xref: /titanic_51/usr/src/cmd/fs.d/mount.c (revision 3f84190c280ddf5917fb4682f34fdaa328ee195c)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
22 /*	  All Rights Reserved  	*/
23 
24 
25 /*
26  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 /*
30  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
31  */
32 
33 #include	<stdio.h>
34 #include	<stdio_ext.h>
35 #include 	<limits.h>
36 #include 	<fcntl.h>
37 #include 	<unistd.h>
38 #include	<stdlib.h>
39 #include	<string.h>
40 #include	<stdarg.h>
41 #include	<sys/types.h>
42 #include	<sys/stat.h>
43 #include	<sys/statvfs.h>
44 #include	<errno.h>
45 #include	<sys/mnttab.h>
46 #include	<sys/mntent.h>
47 #include	<sys/mount.h>
48 #include	<sys/vfstab.h>
49 #include	<sys/param.h>
50 #include	<sys/wait.h>
51 #include	<sys/signal.h>
52 #include	<sys/resource.h>
53 #include	<stropts.h>
54 #include	<sys/conf.h>
55 #include	<locale.h>
56 #include	"fslib.h"
57 
58 #define	VFS_PATH	"/usr/lib/fs"
59 #define	ALT_PATH	"/etc/fs"
60 #define	REMOTE		"/etc/dfs/fstypes"
61 
62 #define	ARGV_MAX	16
63 #define	TIME_MAX	50
64 #define	FSTYPE_MAX	8
65 #define	REMOTE_MAX	64
66 
67 #define	OLD	0
68 #define	NEW	1
69 
70 #define	READONLY	0
71 #define	READWRITE	1
72 #define	SUID 		2
73 #define	NOSUID		3
74 #define	SETUID 		4
75 #define	NOSETUID	5
76 #define	DEVICES		6
77 #define	NODEVICES	7
78 
79 #define	FORMAT	"%a %b %e %H:%M:%S %Y\n"	/* date time format */
80 				/* a - abbreviated weekday name */
81 				/* b - abbreviated month name */
82 				/* e - day of month */
83 				/* H - hour */
84 				/* M - minute */
85 				/* S - second */
86 				/* Y - Year */
87 				/* n - newline */
88 
89 /*
90  * The fs-local method understands this exit code to mean that one or
91  * more failures occurred and that all the failures were of attempted
92  * lofs mounts.
93  */
94 #define	ALL_LOFS_FAILURES	111
95 
96 extern int	optind;
97 extern char	*optarg;
98 
99 extern void	usage(void);
100 extern char	*flags(char *, int);
101 extern char	*remote(char *, FILE *);
102 extern char	*default_fstype(char *);
103 
104 char	*myopts[] = {
105 	MNTOPT_RO,
106 	MNTOPT_RW,
107 	MNTOPT_SUID,
108 	MNTOPT_NOSUID,
109 	MNTOPT_SETUID,
110 	MNTOPT_NOSETUID,
111 	MNTOPT_DEVICES,
112 	MNTOPT_NODEVICES,
113 	NULL
114 };
115 
116 static char	*myname;		/* point to argv[0] */
117 
118 /*
119  * Set the limit to double the number of characters a user should be allowed to
120  * type in one line.
121  * This should cover the different shells, which don't use POSIX_MAX_INPUT,
122  * and should cover the case where a long option string can be in
123  * the /etc/vfstab file.
124  */
125 char	mntflags[(_POSIX_MAX_INPUT+1) * 2];
126 
127 char	realdir[MAXPATHLEN];	/* buffer for realpath() calls */
128 char	*vfstab = VFSTAB;
129 char	*mnttab = MNTTAB;
130 char	*specific_opts;		/* holds specific mount options */
131 char	*generic_opts;		/* holds generic mount options */
132 int	maxrun;
133 int	nrun;
134 int	failcnt;		/* total count of failures */
135 int	lofscnt;		/* presence of lofs prohibits parallel */
136 				/* mounting */
137 int	lofsfail;		/* count of failures of lofs mounts */
138 int	exitcode;
139 int	aflg, cflg, fflg, Fflg, gflg, oflg, pflg, rflg, vflg, Vflg, mflg, Oflg,
140 	dashflg, questflg, dflg, qflg;
141 
142 
143 /*
144  * Each vfsent_t describes a vfstab entry.  It is used to manage and cleanup
145  * each child that performs the particular mount for the entry.
146  */
147 
148 typedef struct vfsent {
149 	struct vfstab	v;		/* the vfstab entry */
150 	char		*rpath;		/* resolved pathname so far */
151 	int		mlevel;		/* how deep is this mount point */
152 	int		order;		/* vfstab serial order of this vfs */
153 	int		flag;
154 	pid_t		pid;		/* the pid of this mount process */
155 	int		exitcode;	/* process's exitcode */
156 #define	RDPIPE		0
157 #define	WRPIPE		1
158 	int		sopipe[2];	/* pipe attached to child's stdout */
159 	int		sepipe[2];	/* pipe attached to child's stderr */
160 	struct vfsent	*next;		/* used when in linked list */
161 } vfsent_t;
162 
163 #define	VRPFAILED	0x01		/* most recent realpath failed on */
164 					/* this mount point */
165 #define	VNOTMOUNTED	0x02		/* mount point could not be mounted */
166 
167 vfsent_t	*vfsll, *vfslltail;	/* head and tail of the global */
168 					/* linked list of vfstab entries */
169 vfsent_t	**vfsarray;		/* global array of vfsent_t's */
170 int		vfsarraysize;		/* length of the list */
171 
172 /*
173  * This structure is used to build a linked list of
174  * mnttab structures from /etc/mnttab.
175  */
176 typedef struct mountent {
177 	struct extmnttab	*ment;
178 	int		flag;
179 	struct mountent	*next;
180 } mountent_t;
181 
182 #define	MSORTED		0x1
183 
184 static vfsent_t **make_vfsarray(char **, int);
185 static vfsent_t	*new_vfsent(struct vfstab *, int);
186 static vfsent_t *getvfsall(char *, int);
187 
188 static void	doexec(char *, char **);
189 static void	nomem();
190 static void	cleanup(int);
191 static char	*setrpath(vfsent_t *);
192 static int	dowait();
193 static int	setup_iopipe(vfsent_t *);
194 static void	setup_output(vfsent_t *);
195 static void	doio(vfsent_t *);
196 static void	do_mounts();
197 static int	parmount(char **, int, char *);
198 static int	mlevelcmp(const void *, const void *);
199 static int	mordercmp(const void *, const void *);
200 static int	check_fields(char *, char *);
201 static int	cleanupkid(pid_t, int);
202 static void	print_mnttab(int, int);
203 static void	vfserror(int, char *);
204 static void	mnterror(int);
205 static int	ignore(char *);
206 
207 /*
208  * This is /usr/sbin/mount: the generic command that in turn
209  * execs the appropriate /usr/lib/fs/{fstype}/mount.
