xref: /titanic_50/usr/src/lib/libbe/common/be_mount.c (revision 72102e7461c97dc268d21d9dd8f02da45f174acd)
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 
22 /*
23  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 /*
26  * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
27  */
28 
29 /*
30  * System includes
31  */
32 #include <assert.h>
33 #include <errno.h>
34 #include <libgen.h>
35 #include <libintl.h>
36 #include <libnvpair.h>
37 #include <libzfs.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <sys/mntent.h>
42 #include <sys/mnttab.h>
43 #include <sys/mount.h>
44 #include <sys/stat.h>
45 #include <sys/types.h>
46 #include <sys/vfstab.h>
47 #include <sys/zone.h>
48 #include <sys/mkdev.h>
49 #include <unistd.h>
50 
51 #include <libbe.h>
52 #include <libbe_priv.h>
53 
54 #define	BE_TMP_MNTPNT		"/tmp/.be.XXXXXX"
55 
56 typedef struct dir_data {
57 	char *dir;
58 	char *ds;
59 } dir_data_t;
60 
61 /* Private function prototypes */
62 static int be_mount_callback(zfs_handle_t *, void *);
63 static int be_unmount_callback(zfs_handle_t *, void *);
64 static int be_get_legacy_fs_callback(zfs_handle_t *, void *);
65 static int fix_mountpoint(zfs_handle_t *);
66 static int fix_mountpoint_callback(zfs_handle_t *, void *);
67 static int get_mountpoint_from_vfstab(char *, const char *, char *, size_t,
68     boolean_t);
69 static int loopback_mount_shared_fs(zfs_handle_t *, be_mount_data_t *);
70 static int loopback_mount_zonepath(const char *, be_mount_data_t *);
71 static int iter_shared_fs_callback(zfs_handle_t *, void *);
72 static int zpool_shared_fs_callback(zpool_handle_t *, void *);
73 static int unmount_shared_fs(be_unmount_data_t *);
74 static int add_to_fs_list(be_fs_list_data_t *, const char *);
75 static int be_mount_root(zfs_handle_t *, char *);
76 static int be_unmount_root(zfs_handle_t *, be_unmount_data_t *);
77 static int be_mount_zones(zfs_handle_t *, be_mount_data_t *);
78 static int be_unmount_zones(be_unmount_data_t *);
79 static int be_mount_one_zone(zfs_handle_t *, be_mount_data_t *, char *, char *,
80     char *);
81 static int be_unmount_one_zone(be_unmount_data_t *, char *, char *, char *);
82 static int be_get_ds_from_dir_callback(zfs_handle_t *, void *);
83 
84 
85 /* ********************************************************************	*/
86 /*			Public Functions				*/
87 /* ********************************************************************	*/
88 
89 /*
90  * Function:	be_mount
91  * Description:	Mounts a BE and its subordinate datasets at a given mountpoint.
92  * Parameters:
93  *		be_attrs - pointer to nvlist_t of attributes being passed in.
94  *			The following attributes are used by this function:
95  *
96  *			BE_ATTR_ORIG_BE_NAME		*required
97  *			BE_ATTR_MOUNTPOINT		*required
98  *			BE_ATTR_MOUNT_FLAGS		*optional
99  * Return:
100  *		BE_SUCCESS - Success
101  *		be_errno_t - Failure
102  * Scope:
103  *		Public
104  */
105 int
106 be_mount(nvlist_t *be_attrs)
107 {
108 	char		*be_name = NULL;
109 	char		*mountpoint = NULL;
110 	uint16_t	flags = 0;
111 	int		ret = BE_SUCCESS;
112 
113 	/* Initialize libzfs handle */
114 	if (!be_zfs_init())
115 		return (BE_ERR_INIT);
116 
117 	/* Get original BE name */
118 	if (nvlist_lookup_string(be_attrs, BE_ATTR_ORIG_BE_NAME, &be_name)
119 	    != 0) {
120 		be_print_err(gettext("be_mount: failed to lookup "
121 		    "BE_ATTR_ORIG_BE_NAME attribute\n"));
122 		return (BE_ERR_INVAL);
123 	}
124 
125 	/* Validate original BE name */
126 	if (!be_valid_be_name(be_name)) {
127 		be_print_err(gettext("be_mount: invalid BE name %s\n"),
128 		    be_name);
129 		return (BE_ERR_INVAL);
130 	}
131 
132 	/* Get mountpoint */
133 	if (nvlist_lookup_string(be_attrs, BE_ATTR_MOUNTPOINT, &mountpoint)
134 	    != 0) {
135 		be_print_err(gettext("be_mount: failed to lookup "
136 		    "BE_ATTR_MOUNTPOINT attribute\n"));
137 		return (BE_ERR_INVAL);
138 	}
139 
140 	/* Get flags */
141 	if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
142 	    BE_ATTR_MOUNT_FLAGS, DATA_TYPE_UINT16, &flags, NULL) != 0) {
143 		be_print_err(gettext("be_mount: failed to lookup "
144 		    "BE_ATTR_MOUNT_FLAGS attribute\n"));
145 		return (BE_ERR_INVAL);
146 	}
147 
148 	ret = _be_mount(be_name, &mountpoint, flags);
149 
150 	be_zfs_fini();
151 
152 	return (ret);
153 }
154 
155 /*
156  * Function:	be_unmount
157  * Description:	Unmounts a BE and its subordinate datasets.
158  * Parameters:
159  *		be_attrs - pointer to nvlist_t of attributes being passed in.
160  *			The following attributes are used by this function:
161  *
162  *			BE_ATTR_ORIG_BE_NAME		*required
163  *			BE_ATTR_UNMOUNT_FLAGS		*optional
164  * Return:
165  *		BE_SUCCESS - Success
166  *		be_errno_t - Failure
167  * Scope:
168  *		Public
169  */
170 int
171 be_unmount(nvlist_t *be_attrs)
172 {
173 	char		*be_name = NULL;
174 	char		*be_name_mnt = NULL;
175 	char		*ds = NULL;
176 	uint16_t	flags = 0;
177 	int		ret = BE_SUCCESS;
178 
179 	/* Initialize libzfs handle */
180 	if (!be_zfs_init())
181 		return (BE_ERR_INIT);
182 
183 	/* Get original BE name */
184 	if (nvlist_lookup_string(be_attrs, BE_ATTR_ORIG_BE_NAME, &be_name)
185 	    != 0) {
186 		be_print_err(gettext("be_unmount: failed to lookup "
187 		    "BE_ATTR_ORIG_BE_NAME attribute\n"));
188 		return (BE_ERR_INVAL);
189 	}
190 
191 	/* Check if we have mountpoint argument instead of BE name */
192 	if (be_name[0] == '/') {
193 		if ((ds = be_get_ds_from_dir(be_name)) != NULL) {
194 			if ((be_name_mnt = strrchr(ds, '/')) != NULL) {
195 				free(be_name);
196 				be_name = be_name_mnt + 1;
197 			}
198 		} else {
199 			be_print_err(gettext("be_unmount: no datasets mounted "
200 			    "at '%s'\n"), be_name);
201 			return (BE_ERR_INVAL);
202 		}
203 	}
204 
205 	/* Validate original BE name */
206 	if (!be_valid_be_name(be_name)) {
207 		be_print_err(gettext("be_unmount: invalid BE name %s\n"),
208 		    be_name);
209 		return (BE_ERR_INVAL);
210 	}
211 
212 	/* Get unmount flags */
213 	if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
214 	    BE_ATTR_UNMOUNT_FLAGS, DATA_TYPE_UINT16, &flags, NULL) != 0) {
215 		be_print_err(gettext("be_unmount: failed to loookup "
216 		    "BE_ATTR_UNMOUNT_FLAGS attribute\n"));
217 		return (BE_ERR_INVAL);
218 	}
219 
220 	ret = _be_unmount(be_name, flags);
221 
222 	be_zfs_fini();
223 
224 	return (ret);
225 }
226 
227 /* ********************************************************************	*/
228 /*			Semi-Private Functions				*/
229 /* ******************************************************************** */
230 
231 /*
232  * Function:	_be_mount
233  * Description:	Mounts a BE.  If the altroot is not provided, this function
234  *		will generate a temporary mountpoint to mount the BE at.  It
235  *		will return this temporary mountpoint to the caller via the
236  *		altroot reference pointer passed in.  This returned value is
237  *		allocated on heap storage and is the repsonsibility of the
238  *		caller to free.
239  * Parameters:
240  *		be_name - pointer to name of BE to mount.
241  *		altroot - reference pointer to altroot of where to mount BE.
242  *		flags - flag indicating special handling for mounting the BE
243  * Return:
244  *		BE_SUCCESS - Success
245  *		be_errno_t - Failure
246  * Scope:
247  *		Semi-private (library wide use only)
248  */
249 int
250 _be_mount(char *be_name, char **altroot, int flags)
251 {
252 	be_transaction_data_t	bt = { 0 };
253 	be_mount_data_t	md = { 0 };
254 	zfs_handle_t	*zhp;
255 	char		obe_root_ds[MAXPATHLEN];
256 	char		*mp = NULL;
257 	char		*tmp_altroot = NULL;
258 	int		ret = BE_SUCCESS, err = 0;
259 	uuid_t		uu = { 0 };
260 	boolean_t	gen_tmp_altroot = B_FALSE;
261 
262 	if (be_name == NULL || altroot == NULL)
263 		return (BE_ERR_INVAL);
264 
265 	/* Set be_name as obe_name in bt structure */
266 	bt.obe_name = be_name;
267 
268 	/* Find which zpool obe_name lives in */
269 	if ((err = zpool_iter(g_zfs, be_find_zpool_callback, &bt)) == 0) {
270 		be_print_err(gettext("be_mount: failed to "
271 		    "find zpool for BE (%s)\n"), bt.obe_name);
272 		return (BE_ERR_BE_NOENT);
273 	} else if (err < 0) {
274 		be_print_err(gettext("be_mount: zpool_iter failed: %s\n"),
275 		    libzfs_error_description(g_zfs));
276 		return (zfs_err_to_be_err(g_zfs));
277 	}
278 
279 	/* Generate string for obe_name's root dataset */
280 	be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
281 	    sizeof (obe_root_ds));
282 	bt.obe_root_ds = obe_root_ds;
283 
284 	/* Get handle to BE's root dataset */
285 	if ((zhp = zfs_open(g_zfs, bt.obe_root_ds, ZFS_TYPE_FILESYSTEM)) ==
286 	    NULL) {
287 		be_print_err(gettext("be_mount: failed to "
288 		    "open BE root dataset (%s): %s\n"), bt.obe_root_ds,
289 		    libzfs_error_description(g_zfs));
290 		return (zfs_err_to_be_err(g_zfs));
291 	}
292 
293 	/* Make sure BE's root dataset isn't already mounted somewhere */
294 	if (zfs_is_mounted(zhp, &mp)) {
295 		ZFS_CLOSE(zhp);
296 		be_print_err(gettext("be_mount: %s is already mounted "
297 		    "at %s\n"), bt.obe_name, mp != NULL ? mp : "");
298 		free(mp);
299 		return (BE_ERR_MOUNTED);
300 	}
301 
302 	/*
303 	 * Fix this BE's mountpoint if its root dataset isn't set to
304 	 * either 'legacy' or '/'.
305 	 */
306 	if ((ret = fix_mountpoint(zhp)) != BE_SUCCESS) {
307 		be_print_err(gettext("be_mount: mountpoint check "
308 		    "failed for %s\n"), bt.obe_root_ds);
309 		ZFS_CLOSE(zhp);
310 		return (ret);
311 	}
312 
313 	/*
314 	 * If altroot not provided, create a temporary alternate root
315 	 * to mount on
316 	 */
317 	if (*altroot == NULL) {
318 		if ((ret = be_make_tmp_mountpoint(&tmp_altroot))
319 		    != BE_SUCCESS) {
320 			be_print_err(gettext("be_mount: failed to "
321 			    "make temporary mountpoint\n"));
322 			ZFS_CLOSE(zhp);
323 			return (ret);
324 		}
325 		gen_tmp_altroot = B_TRUE;
326 	} else {
327 		tmp_altroot = *altroot;
328 	}
329 
330 	md.altroot = tmp_altroot;
331 	md.shared_fs = flags & BE_MOUNT_FLAG_SHARED_FS;
332 	md.shared_rw = flags & BE_MOUNT_FLAG_SHARED_RW;
333 
334 	/* Mount the BE's root file system */
335 	if (getzoneid() == GLOBAL_ZONEID) {
336 		if ((ret = be_mount_root(zhp, tmp_altroot)) != BE_SUCCESS) {
337 			be_print_err(gettext("be_mount: failed to "
338 			    "mount BE root file system\n"));
339 			if (gen_tmp_altroot)
340 				free(tmp_altroot);
341 			ZFS_CLOSE(zhp);
342 			return (ret);
343 		}
344 	} else {
345 		/* Legacy mount the zone root dataset */
346 		if ((ret = be_mount_zone_root(zhp, &md)) != BE_SUCCESS) {
347 			be_print_err(gettext("be_mount: failed to "
348 			    "mount BE zone root file system\n"));
349 			free(md.altroot);
350 			ZFS_CLOSE(zhp);
351 			return (ret);
352 		}
353 	}
354 
355 	/* Iterate through BE's children filesystems */
356 	if ((err = zfs_iter_filesystems(zhp, be_mount_callback,
357 	    tmp_altroot)) != 0) {
358 		be_print_err(gettext("be_mount: failed to "
359 		    "mount BE (%s) on %s\n"), bt.obe_name, tmp_altroot);
360 		if (gen_tmp_altroot)
361 			free(tmp_altroot);
362 		ZFS_CLOSE(zhp);
363 		return (err);
364 	}
365 
366 	/*
367 	 * Mount shared file systems if mount flag says so.
