mkfs.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <assert.h>
#include "types.h"
#include "fs.h"

int nblocks = 995;
int ninodes = 200;
int size = 1024;

int fsfd;
struct superblock sb;
char zeroes[512];
uint freeblock;
uint usedblocks;
uint bitblocks;
uint freeinode = 1;

void balloc(int);
void wsect(uint, void*);
void winode(uint, struct dinode*);
void rinode(uint inum, struct dinode *ip);
void rsect(uint sec, void *buf);
uint ialloc(ushort type);
void iappend(uint inum, void *p, int n);

// convert to intel byte order
ushort
xshort(ushort x)
{
  ushort y;
  uchar *a = (uchar*) &y;
  a[0] = x;
  a[1] = x >> 8;
  return y;
}

uint
xint(uint x)
{
  uint y;
  uchar *a = (uchar*) &y;
  a[0] = x;
  a[1] = x >> 8;
  a[2] = x >> 16;
  a[3] = x >> 24;
  return y;
}

int
main(int argc, char *argv[])
{
  int i, cc, fd;
  uint rootino, inum, off;
  struct dirent de;
  char buf[512];
  struct dinode din;

  if(argc < 2){
    fprintf(stderr, "Usage: mkfs fs.img files...\n");
    exit(1);
  }

  assert((512 % sizeof(struct dinode)) == 0);
  assert((512 % sizeof(struct dirent)) == 0);

  fsfd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666);