ufs.h

使用FUSE提供的API,在linux下实现的简单的文件系统。此为操作系统课程设计。

/*
* UFS: our own Filesystem in Userspace 
* Copyright (c) 2009 LuQianhui <[e-mail]>
* All rights reserved.
*
* 文件名称：ufs.h
* 摘    要：ufs的头文件，定义了文件系统的相关参数           
*
* 当前版本：1.0
* 作    者：飘零青丝
* 完成日期：2009年2月20日
*
*/

#ifndef UFS_H
#define UFS_H

#include <stddef.h>

#define DISK "/home/luqianhui/1/src/diskimg"  /* 包含文件系统信息的映射文件的路径，请使用绝对路径*/

#define MAX_BITMAP_IN_BLOCK 1280 /* 位图块的数量*/
#define MAX_FILENAME 8           /* 文件名的最大长度*/
#define MAX_EXTENSION 3         /* 文件扩展名的最大长度 */
#define MAX_DATA_IN_BLOCK 504		/* 数据块能容纳的最大数据 the size of size_t and long is 4 seperately, 504=512-4-4 */
#define BLOCK_BYTES 512         /* 每块的容量*/       



long max_filesystem_in_block; 

typedef struct {
     long fs_size;                     //size of file system, in blocks
     long first_blk;                   //first block of root directory
     long bitmap;                      //size of bitmap, in blocks
}sb;

typedef struct {
     char fname[MAX_FILENAME + 1];      //filename (plus space for nul)
     char fext[MAX_EXTENSION + 1];      //extension (plus space for nul)
     size_t fsize;                      //file size, but for directory it doesn't need it
     long nStartBlock;                  //where the first block is on disk
     int flag;                          //indicate type of file. 0:for unused; 1:for file; 2:for directory
}u_fs_file_directory;

typedef struct {
     size_t size;                      // how many bytes are being used in this block
     long nNextBlock;                  //The next disk block, if needed. This is the next pointer in the linked allocation list. else value -1
     char data[MAX_DATA_IN_BLOCK];     // And all the rest of the space in the block can be used for actual data storage
}u_fs_disk_block ;

typedef long int ufs_DIR;              //the position value of dir_entry corresponds to the number of bytes 
									   //from the beginning of the image file
							  
#endif