fsck1.c

操作系统源代码

/* Hacks for version 1.6 */					

#define INODES_PER_BLOCK V1_INODES_PER_BLOCK
#define INODE_SIZE V1_INODE_SIZE
#define WORDS_PER_BLOCK (BLOCK_SIZE / (int) sizeof(bitchunk_t))
#define MAX_ZONES (V1_NR_DZONES+V1_INDIRECTS+(long)V1_INDIRECTS*V1_INDIRECTS)
#define NR_DZONE_NUM V1_NR_DZONES
#define NR_INDIRECTS V1_INDIRECTS
#define NR_ZONE_NUMS V1_NR_TZONES
#define ZONE_NUM_SIZE V1_ZONE_NUM_SIZE
#define bit_nr u16_t	/* perhaps bit_t should be used, although slower */
#define Bit_nr U16_t
#define block_nr block_t
#define d_inode d1_inode
#define d_inum d_ino
#define dir_struct struct direct
#define i_mode d1_mode
#define i_nlinks d1_nlinks
#define i_size d1_size
#define i_zone d1_zone
#define zone_nr zone1_t
#define Zone_nr Zone1_t

/* fsck - file system checker		Author: Robbert van Renesse */

/* Modified by Norbert Schlenker
*   Removed vestiges of standalone/DOS versions:
*     - various unused variables and buffers removed
*     - now uses library functions rather than private internal routines
*     - bytewise structure copies replaced by structure assignment
*     - fixed one bug with 14 character file names
*     - other small tweaks for speed
*
* Modified by Lars Fredriksen at the request of Andy Tanenbaum, 90-03-10.
*   Removed -m option, by which fsck could be told to make a file
*   system on a 360K floppy.  The code had limited utility, was buggy,
*   and failed due to a bug in the ACK C compiler.  Use mkfs instead!
*/

#include <sys/types.h>
#include <sys/dir.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/type.h>
#include "../../fs/const.h"
#include "../../fs/inode.h"
#include "../../fs/type.h"
#include <minix/fslib.h>

#undef printf			/* defined as printk in "../fs/const.h" */

#include <stdio.h>

#define BITSHIFT	  4	/* = log2(#bits(int)) */

#define MAXPRINT	  8	/* max. number of error lines in chkmap */
#define MAXDIRSIZE     5000	/* max. size of a reasonable directory */
#define CINDIR		128	/* number of indirect zno's read at a time */
#define CDIRECT		 16	/* number of dir entries read at a time */
#define BITMASK		((1 << BITSHIFT) - 1)
#define setbit(w, b)	(w[(b) >> BITSHIFT] |= 1 << ((b) & BITMASK))
#define clrbit(w, b)	(w[(b) >> BITSHIFT] &= ~(1 << ((b) & BITMASK)))
#define bitset(w, b)	(w[(b) >> BITSHIFT] & (1 << ((b) & BITMASK)))

#define ZONE_CT 	360	/* default zones  (when making file system) */
#define INODE_CT	 95	/* default inodes (when making file system) */

#include "../../fs/super.h"
struct super_block sb;

#define STICKY_BIT	01000	/* not defined anywhere else */

/* Ztob gives the block address of a zone
 * btoa gives the byte address of a block
 */
#define ztob(z)		((block_nr) (z) << sb.s_log_zone_size)
#define btoa(b)		((long) (b) * BLOCK_SIZE)
#define SCALE		((int) ztob(1))	/* # blocks in a zone */
#define FIRST		((zone_nr) sb.s_firstdatazone)	/* as the name says */

/* # blocks of each type */
#define N_SUPER		1
#define N_IMAP		(sb.s_imap_blocks)
#define N_ZMAP		(sb.s_zmap_blocks)
#define N_ILIST		((sb.s_ninodes+INODES_PER_BLOCK-1) / INODES_PER_BLOCK)
#define N_DATA		(sb.s_nzones - FIRST)

/* Block address of each type */
#define BLK_SUPER	(SUPER_BLOCK)
#define BLK_IMAP	(BLK_SUPER + N_SUPER)
#define BLK_ZMAP	(BLK_IMAP  + N_IMAP)
#define BLK_ILIST	(BLK_ZMAP  + N_ZMAP)
#define BLK_FIRST	ztob(FIRST)
#define ZONE_SIZE	((int) ztob(BLOCK_SIZE))
#define NLEVEL		(NR_ZONE_NUMS - NR_DZONE_NUM + 1)

