//initializes the root directory
void init_root_dir(){
dir_entry_t *buffer = malloc(ADJUST(MAX_FILES*sizeof(dir_entry_t)));
if(buffer == NULL){
return;
}
int i;
for(i = 0; i < MAX_FILES; i++){
//set up directory values
buffer[i] = (dir_entry_t){.name = "\0",.inode_idx = LIMIT};
}
write_blocks(2, DIRECTORY_SIZE, buffer);
free(buffer);
return;
}
//method to create "free" list
void init_free_list(){
unsigned int *buffer = malloc(BLOCK_SIZE);
if (buffer == NULL){
return;
}
int i;
for(i = 0; i < (BLOCK_SIZE)/sizeof(unsigned int); i++){
//sets all bits to 1
buffer[i] = ~0;
}
write_blocks(1, FREELIST_SIZE, buffer);
free(buffer);
return;
}
int get_blk_pointer(blk_pointers_t* pointers, int blknum)
{
int indirect_pointers[BLKSIZ/BLKPOINTERSIZ];
// If blk num is for a direct pointer
if(blknum < NUMDIRECTPOINTERS) {
if(pointers->direct[blknum] == 0) {
if( (pointers->direct[blknum] = get_free_datablock()) == 0) return -1;
}
return pointers->direct[blknum];
}
// If block num is the first indirect pointer entry
if(pointers->indirect == 0) {
if( (pointers->indirect = get_free_datablock()) == 0) return -1;
memset(indirect_pointers, 0, BLKSIZ);
write_blocks(pointers->indirect, 1, (void*)indirect_pointers);
}
// If block num is an indirect pointer entry that is not the first
read_blocks(pointers->indirect, 1, (void*)indirect_pointers);
if(indirect_pointers[blknum - NUMDIRECTPOINTERS] == 0) {
if( (indirect_pointers[blknum - NUMDIRECTPOINTERS] = get_free_datablock()) == 0) return -1;
write_blocks(pointers->indirect, 1, (void*)indirect_pointers);
}
return indirect_pointers[blknum - NUMDIRECTPOINTERS];
}
void free_blk_pointers(blk_pointers_t* pointers)
{
int indirect_pointers[BLKSIZ/BLKPOINTERSIZ];
char bitmap[BLKSIZ];
int db_index, blk_num=0;
read_blocks(DBBITMAPADD, 1, bitmap);
for(blk_num = 0; blk_num <= NUMDIRECTPOINTERS; blk_num++) {
db_index = pointers->direct[blk_num];
if(db_index == 0) {
write_blocks(DBBITMAPADD, 1, bitmap);
return;
}
db_index -= DBSTARTADD;
bitmap[db_index] = FREE;
}
read_blocks(pointers->indirect, 1, (void*)indirect_pointers);
for(blk_num = 0; blk_num < BLKSIZ/BLKPOINTERSIZ; blk_num++) {
db_index = indirect_pointers[blk_num];
if(db_index == 0) {
write_blocks(DBBITMAPADD, 1, bitmap);
return;
}
db_index -= DBSTARTADD;
bitmap[db_index] = FREE;
}
}
void testfs_close_super_block(struct super_block *sb) {
testfs_tx_start(sb, TX_UMOUNT);
// write sb->sb of type dsuper_block to disk at offset 0.
testfs_write_super_block(sb);
// assume there are no entries in the inode hash table.
// delete the 256 hash size inode hash table
inode_hash_destroy();
if (sb->inode_freemap) {
// write inode map to disk.
write_blocks(sb, bitmap_getdata(sb->inode_freemap),
sb->sb.inode_freemap_start, INODE_FREEMAP_SIZE);
// free in memory bitmap file.