210  * The -F flag and argument are NOT passed.
211  * If the usr file system is not mounted a duplicate copy
212  * can be found in /sbin and this version execs the
213  * appropriate /etc/fs/{fstype}/mount
214  *
215  * If the -F fstype, special or directory are missing,
216  * /etc/vfstab is searched to fill in the missing arguments.
217  *
218  * -V will print the built command on the stdout.
219  * It isn't passed either.
220  */
221 int
222 main(int argc, char *argv[])
223 {
224 	char	*special,	/* argument of special/resource */
225 	    *mountp,		/* argument of mount directory */
226 	    *fstype,		/* wherein the fstype name is filled */
227 	    *newargv[ARGV_MAX],	/* arg list for specific command */
228 	    *farg = NULL, *Farg = NULL;
229 	int	ii, ret, cc, fscnt;
230 	struct stat64	stbuf;
231 	struct vfstab	vget, vref;
232 	mode_t mode;
233 	FILE	*fd;
234 
235 	(void) setlocale(LC_ALL, "");
236 
237 #if !defined(TEXT_DOMAIN)
238 #define	TEXT_DOMAIN "SYS_TEST"
239 #endif
240 	(void) textdomain(TEXT_DOMAIN);
241 
242 	myname = strrchr(argv[0], '/');
243 	if (myname)
244 		myname++;
245 	else
246 		myname = argv[0];
247 	if (myname == 0) myname = "path unknown";
248 
249 	/* Process the args.  */
250 
251 	while ((cc = getopt(argc, argv, "?acd:f:F:gmno:pqrvVO")) != -1)
252 		switch (cc) {
253 			case 'a':
254 				aflg++;
255 				break;
256 			case 'c':
257 				cflg++;
258 				break;
259 
260 #ifdef DEBUG
261 			case 'd':
262 				dflg = atoi(optarg);
263 				break;
264 #endif
265 
266 			case 'f':
267 				fflg++;
268 				farg = optarg;
269 				break;
270 			case 'F':
271 				Fflg++;
272 				Farg = optarg;
273 				break;
274 			case 'g':
275 				gflg++;
276 				break;
277 			case 'm':
278 				mflg++;
279 				break; /* do not update /etc/mnttab */
280 			case 'o':
281 				oflg++;
282 				if ((specific_opts = strdup(optarg)) == NULL)
283 					nomem();
284 				break; /* fstype dependent options */
285 			case 'O':
286 				Oflg++;
287 				break;
288 			case 'p':
289 				pflg++;
290 				break;
291 			case 'q':
292 				qflg++;
293 				break;
294 			case 'r':
295 				rflg++;
296 				generic_opts = "ro";
297 				break;
298 			case 'v':
299 				vflg++;
300 				break;
301 			case 'V':
302 				Vflg++;
303 				break;
304 			case '?':
305 				questflg++;
306 				break;
307 		}
308 
309 	/* copy '--' to specific */
310 	if (strcmp(argv[optind-1], "--") == 0)
311 		dashflg++;
312 
313 	/* option checking */
314 	/* more than two args not allowed if !aflg */
315 	if (!aflg && (argc - optind > 2))
316 		usage();
317 
318 	/* pv mututally exclusive */
319 	if (pflg + vflg + aflg > 1) {
320 		fprintf(stderr, gettext
321 		    ("%s: -a, -p, and -v are mutually exclusive\n"),
322 		    myname);
323 		usage();
324 	}
325 
326 	/*
327 	 * Can't have overlaying mounts on the same mount point during
328 	 * a parallel mount.
329 	 */
330 	if (aflg && Oflg) {
331 		fprintf(stderr, gettext
332 		    ("%s: -a and -O are mutually exclusive\n"), myname);
333 		usage();
334 	}
335 
336 	/* dfF mutually exclusive */
337 	if (fflg + Fflg > 1) {
338 		fprintf(stderr, gettext
339 		    ("%s: More than one FSType specified\n"), myname);
340 		usage();
341 	}
342 
343 	/* no arguments, only allow p,v,V or [F]? */
344 	if (!aflg && optind == argc) {
345 		if (cflg || fflg || mflg || oflg || rflg || qflg)
346 			usage();
347 
348 		if (Fflg && !questflg)
349 			usage();
350 
351 		if (questflg) {
352 			if (Fflg) {
353 				newargv[2] = "-?";
354 				newargv[3] = NULL;
355 				doexec(Farg, newargv);
356 			}
357 			usage();
358 		}
359 	}
360 
361 	if (questflg)
362 		usage();
363 
364 	/* one or two args, allow any but p,v */
365 	if (optind != argc && (pflg || vflg)) {
366 		fprintf(stderr,
367 gettext("%s: Cannot use -p and -v with arguments\n"), myname);
368 		usage();
369 	}
370 
371 
372 	/* if only reporting mnttab, generic prints mnttab and exits */
373 	if (!aflg && optind == argc) {
374 		if (Vflg) {
375 			printf("%s", myname);
376 			if (pflg)
377 				printf(" -p");
378 			if (vflg)
379 				printf(" -v");
380 			printf("\n");
381 			exit(0);
382 		}
383 
384 		print_mnttab(vflg, pflg);
385 		exit(0);
386 	}
387 
388 	/*
389 	 * Get filesystem type here.  If "-F FStype" is specified, use
390 	 * that fs type.  Otherwise, determine the fs type from /etc/vfstab
391 	 * if the entry exists.  Otherwise, determine the local or remote
392 	 * fs type from /etc/default/df or /etc/dfs/fstypes respectively.
393 	 */
394 	if (fflg) {
395 		if ((strcmp(farg, "S51K") != 0) &&
396 		    (strcmp(farg, "S52K") != 0)) {
397 			fstype = farg;
398 		}
399 		else
400 			fstype = "ufs";
401 	} else /* if (Fflg) */
402 		fstype = Farg;
403 
404 	fscnt = argc - optind;
405 	if (aflg && (fscnt != 1))
406 		exit(parmount(argv + optind, fscnt, fstype));
407 
408 	/*
409 	 * Then don't bother with the parallel over head.  Everything
410 	 * from this point is simple/normal single execution.
411 	 */
412 	aflg = 0;
413 
414 	/* get special and/or mount-point from arg(s) */
415 	if (fscnt == 2)
416 		special = argv[optind++];
417 	else
418 		special = NULL;
419 	if (optind < argc)
420 		mountp = argv[optind++];
421 	else
422 		mountp = NULL;
423 
424 	/* lookup only if we need to */
425 	if (fstype == NULL || specific_opts == NULL || special == NULL ||
426 	    mountp == NULL) {
427 		if ((fd = fopen(vfstab, "r")) == NULL) {
428 			if (fstype == NULL || special == NULL ||
429 			    mountp == NULL) {
430 				fprintf(stderr, gettext(
431 				    "%s: Cannot open %s\n"),
432 				    myname, vfstab);
433 				exit(1);
434 			} else {
435 				/*
436 				 * No vfstab, but we know what we want
437 				 * to mount.
