xref: /freebsd/sbin/mount/mount.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
1 /*-
2  * Copyright (c) 1980, 1989, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1980, 1989, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)mount.c	8.25 (Berkeley) 5/8/95";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif /* not lint */
47 
48 #include <sys/param.h>
49 #include <sys/mount.h>
50 #include <sys/stat.h>
51 #include <sys/wait.h>
52 
53 #include <err.h>
54 #include <errno.h>
55 #include <fstab.h>
56 #include <pwd.h>
57 #include <signal.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <unistd.h>
62 
63 #include "extern.h"
64 #include "mntopts.h"
65 #include "pathnames.h"
66 
67 /* `meta' options */
68 #define MOUNT_META_OPTION_FSTAB		"fstab"
69 #define MOUNT_META_OPTION_CURRENT	"current"
70 
71 int debug, fstab_style, verbose;
72 
73 char   *catopt __P((char *, const char *));
74 struct statfs
75        *getmntpt __P((const char *));
76 int	hasopt __P((const char *, const char *));
77 int	ismounted __P((struct fstab *, struct statfs *, int));
78 int	isremountable __P((const char *));
79 void	mangle __P((char *, int *, const char **));
80 char   *update_options __P((char *, char *, int));
81 int	mountfs __P((const char *, const char *, const char *,
82 			int, const char *, const char *));
83 void	remopt __P((char *, const char *));
84 void	prmount __P((struct statfs *));
85 void	putfsent __P((const struct statfs *));
86 void	usage __P((void));
87 char   *flags2opts __P((int));
88 
89 /* Map from mount options to printable formats. */
90 static struct opt {
91 	int o_opt;
92 	const char *o_name;
93 } optnames[] = {
94 	{ MNT_ASYNC,		"asynchronous" },
95 	{ MNT_EXPORTED,		"NFS exported" },
96 	{ MNT_LOCAL,		"local" },
97 	{ MNT_NOATIME,		"noatime" },
98 	{ MNT_NODEV,		"nodev" },
99 	{ MNT_NOEXEC,		"noexec" },
100 	{ MNT_NOSUID,		"nosuid" },
101 	{ MNT_NOSYMFOLLOW,	"nosymfollow" },
102 	{ MNT_QUOTA,		"with quotas" },
103 	{ MNT_RDONLY,		"read-only" },
104 	{ MNT_SYNCHRONOUS,	"synchronous" },
105 	{ MNT_UNION,		"union" },
106 	{ MNT_NOCLUSTERR,	"noclusterr" },
107 	{ MNT_NOCLUSTERW,	"noclusterw" },
108 	{ MNT_SUIDDIR,		"suiddir" },
109 	{ MNT_SOFTDEP,		"soft-updates" },
110 	{ 0, NULL }
111 };
112 
113 /*
114  * List of VFS types that can be remounted without becoming mounted on top
115  * of each other.
116  * XXX Is this list correct?
117  */
118 static const char *
119 remountable_fs_names[] = {
120 	"ufs", "ffs", "lfs", "ext2fs",
121 	0
122 };
123 
124 int
125 main(argc, argv)
126 	int argc;
127 	char * const argv[];
128 {
129 	const char *mntfromname, **vfslist, *vfstype;
130 	struct fstab *fs;
131 	struct statfs *mntbuf;
132 	FILE *mountdfp;
133 	pid_t pid;
134 	int all, ch, i, init_flags, mntsize, rval;
135 	char *options;
136 
137 	all = init_flags = 0;
138 	options = NULL;
139 	vfslist = NULL;
140 	vfstype = "ufs";
141 	while ((ch = getopt(argc, argv, "adfo:prwt:uv")) != -1)
142 		switch (ch) {
143 		case 'a':
144 			all = 1;
145 			break;
146 		case 'd':
147 			debug = 1;
148 			break;
149 		case 'f':
150 			init_flags |= MNT_FORCE;
151 			break;
152 		case 'o':
153 			if (*optarg)
154 				options = catopt(options, optarg);
155 			break;
156 		case 'p':
157 			fstab_style = 1;
158 			verbose = 1;
159 			break;
160 		case 'r':
161 			init_flags |= MNT_RDONLY;
162 			break;
163 		case 't':
164 			if (vfslist != NULL)