bitmap_destroy(sb->inode_freemap);
sb->inode_freemap = NULL;
}
if (sb->block_freemap) {
// write inode freemap to disk
write_blocks(sb, bitmap_getdata(sb->block_freemap),
sb->sb.block_freemap_start, BLOCK_FREEMAP_SIZE);
// destroy inode freemap
bitmap_destroy(sb->block_freemap);
sb->block_freemap = NULL;
}
testfs_tx_commit(sb, TX_UMOUNT);
fflush(sb->dev);
fclose(sb->dev);
sb->dev = NULL;
// free in memory data structure sb superblock
free(sb);
}
int sfs_remove(char *file) {
int i, k, j, l;
for (i=0;i<=MAX_INODES;i++){
//File exists
if(!strcmp(rootDirectory.entry[i].name, file)){
//Checks if file is open
for (k = 0;k<MAXOPENFILES;k++){
if (!strcmp((*fileDescriptorTable).entry[k].name, file)){
printf("File is open, closing....\n");
sfs_fclose(k);
break;
}
}
//Free and zero the blocks that the dataptrs attached to the file's INode point to
for (j = 0;j<NUM_DATA_POINTERS;j++){
if (rootDirectory.entry[i].inode.dataPointers[j] == 0) break;
//Frees the block in the freeBlock Array and the dataptr in the rootDirectory inode for the file
freeBlocks.freeBlocks[rootDirectory.entry[i].inode.dataPointers[j]] = 0;
freeBlocks.numberFree++;
rootDirectory.entry[i].inode.dataPointers[j] = 0;
}
rootDirectory.entry[i].inode.size = 0;
rootDirectory.entry[i].name[0] = '\0';
write_blocks(1,1,&rootDirectory);
write_blocks(MAX_BLOCKS-1, 1, &freeBlocks);
//return 0 if successful
return 0;
}
}
printf("File doesn't exist, can't delete a file that doesn't exist\n");
return -1;
}
int createINode( long mode, long linkCnt, long uid, long gid, long size){
iNode newFileINode;
newFileINode.mode = mode;
newFileINode.linkCnt = linkCnt;
newFileINode.uid = uid;
newFileINode.gid = gid;
newFileINode.size = size;
//Calculate the number of blocks required from the size:
int numBlocksToAllocate = size/BLOCKSIZE + 1;
if(numBlocksToAllocate>(12+BLOCKSIZE/4)){
//If the file is too large to be allocated
printf("%s\n", "File too large to be created");
return -1;
}
if(numBlocksToAllocate>=12){
//In this case we need to use indirect pointers
indirectINode indirect;
newFileINode.indirectPointer = allocateFreeBlock();
while(numBlocksToAllocate>=12){
//allocate using indirect pointers
indirect.pointers[numBlocksToAllocate] = allocateFreeBlock();
numBlocksToAllocate--;
}
//Write the indirect INode to disk;
unsigned char buffer[512];
memcpy(buffer,&indirect,512);
write_blocks(newFileINode.indirectPointer,1,buffer);
}
else {
newFileINode.indirectPointer = FREE;
}
int i;
for(i=0;i<12;i++){
if(numBlocksToAllocate>0){
newFileINode.directPointers[i] = allocateFreeBlock();
numBlocksToAllocate--;
}
else{
newFileINode.directPointers[i] = FREE;
}
}
int numI = findEmptyINode();
unsigned char blockBuffer[512];
//Reading the corresponding block from disk
read_blocks(findINodeBlockAddress(numI),1,&blockBuffer);
//add the buffer containing the iNode to the block
memcpy((void*)(blockBuffer+findINodeByteAddress(numI)),&newFileINode,sizeof(newFileINode));
write_blocks(findINodeBlockAddress(numI),1,&blockBuffer);
return numI;
}
int updateDisk(){
buffer = (char *) malloc(1024);
memcpy(buffer, directory, 1024);
write_blocks(0, 1, buffer);
memcpy(buffer, FAT, 1024);
write_blocks(1, 1, buffer);
memcpy(buffer, free_list, 1024);
write_blocks(1023, 1, buffer);
return 0;
}
int sfs_write(int fileID, char *buf, int length){
if(fdt[fileID][open] == false) return -1;
if(fileID > MAX_NUM_FILES || fileID < 0) return -1;
int fatEntry = files[fileID].fatIndex;
//if this is the first time writing to this file, give it a fat index
if(fat[fatEntry][block_index] == unused){
fat[fatEntry][block_index] = list_shift_int(free_blocks);
fat[fatEntry][next] = eof;
}
//we must find the block where the file ends
int numWrittenBlocks = files[fileID].size / BLOCK_SIZE;
int i;
for(i=0; i < numWrittenBlocks; i++)
fatEntry = fat[fatEntry][next];
//need to append to the rest of this block
char block[BLOCK_SIZE];
read_blocks(fat[fatEntry][block_index], 1, block);
int numBytes;
if (length < (BLOCK_SIZE - fdt[fileID][write_ptr] % BLOCK_SIZE))
