xref: /illumos-gate/usr/src/cmd/fs.d/ufs/fsck/main.c (revision b9a41fd3)
1 /*
2  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*	Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T	*/
7 /*	  All Rights Reserved  	*/
8 
9 
10 /*
11  * Copyright (c) 1980, 1986, 1990 The Regents of the University of California.
12  * All rights reserved.
13  *
14  * Redistribution and use in source and binary forms are permitted
15  * provided that: (1) source distributions retain this entire copyright
16  * notice and comment, and (2) distributions including binaries display
17  * the following acknowledgement:  ``This product includes software
18  * developed by the University of California, Berkeley and its contributors''
19  * in the documentation or other materials provided with the distribution
20  * and in all advertising materials mentioning features or use of this
21  * software. Neither the name of the University nor the names of its
22  * contributors may be used to endorse or promote products derived
23  * from this software without specific prior written permission.
24  * THIS SOFTWARE IS PROVIDED '`AS IS'' AND WITHOUT ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
26  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
27  */
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 /*
32  * In-core structures:
33  * blockmap[]
34  *	A bitmap of block usage very similar to what's on disk, but
35  *	for the entire filesystem rather than just a cylinder group.
36  *	Zero indicates free, one indicates allocated.  Note that this
37  *	is opposite the interpretation of a cylinder group's free block
38  *	bitmap.
39  *
40  * statemap[]
41  *	Tracks what is known about each inode in the filesystem.
42  *	The fundamental state value is one of USTATE, FSTATE, DSTATE,
43  *	or SSTATE (unallocated, file, directory, shadow/acl).
44  *
45  *	There are optional modifying attributes as well: INZLINK,
46  *	INFOUND, INCLEAR, INORPHAN, and INDELAYD.  The IN prefix
47  *	stands for inode.  INZLINK declares that no links (di_nlink ==
48  *	0) to the inode have been found.  It is used instead of
49  *	examining di_nlink because we've always got the statemap[] in
50  *	memory, and on average the odds are against having any given
51  *	inode in the cache.  INFOUND flags that an inode was
52  *	encountered during the descent of the filesystem.  In other
53  *	words, it's reachable, either by name or by being an acl or
54  *	attribute.  INCLEAR declares an intent to call clri() on an
55  *	inode.
56  *
57  *	INORPHAN indicates that the inode has already been seen once
58  *	in pass3 and determined to be an orphan, so any additional
59  *	encounters don't need to waste cycles redetermining that status.
60  *	It also means we don't ask the user about doing something to the
61  *	inode N times.
62  *
63  *	INDELAYD marks inodes that pass1 determined needed to be truncated.
64  *	They can't be truncated during that pass, because it depends on
65  *	having a stable world for building the block and inode tables from.
66  *
67  *	The IN flags rarely used directly, but instead are
68  *	pre-combined through the {D,F,S}ZLINK, DFOUND, and
69  *	{D,F,S}CLEAR convenience macros.  This mainly matters when
70  *	trying to use grep on the source.
71  *
72  *	Three state-test macros are provided: S_IS_DUNFOUND(),
73  *	S_IS_DVALID(), and S_IS_ZLINK().  The first is true when an
74  *	inode's state indicates that it is either a simple directory
75  *	(DSTATE without the INFOUND or INCLEAR modifiers) or a
76  *	directory with the INZLINK modifier set.  By definition, if a
77  *	directory has zero links, then it can't be found.  As for
78  *	S_IS_DVALID(), it decides if a directory inode is alive.
79  *	Effectively, this translates to whether or not it's been
80  *	flagged for clearing.  If not, then it's valid for current
81  *	purposes.  This is true even if INZLINK is set, as we may find
82  *	a reference to it later.  Finally, S_IS_ZLINK() just picks out
83  *	the INZLINK flag from the state.
84  *
85  *	The S_*() macros all work on a state value.  To simplify a
86  *	bit, the INO_IS_{DUNFOUND,DVALID}() macros take an inode
87  *	number argument.  The inode is looked up in the statemap[] and
88  *	the result handed off to the corresponding S_*() macro.  This
89  *	is partly a holdover from working with different data
90  *	structures (with the same net intent) in the BSD fsck.
91  *
92  * lncntp
93  *	Each entry is initialized to the di_link from the on-disk
94  *	inode.  Each time we find one of those links, we decrement it.
