fsck.c

操作系统源代码

  count[dp->d_inum]++;
  if (strcmp(dp->d_name, ".") == 0) {
	ftop->st_presence |= DOT;
	return(chkdots(ino, pos, dp, ino));
  }
  if (strcmp(dp->d_name, "..") == 0) {
	ftop->st_presence |= DOTDOT;
	return(chkdots(ino, pos, dp, ino == ROOT_INODE ? ino :
			ftop->st_next->st_dir->d_inum));
  }
  if (!chkname(ino, dp)) return(0);
  if (bitset(dirmap, (bit_nr) dp->d_inum)) {
	printf("link to directory discovered in ");
	printpath(1, 0);
	printf("name = '");
	printname(dp->d_name);
	printf("', dir ino = %u)", dp->d_inum);
	return !Remove(dp);
  }
  return(descendtree(dp));
}

/* Check a zone of a directory by checking all the entries in the zone.
 * The zone is split up into chunks to not allocate too much stack.
 */
int chkdirzone(ino, ip, pos, zno)
ino_t ino;
d_inode *ip;
off_t pos;
zone_nr zno;
{
  dir_struct dirblk[CDIRECT];
  register dir_struct *dp;
  register n = SCALE * (NR_DIR_ENTRIES / CDIRECT), dirty;
  register long offset = zaddr(zno);
  register off_t size = 0;

  do {
	devread(offset, (char *) dirblk, DIRCHUNK);
	dirty = 0;
	for (dp = dirblk; dp < &dirblk[CDIRECT]; dp++) {
		if (dp->d_inum != NO_ENTRY && !chkentry(ino, pos, dp))
			dirty = 1;
		pos += DIR_ENTRY_SIZE;
		if (dp->d_inum != NO_ENTRY) size = pos;
	}
	if (dirty) devwrite(offset, (char *) dirblk, DIRCHUNK);
	offset += DIRCHUNK;
  } while (--n);

  if (size > ip->i_size) {
	printf("size not updated of directory ");
	printpath(2, 0);
	if (yes(". extend")) {
		setbit(spec_imap, (bit_nr) ino);
		ip->i_size = size;
		devwrite(inoaddr(ino), (char *) ip, INODE_SIZE);
	}
  }
  return(1);
}

/* There is something wrong with the given zone.  Print some details. */
void errzone(mess, zno, level, pos)
char *mess;
zone_nr zno;
int level;
off_t pos;
{
  printf("%s zone in ", mess);
  printpath(1, 0);
  printf("zno = %ld, type = ", zno);
  switch (level) {
      case 0:	printf("DATA");	break;
      case 1:	printf("SINGLE INDIRECT");	break;
      case 2:	printf("DOUBLE INDIRECT");	break;
      default:	printf("VERY INDIRECT");
  }
  printf(", pos = %ld)\n", pos);
}

/* Found the given zone in the given inode.  Check it, and if ok, mark it
 * in the zone bitmap.
 */
int markzone(zno, level, pos)
zone_nr zno;
int level;
off_t pos;
{
  register bit_nr bit = (bit_nr) zno - FIRST + 1;

  ztype[level]++;
  if (zno < FIRST || zno >= sb.s_zones) {
	errzone("out-of-range", zno, level, pos);
	return(0);
  }
  if (bitset(zmap, bit)) {
	setbit(spec_zmap, bit);
	errzone("duplicate", zno, level, pos);
	return(0);
  }
  nfreezone--;
  if (bitset(spec_zmap, bit)) errzone("found", zno, level, pos);
  setbit(zmap, bit);
  return(1);
}

/* Check an indirect zone by checking all of its entries.
 * The zone is split up into chunks to not allocate too much stack.
 */
int chkindzone(ino, ip, pos, zno, level)
ino_t ino;
d_inode *ip;
off_t *pos;
zone_nr zno;
int level;
{
  zone_nr indirect[CINDIR];
  register n = NR_INDIRECTS / CINDIR;
  register long offset = zaddr(zno);

  do {
	devread(offset, (char *) indirect, INDCHUNK);
	if (!chkzones(ino, ip, pos, indirect, CINDIR, level - 1)) return(0);
	offset += INDCHUNK;
  } while (--n && *pos < ip->i_size);
  return(1);
}

