mount.c revision 53976 
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
35static 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
42static char sccsid[] = "@(#)mount.c	8.25 (Berkeley) 5/8/95";
43#endif
44static const char rcsid[] =
45  "$FreeBSD: head/sbin/mount/mount.c 53976 1999-12-01 02:16:51Z mckusick $";
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
71int debug, fstab_style, verbose;
72
73char   *catopt __P((char *, const char *));
74struct statfs
75       *getmntpt __P((const char *));
76int	hasopt __P((const char *, const char *));
77int	ismounted __P((struct fstab *, struct statfs *, int));
78int	isremountable __P((const char *));
79void	mangle __P((char *, int *, const char **));
80char   *update_options __P((char *, char *, int));
81int	mountfs __P((const char *, const char *, const char *,
82			int, const char *, const char *));
83void	remopt __P((char *, const char *));
84void	prmount __P((struct statfs *));
85void	putfsent __P((const struct statfs *));
86void	usage __P((void));
87char   *flags2opts __P((int));
88
89/* Map from mount options to printable formats. */
90static 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 */
118static const char *
119remountable_fs_names[] = {
120	"ufs", "ffs", "lfs", "ext2fs",
121	0
122};
123
124int
125main(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, have_fstab;
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			mntfromname = NULL;
232			have_fstab = 0;
233			if ((mntbuf = getmntpt(*argv)) == NULL)
234				errx(1, "not currently mounted %s", *argv);
235			/*
236			 * Only get the mntflags from fstab if both mntpoint
237			 * and mntspec are identical. Also handle the special
238			 * case where just '/' is mounted and 'spec' is not
239			 * identical with the one from fstab ('/dev' is missing
240			 * in the spec-string at boot-time).
241			 */
242			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
243				if (strcmp(fs->fs_spec,
244				    mntbuf->f_mntfromname) == 0 &&
245				    strcmp(fs->fs_file,
246				    mntbuf->f_mntonname) == 0) {
247					have_fstab = 1;
248					mntfromname = mntbuf->f_mntfromname;
249				} else if (argv[0][0] == '/' &&
250				    argv[0][1] == '\0') {
251					fs = getfsfile("/");
252					have_fstab = 1;
253					mntfromname = fs->fs_spec;
254				}
255			}
256			if (have_fstab) {
257				options = update_options(options, fs->fs_mntops,
258				    mntbuf->f_flags);
259			} else {
260				mntfromname = mntbuf->f_mntfromname;
261				options = update_options(options, NULL,
262				    mntbuf->f_flags);
263			}
264			rval = mountfs(mntbuf->f_fstypename, mntfromname,
265			    mntbuf->f_mntonname, init_flags, options, 0);
266			break;
267		}
268		if ((fs = getfsfile(*argv)) == NULL &&
269		    (fs = getfsspec(*argv)) == NULL)
270			errx(1, "%s: unknown special file or file system",
271			    *argv);
272		if (BADTYPE(fs->fs_type))
273			errx(1, "%s has unknown file system type",
274			    *argv);
275		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
276		    init_flags, options, fs->fs_mntops);
277		break;
278	case 2:
279		/*
280		 * If -t flag has not been specified, the path cannot be
281		 * found, spec contains either a ':' or a '@', and the
282		 * spec is not a file with those characters, then assume
283		 * that an NFS filesystem is being specified ala Sun.
284		 */
285		if (vfslist == NULL && strpbrk(argv[0], ":@") != NULL &&
286		    access(argv[0], 0) == -1)
287			vfstype = "nfs";
288		rval = mountfs(vfstype,
289		    argv[0], argv[1], init_flags, options, NULL);
290		break;
291	default:
292		usage();
293		/* NOTREACHED */
294	}
295
296	/*
297	 * If the mount was successfully, and done by root, tell mountd the
298	 * good news.  Pid checks are probably unnecessary, but don't hurt.