95  *	Once all the traversing is done, we should have a zero.  If we
96  *	have a positive value, then some reference disappeared
97  *	(probably from a directory that got nuked); deal with it by
98  *	fixing the count.  If we have a negative value, then we found
99  *	an extra reference.  This is a can't-happen, except in the
100  *	special case of when we reconnect a directory to its parent or
101  *	to lost+found.  An exact match between lncntp[] and the on-disk
102  *      inode means it's completely unreferenced.
103  *
104  * aclphead
105  *	This is a hash table of the acl inodes in the filesystem.
106  *
107  * aclpsort
108  *	The same acls as in aclphead, but as a simple linear array.
109  *	It is used to hold the acl pointers for sorting and scanning
110  *	in pass3b.
111  */
112 
113 #include <stdio.h>
114 #include <stdlib.h>
115 #include <unistd.h>
116 #include <sys/types.h>
117 #include <sys/param.h>
118 #include <sys/int_types.h>
119 #include <sys/mntent.h>
120 #include <sys/fs/ufs_fs.h>
121 #include <sys/vnode.h>
122 #include <sys/fs/ufs_inode.h>
123 #include <sys/stat.h>
124 #include <fcntl.h>
125 #include <sys/wait.h>
126 #include <sys/mnttab.h>
127 #include <signal.h>
128 #include <string.h>
129 #include <sys/vfstab.h>
130 #include <sys/statvfs.h>
131 #include <sys/filio.h>
132 #include <ustat.h>
133 #include <errno.h>
134 #include "fsck.h"
135 
136 static void usage(void);
137 static long argtol(int, char *, char *, int);
138 static void checkfilesys(char *);
139 static void check_sanity(char *);
140 static void report_limbo(const void *, VISIT, int);
141 
142 #define	QUICK_CHECK	'm'	/* are things ok according to superblock? */
143 #define	ALL_no		'n'	/* auto-answer interactive questions `no' */
144 #define	ALL_NO		'N'	/* auto-answer interactive questions `no' */
145 #define	UFS_OPTS	'o'	/* ufs-specific options, see subopts[] */
146 #define	ECHO_CMD	'V'	/* echo the command line */
147 #define	ALL_yes		'y'	/* auto-answer interactive questions `yes' */
148 #define	ALL_YES		'Y'	/* auto-answer interactive questions `yes' */
149 #define	VERBOSE		'v'	/* be chatty */
150 
151 static char *subopts[] = {
152 #define	PREEN		0	/* non-interactive mode (parent is parallel) */
153 	"p",
154 #define	BLOCK		1	/* alternate superblock */
155 	"b",
156 #define	DEBUG		2	/* yammer */
157 	"d",
158 #define	ONLY_WRITES	3	/* check all writable filesystems */
159 	"w",
160 #define	FORCE		4	/* force checking, even if clean */
161 	"f",
162 	NULL
163 };
164 
165 /*
166  * Filesystems that are `magical' - if they exist in vfstab,
167  * then they have to be mounted for the system to have gotten
168  * far enough to be able to run fsck.  Thus, don't get all
169  * bent out of shape if we're asked to check it and it is mounted.
170  */
171 char *magic_fs[] = {
172 	"",			/* MAGIC_NONE, for normal filesystems */
173 	"/",			/* MAGIC_ROOT */
174 	"/usr",			/* MAGIC_USR */
175 	NULL			/* MAGIC_LIMIT */
176 };
177 
178 void
179 main(int argc, char *argv[])
180 {
181 	int c;
182 	int wflag = 0;
183 	char *suboptions, *value;
184 	struct rlimit rlimit;
185 	extern int optind;
186 	extern char *optarg;
187 
188 	while ((c = getopt(argc, argv, "mnNo:VvyY")) != EOF) {
189 		switch (c) {
190 
191 		case QUICK_CHECK:
192 			mflag++;
193 			break;
194 
195 		case ALL_no:
196 		case ALL_NO:
197 			nflag++;
198 			yflag = 0;
199 			break;
200 
201 		case VERBOSE:
202 			verbose++;
203 			break;
204 
205 		case UFS_OPTS:
206 			/*
207 			 * ufs specific options.