numBytes = length;
else
numBytes = BLOCK_SIZE - fdt[fileID][write_ptr] % BLOCK_SIZE;
memcpy(block + (fdt[fileID][write_ptr] % BLOCK_SIZE), buf, numBytes);
write_blocks(fat[fatEntry][block_index], 1, block);
fdt[fileID][write_ptr] += numBytes;
int numBytesWritten = numBytes;
//now we can write entire blocks until no more bytes need to be
//written
while(numBytesWritten < length){
fat[fatEntry][next] = firstFreeFat();
fatEntry = fat[fatEntry][next];
fat[fatEntry][block_index] = list_shift_int(free_blocks);
fat[fatEntry][next] = eof;
write_blocks(fat[fatEntry][block_index], 1, buf+numBytesWritten);
if((length - numBytesWritten) >= BLOCK_SIZE){
numBytesWritten +=BLOCK_SIZE;
fdt[fileID][write_ptr] +=BLOCK_SIZE;
}
else{
numBytesWritten += length-numBytesWritten;
fdt[fileID][write_ptr] += length-numBytesWritten;
}
}
//update sizes and pointers and write file system blocks to disk
files[fileID].size += numBytesWritten;
write_fs_blocks();
return numBytesWritten;
}
//=======================================================================================
//==============================PRIMARY API FUNCTIONS====================================
//=======================================================================================
void mksfs(int fresh){
buffer = (void*) malloc(BLOCK_SIZE);
memset(buffer,0,BLOCK_SIZE);
if (fresh){ //FORMAT VIRTUAL DISK, CREATE NEW FROM SCRATCH
init_fresh_disk(FILESYSTEM, BLOCK_SIZE, FILESYSTEM_SIZE);
//=========Storing sb in-memory===========
sb = (superblock){0, BLOCK_SIZE, FILESYSTEM_SIZE, MAX_FD, 0};
memcpy(buffer, &sb, sizeof(superblock));
//========Storing sb on-disk==============
write_blocks(0, 1, buffer);
//========Initializing Bitmap block=======
unsigned int bit_row = 4294967295; //Row consisting of 32 '1' bits
for (int i = 0; i<256; i++){
bitmap[i] = bit_row; //Filling table with 1's (1 means block is free)
}
/*We use the first 3 blocks to store the Root Directory mapping table*/
bitmap[0] = bitmap[0] << 3;
write_blocks(1, 1, bitmap);
//========Storing inode table on-disk=====
//inode inode_table[MAX_FD+1];
for (int i = 0; i <= MAX_FD; i++){
inode_table[i] = (inode){0, 1, 1, 0, {-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1}, -1};
if (i == 0) { //First inode is root dir inode.
//It spans 3 blocks of data -> first three blocks in the datablock section
inode_table[i] = (inode){0,1,1,3,{FIRST_DB,FIRST_DB+1,FIRST_DB+2,-1,-1,-1,-1,-1,-1,-1,-1,-1},-1};
}
memcpy(buffer, &(inode_table[i]), sizeof(inode));
write_blocks(i+2, 1, buffer);
}
//====Initializing rootdir in-memory======
for (int i = 0; i < MAX_FD; i++){
root[i] = (dir){"", -1};
}
//====Initializing rootdir on-disk========
free(buffer);
buffer = (void*) malloc(BLOCK_SIZE*3);
memset(buffer,0,BLOCK_SIZE*3);
memcpy(buffer, &root, 3*BLOCK_SIZE);
write_blocks(MAX_FD+3, 3, buffer);
//====Initializing fd table in-memory=====
for (int i = 0; i < MAX_FD; i++)
fd_table[i] = (fd){1,-1,-1,-1}; //mark all entries in fd_table as empty (flag = 1 means empty)
} else {
init_disk(FILESYSTEM, BLOCK_SIZE, FILESYSTEM_SIZE);
}
free(buffer);
}
//Checks if pointer_index is initialized, and if it isn't it initializes it to the first free block
//returns -1 if failure, and block number in the sfs on success
int fetch_block(int inode, int pointer_index){
int freeblock;
//Procedure for direct pointers
if (pointer_index < 12){
if (inode_table[inode].pointer[pointer_index] == -1){ //if the pointer is NOT initialized
freeblock = get_first_freeblock();
if(freeblock){
inode_table[inode].pointer[pointer_index] = freeblock; //initialize to first free block
} else {
return -1;
}
}
return inode_table[inode].pointer[pointer_index];
//Procedure for indirect pointers
} else if (pointer_index < 268){ //256 indirect pointers + 12 direct = 268
int indir_ptr[256];
//If indirect pointer block is not initialized
if (inode_table[inode].indirect_pntr == -1){
freeblock = get_first_freeblock();
if(freeblock){
