uint64_t fs_get_block(struct superblock *sb) {
if (sb->freeblks == 0) {
//report Error
return 0;
}
uint64_t freeList = sb->freelist;
struct freepage *fp = (struct freepage *) malloc(sb->blksz);
struct freepage *fp_prev = (struct freepage *) malloc(sb->blksz);
struct freepage *fp_next = (struct freepage *) malloc(sb->blksz);
seek_read(sb, freeList, fp);
if (fp->count != 0) {
//update previous pointers
seek_read(sb, fp->links[0], fp_prev);
fp_prev->next = fp->next;
seek_write(sb, fp->links[0], fp_prev);
}
if (fp->next != 0) {
//update next pointers
seek_read(sb, fp->next, fp_next);
fp_next->links[0] = fp->links[0];
seek_write(sb, fp->next, fp_next);
}
sb->freelist = fp->next;
sb->freeblks--;
seek_write(sb, 0, sb);
free(fp_prev);
free(fp);
free(fp_next);
return freeList;
}
int fs_put_block(struct superblock *sb, uint64_t block) {
if (sb->freeblks != 0) {
uint64_t freeList = sb->freelist;
struct freepage *fp = NULL, *fp_next = NULL;
fp = (struct freepage *) malloc(sb->blksz);
fp_next = (struct freepage *) malloc(sb->blksz);
seek_read(sb, freeList, fp_next);
fp->next = freeList;
fp->count = 0;
seek_write(sb, block, fp);
fp_next->count = 1;
fp_next->links[0] = block;
seek_write(sb, freeList, fp_next);
free(fp);
free(fp_next);
} else {
struct freepage *fp = NULL;
fp = (struct freepage *) malloc(sb->blksz);
fp->next = 0;
fp->count = 0;
seek_write(sb, block, fp);
free(fp);
}
sb->freelist = block;
sb->freeblks++;
seek_write(sb, 0, sb);
return 0;
}
int InsertInNode(struct superblock* sb, const char* dirName,
const uint64_t fileBlock) {
int exists;
struct inode*dirNode = NULL;
struct nodeinfo* meta = NULL;
dirNode = malloc(sb->blksz);
meta = malloc(sb->blksz);
uint64_t dirBlock = findFile(sb, dirName, &exists);
seek_read(sb, dirBlock, dirNode);
seek_read(sb, dirNode->meta, meta);
int len = 0;
char** fileparts = getFileParts(dirName, &len);
if (strcmp(meta->name, fileparts[len - 1]) != 0)return 0; //dir does not exists
if ((++meta->size) % getLinksMaxLen(sb) == 0) {
//needs to create another link block
struct inode* linknode = NULL;
linknode = malloc(sb->blksz);
linknode->links[0] = fileBlock;
linknode->links[1] = 0;
uint64_t lastLinkBlock = getNodeLastLinkBlock(sb, dirBlock);
struct inode* lastLinkNode = NULL;
lastLinkNode = malloc(sb->blksz);
seek_read(sb, lastLinkBlock, lastLinkNode);
if (lastLinkNode->next != 0) {
exit(EXIT_FAILURE);
}
lastLinkNode->next = fs_get_block(sb);
seek_write(sb, lastLinkNode->next, linknode);
seek_write(sb, lastLinkBlock, lastLinkNode);
free(linknode);
free(lastLinkNode);
} else {
int linkLen = getLinksLen(dirNode);
dirNode->links[linkLen] = fileBlock;
dirNode->links[linkLen + 1] = 0;
}
seek_write(sb, dirBlock, dirNode);
seek_write(sb, dirNode->meta, meta);
freeFileParts(&fileparts, len);
free(dirNode);
free(meta);
return FALSE;
}
int fs_close(struct superblock *sb) {
if (sb == NULL) {
return -1;
}
seek_write(sb, 0, sb);
if (flock(sb->fd, LOCK_UN | LOCK_NB) != 0) {
errno = EBADF;
return -1;
}
close(sb->fd);
free(sb);
return 0;
}
/**
* Inserts block2Add in the links relative to destBlock.
* Does not check if destBlock is valid!