165 				errx(1, "only one -t option may be specified");
166 			vfslist = makevfslist(optarg);
167 			vfstype = optarg;
168 			break;
169 		case 'u':
170 			init_flags |= MNT_UPDATE;
171 			break;
172 		case 'v':
173 			verbose = 1;
174 			break;
175 		case 'w':
176 			init_flags &= ~MNT_RDONLY;
177 			break;
178 		case '?':
179 		default:
180 			usage();
181 			/* NOTREACHED */
182 		}
183 	argc -= optind;
184 	argv += optind;
185 
186 #define	BADTYPE(type)							\
187 	(strcmp(type, FSTAB_RO) &&					\
188 	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
189 
190 	rval = 0;
191 	switch (argc) {
192 	case 0:
193 		if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
194 			err(1, "getmntinfo");
195 		if (all) {
196 			while ((fs = getfsent()) != NULL) {
197 				if (BADTYPE(fs->fs_type))
198 					continue;
199 				if (checkvfsname(fs->fs_vfstype, vfslist))
200 					continue;
201 				if (hasopt(fs->fs_mntops, "noauto"))
202 					continue;
203 				if (!(init_flags & MNT_UPDATE) &&
204 				    ismounted(fs, mntbuf, mntsize))
205 					continue;
206 				if (mountfs(fs->fs_vfstype, fs->fs_spec,
207 				    fs->fs_file, init_flags, options,
208 				    fs->fs_mntops))
209 					rval = 1;
210 			}
211 		} else if (fstab_style) {
212 			for (i = 0; i < mntsize; i++) {
213 				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
214 					continue;
215 				putfsent(&mntbuf[i]);
216 			}
217 		} else {
218 			for (i = 0; i < mntsize; i++) {
219 				if (checkvfsname(mntbuf[i].f_fstypename,
220 				    vfslist))
221 					continue;
222 				prmount(&mntbuf[i]);
223 			}
224 		}
225 		exit(rval);
226 	case 1:
227 		if (vfslist != NULL)
228 			usage();
229 
230 		if (init_flags & MNT_UPDATE) {
231 			if ((mntbuf = getmntpt(*argv)) == NULL)
232 				errx(1,
233 				    "unknown special file or file system %s",
234 				    *argv);
235 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
236 				mntfromname = fs->fs_spec;
237 				options = update_options(options, fs->fs_mntops,
238 				    mntbuf->f_flags);
239 			} else {
240 				mntfromname = mntbuf->f_mntfromname;
241 				options = update_options(options, NULL,
242 				    mntbuf->f_flags);
243 			}
244 			rval = mountfs(mntbuf->f_fstypename, mntfromname,
245 			    mntbuf->f_mntonname, init_flags, options, 0);
246 			break;
247 		}
248 		if ((fs = getfsfile(*argv)) == NULL &&
249 		    (fs = getfsspec(*argv)) == NULL)
250 			errx(1, "%s: unknown special file or file system",
251 			    *argv);
252 		if (BADTYPE(fs->fs_type))
253 			errx(1, "%s has unknown file system type",
254 			    *argv);
255 		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
256 		    init_flags, options, fs->fs_mntops);
257 		break;
258 	case 2:
259 		/*
260 		 * If -t flag has not been specified, and spec contains either
261 		 * a ':' or a '@', and the spec is not a file with those
262 		 * characters, then assume that an NFS filesystem is being
263 		 * specified ala Sun.
264 		 */
265 		if (vfslist == NULL && strpbrk(argv[0], ":@") != NULL &&
266 		    access(argv[0], 0) == -1)
267 			vfstype = "nfs";
268 		rval = mountfs(vfstype,
269 		    argv[0], argv[1], init_flags, options, NULL);
270 		break;
271 	default:
272 		usage();
273 		/* NOTREACHED */
274 	}
275 
276 	/*
277 	 * If the mount was successfully, and done by root, tell mountd the
278 	 * good news.  Pid checks are probably unnecessary, but don't hurt.