inode_table[inode].indirect_pntr = freeblock; //initialize indirect pointer to first free block
//initialize all indirect pointer to -1
for (int i = 0; i < 256; i++){
indir_ptr[i] = -1;
}
write_blocks(inode_table[inode].indirect_pntr, 1, indir_ptr); //flush the indirect pointer block
} else {
return -1;
}
}
//fetch the indirect pointer
read_blocks(inode_table[inode].indirect_pntr,1,indir_ptr);
int indir_ptr_index = pointer_index - 12;
if (indir_ptr[indir_ptr_index] == -1){ //if the indirect pointer is not initialized
freeblock = get_first_freeblock();
if (freeblock){
indir_ptr[indir_ptr_index] = freeblock; //initialize to first free block
write_blocks(inode_table[inode].indirect_pntr, 1, indir_ptr); //flush the indirect pointer block
} else {
return -1;
}
}
return indir_ptr[indir_ptr_index];
//Pointer out of bound
} else {
printf("File too large, cannot initialize new pointer\n");
return -1;
}
}
int sfs_fwrite(int fileID, const char *buf, int length){
int numINode = fileDescTable[fileID].iNode;
int writePointer = fileDescTable[fileID].RWPointer;
unsigned char blockBuffer[512];
read_blocks(findINodeBlockAddress(numINode),1,&blockBuffer);
iNode fileINode;
//memcpy((void*)(blockBuffer+findINodeByteAddress(numI)),buffer,sizeof(newFileINode));
memcpy(&fileINode,(void*)(blockBuffer+findINodeByteAddress(numINode)),sizeof(iNode));
if((writePointer+length)>fileINode.size){
//grow file
int sizeToAllocate = (writePointer+length)-fileINode.size;
int blocksToAllocate = ceil(((double)(writePointer+length))/(double)BLOCKSIZE);
int blocksAlreadyAllocated = ceil (((double)fileINode.size)/(double)BLOCKSIZE);
if((blocksAlreadyAllocated+blocksAlreadyAllocated)>(12+BLOCKSIZE/4)){
printf("File too large to be written");
return -1;
}
int i;
indirectINode indirect;
for(i=blocksAlreadyAllocated;i<blocksToAllocate;i++){
if(blocksAlreadyAllocated<12){
fileINode.directPointers[blocksAlreadyAllocated]=allocateFreeBlock();
}
else if(blocksAlreadyAllocated==12 && fileINode.indirectPointer==0){
fileINode.indirectPointer = allocateFreeBlock();
indirect.pointers[blocksAlreadyAllocated]=allocateFreeBlock();
}
else{
indirect.pointers[blocksAlreadyAllocated]=allocateFreeBlock();
}
}
//write indirect inode
if(blocksAlreadyAllocated>11){
memcpy(blockBuffer,&indirect,sizeof(indirect));
write_blocks(fileINode.indirectPointer,1,&blockBuffer);
}
//Write direct inode
fileINode.size+=sizeToAllocate;;
memcpy(blockBuffer,&fileINode,sizeof(fileINode));
write_blocks(findINodeBlockAddress(numINode),1,&blockBuffer);
}
//Write
return 0;
}
int mksfs(int fresh)
{
super_block spr_block;
char buff[BLKSIZ];
int i;
// Initialize fd_table
for(i = 0; i < MAXOPENFILES; i++)
fd_table[i].status = FREE;
if(fresh)
{
// Initialize and write super block to disk
init_fresh_disk(DISKIMG, BLKSIZ, BLOCKNUM);
spr_block.magic_number = MAGICNUM;
spr_block.block_size = BLKSIZ;
spr_block.fs_size = BLOCKNUM;
spr_block.inode_tbl_length = INODETBLSIZ;
spr_block.root_inode = ROOTINODENUM;
write_blocks(SUPERBLOCKADD, 1, (void*) &spr_block);
// Setup datablock bitmap
memset(buff, FREE, BLKSIZ);
write_blocks(DBBITMAPADD, 1, buff);
// Setup INODE Bitmap and allocate first i-node entry to root directory
buff[ROOTINODENUM] = USED;
write_blocks(INBITMAPADD, 1, buff);
// Allocate fd to root directory
fd_table[ROOTFD].status = USED;
fd_table[ROOTFD].inode_num = ROOTINODENUM;
fd_table[ROOTFD].rw_pointer = 0;
fd_table[ROOTFD].inode = (inode_struct*) calloc(1, sizeof(inode_struct));
fd_table[ROOTFD].inode->size = 0;
write_inode_by_index(fd_table[ROOTFD].inode_num, fd_table[ROOTFD].inode);
} else
{
init_disk(DISKIMG, BLKSIZ, BLOCKNUM);
fd_table[ROOTFD].status = USED;
fd_table[ROOTFD].inode_num = ROOTINODENUM;
fd_table[ROOTFD].inode = get_inode_by_index(ROOTINODENUM);
fd_table[ROOTFD].rw_pointer = fd_table[ROOTFD].inode->size;
}
return 0;
}
void initializeFreeBitMap(){
//Compute the number of blocks required for the free block bit map:
int blocksReq = (NUMBEROFBLOCKS+(BLOCKSIZE-1))/(BLOCKSIZE); //Adding blockSize to roundup.