438 				 */
439 				goto out;
440 			}
441 		}
442 		vfsnull(&vref);
443 		vref.vfs_special = special;
444 		vref.vfs_mountp = mountp;
445 		vref.vfs_fstype = fstype;
446 
447 		/* get a vfstab entry matching mountp or special */
448 		while ((ret = getvfsany(fd, &vget, &vref)) > 0)
449 			vfserror(ret, vget.vfs_special);
450 
451 		/* if no entry and there was only one argument */
452 		/* then the argument could be the special */
453 		/* and not mount point as we thought earlier */
454 		if (ret == -1 && special == NULL) {
455 			rewind(fd);
456 			special = vref.vfs_special = mountp;
457 			mountp = vref.vfs_mountp = NULL;
458 			/* skip erroneous lines; they were reported above */
459 			while ((ret = getvfsany(fd, &vget, &vref)) > 0)
460 				;
461 		}
462 
463 		fclose(fd);
464 
465 		if (ret == 0) {
466 			if (fstype == NULL)
467 				fstype = vget.vfs_fstype;
468 			if (special == NULL)
469 				special = vget.vfs_special;
470 			if (mountp == NULL)
471 				mountp = vget.vfs_mountp;
472 			if (oflg == 0 && vget.vfs_mntopts) {
473 				oflg++;
474 				specific_opts = vget.vfs_mntopts;
475 			}
476 		} else if (special == NULL) {
477 			if (stat64(mountp, &stbuf) == -1) {
478 				fprintf(stderr, gettext("%s: cannot stat %s\n"),
479 				    myname, mountp);
480 				exit(2);
481 			}
482 			if (((mode = (stbuf.st_mode & S_IFMT)) == S_IFBLK) ||
483 			    (mode == S_IFCHR)) {
484 				fprintf(stderr,
485 gettext("%s: mount point cannot be determined\n"),
486 				    myname);
487 				exit(1);
488 			} else
489 				{
490 				fprintf(stderr,
491 gettext("%s: special cannot be determined\n"),
492 				    myname);
493 				exit(1);
494 			}
495 		} else if (fstype == NULL)
496 			fstype = default_fstype(special);
497 	}
498 
499 out:
500 	if (realpath(mountp, realdir) == NULL) {
501 		(void) fprintf(stderr, "mount: ");
502 		perror(mountp);
503 		exit(1);
504 	}
505 
506 	if ((mountp = strdup(realdir)) == NULL)
507 		nomem();
508 
509 	if (check_fields(fstype, mountp))
510 		exit(1);
511 
512 	/* create the new arg list, and end the list with a null pointer */
513 	ii = 2;
514 	if (cflg)
515 		newargv[ii++] = "-c";
516 	if (gflg)
517 		newargv[ii++] = "-g";
518 	if (mflg)
519 		newargv[ii++] = "-m";
520 	/*
521 	 * The q option needs to go before the -o option as some
522 	 * filesystems complain during first pass option parsing.
523 	 */
524 	if (qflg)
525 		newargv[ii++] = "-q";
526 	if (oflg) {
527 		newargv[ii++] = "-o";
528 		newargv[ii++] = specific_opts;
529 	}
530 	if (Oflg)
531 		newargv[ii++] = "-O";
532 	if (rflg)
533 		newargv[ii++] = "-r";
534 	if (dashflg)
535 		newargv[ii++] = "--";
536 	newargv[ii++] = special;
537 	newargv[ii++] = mountp;
538 	newargv[ii] = NULL;
539 
540 	doexec(fstype, newargv);
541 	return (0);
542 }
543 
544 void
545 usage(void)
546 {
547 	fprintf(stderr,	gettext("Usage:\n%s [-v | -p]\n"), myname);
548 	fprintf(stderr, gettext(
549 	    "%s [-F FSType] [-V] [current_options] [-o specific_options]"),
550 	    myname);
551 	fprintf(stderr, gettext("\n\t{special | mount_point}\n"));
552 
553 	fprintf(stderr, gettext(
554 	    "%s [-F FSType] [-V] [current_options] [-o specific_options]"),
555 	    myname);
556 	fprintf(stderr, gettext("\n\tspecial mount_point\n"));
557 
558 	fprintf(stderr, gettext(
559 	"%s -a [-F FSType ] [-V] [current_options] [-o specific_options]\n"),
560 	    myname);
561 	fprintf(stderr, gettext("\t[mount_point ...]\n"));
562 
563 	exit(1);
564 }
565 
566 /*
567  * Get rid of "dev=[hex string]" clause, if any.  It's not legal
568  * when printing in vfstab format.
569  */
570 void
571 elide_dev(char *mntopts)
572 {
573 	char *dev, *other;
574 
575 	if (mntopts != NULL) {
576 		dev = strstr(mntopts, "dev=");
577 		if (dev != NULL) {
578 			other = strpbrk(dev, ",");
579 			if (other == NULL) {
580 				/* last option */
581 				if (dev != mntopts) {
582 					*--dev = '\0';
583 				} else {
584 					*dev = '\0';
585 				}
586 			} else {
587 				/* first or intermediate option */
588 				memmove(dev, other+1, strlen(other+1)+1);
589 			}
590 		}
591 	}
592 }
593 
594 void
595 print_mnttab(int vflg, int pflg)
596 {
597 	FILE	*fd;
598 	FILE	*rfp;			/* this will be NULL if fopen fails */
599 	int	ret;
600 	char	time_buf[TIME_MAX];	/* array to hold date and time */
601 	struct extmnttab	mget;
602 	time_t	ltime;
603 
604 	if ((fd = fopen(mnttab, "r")) == NULL) {
605 		fprintf(stderr, gettext("%s: Cannot open mnttab\n"), myname);
606 		exit(1);
607 	}
608 	rfp = fopen(REMOTE, "r");
609 	while ((ret = getextmntent(fd, &mget, sizeof (struct extmnttab)))
610 	    == 0) {
611 		if (ignore(mget.mnt_mntopts))
612 			continue;
613 		if (mget.mnt_special && mget.mnt_mountp &&
614 		    mget.mnt_fstype && mget.mnt_time) {
615 			ltime = atol(mget.mnt_time);
616 			cftime(time_buf, FORMAT, &ltime);
617 			if (pflg) {
618 				elide_dev(mget.mnt_mntopts);
619 				printf("%s - %s %s - no %s\n",
620 				    mget.mnt_special,
621 				    mget.mnt_mountp,
622 				    mget.mnt_fstype,
623 				    mget.mnt_mntopts != NULL ?
