; i++){
if((i < 263 && buffer[i] != -1) || (i == 263 && buffer[i] != 127)){
int j = 0;
for (j = 0; j < 8; j++){
if ((buffer[i]&(1<<j)) == 0){
buffer[i] |= (1<<j);
break;
}
}
if (j < 8){
freeBlockNum = freeListHead + ((i-8)*8 + j + 1)*IO_BLOCK_SIZE;
break;
}
}
}
disk.rawdisk_write(freeListHead, buffer, sizeof(buffer));
bool notFull = false;
for (int i = 8; i < 264; i++){
if((i < 263 && buffer[i] != -1) || (i == 263 && buffer[i] != 127)){
notFull = true;
break;
}
}
if (!notFull){
printf("HEADER REMOVAL DETECTED %llu %llu\n", freeListHead, freeBlockNum);
u_int64_t next_header = read_byte_at(0, buffer);
SuperBlock::writeFreeListHead(disk, next_header);
}
return freeBlockNum;
}
bool allo_single_indirect(RawDisk &disk, u_int64_t &single_i, u_int64_t freeBlockNum) {
if (single_i == 0){
single_i = datablock_allocate_in_list(disk);
char new_buffer[IO_BLOCK_SIZE] = {0};
disk.rawdisk_write(single_i, new_buffer, sizeof(new_buffer));
}
bool inSingle = false;
char buffer[IO_BLOCK_SIZE] = {0};
disk.rawdisk_read(single_i, buffer, sizeof(buffer));
for (int i = 0; i < IO_BLOCK_SIZE; i+=8){
u_int64_t addr = read_byte_at(i, buffer);
if(addr == 0){
inSingle = true;
write_byte_at(freeBlockNum, i, buffer);
disk.rawdisk_write(single_i, buffer, sizeof(buffer));
break;
}
}
return inSingle;
}
bool allo_double_indirect(RawDisk &disk, u_int64_t &double_i, u_int64_t freeBlockNum) {
if (double_i == 0){
double_i = datablock_allocate_in_list(disk);
char new_buffer[IO_BLOCK_SIZE] = {0};
disk.rawdisk_write(double_i, new_buffer, sizeof(new_buffer));
}
bool inDouble = false;
char buffer[IO_BLOCK_SIZE] = {0};
disk.rawdisk_read(double_i, buffer, sizeof(buffer));
for (int i = 0; i < IO_BLOCK_SIZE; i+=8){
u_int64_t addr = read_byte_at(i, buffer);
bool flag = allo_single_indirect(disk, addr, freeBlockNum);
if (flag){
write_byte_at(addr, i, buffer);
disk.rawdisk_write(double_i, buffer, sizeof(buffer));
inDouble = true;
break;
}
}
return inDouble;
}
bool allo_triple_indirect(RawDisk &disk, u_int64_t &triple_i, u_int64_t freeBlockNum) {
if (triple_i == 0){
triple_i = datablock_allocate_in_list(disk);
char new_buffer[IO_BLOCK_SIZE] = {0};
disk.rawdisk_write(triple_i, new_buffer, sizeof(new_buffer));
}
bool inTriple = false;
char buffer[IO_BLOCK_SIZE] = {0};
disk.rawdisk_read(triple_i, buffer, sizeof(buffer));
for (int i = 0; i < IO_BLOCK_SIZE; i+=8){
u_int64_t addr = read_byte_at(i, buffer);
bool flag = allo_double_indirect(disk, addr, freeBlockNum);
if (flag){
write_byte_at(addr, i, buffer);
disk.rawdisk_write(triple_i, buffer, sizeof(buffer));
inTriple = true;
break;
}
}
return inTriple;
}
// allowcate 1 datablock and add to the end of the file
u_int64_t datablock_allocate(RawDisk &disk){
//do we need to check dynamic?