//We are going to write 1s in every bit
unsigned char buffer[512];
memset(buffer,FREE,512);
//Compute start block:
int currentBlock = NUMBEROFBLOCKS-blocksReq;
for(currentBlock;currentBlock<NUMBEROFBLOCKS;currentBlock++){
write_blocks(currentBlock,1,&buffer);
}
//Write the blocks for SB and I-Node table as occupied
int numBlocksReqForINodes = (NUMBEROFINODES * sizeof(iNode) + (BLOCKSIZE-1))/BLOCKSIZE;
int i;
for(i=0;i<1+numBlocksReqForINodes;i++){
changeBlockStatus(i,IN_USE);
}
//Write the blocks of the free bit map as occupied:
for(i=NUMBEROFBLOCKS-1;i>=NUMBEROFBLOCKS-blocksReq;i--){
changeBlockStatus(i,IN_USE);
}
}
void mksfs(int fresh) {
if (fresh == 1){
//Makes a new disk if fresh flag is true
printf("Initializing disk\n");
init_fresh_disk(DISK,BLOCK_SIZE,MAX_BLOCKS);
fillWithZeroes();
//calloc for fdt
fileDescriptorTable = (FileDescriptorTable*)calloc(1,sizeof(FileDescriptorTable));
//Write superblock
printf("Writing superblock\n");
//setupSuperblock(superBlock);
printf("Setting up superblock\n");
write_blocks(0,1,&superBlock);
//Write root directory
bzero(&rootDirectory,sizeof(Directory));
printf("Writing root directory\n");
write_blocks(1,1, &rootDirectory);
//Write free blocks
printf("Writing free blocks\n");
freeBlocks.numberFree = MAX_BLOCKS;
freeBlocks.freeBlocks[0] = 1; //superblock
freeBlocks.numberFree--;
freeBlocks.freeBlocks[1] = 1; //root directory
freeBlocks.numberFree--;
freeBlocks.freeBlocks[MAX_BLOCKS-1] = 1; //free_blocks;
freeBlocks.numberFree--;
//Write free blocks to disk
printf("writing free blocks to disk \n");
write_blocks(MAX_BLOCKS - 1, 1, &freeBlocks);
}else{
printf("Loading disk\n");
//Pull disk data into memory
init_disk(DISK, BLOCK_SIZE, MAX_BLOCKS);
}
//Initializes variable for sfs_getnextfilename;
sfsGetNextIndex = 0;
//Initializes variable for fileDescriptor table
(*fileDescriptorTable).firstOpenIndex = 0;
(*fileDescriptorTable).size = 0;
//Initializes variable for rootDirectory
rootDirectory.firstOpenIndex = 2;
rootDirectory.size = 3;
return;
}
/*
* from in memory data structure sb, copy dsuper_block
* into buffer block. then send it for writing to write_blocks
*/
void testfs_write_super_block(struct super_block *sb) {
char block[BLOCK_SIZE] = { 0 };
assert(sizeof(struct dsuper_block) <= BLOCK_SIZE);
sb->sb.modification_time = time(NULL);
_memcpy(block, &sb->sb, sizeof(struct dsuper_block));
write_blocks(sb, block, 0, 1);
}
int testfs_write_data(struct inode *in, const char *buf, off_t start, size_t size) {
char block[BLOCK_SIZE];
long block_nr = start / BLOCK_SIZE;
long block_ix = start % BLOCK_SIZE;
int ret;
if (block_ix + size > BLOCK_SIZE) {
if ((ret = testfs_allocate_block(in, block_nr, block)) < 0)
return ret;
memcpy(block + block_ix, buf, BLOCK_SIZE - block_ix);
write_blocks(in->sb, block, ret, 1);
long size_remaining = size - (BLOCK_SIZE - block_ix);
int i = 1;
while(size_remaining > BLOCK_SIZE){
if ((ret = testfs_allocate_block(in, block_nr + i, block)) < 0)
return ret;
memcpy(block, buf + (BLOCK_SIZE * i) - block_ix, BLOCK_SIZE);
write_blocks(in->sb, block, ret, 1);
i++;
size_remaining -= BLOCK_SIZE;