279 	 */
280 	if (rval == 0 && getuid() == 0 &&
281 	    (mountdfp = fopen(_PATH_MOUNTDPID, "r")) != NULL) {
282 		if (fscanf(mountdfp, "%d", &pid) == 1 &&
283 		     pid > 0 && kill(pid, SIGHUP) == -1 && errno != ESRCH)
284 			err(1, "signal mountd");
285 		(void)fclose(mountdfp);
286 	}
287 
288 	exit(rval);
289 }
290 
291 int
292 ismounted(fs, mntbuf, mntsize)
293 	struct fstab *fs;
294 	struct statfs *mntbuf;
295 	int mntsize;
296 {
297 	int i;
298 
299 	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
300 		/* the root file system can always be remounted */
301 		return (0);
302 
303 	for (i = mntsize - 1; i >= 0; --i)
304 		if (strcmp(fs->fs_file, mntbuf[i].f_mntonname) == 0 &&
305 		    (!isremountable(fs->fs_vfstype) ||
306 		     strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0))
307 			return (1);
308 	return (0);
309 }
310 
311 int
312 isremountable(vfsname)
313 	const char *vfsname;
314 {
315 	const char **cp;
316 
317 	for (cp = remountable_fs_names; *cp; cp++)
318 		if (strcmp(*cp, vfsname) == 0)
319 			return (1);
320 	return (0);
321 }
322 
323 int
324 hasopt(mntopts, option)
325 	const char *mntopts, *option;
326 {
327 	int negative, found;
328 	char *opt, *optbuf;
329 
330 	if (option[0] == 'n' && option[1] == 'o') {
331 		negative = 1;
332 		option += 2;
333 	} else
334 		negative = 0;
335 	optbuf = strdup(mntopts);
336 	found = 0;
337 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
338 		if (opt[0] == 'n' && opt[1] == 'o') {
339 			if (!strcasecmp(opt + 2, option))
340 				found = negative;
341 		} else if (!strcasecmp(opt, option))
342 			found = !negative;
343 	}
344 	free(optbuf);
345 	return (found);
346 }
347 
348 int
349 mountfs(vfstype, spec, name, flags, options, mntopts)
350 	const char *vfstype, *spec, *name, *options, *mntopts;
351 	int flags;
352 {
353 	/* List of directories containing mount_xxx subcommands. */
354 	static const char *edirs[] = {
355 		_PATH_SBIN,
356 		_PATH_USRSBIN,
357 		NULL
358 	};
359 	const char *argv[100], **edir;
360 	struct statfs sf;
361 	pid_t pid;
362 	int argc, i, status;
363 	char *optbuf, execname[MAXPATHLEN + 1], mntpath[MAXPATHLEN];
364 
365 #if __GNUC__
366 	(void)&optbuf;
367 	(void)&name;
368 #endif
369 
370 	/* resolve the mountpoint with realpath(3) */
371 	(void)checkpath(name, mntpath);
372 	name = mntpath;
373 
374 	if (mntopts == NULL)
375 		mntopts = "";
376 	if (options == NULL) {
377 		if (*mntopts == '\0') {
378 			options = "rw";
379 		} else {
380 			options = mntopts;
381 			mntopts = "";
382 		}
383 	}
384 	optbuf = catopt(strdup(mntopts), options);
385 
386 	if (strcmp(name, "/") == 0)
387 		flags |= MNT_UPDATE;
388 	if (flags & MNT_FORCE)
389 		optbuf = catopt(optbuf, "force");
390 	if (flags & MNT_RDONLY)
391 		optbuf = catopt(optbuf, "ro");
392 	/*
393 	 * XXX
394 	 * The mount_mfs (newfs) command uses -o to select the
395 	 * optimization mode.  We don't pass the default "-o rw"
396 	 * for that reason.