368 	 */
369 	if (md.shared_fs) {
370 		/*
371 		 * Mount all ZFS file systems not under the BE's root dataset
372 		 */
373 		(void) zpool_iter(g_zfs, zpool_shared_fs_callback, &md);
374 
375 		/* TODO: Mount all non-ZFS file systems - Not supported yet */
376 	}
377 
378 	/*
379 	 * If we're in the global zone and the global zone has a valid uuid,
380 	 * mount all supported non-global zones.
381 	 */
382 	if (getzoneid() == GLOBAL_ZONEID &&
383 	    !(flags & BE_MOUNT_FLAG_NO_ZONES) &&
384 	    be_get_uuid(bt.obe_root_ds, &uu) == BE_SUCCESS) {
385 		if ((ret = be_mount_zones(zhp, &md)) != BE_SUCCESS) {
386 			(void) _be_unmount(bt.obe_name, 0);
387 			if (gen_tmp_altroot)
388 				free(tmp_altroot);
389 			ZFS_CLOSE(zhp);
390 			return (ret);
391 		}
392 	}
393 
394 	ZFS_CLOSE(zhp);
395 
396 	/*
397 	 * If a NULL altroot was passed in, pass the generated altroot
398 	 * back to the caller in altroot.
399 	 */
400 	if (gen_tmp_altroot)
401 		*altroot = tmp_altroot;
402 
403 	return (BE_SUCCESS);
404 }
405 
406 /*
407  * Function:	_be_unmount
408  * Description:	Unmount a BE.
409  * Parameters:
410  *		be_name - pointer to name of BE to unmount.
411  *		flags - flags for unmounting the BE.
412  * Returns:
413  *		BE_SUCCESS - Success
414  *		be_errno_t - Failure
415  * Scope:
416  *		Semi-private (library wide use only)
417  */
418 int
419 _be_unmount(char *be_name, int flags)
420 {
421 	be_transaction_data_t	bt = { 0 };
422 	be_unmount_data_t	ud = { 0 };
423 	zfs_handle_t	*zhp;
424 	uuid_t		uu = { 0 };
425 	char		obe_root_ds[MAXPATHLEN];
426 	char		mountpoint[MAXPATHLEN];
427 	char		*mp = NULL;
428 	int		ret = BE_SUCCESS;
429 	int		zret = 0;
430 
431 	if (be_name == NULL)
432 		return (BE_ERR_INVAL);
433 
434 	/* Set be_name as obe_name in bt structure */
435 	bt.obe_name = be_name;
436 
437 	/* Find which zpool obe_name lives in */
438 	if ((zret = zpool_iter(g_zfs, be_find_zpool_callback, &bt)) == 0) {
439 		be_print_err(gettext("be_unmount: failed to "
440 		    "find zpool for BE (%s)\n"), bt.obe_name);
441 		return (BE_ERR_BE_NOENT);
442 	} else if (zret < 0) {
443 		be_print_err(gettext("be_unmount: "
444 		    "zpool_iter failed: %s\n"),
445 		    libzfs_error_description(g_zfs));
446 		ret = zfs_err_to_be_err(g_zfs);
447 		return (ret);
448 	}
449 
450 	/* Generate string for obe_name's root dataset */
451 	be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
452 	    sizeof (obe_root_ds));
453 	bt.obe_root_ds = obe_root_ds;
454 
455 	/* Get handle to BE's root dataset */
456 	if ((zhp = zfs_open(g_zfs, bt.obe_root_ds, ZFS_TYPE_FILESYSTEM)) ==
457 	    NULL) {
458 		be_print_err(gettext("be_unmount: failed to "
459 		    "open BE root dataset (%s): %s\n"), bt.obe_root_ds,
460 		    libzfs_error_description(g_zfs));
461 		ret = zfs_err_to_be_err(g_zfs);
462 		return (ret);
463 	}
464 
465 	/* Make sure BE's root dataset is mounted somewhere */
466 	if (!zfs_is_mounted(zhp, &mp)) {
467 
468 		be_print_err(gettext("be_unmount: "
469 		    "(%s) not mounted\n"), bt.obe_name);
470 
471 		/*
472 		 * BE is not mounted, fix this BE's mountpoint if its root
473 		 * dataset isn't set to either 'legacy' or '/'.
474 		 */
475 		if ((ret = fix_mountpoint(zhp)) != BE_SUCCESS) {
476 			be_print_err(gettext("be_unmount: mountpoint check "
477 			    "failed for %s\n"), bt.obe_root_ds);
478 			ZFS_CLOSE(zhp);
479 			return (ret);
480 		}
481 
482 		ZFS_CLOSE(zhp);
483 		return (BE_ERR_NOTMOUNTED);
484 	}
485 
486 	/*
487 	 * If we didn't get a mountpoint from the zfs_is_mounted call,
488 	 * try and get it from its property.
489 	 */
490 	if (mp == NULL) {
491 		if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
492 		    sizeof (mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
493 			be_print_err(gettext("be_unmount: failed to "
494 			    "get mountpoint of (%s)\n"), bt.obe_name);
495 			ZFS_CLOSE(zhp);
496 			return (BE_ERR_ZFS);
497 		}
498 	} else {
499 		(void) strlcpy(mountpoint, mp, sizeof (mountpoint));
500 		free(mp);
501 	}
502 
503 	/* If BE mounted as current root, fail */
504 	if (strcmp(mountpoint, "/") == 0) {
505 		be_print_err(gettext("be_unmount: "
506 		    "cannot unmount currently running BE\n"));
507 		ZFS_CLOSE(zhp);
508 		return (BE_ERR_UMOUNT_CURR_BE);
509 	}
510 
511 	ud.altroot = mountpoint;
512 	ud.force = flags & BE_UNMOUNT_FLAG_FORCE;
513 
514 	/* Unmount all supported non-global zones if we're in the global zone */
515 	if (getzoneid() == GLOBAL_ZONEID &&
516 	    be_get_uuid(bt.obe_root_ds, &uu) == BE_SUCCESS) {
517 		if ((ret = be_unmount_zones(&ud)) != BE_SUCCESS) {
518 			ZFS_CLOSE(zhp);
519 			return (ret);
520 		}
521 	}
522 
523 	/* TODO: Unmount all non-ZFS file systems - Not supported yet */
524 
525 	/* Unmount all ZFS file systems not under the BE root dataset */
526 	if ((ret = unmount_shared_fs(&ud)) != BE_SUCCESS) {
527 		be_print_err(gettext("be_unmount: failed to "
528 		    "unmount shared file systems\n"));
529 		ZFS_CLOSE(zhp);
530 		return (ret);
531 	}
532 
533 	/* Unmount all children datasets under the BE's root dataset */
534 	if ((zret = zfs_iter_filesystems(zhp, be_unmount_callback,
535 	    &ud)) != 0) {
536 		be_print_err(gettext("be_unmount: failed to "
537 		    "unmount BE (%s)\n"), bt.obe_name);
538 		ZFS_CLOSE(zhp);
539 		return (zret);
540 	}
541 
542 	/* Unmount this BE's root filesystem */
543 	if (getzoneid() == GLOBAL_ZONEID) {
544 		if ((ret = be_unmount_root(zhp, &ud)) != BE_SUCCESS) {
545 			ZFS_CLOSE(zhp);
546 			return (ret);
547 		}
548 	} else {
549 		if ((ret = be_unmount_zone_root(zhp, &ud)) != BE_SUCCESS) {
550 			ZFS_CLOSE(zhp);
551 			return (ret);
552 		}
553 	}
554 
555 	ZFS_CLOSE(zhp);
556 
557 	return (BE_SUCCESS);
558 }
559 
560 /*
561  * Function:	be_mount_zone_root
562  * Description:	Mounts the zone root dataset for a zone.
563  * Parameters:
564  *		zfs - zfs_handle_t pointer to zone root dataset
565  *		md - be_mount_data_t pointer to data for zone to be mounted
566  * Returns:
567  *		BE_SUCCESS - Success
568  *		be_errno_t - Failure
569  * Scope:
570  *		Semi-private (library wide use only)
571  */
572 int
573 be_mount_zone_root(zfs_handle_t *zhp, be_mount_data_t *md)
574 {
575 	struct stat buf;
576 	char	mountpoint[MAXPATHLEN];
577 	int	err = 0;
578 
579 	/* Get mountpoint property of dataset */
580 	if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
581 	    sizeof (mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
582 		be_print_err(gettext("be_mount_zone_root: failed to "
583 		    "get mountpoint property for %s: %s\n"), zfs_get_name(zhp),
584 		    libzfs_error_description(g_zfs));
585 		return (zfs_err_to_be_err(g_zfs));
586 	}
587 
588 	/*
589 	 * Make sure zone's root dataset is set to 'legacy'.  This is
590 	 * currently a requirement in this implementation of zones
591 	 * support.
592 	 */
593 	if (strcmp(mountpoint, ZFS_MOUNTPOINT_LEGACY) != 0) {
594 		be_print_err(gettext("be_mount_zone_root: "
595 		    "zone root dataset mountpoint is not 'legacy'\n"));
596 		return (BE_ERR_ZONE_ROOT_NOT_LEGACY);
597 	}
598 
599 	/* Create the mountpoint if it doesn't exist */
600 	if (lstat(md->altroot, &buf) != 0) {
601 		if (mkdirp(md->altroot, 0755) != 0) {
602 			err = errno;
603 			be_print_err(gettext("be_mount_zone_root: failed "
604 			    "to create mountpoint %s\n"), md->altroot);
605 			return (errno_to_be_err(err));
606 		}
607 	}
608 
609 	/*
610 	 * Legacy mount the zone root dataset.
611 	 *
612 	 * As a workaround for 6176743, we mount the zone's root with the
613 	 * MS_OVERLAY option in case an alternate BE is mounted, and we're
614 	 * mounting the root for the zone from the current BE here.  When an
615 	 * alternate BE is mounted, it ties up the zone's zoneroot directory
616 	 * for the current BE since the zone's zonepath is loopback mounted
617 	 * from the current BE.
618 	 *
619 	 * TODO: The MS_OVERLAY option needs to be removed when 6176743
620 	 * is fixed.
621 	 */
622 	if (mount(zfs_get_name(zhp), md->altroot, MS_OVERLAY, MNTTYPE_ZFS,
623 	    NULL, 0, NULL, 0) != 0) {
624 		err = errno;
625 		be_print_err(gettext("be_mount_zone_root: failed to "
626 		    "legacy mount zone root dataset (%s) at %s\n"),
627 		    zfs_get_name(zhp), md->altroot);
628 		return (errno_to_be_err(err));
629 	}
630 
631 	return (BE_SUCCESS);
632 }
633 
634 /*
635  * Function:	be_unmount_zone_root
636  * Description:	Unmounts the zone root dataset for a zone.
637  * Parameters:
638  *		zhp - zfs_handle_t pointer to zone root dataset
639  *		ud - be_unmount_data_t pointer to data for zone to be unmounted
640  * Returns:
641  *		BE_SUCCESS - Success
642  *		be_errno_t - Failure
643  * Scope:
644  *		Semi-private (library wise use only)
645  */
646 int
647 be_unmount_zone_root(zfs_handle_t *zhp, be_unmount_data_t *ud)
648 {
649 	char	mountpoint[MAXPATHLEN];
650 
651 	/* Unmount the dataset */
652 	if (zfs_unmount(zhp, NULL, ud->force ? MS_FORCE : 0) != 0) {
653 		be_print_err(gettext("be_unmount_zone_root: failed to "
654 		    "unmount zone root dataset %s: %s\n"), zfs_get_name(zhp),
655 		    libzfs_error_description(g_zfs));
656 		return (zfs_err_to_be_err(g_zfs));
657 	}
658 
659 	/* Get the current mountpoint property for the zone root dataset */
660 	if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
661 	    sizeof (mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
662 		be_print_err(gettext("be_unmount_zone_root: failed to "
663 		    "get mountpoint property for zone root dataset (%s): %s\n"),
664 		    zfs_get_name(zhp), libzfs_error_description(g_zfs));
665 		return (zfs_err_to_be_err(g_zfs));
666 	}
667 
668 	/* If mountpoint not already set to 'legacy', set it to 'legacy' */
669 	if (strcmp(mountpoint, ZFS_MOUNTPOINT_LEGACY) != 0) {
670 		if (zfs_prop_set(zhp, zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
671 		    ZFS_MOUNTPOINT_LEGACY) != 0) {
672 			be_print_err(gettext("be_unmount_zone_root: "
673 			    "failed to set mountpoint of zone root dataset "
674 			    "%s to 'legacy': %s\n"), zfs_get_name(zhp),
675 			    libzfs_error_description(g_zfs));
676 			return (zfs_err_to_be_err(g_zfs));
677 		}
678 	}
679 
680 	return (BE_SUCCESS);
681 }
682 
683 /*
684  * Function:	be_get_legacy_fs
685  * Description:	This function iterates through all non-shared file systems
686  *		of a BE and finds the ones with a legacy mountpoint.  For
687  *		those file systems, it reads the BE's vfstab to get the
688  *		mountpoint.  If found, it adds that file system to the
689  *		be_fs_list_data_t passed in.
690  *
691  *		This function can be used to gather legacy mounted file systems
692  *		for both global BEs and non-global zone BEs.  To get data for
693  *		a non-global zone BE, the zoneroot_ds and zoneroot parameters
694  *		will be specified, otherwise they should be set to NULL.
695  * Parameters:
696  *		be_name - global BE name from which to get legacy file
697  *			system list.
698  *		be_root_ds - root dataset of global BE.
699  *		zoneroot_ds - root dataset of zone.
700  *		zoneroot - zoneroot path of zone.
701  *		fld - be_fs_list_data_t pointer.