624 				    mget.mnt_mntopts : "-");
625 			} else if (vflg) {
626 				printf("%s on %s type %s %s%s on %s",
627 				    mget.mnt_special,
628 				    mget.mnt_mountp,
629 				    mget.mnt_fstype,
630 				    remote(mget.mnt_fstype, rfp),
631 				    flags(mget.mnt_mntopts, NEW),
632 				    time_buf);
633 			} else
634 				printf("%s on %s %s%s on %s",
635 				    mget.mnt_mountp,
636 				    mget.mnt_special,
637 				    remote(mget.mnt_fstype, rfp),
638 				    flags(mget.mnt_mntopts, OLD),
639 				    time_buf);
640 		}
641 	}
642 	if (ret > 0)
643 		mnterror(ret);
644 }
645 
646 char	*
647 flags(char *mntopts, int flag)
648 {
649 	char	opts[sizeof (mntflags)];
650 	char	*value;
651 	int	rdwr = 1;
652 	int	suid = 1;
653 	int	devices = 1;
654 	int	setuid = 1;
655 
656 	if (mntopts == NULL || *mntopts == '\0')
657 		return ("read/write/setuid/devices");
658 
659 	strcpy(opts, "");
660 	while (*mntopts != '\0')  {
661 		switch (getsubopt(&mntopts, myopts, &value)) {
662 		case READONLY:
663 			rdwr = 0;
664 			break;
665 		case READWRITE:
666 			rdwr = 1;
667 			break;
668 		case SUID:
669 			suid = 1;
670 			break;
671 		case NOSUID:
672 			suid = 0;
673 			break;
674 		case SETUID:
675 			setuid = 1;
676 			break;
677 		case NOSETUID:
678 			setuid = 0;
679 			break;
680 		case DEVICES:
681 			devices = 1;
682 			break;
683 		case NODEVICES:
684 			devices = 0;
685 			break;
686 		default:
687 			/* cat '/' separator to mntflags */
688 			if (*opts != '\0' && value != NULL)
689 				strcat(opts, "/");
690 			strcat(opts, value);
691 			break;
692 		}
693 	}
694 
695 	strcpy(mntflags, "");
696 	if (rdwr)
697 		strcat(mntflags, "read/write");
698 	else if (flag == OLD)
699 		strcat(mntflags, "read only");
700 	else
701 		strcat(mntflags, "read-only");
702 	if (suid) {
703 		if (setuid)
704 			strcat(mntflags, "/setuid");
705 		else
706 			strcat(mntflags, "/nosetuid");
707 		if (devices)
708 			strcat(mntflags, "/devices");
709 		else
710 			strcat(mntflags, "/nodevices");
711 	} else {
712 		strcat(mntflags, "/nosetuid/nodevices");
713 	}
714 	if (*opts != '\0') {
715 		strcat(mntflags, "/");
716 		strcat(mntflags, opts);
717 	}
718 
719 	/*
720 	 * The assumed assertion
721 	 * 	assert (strlen(mntflags) < sizeof mntflags);
722 	 * is valid at this point in the code. Note that a call to "assert"
723 	 * is not appropriate in production code since it halts the program.
724 	 */
725 	return (mntflags);
726 }
727 
728 char	*
729 remote(char *fstype, FILE *rfp)
730 {
731 	char	buf[BUFSIZ];
732 	char	*fs;
733 	extern char *strtok();
734 
735 	if (rfp == NULL || fstype == NULL ||
736 	    strlen(fstype) > (size_t)FSTYPE_MAX)
737 		return ("");	/* not a remote */
738 	rewind(rfp);
739 	while (fgets(buf, sizeof (buf), rfp) != NULL) {
740 		fs = strtok(buf, " \t\n");
741 		if (strcmp(fstype, fs) == 0)
742 			return ("remote/");	/* is a remote fs */
743 	}
744 	return ("");	/* not a remote */
745 }
746 
747 
748 void
749 vfserror(int flag, char *special)
750 {
751 	if (special == NULL)
752 		special = "<null>";
753 	switch (flag) {
754 	case VFS_TOOLONG:
755 		fprintf(stderr,
756 gettext("%s: Warning: Line in vfstab for \"%s\" exceeds %d characters\n"),
757 		    myname, special, VFS_LINE_MAX-1);
758 		break;
759 	case VFS_TOOFEW:
760 		fprintf(stderr,
761 gettext("%s: Warning: Line for \"%s\" in vfstab has too few entries\n"),
762 		    myname, special);
763 		break;
764 	case VFS_TOOMANY:
765 		fprintf(stderr,
766 gettext("%s: Warning: Line for \"%s\" in vfstab has too many entries\n"),
767 		    myname, special);
768 		break;
769 	default:
770 		fprintf(stderr, gettext(
771 		    "%s: Warning: Error in line for \"%s\" in vfstab\n"),
772 		    myname, special);
773 	}
774 }
775 
776 void
777 mnterror(int flag)
778 {
779 	switch (flag) {
780 	case MNT_TOOLONG:
781 		fprintf(stderr,
782 		    gettext("%s: Line in mnttab exceeds %d characters\n"),
783 		    myname, MNT_LINE_MAX-2);
784 		break;
785 	case MNT_TOOFEW:
786 		fprintf(stderr,
787 		    gettext("%s: Line in mnttab has too few entries\n"),
788 		    myname);
789 		break;
790 	case MNT_TOOMANY:
791 		fprintf(stderr,
792 		    gettext("%s: Line in mnttab has too many entries\n"),
793 		    myname);
794 		break;
795 	}
796 	exit(1);
797 }
798 
799 void
800 doexec(char *fstype, char *newargv[])
801 {
802 	char	full_path[PATH_MAX];
803 	char	alter_path[PATH_MAX];
804 	char	*vfs_path = VFS_PATH;
805 	char	*alt_path = ALT_PATH;
806 	int	i;
807 
808 	/* build the full pathname of the fstype dependent command. */
809 	sprintf(full_path, "%s/%s/%s", vfs_path, fstype, myname);
810 	sprintf(alter_path, "%s/%s/%s", alt_path, fstype, myname);
811 	newargv[1] = myname;
812 
813 	if (Vflg) {
814 		printf("%s -F %s", newargv[1], fstype);
815 		for (i = 2; newargv[i]; i++)
816 			printf(" %s", newargv[i]);
817 		printf("\n");
818 		fflush(stdout);
819 		exit(0);
820 	}
821 
822 	/*
823 	 * Try to exec the fstype dependent portion of the mount.