397 	 */
398 	if (flags & MNT_UPDATE)
399 		optbuf = catopt(optbuf, "update");
400 
401 	argc = 0;
402 	argv[argc++] = vfstype;
403 	mangle(optbuf, &argc, argv);
404 	argv[argc++] = spec;
405 	argv[argc++] = name;
406 	argv[argc] = NULL;
407 
408 	if (debug) {
409 		(void)printf("exec: mount_%s", vfstype);
410 		for (i = 1; i < argc; i++)
411 			(void)printf(" %s", argv[i]);
412 		(void)printf("\n");
413 		return (0);
414 	}
415 
416 	switch (pid = fork()) {
417 	case -1:				/* Error. */
418 		warn("fork");
419 		free(optbuf);
420 		return (1);
421 	case 0:					/* Child. */
422 		if (strcmp(vfstype, "ufs") == 0)
423 			exit(mount_ufs(argc, (char * const *) argv));
424 
425 		/* Go find an executable. */
426 		for (edir = edirs; *edir; edir++) {
427 			(void)snprintf(execname,
428 			    sizeof(execname), "%s/mount_%s", *edir, vfstype);
429 			execv(execname, (char * const *)argv);
430 		}
431 		if (errno == ENOENT) {
432 			int len = 0;
433 			char *cp;
434 			for (edir = edirs; *edir; edir++)
435 				len += strlen(*edir) + 2;	/* ", " */
436 			if ((cp = malloc(len)) == NULL)
437 				errx(1, "malloc failed");
438 			cp[0] = '\0';
439 			for (edir = edirs; *edir; edir++) {
440 				strcat(cp, *edir);
441 				if (edir[1] != NULL)
442 					strcat(cp, ", ");
443 			}
444 			warn("exec mount_%s not found in %s", vfstype, cp);
445 		}
446 		exit(1);
447 		/* NOTREACHED */
448 	default:				/* Parent. */
449 		free(optbuf);
450 
451 		if (waitpid(pid, &status, 0) < 0) {
452 			warn("waitpid");
453 			return (1);
454 		}
455 
456 		if (WIFEXITED(status)) {
457 			if (WEXITSTATUS(status) != 0)
458 				return (WEXITSTATUS(status));
459 		} else if (WIFSIGNALED(status)) {
460 			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
461 			return (1);
462 		}
463 
464 		if (verbose) {
465 			if (statfs(name, &sf) < 0) {
466 				warn("statfs %s", name);
467 				return (1);
468 			}
469 			if (fstab_style)
470 				putfsent(&sf);
471 			else
472 				prmount(&sf);
473 		}
474 		break;
475 	}
476 
477 	return (0);
478 }
479 
480 void
481 prmount(sfp)
482 	struct statfs *sfp;
483 {
484 	int flags;
485 	struct opt *o;
486 	struct passwd *pw;
487 
488 	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
489 	    sfp->f_fstypename);
490 
491 	flags = sfp->f_flags & MNT_VISFLAGMASK;
492 	for (o = optnames; flags && o->o_opt; o++)
493 		if (flags & o->o_opt) {
494 			(void)printf(", %s", o->o_name);
495 			flags &= ~o->o_opt;
496 		}
497 	if (sfp->f_owner) {
498 		(void)printf(", mounted by ");
499 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
500 			(void)printf("%s", pw->pw_name);
501 		else
502 			(void)printf("%d", sfp->f_owner);
503 	}
504 	if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
505 		(void)printf(", writes: sync %ld async %ld",
506 		    sfp->f_syncwrites, sfp->f_asyncwrites);
507 	(void)printf(")\n");
508 }
509 
510 struct statfs *
511 getmntpt(name)
512 	const char *name;
513 {
514 	struct statfs *mntbuf;
515 	int i, mntsize;
516 
517 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
518 	for (i = 0; i < mntsize; i++)
519 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
520 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
521 			return (&mntbuf[i]);
522 	return (NULL);
523 }
524 
525 char *
526 catopt(s0, s1)
527 	char *s0;
528 	const char *s1;
529 {
530 	size_t i;
531 	char *cp;
532 
533 	if (s1 == NULL || *s1 == '\0')
534 		return s0;
535 
536 	if (s0 && *s0) {
537 		i = strlen(s0) + strlen(s1) + 1 + 1;
538 		if ((cp = malloc(i)) == NULL)
539 			errx(1, "malloc failed");
540 		(void)snprintf(cp, i, "%s,%s", s0, s1);
541 	} else
542 		cp = strdup(s1);
543 
544 	if (s0)
545 		free(s0);
546 	return (cp);
547 }
548 
549 void
550 mangle(options, argcp, argv)
551 	char *options;
552 	int *argcp;
553 	const char **argv;
554 {
555 	char *p, *s;
556 	int argc;
557 
558 	argc = *argcp;
559 	for (s = options; (p = strsep(&s, ",")) != NULL;)
560 		if (*p != '\0') {
561 			if (*p == '-') {
562 				argv[argc++] = p;
563 				p = strchr(p, '=');
564 				if (p) {
565 					*p = '\0';
566 					argv[argc++] = p+1;
567 				}
568 			} else if (strcmp(p, "rw") != 0) {
569 				argv[argc++] = "-o";
570 				argv[argc++] = p;
571 			}
572 		}
573 
574 	*argcp = argc;
575 }
576 
577 
578 char *
579 update_options(opts, fstab, curflags)
580 	char *opts;
581 	char *fstab;
582 	int curflags;
583 {
584 	char *o, *p;
585 	char *cur;
586 	char *expopt, *newopt, *tmpopt;
587 
588 	if (opts == NULL)
589 		return strdup("");
590 
591 	if (fstab == NULL)
592 		fstab = strdup("");
593 
594 	/* remove meta options from list */
595 	remopt(fstab, MOUNT_META_OPTION_FSTAB);
596 	remopt(fstab, MOUNT_META_OPTION_CURRENT);
597 	cur = flags2opts(curflags);
598 
599 	/*
600 	 * Expand all meta-options passed to us first.