* @param sb the superblock
* @param destBlock block to receive block2Add as a child
* @param block2Add block to be added in the children of destBlock
* @return as of now you can ignore this
*/
int insertInBlock(struct superblock* sb, const uint64_t destBlock,
const uint64_t block2Add) {
struct inode *dirNode = NULL;
struct nodeinfo* meta = NULL;
dirNode = malloc(sb->blksz);
meta = malloc(sb->blksz);
seek_read(sb, destBlock, dirNode);
seek_read(sb, dirNode->meta, meta);
if ((++meta->size) % getLinksMaxLen(sb) == 0) {
//needs to create another link block
struct inode* linknode = NULL;
linknode = malloc(sb->blksz);
linknode->links[0] = block2Add;
linknode->links[1] = 0;
uint64_t lastLinkBlock = getNodeLastLinkBlock(sb, destBlock);
struct inode* lastLinkNode = NULL;
lastLinkNode = malloc(sb->blksz);
seek_read(sb, lastLinkBlock, lastLinkNode);
if (lastLinkNode->next != 0) {
exit(EXIT_FAILURE);
}
lastLinkNode->next = fs_get_block(sb);
seek_write(sb, lastLinkNode->next, linknode);
seek_write(sb, lastLinkBlock, lastLinkNode);
free(linknode);
free(lastLinkNode);
} else {
int linkLen = getLinksLen(dirNode);
dirNode->links[linkLen] = block2Add;
dirNode->links[linkLen + 1] = 0;
}
seek_write(sb, destBlock, dirNode);
seek_write(sb, dirNode->meta, meta);
free(dirNode);
free(meta);
return TRUE;
}
//////////////////////////////////////////////////
//
// SND_IO_File
//
//////////////////////////////////////////////////
bool SND_IO_File::open(const char *fname)
{
if (file.is_open())
close();
file.clear();
is_valid = false;
file.open(fname, ios::in | ios::out | ios::binary);
if (!file)
return false;
if (!read_header(file)) {
file.close();
return false;
}
if (!seek_read(0) || !seek_write(0)) {
file.close();
return false;
}
is_valid = true;
return true;
}
int main(int argc, char** argv)
{
int i = 0;
if (argc == 1) {
printf("Usage: %s <filename>\n", argv[0]);
return EXIT_FAILURE;
}
signal(SIGBUS, catch_sigbus);
/* the next test should not trigger SIGBUS */
expect_sigbus = 0;
for (i = 0; i < RUN_LOOP; i++) {
seek_write(argv[1]);
}
/* the next test should trigger SIGBUS */
expect_sigbus = 1;
if (read_after_eof(argv[1]))
return EXIT_FAILURE;
return EXIT_SUCCESS;
}
int fs_mkdir(struct superblock *sb, const char *dname) {
if (!sb->freeblks) {
// disk is full
errno = ENOSPC;
return invalid;
}
int exists = 0;
uint64_t fileBlock = findFile(sb, dname, &exists);
if (exists) {
// dir already exist;
errno = EEXIST;
return invalid;
}
struct inode *father = (struct inode*) malloc(sb->blksz);
struct inode *folder = (struct inode*) malloc(sb->blksz);
struct nodeinfo *n_info = (struct nodeinfo*) malloc(sb->blksz);
uint64_t folder_block = fs_get_block(sb);
uint64_t nodeinfo_block = fs_get_block(sb);
init_folder_struct(folder, folder_block, nodeinfo_block);
int status = init_nodeinfo_struct(sb, dname, n_info, nodeinfo_block);
if (status == invalid) {
free(father);
father = NULL;
free(folder);
folder = NULL;
free(n_info);
n_info = NULL;
errno = ENAMETOOLONG;
return invalid;
}
/* Read father inode stored in file */
seek_read(sb, fileBlock, father);
status = checkfather_path(sb, dname, father);
if (status == invalid) {
free(father);
father = NULL;
free(folder);
folder = NULL;
free(n_info);
n_info = NULL;
errno = ENOENT;
return invalid;
}
/* Ok, proceed */
if (!exists) {
insertInBlock(sb, fileBlock, folder_block);
/* store both inodes related to the folder that
has been just created
*/
seek_write(sb, folder_block, folder);
seek_write(sb, nodeinfo_block, n_info);
}
free(father);
father = NULL;
free(folder);
folder = NULL;
free(n_info);
n_info = NULL;
return success;
}
int fs_delete_file(struct superblock *sb, const char *fname) { //o proprio nome ja diz.
int i = 0, found, maxLink, ultimo;
uint64_t fileBlock, fileLinkBlk, lastBlock, folderBlock; //numero do bloco e do bloco do link no diretorio que tem ele
struct inode *file;
struct inode *folder;
struct inode *aux;
struct nodeinfo *folderInfo;
maxLink = getLinksMaxLen(sb);
file = (struct inode *) malloc(sb->blksz);
folder = (struct inode *) malloc(sb->blksz);
aux = (struct inode *) malloc(sb->blksz);
folderInfo = (struct nodeinfo *) malloc(sb->blksz);
fileBlock = findFile(sb, fname, &found);
if (found == 0) { //arquivo nao existe
errno = ENOENT;
return -1;
}
seek_read(sb, fileBlock, file); //pegando inode do arquivo
if (file->mode == IMDIR) { //se for diretorio
errno = EISDIR;
return -1;
}
folderBlock = file->parent;
fileLinkBlk = folderBlock;
seek_read(sb, folderBlock, folder); //diretorio onde esta o arquivo
seek_read(sb, folder->meta, folderInfo);
//removendo o arquivo e blocos associados
fs_put_block(sb, file->meta); //liberando bloco nodeinfo
while ((i < maxLink) && (file->links[i] != 0)) {
//if (i == maxLink)
fs_put_block(sb, file->links[i]);
file->links[i] = 0; //marcando que nao tem mais bloco neste link.
