lab7-0572201-myfs.c

linux下用文件模拟文件系统的各种操作

	int nblock = createblock(pinode);
	if (nblock < 0) return 0;
	writeblock(nblock, buff);
	return 1;
}
void closefile(struct inode *pinode) {
	int index = exists(pinode->name);
	if (index < 0) return;
	writeinode(index, pinode);
	free(pinode);
}


void copyblocks(int root, int h, int count, FILE *fout) {
	int b = sb.s_block_size / 4;
	int i;
	char *buff = (char*)malloc(sb.s_block_size);
	readblock(root, buff);
	if (h == 0) {
		fwrite(buff, 1, count, fout);
	}
	else {
		int powerb = power(b, h - 1);
		int bound = count / sb.s_block_size / powerb;
		for (i = 0; i < bound; i++) {
			copyblocks(((int*)buff)[i], h - 1, powerb * sb.s_block_size, fout);
		}
		copyblocks(((int*)buff)[bound], h - 1, count - powerb * sb.s_block_size * bound, fout);
	}
	free(buff);
}
void removeblocks(int root, int h, int blockcount) {
	int b = sb.s_block_size / 4;
	int *intbuff;
	int i = 0;
	int powerb;
	if (h == 0) {
		releaseblock(root);
		return;
	}
	intbuff = (int*)malloc(sb.s_block_size);
	readblock(root, (char*)intbuff);
	powerb = power(b, h - 1);
	while (blockcount >= powerb) {
		removeblocks(intbuff[i], h - 1, powerb); 
		blockcount -= powerb;
		i++;
	}
	removeblocks(intbuff[i], h - 1, blockcount);
	free(intbuff);
	releaseblock(root);
}

int mycpout(char* srcfilename, char* destfilename)
{
	FILE *fout;
	struct inode in;
	int filenum;
	int blocks;
	int i;
	int b;
	char *buff = (char*)malloc(sb.s_block_size);
	int remainder;
	int index = 12;
	int h = 0;
	int powerb;
	b = sb.s_block_size / 4;
	powerb = b;
	filenum = exists(srcfilename);
	if (filenum < 0) {
		return 0;
	}
	readinode(filenum, &in);
	if (strcmp(destfilename, "stdout") == 0) {
		fout = stdout;
	}
	else {
		fout = fopen(destfilename, "wb");
	}
	if (fout == 0) return 0;
	blocks = in.i_blocks;
	remainder = in.i_size;
	if (blocks <= 12) {
		for (i = 0; i < blocks - 1; i++) {
			copyblocks(in.i_block[i], 0, sb.s_block_size, fout);
		}
		copyblocks(in.i_block[i], 0, in.i_size % sb.s_block_size, fout);
		return 1;
	}
	blocks -= 12;
	for (i = 0; i < 12; i++) {
		copyblocks(in.i_block[i], 0, sb.s_block_size, fout);
	}
	remainder -= 12 * sb.s_block_size;
	h = 1;
	powerb = b;
	while (blocks >= powerb) {
		copyblocks(in.i_block[index], h, powerb * sb.s_block_size, fout);
		index++;
		h++;
		blocks -= powerb;
		remainder -= powerb * sb.s_block_size;
		powerb *= b;
	}
	copyblocks(in.i_block[index], h, remainder, fout);
	free(buff);
	if (fout != stdout)
		fclose(fout);
	return 1;
}

int myrm(char* filename)
{
	int iinode = exists(filename);
	struct inode in;
	int i;
	int blocks;
	int b = sb.s_block_size / 4;
	int powerb = b;
	int index = 12;
	int h = 1;
	if (iinode < 0) return 0;
	readinode(iinode, &in);
	blocks = in.i_blocks;
	if (blocks <= 12) {
		for (i = 0; i < blocks; i++) releaseblock(in.i_block[i]);
		releaseinode(iinode);
		return 1;
	}
	for (i = 0; i < 12; i++) releaseblock(in.i_block[i]);
	blocks -= 12;
	h = 1;
	while (blocks >= powerb) {
		removeblocks(in.i_block[index++], h++, powerb);
		blocks -= powerb;
		powerb *=  b;
	}
	removeblocks(in.i_block[index], h, blocks);
	releaseinode(iinode);
	return 1;
}

int myls(void)
{
	int ibyte;
	int ibit;
	int iinode;
	int cur;
	struct inode in;
	char ch;
	fseek(disk, gd.bg_inode_bitmap * sb.s_block_size, 0);
	printf("filename\t\tfilesize\n");
	for (ibyte = 0; ibyte < sb.s_block_size; ibyte++) {
		ch = fgetc(disk);
		for (ibit = 0; ibit < 8; ibit++) {
			if ( (ch >> ibit) & 1) {
				iinode = ibyte * 8 + ibit;
				cur = ftell(disk);
				fseek(disk, gd.bg_inode_table * sb.s_block_size + iinode * sb.s_inode_size, 0);
				fread(&in, sb.s_inode_size, 1, disk);
				printf("%s\t\t\t%-8dB\n", in.name, in.i_size);
				fseek(disk, cur, 0);
			}
		}
	}
	return 1;
}