//add the data block to blocks, single, double, triple
u_int64_t freeBlockNum = datablock_allocate_in_list(disk);
bool inBlocks = false;
for (int i = 0; i < 48; i++)
if(blocks[i] == 0){
inBlocks = true;
blocks[i] = freeBlockNum;
break;
}
if(!inBlocks){
bool inSingle = allo_single_indirect(disk, single_indirect, freeBlockNum);
if (!inSingle){
bool inDouble = allo_double_indirect(disk, double_indirect, freeBlockNum);
if (!inDouble){
bool inTriple = allo_triple_indirect(disk, triple_indirect, freeBlockNum);
// wait to deal with too big files
}
}
}
//return the block number
inode_save(disk);
return freeBlockNum;
}
void datablock_deallocate_in_list(u_int64_t freeBlockNum, RawDisk &disk) {
// find the related 2048block head
u_int64_t freeBlockHead = ((freeBlockNum/SECTOR_SIZE-MAX_INODE)/(8*2048)*(8*2048)+MAX_INODE)*SECTOR_SIZE;
// mark it alive in its bitmap
char buffer[IO_BLOCK_SIZE] = {0};
bool nowInList = false;
disk.rawdisk_read(freeBlockHead, buffer, sizeof(buffer));
for (int i = 8; i < 264; i++){
if((i < 263 && buffer[i] != -1) || (i == 263 && buffer[i] != 127)){
nowInList = true;
}
}
u_int64_t inBlockPos = (freeBlockNum-freeBlockHead)/IO_BLOCK_SIZE-1;
buffer[8+inBlockPos/8] &= (-1)^(1<<(inBlockPos%8));
// if its bitmap was 0, add it back to the list head
if(!nowInList){
u_int64_t freeListHead = SuperBlock::getFreeListHead(disk);
write_byte_at(freeListHead, 0, buffer);
SuperBlock::writeFreeListHead(disk, freeBlockHead);
}
disk.rawdisk_write(freeBlockHead, buffer, sizeof(buffer));
}
u_int64_t deallo_single_indirect(RawDisk &disk, u_int64_t &single_i){
if (single_i == 0){
return 0;
}
u_int64_t freeBlockNum = 0;
char buffer[IO_BLOCK_SIZE] = {0};
int delpoint = -1;
disk.rawdisk_read(single_i, buffer, sizeof(buffer));
for (int i=4088; i >= 0; i-=8){
u_int64_t addr = read_byte_at(i, buffer);
if(addr != 0){
freeBlockNum = addr;
addr = 0;
write_byte_at(addr, i, buffer);
delpoint = i;
break;
}
}
disk.rawdisk_write(single_i, buffer, sizeof(buffer));
u_int64_t addr = read_byte_at(0, buffer);
if (delpoint == 0 && addr == 0){
datablock_deallocate_in_list(single_i, disk);
single_i = 0;
}
return freeBlockNum;
}
u_int64_t deallo_double_indirect(RawDisk &disk, u_int64_t &double_i){
if (double_i == 0){
return false;
}
u_int64_t freeBlockNum = 0;
char buffer[IO_BLOCK_SIZE] = {0};
int delpoint = -1;
disk.rawdisk_read(double_i, buffer, sizeof(buffer));
for (int i=4088; i >= 0; i-=8){
u_int64_t addr = read_byte_at(i, buffer);
u_int64_t inSingle = deallo_single_indirect(disk, addr);
if (inSingle){
freeBlockNum = inSingle;
write_byte_at(addr, i, buffer);
delpoint = i;
break;
}
}
disk.rawdisk_write(double_i, buffer, sizeof(buffer));
u_int64_t addr = read_byte_at(0, buffer);
if (delpoint == 0 && addr == 0){
datablock_deallocate_in_list(double_i, disk);
double_i = 0;
}
return freeBlockNum;
}
u_int64_t deallo_triple_indirect(RawDisk &disk, u_int64_t &triple_i){
if (triple_i == 0){
return false;
}
u_int64_t freeBlockNum = 0;
char buffer[IO_BLOCK_SIZE] = {0};
int delpoint = -1;
disk.rawdisk_read(triple_i, buffer, sizeof(buffer));
for (int i=4088; i >= 0; i-=8){
u_int64_t addr = read_byte_at(i, buffer);
u_int64_t inDouble = deallo_double_indirect(disk, addr);