208 			 */
209 			if (optarg == NULL) {
210 				usage();
211 				/*
212 				 * lint does not believe this, nor does it
213 				 * believe #pragma does_not_return(usage)
214 				 */
215 				/* NOTREACHED */
216 			}
217 			suboptions = optarg;
218 			while (*suboptions != '\0') {
219 				switch (getsubopt(&suboptions, subopts,
220 				    &value)) {
221 
222 				case PREEN:
223 					preen++;
224 					break;
225 
226 				case BLOCK:
227 					bflag = argtol(BLOCK, "block",
228 					    value, 10);
229 					(void) printf("Alternate super block "
230 					    "location: %ld.\n",
231 					    (long)bflag);
232 					break;
233 
234 				case DEBUG:
235 					debug++;
236 					verbose++;
237 					break;
238 
239 				case ONLY_WRITES:
240 					/* check only writable filesystems */
241 					wflag++;
242 					break;
243 
244 				case FORCE:
245 					fflag++;
246 					break;
247 
248 				default:
249 					usage();
250 				}
251 			}
252 			break;
253 
254 		case ECHO_CMD:
255 			{
256 				int	opt_count;
257 				char	*opt_text;
258 
259 				(void) printf("fsck -F ufs ");
260 				for (opt_count = 1; opt_count < argc;
261 								opt_count++) {
262 					opt_text = argv[opt_count];
263 					if (opt_text)
264 						(void) printf("%s ", opt_text);
265 				}
266 				(void) printf("\n");
267 			}
268 			break;
269 
270 		case ALL_yes:
271 		case ALL_YES:
272 			yflag++;
273 			nflag = 0;
274 			break;
275 
276 		default:
277 			usage();
278 		}
279 	}
280 	argc -= optind;
281 	argv += optind;
282 
283 	if (argc == 0)
284 		usage();
285 
286 	rflag++; /* check raw devices where we can */
287 	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
288 		(void) signal(SIGINT, catch);
289 	if (preen)
290 		(void) signal(SIGQUIT, catchquit);
291 
292 	/*
293 	 * Push up our allowed memory limit so we can cope
294 	 * with huge file systems.
295 	 */
296 	if (getrlimit(RLIMIT_DATA, &rlimit) == 0) {
297 		rlimit.rlim_cur = rlimit.rlim_max;
298 		(void) setrlimit(RLIMIT_DATA, &rlimit);
299 	}
300 
301 	/*
302 	 * There are a lot of places where we just exit if a problem is
303 	 * found.  This means that we won't necessarily check everything
304 	 * we were asked to.  It would be nice to do everything, and
305 	 * then provide a summary when we're done.  However, the
306 	 * interface doesn't really allow us to do that in any useful
307 	 * way.  So, we'll just bail on the first unrecoverable
308 	 * problem encountered.  If we've been run by the generic
309 	 * wrapper, we were only given one filesystem to check, so the
310 	 * multi-fs case implies being run manually; that means the
311 	 * user can rerun us on the remaining filesystems when it's
312 	 * convenient for them.
313 	 */
314 	while (argc-- > 0) {
315 		if (wflag && !writable(*argv)) {
316 			(void) fprintf(stderr, "not writeable '%s'\n", *argv);
317 			argv++;
318 			if (exitstat == 0)
319 				exitstat = EXBADPARM;
320 		} else {
321 			checkfilesys(*argv++);
322 		}
323 	}
324 	if (interrupted)
325 		exitstat = EXSIGNAL;
326 	exit(exitstat);
327 }
328 
329 /*
330  * A relatively intelligent strtol().  Note that if str is NULL, we'll
331  * exit, so ret does not actually need to be pre-initialized.  Lint
332  * doesn't believe this, and it's harmless enough to make lint happy here.
333  */
334 static long
335 argtol(int flag, char *req, char *str, int base)
336 {
337 	char *cp = str;
338 	long ret = -1;
339 
340 	errno = 0;
341 	if (str != NULL)
342 		ret = strtol(str, &cp, base);
343 	if (cp == str || *cp) {
344 		(void) fprintf(stderr, "-%c flag requires a %s\n", flag, req);
345 		exit(EXBADPARM);
346 	}
347 	if (errno != 0) {
348 		(void) fprintf(stderr, "-%c %s value out of range\n",
349 		    flag, req);
350 	}
351 
352 	return (ret);
353 }
354 
355 /*
356  * Check the specified file system.