/* Byte address of a zone/of an inode */
#define zaddr(z)	btoa(ztob(z))
#define inoaddr(i)	((long) (i - 1) * INODE_SIZE + btoa(BLK_ILIST))
#define INDCHUNK	(CINDIR * ZONE_NUM_SIZE)
#define DIRCHUNK	(CDIRECT * DIR_ENTRY_SIZE)

char *prog, *device;		/* program name (fsck), device name */
int firstcnterr;		/* is this the first inode ref cnt error? */
bitchunk_t *imap, *spec_imap;	/* inode bit maps */
bitchunk_t *zmap, *spec_zmap;	/* zone bit maps */
bitchunk_t *dirmap;		/* directory (inode) bit map */
char rwbuf[BLOCK_SIZE];		/* one block buffer cache */
block_nr thisblk;		/* block in buffer cache */
char nullbuf[BLOCK_SIZE];	/* null buffer */
nlink_t *count;			/* inode count */
int changed;			/* has the diskette been written to? */
struct stack {
  dir_struct *st_dir;
  struct stack *st_next;
  char st_presence;
} *ftop;

int dev;			/* file descriptor of the device */

#define DOT	1
#define DOTDOT	2

/* Counters for each type of inode/zone. */
int nfreeinode, nregular, ndirectory, nblkspec, ncharspec, nbadinode;
int npipe, nsyml, nfreezone, ztype[NLEVEL];

int repair, automatic, listing, listsuper;	/* flags */
int firstlist;			/* has the listing header been printed? */
unsigned part_offset;		/* sector offset for this partition */
char answer[] = "Answer questions with y or n.  Then hit RETURN";

_PROTOTYPE(int main, (int argc, char **argv));
_PROTOTYPE(void initvars, (void));
_PROTOTYPE(void fatal, (char *s));
_PROTOTYPE(int eoln, (int c));
_PROTOTYPE(int yes, (char *question));
_PROTOTYPE(int atoo, (char *s));
_PROTOTYPE(int input, (char *buf, int size));
_PROTOTYPE(char *alloc, (unsigned nelem, unsigned elsize));
_PROTOTYPE(void printname, (char *s));
_PROTOTYPE(void printrec, (struct stack *sp));
_PROTOTYPE(void printpath, (int mode, int nlcr));
_PROTOTYPE(void devopen, (void));
_PROTOTYPE(void devclose, (void));
_PROTOTYPE(void devio, (block_nr bno, int dir));
_PROTOTYPE(void devread, (long offset, char *buf, int size));
_PROTOTYPE(void devwrite, (long offset, char *buf, int size));
_PROTOTYPE(void pr, (char *fmt, int cnt, char *s, char *p));
_PROTOTYPE(bit_nr getnumber, (char *s));
_PROTOTYPE(char **getlist, (char ***argv, char *type));
_PROTOTYPE(void lsuper, (void));
_PROTOTYPE(void getsuper, (void));
_PROTOTYPE(void chksuper, (void));
_PROTOTYPE(void lsi, (char **clist));
_PROTOTYPE(bitchunk_t *allocbitmap, (int nblk));
_PROTOTYPE(void loadbitmap, (bitchunk_t *bitmap, block_nr bno, int nblk));
_PROTOTYPE(void dumpbitmap, (bitchunk_t *bitmap, block_nr bno, int nblk));
_PROTOTYPE(void fillbitmap, (bitchunk_t *bitmap, Bit_nr lwb, Bit_nr upb, char **list));
_PROTOTYPE(void freebitmap, (bitchunk_t *p));
_PROTOTYPE(void getbitmaps, (void));
_PROTOTYPE(void putbitmaps, (void));
_PROTOTYPE(void chkword, (unsigned w1, unsigned w2, Bit_nr bit, char *type, int *n, int *report));
_PROTOTYPE(void chkmap, (bitchunk_t *cmap, bitchunk_t *dmap, Bit_nr bit, block_nr blkno, int nblk, char *type));
_PROTOTYPE(void chkilist, (void));
_PROTOTYPE(void getcount, (void));
_PROTOTYPE(void counterror, (Ino_t ino));
_PROTOTYPE(void chkcount, (void));
_PROTOTYPE(void freecount, (void));
_PROTOTYPE(void printperm, (Mode_t mode, int shift, int special, int overlay));
_PROTOTYPE(void list, (Ino_t ino, d_inode *ip));
_PROTOTYPE(int Remove, (dir_struct *dp));
_PROTOTYPE(void make_printable_name, (char *dst, char *src, int n));
_PROTOTYPE(int chkdots, (Ino_t ino, off_t pos, dir_struct *dp, Ino_t exp));
_PROTOTYPE(int chkname, (Ino_t ino, dir_struct *dp));
_PROTOTYPE(int chkentry, (Ino_t ino, off_t pos, dir_struct *dp));
_PROTOTYPE(int chkdirzone, (Ino_t ino, d_inode *ip, off_t pos, Zone_nr zno));
_PROTOTYPE(void errzone, (char *mess, Zone_nr zno, int level, off_t pos));
_PROTOTYPE(int markzone, (Ino_t ino, Zone_nr zno, int level, off_t pos));
_PROTOTYPE(int chkindzone, (Ino_t ino, d_inode *ip, off_t *pos, Zone_nr zno, int level));
_PROTOTYPE(off_t jump, (int level));
_PROTOTYPE(int zonechk, (Ino_t ino, d_inode *ip, off_t *pos, Zone_nr zno, int level));
_PROTOTYPE(int chkzones, (Ino_t ino, d_inode *ip, off_t *pos, zone_nr *zlist, int len, int level));
_PROTOTYPE(int chkfile, (Ino_t ino, d_inode *ip));
_PROTOTYPE(int chkdirectory, (Ino_t ino, d_inode *ip));
_PROTOTYPE(int chklink, (Ino_t ino, d_inode *ip));
_PROTOTYPE(int chkmode, (Ino_t ino, d_inode *ip));
_PROTOTYPE(int chkinode, (Ino_t ino, d_inode *ip));
_PROTOTYPE(int chkspecial, (Ino_t ino, d_inode *ip) );
_PROTOTYPE(int descendtree, (dir_struct *dp));
_PROTOTYPE(void chktree, (void));
_PROTOTYPE(void printtotal, (void));
_PROTOTYPE(void chkdev, (char *f, char **clist, char **ilist, char **zlist));