702  * Returns:
703  *		BE_SUCCESS - Success
704  *		be_errno_t - Failure
705  * Scope:
706  *		Semi-private (library wide use only)
707  */
708 int
709 be_get_legacy_fs(char *be_name, char *be_root_ds, char *zoneroot_ds,
710     char *zoneroot, be_fs_list_data_t *fld)
711 {
712 	zfs_handle_t		*zhp = NULL;
713 	char			mountpoint[MAXPATHLEN];
714 	boolean_t		mounted_here = B_FALSE;
715 	boolean_t		zone_mounted_here = B_FALSE;
716 	int			ret = BE_SUCCESS, err = 0;
717 
718 	if (be_name == NULL || be_root_ds == NULL || fld == NULL)
719 		return (BE_ERR_INVAL);
720 
721 	/* Get handle to BE's root dataset */
722 	if ((zhp = zfs_open(g_zfs, be_root_ds, ZFS_TYPE_FILESYSTEM))
723 	    == NULL) {
724 		be_print_err(gettext("be_get_legacy_fs: failed to "
725 		    "open BE root dataset (%s): %s\n"), be_root_ds,
726 		    libzfs_error_description(g_zfs));
727 		ret = zfs_err_to_be_err(g_zfs);
728 		return (ret);
729 	}
730 
731 	/* If BE is not already mounted, mount it. */
732 	if (!zfs_is_mounted(zhp, &fld->altroot)) {
733 		if ((ret = _be_mount(be_name, &fld->altroot,
734 		    zoneroot_ds ? BE_MOUNT_FLAG_NULL :
735 		    BE_MOUNT_FLAG_NO_ZONES)) != BE_SUCCESS) {
736 			be_print_err(gettext("be_get_legacy_fs: "
737 			    "failed to mount BE %s\n"), be_name);
738 			goto cleanup;
739 		}
740 
741 		mounted_here = B_TRUE;
742 	} else if (fld->altroot == NULL) {
743 		be_print_err(gettext("be_get_legacy_fs: failed to "
744 		    "get altroot of mounted BE %s: %s\n"),
745 		    be_name, libzfs_error_description(g_zfs));
746 		ret = zfs_err_to_be_err(g_zfs);
747 		goto cleanup;
748 	}
749 
750 	/*
751 	 * If a zone root dataset was passed in, we're wanting to get
752 	 * legacy mounted file systems for that zone, not the global
753 	 * BE.
754 	 */
755 	if (zoneroot_ds != NULL) {
756 		be_mount_data_t		zone_md = { 0 };
757 
758 		/* Close off handle to global BE's root dataset */
759 		ZFS_CLOSE(zhp);
760 
761 		/* Get handle to zone's root dataset */
762 		if ((zhp = zfs_open(g_zfs, zoneroot_ds,
763 		    ZFS_TYPE_FILESYSTEM)) == NULL) {
764 			be_print_err(gettext("be_get_legacy_fs: failed to "
765 			    "open zone BE root dataset (%s): %s\n"),
766 			    zoneroot_ds, libzfs_error_description(g_zfs));
767 			ret = zfs_err_to_be_err(g_zfs);
768 			goto cleanup;
769 		}
770 
771 		/* Make sure the zone we're looking for is mounted */
772 		if (!zfs_is_mounted(zhp, &zone_md.altroot)) {
773 			char	zone_altroot[MAXPATHLEN];
774 
775 			/* Generate alternate root path for zone */
776 			(void) snprintf(zone_altroot, sizeof (zone_altroot),
777 			    "%s%s", fld->altroot, zoneroot);
778 			if ((zone_md.altroot = strdup(zone_altroot)) == NULL) {
779 				be_print_err(gettext("be_get_legacy_fs: "
780 				    "memory allocation failed\n"));
781 				ret = BE_ERR_NOMEM;
782 				goto cleanup;
783 			}
784 
785 			if ((ret = be_mount_zone_root(zhp, &zone_md))
786 			    != BE_SUCCESS) {
787 				be_print_err(gettext("be_get_legacy_fs: "
788 				    "failed to mount zone root %s\n"),
789 				    zoneroot_ds);
790 				free(zone_md.altroot);
791 				zone_md.altroot = NULL;
792 				goto cleanup;
793 			}
794 			zone_mounted_here = B_TRUE;
795 		}
796 
797 		free(fld->altroot);
798 		fld->altroot = zone_md.altroot;
799 	}
800 
801 	/*
802 	 * If the root dataset is in the vfstab with a mountpoint of "/",
803 	 * add it to the list
804 	 */
805 	if (get_mountpoint_from_vfstab(fld->altroot, zfs_get_name(zhp),
806 	    mountpoint, sizeof (mountpoint), B_FALSE) == BE_SUCCESS) {
807 		if (strcmp(mountpoint, "/") == 0) {
808 			if (add_to_fs_list(fld, zfs_get_name(zhp))
809 			    != BE_SUCCESS) {
810 				be_print_err(gettext("be_get_legacy_fs: "
811 				    "failed to add %s to fs list\n"),
812 				    zfs_get_name(zhp));
813 				ret = BE_ERR_INVAL;
814 				goto cleanup;
815 			}
816 		}
817 	}
818 
819 	/* Iterate subordinate file systems looking for legacy mounts */
820 	if ((ret = zfs_iter_filesystems(zhp, be_get_legacy_fs_callback,
821 	    fld)) != 0) {
822 		be_print_err(gettext("be_get_legacy_fs: "
823 		    "failed to iterate  %s to get legacy mounts\n"),
824 		    zfs_get_name(zhp));
825 	}
826 
827 cleanup:
828 	/* If we mounted the zone BE, unmount it */
829 	if (zone_mounted_here) {
830 		be_unmount_data_t	zone_ud = { 0 };
831 
832 		zone_ud.altroot = fld->altroot;
833 		zone_ud.force = B_TRUE;
834 		if ((err = be_unmount_zone_root(zhp, &zone_ud)) != BE_SUCCESS) {
835 			be_print_err(gettext("be_get_legacy_fs: "
836 			    "failed to unmount zone root %s\n"),
837 			    zoneroot_ds);
838 			if (ret == BE_SUCCESS)
839 				ret = err;
840 		}
841 	}
842 
843 	/* If we mounted this BE, unmount it */
844 	if (mounted_here) {
845 		if ((err = _be_unmount(be_name, 0)) != BE_SUCCESS) {
846 			be_print_err(gettext("be_get_legacy_fs: "
847 			    "failed to unmount %s\n"), be_name);
848 			if (ret == BE_SUCCESS)
849 				ret = err;
850 		}
851 	}
852 
853 	ZFS_CLOSE(zhp);
854 
855 	free(fld->altroot);
856 	fld->altroot = NULL;
857 
858 	return (ret);
859 }
860 
861 /*
862  * Function:	be_free_fs_list
863  * Description:	Function used to free the members of a be_fs_list_data_t
864  *			structure.
865  * Parameters:
866  *		fld - be_fs_list_data_t pointer to free.
867  * Returns:
868  *		None
869  * Scope:
870  *		Semi-private (library wide use only)
871  */
872 void
873 be_free_fs_list(be_fs_list_data_t *fld)
874 {
875 	int	i;
876 
877 	if (fld == NULL)
878 		return;
879 
880 	free(fld->altroot);
881 
882 	if (fld->fs_list == NULL)
883 		return;
884 
885 	for (i = 0; i < fld->fs_num; i++)
886 		free(fld->fs_list[i]);
887 
888 	free(fld->fs_list);
889 }
890 
891 /*
892  * Function:	be_get_ds_from_dir(char *dir)
893  * Description:	Given a directory path, find the underlying dataset mounted
894  *		at that directory path if there is one.   The returned name
895  *		is allocated in heap storage, so the caller is responsible
896  *		for freeing it.
897  * Parameters:
898  *		dir - char pointer of directory to find.
899  * Returns:
900  *		NULL - if directory is not mounted from a dataset.
901  *		name of dataset mounted at dir.
902  * Scope:
903  *		Semi-private (library wide use only)
904  */
905 char *
906 be_get_ds_from_dir(char *dir)
907 {
908 	dir_data_t	dd = { 0 };
909 	char		resolved_dir[MAXPATHLEN];
910 
911 	/* Make sure length of dir is within the max length */
912 	if (dir == NULL || strlen(dir) >= MAXPATHLEN)
913 		return (NULL);
914 
915 	/* Resolve dir in case its lofs mounted */
916 	(void) strlcpy(resolved_dir, dir, sizeof (resolved_dir));
917 	z_resolve_lofs(resolved_dir, sizeof (resolved_dir));
918 
919 	dd.dir = resolved_dir;
920 
921 	(void) zfs_iter_root(g_zfs, be_get_ds_from_dir_callback, &dd);
922 
923 	return (dd.ds);
924 }
925 
926 /*
927  * Function:	be_make_tmp_mountpoint
928  * Description:	This function generates a random temporary mountpoint
929  *		and creates that mountpoint directory.  It returns the
930  *		mountpoint in heap storage, so the caller is responsible
931  *		for freeing it.
932  * Parameters:
933  *		tmp_mp - reference to pointer of where to store generated
934  *			temporary mountpoint.
935  * Returns:
936  *		BE_SUCCESS - Success
937  *		be_errno_t - Failure
938  * Scope:
939  *		Semi-private (library wide use only)
940  */
941 int
942 be_make_tmp_mountpoint(char **tmp_mp)
943 {
944 	int	err = 0;
945 
946 	if ((*tmp_mp = (char *)calloc(1, sizeof (BE_TMP_MNTPNT) + 1)) == NULL) {
947 		be_print_err(gettext("be_make_tmp_mountpoint: "
948 		    "malloc failed\n"));
949 		return (BE_ERR_NOMEM);
950 	}
951 	(void) strlcpy(*tmp_mp, BE_TMP_MNTPNT, sizeof (BE_TMP_MNTPNT) + 1);
952 	if (mkdtemp(*tmp_mp) == NULL) {
953 		err = errno;
954 		be_print_err(gettext("be_make_tmp_mountpoint: mkdtemp() failed "
955 		    "for %s: %s\n"), *tmp_mp, strerror(err));
956 		free(*tmp_mp);
957 		*tmp_mp = NULL;
958 		return (errno_to_be_err(err));
959 	}
960 
961 	return (BE_SUCCESS);
962 }
963 
964 /*
965  * Function:	be_mount_pool
966  * Description: This function determines if the pool's datase is mounted
967  *		and if not it is used to mount the pool's dataset. The
968  *		function returns the current mountpoint if we are able
969  *		to mount the dataset.
970  * Parameters:
971  *		zhp - handle to the pool's dataset
972  *		tmp_mntpnt - The temporary mountpoint that the pool's
973  *			      dataset is mounted on. This is set only
974  *			      if the attempt to mount the dataset at it's
975  *			      set mountpoint fails, and we've used a
976  *			      temporary mount point for this dataset. It
977  *			      is expected that the caller will free this
978  *			      memory.
979  *		orig_mntpnt - The original mountpoint for the pool. If a
980  *			      temporary mount point was needed this will
981  *			      be used to reset the mountpoint property to
982  *			      it's original mountpoint. It is expected that
983  *			      the caller will free this memory.
984  *		pool_mounted - This flag indicates that the pool was mounted
985  *			       in this function.
986  * Returns:
987  *		BE_SUCCESS - Success
988  *		be_errno_t - Failure
989  * Scope:
990  *		Semi-private (library wide use only)
991  */
992 int
993 be_mount_pool(
994 	zfs_handle_t *zhp,
995 	char **tmp_mntpnt,
996 	char **orig_mntpnt,
997 	boolean_t *pool_mounted)
998 {
999 
1000 	char		mountpoint[MAXPATHLEN];
1001 	int		ret = 0;
1002 
1003 	*tmp_mntpnt = NULL;
1004 	*orig_mntpnt = NULL;
1005 	*pool_mounted = B_FALSE;
1006 
1007 	if (!zfs_is_mounted(zhp, NULL)) {
1008 		if (zfs_mount(zhp, NULL, 0) != 0) {
1009 			if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
1010 			    sizeof (mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
1011 				be_print_err(gettext("be_mount_pool: failed to "
1012 				    "get mountpoint of (%s): %s\n"),
1013 				    zfs_get_name(zhp),
1014 				    libzfs_error_description(g_zfs));
1015 				return (zfs_err_to_be_err(g_zfs));
1016 			}
1017 			if ((*orig_mntpnt = strdup(mountpoint)) == NULL) {
1018 				be_print_err(gettext("be_mount_pool: memory "
1019 				    "allocation failed\n"));
1020 				return (BE_ERR_NOMEM);
1021 			}
1022 			/*
1023 			 * attempt to mount on a temp mountpoint
1024 			 */
1025 			if ((ret = be_make_tmp_mountpoint(tmp_mntpnt))
1026 			    != BE_SUCCESS) {
1027 				be_print_err(gettext("be_mount_pool: failed "
1028 				    "to make temporary mountpoint\n"));
1029 				free(*orig_mntpnt);
1030 				*orig_mntpnt = NULL;
1031 				return (ret);
1032 			}
1033 
1034 			if (zfs_prop_set(zhp,
1035 			    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
1036 			    *tmp_mntpnt) != 0) {
1037 				be_print_err(gettext("be_mount_pool: failed "
1038 				    "to set mountpoint of pool dataset %s to "
1039 				    "%s: %s\n"), zfs_get_name(zhp),
1040 				    *orig_mntpnt,
1041 				    libzfs_error_description(g_zfs));
1042 				free(*tmp_mntpnt);
1043 				free(*orig_mntpnt);
1044 				*orig_mntpnt = NULL;
1045 				*tmp_mntpnt = NULL;
1046 				return (zfs_err_to_be_err(g_zfs));
1047 			}
1048 
1049 			if (zfs_mount(zhp, NULL, 0) != 0) {
1050 				be_print_err(gettext("be_mount_pool: failed "
1051 				    "to mount dataset %s at %s: %s\n"),
1052 				    zfs_get_name(zhp), *tmp_mntpnt,
1053 				    libzfs_error_description(g_zfs));
1054 				ret = zfs_err_to_be_err(g_zfs);
1055 				if (zfs_prop_set(zhp,
1056 				    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
1057 				    mountpoint) != 0) {
1058 					be_print_err(gettext("be_mount_pool: "
1059 					    "failed to set mountpoint of pool "
1060 					    "dataset %s to %s: %s\n"),
1061 					    zfs_get_name(zhp), *tmp_mntpnt,
1062 					    libzfs_error_description(g_zfs));
1063 				}
1064 				free(*tmp_mntpnt);
1065 				free(*orig_mntpnt);
1066 				*orig_mntpnt = NULL;
1067 				*tmp_mntpnt = NULL;
1068 				return (ret);
1069 			}
1070 		}
1071 		*pool_mounted = B_TRUE;
1072 	}
1073 
1074 	return (BE_SUCCESS);
1075 }
1076 
1077 /*
1078  * Function:	be_unmount_pool
1079  * Description: This function is used to unmount the pool's dataset if we
1080  *		mounted it previously using be_mount_pool().