/* Return the size of a gap in the file, represented by a null zone number
 * at some level of indirection.
 */
off_t jump(level)
int level;
{
  off_t power = ZONE_SIZE;

  if (level != 0) do
		power *= NR_INDIRECTS;
	while (--level);
  return(power);
}

/* Check a zone, which may be either a normal data zone, a directory zone,
 * or an indirect zone.
 */
int zonechk(ino, ip, pos, zno, level)
ino_t ino;
d_inode *ip;
off_t *pos;
zone_nr zno;
int level;
{
  if (level == 0) {
	if ((ip->i_mode & I_TYPE) == I_DIRECTORY &&
	    !chkdirzone(ino, ip, *pos, zno))
		return(0);
	*pos += ZONE_SIZE;
	return(1);
  } else
	return chkindzone(ino, ip, pos, zno, level);
}

/* Check a list of zones given by `zlist'. */
int chkzones(ino, ip, pos, zlist, len, level)
ino_t ino;
d_inode *ip;
off_t *pos;
zone_nr *zlist;
int len;
int level;
{
  register ok = 1, i;

  /* The check on the position in the next loop is commented out, since FS
   * now requires valid zone numbers in each level that is necessary and FS
   * always deleted all the zones in the double indirect block.
   */
  for (i = 0; i < len /* && *pos < ip->i_size */ ; i++)
	if (zlist[i] == NO_ZONE)
		*pos += jump(level);
	else if (!markzone(zlist[i], level, *pos)) {
		*pos += jump(level);
		ok = 0;
	} else if (!zonechk(ino, ip, pos, zlist[i], level))
		ok = 0;
  return(ok);
}

/* Check a file or a directory. */
int chkfile(ino, ip)
ino_t ino;
d_inode *ip;
{
  register ok, i, level;
  off_t pos = 0;

  ok = chkzones(ino, ip, &pos, &ip->i_zone[0], NR_DZONE_NUM, 0);
  for (i = NR_DZONE_NUM, level = 1; i < NR_ZONE_NUMS; i++, level++)
	ok &= chkzones(ino, ip, &pos, &ip->i_zone[i], 1, level);
  return(ok);
}

/* Check a directory by checking the contents.  Check if . and .. are present. */
int chkdirectory(ino, ip)
ino_t ino;
d_inode *ip;
{
  register ok;

  setbit(dirmap, (bit_nr) ino);
  if (ip->i_size > MAXDIRSIZE) {
	printf("warning: huge directory: ");
	printpath(2, 1);
  }
  ok = chkfile(ino, ip);
  if (!(ftop->st_presence & DOT)) {
	printf(". missing in ");
	printpath(2, 1);
	ok = 0;
  }
  if (!(ftop->st_presence & DOTDOT)) {
	printf(".. missing in ");
	printpath(2, 1);
	ok = 0;
  }
  return(ok);
}

#ifdef I_SYMBOLIC_LINK

/* Check the validity of a symbolic link. */
int chklink(ino, ip)
ino_t ino;
d_inode *ip;
{
  int ok;

  ok = chkfile(ino, ip);
  if (ip->i_size <= 0 || ip->i_size > BLOCK_SIZE) {
	if (ip->i_size == 0)
		printf("empty symbolic link ");
	else
		printf("symbolic link too large (size %ld) ", ip->i_size);
	printpath(2, 1);
	ok = 0;
  }
  return(ok);
}

#endif

/* Check the validity of a special file. */
int chkspecial(ino, ip)
ino_t ino;
d_inode *ip;
{
  int i, ok;

  ok = 1;
  if ((dev_t) ip->i_zone[0] == NO_DEV) {
	printf("illegal device number %ld for special file ", ip->i_zone[0]);
	printpath(2, 1);
	ok = 0;
  }