824 	 * See if the directory is there before trying to exec dependent
825 	 * portion.  This is only useful for eliminating the
826 	 * '..mount: not found' message when '/usr' is mounted
827 	 */
828 	if (access(full_path, 0) == 0) {
829 		execv(full_path, &newargv[1]);
830 		if (errno == EACCES) {
831 			fprintf(stderr,
832 			gettext("%s: Cannot execute %s - permission denied\n"),
833 			    myname, full_path);
834 		}
835 		if (errno == ENOEXEC) {
836 			newargv[0] = "sh";
837 			newargv[1] = full_path;
838 			execv("/sbin/sh", &newargv[0]);
839 		}
840 	}
841 	execv(alter_path, &newargv[1]);
842 	if (errno == EACCES) {
843 		fprintf(stderr, gettext(
844 		    "%s: Cannot execute %s - permission denied\n"),
845 		    myname, alter_path);
846 		exit(1);
847 	}
848 	if (errno == ENOEXEC) {
849 		newargv[0] = "sh";
850 		newargv[1] = alter_path;
851 		execv("/sbin/sh", &newargv[0]);
852 	}
853 	fprintf(stderr,
854 	    gettext("%s: Operation not applicable to FSType %s\n"),
855 	    myname, fstype);
856 	exit(1);
857 }
858 
859 char *mntopts[] = { MNTOPT_IGNORE, NULL };
860 #define	IGNORE    0
861 
862 /*
863  * Return 1 if "ignore" appears in the options string
864  */
865 int
866 ignore(char *opts)
867 {
868 	char *value;
869 	char *saveptr, *my_opts;
870 	int rval = 0;
871 
872 	if (opts == NULL || *opts == NULL)
873 		return (0);
874 
875 	/*
876 	 * we make a copy of the option string to pass to getsubopt(),
877 	 * because getsubopt() modifies the string.  We also save
878 	 * the original pointer returned by strdup, because getsubopt
879 	 * changes the pointer passed into it.  If strdup fails (unlikely),
880 	 * we act as if the "ignore" option isn't set rather than fail.
881 	 */
882 
883 	if ((saveptr = my_opts = strdup(opts)) == NULL)
884 		nomem();
885 
886 	while (*my_opts != '\0') {
887 		if (getsubopt(&my_opts, mntopts, &value) == IGNORE)
888 			rval = 1;
889 	}
890 
891 	free(saveptr);
892 
893 	return (rval);
894 }
895 
896 /*
897  * Perform the parallel version of mount.  If count == 0, mount all
898  * vfstab filesystems with the automnt field == "yes".  Use fstype if
899  * supplied.  If mntlist supplied, then attempt to only mount those.
900  */
901 
902 int
903 parmount(char **mntlist, int count, char *fstype)
904 {
905 	int 		maxfd =	OPEN_MAX;
906 	struct 		rlimit rl;
907 	vfsent_t	**vl, *vp;
908 
909 	/*
910 	 * Process scaling.  After running a series
911 	 * of tests based on the number of simultaneous processes and
912 	 * processors available, optimum performance was achieved near or
913 	 * at (PROCN * 2).
914 	 */
915 	if ((maxrun = sysconf(_SC_NPROCESSORS_ONLN)) == -1)
916 		maxrun = 4;
917 	else
918 		maxrun = maxrun * 2 + 1;
919 
920 	if (getrlimit(RLIMIT_NOFILE, &rl) == 0) {
921 		rl.rlim_cur = rl.rlim_max;
922 		if (setrlimit(RLIMIT_NOFILE, &rl) == 0)
923 			maxfd = (int)rl.rlim_cur;
924 	}
925 	(void) enable_extended_FILE_stdio(-1, -1);
926 
927 	/*
928 	 * The parent needs to maintain 3 of its own fd's, plus 2 for
929 	 * each child (the stdout and stderr pipes).
930 	 */
931 	maxfd = (maxfd / 2) - 6;	/* 6 takes care of temporary  */
932 					/* periods of open fds */
933 	if (maxfd < maxrun)
934 		maxrun = maxfd;
935 	if (maxrun < 4)
936 		maxrun = 4;		/* sanity check */
937 
938 	if (count == 0)
939 		mntlist = NULL;		/* used as a flag later */
940 	else
941 		fstype = NULL;		/* mount points supplied: */
942 					/* ignore fstype */
943 	/*
944 	 * Read the whole vfstab into a linked list for quick processing.
945 	 * On average, this is the most efficient way to collect and
946 	 * manipulate the vfstab data.
947 	 */
948 	vfsll = getvfsall(fstype, mntlist == NULL);
949 
950 	/*
951 	 * Make an array out of the vfs linked list for sorting purposes.
952 	 */
953 	if (vfsll == NULL ||
954 	    (vfsarray = make_vfsarray(mntlist, count)) == NULL) {
955 		if (mntlist == NULL)	/* not an error - just none found */
956 			return (0);
957 
958 		fprintf(stderr, gettext("%s: No valid entries found in %s\n"),
959 		    myname, vfstab);
960 		return (1);
961 	}
962 
963 	/*
964 	 * Sort the entries based on their resolved path names
965 	 *
966 	 * If an lofs is encountered, then the original order of the vfstab
967 	 * file needs to be maintained until we are done mounting lofs's.
968 	 */
969 	if (!lofscnt)
970 		qsort((void *)vfsarray, vfsarraysize, sizeof (vfsent_t *),
971 		    mlevelcmp);
972 
973 	/*
974 	 * Shrink the vfsll linked list down to the new list.  This will
975 	 * speed up the pid search in cleanupkid() later.
976 	 */
977 	vfsll = vfsarray[0];
978 	for (vl = vfsarray; vp = *vl; )
979 		vp->next = *++vl;
980 
981 	/*
982 	 * Try to handle interrupts in a reasonable way.
983 	 */
984 	sigset(SIGHUP, cleanup);
985 	sigset(SIGQUIT, cleanup);
986 	sigset(SIGINT, cleanup);
987 
988 	do_mounts();		/* do the mounts */
989 
990 	if (failcnt > 0 && failcnt == lofsfail)
991 		return (ALL_LOFS_FAILURES);
992 
993 	return (exitcode);
994 }
995 
996 /*
997  * Read all vstab (fp) entries into memory if fstype == NULL.
998  * If fstype is specified, than read all those that match it.
999  *
1000  * Returns a linked list.
1001  */
1002 vfsent_t *
1003 getvfsall(char *fstype, int takeall)
1004 {
1005 	vfsent_t	*vhead, *vtail;
1006 	struct vfstab 	vget;
1007 	FILE		*fp;
1008 	int		cnt = 0, ret;
1009 
1010 	if ((fp = fopen(vfstab, "r")) == NULL) {
1011 		fprintf(stderr, gettext("%s: Cannot open %s\n"),
1012 		    myname, vfstab);
1013 		exit(1);
1014 	}
1015 
1016 	vhead = vtail = NULL;
1017 
1018 	while ((ret = getvfsent(fp, &vget)) != -1) {
1019 		vfsent_t *vp;
1020 
1021 		if (ret > 0) {
1022 			vfserror(ret, vget.vfs_mountp);
1023 			continue;
1024 		}
1025 
1026 		/*
1027 		 * If mount points were not specified, then we ignore
1028 		 * entries that aren't marked "yes".