1081  * Parameters:
1082  *		zhp - handle to the pool's dataset
1083  *		tmp_mntpnt - If a temprary mount point was used this will
1084  *			     be set. Since this was created in be_mount_pool
1085  *			     we will need to clean it up here.
1086  *		orig_mntpnt - The original mountpoint for the pool. This is
1087  *			      used to set the dataset mountpoint property
1088  *			      back to it's original value in the case where a
1089  *			      temporary mountpoint was used.
1090  * Returns:
1091  *		BE_SUCCESS - Success
1092  *		be_errno_t - Failure
1093  * Scope:
1094  *		Semi-private (library wide use only)
1095  */
1096 int
1097 be_unmount_pool(
1098 	zfs_handle_t *zhp,
1099 	char *tmp_mntpnt,
1100 	char *orig_mntpnt)
1101 {
1102 	if (zfs_unmount(zhp, NULL, 0) != 0) {
1103 		be_print_err(gettext("be_unmount_pool: failed to "
1104 		    "unmount pool (%s): %s\n"), zfs_get_name(zhp),
1105 		    libzfs_error_description(g_zfs));
1106 		return (zfs_err_to_be_err(g_zfs));
1107 	}
1108 	if (orig_mntpnt != NULL) {
1109 		if (tmp_mntpnt != NULL &&
1110 		    strcmp(orig_mntpnt, tmp_mntpnt) != 0) {
1111 			(void) rmdir(tmp_mntpnt);
1112 		}
1113 		if (zfs_prop_set(zhp,
1114 		    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
1115 		    orig_mntpnt) != 0) {
1116 			be_print_err(gettext("be_unmount_pool: failed "
1117 			    "to set the mountpoint for dataset (%s) to "
1118 			    "%s: %s\n"), zfs_get_name(zhp), orig_mntpnt,
1119 			    libzfs_error_description(g_zfs));
1120 			return (zfs_err_to_be_err(g_zfs));
1121 		}
1122 	}
1123 
1124 	return (BE_SUCCESS);
1125 }
1126 
1127 /* ********************************************************************	*/
1128 /*			Private Functions				*/
1129 /* ********************************************************************	*/
1130 
1131 /*
1132  * Function:	be_mount_callback
1133  * Description:	Callback function used to iterate through all of a BE's
1134  *		subordinate file systems and to mount them accordingly.
1135  * Parameters:
1136  *		zhp - zfs_handle_t pointer to current file system being
1137  *			processed.
1138  *		data - pointer to the altroot of where to mount BE.
1139  * Returns:
1140  *		0 - Success
1141  *		be_errno_t - Failure
1142  * Scope:
1143  *		Private
1144  */
1145 static int
1146 be_mount_callback(zfs_handle_t *zhp, void *data)
1147 {
1148 	zprop_source_t	sourcetype;
1149 	const char	*fs_name = zfs_get_name(zhp);
1150 	char		source[ZFS_MAXNAMELEN];
1151 	char		*altroot = data;
1152 	char		zhp_mountpoint[MAXPATHLEN];
1153 	char		mountpoint[MAXPATHLEN];
1154 	int		ret = 0;
1155 
1156 	/* Get dataset's mountpoint and source values */
1157 	if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, zhp_mountpoint,
1158 	    sizeof (zhp_mountpoint), &sourcetype, source, sizeof (source),
1159 	    B_FALSE) != 0) {
1160 		be_print_err(gettext("be_mount_callback: failed to "
1161 		    "get mountpoint and sourcetype for %s\n"),
1162 		    fs_name);
1163 		ZFS_CLOSE(zhp);
1164 		return (BE_ERR_ZFS);
1165 	}
1166 
1167 	/*
1168 	 * Set this filesystem's 'canmount' property to 'noauto' just incase
1169 	 * it's been set 'on'.  We do this so that when we change its
1170 	 * mountpoint zfs won't immediately try to mount it.
1171 	 */
1172 	if (zfs_prop_set(zhp, zfs_prop_to_name(ZFS_PROP_CANMOUNT), "noauto")) {
1173 		be_print_err(gettext("be_mount_callback: failed to "
1174 		    "set canmount to 'noauto' (%s)\n"), fs_name);
1175 		ZFS_CLOSE(zhp);
1176 		return (BE_ERR_ZFS);
1177 	}
1178 
1179 	/*
1180 	 * If the mountpoint is none, there's nothing to do, goto next.
1181 	 * If the mountpoint is legacy, legacy mount it with mount(2).
1182 	 * If the mountpoint is inherited, its mountpoint should
1183 	 * already be set.  If it's not, then explicitly fix-up
1184 	 * the mountpoint now by appending its explicitly set
1185 	 * mountpoint value to the BE mountpoint.
1186 	 */
1187 	if (strcmp(zhp_mountpoint, ZFS_MOUNTPOINT_NONE) == 0) {
1188 		goto next;
1189 	} else if (strcmp(zhp_mountpoint, ZFS_MOUNTPOINT_LEGACY) == 0) {
1190 		/*
1191 		 * If the mountpoint is set to 'legacy', we need to
1192 		 * dig into this BE's vfstab to figure out where to
1193 		 * mount it, and just mount it via mount(2).
1194 		 */
1195 		if (get_mountpoint_from_vfstab(altroot, fs_name,
1196 		    mountpoint, sizeof (mountpoint), B_TRUE) == BE_SUCCESS) {
1197 
1198 			/* Legacy mount the file system */
1199 			if (mount(fs_name, mountpoint, MS_DATA,
1200 			    MNTTYPE_ZFS, NULL, 0, NULL, 0) != 0) {
1201 				be_print_err(
1202 				    gettext("be_mount_callback: "
1203 				    "failed to mount %s on %s\n"),
1204 				    fs_name, mountpoint);
1205 			}
1206 		} else {
1207 			be_print_err(
1208 			    gettext("be_mount_callback: "
1209 			    "no entry for %s in vfstab, "
1210 			    "skipping ...\n"), fs_name);
1211 		}
1212 
1213 		goto next;
1214 
1215 	} else if (sourcetype & ZPROP_SRC_INHERITED) {
1216 		/*
1217 		 * If the mountpoint is inherited, its parent should have
1218 		 * already been processed so its current mountpoint value
1219 		 * is what its mountpoint ought to be.
1220 		 */
1221 		(void) strlcpy(mountpoint, zhp_mountpoint, sizeof (mountpoint));
1222 	} else if (sourcetype & ZPROP_SRC_LOCAL) {
1223 		/*
1224 		 * Else process dataset with explicitly set mountpoint.
1225 		 */
1226 		(void) snprintf(mountpoint, sizeof (mountpoint),
1227 		    "%s%s", altroot, zhp_mountpoint);
1228 
1229 		/* Set the new mountpoint for the dataset */
1230 		if (zfs_prop_set(zhp,
1231 		    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
1232 		    mountpoint)) {
1233 			be_print_err(gettext("be_mount_callback: "
1234 			    "failed to set mountpoint for %s to "
1235 			    "%s\n"), fs_name, mountpoint);
1236 			ZFS_CLOSE(zhp);
1237 			return (BE_ERR_ZFS);
1238 		}
1239 	} else {
1240 		be_print_err(gettext("be_mount_callback: "
1241 		    "mountpoint sourcetype of %s is %d, skipping ...\n"),
1242 		    fs_name, sourcetype);
1243 
1244 		goto next;
1245 	}
1246 
1247 	/* Mount this filesystem */
1248 	if (zfs_mount(zhp, NULL, 0) != 0) {
1249 		be_print_err(gettext("be_mount_callback: failed to "
1250 		    "mount dataset %s at %s: %s\n"), fs_name, mountpoint,
1251 		    libzfs_error_description(g_zfs));
1252 		/*
1253 		 * Set this filesystem's 'mountpoint' property back to what
1254 		 * it was
1255 		 */
1256 		if (sourcetype & ZPROP_SRC_LOCAL &&
1257 		    strcmp(zhp_mountpoint, ZFS_MOUNTPOINT_LEGACY) != 0) {
1258 			(void) zfs_prop_set(zhp,
1259 			    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
1260 			    zhp_mountpoint);
1261 		}
1262 
1263 		ZFS_CLOSE(zhp);
1264 		return (BE_ERR_MOUNT);
1265 	}
1266 
1267 next:
1268 	/* Iterate through this dataset's children and mount them */
1269 	if ((ret = zfs_iter_filesystems(zhp, be_mount_callback,
1270 	    altroot)) != 0) {
1271 		ZFS_CLOSE(zhp);
1272 		return (ret);
1273 	}
1274 
1275 
1276 	ZFS_CLOSE(zhp);
1277 	return (0);
1278 }
1279 
1280 /*
1281  * Function:	be_unmount_callback
1282  * Description:	Callback function used to iterate through all of a BE's
1283  *		subordinate file systems and to unmount them.
1284  * Parameters:
1285  *		zhp - zfs_handle_t pointer to current file system being
1286  *			processed.
1287  *		data - pointer to the mountpoint of where BE is mounted.
1288  * Returns:
1289  *		0 - Success
1290  *		be_errno_t - Failure
1291  * Scope:
1292  *		Private
1293  */
1294 static int
1295 be_unmount_callback(zfs_handle_t *zhp, void *data)
1296 {
1297 	be_unmount_data_t	*ud = data;
1298 	zprop_source_t	sourcetype;
1299 	const char	*fs_name = zfs_get_name(zhp);
1300 	char		source[ZFS_MAXNAMELEN];
1301 	char		mountpoint[MAXPATHLEN];
1302 	char		*zhp_mountpoint;
1303 	int		ret = 0;
1304 
1305 	/* Iterate down this dataset's children first */
1306 	if (zfs_iter_filesystems(zhp, be_unmount_callback, ud)) {
1307 		ret = BE_ERR_UMOUNT;
1308 		goto done;
1309 	}
1310 
1311 	/* Is dataset even mounted ? */
1312 	if (!zfs_is_mounted(zhp, NULL))
1313 		goto done;
1314 
1315 	/* Unmount this file system */
1316 	if (zfs_unmount(zhp, NULL, ud->force ? MS_FORCE : 0) != 0) {
1317 		be_print_err(gettext("be_unmount_callback: "
1318 		    "failed to unmount %s: %s\n"), fs_name,
1319 		    libzfs_error_description(g_zfs));
1320 		ret = zfs_err_to_be_err(g_zfs);
1321 		goto done;
1322 	}
1323 
1324 	/* Get dataset's current mountpoint and source value */
1325 	if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
1326 	    sizeof (mountpoint), &sourcetype, source, sizeof (source),
1327 	    B_FALSE) != 0) {
1328 		be_print_err(gettext("be_unmount_callback: "
1329 		    "failed to get mountpoint and sourcetype for %s: %s\n"),
1330 		    fs_name, libzfs_error_description(g_zfs));
1331 		ret = zfs_err_to_be_err(g_zfs);
1332 		goto done;
1333 	}
1334 
1335 	if (sourcetype & ZPROP_SRC_INHERITED) {
1336 		/*
1337 		 * If the mountpoint is inherited we don't need to
1338 		 * do anything.  When its parent gets processed
1339 		 * its mountpoint will be set accordingly.
1340 		 */
1341 		goto done;
1342 	} else if (sourcetype & ZPROP_SRC_LOCAL) {
1343 
1344 		if (strcmp(mountpoint, ZFS_MOUNTPOINT_LEGACY) == 0) {
1345 			/*
1346 			 * If the mountpoint is set to 'legacy', its already
1347 			 * been unmounted (from above call to zfs_unmount), and
1348 			 * we don't need to do anything else with it.
1349 			 */
1350 			goto done;
1351 
1352 		} else {
1353 			/*
1354 			 * Else process dataset with explicitly set mountpoint.
1355 			 */
1356 
1357 			/*
1358 			 * Get this dataset's mountpoint relative to
1359 			 * the BE's mountpoint.
1360 			 */
1361 			if ((strncmp(mountpoint, ud->altroot,
1362 			    strlen(ud->altroot)) == 0) &&
1363 			    (mountpoint[strlen(ud->altroot)] == '/')) {
1364 
1365 				zhp_mountpoint = mountpoint +
1366 				    strlen(ud->altroot);
1367 
1368 				/* Set this dataset's mountpoint value */
1369 				if (zfs_prop_set(zhp,
1370 				    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
1371 				    zhp_mountpoint)) {
1372 					be_print_err(
1373 					    gettext("be_unmount_callback: "
1374 					    "failed to set mountpoint for "
1375 					    "%s to %s: %s\n"), fs_name,
1376 					    zhp_mountpoint,
1377 					    libzfs_error_description(g_zfs));
1378 					ret = zfs_err_to_be_err(g_zfs);
1379 				}
1380 			} else {
1381 				be_print_err(
1382 				    gettext("be_unmount_callback: "
1383 				    "%s not mounted under BE's altroot %s, "
1384 				    "skipping ...\n"), fs_name, ud->altroot);
1385 				/*
1386 				 * fs_name is mounted but not under the
1387 				 * root for this BE.