  /* FS will not use the remaining "zone numbers" but 1.6.11++ will panic if
   * they are nonzero, since this should not happen.
   */
  for (i = 1; i < NR_ZONE_NUMS; i++)
	if (ip->i_zone[i] != NO_ZONE) {
		printf("nonzero zone number %ld for special file ",
		       ip->i_zone[i]);
		printpath(2, 1);
		ok = 0;
	}
  return(ok);
}

/* Check the mode and contents of an inode. */
int chkmode(ino, ip)
ino_t ino;
d_inode *ip;
{
  switch (ip->i_mode & I_TYPE) {
      case I_REGULAR:
	nregular++;
	return chkfile(ino, ip);
      case I_DIRECTORY:
	ndirectory++;
	return chkdirectory(ino, ip);
      case I_BLOCK_SPECIAL:
	nblkspec++;
	return chkspecial(ino, ip);
      case I_CHAR_SPECIAL:
	ncharspec++;
	return chkspecial(ino, ip);
      case I_NAMED_PIPE:
	npipe++;
	return chkfile(ino, ip);
#ifdef I_SYMBOLIC_LINK
      case I_SYMBOLIC_LINK:
	nsyml++;
	return chklink(ino, ip);
#endif
      default:
	nbadinode++;
	printf("bad mode of ");
	printpath(1, 0);
	printf("mode = %o)", ip->i_mode);
	return(0);
  }
}

/* Check an inode. */
int chkinode(ino, ip)
ino_t ino;
d_inode *ip;
{
  if (ino == ROOT_INODE && (ip->i_mode & I_TYPE) != I_DIRECTORY) {
	printf("root inode is not a directory ");
	printf("(ino = %u, mode = %o)\n", ino, ip->i_mode);
	fatal("");
  }
  if (ip->i_nlinks == 0) {
	printf("link count zero of ");
	printpath(2, 0);
	return(0);
  }
  nfreeinode--;
  setbit(imap, (bit_nr) ino);
  if ((unsigned) ip->i_nlinks > LINK_MAX) {
	printf("link count too big in ");
	printpath(1, 0);
	printf("cnt = %u)\n", (unsigned) ip->i_nlinks);
	count[ino] -= LINK_MAX;
	setbit(spec_imap, (bit_nr) ino);
  } else {
	count[ino] -= (unsigned) ip->i_nlinks;
  }
  return chkmode(ino, ip);
}

/* Check the directory entry pointed to by dp, by checking the inode. */
int descendtree(dp)
dir_struct *dp;
{
  d_inode inode;
  register ino_t ino = dp->d_inum;
  register visited;
  struct stack stk;

  stk.st_dir = dp;
  stk.st_next = ftop;
  ftop = &stk;
  if (bitset(spec_imap, (bit_nr) ino)) {
	printf("found inode %u: ", ino);
	printpath(0, 1);
  }
  visited = bitset(imap, (bit_nr) ino);
  if (!visited || listing) {
	devread(inoaddr(ino), (char *) &inode, INODE_SIZE);
	if (listing) list(ino, &inode);
	if (!visited && !chkinode(ino, &inode)) {
		setbit(spec_imap, (bit_nr) ino);
		if (yes("remove")) {
			count[ino] += inode.i_nlinks - 1;
			clrbit(imap, (bit_nr) ino);
			devwrite(inoaddr(ino), nullbuf, INODE_SIZE);
			memset((void *) dp, 0, sizeof(dir_struct));
			ftop = ftop->st_next;
			return(0);
		}
	}
  }
  ftop = ftop->st_next;
  return(1);
}

/* Check the file system tree. */
void chktree()
{
  dir_struct dir;

  nfreeinode = sb.s_ninodes;
  nfreezone = N_DATA;
  dir.d_inum = ROOT_INODE;
  dir.d_name[0] = 0;
  if (!descendtree(&dir)) fatal("bad root inode");
  putchar('\n');
}