299	 */
300	if (rval == 0 && getuid() == 0 &&
301	    (mountdfp = fopen(_PATH_MOUNTDPID, "r")) != NULL) {
302		if (fscanf(mountdfp, "%d", &pid) == 1 &&
303		     pid > 0 && kill(pid, SIGHUP) == -1 && errno != ESRCH)
304			err(1, "signal mountd");
305		(void)fclose(mountdfp);
306	}
307
308	exit(rval);
309}
310
311int
312ismounted(fs, mntbuf, mntsize)
313	struct fstab *fs;
314	struct statfs *mntbuf;
315	int mntsize;
316{
317	int i;
318
319	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
320		/* the root file system can always be remounted */
321		return (0);
322
323	for (i = mntsize - 1; i >= 0; --i)
324		if (strcmp(fs->fs_file, mntbuf[i].f_mntonname) == 0 &&
325		    (!isremountable(fs->fs_vfstype) ||
326		     strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0))
327			return (1);
328	return (0);
329}
330
331int
332isremountable(vfsname)
333	const char *vfsname;
334{
335	const char **cp;
336
337	for (cp = remountable_fs_names; *cp; cp++)
338		if (strcmp(*cp, vfsname) == 0)
339			return (1);
340	return (0);
341}
342
343int
344hasopt(mntopts, option)
345	const char *mntopts, *option;
346{
347	int negative, found;
348	char *opt, *optbuf;
349
350	if (option[0] == 'n' && option[1] == 'o') {
351		negative = 1;
352		option += 2;
353	} else
354		negative = 0;
355	optbuf = strdup(mntopts);
356	found = 0;
357	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
358		if (opt[0] == 'n' && opt[1] == 'o') {
359			if (!strcasecmp(opt + 2, option))
360				found = negative;
361		} else if (!strcasecmp(opt, option))
362			found = !negative;
363	}
364	free(optbuf);
365	return (found);
366}
367
368int
369mountfs(vfstype, spec, name, flags, options, mntopts)
370	const char *vfstype, *spec, *name, *options, *mntopts;
371	int flags;
372{
373	/* List of directories containing mount_xxx subcommands. */
374	static const char *edirs[] = {
375		_PATH_SBIN,
376		_PATH_USRSBIN,
377		NULL
378	};
379	const char *argv[100], **edir;
380	struct statfs sf;
381	pid_t pid;
382	int argc, i, status;
383	char *optbuf, execname[MAXPATHLEN + 1], mntpath[MAXPATHLEN];
384
385#if __GNUC__
386	(void)&optbuf;
387	(void)&name;
388#endif
389
390	/* resolve the mountpoint with realpath(3) */
391	(void)checkpath(name, mntpath);
392	name = mntpath;
393
394	if (mntopts == NULL)
395		mntopts = "";
396	if (options == NULL) {
397		if (*mntopts == '\0') {
398			options = "rw";
399		} else {
400			options = mntopts;
401			mntopts = "";
402		}
403	}
404	optbuf = catopt(strdup(mntopts), options);
405
406	if (strcmp(name, "/") == 0)
407		flags |= MNT_UPDATE;
408	if (flags & MNT_FORCE)
409		optbuf = catopt(optbuf, "force");
410	if (flags & MNT_RDONLY)
411		optbuf = catopt(optbuf, "ro");
412	/*
413	 * XXX
414	 * The mount_mfs (newfs) command uses -o to select the
415	 * optimization mode.  We don't pass the default "-o rw"
416	 * for that reason.