1388 				 */
1389 				ret = BE_ERR_INVALMOUNTPOINT;
1390 			}
1391 		}
1392 	} else {
1393 		be_print_err(gettext("be_unmount_callback: "
1394 		    "mountpoint sourcetype of %s is %d, skipping ...\n"),
1395 		    fs_name, sourcetype);
1396 		ret = BE_ERR_ZFS;
1397 	}
1398 
1399 done:
1400 	/* Set this filesystem's 'canmount' property to 'noauto' */
1401 	if (zfs_prop_set(zhp, zfs_prop_to_name(ZFS_PROP_CANMOUNT), "noauto")) {
1402 		be_print_err(gettext("be_unmount_callback: "
1403 		    "failed to set canmount to 'noauto' (%s)\n"), fs_name);
1404 		if (ret == 0)
1405 			ret = BE_ERR_ZFS;
1406 	}
1407 
1408 	ZFS_CLOSE(zhp);
1409 	return (ret);
1410 }
1411 
1412 /*
1413  * Function:	be_get_legacy_fs_callback
1414  * Description:	The callback function is used to iterate through all
1415  *		non-shared file systems of a BE, finding ones that have
1416  *		a legacy mountpoint and an entry in the BE's vfstab.
1417  *		It adds these file systems to the callback data.
1418  * Parameters:
1419  *		zhp - zfs_handle_t pointer to current file system being
1420  *			processed.
1421  *		data - be_fs_list_data_t pointer
1422  * Returns:
1423  *		0 - Success
1424  *		be_errno_t - Failure
1425  * Scope:
1426  *		Private
1427  */
1428 static int
1429 be_get_legacy_fs_callback(zfs_handle_t *zhp, void *data)
1430 {
1431 	be_fs_list_data_t	*fld = data;
1432 	const char		*fs_name = zfs_get_name(zhp);
1433 	char			zhp_mountpoint[MAXPATHLEN];
1434 	char			mountpoint[MAXPATHLEN];
1435 	int			ret = 0;
1436 
1437 	/* Get this dataset's mountpoint property */
1438 	if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, zhp_mountpoint,
1439 	    sizeof (zhp_mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
1440 		be_print_err(gettext("be_get_legacy_fs_callback: "
1441 		    "failed to get mountpoint for %s: %s\n"),
1442 		    fs_name, libzfs_error_description(g_zfs));
1443 		ret = zfs_err_to_be_err(g_zfs);
1444 		ZFS_CLOSE(zhp);
1445 		return (ret);
1446 	}
1447 
1448 	/*
1449 	 * If mountpoint is legacy, try to get its mountpoint from this BE's
1450 	 * vfstab.  If it exists in the vfstab, add this file system to the
1451 	 * callback data.
1452 	 */
1453 	if (strcmp(zhp_mountpoint, ZFS_MOUNTPOINT_LEGACY) == 0) {
1454 		if (get_mountpoint_from_vfstab(fld->altroot, fs_name,
1455 		    mountpoint, sizeof (mountpoint), B_FALSE) != BE_SUCCESS) {
1456 			be_print_err(gettext("be_get_legacy_fs_callback: "
1457 			    "no entry for %s in vfstab, "
1458 			    "skipping ...\n"), fs_name);
1459 
1460 			goto next;
1461 		}
1462 
1463 		/* Record file system into the callback data. */
1464 		if (add_to_fs_list(fld, zfs_get_name(zhp)) != BE_SUCCESS) {
1465 			be_print_err(gettext("be_get_legacy_fs_callback: "
1466 			    "failed to add %s to fs list\n"), mountpoint);
1467 			ZFS_CLOSE(zhp);
1468 			return (BE_ERR_NOMEM);
1469 		}
1470 	}
1471 
1472 next:
1473 	/* Iterate through this dataset's children file systems */
1474 	if ((ret = zfs_iter_filesystems(zhp, be_get_legacy_fs_callback,
1475 	    fld)) != 0) {
1476 		ZFS_CLOSE(zhp);
1477 		return (ret);
1478 	}
1479 	ZFS_CLOSE(zhp);
1480 	return (0);
1481 }
1482 
1483 /*
1484  * Function:	add_to_fs_list
1485  * Description:	Function used to add a file system to the fs_list array in
1486  *			a be_fs_list_data_t structure.
1487  * Parameters:
1488  *		fld - be_fs_list_data_t pointer
1489  *		fs - file system to add
1490  * Returns:
1491  *		BE_SUCCESS - Success
1492  *		1 - Failure
1493  * Scope:
1494  *		Private
1495  */
1496 static int
1497 add_to_fs_list(be_fs_list_data_t *fld, const char *fs)
1498 {
1499 	if (fld == NULL || fs == NULL)
1500 		return (1);
1501 
1502 	if ((fld->fs_list = (char **)realloc(fld->fs_list,
1503 	    sizeof (char *)*(fld->fs_num + 1))) == NULL) {
1504 		be_print_err(gettext("add_to_fs_list: "
1505 		    "memory allocation failed\n"));
1506 		return (1);
1507 	}
1508 
1509 	if ((fld->fs_list[fld->fs_num++] = strdup(fs)) == NULL) {
1510 		be_print_err(gettext("add_to_fs_list: "
1511 		    "memory allocation failed\n"));
1512 		return (1);
1513 	}
1514 
1515 	return (BE_SUCCESS);
1516 }
1517 
1518 /*
1519  * Function:	zpool_shared_fs_callback
1520  * Description:	Callback function used to iterate through all existing pools
1521  *		to find and mount all shared filesystems.  This function
1522  *		processes the pool's "pool data" dataset, then uses
1523  *		iter_shared_fs_callback to iterate through the pool's
1524  *		datasets.
1525  * Parameters:
1526  *		zlp - zpool_handle_t pointer to the current pool being
1527  *			looked at.
1528  *		data - be_mount_data_t pointer
1529  * Returns:
1530  *		0 - Success
1531  *		be_errno_t - Failure
1532  * Scope:
1533  *		Private
1534  */
1535 static int
1536 zpool_shared_fs_callback(zpool_handle_t *zlp, void *data)
1537 {
1538 	be_mount_data_t	*md = data;
1539 	zfs_handle_t	*zhp = NULL;
1540 	const char	*zpool = zpool_get_name(zlp);
1541 	int		ret = 0;
1542 
1543 	/*
1544 	 * Get handle to pool's "pool data" dataset
1545 	 */
1546 	if ((zhp = zfs_open(g_zfs, zpool, ZFS_TYPE_FILESYSTEM)) == NULL) {
1547 		be_print_err(gettext("zpool_shared_fs: "
1548 		    "failed to open pool dataset %s: %s\n"), zpool,
1549 		    libzfs_error_description(g_zfs));
1550 		ret = zfs_err_to_be_err(g_zfs);
1551 		zpool_close(zlp);
1552 		return (ret);
1553 	}
1554 
1555 	/* Process this pool's "pool data" dataset */
1556 	(void) loopback_mount_shared_fs(zhp, md);
1557 
1558 	/* Interate through this pool's children */
1559 	(void) zfs_iter_filesystems(zhp, iter_shared_fs_callback, md);
1560 
1561 	ZFS_CLOSE(zhp);
1562 	zpool_close(zlp);
1563 
1564 	return (0);
1565 }
1566 
1567 /*
1568  * Function:	iter_shared_fs_callback
1569  * Description:	Callback function used to iterate through a pool's datasets
1570  *		to find and mount all shared filesystems.  It makes sure to
1571  *		find the BE container dataset of the pool, if it exists, and
1572  *		does not process and iterate down that path.
1573  *
1574  *		Note - This function iterates linearly down the
1575  *		hierarchical dataset paths and mounts things as it goes
1576  *		along.  It does not make sure that something deeper down
1577  *		a dataset path has an interim mountpoint for something
1578  *		processed earlier.
1579  *
1580  * Parameters:
1581  *		zhp - zfs_handle_t pointer to the current dataset being
1582  *			processed.
1583  *		data - be_mount_data_t pointer
1584  * Returns:
1585  *		0 - Success
1586  *		be_errno_t - Failure
1587  * Scope:
1588  *		Private
1589  */
1590 static int
1591 iter_shared_fs_callback(zfs_handle_t *zhp, void *data)
1592 {
1593 	be_mount_data_t	*md = data;
1594 	const char	*name = zfs_get_name(zhp);
1595 	char		container_ds[MAXPATHLEN];
1596 	char		tmp_name[MAXPATHLEN];
1597 	char		*pool;
1598 
1599 	/* Get the pool's name */
1600 	(void) strlcpy(tmp_name, name, sizeof (tmp_name));
1601 	pool = strtok(tmp_name, "/");
1602 
1603 	if (pool) {
1604 		/* Get the name of this pool's container dataset */
1605 		be_make_container_ds(pool, container_ds,
1606 		    sizeof (container_ds));
1607 
1608 		/*
1609 		 * If what we're processing is this pool's BE container
1610 		 * dataset, skip it.
1611 		 */
1612 		if (strcmp(name, container_ds) == 0) {
1613 			ZFS_CLOSE(zhp);
1614 			return (0);
1615 		}
1616 	} else {
1617 		/* Getting the pool name failed, return error */
1618 		be_print_err(gettext("iter_shared_fs_callback: "
1619 		    "failed to get pool name from %s\n"), name);
1620 		ZFS_CLOSE(zhp);
1621 		return (BE_ERR_POOL_NOENT);
1622 	}
1623 
1624 	/* Mount this shared filesystem */
1625 	(void) loopback_mount_shared_fs(zhp, md);
1626 
1627 	/* Iterate this dataset's children file systems */
1628 	(void) zfs_iter_filesystems(zhp, iter_shared_fs_callback, md);
1629 	ZFS_CLOSE(zhp);
1630 
1631 	return (0);
1632 }
1633 
1634 /*
1635  * Function:	loopback_mount_shared_fs
1636  * Description:	This function loopback mounts a file system into the altroot
1637  *		area of the BE being mounted.  Since these are shared file
1638  *		systems, they are expected to be already mounted for the
1639  *		current BE, and this function just loopback mounts them into
1640  *		the BE mountpoint.  If they are not mounted for the current
1641  *		live system, they are skipped and not mounted into the BE
1642  *		we're mounting.
1643  * Parameters:
1644  *		zhp - zfs_handle_t pointer to the dataset to loopback mount
1645  *		md - be_mount_data_t pointer
1646  * Returns:
1647  *		BE_SUCCESS - Success
1648  *		be_errno_t - Failure
1649  * Scope:
1650  *		Private
1651  */
1652 static int
1653 loopback_mount_shared_fs(zfs_handle_t *zhp, be_mount_data_t *md)
1654 {
1655 	char		zhp_mountpoint[MAXPATHLEN];
1656 	char		mountpoint[MAXPATHLEN];
1657 	char		*mp = NULL;
1658 	char		optstr[MAX_MNTOPT_STR];
1659 	int		mflag = MS_OPTIONSTR;
1660 	int		err;
1661 
1662 	/*
1663 	 * Check if file system is currently mounted and not delegated
1664 	 * to a non-global zone (if we're in the global zone)
1665 	 */
1666 	if (zfs_is_mounted(zhp, &mp) && (getzoneid() != GLOBAL_ZONEID ||
1667 	    !zfs_prop_get_int(zhp, ZFS_PROP_ZONED))) {
1668 		/*
1669 		 * If we didn't get a mountpoint from the zfs_is_mounted call,
1670 		 * get it from the mountpoint property.
1671 		 */
1672 		if (mp == NULL) {
1673 			if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT,
1674 			    zhp_mountpoint, sizeof (zhp_mountpoint), NULL,
1675 			    NULL, 0, B_FALSE) != 0) {
1676 				be_print_err(
1677 				    gettext("loopback_mount_shared_fs: "
1678 				    "failed to get mountpoint property\n"));
1679 				return (BE_ERR_ZFS);
1680 			}
1681 		} else {
1682 			(void) strlcpy(zhp_mountpoint, mp,
1683 			    sizeof (zhp_mountpoint));
1684 			free(mp);
1685 		}
1686 
1687 		(void) snprintf(mountpoint, sizeof (mountpoint), "%s%s",
1688 		    md->altroot, zhp_mountpoint);
1689 
1690 		/* Mount it read-only if read-write was not requested */
1691 		if (!md->shared_rw) {
1692 			mflag |= MS_RDONLY;
1693 		}
1694 
1695 		/* Add the "nosub" option to the mount options string */
1696 		(void) strlcpy(optstr, MNTOPT_NOSUB, sizeof (optstr));
1697 
1698 		/* Loopback mount this dataset at the altroot */
1699 		if (mount(zhp_mountpoint, mountpoint, mflag, MNTTYPE_LOFS,
1700 		    NULL, 0, optstr, sizeof (optstr)) != 0) {
1701 			err = errno;
1702 			be_print_err(gettext("loopback_mount_shared_fs: "
1703 			    "failed to loopback mount %s at %s: %s\n"),
1704 			    zhp_mountpoint, mountpoint, strerror(err));
1705 			return (BE_ERR_MOUNT);
1706 		}
1707 	}
1708 
1709 	return (BE_SUCCESS);
1710 }
1711 
1712 /*
1713  * Function:	loopback_mount_zonepath
1714  * Description:	This function loopback mounts a zonepath into the altroot
1715  *		area of the BE being mounted.  Since these are shared file
1716  *		systems, they are expected to be already mounted for the
1717  *		current BE, and this function just loopback mounts them into
1718  *		the BE mountpoint.