1029 		 */
1030 		if (takeall &&
1031 		    (vget.vfs_automnt == NULL ||
1032 		    strcmp(vget.vfs_automnt, "yes")))
1033 			continue;
1034 
1035 		if (fstype && vget.vfs_fstype &&
1036 		    strcmp(fstype, vget.vfs_fstype))
1037 			continue;
1038 
1039 		if (vget.vfs_mountp == NULL ||
1040 		    (vget.vfs_fstype && (strcmp(vget.vfs_fstype, "swap") == 0)))
1041 			continue;
1042 
1043 		if (check_fields(vget.vfs_fstype, vget.vfs_mountp)) {
1044 			exitcode = 1;
1045 			continue;
1046 		}
1047 
1048 		vp = new_vfsent(&vget, cnt);	/* create new vfs entry */
1049 		if (vhead == NULL)
1050 			vhead = vp;
1051 		else
1052 			vtail->next = vp;
1053 		vtail = vp;
1054 		cnt++;
1055 	}
1056 	fclose(fp);
1057 	if (vtail == NULL) {
1058 		vfsarraysize = 0;
1059 		vfslltail = NULL;
1060 		return (NULL);
1061 	}
1062 	vtail->next = NULL;
1063 	vfslltail = vtail;	/* save it in the global variable */
1064 	vfsarraysize = cnt;
1065 	return (vhead);
1066 }
1067 
1068 
1069 /*
1070  * Returns an array of vfsent_t's based on vfsll & mntlist.
1071  */
1072 vfsent_t **
1073 make_vfsarray(char **mntlist, int count)
1074 {
1075 	vfsent_t 	*vp, *vmark, *vpprev, **vpp;
1076 	int		ndx, found;
1077 
1078 	if (vfsll == NULL)
1079 		return (NULL);
1080 
1081 	if (count > 0)
1082 		vfsarraysize = count;
1083 
1084 	vpp = (vfsent_t **)malloc(sizeof (*vpp) * (vfsarraysize + 1));
1085 	if (vpp == NULL)
1086 		nomem();
1087 
1088 	if (mntlist == NULL) {
1089 		/*
1090 		 * No mount list specified: take all vfstab mount points.
1091 		 */
1092 		for (ndx = 0, vp = vfsll; vp; vp = vp->next) {
1093 			(void) setrpath(vp);
1094 			/*
1095 			 * Sigh. lofs entries can complicate matters so much
1096 			 * that the best way to avoid problems is to
1097 			 * stop parallel mounting when an lofs is
1098 			 * encountered, so we keep a count of how many
1099 			 * there are.
1100 			 * Fortunately this is rare.
1101 			 */
1102 			if (vp->v.vfs_fstype &&
1103 			    (strcmp(vp->v.vfs_fstype, MNTTYPE_LOFS) == 0))
1104 				lofscnt++;
1105 
1106 			vpp[ndx++] = vp;
1107 		}
1108 		vpp[ndx] = NULL;
1109 		return (vpp);
1110 	}
1111 
1112 	/*
1113 	 * A list of mount points was specified on the command line
1114 	 * and we need to search for each one.
1115 	 */
1116 	vpprev = vfslltail;
1117 	vpprev->next = vfsll;	/* make a circle out of it */
1118 	vmark = vp = vfsll;
1119 	/*
1120 	 * For each specified mount point:
1121 	 */
1122 	for (ndx = 0; *mntlist; mntlist++) {
1123 		found = 0;
1124 		/*
1125 		 * Circle our entire linked list, looking for *mntlist.
1126 		 */
1127 		while (vp) {
1128 			if (strcmp(*mntlist, vp->v.vfs_mountp) == 0) {
1129 				vpp[ndx++] = vp;	/* found it. */
1130 				(void) setrpath(vp);
1131 				if (vp->v.vfs_fstype &&
1132 				    (strcmp(vp->v.vfs_fstype,
1133 				    MNTTYPE_LOFS) == 0))
1134 					lofscnt++;
1135 
1136 				if (vp == vpprev) {	/* list exhausted */
1137 					vp = NULL;
1138 					found++;
1139 					break;
1140 				}
1141 				/*
1142 				 * Remove it from the circular list.  vpprev
1143 				 * remains unchanged.
1144 				 */
1145 				vp = vp->next;
1146 				vpprev->next->next = NULL;
1147 				vpprev->next = vp;
1148 				/*
1149 				 * Set vmark to the first elem that we check
1150 				 * each time.
1151 				 */
1152 				vmark = vp;
1153 				found++;
1154 				break;
1155 			}
1156 			vpprev = vp;
1157 			vp = vp->next;
1158 			if (vp == vmark)	/* break out if we completed */
1159 						/* the circle */
1160 				break;
1161 		}
1162 
1163 		if (!found) {
1164 			fprintf(stderr, gettext(
1165 			    "%s: Warning: %s not found in %s\n"),
1166 			    myname, *mntlist, vfstab);
1167 			exitcode = 1;
1168 		}
1169 	}
1170 	if (ndx == 0)
1171 		return (NULL);
1172 
1173 	vpp[ndx] = NULL;	/* null terminate the list */
1174 	vfsarraysize = ndx;	/* adjust vfsarraysize */
1175 	return (vpp);
1176 }
1177 
1178 /*
1179  * Performs the exec argument processing, all  of the child forking and
1180  * execing, and child cleanup.
1181  * Sets exitcode to non-zero if any errors occurred.
1182  */
1183 void
1184 do_mounts(void)
1185 {
1186 	int 		i, isave, cnt;
1187 	vfsent_t 	*vp, *vpprev, **vl;
1188 	char		*newargv[ARGV_MAX];
1189 	pid_t		child;
1190 
1191 	/*
1192 	 * create the arg list once;  the only differences among
1193 	 * the calls are the options, special and mountp fields.
1194 	 */
1195 	i = 2;
1196 	if (cflg)
1197 		newargv[i++] = "-c";
1198 	if (gflg)
1199 		newargv[i++] = "-g";
1200 	if (mflg)
1201 		newargv[i++] = "-m";
1202 	if (Oflg)
1203 		newargv[i++] = "-O";
1204 	if (qflg)
1205 		newargv[i++] = "-q";
1206 	if (rflg)
1207 		newargv[i++] = "-r";
1208 	if (dashflg)
1209 		newargv[i++] = "--";
1210 	if (oflg) {
1211 		newargv[i++] = "-o";
1212 		newargv[i++] = specific_opts;
1213 	}
1214 	isave = i;
1215 
1216 	/*
1217 	 * Main loop for the mount processes
1218 	 */
1219 	vl = vfsarray;
1220 	cnt = vfsarraysize;
1221 	for (vpprev = *vl; vp = *vl; vpprev = vp, vl++, cnt--) {
1222 		/*
1223 		 * Check to see if we cross a mount level: e.g.,
1224 		 * /a/b -> /a/b/c.  If so, we need to wait for all current
1225 		 * mounts to finish, rerun realpath on the remaining mount
1226 		 * points, and resort the list.
1227 		 *
1228 		 * Also, we mount serially as long as there are lofs's
1229 		 * to mount to avoid improper mount ordering.