int mytouch(char* filename)
{
	struct inode *pinode = createfile(filename);
	int length = 0;
	int count = 0;
	char ch;
	char *buff = (char*)malloc(sb.s_block_size);
	if (pinode == 0) return 0;
	printf("Input file content below. enter '$' to end input.\n");
	while ((ch = getchar()) != '$')
	{
		buff[count] = ch;
		count++;
		if (count>=sb.s_block_size)
		{
			appendfile(pinode, buff);
			length +=  count;
			count=0;
		}
	}
	if (count > 0)
		appendfile(pinode, buff);
	length += count;
	pinode->i_size = length;
	closefile(pinode);
	return length;
}
int mycpin(char* srcfilename, char* destfilename)
{
	FILE *fin = fopen(srcfilename, "rb");
	int readcount;
	int length = 0;
	int error = 0;
	char *buff = (char*)malloc(sb.s_block_size);
	struct inode *fout = createfile(destfilename);
	if (fin == 0) return 0;
	if (fout == 0) return 0;
	do {
		readcount = fread(buff, 1, sb.s_block_size, fin);
		if (!appendfile(fout, buff)) {
			error = 1;
			break;
		}
		if (readcount < sb.s_block_size) break;
		length += readcount;
	} while (1);
	if (!error) length += readcount;
	fout->i_size = length;
	closefile(fout);
	return 1;
}
int mydisplay(char* filename)
{
	/*--open file to display in text mode--*/
	return mycpout(filename, "stdout");
}



/*----------------------------------------------------------
The following code is demo,
do NOT change!
----------------------------------------------------------------*/

int test_initfs(void);
int test_cpin(void);
int test_cpout(void);
int test_rm(void);
int test_ls(void);
int test_touch(void);
int test_display(void);

int get_filename(char*);

int main(void)
{
	int ch = 0;
	int result = 1;

	if (!mount_disk())
	{
		perror("disk file not associated");
		return -1;
	}

	while (ch!= 'q')
	{
		printf("\n\t-----------------MYFS FILE SYSTEM--------------- \n");
		printf("\t\t 0 --- Format Disk\n");
		printf("\t\t 1 --- Copy file from Linux to MYFS\n");
		printf("\t\t 2 --- Copy file from MYFS to Linux\n");
		printf("\t\t 3 --- Remove a file\n");
		printf("\t\t 4 --- List all files in MYFS\n");
		printf("\t\t 5 --- Create a new file\n");
		printf("\t\t 6 --- Display file content\n");
		printf("\t\t q --- Quit\n");
		printf("\t------------------------------------------------\nEnter Your Choice:");
		scanf(" %c", &ch);
		switch (ch)
		{

		case '0':
			result= test_initfs();
			break;
		case '1':
			getchar();
			result = test_cpin();
			break;
		case '2':
			getchar();
			result = test_cpout();
			break;
		case '3':
			getchar();
			result = test_rm();
			break;
		case '4':
			result= test_ls();
			break;
		case '5':
			getchar();
			result = test_touch();
			break;
		case '6':
			getchar();
			result = test_display();
			break;
		case '\n':
			continue;
			break;
		}
		if (!result)
			printf("\nError!!!!\n");

	}
	unmount_disk();
	return 0;

}

int test_initfs(void)
{
	unsigned int bsize, icount;
	printf("Disk sector size=%d; total space=%d Bytes\n", SECTOR_SIZE, (SECTOR_SIZE*TOTAL_SECTOR));
	printf("Please input block size: (preferred %d, %d, %d)\n",SECTOR_SIZE,(SECTOR_SIZE*2),(SECTOR_SIZE*4));
	scanf("%d",&bsize);
	printf("Please input maximal inode count (e.g. 1000) \n");
	scanf("%d",&icount);
	return myinitfs(bsize,icount);
}
int test_cpin(void)
{
	char srcfile[MYFS_NAME_LEN];
	char destfile[MYFS_NAME_LEN];
	printf("Source File in Linux, ");
	get_filename(srcfile);
	printf("Destination File in MYFS, ");
	get_filename(destfile);
	return mycpin(srcfile,destfile);
}
int test_cpout(void)
{
	char srcfile[MYFS_NAME_LEN];
	char destfile[MYFS_NAME_LEN];
	printf("Source File in MYFS, ");
	get_filename(srcfile);
	printf("Destination File in Linux, ");
	get_filename(destfile);
	return mycpout(srcfile,destfile);
}
int test_rm(void)
{
	char srcfile[MYFS_NAME_LEN];
	printf("Source File in MYFS, ");
	get_filename(srcfile);
	return myrm(srcfile);

}
int test_ls(void)
{
	return myls();
}

int test_touch(void)
{
	char fn[MYFS_NAME_LEN];
	printf("Create new file, ");
	if(get_filename(fn))
	{
		return mytouch(fn);              
	}
	else
	{
		return 0;
	}
}

int test_display(void)
{
	char fn[MYFS_NAME_LEN];
	printf("display a file, ");
	if(get_filename(fn))
	{
		return mydisplay(fn);              
	}
	else
	{
		return 0;
	}

}

int get_filename(char* filename)
{
	int len;

	printf("Enter filename:");
	fgets(filename, MYFS_NAME_LEN, stdin);
	len = strlen(filename);

	if (filename[len-1] == '\n')
	{
		filename[len-1] = '\0';
		len--;
	}
	return len;
}