if (inDouble){
freeBlockNum = inDouble;
write_byte_at(addr, i, buffer);
delpoint = i;
break;
}
}
disk.rawdisk_write(triple_i, buffer, sizeof(buffer));
u_int64_t addr = read_byte_at(0, buffer);
if (delpoint == 0 && addr == 0){
datablock_deallocate_in_list(triple_i, disk);
triple_i = 0;
}
return freeBlockNum;
}
// deallocate 1 datablock from the end of the file
u_int64_t datablock_deallocate(RawDisk &disk){
// find the last datablock and remove it from inode (triple->direct)
u_int64_t freeBlockNum = 0;
freeBlockNum = deallo_triple_indirect(disk, triple_indirect);
if(!freeBlockNum){
freeBlockNum = deallo_double_indirect(disk, double_indirect);
if(!freeBlockNum){
freeBlockNum = deallo_single_indirect(disk, single_indirect);
if(!freeBlockNum){
for(int i = 47; i>=0; i--)
if(blocks[i] != 0){
freeBlockNum = blocks[i];
blocks[i] = 0;
break;
}
// deal with empty
}
}
}
// add it back to freeBlocklist
datablock_deallocate_in_list(freeBlockNum, disk);
inode_save(disk);
return freeBlockNum;
}
};
class INodeOperation{
// free list head is at super block (0): first 8 bytes
public:
//initialization of the rawdisk
void initialize(RawDisk &disk){
// initialize Inode list head
SuperBlock::writeFreeINodeHead(disk, 1);
for (u_int64_t i = 1; i < MAX_INODE; i++){
char buffer[SECTOR_SIZE] = {0};
u_int64_t t = i + 1;
if (t < MAX_INODE){
for (int j = 0; j < 8; j++){
buffer[j] = (t >> (8 * j)) & 0xFF;
}
}
disk.rawdisk_write(i*SECTOR_SIZE, buffer, sizeof(buffer));
}
SuperBlock::writeFreeListHead(disk, MAX_INODE*SECTOR_SIZE); // maximum inode number 2^19 0x80000
//Have tested this initialize function but MAX_BLOCK too much, MAX_INODE*2 works
for (u_int64_t i = MAX_INODE; i < MAX_BLOCKNUM-4096; i += 2048*8){
char buffer[IO_BLOCK_SIZE] = {0};
u_int64_t t = (i + 2048*8)*SECTOR_SIZE;
//t is address, storing in to buffer
for (int j = 0; j < 8; j++){
buffer[j] = (t >> (8 * j)) & 0xFF;
}
disk.rawdisk_write(i*SECTOR_SIZE, buffer, sizeof(buffer));
}
}
// allocate an inode from free inode list head and return the number of the inode
// the i-th inode is in the i-th block
u_int64_t inode_allocate(RawDisk &disk){
u_int64_t freeINodeHead = SuperBlock::getFreeINodeHead(disk);
char buffer[SECTOR_SIZE] = {0};
disk.rawdisk_read(freeINodeHead*SECTOR_SIZE, buffer, sizeof(buffer));
u_int64_t newINodeHead = INode::read_byte_at(0, buffer);
// deal with no more INode
SuperBlock::writeFreeINodeHead(disk, newINodeHead);
//to do: initialize the INode on disk at freeINodeHead
//return inode number
return freeINodeHead;
}
// free the inode and add it to the free inode list head
void inode_free(RawDisk &disk, u_int64_t INodeNumber){
u_int64_t freeINodeHead = SuperBlock::getFreeINodeHead(disk);
char buffer[SECTOR_SIZE] = {0};
INode::write_byte_at(freeINodeHead, 0, buffer);
disk.rawdisk_write(INodeNumber*SECTOR_SIZE, buffer, sizeof(buffer));
SuperBlock::writeFreeINodeHead(disk, INodeNumber);
}
//ignore for now
void inode_read(){
}
void inode_write(){
}
};

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#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/ioctl.h>
#include <linux/fs.h>
class RawDisk{
int fd;
const char* dir;
u_int64_t numSectors;
u_int64_t diskSize;
public:
