access.c

设计并实现一个多用户多级目录结构的文件系统

/************************************************/
/*												*/
/*					access.c					*/
/*												*/
/************************************************/

#include <stdio.h>
#include "filsys.h"

unsigned short access( struct inode * inode )
{
	unsigned short can = 0;
	if(( inode->i_mode & ODIREAD ) ||
		(( inode->i_mode & GDIREAD ) && 
		( user[user_id].u_gid == inode->i_gid )) ||
		((inode->i_mode & UDIREAD) &&
		( user[user_id].u_uid == inode->i_uid )))
		can = can | READ;

	if(( inode->i_mode & ODIWRITE ) ||
		(( inode->i_mode & GDIWRITE ) && 
		(user[user_id].u_gid == inode->i_gid )) ||
		(( inode->i_mode & UDIWRITE) &&
		( user[user_id].u_uid == inode->i_uid )))
		can = can | WRITE;

	if(( inode->i_mode & ODIEXICUTE ) ||
		(( inode->i_mode & GDIEXICUTE ) && 
		( user[user_id].u_gid == inode->i_gid )) ||
		(( inode->i_mode & UDIEXICUTE) &&
		( user[user_id].u_uid == inode->i_uid )))
	can = can | EXICUTE;
	
	return can;
}