/* Initialize the variables used by this program. */
void initvars()
{
  register level;

  nregular = ndirectory = nblkspec = ncharspec = nbadinode = npipe = nsyml = 0;
  for (level = 0; level < NLEVEL; level++) ztype[level] = 0;
  changed = 0;
  thisblk = NO_BLOCK;
  firstlist = 1;
  firstcnterr = 1;
}

/* Print the string `s' and exit. */
void fatal(s)
char *s;
{
  printf("%s\nfatal\n", s);
  exit(-1);
}

/* Test for end of line. */
int eoln(c)
int c;
{
  return(c == EOF || c == '\n' || c == '\r');
}

/* Ask a question and get the answer unless automatic is set. */
int yes(question)
char *question;
{
  register c, answer;

  if (!repair) {
	printf("\n");
	return(0);
  }
  printf("%s? ", question);
  if (automatic) {
	printf("yes\n");
	return(1);
  }
  fflush(stdout);
  if ((c = answer = getchar()) == 'q' || c == 'Q') exit(1);
  while (!eoln(c)) c = getchar();
  return !(answer == 'n' || answer == 'N');
}

/* Convert string to integer.  Representation is octal. */
int atoo(s)
register char *s;
{
  register int n = 0;

  while ('0' <= *s && *s < '8') {
	n <<= 3;
	n += *s++ - '0';
  }
  return n;
}

/* If repairing the file system, print a prompt and get a string from user. */
int input(buf, size)
char *buf;
int size;
{
  register char *p = buf;

  printf("\n");
  if (repair) {
	printf("--> ");
	fflush(stdout);
	while (--size) {
		*p = getchar();
		if (eoln(*p)) {
			*p = 0;
			return(p > buf);
		}
		p++;
	}
	*p = 0;
	while (!eoln(getchar()));
	return(1);
  }
  return(0);
}

/* Allocate some memory and zero it. */
char *alloc(nelem, elsize)
unsigned nelem, elsize;
{
  char *p;

  if ((p = (char *) malloc((size_t)nelem * elsize)) == 0) fatal("out of memory");
  memset(p, 0, (size_t)nelem * elsize);
  return(p);
}

/* Print the name in a directory entry. */
void printname(s)
char *s;
{
  register n = NAME_MAX;
  int c;

  do {
	if ((c = *s) == 0) break;
	if (!isprint(c)) c = '?';
	putchar(c);
	s++;
  } while (--n);
}

/* Print the pathname given by a linked list pointed to by `sp'.  The
 * names are in reverse order.
 */
void printrec(sp)
struct stack *sp;
{
  if (sp->st_next != 0) {
	printrec(sp->st_next);
	putchar('/');
	printname(sp->st_dir->d_name);
  }
}

/* Print the current pathname.  */
void printpath(mode, nlcr)
int mode;
int nlcr;
{
  if (ftop->st_next == 0)
	putchar('/');
  else
	printrec(ftop);
  switch (mode) {
      case 1:
	printf(" (ino = %u, ", ftop->st_dir->d_inum);
	break;
      case 2:
	printf(" (ino = %u)", ftop->st_dir->d_inum);
	break;
  }
  if (nlcr) printf("\n");
}

/* Open the device.  */
void devopen()
{
  if ((dev = open(device, repair ? O_RDWR : O_RDONLY)) < 0) {
	perror(device);
	fatal("");
  }
}