357  */
358 static void
359 checkfilesys(char *filesys)
360 {
361 	daddr32_t n_ffree, n_bfree;
362 	char *devstr;
363 	fsck_ino_t files;
364 	daddr32_t blks;
365 	fsck_ino_t inumber;
366 	int zlinks_printed;
367 	fsck_ino_t limbo_victim;
368 	double dbl_nffree, dbl_dsize;
369 	int quiet_dups;
370 
371 	mountfd = -1;
372 	hotroot = 0;
373 	mountedfs = M_NOMNT;
374 	reattached_dir = 0;
375 	broke_dir_link = 0;
376 	iscorrupt = 1;		/* assume failure in setup() */
377 	islog = 0;
378 	islogok = 0;
379 	overflowed_lf = 0;
380 	errorlocked = is_errorlocked(filesys);
381 	limbo_dirs = NULL;
382 
383 	if ((devstr = setup(filesys)) == NULL) {
384 		if (!iscorrupt) {
385 			return;
386 		}
387 
388 		if (preen)
389 			pfatal("CAN'T CHECK FILE SYSTEM.");
390 		if ((exitstat == 0) && (mflag))
391 			exitstat = EXUMNTCHK;
392 		exit(exitstat);
393 	} else {
394 		devname = devstr;
395 	}
396 
397 	if (mflag) {
398 		check_sanity(filesys);
399 		/* NOTREACHED */
400 	}
401 
402 	if (debug)
403 		printclean();
404 
405 	iscorrupt = 0;		/* setup() succeeded, assume good filesystem */
406 
407 	/*
408 	 * 1: scan inodes tallying blocks used
409 	 */
410 	if (!preen) {
411 		/* hotroot is reported as such in setup() if debug is on */
412 		if (mountedfs != M_NOMNT)
413 			(void) printf("** Currently Mounted on %s\n",
414 			    sblock.fs_fsmnt);
415 		else
416 			(void) printf("** Last Mounted on %s\n",
417 			    sblock.fs_fsmnt);
418 		(void) printf("** Phase 1 - Check Blocks and Sizes\n");
419 	}
420 	pass1();
421 
422 	/*
423 	 * 1b: locate first references to duplicates, if any
424 	 */
425 	if (have_dups()) {
426 		if (preen)
427 			pfatal("INTERNAL ERROR: dups with -o p");
428 		(void) printf("** Phase 1b - Rescan For More DUPS\n");
429 		pass1b();
430 	}
431 
432 	/*
433 	 * 2: traverse directories from root to mark all connected directories
434 	 */
435 	if (!preen)
436 		(void) printf("** Phase 2 - Check Pathnames\n");
437 	pass2();
438 
439 	/*
440 	 * 3a: scan inodes looking for disconnected directories.
441 	 */
442 	if (!preen)
443 		(void) printf("** Phase 3a - Check Connectivity\n");
444 	pass3a();
445 
446 	/*
447 	 * 3b: check acls
448 	 */
449 	if (!preen)
450 		(void) printf("** Phase 3b - Verify Shadows/ACLs\n");
451 	pass3b();
452 
453 	/*
454 	 * 4: scan inodes looking for disconnected files; check reference counts
455 	 */
456 	if (!preen)
457 		(void) printf("** Phase 4 - Check Reference Counts\n");
458 	pass4();
459 
460 	/*
461 	 * 5: check and repair resource counts in cylinder groups
462 	 */
463 	if (!preen)
464 		(void) printf("** Phase 5 - Check Cylinder Groups\n");
465 recount:
466 	pass5();
467 
468 	if (overflowed_lf) {
469 		iscorrupt = 1;
470 	}
471 
472 	if (mountedfs == M_RW) {
473 		iscorrupt = 1;
474 	}
475 
476 	if (have_dups()) {
477 		quiet_dups = (reply("LIST REMAINING DUPS") == 0);
478 		if (report_dups(quiet_dups) > 0)
479 			iscorrupt = 1;
480 
481 		(void) printf("WARNING: DATA LOSS MAY HAVE OCCURRED DUE TO "
482 		    "DUP BLOCKS.\nVERIFY FILE CONTENTS BEFORE USING.\n");
483 	}
484 
485 	if (limbo_dirs != NULL) {
486 		/*
487 		 * Don't force iscorrupt, as this is sufficiently
488 		 * harmless that the filesystem can be mounted and
489 		 * used.  We just leak some inodes and/or blocks.