601 	 */
602 	expopt = NULL;
603 	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
604 		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
605 			expopt = catopt(expopt, fstab);
606 		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
607 			expopt = catopt(expopt, cur);
608 		else
609 			expopt = catopt(expopt, o);
610 	}
611 	if (fstab == "")
612 		free(fstab);
613 	free(cur);
614 	free(opts);
615 
616 	/*
617 	 * Remove previous contradictory arguments. Given option "foo" we
618 	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
619 	 * and "foo" - so we can deal with possible options like "notice".
620 	 */
621 	newopt = NULL;
622 	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
623 		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
624 			errx(1, "malloc failed");
625 
626 		strcpy(tmpopt, "no");
627 		strcat(tmpopt, o);
628 		remopt(newopt, tmpopt);
629 		free(tmpopt);
630 
631 		if (strncmp("no", o, 2) == 0)
632 			remopt(newopt, o+2);
633 
634 		newopt = catopt(newopt, o);
635 	}
636 	free(expopt);
637 
638 	return newopt;
639 }
640 
641 void
642 remopt(string, opt)
643 	char *string;
644  	const char *opt;
645 {
646 	char *o, *p, *r;
647 
648 	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
649 		return;
650 
651 	r = string;
652 
653 	for (p = string; (o = strsep(&p, ",")) != NULL;) {
654 		if (strcmp(opt, o) != 0) {
655 			if (*r == ',' && *o != '\0')
656 				r++;
657 			while ((*r++ = *o++) != '\0')
658 			    ;
659 			*--r = ',';
660 		}
661 	}
662 	*r = '\0';
663 }
664 
665 void
666 usage()
667 {
668 
669 	(void)fprintf(stderr, "%s\n%s\n%s\n",
670 "usage: mount [-dfpruvw] [-o options] [-t ufs | external_type] special node",
671 "       mount [-adfpruvw] [-t ufs | external_type]",
672 "       mount [-dfpruvw] special | node");
673 	exit(1);
674 }
675 
676 void
677 putfsent(ent)
678 	const struct statfs *ent;
679 {
680 	struct fstab *fst;
681 	char *opts;
682 
683 	opts = flags2opts(ent->f_flags);
684 	printf("%s\t%s\t%s %s", ent->f_mntfromname, ent->f_mntonname,
685 	    ent->f_fstypename, opts);
686 	free(opts);
687 
688 	if ((fst = getfsspec(ent->f_mntfromname)))
689 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
690 	else if ((fst = getfsfile(ent->f_mntonname)))
691 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
692 	else if (strcmp(ent->f_fstypename, "ufs") == 0)
693 		printf("\t1 1\n");
694 	else
695 		printf("\t0 0\n");
696 }
697 
698 
699 char *
700 flags2opts(flags)
701 	int flags;
702 {
703 	char *res;
704 
705 	res = NULL;
706 
707 	res = catopt(res, (flags & MNT_RDONLY) ? "ro" : "rw");
708 
709 	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
710 	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
711 	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
712 	if (flags & MNT_NODEV)		res = catopt(res, "nodev");
713 	if (flags & MNT_UNION)		res = catopt(res, "union");
714 	if (flags & MNT_ASYNC)		res = catopt(res, "async");
715 	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
716 	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
717 	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
718 	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
719 	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
720 
721 	return res;
722 }
723