/* Close the device. */
void devclose()
{
  if (close(dev) != 0) {
	perror("close");
	fatal("");
  }
}

/* Read or write a block. */
void devio(bno, dir)
block_nr bno;
int dir;
{
  if (dir == READING && bno == thisblk) return;
  thisblk = bno;

  lseek(dev, (off_t) btoa(bno), SEEK_SET);
  if (dir == READING) {
	if (read(dev, rwbuf, BLOCK_SIZE) == BLOCK_SIZE)
		return;
  } else {
	if (write(dev, rwbuf, BLOCK_SIZE) == BLOCK_SIZE)
		return;
  }

  printf("%s: can't %s block %ld (error = 0x%x)\n", prog,
         dir == READING ? "read" : "write", (long) bno, errno);
  if (dir == READING) {
	printf("Continuing with a zero-filled block.\n");
	memset(rwbuf, 0, BLOCK_SIZE);
	return;
  }
  fatal("");
}

/* Read `size' bytes from the disk starting at byte `offset'. */
void devread(offset, buf, size)
long offset;
char *buf;
int size;
{
  devio((block_nr) (offset / BLOCK_SIZE), READING);
  memmove(buf, &rwbuf[(int) (offset % BLOCK_SIZE)], (size_t)size);
}

/* Write `size' bytes to the disk starting at byte `offset'. */
void devwrite(offset, buf, size)
long offset;
char *buf;
int size;
{
  if (!repair) fatal("internal error (devwrite)");
  if (size != BLOCK_SIZE) devio((block_nr) (offset / BLOCK_SIZE), READING);
  memmove(&rwbuf[(int) (offset % BLOCK_SIZE)], buf, (size_t)size);
  devio((block_nr) (offset / BLOCK_SIZE), WRITING);
  changed = 1;
}

/* Print a string with either a singular or a plural pronoun. */
void pr(fmt, cnt, s, p)
char *fmt, *s, *p;
int cnt;
{
  printf(fmt, cnt, cnt == 1 ? s : p);
}

/* Convert string to number. */
bit_nr getnumber(s)
register char *s;
{
  register bit_nr n = 0;

  if (s == NULL)
	return NO_BIT;
  while (isdigit(*s))
	n = (n << 1) + (n << 3) + *s++ - '0';
  return (*s == '\0') ? n : NO_BIT;
}

/* See if the list pointed to by `argv' contains numbers. */
char **getlist(argv, type)
char ***argv, *type;
{
  register char **list = *argv;
  register empty = 1;

  while (getnumber(**argv) != NO_BIT) {
	(*argv)++;
	empty = 0;
  }
  if (empty) {
	printf("warning: no %s numbers given\n", type);
	return(NULL);
  }
  return(list);
}

/* Make a listing of the super block.  If `repair' is set, ask the user
 * for changes.
 */
void lsuper()
{
  char buf[80];

  do {
	printf("ninodes       = %u", sb.s_ninodes);
	if (input(buf, 80)) sb.s_ninodes = atol(buf);
	printf("nzones        = %u", sb.s_nzones);
	if (input(buf, 80)) sb.s_nzones = atol(buf);
	printf("imap_blocks   = %u", sb.s_imap_blocks);
	if (input(buf, 80)) sb.s_imap_blocks = atol(buf);
	printf("zmap_blocks   = %u", sb.s_zmap_blocks);
	if (input(buf, 80)) sb.s_zmap_blocks = atol(buf);
	printf("firstdatazone = %u", sb.s_firstdatazone);
	if (input(buf, 80)) sb.s_firstdatazone = atol(buf);
	printf("log_zone_size = %u", sb.s_log_zone_size);
	if (input(buf, 80)) sb.s_log_zone_size = atol(buf);
	printf("maxsize       = %lu", sb.s_max_size);
	if (input(buf, 80)) sb.s_max_size = atol(buf);
	if (yes("ok now")) {
		devwrite(btoa(BLK_SUPER), (char *) &sb, sizeof(sb));
		return;
	}
  } while (yes("Do you want to try again"));
  if (repair) exit(0);
}

/* Get the super block from either disk or user.  Do some initial checks. */
void getsuper()
{
  devread(btoa(BLK_SUPER), (char *) &sb, sizeof(sb));
  if (listsuper) lsuper();
  if (sb.s_magic == SUPER_V2) fatal("Cannot handle V2 file systems");
  if (sb.s_magic != SUPER_MAGIC) fatal("bad magic number in super block");
  if ((short) sb.s_ninodes <= 0) fatal("no inodes");
  if (sb.s_nzones <= 2) fatal("no zones");
  if ((short) sb.s_imap_blocks <= 0) fatal("no imap");
  if ((short) sb.s_zmap_blocks <= 0) fatal("no zmap");