/* Print the totals of all the objects found. */
void printtotal()
{
  printf("blocksize = %5d        ", BLOCK_SIZE);
  printf("zonesize  = %5d\n", ZONE_SIZE);
  printf("\n");
  pr("%6u    Regular file%s\n", nregular, "", "s");
  pr("%6u    Director%s\n", ndirectory, "y", "ies");
  pr("%6u    Block special file%s\n", nblkspec, "", "s");
  pr("%6u    Character special file%s\n", ncharspec, "", "s");
  if (nbadinode != 0) pr("%6u    Bad inode%s\n", nbadinode, "", "s");
  pr("%6u    Free inode%s\n", nfreeinode, "", "s");
  pr("%6u    Named pipe%s\n", npipe, "", "s");
  pr("%6u    Symbolic link%s\n", nsyml, "", "s");
/* Don't print some fields.
  printf("\n");
  pr("%6u    Data zone%s\n",		  ztype[0],	 "",   "s");
  pr("%6u    Single indirect zone%s\n",	  ztype[1],	 "",   "s");
  pr("%6u    Double indirect zone%s\n",	  ztype[2],	 "",   "s");
*/
  lpr("%6ld    Free zone%s\n", nfreezone, "", "s");
}

/* Check the device which name is given by `f'.  The inodes listed by `clist'
 * should be listed separately, and the inodes listed by `ilist' and the zones
 * listed by `zlist' should be watched for while checking the file system.
 */

void chkdev(f, clist, ilist, zlist)
char *f, **clist, **ilist, **zlist;
{
  if (automatic) repair = 1;
  device = f;
  initvars();

  devopen();

  getsuper();
  chksuper();

  lsi(clist);

  getbitmaps();

  fillbitmap(spec_imap, (bit_nr) 1, (bit_nr) sb.s_ninodes + 1, ilist);
  fillbitmap(spec_zmap, (bit_nr) FIRST, (bit_nr) sb.s_zones, zlist);

  getcount();
  chktree();
  chkmap(zmap, spec_zmap, (bit_nr) FIRST - 1, BLK_ZMAP, N_ZMAP, "zone");
  chkcount();
  chkmap(imap, spec_imap, (bit_nr) 0, BLK_IMAP, N_IMAP, "inode");
  chkilist();
  printtotal();

  putbitmaps();
  freecount();
  devclose();

  if (changed) printf("----- FILE SYSTEM HAS BEEN MODIFIED -----\n\n");
}

int main(argc, argv)
int argc;
char **argv;
{
  register char **clist = 0, **ilist = 0, **zlist = 0;

  register devgiven = 0;
  register char *arg;

  if ((1 << BITSHIFT) != 8 * sizeof(bitchunk_t)) {
	printf("Fsck was compiled with the wrong BITSHIFT!\n");
	exit(1);
  }

  sync();
  prog = *argv++;
  while ((arg = *argv++) != 0)
	if (arg[0] == '-' && arg[1] != 0 && arg[2] == 0) switch (arg[1]) {
		    case 'a':	automatic ^= 1;	break;
		    case 'c':
			clist = getlist(&argv, "inode");
			break;
		    case 'i':
			ilist = getlist(&argv, "inode");
			break;
		    case 'z':
			zlist = getlist(&argv, "zone");
			break;
		    case 'r':	repair ^= 1;	break;
		    case 'l':	listing ^= 1;	break;
		    case 's':	listsuper ^= 1;	break;
		    default:
			printf("%s: unknown flag '%s'\n", prog, arg);
		}
	else {
		chkdev(arg, clist, ilist, zlist);
		clist = 0;
		ilist = 0;
		zlist = 0;
		devgiven = 1;
	}
  if (!devgiven) {
	printf("Usage: fsck [-acilrsz] file\n");
	exit(1);
  }
  return(0);
}