1230 		 */
1231 		if (vp->mlevel > vpprev->mlevel || lofscnt > 0) {
1232 			vfsent_t **vlp;
1233 
1234 			while (nrun > 0 && (dowait() != -1))
1235 				;
1236 			/*
1237 			 * Gads! It's possible for real path mounts points to
1238 			 * change after mounts are done at a lower mount
1239 			 * level.
1240 			 * Thus, we need to recalculate mount levels and
1241 			 * resort the list from this point.
1242 			 */
1243 			for (vlp = vl; *vlp; vlp++)
1244 				(void) setrpath(*vlp);
1245 			/*
1246 			 * Sort the remaining entries based on their newly
1247 			 * resolved path names.
1248 			 * Do not sort if we still have lofs's to mount.
1249 			 */
1250 			if (lofscnt == 0) {
1251 				qsort((void *)vl, cnt, sizeof (vfsent_t *),
1252 				    mlevelcmp);
1253 				vp = *vl;
1254 			}
1255 		}
1256 
1257 		if (vp->flag & VRPFAILED) {
1258 			fprintf(stderr, gettext(
1259 			    "%s: Nonexistent mount point: %s\n"),
1260 			    myname, vp->v.vfs_mountp);
1261 			vp->flag |= VNOTMOUNTED;
1262 			exitcode = 1;
1263 			continue;
1264 		}
1265 
1266 		/*
1267 		 * If mount options were not specified on the command
1268 		 * line, then use the ones found in the vfstab entry,
1269 		 * if any.
1270 		 */
1271 		i = isave;
1272 		if (!oflg && vp->v.vfs_mntopts) {
1273 			newargv[i++] = "-o";
1274 			newargv[i++] = vp->v.vfs_mntopts;
1275 		}
1276 		newargv[i++] = vp->v.vfs_special;
1277 		newargv[i++] = vp->rpath;
1278 		newargv[i] = NULL;
1279 
1280 		/*
1281 		 * This should never really fail.
1282 		 */
1283 		while (setup_iopipe(vp) == -1 && (dowait() != -1))
1284 			;
1285 
1286 		while (nrun >= maxrun && (dowait() != -1))	/* throttle */
1287 			;
1288 
1289 		if ((child = fork()) == -1) {
1290 			perror("fork");
1291 			cleanup(-1);
1292 			/* not reached */
1293 		}
1294 		if (child == 0) {		/* child */
1295 			signal(SIGHUP, SIG_IGN);
1296 			signal(SIGQUIT, SIG_IGN);
1297 			signal(SIGINT, SIG_IGN);
1298 			setup_output(vp);
1299 			doexec(vp->v.vfs_fstype, newargv);
1300 			perror("exec");
1301 			exit(1);
1302 		}
1303 
1304 		/* parent */
1305 		(void) close(vp->sopipe[WRPIPE]);
1306 		(void) close(vp->sepipe[WRPIPE]);
1307 		vp->pid = child;
1308 		nrun++;
1309 	}
1310 	/*
1311 	 * Mostly done by now - wait and clean up the stragglers.
1312 	 */
1313 	cleanup(0);
1314 }
1315 
1316 
1317 /*
1318  * Setup stdout and stderr pipes for the children's output.
1319  */
1320 int
1321 setup_iopipe(vfsent_t *mp)
1322 {
1323 	/*
1324 	 * Make a stdout and stderr pipe.  This should never fail.
1325 	 */
1326 	if (pipe(mp->sopipe) == -1)
1327 		return (-1);
1328 	if (pipe(mp->sepipe) == -1) {
1329 		(void) close(mp->sopipe[RDPIPE]);
1330 		(void) close(mp->sopipe[WRPIPE]);
1331 		return (-1);
1332 	}
1333 	/*
1334 	 * Don't block on an empty pipe.
1335 	 */
1336 	(void) fcntl(mp->sopipe[RDPIPE], F_SETFL, O_NDELAY|O_NONBLOCK);
1337 	(void) fcntl(mp->sepipe[RDPIPE], F_SETFL, O_NDELAY|O_NONBLOCK);
1338 	/*
1339 	 * Don't pass extra fds into children.
1340 	 */
1341 	(void) fcntl(mp->sopipe[RDPIPE], F_SETFD, FD_CLOEXEC);
1342 	(void) fcntl(mp->sepipe[RDPIPE], F_SETFD, FD_CLOEXEC);
1343 
1344 	return (0);
1345 }
1346 
1347 /*
1348  * Called by a child to attach its stdout and stderr to the write side of
1349  * the pipes.
1350  */
1351 void
1352 setup_output(vfsent_t *vp)
1353 {
1354 
1355 	(void) close(fileno(stdout));
1356 	(void) dup(vp->sopipe[WRPIPE]);
1357 	(void) close(vp->sopipe[WRPIPE]);
1358 
1359 	(void) close(fileno(stderr));
1360 	(void) dup(vp->sepipe[WRPIPE]);
1361 	(void) close(vp->sepipe[WRPIPE]);
1362 }
1363 
1364 /*
1365  * Parent uses this to print any stdout or stderr output issued by
1366  * the child.
1367  */
1368 static void
1369 doio(vfsent_t *vp)
1370 {
1371 	int bytes;
1372 	char ibuf[BUFSIZ];
1373 
1374 	while ((bytes = read(vp->sepipe[RDPIPE], ibuf, sizeof (ibuf))) > 0)
1375 		write(fileno(stderr), ibuf, bytes);
1376 	while ((bytes = read(vp->sopipe[RDPIPE], ibuf, sizeof (ibuf))) > 0)
1377 		write(fileno(stdout), ibuf, bytes);
1378 
1379 	(void) close(vp->sopipe[RDPIPE]);
1380 	(void) close(vp->sepipe[RDPIPE]);
1381 }
1382 
1383 /*
1384  * Waits for 1 child to die.
1385  *
1386  * Returns -1 if no children are left to wait for.
1387  * Returns 0 if a child died without an error.
1388  * Returns 1 if a child died with an error.
1389  */
1390 int
1391 dowait(void)
1392 {
1393 	int child, wstat;
1394 
1395 	if ((child = wait(&wstat)) == -1)
1396 		return (-1);
1397 	nrun--;
1398 	return (cleanupkid(child, wstat) != 0);
1399 }
1400 
1401 /*
1402  * Locates the child mount process represented by pid, outputs any io
1403  * it may have, and returns its exit code.
1404  * Sets the global exitcode if an error occurred.
1405  */
1406 int
1407 cleanupkid(pid_t pid, int wstat)
1408 {
1409 	vfsent_t *vp, *prevp;
1410 	int ret;
1411 
1412 	if (WIFEXITED(wstat))		/* this should always be true */
1413 		ret = WEXITSTATUS(wstat);
1414 	else
1415 		ret = 1;		/* assume some kind of error */
1416 	if (ret) {
1417 		exitcode = 1;
1418 		failcnt++;
1419 	}
1420 
1421 	/*
1422 	 * Find our child.