}
if ((ret = testfs_allocate_block(in, block_nr + i, block)) < 0) {
in->in.i_size = 34376597504;
in->i_flags |= I_FLAGS_DIRTY;
return ret;
}
memcpy(block, buf + (BLOCK_SIZE * i) - block_ix, size_remaining);
write_blocks(in->sb, block, ret, 1);
if (size > 0)
in->in.i_size = MAX(in->in.i_size, start + (off_t) size);
in->i_flags |= I_FLAGS_DIRTY;
return size;
}
/* ret is the newly allocated physical block number */
ret = testfs_allocate_block(in, block_nr, block);
if (ret < 0)
return ret;
memcpy(block + block_ix, buf, size);
write_blocks(in->sb, block, ret, 1);
/* increment i_size by the number of bytes written. */
if (size > 0)
in->in.i_size = MAX(in->in.i_size, start + (off_t) size);
in->i_flags |= I_FLAGS_DIRTY;
/* return the number of bytes written or any error */
return size;
}
void clearINode(int numI){
unsigned char blockBuffer[512];
//Reading the corresponding block from disk
read_blocks(findINodeBlockAddress(numI),1,&blockBuffer);
iNode fileINode;
memcpy(&fileINode,(void*)(blockBuffer+findINodeByteAddress(numI)),sizeof(fileINode));
fileINode.mode = 0;
fileINode.linkCnt = 0;
fileINode.uid = 0;
fileINode.gid = 0;
fileINode.size = 0;
int i;
for(i=0;i<12;i++){
if(fileINode.directPointers[i]!=0){
changeBlockStatus(fileINode.directPointers[i],FREE);
fileINode.directPointers[i]=0;
}
}
if(fileINode.indirectPointer!=0){
//Read the indirect block
read_blocks(fileINode.indirectPointer,1,&blockBuffer);
indirectINode indirect;
memcpy(&indirect,blockBuffer,BLOCKSIZE);
for(i=0;i<BLOCKSIZE/4;i++){
if(indirect.pointers[i]!=0){
changeBlockStatus(indirect.pointers[i],FREE);
}
}
//Zero out the indirect block
unsigned char emptyBlock[512];
memset(&emptyBlock,0,512);
write_blocks(fileINode.indirectPointer,1,&emptyBlock);
fileINode.indirectPointer=0;
}
//Make sure to clear and release memory blocks
memcpy((void*)(blockBuffer+findINodeByteAddress(numI)),&fileINode,sizeof(fileINode));
write_blocks(findINodeBlockAddress(numI),1,&blockBuffer);
}
static void
testfs_write_super_block(struct super_block *sb)
{
char block[BLOCK_SIZE] = { 0 };
assert(sizeof(struct dsuper_block) <= BLOCK_SIZE);
memcpy(block, &sb->sb, sizeof(struct dsuper_block));
write_blocks(sb, block, 0, 1);
}
void
zero_blocks(struct super_block *sb, int start, int nr)
{
int i;
for (i = 0; i < nr; i++) {
write_blocks(sb, zero, start + i, 1);
}
}
int flush_to_disk(int file_inode, int options) {
/*OPTIONS:
(0) Flush everything (Bitmap Table, Root Directory table, Inode of specified file) to the disk
(1) Flush Root Directory and Inode of specified file to the disk
(2) Flush Bitmap table and Inode of specified file*/
buffer = (void*) malloc(BLOCK_SIZE);
//Flushing Inode
memcpy(buffer, &(inode_table[file_inode]), sizeof(inode));
write_blocks(file_inode+2, 1, buffer);
free(buffer);
if (options == 0){
//Flushing root directory table
buffer = (void*) malloc(BLOCK_SIZE*3);
memset(buffer,0,BLOCK_SIZE*3);
memcpy(buffer, &root, 3*BLOCK_SIZE);
write_blocks(MAX_FD+3, 3, buffer);
free(buffer);
//Flushing bit map table
buffer = (void*) malloc(BLOCK_SIZE);
memcpy(buffer, &bitmap, BLOCK_SIZE);
write_blocks(1, 1, buffer);
