/*
This function will recover the disk and then attempt to put any recovered data on that
recovered disk
@param int disk - disk to recover
@return void
*/
void recoverDisk(int disk){
// If RAID 0 do nothing besides calling the recover function
disk_array_recover_disk(diskArray, disk);
//Level 10
if (level == 10){
int diskToCopyFrom;
// To determine if recovered disk is first or second in a pair of mirrored disks
if (disk % 2){
diskToCopyFrom = disk - 1;
} else{
diskToCopyFrom = disk + 1;
}
int i;
for (i = 0; i < blockSize; i++){
char buffer[BLOCK_SIZE];
disk_array_read(diskArray, diskToCopyFrom, i, buffer);
disk_array_write(diskArray, disk, i, buffer);
}
}
//Level 4 or 5 do the same attempts at recovery
else if (level == 4 || level == 5){
int i;
char missingData [BLOCK_SIZE];
for (i = 0; i < blockSize; i++){
if(calculateXOR(disk,i, missingData) == -1){
return;
}
disk_array_write(diskArray, disk, i, missingData);
}
}
}
/**
* This function handles striping across the disks
*/
static int stripper(int size, int lba, char* value, short isWrite) {
int rc = 0;
short startFound = 0;
int diskIndex = 0;
int blockIndex = 0; //index of block within disk
int i;
short write_error = 0;
//loop until address reached
for(i = 0; i < size + lba; i++){
if(i == lba){
startFound = 1;
}
//if address reached perform read or write
if(startFound == 1){
if(isWrite == 1){
//has the disk failed?
if(disk_active[diskIndex] == 0) {
write_error = 1;
}
disk_array_write(_da, diskIndex, blockIndex, value);
}
//Read operation
else {
disk_array_read(_da, diskIndex, blockIndex, buffer);
//if bad disk print error message
if(!disk_active[diskIndex]) {
printf("ERROR ");
}
else {
printf("%d ", *((int*)buffer)); //print output from read
}
}
} //end if start found
//if reached end of strip change disk
if(++blockIndex % _strip == 0) {
diskIndex += 1;
if(diskIndex % _disk == 0) {
diskIndex = 0;
}
else {
blockIndex -= _strip;
}
}
} //end size+lba for loop
diskIndex = diskIndex % _disk;
//inform user of write error
if(write_error){
printf("ERROR ");
write_error = 0;
}
return rc;
}
/*
This function will write to the disk array starting at lba, for size, and will write
the pattern in the buff passed into the block
@param int lba - logical block address
@param int size - size of the write
@param char *buff - buffer to write to each block of the disk array
@return void
*/
void writeToArray(int lba, int size, char * buff){
//Level 0
if (level == 0) {
int currentDisk, currentBlock;
getPhysicalBlock(disks, lba, ¤tDisk, ¤tBlock);
//successfulWrite should be 0 after all writing is complete, otherwise print error
//Only want to print error once
int successfulWrite = 0;
while (size > 0) {
successfulWrite += disk_array_write(diskArray, currentDisk, currentBlock, buff);
lba ++;
getPhysicalBlock(disks, lba, ¤tDisk, ¤tBlock);
size --;
}
if (successfulWrite != 0) {
fprintf(stdout, "ERROR ");
}
}
//Level 10
else if(level == 10){
int currentDisk, currentBlock;
getPhysicalBlock(disks, lba, ¤tDisk, ¤tBlock);
currentDisk *= 2;
//successfulWrite should be 0 after all writing is complete
// Only want to print error once
int successfulWrite = 0;
while (size > 0) {
// Status keeps track of if write to disk succeded
// If we fail both, status will equal -2
int status = disk_array_write(diskArray, currentDisk, currentBlock, buff);
status += disk_array_write(diskArray, currentDisk + 1, currentBlock, buff);
if (status == -2){