490 		 */
491 		pwarn("Orphan directories not cleared or reconnected:\n");
492 
493 		twalk(limbo_dirs, report_limbo);
494 
495 		while (limbo_dirs != NULL) {
496 			limbo_victim = *(fsck_ino_t *)limbo_dirs;
497 			if (limbo_victim != NULL) {
498 				(void) tdelete((void *)limbo_victim,
499 				    &limbo_dirs,
500 				    ino_t_cmp);
501 			}
502 		}
503 
504 		rerun = 1;
505 	}
506 
507 	if (iscorrupt) {
508 		(void) printf("FILESYSTEM MAY STILL BE INCONSISTENT.\n");
509 		rerun = 1;
510 	}
511 
512 	/*
513 	 * iscorrupt must be stable at this point.
514 	 * updateclean() returns true when it had to discard the log.
515 	 * This can only happen once, since sblock.fs_logbno gets
516 	 * cleared as part of that operation.
517 	 */
518 	if (updateclean()) {
519 		if (!preen)
520 			(void) printf(
521 			    "Log was discarded, updating cyl groups\n");
522 		goto recount;
523 	}
524 
525 	if (debug)
526 		printclean();
527 
528 	ckfini();
529 
530 	/*
531 	 * print out summary statistics
532 	 */
533 	n_ffree = sblock.fs_cstotal.cs_nffree;
534 	n_bfree = sblock.fs_cstotal.cs_nbfree;
535 	files = maxino - UFSROOTINO - sblock.fs_cstotal.cs_nifree - n_files;
536 	blks = n_blks +
537 	    sblock.fs_ncg * (cgdmin(&sblock, 0) - cgsblock(&sblock, 0));
538 	blks += cgsblock(&sblock, 0) - cgbase(&sblock, 0);
539 	blks += howmany(sblock.fs_cssize, sblock.fs_fsize);
540 	blks = maxfsblock - (n_ffree + sblock.fs_frag * n_bfree) - blks;
541 	if (debug && (files > 0 || blks > 0)) {
542 		countdirs = sblock.fs_cstotal.cs_ndir - countdirs;
543 		pwarn("Reclaimed: %d directories, %d files, %lld fragments\n",
544 		    countdirs, files - countdirs,
545 		    (longlong_t)blks);
546 	}
547 
548 	dbl_nffree = (double)n_ffree;
549 	dbl_dsize = (double)sblock.fs_dsize;
550 
551 	if (!verbose) {
552 		/*
553 		 * Done as one big string to try for a single write,
554 		 * so the output doesn't get interleaved with other
555 		 * preening fscks.
556 		 */
557 		pwarn("%ld files, %lld used, %lld free "
558 		    "(%lld frags, %lld blocks, %.1f%% fragmentation)\n",
559 		    (long)n_files, (longlong_t)n_blks,
560 		    (longlong_t)n_ffree + sblock.fs_frag * n_bfree,
561 		    (longlong_t)n_ffree, (longlong_t)n_bfree,
562 		    (dbl_nffree * 100.0) / dbl_dsize);
563 	} else {
564 		pwarn("\nFilesystem summary:\n");
565 		pwarn("Inodes in use: %ld\n", (long)n_files);
566 		pwarn("Blocks in use: %lld\n", (longlong_t)n_blks);
567 		pwarn("Total free fragments: %lld\n",
568 		    (longlong_t)n_ffree + sblock.fs_frag * n_bfree);
569 		pwarn("Free fragments not in blocks: %lld\n",
570 		    (longlong_t)n_ffree);
571 		pwarn("Total free blocks: %lld\n", (longlong_t)n_bfree);
572 		pwarn("Fragment/block fragmentation: %.1f%%\n",
573 		    (dbl_nffree * 100.0) / dbl_dsize);
574 		pwarn("");
575 
576 		if (files < 0)
577 			pwarn("%d inodes missing\n", -files);
578 		if (blks < 0)
579 			pwarn("%lld blocks missing\n", -(longlong_t)blks);
580 
581 		zlinks_printed = 0;
582 		for (inumber = UFSROOTINO; inumber < maxino; inumber++) {
583 			if (S_IS_ZLINK(statemap[inumber])) {
584 				if (zlinks_printed == 0) {
585 					pwarn("The following zero "
586 					    "link count inodes remain:");
587 				}
588 				if (zlinks_printed) {
589 					if ((zlinks_printed % 9) == 0)
590 						(void) puts(",\n");
591 					else
592 						(void) puts(", ");
593 				}
594 				(void) printf("%u", inumber);
595 				zlinks_printed++;
596 			}
597 		}
598 		if ((zlinks_printed != 0) && ((zlinks_printed % 9) != 0))
599 			(void) putchar('\n');
600 	}
601 
602 	/*
603 	 * Clean up after ourselves, so we can do the next filesystem.
