xref: /freebsd/sbin/fsck_msdosfs/check.c (revision f7bf3122d935e332695aa9dd994ca31909794b49)

/*
 * Copyright (C) 1995, 1996, 1997 Wolfgang Solfrank
 * Copyright (c) 1995 Martin Husemann
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Martin Husemann
 *	and Wolfgang Solfrank.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: check.c,v 1.10 2000/04/25 23:02:51 jdolecek Exp $");
static const char rcsid[] =
  "$FreeBSD$";
#endif /* not lint */

#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

#include "ext.h"
#include "fsutil.h"

int
checkfilesys(const char *fname)
{
	int dosfs;
	struct bootblock boot;
	struct fatEntry *fat = NULL;
	int i, finish_dosdirsection=0;
	int mod = 0;
	int ret = 8;

	rdonly = alwaysno;
	if (!preen)
		printf("** %s", fname);

	dosfs = open(fname, rdonly ? O_RDONLY : O_RDWR, 0);
	if (dosfs < 0 && !rdonly) {
		dosfs = open(fname, O_RDONLY, 0);
		if (dosfs >= 0)
			pwarn(" (NO WRITE)\n");
		else if (!preen)
			printf("\n");
		rdonly = 1;
	} else if (!preen)
		printf("\n");

	if (dosfs < 0) {
		perror("Can't open");
		return 8;
	}

	if (readboot(dosfs, &boot) != FSOK) {
		close(dosfs);
		printf("\n");
		return 8;
	}

	if (checkdirty(dosfs, &boot) && !force) {
		if (preen)
			printf("%s: ", fname);
		printf("FILESYSTEM CLEAN; SKIPPING CHECKS\n");
		ret = 0;
		goto out;
	}

	if (!preen)  {
		if (boot.ValidFat < 0)
			printf("** Phase 1 - Read and Compare FATs\n");
		else
			printf("** Phase 1 - Read FAT\n");
	}

	mod |= readfat(dosfs, &boot, boot.ValidFat >= 0 ? boot.ValidFat : 0, &fat);
	if (mod & FSFATAL) {
		close(dosfs);
		return 8;
	}

	if (boot.ValidFat < 0)
		for (i = 1; i < (int)boot.FATs; i++) {
			struct fatEntry *currentFat;

			mod |= readfat(dosfs, &boot, i, &currentFat);

			if (mod & FSFATAL)
				goto out;

			mod |= comparefat(&boot, fat, currentFat, i);
			free(currentFat);
			if (mod & FSFATAL)
				goto out;
		}

	if (!preen)
		printf("** Phase 2 - Check Cluster Chains\n");

	mod |= checkfat(&boot, fat);
	if (mod & FSFATAL)
		goto out;
	/* delay writing FATs */

	if (!preen)
		printf("** Phase 3 - Checking Directories\n");

	mod |= resetDosDirSection(&boot, fat);
	finish_dosdirsection = 1;
	if (mod & FSFATAL)
		goto out;
	/* delay writing FATs */

	mod |= handleDirTree(dosfs, &boot, fat);
	if (mod & FSFATAL)
		goto out;

	if (!preen)
		printf("** Phase 4 - Checking for Lost Files\n");

	mod |= checklost(dosfs, &boot, fat);
	if (mod & FSFATAL)
		goto out;

	/* now write the FATs */
	if (mod & FSFATMOD) {
		if (ask(1, "Update FATs")) {
			mod |= writefat(dosfs, &boot, fat, mod & FSFIXFAT);
			if (mod & FSFATAL)
				goto out;
		} else
			mod |= FSERROR;
	}

	if (boot.NumBad)
		pwarn("%d files, %d free (%d clusters), %d bad (%d clusters)\n",
		      boot.NumFiles,
		      boot.NumFree * boot.ClusterSize / 1024, boot.NumFree,
		      boot.NumBad * boot.ClusterSize / 1024, boot.NumBad);
	else
		pwarn("%d files, %d free (%d clusters)\n",
		      boot.NumFiles,
		      boot.NumFree * boot.ClusterSize / 1024, boot.NumFree);

	if (mod && (mod & FSERROR) == 0) {
		if (mod & FSDIRTY) {
			if (ask(1, "MARK FILE SYSTEM CLEAN") == 0)
				mod &= ~FSDIRTY;

			if (mod & FSDIRTY) {
				pwarn("MARKING FILE SYSTEM CLEAN\n");
				mod |= writefat(dosfs, &boot, fat, 1);
			} else {
				pwarn("\n***** FILE SYSTEM IS LEFT MARKED AS DIRTY *****\n");
				mod |= FSERROR; /* file system not clean */
			}
		}
	}

	if (mod & (FSFATAL | FSERROR))
		goto out;

	ret = 0;

    out:
	if (finish_dosdirsection)
		finishDosDirSection();
	free(fat);
	close(dosfs);

	if (mod & (FSFATMOD|FSDIRMOD))
		pwarn("\n***** FILE SYSTEM WAS MODIFIED *****\n");

	return ret;
}

int
checkdirty(int fs, struct bootblock *boot)
{
	off_t off;
	u_char *buffer;
	int ret = 0;

	if (boot->ClustMask == CLUST12_MASK)
		return 0;

	off = boot->ResSectors;
	off *= boot->BytesPerSec;

	buffer = malloc(boot->BytesPerSec);
	if (buffer == NULL) {
		perror("No space for FAT");
		return 1;
	}

	if (lseek(fs, off, SEEK_SET) != off) {
		perror("Unable to read FAT");
		goto err;
	}

	if (read(fs, buffer, boot->BytesPerSec) != boot->BytesPerSec) {
		perror("Unable to read FAT");
		goto err;
	}

	if (buffer[0] == boot->Media && buffer[1] == 0xff &&
	    buffer[2] == 0xff &&
	    ((boot->ClustMask == CLUST16_MASK && buffer[3] == 0x7f) ||
	    (boot->ClustMask == CLUST32_MASK && buffer[3] == 0x0f &&
	    buffer[4] == 0xff && buffer[5] == 0xff && buffer[6] == 0xff &&
	    buffer[7] == 0x07)))
		ret = 0;
	else
		ret = 1;

err:
	free(buffer);
	return ret;
}