free(buffer);
return 0;
} else if (options == 1){
//Flushing root directory table
buffer = (void*) malloc(BLOCK_SIZE*3);
memset(buffer,0,BLOCK_SIZE*3);
memcpy(buffer, &root, 3*BLOCK_SIZE);
write_blocks(MAX_FD+3, 3, buffer);
free(buffer);
return 0;
} else if (options == 2){
//Flushing bit map table
buffer = (void*) malloc(BLOCK_SIZE);
memcpy(buffer, &bitmap, BLOCK_SIZE);
write_blocks(1, 1, buffer);
free(buffer);
return 0;
} else{
printf("Please specify option 1, 2, or 3\n");
return -1;
}
}
static void testfs_write_block_freemap(struct super_block *sb, int block_nr) {
char *freemap;
int nr;
assert(sb->block_freemap);
freemap = bitmap_getdata(sb->block_freemap);
nr = block_nr / (BLOCK_SIZE * BITS_PER_WORD);
write_blocks(sb, freemap + (nr * BLOCK_SIZE),
sb->sb.block_freemap_start + nr, 1);
}
int mksfs(int fresh) {
int diskinit;
//Create a new filesystem if the fresh variable is set
if(fresh==1){
diskinit = init_fresh_disk(FILESYSTEMNAME, BLOCKSIZE, NUMBEROFBLOCKS);
if(diskinit != 0){
//perror("Error creating disk");
exit(-1);
}
else {
//To keep the root directory in memory
initDirectory();
//Initialize SuperBlock
mySuperBlock.magic = MAGIC;
mySuperBlock.blockSize = BLOCKSIZE;
mySuperBlock.fileSystemSize = NUMBEROFBLOCKS;
mySuperBlock.iNodeTableLength = NUMBEROFINODES;
mySuperBlock.rootINode = 0;
//Use a block sized buffer
unsigned char buffer[512];
memset(buffer,255,512);
memcpy(buffer,&mySuperBlock,512);
write_blocks(0,1,buffer);
initializeFreeBitMap();
initializeFDTable();
//Now for the Inodes: initialize the first one: (for root dir)
int numRootINode = createINode(RWE, 1, ROOT_UID, ROOT_GID, 1);
readDirectory();
return 0;
}
}
//if the free variable is not set, load
else if (fresh==0) {
diskinit = init_disk(FILESYSTEMNAME, BLOCKSIZE, NUMBEROFBLOCKS);
if(diskinit != 0){
//perror("Error reading disc");
exit(-1);
}
else {
return 0;
}
}
return -1;
}
// Writing the indirect block to disk
void update_inode_pointers(int inode_index, int *array_blockptr, int num_pointers){
if(num_pointers <= INODE_POINTERS-1){
//direct pointers only 1-12
int i;
for(i=0;i<num_pointers-1;i++){
inodes[inode_index].pointers[i]=array_blockptr[i];
}
}
else{//hanles the indirect pointer
int i;
for(i=0;i<INODE_POINTERS-1;i++){
inodes[inode_index].pointers[i]=array_blockptr[i];
}
int buffer[BLOCKSIZE/sizeof(int)];
memset(buffer,0,BLOCKSIZE);
if(inodes[inode_index].pointers[INODE_POINTERS-1]!=0){
//append indirect pointer
read_blocks(inodes[inode_index].pointers[INODE_POINTERS-1],1,buffer);
int initial_number_of_indirects=get_num_pointers_inode(inode_index)-INODE_POINTERS;
int final_number_of_indirects=num_pointers-INODE_POINTERS+1;
int k;
for(k=0;k<(final_number_of_indirects-initial_number_of_indirects)-1;k++){
buffer[k+initial_number_of_indirects]=array_blockptr[(INODE_POINTERS-1)+initial_number_of_indirects+k];
}
write_blocks(inodes[inode_index].pointers[INODE_POINTERS-1],1,buffer);
}
else
{
//find a free block for indirect pointer
int free_block=findfreeblock();
inodes[inode_index].pointers[INODE_POINTERS-1]=free_block;
markfreeblock(free_block); //mark it as occupied