successfulWrite = -1;
}
lba ++;
getPhysicalBlock(disks, lba, ¤tDisk, ¤tBlock);
currentDisk *= 2;
size--;
}
if (successfulWrite != 0) {
fprintf(stdout, "ERROR ");
}
}
//Level 4
else if(level == 4){
// successfulWrite should be 0 after all writing is complete
// Only want to print error once
int successfulWrite = 0;
int currentDisk, currentBlock;
int stripeLength =(disks - 1)*strip;
int i, j, k;
char temp[BLOCK_SIZE];
char parityChange[BLOCK_SIZE];
while (size > 0) {
int whereInStripe = lba % stripeLength;
int startOfThisStripe = lba - whereInStripe;
int blockOffsetOfThisStripe = (startOfThisStripe)/(disks-1);
int coverTo = whereInStripe + size;
int tempNum;
for(i = 0; i < strip; i ++){
for (j = 0; j < BLOCK_SIZE; j++) {
parityChange[j] = 0;
}
tempNum = i;
//printf("i: %i\n", i);
currentBlock = i + blockOffsetOfThisStripe;
while(tempNum < stripeLength){
//printf("temp: %i\n", tempNum);
currentDisk = tempNum / strip;
if(tempNum >= whereInStripe && tempNum < coverTo){
if (disk_array_write(diskArray, currentDisk, currentBlock, buff)){
successfulWrite --; //write failed
}
for (k = 0; k < BLOCK_SIZE; k++) {
parityChange[k] = parityChange[k] ^ buff[k];
}
}
else{
if (disk_array_read(diskArray, currentDisk, currentBlock, temp) != 0) {
//error reading old data, which means we cannot update parity for this block
}
else{
for (k = 0; k < BLOCK_SIZE; k++) {
parityChange[k] = parityChange[k] ^ temp[k];
}
}
}
tempNum += strip;
}
disk_array_write(diskArray, disks-1, currentBlock, parityChange);
//printf("parity %i is %i\n", i, *((int*)parityChange));
}
int next = startOfThisStripe + stripeLength;
size -= next - lba;
lba = next;
}
if (successfulWrite != 0) {
fprintf(stdout, "ERROR ");
}
}
//Level 5
else if(level == 5){
// successfulWrite should be 0 after all writing is complete
// Only want to print error once
int successfulWrite = 0;
int currentDisk, currentBlock;
int stripeLength =(disks - 1)*strip;
int i, j, k;
int currentParityDisk;
char temp[BLOCK_SIZE];
char parityChange[BLOCK_SIZE];
while (size > 0) {
int whereInStripe = lba % stripeLength;
int startOfThisStripe = lba - whereInStripe;
int blockOffsetOfThisStripe = (startOfThisStripe)/(disks-1);
int coverTo = whereInStripe + size;
int tempNum;
for(i = 0; i < strip; i ++){
for (j = 0; j < BLOCK_SIZE; j++) {
parityChange[j] = 0;
}
tempNum = i;
//printf("i: %i\n", i);
currentBlock = i + blockOffsetOfThisStripe;
currentParityDisk = (currentBlock/strip) % disks;
while(tempNum < stripeLength){
//printf("temp: %i\n", tempNum);
currentDisk = tempNum / strip;
if (currentDisk >= currentParityDisk) {
currentDisk ++;
}
if(tempNum >= whereInStripe && tempNum < coverTo){
if (disk_array_write(diskArray, currentDisk, currentBlock, buff)){
successfulWrite --; //write failed
}
for (k = 0; k < BLOCK_SIZE; k++) {
parityChange[k] = parityChange[k] ^ buff[k];
}
}
else{
if (disk_array_read(diskArray, currentDisk, currentBlock, temp) != 0) {
//error reading old data, which means we cannot update parity for this block
}
else{
for (k = 0; k < BLOCK_SIZE; k++) {
parityChange[k] = parityChange[k] ^ temp[k];
}
}
}
tempNum += strip;
}
disk_array_write(diskArray, currentParityDisk, currentBlock, parityChange);
//printf("parity %i is %i\n", i, *((int*)parityChange));
}
int next = startOfThisStripe + stripeLength;
size -= next - lba;
lba = next;
}
if (successfulWrite != 0) {
fprintf(stdout, "ERROR ");
}
}
//Error
else{
errorMsgParse();
}
}