1423 	 * This search gets smaller and smaller as children are cleaned
1424 	 * up.
1425 	 */
1426 	for (prevp = NULL, vp = vfsll; vp; vp = vp->next) {
1427 		if (vp->pid != pid) {
1428 			prevp = vp;
1429 			continue;
1430 		}
1431 		/*
1432 		 * Found: let's remove it from this linked list.
1433 		 */
1434 		if (prevp) {
1435 			prevp->next = vp->next;
1436 			vp->next = NULL;
1437 		}
1438 		break;
1439 	}
1440 
1441 	if (vp == NULL) {
1442 		/*
1443 		 * This should never happen.
1444 		 */
1445 		fprintf(stderr, gettext(
1446 		    "%s: Unknown child %d\n"), myname, pid);
1447 		exitcode = 1;
1448 		return (ret);
1449 	}
1450 	doio(vp);	/* Any output? */
1451 
1452 	if (vp->v.vfs_fstype &&
1453 	    (strcmp(vp->v.vfs_fstype, MNTTYPE_LOFS) == 0)) {
1454 		lofscnt--;
1455 		if (ret)
1456 			lofsfail++;
1457 	}
1458 
1459 	vp->exitcode = ret;
1460 	return (ret);
1461 }
1462 
1463 
1464 static vfsent_t zvmount = { 0 };
1465 
1466 vfsent_t *
1467 new_vfsent(struct vfstab *vin, int order)
1468 {
1469 	vfsent_t *new;
1470 
1471 	new = (vfsent_t *)malloc(sizeof (*new));
1472 	if (new == NULL)
1473 		nomem();
1474 
1475 	*new = zvmount;
1476 	if (vin->vfs_special &&
1477 	    (new->v.vfs_special = strdup(vin->vfs_special)) == NULL)
1478 		nomem();
1479 	if (vin->vfs_mountp &&
1480 	    (new->v.vfs_mountp = strdup(vin->vfs_mountp)) == NULL)
1481 		nomem();
1482 	if (vin->vfs_fstype &&
1483 	    (new->v.vfs_fstype = strdup(vin->vfs_fstype)) == NULL)
1484 		nomem();
1485 	/*
1486 	 * If specific mount options were specified on the command
1487 	 * line, then use those.  Else, use the ones on the vfstab
1488 	 * line, if any.  In other words, specific options on the
1489 	 * command line override those in /etc/vfstab.
1490 	 */
1491 	if (oflg) {
1492 		if ((new->v.vfs_mntopts = strdup(specific_opts)) == NULL)
1493 			nomem();
1494 	} else if (vin->vfs_mntopts &&
1495 	    (new->v.vfs_mntopts = strdup(vin->vfs_mntopts)) == NULL)
1496 			nomem();
1497 
1498 	new->order = order;
1499 	return (new);
1500 }
1501 
1502 /*
1503  * Runs realpath on vp's mount point, records success or failure,
1504  * resets the mount level based on the new realpath, and returns
1505  * realpath()'s return value.
1506  */
1507 char *
1508 setrpath(vfsent_t *vp)
1509 {
1510 	char *rp;
1511 
1512 	if ((rp = realpath(vp->v.vfs_mountp, realdir)) == NULL)
1513 		vp->flag |= VRPFAILED;
1514 	else
1515 		vp->flag &= ~VRPFAILED;
1516 
1517 	if (vp->rpath)
1518 		free(vp->rpath);
1519 	if ((vp->rpath = strdup(realdir)) == NULL)
1520 		nomem();
1521 	vp->mlevel = fsgetmlevel(vp->rpath);
1522 	return (rp);
1523 }
1524 
1525 
1526 /*
1527  * sort first by mlevel (1...N), then by vfstab order.
1528  */
1529 int
1530 mlevelcmp(const void *a, const void *b)
1531 {
1532 	vfsent_t *a1, *b1;
1533 	int	lcmp;
1534 
1535 	a1 = *(vfsent_t **)a;
1536 	b1 = *(vfsent_t **)b;
1537 
1538 	lcmp = a1->mlevel - b1->mlevel;
1539 	if (lcmp == 0)
1540 		lcmp = a1->order - b1->order;
1541 	return (lcmp);
1542 }
1543 
1544 /* sort by vfstab order.  0..N */
1545 static int
1546 mordercmp(const void *a, const void *b)
1547 {
1548 	vfsent_t *a1, *b1;
1549 
1550 	a1 = *(vfsent_t **)a;
1551 	b1 = *(vfsent_t **)b;
1552 	return (a1->order - b1->order);
1553 }
1554 
1555 /*
1556  * cleanup the existing children and exit with an error
1557  * if asig != 0.
1558  */
1559 void
1560 cleanup(int asig)
1561 {
1562 	while (nrun > 0 && (dowait() != -1))
1563 		;
1564 
1565 	if (asig != 0)
1566 		exit(1);
1567 }
1568 
1569 
1570 int
1571 check_fields(char *fstype, char *mountp)
1572 {
1573 	struct stat64 stbuf;
1574 
1575 	if (strlen(fstype) > (size_t)FSTYPE_MAX) {
1576 		fprintf(stderr,
1577 		    gettext("%s: FSType %s exceeds %d characters\n"),
1578 		    myname, fstype, FSTYPE_MAX);
1579 		return (1);
1580 	}
1581 
1582 	if (mountp == NULL) {
1583 		fprintf(stderr,
1584 		    gettext("%s: Mount point cannot be determined\n"),
1585 		    myname);
1586 		return (1);
1587 	}
1588 	if (*mountp != '/') {
1589 		fprintf(stderr, gettext(
1590 		    "%s: Mount point %s is not an absolute pathname.\n"),
1591 		    myname, mountp);
1592 		return (1);
1593 	}
1594 	/*
1595 	 * Don't do some of these checks if aflg because a mount point may
1596 	 * not exist now, but will be mounted before we get to it.
1597 	 * This is one of the quirks of "secondary mounting".
1598 	 */
1599 	if (!aflg && stat64(mountp, &stbuf) < 0) {
1600 		if (errno == ENOENT || errno == ENOTDIR)
1601 			fprintf(stderr,
1602 			    gettext("%s: Mount point %s does not exist.\n"),
1603 			    myname, mountp);
1604 		else {
1605 			fprintf(stderr,
1606 			    gettext("%s: Cannot stat mount point %s.\n"),
1607 			    myname, mountp);
1608 			perror(myname);
1609 		}
1610 		return (1);
1611 	}
1612 	return (0);
1613 }
1614 
1615 void
1616 nomem(void)
1617 {
1618 	fprintf(stderr, gettext("%s: Out of memory\n"), myname);
1619 	while (nrun > 0 && (dowait() != -1))
1620 		;
1621 	exit(1);
1622 }
1623