fsck.minix.c

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/*
 * fsck.c - a file system consistency checker for Linux.
 *
 * (C) 1991, 1992 Linus Torvalds. This file may be redistributed
 * as per the GNU copyleft.
 */

/*
 * 09.11.91  -  made the first rudimetary functions
 *
 * 10.11.91  -  updated, does checking, no repairs yet.
 *		Sent out to the mailing-list for testing.
 *
 * 14.11.91  -	Testing seems to have gone well. Added some
 *		correction-code, and changed some functions.
 *
 * 15.11.91  -  More correction code. Hopefully it notices most
 *		cases now, and tries to do something about them.
 *
 * 16.11.91  -  More corrections (thanks to Mika Jalava). Most
 *		things seem to work now. Yeah, sure.
 *
 *
 * 19.04.92  -	Had to start over again from this old version, as a
 *		kernel bug ate my enhanced fsck in february.
 *
 * 28.02.93  -	added support for different directory entry sizes..
 *
 * Sat Mar  6 18:59:42 1993, [e-mail]: Output namelen with
 *                           super-block information
 *
 * Sat Oct  9 11:17:11 1993, [e-mail]: make exit status conform
 *                           to that required by fsutil
 *
 * Mon Jan  3 11:06:52 1994 - Dr. Wettstein ([e-mail])
 *			      Added support for file system valid flag.  Also
 *			      added program_version variable and output of
 *			      program name and version number when program
 *			      is executed.
 *
 * 30.10.94 - added support for v2 filesystem
 *            (Andreas Schwab, [e-mail])
 *
 * 10.12.94  -  added test to prevent checking of mounted fs adapted
 *              from Theodore Ts'o's ([e-mail]) e2fsck
 *              program.  (Daniel Quinlan, [e-mail])
 *
 * 01.07.96  - Fixed the v2 fs stuff to use the right #defines and such
 *	       for modern libcs ([e-mail], Nicolai Langfeldt)
 *
 * 02.07.96  - Added C bit fiddling routines from [e-mail] 
 *             (Russell King).  He made them for ARM.  It would seem
 *	       that the ARM is powerful enough to do this in C whereas
 *             i386 and m64k must use assembly to get it fast >:-)
 *	       This should make minix fsck systemindependent.
 *	       ([e-mail], Nicolai Langfeldt)
 *
 * 04.11.96  - Added minor fixes from Andreas Schwab to avoid compiler
 *             warnings.  Added mc68k bitops from 
 *	       Joerg Dorchain <[e-mail]>.
 *
 * 06.11.96  - Added v2 code submitted by Joerg Dorchain, but written by
 *             Andreas Schwab.
 *
 * 1999-02-22 Arkadiusz Mi秌iewicz <[e-mail]>
 * - added Native Language Support
 *
 *
 * I've had no time to add comments - hopefully the function names
 * are comments enough. As with all file system checkers, this assumes
 * the file system is quiescent - don't use it on a mounted device
 * unless you can be sure nobody is writing to it (and remember that the
 * kernel can write to it when it searches for files).
 *
 * Usuage: fsck [-larvsm] device
 *	-l for a listing of all the filenames
 *	-a for automatic repairs (not implemented)
 *	-r for repairs (interactive) (not implemented)
 *	-v for verbose (tells how many files)
 *	-s for super-block info
 *	-m for minix-like "mode not cleared" warnings
 *	-f force filesystem check even if filesystem marked as valid
 *
 * The device may be a block device or a image of one, but this isn't
 * enforced (but it's not much fun on a character device :-). 
 */

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <ctype.h>
#include <stdlib.h>
#include <termios.h>
#include <mntent.h>
#include <sys/stat.h>

#include "minix.h"
#include "nls.h"

#ifndef __linux__
#define volatile
#endif

#define ROOT_INO 1

#define UPPER(size,n) ((size+((n)-1))/(n))
#define INODE_SIZE (sizeof(struct minix_inode))
#define INODE_SIZE2 (sizeof(struct minix2_inode))
#define INODE_BLOCKS UPPER(INODES, (version2 ? MINIX2_INODES_PER_BLOCK \
				    : MINIX_INODES_PER_BLOCK))
#define INODE_BUFFER_SIZE (INODE_BLOCKS * BLOCK_SIZE)

#define BITS_PER_BLOCK (BLOCK_SIZE<<3)

static char * program_name = "fsck.minix";
static char * device_name = NULL;
static int IN;
static int repair=0, automatic=0, verbose=0, list=0, show=0, warn_mode=0, 
	force=0;
static int directory=0, regular=0, blockdev=0, chardev=0, links=0,
		symlinks=0, total=0;

static int changed = 0; /* flags if the filesystem has been changed */
static int errors_uncorrected = 0; /* flag if some error was not corrected */
static int dirsize = 16;
static int namelen = 14;
static int version2 = 0;
static struct termios termios;
static int termios_set = 0;