604 	 */
605 	free_dup_state();
606 	inocleanup();
607 	free(blockmap);
608 	free(statemap);
609 	free((void *)lncntp);
610 	lncntp = NULL;
611 	blockmap = NULL;
612 	statemap = NULL;
613 	if (iscorrupt && exitstat == 0)
614 		exitstat = EXFNDERRS;
615 	if (fsmodified)
616 		(void) printf("\n***** FILE SYSTEM WAS MODIFIED *****\n");
617 	if (overflowed_lf)
618 		(void) printf("\n***** %s FULL, MUST REMOVE ENTRIES *****\n",
619 		    lfname);
620 	if (reattached_dir) {
621 		(void) printf("ORPHANED DIRECTORIES REATTACHED; DIR LINK "
622 		    "COUNTS MAY NOT BE CORRECT.\n");
623 		rerun = 1;
624 	}
625 	if (broke_dir_link) {
626 		(void) printf(
627 		    "DIRECTORY HARDLINK BROKEN; LOOPS MAY STILL EXIST.\n");
628 		rerun = 1;
629 	}
630 	if (iscorrupt)
631 		(void) printf("***** FILE SYSTEM IS BAD *****\n");
632 
633 	if (rerun)
634 		(void) printf("\n***** PLEASE RERUN FSCK *****\n");
635 
636 	if ((exitstat == 0) &&
637 	    (((mountedfs != M_NOMNT) && !errorlocked) || hotroot)) {
638 		exitstat = EXROOTOKAY;
639 	}
640 
641 	if ((exitstat == 0) && rerun)
642 		exitstat = EXFNDERRS;
643 
644 	if (mountedfs != M_NOMNT) {
645 		if (!fsmodified)
646 			return;
647 		/*
648 		 * _FIOFFS is much more effective than a simple sync().
649 		 * Note that the original fswritefd was discarded in
650 		 * ckfini().
651 		 */
652 		fswritefd = open(devstr, O_RDWR, 0);
653 		if (fswritefd != -1) {
654 			(void) ioctl(fswritefd, _FIOFFS, NULL);
655 			(void) close(fswritefd);
656 		}
657 
658 		if (!preen)
659 			(void) printf("\n***** REBOOT NOW *****\n");
660 
661 		exitstat = EXREBOOTNOW;
662 	}
663 }
664 
665 /*
666  * fsck -m: does the filesystem pass cursory examination
667  *
668  * XXX This is very redundant with setup().  The right thing would be
669  *     for setup() to modify its behaviour when mflag is set (less
670  *     chatty, exit instead of return, etc).
671  */
672 void
673 check_sanity(char *filename)
674 {
675 	struct stat64 stbd, stbr;
676 	char *devname;
677 	struct ustat usb;
678 	char vfsfilename[MAXPATHLEN];
679 	struct vfstab vfsbuf;
680 	FILE *vfstab;
681 	struct statvfs vfs_stat;
682 	int found_magic[MAGIC_LIMIT];
683 	int magic_cnt;
684 	int is_magic = 0;
685 	int is_block;
686 
687 	(void) memset((void *)found_magic, 0, sizeof (found_magic));
688 
689 	if (stat64(filename, &stbd) < 0) {
690 		(void) fprintf(stderr,
691 		"ufs fsck: sanity check failed : cannot stat %s\n", filename);
692 		exit(EXNOSTAT);
693 	}
694 
695 	if ((stbd.st_mode & S_IFMT) == S_IFBLK) {
696 		is_block = 1;
697 	} else if ((stbd.st_mode & S_IFMT) == S_IFCHR) {
698 		is_block = 0;
699 	} else {
700 		/*
701 		 * In !mflag mode, we allow checking the contents
702 		 * of a file.  Since this is intended primarily for
703 		 * speeding up boot-time checks and allowing for a
704 		 * file complicates the ok-input tests, we'll disallow
705 		 * that option.
706 		 */
707 		(void) fprintf(stderr,
708 			"ufs fsck: sanity check failed: "
709 			"%s not block or character device\n",
710 			filename);
711 		exit(EXNOSTAT);
712 	}
713 
714 	/*
715 	 * Determine if this is the root file system via vfstab. Give up
716 	 * silently on failures. The whole point of this is to be tolerant
717 	 * of the magic file systems being already mounted.
