structure.h~

模拟linux的ext3文件系统。采用位图法。用一个文件模拟硬盘。实现创建、删除目录、文件。读、写文件

#include <stdio.h>
#include <string.h>
#define BLOCK_BITMAP 512
#define INODE_BITMAP 2*512
#define INODE_TABLE  3*512
#define DATA_BLOCK (512*514)
#define MAX_LENGTH 512
#define ROOT_INO  1
#define DIR_ENTRIES_PER_BLOCK 16
#define MAX_OPEN_FILE 16
#define EXT2_NAME_LEN 25
/***************************************************/
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
FILE *FS;
/*************************************************/
struct ext2_group_desc{
       u8         bg_volume_name[16];
       u16        bg_block_bitmap;
       u16        bg_inode_bitmap;
       u16        bg_inode_table;
       u16        bg_free_blocks_count;
       u16        bg_free_inodes_count;
       u16        bg_used_dirs_count;
       u8         bg_pad[4];
};
struct ext2_inode{  //64 bypes
       u16        i_mode;
       u16        i_blocks;
       u32        i_size;
       u32        i_atime;
       u32        i_ctime;
       u32        i_mtime;
       u32        i_dtime;
       u16        i_block[8];
       u8         i_pad[24];
};
struct ext2_dir_entry{
       u16           d_inode;
       u16           d_length;
       u8            d_name_len;
       u8            d_file_type;
       u8 	     name[EXT2_NAME_LEN+1];
};
struct user{
	u8 username[10];
	u8 passwd[10];
};
/*********************************************************/
#ifdef MAIN
u16 file_open_table[MAX_OPEN_FILE];
u16 last_alloc_inode;
u16 last_alloc_block;
u16 current_dir;
u8 current_path[256];
struct ext2_group_desc group_desc;
#endif
/*******************************************************/
int init_FS();
int init_memory();

int update_group_desc(struct ext2_group_desc *);
int reload_group_desc(struct ext2_group_desc *);
int load_inode_entry(struct ext2_inode * ,u16);
int update_inode_entry(struct ext2_inode *, u16);
int load_block_entry(u8 *,u16);
int update_block_entry(u8 *,u16);
void free_ind(u16);
void free_dind(u16);
void free_blocks(struct ext2_inode *);
void free_inode(u16);
void free_block(u16);
u16 test_inode(u16);
u16 test_block(u16);
int match(u16,u8 *,u8 *);
void dir();
u16 mkdir(u8*,u8*);
u16 rmdir(u8 *,u8*);

int pow(int,int);
u16 new_inode();
u16 new_block();
u16 cd(u8 *);
u16 create(u8 *,u8 *);
u16 delete(u8 *,u8 *);
void close(u16 *);
u16 * open(u8 *,u8 *);
u16 write(u16 *,u8 *,u8 *);
u16 read(u16 *);
u16 get_dir(u8 *);
u16 search_name(struct ext2_inode *,u8 *,u16 *);
u16 init_dir(struct ext2_inode *,u16,u16);
u16 create_dir_entry(struct ext2_inode *,u8 *);
u16 empty_dir(struct ext2_inode *);
void print(struct ext2_inode *);
void store(struct ext2_inode *,u8 *,u16 *,u16 *);