/* File-name data */
#define MAX_DEPTH 50
static int name_depth = 0;
static char name_list[MAX_DEPTH][NAME_MAX+1];
/* Copy of the previous, just for error reporting - see get_current_name */
/* This is a waste of 12kB or so. */
static char current_name[MAX_DEPTH*(NAME_MAX+1)+1];

static char * inode_buffer = NULL;
#define Inode (((struct minix_inode *) inode_buffer)-1)
#define Inode2 (((struct minix2_inode *) inode_buffer)-1)
static char super_block_buffer[BLOCK_SIZE];
#define Super (*(struct minix_super_block *)super_block_buffer)
#define INODES ((unsigned long)Super.s_ninodes)
#define ZONES ((unsigned long)(version2 ? Super.s_zones : Super.s_nzones))
#define IMAPS ((unsigned long)Super.s_imap_blocks)
#define ZMAPS ((unsigned long)Super.s_zmap_blocks)
#define FIRSTZONE ((unsigned long)Super.s_firstdatazone)
#define ZONESIZE ((unsigned long)Super.s_log_zone_size)
#define MAXSIZE ((unsigned long)Super.s_max_size)
#define MAGIC (Super.s_magic)
#define NORM_FIRSTZONE (2+IMAPS+ZMAPS+INODE_BLOCKS)

static char *inode_map;
static char *zone_map;

static unsigned char * inode_count = NULL;
static unsigned char * zone_count = NULL;

static void recursive_check(unsigned int ino);
static void recursive_check2(unsigned int ino);

#include "bitops.h"

#define inode_in_use(x) (bit(inode_map,(x)))
#define zone_in_use(x) (bit(zone_map,(x)-FIRSTZONE+1))

#define mark_inode(x) (setbit(inode_map,(x)),changed=1)
#define unmark_inode(x) (clrbit(inode_map,(x)),changed=1)

#define mark_zone(x) (setbit(zone_map,(x)-FIRSTZONE+1),changed=1)
#define unmark_zone(x) (clrbit(zone_map,(x)-FIRSTZONE+1),changed=1)

static void
leave(int status) {
	if (termios_set)
		tcsetattr(0, TCSANOW, &termios);
	exit(status);
}

static void
usage(void) {
	fprintf(stderr,
		_("Usage: %s [-larvsmf] /dev/name\n"),
		program_name);
	leave(16);
}

static void
die(const char *str) {
	fprintf(stderr, "%s: %s\n", program_name, str);
	leave(8);
}

/*
 * This simply goes through the file-name data and prints out the
 * current file.
 */
static void
get_current_name(void) {
	int i = 0, ct;
	char *p, *q;

	q = current_name;
	while (i < name_depth) {
		p = name_list[i++];
		ct = namelen;
		*q++ = '/';
		while (ct-- && *p)
			*q++ = *p++;
	}
	if (i == 0)
		*q++ = '/';
	*q = 0;
}

static int
ask(const char * string, int def) {
	int c;

	if (!repair) {
		printf("\n");
		errors_uncorrected = 1;
		return 0;
	}
	if (automatic) {
		printf("\n");
		if (!def)
		      errors_uncorrected = 1;
		return def;
	}
	printf(def?"%s (y/n)? ":"%s (n/y)? ",string);
	for (;;) {
		fflush(stdout);
		if ((c=getchar())==EOF) {
		        if (!def)
			      errors_uncorrected = 1;
			return def;
		}
		c=toupper(c);
		if (c == 'Y') {
			def = 1;
			break;
		} else if (c == 'N') {
			def = 0;
			break;
		} else if (c == ' ' || c == '\n')
			break;
	}
	if (def)
		printf("y\n");
	else {
		printf("n\n");
		errors_uncorrected = 1;
	     }
	return def;
}

/*
 * Make certain that we aren't checking a filesystem that is on a
 * mounted partition.  Code adapted from e2fsck, Copyright (C) 1993,
 * 1994 Theodore Ts'o.  Also licensed under GPL.
 */
static void
check_mount(void) {
	FILE * f;
	struct mntent * mnt;
	int cont;
	int fd;

	if ((f = setmntent (MOUNTED, "r")) == NULL)
		return;
	while ((mnt = getmntent (f)) != NULL)
		if (strcmp (device_name, mnt->mnt_fsname) == 0)
			break;
	endmntent (f);
	if (!mnt)
		return;

	/*
	 * If the root is mounted read-only, then /etc/mtab is
	 * probably not correct; so we won't issue a warning based on
	 * it.
	 */
	fd = open(MOUNTED, O_RDWR);
	if (fd < 0 && errno == EROFS)
		return;
	else
		close(fd);
	
	printf (_("%s is mounted.	 "), device_name);
	if (isatty(0) && isatty(1))
		cont = ask(_("Do you really want to continue"), 0);
	else
		cont = 0;
	if (!cont) {
		printf (_("check aborted.\n"));
		exit (0);
	}
	return;
}