417	 */
418	if (flags & MNT_UPDATE)
419		optbuf = catopt(optbuf, "update");
420
421	argc = 0;
422	argv[argc++] = vfstype;
423	mangle(optbuf, &argc, argv);
424	argv[argc++] = spec;
425	argv[argc++] = name;
426	argv[argc] = NULL;
427
428	if (debug) {
429		(void)printf("exec: mount_%s", vfstype);
430		for (i = 1; i < argc; i++)
431			(void)printf(" %s", argv[i]);
432		(void)printf("\n");
433		return (0);
434	}
435
436	switch (pid = fork()) {
437	case -1:				/* Error. */
438		warn("fork");
439		free(optbuf);
440		return (1);
441	case 0:					/* Child. */
442		if (strcmp(vfstype, "ufs") == 0)
443			exit(mount_ufs(argc, (char * const *) argv));
444
445		/* Go find an executable. */
446		for (edir = edirs; *edir; edir++) {
447			(void)snprintf(execname,
448			    sizeof(execname), "%s/mount_%s", *edir, vfstype);
449			execv(execname, (char * const *)argv);
450		}
451		if (errno == ENOENT) {
452			int len = 0;
453			char *cp;
454			for (edir = edirs; *edir; edir++)
455				len += strlen(*edir) + 2;	/* ", " */
456			if ((cp = malloc(len)) == NULL)
457				errx(1, "malloc failed");
458			cp[0] = '\0';
459			for (edir = edirs; *edir; edir++) {
460				strcat(cp, *edir);
461				if (edir[1] != NULL)
462					strcat(cp, ", ");
463			}
464			warn("exec mount_%s not found in %s", vfstype, cp);
465		}
466		exit(1);
467		/* NOTREACHED */
468	default:				/* Parent. */
469		free(optbuf);
470
471		if (waitpid(pid, &status, 0) < 0) {
472			warn("waitpid");
473			return (1);
474		}
475
476		if (WIFEXITED(status)) {
477			if (WEXITSTATUS(status) != 0)
478				return (WEXITSTATUS(status));
479		} else if (WIFSIGNALED(status)) {
480			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
481			return (1);
482		}
483
484		if (verbose) {
485			if (statfs(name, &sf) < 0) {
486				warn("statfs %s", name);
487				return (1);
488			}
489			if (fstab_style)
490				putfsent(&sf);
491			else
492				prmount(&sf);
493		}
494		break;
495	}
496
497	return (0);
498}
499
500void
501prmount(sfp)
502	struct statfs *sfp;
503{
504	int flags;
505	struct opt *o;
506	struct passwd *pw;
507
508	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
509	    sfp->f_fstypename);
510
511	flags = sfp->f_flags & MNT_VISFLAGMASK;
512	for (o = optnames; flags && o->o_opt; o++)
513		if (flags & o->o_opt) {
514			(void)printf(", %s", o->o_name);
515			flags &= ~o->o_opt;
516		}
517	if (sfp->f_owner) {
518		(void)printf(", mounted by ");
519		if ((pw = getpwuid(sfp->f_owner)) != NULL)
520			(void)printf("%s", pw->pw_name);
521		else
522			(void)printf("%d", sfp->f_owner);
523	}
524	if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
525		(void)printf(", writes: sync %ld async %ld",
526		    sfp->f_syncwrites, sfp->f_asyncwrites);
527	if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
528		(void)printf(", reads: sync %ld async %ld",
529		    sfp->f_syncreads, sfp->f_asyncreads);
530	(void)printf(")\n");
531}
532
533struct statfs *
534getmntpt(name)
535	const char *name;
536{
537	struct statfs *mntbuf;
538	int i, mntsize;
539
540	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
541	for (i = mntsize - 1; i >= 0; i--) {
542		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
543		    strcmp(mntbuf[i].f_mntonname, name) == 0)
544			return (&mntbuf[i]);
545	}
546	return (NULL);
547}
548
549char *
550catopt(s0, s1)
551	char *s0;
552	const char *s1;
553{
554	size_t i;
555	char *cp;
556
557	if (s1 == NULL || *s1 == '\0')
558		return s0;
559
560	if (s0 && *s0) {
561		i = strlen(s0) + strlen(s1) + 1 + 1;
562		if ((cp = malloc(i)) == NULL)
563			errx(1, "malloc failed");
564		(void)snprintf(cp, i, "%s,%s", s0, s1);
565	} else
566		cp = strdup(s1);
567
568	if (s0)
569		free(s0);
570	return (cp);
571}
572
573void
574mangle(options, argcp, argv)
575	char *options;
576	int *argcp;
577	const char **argv;
578{
579	char *p, *s;
580	int argc;
581
582	argc = *argcp;
583	for (s = options; (p = strsep(&s, ",")) != NULL;)
584		if (*p != '\0') {
585			if (*p == '-') {
586				argv[argc++] = p;
587				p = strchr(p, '=');
588				if (p) {
589					*p = '\0';
590					argv[argc++] = p+1;
591				}
592			} else if (strcmp(p, "rw") != 0) {
593				argv[argc++] = "-o";
594				argv[argc++] = p;
595			}
596		}
597
598	*argcp = argc;
599}
600
601
602char *
603update_options(opts, fstab, curflags)
604	char *opts;
605	char *fstab;
606	int curflags;
607{
608	char *o, *p;
609	char *cur;
610	char *expopt, *newopt, *tmpopt;
611
612	if (opts == NULL)
613		return strdup("");
614
615	/* remove meta options from list */
616	remopt(fstab, MOUNT_META_OPTION_FSTAB);
617	remopt(fstab, MOUNT_META_OPTION_CURRENT);
618	cur = flags2opts(curflags);
619
620	/*
621	 * Expand all meta-options passed to us first.