718 	 */
719 	if ((vfstab = fopen(VFSTAB, "r")) != 0) {
720 		for (magic_cnt = 0; magic_cnt < MAGIC_LIMIT; magic_cnt++) {
721 			if (magic_cnt == MAGIC_NONE)
722 				continue;
723 			if (getvfsfile(vfstab, &vfsbuf,
724 			    magic_fs[magic_cnt]) == 0) {
725 				if (is_block)
726 					devname = vfsbuf.vfs_special;
727 				else
728 					devname = vfsbuf.vfs_fsckdev;
729 				if (stat64(devname, &stbr) == 0) {
730 					if (stbr.st_rdev == stbd.st_rdev) {
731 						found_magic[magic_cnt] = 1;
732 						is_magic = magic_cnt;
733 						break;
734 					}
735 				}
736 			}
737 		}
738 	}
739 
740 	/*
741 	 * Only works if filename is a block device or if
742 	 * character and block device has the same dev_t value.
743 	 * This is currently true, but nothing really forces it.
744 	 */
745 	if (!is_magic && (ustat(stbd.st_rdev, &usb) == 0)) {
746 		(void) fprintf(stderr,
747 		    "ufs fsck: sanity check: %s already mounted\n", filename);
748 		exit(EXMOUNTED);
749 	}
750 
751 	if (is_magic) {
752 		(void) strcpy(vfsfilename, magic_fs[is_magic]);
753 		if (statvfs(vfsfilename, &vfs_stat) != 0) {
754 			(void) fprintf(stderr, "ufs fsck: Cannot stat %s\n",
755 			    vfsfilename);
756 			exit(EXNOSTAT);
757 		}
758 
759 		if (!(vfs_stat.f_flag & ST_RDONLY)) {
760 			/*
761 			 * The file system is mounted read/write
762 			 * We need to exit saying this. If it's only
763 			 * mounted readonly, we can continue.
764 			 */
765 
766 			(void) fprintf(stderr,
767 				"ufs fsck: sanity check:"
768 				"%s already mounted read/write\n",
769 				filename);
770 			exit(EXMOUNTED);
771 		}
772 	}
773 
774 	/*
775 	 * We know that at boot, the ufs root file system is mounted
776 	 * read-only first.  After fsck runs, it is remounted as
777 	 * read-write.  Therefore, we do not need to check for different
778 	 * values for fs_state between the root file system and the
779 	 * rest of the file systems.
780 	 */
781 	if (islog && !islogok) {
782 		(void) fprintf(stderr,
783 		    "ufs fsck: sanity check: %s needs checking\n", filename);
784 		exit(EXUMNTCHK);
785 	}
786 	if ((sblock.fs_state + (long)sblock.fs_time == FSOKAY) &&
787 		(sblock.fs_clean == FSCLEAN || sblock.fs_clean == FSSTABLE ||
788 		(sblock.fs_clean == FSLOG && islog))) {
789 		(void) fprintf(stderr,
790 		    "ufs fsck: sanity check: %s okay\n", filename);
791 	} else {
792 		(void) fprintf(stderr,
793 		    "ufs fsck: sanity check: %s needs checking\n", filename);
794 		exit(EXUMNTCHK);
795 	}
796 	exit(EXOKAY);
797 }
798 
799 caddr_t
800 hasvfsopt(struct vfstab *vfs, char *opt)
801 {
802 	struct mnttab mtab;
803 
804 	if (vfs->vfs_mntopts == NULL)
805 		return (NULL);
806 	mtab.mnt_mntopts = vfs->vfs_mntopts;
807 	return (hasmntopt(&mtab, opt));
808 }
809 
810 void
811 usage(void)
812 {
813 	(void) fprintf(stderr,
814 	    "ufs usage: fsck [-F ufs] [-m] [-n] [-V] [-v] [-y] "
815 	    "[-o p,b=#,w,f] [special ....]\n");
816 
817 	exit(EXBADPARM);
818 }
819 
820 /*ARGSUSED*/
821 static void
822 report_limbo(const void *node, VISIT order, int level)
823 {
824 	fsck_ino_t ino = *(fsck_ino_t *)node;
825 
826 	if ((order == postorder) || (order == leaf)) {
827 		(void) printf("    Inode %d\n", ino);
828 	}
829 }
830