//write inodes pointer into that block
int j;
for(j=0;j<(num_pointers-INODE_POINTERS+1)-1;j++){
buffer[j]=array_blockptr[(INODE_POINTERS-1)+j];
}
write_blocks(free_block,1,buffer);
}
}
}
int changeBlockStatus(int blockNumber, int status){
//This method should free up a block
int correspondingChar = blockNumber%512;
int correspondingBlock = (blockNumber+511)/512;
int blockToLookUp = correspondingBlock + (NUMBEROFBLOCKS-((NUMBEROFBLOCKS+(BLOCKSIZE-1))/(BLOCKSIZE))) -1;
//printf("Blocknumber: %d correspondingChar: %d correspondingBlock: %d blockToLookUp: %d\n", blockNumber, correspondingChar,correspondingBlock,blockToLookUp);
unsigned char buffer[512];
read_blocks(blockToLookUp,1,&buffer);
buffer[correspondingChar] = status;
write_blocks(blockToLookUp,1,buffer);
return 0;
}
void write_inode_by_index(int inode_num, inode_struct* inode)
{
inode_struct *inode_array;
int blk_num, index;
char buf[BLKSIZ];
blk_num = inode_num/INPERBLK;
index = inode_num % INPERBLK;
read_blocks(INSTARTADD+blk_num, 1, buf);
inode_array = (inode_struct*)buf;
memcpy(&inode_array[index], inode, sizeof(inode_struct));
write_blocks(INSTARTADD+blk_num, 1, buf);
}
void
mono_cfg_dump_ir (MonoCompile *cfg, const char *phase_name)
{
if (cfg->gdump_ctx == NULL)
return;
cfg_debug ("=== DUMPING PASS \"%s\" ===", phase_name);
write_byte (cfg, BEGIN_GRAPH);
write_pool (cfg, create_cp_entry (cfg, (void *) phase_name, PT_STRING));
int instruction_count = label_instructions (cfg);
write_instructions (cfg, instruction_count);
write_blocks (cfg);
}
void
testfs_close_super_block(struct super_block *sb)
{
testfs_write_super_block(sb);
inode_hash_destroy();
if (sb->inode_freemap) {
write_blocks(sb, bitmap_getdata(sb->inode_freemap),
sb->sb.inode_freemap_start, INODE_FREEMAP_SIZE);
bitmap_destroy(sb->inode_freemap);
sb->inode_freemap = NULL;
}
if (sb->block_freemap) {
write_blocks(sb, bitmap_getdata(sb->block_freemap),
sb->sb.block_freemap_start, BLOCK_FREEMAP_SIZE);
bitmap_destroy(sb->block_freemap);
sb->block_freemap = NULL;
}
fflush(sb->dev);
fclose(sb->dev);
sb->dev = NULL;
free(sb);
}
int get_free_inode_num()
{
char in_bitmap[BLKSIZ];
int i;
read_blocks(INBITMAPADD, 1, in_bitmap);
for(i = 0; i < MAXINODENUM; i++) {
if(in_bitmap[i] == FREE) {
in_bitmap[i] = USED;
write_blocks(INBITMAPADD, 1, in_bitmap);
return i;
}
}
return -1;
}
int get_free_datablock()
{
char db_bitmap[BLKSIZ];
int i;
read_blocks(DBBITMAPADD, 1, db_bitmap);
for(i = 0; i < BLKSIZ; i++) {
if(db_bitmap[i] == FREE) {
db_bitmap[i] = USED;
write_blocks(DBBITMAPADD, 1, db_bitmap);
return DBSTARTADD+i;
}
}
printf("Ran out of free data blocks\n");
return 0;
}
//method to set bits to free (opposite of allocate())
void setFree(unsigned int index){
if(index > MAX_BLOCKS){
printf("Allocation error\n");
return;
}
int byte = index / (8*sizeof(unsigned int));
int bit = index % (8*sizeof(unsigned int));
unsigned int *buffer = malloc(BLOCK_SIZE);
if(buffer == NULL){
printf("Error assigning free bit\n");
return;
}
read_blocks(1, FREELIST_SIZE, buffer);
buffer[byte] |= 1 << bit;
write_blocks(1, FREELIST_SIZE, buffer);
free(buffer);
}