/*
 * check_zone_nr checks to see that *nr is a valid zone nr. If it
 * isn't, it will possibly be repaired. Check_zone_nr sets *corrected
 * if an error was corrected, and returns the zone (0 for no zone
 * or a bad zone-number).
 */
static int
check_zone_nr(unsigned short * nr, int * corrected) {
	if (!*nr)
		return 0;

	if (*nr < FIRSTZONE) {
		get_current_name();
		printf(_("Zone nr < FIRSTZONE in file `%s'."),
		       current_name);
	} else if (*nr >= ZONES) {
		get_current_name();
		printf(_("Zone nr >= ZONES in file `%s'."),
		       current_name);
	} else
		return *nr;

	if (ask(_("Remove block"),1)) {
		*nr = 0;
		*corrected = 1;
	}
	return 0;
}

static int
check_zone_nr2 (unsigned int *nr, int *corrected) {
	if (!*nr)
		return 0;

	if (*nr < FIRSTZONE) {
		get_current_name();
		printf (_("Zone nr < FIRSTZONE in file `%s'."),
			current_name);
	} else if (*nr >= ZONES) {
		get_current_name();
		printf (_("Zone nr >= ZONES in file `%s'."),
			current_name);
	} else
		return *nr;

	if (ask (_("Remove block"), 1)) {
		*nr = 0;
		*corrected = 1;
	}
	return 0;
}

/*
 * read-block reads block nr into the buffer at addr.
 */
static void
read_block(unsigned int nr, char * addr) {
	if (!nr) {
		memset(addr,0,BLOCK_SIZE);
		return;
	}
	if (BLOCK_SIZE*nr != lseek(IN, BLOCK_SIZE*nr, SEEK_SET)) {
		get_current_name();
		printf(_("Read error: unable to seek to block in file '%s'\n"),
		       current_name);
		memset(addr,0,BLOCK_SIZE);
		errors_uncorrected = 1;
	} else if (BLOCK_SIZE != read(IN, addr, BLOCK_SIZE)) {
		get_current_name();
		printf(_("Read error: bad block in file '%s'\n"),
		       current_name);
		memset(addr,0,BLOCK_SIZE);
		errors_uncorrected = 1;
	}
}

/*
 * write_block writes block nr to disk.
 */
static void
write_block(unsigned int nr, char * addr) {
	if (!nr)
		return;
	if (nr < FIRSTZONE || nr >= ZONES) {
		printf(_("Internal error: trying to write bad block\n"
		"Write request ignored\n"));
		errors_uncorrected = 1;
		return;
	}
	if (BLOCK_SIZE*nr != lseek(IN, BLOCK_SIZE*nr, SEEK_SET))
		die(_("seek failed in write_block"));
	if (BLOCK_SIZE != write(IN, addr, BLOCK_SIZE)) {
		get_current_name();
		printf(_("Write error: bad block in file '%s'\n"),
		       current_name);
		errors_uncorrected = 1;
	}
}

/*
 * map-block calculates the absolute block nr of a block in a file.
 * It sets 'changed' if the inode has needed changing, and re-writes
 * any indirect blocks with errors.
 */
static int
map_block(struct minix_inode * inode, unsigned int blknr) {
	unsigned short ind[BLOCK_SIZE>>1];
	unsigned short dind[BLOCK_SIZE>>1];
	int blk_chg, block, result;

	if (blknr<7)
		return check_zone_nr(inode->i_zone + blknr, &changed);
	blknr -= 7;
	if (blknr<512) {
		block = check_zone_nr(inode->i_zone + 7, &changed);
		read_block(block, (char *) ind);
		blk_chg = 0;
		result = check_zone_nr(blknr + ind, &blk_chg);
		if (blk_chg)
			write_block(block, (char *) ind);
		return result;
	}
	blknr -= 512;
	block = check_zone_nr(inode->i_zone + 8, &changed);
	read_block(block, (char *) dind);
	blk_chg = 0;
	result = check_zone_nr(dind + (blknr/512), &blk_chg);
	if (blk_chg)
		write_block(block, (char *) dind);
	block = result;
	read_block(block, (char *) ind);
	blk_chg = 0;
	result = check_zone_nr(ind + (blknr%512), &blk_chg);
	if (blk_chg)
		write_block(block, (char *) ind);
	return result;
}

static int
map_block2 (struct minix2_inode *inode, unsigned int blknr) {
  	unsigned int ind[BLOCK_SIZE >> 2];
	unsigned int dind[BLOCK_SIZE >> 2];
	unsigned int tind[BLOCK_SIZE >> 2];
	int blk_chg, block, result;

	if (blknr < 7)
		return check_zone_nr2 (inode->i_zone + blknr, &changed);
	blknr -= 7;
	if (blknr < 256) {
		block = check_zone_nr2 (inode->i_zone + 7, &changed);
		read_block (block, (char *) ind);
		blk_chg = 0;
		result = check_zone_nr2 (blknr + ind, &blk_chg);