RawDisk(const char *directory) : fd(-1), dir(nullptr), numSectors(0), diskSize(0) {
dir = directory;
/*dir = strdup("/dev/vdc");
numSectors = 62914560;
diskSize = 32212254720;*/
// Open the block device (replace /dev/sdX with the actual device)
fd = open(dir, O_RDWR); // Allow read and write
if (fd == -1) {
perror("Error opening device");
exit(1);
}
// Use ioctl with BLKGETSIZE to get the number of sectors
if (ioctl(fd, BLKGETSIZE64, &diskSize) == -1) {
perror("Error getting disk size");
close(fd);
exit(1);
}
// Calculate the size in bytes
numSectors = diskSize / 512; // Assuming a sector size of 512 bytes
printf("====Initializing RawDisk====\n");
printf("Number of sectors: %llu\n", numSectors);
printf("Disk size (in bytes): %llu\n", diskSize);
}
~RawDisk() {
if (fd != -1) {
close(fd);
}
}
int rawdisk_read(u_int64_t offset, char *buffer, size_t length) {
if (lseek(fd, offset, SEEK_SET) == (u_int64_t)-1) {
perror("Error seeking to offset");
return -1;
}
ssize_t bytesRead = read(fd, buffer, length);
if (bytesRead == -1) {
perror("Error reading from device");
return -1;
}
return 0;
}
// Write a specified number of bytes at a given byte offset
int rawdisk_write(u_int64_t offset, char *buffer, size_t length) {
if (lseek(fd, offset, SEEK_SET) == (u_int64_t)-1) {
perror("Error seeking to offset");
return -1;
}
ssize_t bytesWritten = write(fd, buffer, length);
if (bytesWritten == -1) {
perror("Error writing to device");
return -1;
}
return 0;
}
};

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#include "fischl.h"
#define FUSE_USE_VERSION 31
#include <cstdio>
#include <fuse.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <assert.h>
int fischl::init(){
printf("Hello Fischl!");
return 3;
static int fischl_mkdir(const char *, mode_t) {
return 0;
}
static int fischl_open(const char *path, struct fuse_file_info *fi) {
return 0;
}
static const struct fuse_operations fischl_oper = {
.init = fischl_init,
.getattr = fischl_getattr,
.readdir = fischl_readdir,
.open = fischl_open,
.mkdir = fischl_mkdir,
.read = fischl_read,
};
static void show_help(const char *progname)
{
printf("usage: %s [options] <mountpoint>\n\n", progname);
printf("File-system specific options:\n"
" --name=<s> Name of the \"hello\" file\n"
" (default: \"hello\")\n"
" --contents=<s> Contents \"hello\" file\n"
" (default \"Hello, World!\\n\")\n"
"\n");
}
int main(int argc, char *argv[])
{
int ret;
struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
/* Parse options */
if (fuse_opt_parse(&args, &options, option_spec, NULL) == -1)
return 1;
/* When --help is specified, first print our own file-system
specific help text, then signal fuse_main to show
additional help (by adding `--help` to the options again)
without usage: line (by setting argv[0] to the empty
string) */
if (options.show_help) {
show_help(argv[0]);
assert(fuse_opt_add_arg(&args, "--help") == 0);
args.argv[0][0] = '\0';
}
ret = fuse_main(args.argc, args.argv, &hello_oper, NULL);
fuse_opt_free_args(&args);
return ret;
}

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#include "rawdisk.h"
int main(){
fischl *F = new fischl;
F->init();
fischl();
char *d = strdup("/dev/vdc");
RawDisk *H = new RawDisk(d);
return 0;