622	 */
623	expopt = NULL;
624	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
625		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
626			expopt = catopt(expopt, fstab);
627		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
628			expopt = catopt(expopt, cur);
629		else
630			expopt = catopt(expopt, o);
631	}
632	free(cur);
633	free(opts);
634
635	/*
636	 * Remove previous contradictory arguments. Given option "foo" we
637	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
638	 * and "foo" - so we can deal with possible options like "notice".
639	 */
640	newopt = NULL;
641	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
642		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
643			errx(1, "malloc failed");
644
645		strcpy(tmpopt, "no");
646		strcat(tmpopt, o);
647		remopt(newopt, tmpopt);
648		free(tmpopt);
649
650		if (strncmp("no", o, 2) == 0)
651			remopt(newopt, o+2);
652
653		newopt = catopt(newopt, o);
654	}
655	free(expopt);
656
657	return newopt;
658}
659
660void
661remopt(string, opt)
662	char *string;
663 	const char *opt;
664{
665	char *o, *p, *r;
666
667	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
668		return;
669
670	r = string;
671
672	for (p = string; (o = strsep(&p, ",")) != NULL;) {
673		if (strcmp(opt, o) != 0) {
674			if (*r == ',' && *o != '\0')
675				r++;
676			while ((*r++ = *o++) != '\0')
677			    ;
678			*--r = ',';
679		}
680	}
681	*r = '\0';
682}
683
684void
685usage()
686{
687
688	(void)fprintf(stderr, "%s\n%s\n%s\n",
689"usage: mount [-dfpruvw] [-o options] [-t ufs | external_type] special node",
690"       mount [-adfpruvw] [-t ufs | external_type]",
691"       mount [-dfpruvw] special | node");
692	exit(1);
693}
694
695void
696putfsent(ent)
697	const struct statfs *ent;
698{
699	struct fstab *fst;
700	char *opts;
701
702	opts = flags2opts(ent->f_flags);
703	printf("%s\t%s\t%s %s", ent->f_mntfromname, ent->f_mntonname,
704	    ent->f_fstypename, opts);
705	free(opts);
706
707	if ((fst = getfsspec(ent->f_mntfromname)))
708		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
709	else if ((fst = getfsfile(ent->f_mntonname)))
710		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
711	else if (strcmp(ent->f_fstypename, "ufs") == 0)
712		printf("\t1 1\n");
713	else
714		printf("\t0 0\n");
715}
716
717
718char *
719flags2opts(flags)
720	int flags;
721{
722	char *res;
723
724	res = NULL;
725
726	res = catopt(res, (flags & MNT_RDONLY) ? "ro" : "rw");
727
728	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
729	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
730	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
731	if (flags & MNT_NODEV)		res = catopt(res, "nodev");
732	if (flags & MNT_UNION)		res = catopt(res, "union");
733	if (flags & MNT_ASYNC)		res = catopt(res, "async");
734	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
735	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
736	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
737	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
738	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
739
740	return res;
741}
742