1719  * Parameters:
1720  *		zonepath - pointer to zone path in the current BE
1721  *		md - be_mount_data_t pointer
1722  * Returns:
1723  *		BE_SUCCESS - Success
1724  *		be_errno_t - Failure
1725  * Scope:
1726  *		Private
1727  */
1728 static int
1729 loopback_mount_zonepath(const char *zonepath, be_mount_data_t *md)
1730 {
1731 	FILE		*fp = (FILE *)NULL;
1732 	struct stat	st;
1733 	char		*p;
1734 	char		*p1;
1735 	char		*parent_dir;
1736 	struct extmnttab	extmtab;
1737 	dev_t		dev = NODEV;
1738 	char		*parentmnt;
1739 	char		alt_parentmnt[MAXPATHLEN];
1740 	struct mnttab	mntref;
1741 	char		altzonepath[MAXPATHLEN];
1742 	char		optstr[MAX_MNTOPT_STR];
1743 	int		mflag = MS_OPTIONSTR;
1744 	int		ret;
1745 	int		err;
1746 
1747 	fp = fopen(MNTTAB, "r");
1748 	if (fp == NULL) {
1749 		err = errno;
1750 		be_print_err(gettext("loopback_mount_zonepath: "
1751 		    "failed to open /etc/mnttab\n"));
1752 		return (errno_to_be_err(err));
1753 	}
1754 
1755 	/*
1756 	 * before attempting the loopback mount of zonepath under altroot,
1757 	 * we need to make sure that all intermediate file systems in the
1758 	 * zone path are also mounted under altroot
1759 	 */
1760 
1761 	/* get the parent directory for zonepath */
1762 	p = strrchr(zonepath, '/');
1763 	if (p != NULL && p != zonepath) {
1764 		if ((parent_dir = (char *)calloc(sizeof (char),
1765 		    p - zonepath + 1)) == NULL) {
1766 			ret = BE_ERR_NOMEM;
1767 			goto done;
1768 		}
1769 		(void) strlcpy(parent_dir, zonepath, p - zonepath + 1);
1770 		if (stat(parent_dir, &st) < 0) {
1771 			ret = errno_to_be_err(errno);
1772 			be_print_err(gettext("loopback_mount_zonepath: "
1773 			    "failed to stat %s"),
1774 			    parent_dir);
1775 			free(parent_dir);
1776 			goto done;
1777 		}
1778 		free(parent_dir);
1779 
1780 		/*
1781 		 * After the above stat call, st.st_dev contains ID of the
1782 		 * device over which parent dir resides.
1783 		 * Now, search mnttab and find mount point of parent dir device.
1784 		 */
1785 
1786 		resetmnttab(fp);
1787 		while (getextmntent(fp, &extmtab, sizeof (extmtab)) == 0) {
1788 			dev = makedev(extmtab.mnt_major, extmtab.mnt_minor);
1789 			if (st.st_dev == dev && strcmp(extmtab.mnt_fstype,
1790 			    MNTTYPE_ZFS) == 0) {
1791 				p1 = strchr(extmtab.mnt_special, '/');
1792 				if (p1 == NULL || strncmp(p1 + 1,
1793 				    BE_CONTAINER_DS_NAME, 4) != 0 ||
1794 				    (*(p1 + 5) != '/' && *(p1 + 5) != '\0')) {
1795 					/*
1796 					 * if parent dir is in a shared file
1797 					 * system, check whether it is already
1798 					 * loopback mounted under altroot or
1799 					 * not.  It would have been mounted
1800 					 * already under altroot if it is in
1801 					 * a non-shared filesystem.
1802 					 */
1803 					parentmnt = strdup(extmtab.mnt_mountp);
1804 					(void) snprintf(alt_parentmnt,
1805 					    sizeof (alt_parentmnt), "%s%s",
1806 					    md->altroot, parentmnt);
1807 					mntref.mnt_mountp = alt_parentmnt;
1808 					mntref.mnt_special = parentmnt;
1809 					mntref.mnt_fstype = MNTTYPE_LOFS;
1810 					mntref.mnt_mntopts = NULL;
1811 					mntref.mnt_time = NULL;
1812 					resetmnttab(fp);
1813 					if (getmntany(fp, (struct mnttab *)
1814 					    &extmtab, &mntref) != 0) {
1815 						ret = loopback_mount_zonepath(
1816 						    parentmnt, md);
1817 						if (ret != BE_SUCCESS) {
1818 							free(parentmnt);
1819 							goto done;
1820 						}
1821 					}
1822 					free(parentmnt);
1823 				}
1824 				break;
1825 			}
1826 		}
1827 	}
1828 
1829 
1830 	if (!md->shared_rw) {
1831 		mflag |= MS_RDONLY;
1832 	}
1833 
1834 	(void) snprintf(altzonepath, sizeof (altzonepath), "%s%s",
1835 	    md->altroot, zonepath);
1836 
1837 	/* Add the "nosub" option to the mount options string */
1838 	(void) strlcpy(optstr, MNTOPT_NOSUB, sizeof (optstr));
1839 
1840 	/* Loopback mount this dataset at the altroot */
1841 	if (mount(zonepath, altzonepath, mflag, MNTTYPE_LOFS,
1842 	    NULL, 0, optstr, sizeof (optstr)) != 0) {
1843 		err = errno;
1844 		be_print_err(gettext("loopback_mount_zonepath: "
1845 		    "failed to loopback mount %s at %s: %s\n"),
1846 		    zonepath, altzonepath, strerror(err));
1847 		ret = BE_ERR_MOUNT;
1848 		goto done;
1849 	}
1850 	ret = BE_SUCCESS;
1851 
1852 done :
1853 	(void) fclose(fp);
1854 	return (ret);
1855 }
1856 
1857 /*
1858  * Function:	unmount_shared_fs
1859  * Description:	This function iterates through the mnttab and finds all
1860  *		loopback mount entries that reside within the altroot of
1861  *		where the BE is mounted, and unmounts it.
1862  * Parameters:
1863  *		ud - be_unmount_data_t pointer
1864  * Returns:
1865  *		BE_SUCCESS - Success
1866  *		be_errno_t - Failure
1867  * Scope:
1868  *		Private
1869  */
1870 static int
1871 unmount_shared_fs(be_unmount_data_t *ud)
1872 {
1873 	FILE		*fp = NULL;
1874 	struct mnttab	*table = NULL;
1875 	struct mnttab	ent;
1876 	struct mnttab	*entp = NULL;
1877 	size_t		size = 0;
1878 	int		read_chunk = 32;
1879 	int		i;
1880 	int		altroot_len;
1881 	int		err = 0;
1882 
1883 	errno = 0;
1884 
1885 	/* Read in the mnttab into a table */
1886 	if ((fp = fopen(MNTTAB, "r")) == NULL) {
1887 		err = errno;
1888 		be_print_err(gettext("unmount_shared_fs: "
1889 		    "failed to open mnttab\n"));
1890 		return (errno_to_be_err(err));
1891 	}
1892 
1893 	while (getmntent(fp, &ent) == 0) {
1894 		if (size % read_chunk == 0) {
1895 			table = (struct mnttab *)realloc(table,
1896 			    (size + read_chunk) * sizeof (ent));
1897 		}
1898 		entp = &table[size++];
1899 
1900 		/*
1901 		 * Copy over the current mnttab entry into our table,
1902 		 * copying only the fields that we care about.
1903 		 */
1904 		(void) memset(entp, 0, sizeof (*entp));
1905 		if ((entp->mnt_mountp = strdup(ent.mnt_mountp)) == NULL ||
1906 		    (entp->mnt_fstype = strdup(ent.mnt_fstype)) == NULL) {
1907 			be_print_err(gettext("unmount_shared_fs: "
1908 			    "memory allocation failed\n"));
1909 			return (BE_ERR_NOMEM);
1910 		}
1911 	}
1912 	(void) fclose(fp);
1913 
1914 	/*
1915 	 * Process the mnttab entries in reverse order, looking for
1916 	 * loopback mount entries mounted under our altroot.
1917 	 */
1918 	altroot_len = strlen(ud->altroot);
1919 	for (i = size; i > 0; i--) {
1920 		entp = &table[i - 1];
1921 
1922 		/* If not of type lofs, skip */
1923 		if (strcmp(entp->mnt_fstype, MNTTYPE_LOFS) != 0)
1924 			continue;
1925 
1926 		/* If inside the altroot, unmount it */
1927 		if (strncmp(entp->mnt_mountp, ud->altroot, altroot_len) == 0 &&
1928 		    entp->mnt_mountp[altroot_len] == '/') {
1929 			if (umount(entp->mnt_mountp) != 0) {
1930 				err = errno;
1931 				if (err == EBUSY) {
1932 					(void) sleep(1);
1933 					err = errno = 0;
1934 					if (umount(entp->mnt_mountp) != 0)
1935 						err = errno;
1936 				}
1937 				if (err != 0) {
1938 					be_print_err(gettext(
1939 					    "unmount_shared_fs: "
1940 					    "failed to unmount shared file "
1941 					    "system %s: %s\n"),
1942 					    entp->mnt_mountp, strerror(err));
1943 					return (errno_to_be_err(err));
1944 				}
1945 			}
1946 		}
1947 	}
1948 
1949 	return (BE_SUCCESS);
1950 }
1951 
1952 /*
1953  * Function:	get_mountpoint_from_vfstab
1954  * Description:	This function digs into the vfstab in the given altroot,
1955  *		and searches for an entry for the fs passed in.  If found,
1956  *		it returns the mountpoint of that fs in the mountpoint
1957  *		buffer passed in.  If the get_alt_mountpoint flag is set,
1958  *		it returns the mountpoint with the altroot prepended.
1959  * Parameters:
1960  *		altroot - pointer to the alternate root location
1961  *		fs - pointer to the file system name to look for in the
1962  *			vfstab in altroot
1963  *		mountpoint - pointer to buffer of where the mountpoint of
1964  *			fs will be returned.
1965  *		size_mp - size of mountpoint argument
1966  *		get_alt_mountpoint - flag to indicate whether or not the
1967  *			mountpoint should be populated with the altroot
1968  *			prepended.
1969  * Returns:
1970  *		BE_SUCCESS - Success
1971  *		1 - Failure
1972  * Scope:
1973  *		Private
1974  */
1975 static int
1976 get_mountpoint_from_vfstab(char *altroot, const char *fs, char *mountpoint,
1977     size_t size_mp, boolean_t get_alt_mountpoint)
1978 {
1979 	struct vfstab	vp;
1980 	FILE		*fp = NULL;
1981 	char		alt_vfstab[MAXPATHLEN];
1982 
1983 	/* Generate path to alternate root vfstab */
1984 	(void) snprintf(alt_vfstab, sizeof (alt_vfstab), "%s/etc/vfstab",
1985 	    altroot);
1986 
1987 	/* Open alternate root vfstab */
1988 	if ((fp = fopen(alt_vfstab, "r")) == NULL) {
1989 		be_print_err(gettext("get_mountpoint_from_vfstab: "
1990 		    "failed to open vfstab (%s)\n"), alt_vfstab);
1991 		return (1);
1992 	}
1993 
1994 	if (getvfsspec(fp, &vp, (char *)fs) == 0) {
1995 		/*
1996 		 * Found entry for fs, grab its mountpoint.
1997 		 * If the flag to prepend the altroot into the mountpoint
1998 		 * is set, prepend it.  Otherwise, just return the mountpoint.
1999 		 */
2000 		if (get_alt_mountpoint) {
2001 			(void) snprintf(mountpoint, size_mp, "%s%s", altroot,
2002 			    vp.vfs_mountp);
2003 		} else {
2004 			(void) strlcpy(mountpoint, vp.vfs_mountp, size_mp);
2005 		}
2006 	} else {
2007 		(void) fclose(fp);
2008 		return (1);
2009 	}
2010 
2011 	(void) fclose(fp);
2012 
2013 	return (BE_SUCCESS);
2014 }
2015 
2016 /*
2017  * Function:	fix_mountpoint_callback
2018  * Description:	This callback function is used to iterate through a BE's
2019  *		children filesystems to check if its mountpoint is currently
2020  *		set to be mounted at some specified altroot.  If so, fix it by
2021  *		removing altroot from the beginning of its mountpoint.
2022  *
2023  *		Note - There's no way to tell if a child filesystem's
2024  *		mountpoint isn't broken, and just happens to begin with
2025  *		the altroot we're looking for.  In this case, this function
2026  *		will errantly remove the altroot portion from the beginning
2027  *		of this filesystem's mountpoint.
2028  *
2029  * Parameters:
2030  *		zhp - zfs_handle_t pointer to filesystem being processed.
2031  *		data - altroot of where BE is to be mounted.
2032  * Returns:
2033  *		0 - Success
2034  *		be_errno_t - Failure
2035  * Scope:
2036  *		Private
2037  */
2038 static int
2039 fix_mountpoint_callback(zfs_handle_t *zhp, void *data)
2040 {
2041 	zprop_source_t	sourcetype;
2042 	char		source[ZFS_MAXNAMELEN];
2043 	char		mountpoint[MAXPATHLEN];
2044 	char		*zhp_mountpoint = NULL;
2045 	char		*altroot = data;
2046 	int		ret = 0;
2047 
2048 	/* Get dataset's mountpoint and source values */
2049 	if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
2050 	    sizeof (mountpoint), &sourcetype, source, sizeof (source),
2051 	    B_FALSE) != 0) {
2052 		be_print_err(gettext("fix_mountpoint_callback: "
2053 		    "failed to get mountpoint and sourcetype for %s\n"),
2054 		    zfs_get_name(zhp));
2055 		ZFS_CLOSE(zhp);
2056 		return (BE_ERR_ZFS);
2057 	}
2058 
2059 	/*
2060 	 * If the mountpoint is not inherited and the mountpoint is not
2061 	 * 'legacy', this file system potentially needs its mountpoint
2062 	 * fixed.
