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

static struct dinode block_buf[BLOCKSIZ/DINODESIZ];
struct inode *ialloc()   /*  ialloc  */
{
	struct inode *temp_inode;
	unsigned int cur_di;
	int i,count,block_end_flag;
	
	if(filsys.s_pinode==NICINOD)    /*  s_inode empty  */
	{
		i=0;
		count=0;
		block_end_flag=1;
		filsys.s_pinode=NICINOD-1;
		cur_di=filsys.s_rinode;
		while((count<NICINOD) || (count<=filsys.s_ninode))
		{
			if(block_end_flag)
			{
				fseek(fd,DINODESTART+cur_di*DINODESIZ,SEEK_SET);
				fread(block_buf,1,BLOCKSIZ,fd);
				block_end_flag=0;
				i=0;
			}  
			while(block_buf[i].di_mode==DIEMPTY)
			{
				cur_di++;
				i++;
			}
			if(i==NICINOD)
				block_end_flag=1;
			else
			{
				filsys.s_inode[filsys.s_pinode--]=cur_di;
				count++;
			}
		}
		filsys.s_rinode=cur_di;
	}
	temp_inode=iget(filsys.s_inode[filsys.s_pinode]);
	fseek(fd, DINODESTART+filsys.s_inode[filsys.s_pinode]*DINODESIZ, SEEK_SET);
	fwrite(&temp_inode->di_number,1,sizeof(struct dinode),fd);
	filsys.s_pinode++;
	filsys.s_ninode--;
	filsys.s_fmod=SUPDATE;
	return temp_inode;
}

ifree(unsigned dinodeid)    /*  ifree  */
{
	filsys.s_ninode++;
	if(filsys.s_pinode!=NICINOD)    /* not full  */
	{
		filsys.s_inode[filsys.s_pinode]=dinodeid;
		filsys.s_pinode++;
	}
	else  /*full */
	{
		if(dinodeid<filsys.s_rinode)
		{
			filsys.s_inode[NICINOD]=dinodeid;
			filsys.s_rinode=dinodeid;
		}
	}
}