i++;
if (i == maxLink && file->next != 0) {
seek_read(sb, file->next, file);
fs_put_block(sb, file->meta); //apagando bloco anterior depois de ir pro próximo.
i = 0;
}
}
//removendo na pasta tambem;
ultimo = (folder->links[getLinksLen(folder) - 1] == fileBlock);
if (ultimo) {
folder->links[getLinksLen(folder) - 1] = 0;
//folderInfo->size--;
} else {
i = 0;
while ((folder->links[i % maxLink] != fileBlock) && i < folderInfo->size) {
i++;
if ((i % maxLink == 0) && (folder->next != 0)) {
fileLinkBlk = folder->next; //guardando bloco que pode conter link pro arquivo. Saindo do while sera ele.
seek_read(sb, folder->next, folder);
}
}
lastBlock = getNodeLastLinkBlock(sb, folderBlock);
if (lastBlock == fileLinkBlk) {
folder->links[i % maxLink] = folder->links[getLinksLen(folder) - 1];
folder->links[getLinksLen(folder) - 1] = 0;
} else {
seek_read(sb, lastBlock, aux);
folder->links[i % maxLink] = aux->links[getLinksLen(aux) - 1]; //copiando ultimo link pra posicao q indicava bloco do arquivo removido
aux->links[getLinksLen(aux) - 1] = 0;
seek_write(sb, lastBlock, aux); //Devo escrever o bloco alterado de volta no disco, certo?
}
}
folderInfo->size--;
seek_write(sb, fileLinkBlk, folder); //escrevendo o que contem o link pro arquivo (foi alterado ali em cima)
seek_read(sb, folderBlock, folder); //voltando pro inode principal da pasta
seek_write(sb, folder->meta, folderInfo); //pra escrever o folderinfo no bloco onde ele estava.
free(file);
free(folder);
free(folderInfo);
free(aux);
return 0;
}
int fs_write_file(struct superblock *sb, const char *fname, char *buf, size_t cnt) {
const uint64_t blocksNeeded = MAX(1, cnt / sb->blksz);
if (blocksNeeded > sb->freeblks) {
errno = ENOSPC;
return -1;
}
int blocksUsed = 0;
if (strlen(fname) + 1 > getFileNameMaxLen(sb)) {
errno = ENAMETOOLONG;
return -1;
}
if (existsFile(sb, fname)) {
errno = EEXIST;
return -1;
}
int len = 0, exists = 0;
char** fileParts = getFileParts(fname, &len);
uint64_t dirBlock = findFile(sb, fname, &exists);
char* dirName = NULL;
struct inode* dirNode, *node;
struct nodeinfo* meta = (struct nodeinfo*) calloc(1, sb->blksz);
initNode(&dirNode, sb->blksz);
initNode(&node, sb->blksz);
seek_read(sb, dirBlock, dirNode);
seek_read(sb, dirNode->meta, meta);
dirName = calloc(1, sizeof (char)* (strlen(meta->name) + 1));
strcpy(dirName, meta->name);
if (strcmp(fileParts[MAX(0, len - 2)], dirName) != 0) {
errno = EBADF;
free(dirName);
free(node);
free(meta);
free(dirNode);
return -1;
}
uint64_t fileBlock = fs_get_block(sb);
insertInBlock(sb, dirBlock, fileBlock);
uint64_t blocksList[blocksNeeded];
///properly write the file
while (blocksUsed < blocksNeeded) {
uint64_t block = fs_get_block(sb);
blocksList[blocksUsed] = block;
char* temp = calloc(1, sb->blksz);
char* blockContent = buf + sb->blksz * (blocksUsed);
strcpy(temp, blockContent);
blocksUsed++;
seek_write(sb, block, temp);
free(temp);
}
strcpy(meta->name, fileParts[len - 1]);
meta->size = cnt;
meta->reserved[0] = 0;
node->meta = fs_get_block(sb);
node->mode = IMREG;
node->parent = dirBlock;
seek_write(sb, node->meta, meta);
uint64_t nodeBlock = fileBlock;
blocksUsed = 0;
while (blocksUsed < blocksNeeded) {
int i = 0;
int linksLen = getLinksMaxLen(sb);
int N = MIN(linksLen, blocksNeeded);
while (i < N) {
node->links[i] = blocksList[i];
i++;
blocksUsed++;
}
if (blocksUsed < blocksNeeded) {
node->next = fs_get_block(sb);
seek_write(sb, nodeBlock, node);
nodeBlock = node->next;
node->next = 0;
node->parent = fileBlock;
node->mode = IMCHILD | IMREG;
node->meta = fs_get_block(sb);
strcpy(meta->name, fileParts[len - 1]);
meta->size = cnt;
seek_write(sb, node->meta, meta);
}
}
seek_write(sb, nodeBlock, node);
free(meta);
free(node);
freeFileParts(&fileParts, len);
free(dirNode);
free(dirName);
return 0;
}