2063 	 */
2064 	if (!(sourcetype & ZPROP_SRC_INHERITED) &&
2065 	    strcmp(mountpoint, ZFS_MOUNTPOINT_LEGACY) != 0) {
2066 
2067 		/*
2068 		 * Check if this file system's current mountpoint is
2069 		 * under the altroot we're fixing it against.
2070 		 */
2071 		if (strncmp(mountpoint, altroot, strlen(altroot)) == 0 &&
2072 		    mountpoint[strlen(altroot)] == '/') {
2073 
2074 			/*
2075 			 * Get this dataset's mountpoint relative to the
2076 			 * altroot.
2077 			 */
2078 			zhp_mountpoint = mountpoint + strlen(altroot);
2079 
2080 			/* Fix this dataset's mountpoint value */
2081 			if (zfs_prop_set(zhp,
2082 			    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
2083 			    zhp_mountpoint)) {
2084 				be_print_err(gettext("fix_mountpoint_callback: "
2085 				    "failed to set mountpoint for %s to "
2086 				    "%s: %s\n"), zfs_get_name(zhp),
2087 				    zhp_mountpoint,
2088 				    libzfs_error_description(g_zfs));
2089 				ret = zfs_err_to_be_err(g_zfs);
2090 				ZFS_CLOSE(zhp);
2091 				return (ret);
2092 			}
2093 		}
2094 	}
2095 
2096 	/* Iterate through this dataset's children and fix them */
2097 	if ((ret = zfs_iter_filesystems(zhp, fix_mountpoint_callback,
2098 	    altroot)) != 0) {
2099 		ZFS_CLOSE(zhp);
2100 		return (ret);
2101 	}
2102 
2103 
2104 	ZFS_CLOSE(zhp);
2105 	return (0);
2106 }
2107 
2108 /*
2109  * Function:	be_mount_root
2110  * Description:	This function mounts the root dataset of a BE at the
2111  *		specified altroot.
2112  * Parameters:
2113  *		zhp - zfs_handle_t pointer to root dataset of a BE that is
2114  *		to be mounted at altroot.
2115  *		altroot - location of where to mount the BE root.
2116  * Return:
2117  *		BE_SUCCESS - Success
2118  *		be_errno_t - Failure
2119  * Scope:
2120  *		Private
2121  */
2122 static int
2123 be_mount_root(zfs_handle_t *zhp, char *altroot)
2124 {
2125 	char		mountpoint[MAXPATHLEN];
2126 
2127 	/* Get mountpoint property of dataset */
2128 	if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
2129 	    sizeof (mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
2130 		be_print_err(gettext("be_mount_root: failed to "
2131 		    "get mountpoint property for %s: %s\n"), zfs_get_name(zhp),
2132 		    libzfs_error_description(g_zfs));
2133 		return (zfs_err_to_be_err(g_zfs));
2134 	}
2135 
2136 	/*
2137 	 * Set the canmount property for the BE's root dataset to 'noauto' just
2138 	 * in case it's been set to 'on'.  We do this so that when we change its
2139 	 * mountpoint, zfs won't immediately try to mount it.
2140 	 */
2141 	if (zfs_prop_set(zhp, zfs_prop_to_name(ZFS_PROP_CANMOUNT), "noauto")
2142 	    != 0) {
2143 		be_print_err(gettext("be_mount_root: failed to "
2144 		    "set canmount property to 'noauto' (%s): %s\n"),
2145 		    zfs_get_name(zhp), libzfs_error_description(g_zfs));
2146 		return (zfs_err_to_be_err(g_zfs));
2147 	}
2148 
2149 	/* Set mountpoint for BE's root filesystem */
2150 	if (zfs_prop_set(zhp, zfs_prop_to_name(ZFS_PROP_MOUNTPOINT), altroot)
2151 	    != 0) {
2152 		be_print_err(gettext("be_mount_root: failed to "
2153 		    "set mountpoint of %s to %s: %s\n"),
2154 		    zfs_get_name(zhp), altroot,
2155 		    libzfs_error_description(g_zfs));
2156 		return (zfs_err_to_be_err(g_zfs));
2157 	}
2158 
2159 	/* Mount the BE's root filesystem */
2160 	if (zfs_mount(zhp, NULL, 0) != 0) {
2161 		be_print_err(gettext("be_mount_root: failed to "
2162 		    "mount dataset %s at %s: %s\n"), zfs_get_name(zhp),
2163 		    altroot, libzfs_error_description(g_zfs));
2164 		/*
2165 		 * Set this BE's root filesystem 'mountpoint' property
2166 		 * back to what it was before.
2167 		 */
2168 		(void) zfs_prop_set(zhp, zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
2169 		    mountpoint);
2170 		return (zfs_err_to_be_err(g_zfs));
2171 	}
2172 
2173 	return (BE_SUCCESS);
2174 }
2175 
2176 /*
2177  * Function:	be_unmount_root
2178  * Description:	This function unmounts the root dataset of a BE, but before
2179  *		unmounting, it looks at the BE's vfstab to determine
2180  *		if the root dataset mountpoint should be left as 'legacy'
2181  *		or '/'.  If the vfstab contains an entry for this root
2182  *		dataset with a mountpoint of '/', it sets the mountpoint
2183  *		property to 'legacy'.
2184  *
2185  * Parameters:
2186  *		zhp - zfs_handle_t pointer of the BE root dataset that
2187  *		is currently mounted.
2188  *		ud - be_unmount_data_t pointer providing unmount data
2189  *		for the given BE root dataset.
2190  * Returns:
2191  *		BE_SUCCESS - Success
2192  *		be_errno_t - Failure
2193  * Scope:
2194  *		Private
2195  */
2196 static int
2197 be_unmount_root(zfs_handle_t *zhp, be_unmount_data_t *ud)
2198 {
2199 	char		mountpoint[MAXPATHLEN];
2200 	boolean_t	is_legacy = B_FALSE;
2201 
2202 	/* See if this is a legacy mounted root */
2203 	if (get_mountpoint_from_vfstab(ud->altroot, zfs_get_name(zhp),
2204 	    mountpoint, sizeof (mountpoint), B_FALSE) == BE_SUCCESS &&
2205 	    strcmp(mountpoint, "/") == 0) {
2206 		is_legacy = B_TRUE;
2207 	}
2208 
2209 	/* Unmount the dataset */
2210 	if (zfs_unmount(zhp, NULL, ud->force ? MS_FORCE : 0) != 0) {
2211 		be_print_err(gettext("be_unmount_root: failed to "
2212 		    "unmount BE root dataset %s: %s\n"), zfs_get_name(zhp),
2213 		    libzfs_error_description(g_zfs));
2214 		return (zfs_err_to_be_err(g_zfs));
2215 	}
2216 
2217 	/* Set canmount property for this BE's root filesystem to noauto */
2218 	if (zfs_prop_set(zhp, zfs_prop_to_name(ZFS_PROP_CANMOUNT), "noauto")
2219 	    != 0) {
2220 		be_print_err(gettext("be_unmount_root: failed to "
2221 		    "set canmount property for %s to 'noauto': %s\n"),
2222 		    zfs_get_name(zhp), libzfs_error_description(g_zfs));
2223 		return (zfs_err_to_be_err(g_zfs));
2224 	}
2225 
2226 	/*
2227 	 * Set mountpoint for BE's root dataset back to '/', or 'legacy'
2228 	 * if its a legacy mounted root.
2229 	 */
2230 	if (zfs_prop_set(zhp, zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
2231 	    is_legacy ? ZFS_MOUNTPOINT_LEGACY : "/") != 0) {
2232 		be_print_err(gettext("be_unmount_root: failed to "
2233 		    "set mountpoint of %s to %s\n"), zfs_get_name(zhp),
2234 		    is_legacy ? ZFS_MOUNTPOINT_LEGACY : "/");
2235 		return (zfs_err_to_be_err(g_zfs));
2236 	}
2237 
2238 	return (BE_SUCCESS);
2239 }
2240 
2241 /*
2242  * Function:	fix_mountpoint
2243  * Description:	This function checks the mountpoint of an unmounted BE to make
2244  *		sure that it is set to either 'legacy' or '/'.  If it's not,
2245  *		then we're in a situation where an unmounted BE has some random
2246  *		mountpoint set for it.  (This could happen if the system was
2247  *		rebooted while an inactive BE was mounted).  This function
2248  *		attempts to fix its mountpoints.
2249  * Parameters:
2250  *		zhp - zfs_handle_t pointer to root dataset of the BE
2251  *		whose mountpoint needs to be checked.
2252  * Return:
2253  *		BE_SUCCESS - Success
2254  *		be_errno_t - Failure
2255  * Scope:
2256  *		Private
2257  */
2258 static int
2259 fix_mountpoint(zfs_handle_t *zhp)
2260 {
2261 	be_unmount_data_t	ud = { 0 };
2262 	char	*altroot = NULL;
2263 	char	mountpoint[MAXPATHLEN];
2264 	int	ret = BE_SUCCESS;
2265 
2266 	/*
2267 	 * Record what this BE's root dataset mountpoint property is currently
2268 	 * set to.
2269 	 */
2270 	if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
2271 	    sizeof (mountpoint), NULL, NULL, 0, B_FALSE) != 0) {
2272 		be_print_err(gettext("fix_mountpoint: failed to get "
2273 		    "mountpoint property of (%s): %s\n"), zfs_get_name(zhp),
2274 		    libzfs_error_description(g_zfs));
2275 		return (BE_ERR_ZFS);
2276 	}
2277 
2278 	/*
2279 	 * If the root dataset mountpoint is set to 'legacy' or '/', we're okay.
2280 	 */
2281 	if (strcmp(mountpoint, ZFS_MOUNTPOINT_LEGACY) == 0 ||
2282 	    strcmp(mountpoint, "/") == 0) {
2283 		return (BE_SUCCESS);
2284 	}
2285 
2286 	/*
2287 	 * Iterate through this BE's children datasets and fix
2288 	 * them if they need fixing.
2289 	 */
2290 	if (zfs_iter_filesystems(zhp, fix_mountpoint_callback, mountpoint)
2291 	    != 0) {
2292 		return (BE_ERR_ZFS);
2293 	}
2294 
2295 	/*
2296 	 * The process of mounting and unmounting the root file system
2297 	 * will fix its mountpoint to correctly be either 'legacy' or '/'
2298 	 * since be_unmount_root will do the right thing by looking at
2299 	 * its vfstab.
2300 	 */
2301 
2302 	/* Generate temporary altroot to mount the root file system */
2303 	if ((ret = be_make_tmp_mountpoint(&altroot)) != BE_SUCCESS) {
2304 		be_print_err(gettext("fix_mountpoint: failed to "
2305 		    "make temporary mountpoint\n"));
2306 		return (ret);
2307 	}
2308 
2309 	/* Mount and unmount the root. */
2310 	if ((ret = be_mount_root(zhp, altroot)) != BE_SUCCESS) {
2311 		be_print_err(gettext("fix_mountpoint: failed to "
2312 		    "mount BE root file system\n"));
2313 		goto cleanup;
2314 	}
2315 	ud.altroot = altroot;
2316 	if ((ret = be_unmount_root(zhp, &ud)) != BE_SUCCESS) {
2317 		be_print_err(gettext("fix_mountpoint: failed to "
2318 		    "unmount BE root file system\n"));
2319 		goto cleanup;
2320 	}
2321 
2322 cleanup:
2323 	free(altroot);
2324 
2325 	return (ret);
2326 }
2327 
2328 /*
2329  * Function:	be_mount_zones
2330  * Description:	This function finds all supported non-global zones in the
2331  *		given global BE and mounts them with respect to where the
2332  *		global BE is currently mounted.  The global BE datasets
2333  *		(including its shared datasets) are expected to already
2334  *		be mounted.
2335  * Parameters:
2336  *		be_zhp - zfs_handle_t pointer to the root dataset of the
2337  *			global BE.
2338  *		md - be_mount_data_t pointer to data for global BE.
2339  * Returns:
2340  *		BE_SUCCESS - Success
2341  *		be_errno_t - Failure
2342  * Scope:
2343  *		Private
2344  */
2345 static int
2346 be_mount_zones(zfs_handle_t *be_zhp, be_mount_data_t *md)
2347 {
2348 	zoneBrandList_t	*brands = NULL;
2349 	zoneList_t	zlst = NULL;
2350 	char		*zonename = NULL;
2351 	char		*zonepath = NULL;
2352 	char		*zonepath_ds = NULL;
2353 	int		k;
2354 	int		ret = BE_SUCCESS;
2355 
2356 	z_set_zone_root(md->altroot);
2357 
2358 	if ((brands = be_get_supported_brandlist()) == NULL) {
2359 		be_print_err(gettext("be_mount_zones: "
2360 		    "no supported brands\n"));
2361 		return (BE_SUCCESS);
2362 	}
2363 
2364 	zlst = z_get_nonglobal_zone_list_by_brand(brands);
2365 	if (zlst == NULL) {
2366 		z_free_brand_list(brands);
2367 		return (BE_SUCCESS);
2368 	}
2369 
2370 	for (k = 0; (zonename = z_zlist_get_zonename(zlst, k)) != NULL; k++) {
2371 		if (z_zlist_get_current_state(zlst, k) ==
2372 		    ZONE_STATE_INSTALLED) {
2373 			zonepath = z_zlist_get_zonepath(zlst, k);
2374 
2375 			/*
2376 			 * Get the dataset of this zonepath in current BE.
2377 			 * If its not a dataset, skip it.
2378 			 */
2379 			if ((zonepath_ds = be_get_ds_from_dir(zonepath))
2380 			    == NULL)
2381 				continue;
2382 
2383 			/*
2384 			 * Check if this zone is supported based on
2385 			 * the dataset of its zonepath
2386 			 */
2387 			if (!be_zone_supported(zonepath_ds)) {
2388 				free(zonepath_ds);
2389 				zonepath_ds = NULL;
2390 				continue;
2391 			}
2392 
2393 			/*
2394 			 * if BE's shared file systems are already mounted,
2395 			 * zone path dataset would have already been lofs
2396 			 * mounted under altroot. Otherwise, we need to do
2397 			 * it here.
2398 			 */
2399 			if (!md->shared_fs) {
2400 				ret = loopback_mount_zonepath(zonepath, md);
2401 				if (ret != BE_SUCCESS)
2402 					goto done;
2403 			}
2404 
2405 
2406 			/* Mount this zone */
2407 			ret = be_mount_one_zone(be_zhp, md, zonename,
2408 			    zonepath, zonepath_ds);
2409 
2410 			free(zonepath_ds);
2411 			zonepath_ds = NULL;
2412 
2413 			if (ret != BE_SUCCESS) {
2414 				be_print_err(gettext("be_mount_zones: "
2415 				    "failed to mount zone %s under "
2416 				    "altroot %s\n"), zonename, md->altroot);
2417 				goto done;
2418 			}
2419 		}
2420 	}
2421 
2422 done:
2423 	z_free_brand_list(brands);
2424 	z_free_zone_list(zlst);
2425 	/*
2426 	 * libinstzones caches mnttab and uses cached version for resolving lofs
2427 	 * mounts when we call z_resolve_lofs. It creates the cached version
2428 	 * when the first call to z_resolve_lofs happens. So, library's cached
2429 	 * mnttab doesn't contain entries for lofs mounts created in the above
2430 	 * loop. Because of this, subsequent calls to z_resolve_lofs would fail
2431 	 * to resolve these lofs mounts. So, here we destroy library's cached
2432 	 * mnttab to force its recreation when the next call to z_resolve_lofs
2433 	 * happens.
2434 	 */
2435 	z_destroyMountTable();
2436 	return (ret);
2437 }
2438 
2439 /*
2440  * Function:	be_unmount_zones
2441  * Description:	This function finds all supported non-global zones in the
2442  *		given mounted global BE and unmounts them.
2443  * Parameters:
2444  *		ud - unmount_data_t pointer data for the global BE.
2445  * Returns:
2446  *		BE_SUCCESS - Success
2447  *		be_errno_t - Failure
2448  * Scope:
2449  *		Private
2450  */
2451 static int
2452 be_unmount_zones(be_unmount_data_t *ud)
2453 {
2454 	zoneBrandList_t		*brands = NULL;
2455 	zoneList_t		zlst = NULL;
2456 	char			*zonename = NULL;
2457 	char			*zonepath = NULL;
2458 	char			alt_zonepath[MAXPATHLEN];
2459 	char			*zonepath_ds = NULL;
2460 	int			k;
2461 	int			ret = BE_SUCCESS;
2462 
2463 	z_set_zone_root(ud->altroot);
2464 
2465 	if ((brands = be_get_supported_brandlist()) == NULL) {
2466 		be_print_err(gettext("be_unmount_zones: "
2467 		    "no supported brands\n"));
2468 		return (BE_SUCCESS);
2469 	}
2470 
2471 	zlst = z_get_nonglobal_zone_list_by_brand(brands);
2472 	if (zlst == NULL) {
2473 		z_free_brand_list(brands);
2474 		return (BE_SUCCESS);
2475 	}
2476 
2477 	for (k = 0; (zonename = z_zlist_get_zonename(zlst, k)) != NULL; k++) {
2478 		if (z_zlist_get_current_state(zlst, k) ==
2479 		    ZONE_STATE_INSTALLED) {
2480 			zonepath = z_zlist_get_zonepath(zlst, k);
2481 
2482 			/* Build zone's zonepath wrt the global BE altroot */
2483 			(void) snprintf(alt_zonepath, sizeof (alt_zonepath),
2484 			    "%s%s", ud->altroot, zonepath);
2485 
2486 			/*
2487 			 * Get the dataset of this zonepath.  If its not
2488 			 * a dataset, skip it.
2489 			 */
2490 			if ((zonepath_ds = be_get_ds_from_dir(alt_zonepath))
2491 			    == NULL)
2492 				continue;
2493 
2494 			/*
2495 			 * Check if this zone is supported based on the
2496 			 * dataset of its zonepath.
2497 			 */
2498 			if (!be_zone_supported(zonepath_ds)) {
2499 				free(zonepath_ds);
2500 				zonepath_ds = NULL;
2501 				continue;
2502 			}
2503 
2504 			/* Unmount this zone */
2505 			ret = be_unmount_one_zone(ud, zonename, zonepath,
2506 			    zonepath_ds);
2507 
2508 			free(zonepath_ds);
2509 			zonepath_ds = NULL;
2510 
2511 			if (ret != BE_SUCCESS) {
2512 				be_print_err(gettext("be_unmount_zones:"
2513 				    " failed to unmount zone %s from "
2514 				    "altroot %s\n"), zonename, ud->altroot);
2515 				goto done;
2516 			}
2517 		}
2518 	}
2519 
2520 done:
2521 	z_free_brand_list(brands);
2522 	z_free_zone_list(zlst);
2523 	return (ret);
2524 }
2525 
2526 /*
2527  * Function:	be_mount_one_zone
2528  * Description:	This function is called to mount one zone for a given
2529  *		global BE.
2530  * Parameters:
2531  *		be_zhp - zfs_handle_t pointer to the root dataset of the
2532  *			global BE
2533  *		md - be_mount_data_t pointer to data for global BE
2534  *		zonename - name of zone to mount
2535  *		zonepath - zonepath of zone to mount
2536  *		zonepath_ds - dataset for the zonepath
2537  * Returns:
2538  *		BE_SUCCESS - Success
2539  *		be_errno_t - Failure
2540  * Scope:
2541  *		Private
2542  */
2543 static int
2544 be_mount_one_zone(zfs_handle_t *be_zhp, be_mount_data_t *md, char *zonename,
2545     char *zonepath, char *zonepath_ds)
2546 {
2547 	be_mount_data_t	zone_md = { 0 };
2548 	zfs_handle_t	*zone_zhp = NULL;
2549 	char		zone_altroot[MAXPATHLEN];
2550 	char		zoneroot[MAXPATHLEN];
2551 	char		zoneroot_ds[MAXPATHLEN];
2552 	int		ret = BE_SUCCESS;
2553 
2554 	/* Find the active zone root dataset for this zone for this BE */
2555 	if ((ret = be_find_active_zone_root(be_zhp, zonepath_ds, zoneroot_ds,
2556 	    sizeof (zoneroot_ds))) == BE_ERR_ZONE_NO_ACTIVE_ROOT) {
2557 		be_print_err(gettext("be_mount_one_zone: did not "
2558 		    "find active zone root for zone %s, skipping ...\n"),
2559 		    zonename);
2560 		return (BE_SUCCESS);
2561 	} else if (ret != BE_SUCCESS) {
2562 		be_print_err(gettext("be_mount_one_zone: failed to "
2563 		    "find active zone root for zone %s\n"), zonename);
2564 		return (ret);
2565 	}
2566 
2567 	/* Get handle to active zoneroot dataset */
2568 	if ((zone_zhp = zfs_open(g_zfs, zoneroot_ds, ZFS_TYPE_FILESYSTEM))
2569 	    == NULL) {
2570 		be_print_err(gettext("be_mount_one_zone: failed to "
2571 		    "open zone root dataset (%s): %s\n"), zoneroot_ds,
2572 		    libzfs_error_description(g_zfs));
2573 		return (zfs_err_to_be_err(g_zfs));
2574 	}
2575 
2576 	/* Generate string for zone's altroot path */
2577 	be_make_zoneroot(zonepath, zoneroot, sizeof (zoneroot));
2578 	(void) strlcpy(zone_altroot, md->altroot, sizeof (zone_altroot));
2579 	(void) strlcat(zone_altroot, zoneroot, sizeof (zone_altroot));
2580 
2581 	/* Build mount_data for the zone */
2582 	zone_md.altroot = zone_altroot;
2583 	zone_md.shared_fs = md->shared_fs;
2584 	zone_md.shared_rw = md->shared_rw;
2585 
2586 	/* Mount the zone's root file system */
2587 	if ((ret = be_mount_zone_root(zone_zhp, &zone_md)) != BE_SUCCESS) {
2588 		be_print_err(gettext("be_mount_one_zone: failed to "
2589 		    "mount zone root file system at %s\n"), zone_altroot);
2590 		goto done;
2591 	}
2592 
2593 	/* Iterate through zone's children filesystems */
2594 	if ((ret = zfs_iter_filesystems(zone_zhp, be_mount_callback,
2595 	    zone_altroot)) != 0) {
2596 		be_print_err(gettext("be_mount_one_zone: failed to "
2597 		    "mount zone subordinate file systems at %s\n"),
2598 		    zone_altroot);
2599 		goto done;
2600 	}
2601 
2602 	/* TODO: Mount all shared file systems for this zone */
2603 
2604 done:
2605 	ZFS_CLOSE(zone_zhp);
2606 	return (ret);
2607 }
2608 
2609 /*
2610  * Function:	be_unmount_one_zone
2611  * Description:	This function unmount one zone for a give global BE.
2612  * Parameters:
2613  *		ud - be_unmount_data_t pointer to data for global BE
2614  *		zonename - name of zone to unmount
2615  *		zonepath - zonepath of the zone to unmount
2616  *		zonepath_ds - dataset for the zonepath
2617  * Returns:
2618  *		BE_SUCCESS - Success
2619  *		be_errno_t - Failure
2620  * Scope:
2621  *		Private
2622  */
2623 static int
2624 be_unmount_one_zone(be_unmount_data_t *ud, char *zonename, char *zonepath,
2625     char *zonepath_ds)
2626 {
2627 	be_unmount_data_t	zone_ud = { 0 };
2628 	zfs_handle_t	*zone_zhp = NULL;
2629 	char		zone_altroot[MAXPATHLEN];
2630 	char		zoneroot[MAXPATHLEN];
2631 	char		zoneroot_ds[MAXPATHLEN];
2632 	int		ret = BE_SUCCESS;
2633 
2634 	/* Generate string for zone's alternate root path */
2635 	be_make_zoneroot(zonepath, zoneroot, sizeof (zoneroot));
2636 	(void) strlcpy(zone_altroot, ud->altroot, sizeof (zone_altroot));
2637 	(void) strlcat(zone_altroot, zoneroot, sizeof (zone_altroot));
2638 
2639 	/* Build be_unmount_data for zone */
2640 	zone_ud.altroot = zone_altroot;
2641 	zone_ud.force = ud->force;
2642 
2643 	/* Find the mounted zone root dataset for this zone for this BE */
2644 	if ((ret = be_find_mounted_zone_root(zone_altroot, zonepath_ds,
2645 	    zoneroot_ds, sizeof (zoneroot_ds))) == BE_ERR_NO_MOUNTED_ZONE) {
2646 		be_print_err(gettext("be_unmount_one_zone: did not "
2647 		    "find any zone root mounted for zone %s\n"), zonename);
2648 		return (BE_SUCCESS);
2649 	} else if (ret != BE_SUCCESS) {
2650 		be_print_err(gettext("be_unmount_one_zone: failed to "
2651 		    "find mounted zone root for zone %s\n"), zonename);
2652 		return (ret);
2653 	}
2654 
2655 	/* Get handle to zoneroot dataset mounted for this BE */
2656 	if ((zone_zhp = zfs_open(g_zfs, zoneroot_ds, ZFS_TYPE_FILESYSTEM))
2657 	    == NULL) {
2658 		be_print_err(gettext("be_unmount_one_zone: failed to "
2659 		    "open mounted zone root dataset (%s): %s\n"), zoneroot_ds,
2660 		    libzfs_error_description(g_zfs));
2661 		return (zfs_err_to_be_err(g_zfs));
2662 	}
2663 
2664 	/* TODO: Unmount all shared file systems for this zone */
2665 
2666 	/* Iterate through zone's children filesystems and unmount them */
2667 	if ((ret = zfs_iter_filesystems(zone_zhp, be_unmount_callback,
2668 	    &zone_ud)) != 0) {
2669 		be_print_err(gettext("be_unmount_one_zone: failed to "
2670 		    "unmount zone subordinate file systems at %s\n"),
2671 		    zone_altroot);
2672 		goto done;
2673 	}
2674 
2675 	/* Unmount the zone's root filesystem */
2676 	if ((ret = be_unmount_zone_root(zone_zhp, &zone_ud)) != BE_SUCCESS) {
2677 		be_print_err(gettext("be_unmount_one_zone: failed to "
2678 		    "unmount zone root file system at %s\n"), zone_altroot);
2679 		goto done;
2680 	}
2681 
2682 done:
2683 	ZFS_CLOSE(zone_zhp);
2684 	return (ret);
2685 }
2686 
2687 /*
2688  * Function:	be_get_ds_from_dir_callback
2689  * Description:	This is a callback function used to iterate all datasets
2690  *		to find the one that is currently mounted at the directory
2691  *		being searched for.  If matched, the name of the dataset is
2692  *		returned in heap storage, so the caller is responsible for
2693  *		freeing it.
2694  * Parameters:
2695  *		zhp - zfs_handle_t pointer to current dataset being processed.
2696  *		data - dir_data_t pointer providing name of directory being
2697  *			searched for.
2698  * Returns:
2699  *		1 - This dataset is mounted at directory being searched for.
2700  *		0 - This dataset is not mounted at directory being searched for.
2701  * Scope:
2702  *		Private
2703  */
2704 static int
2705 be_get_ds_from_dir_callback(zfs_handle_t *zhp, void *data)
2706 {
2707 	dir_data_t	*dd = data;
2708 	char		*mp = NULL;
2709 	int		zret = 0;
2710 
2711 	if (zfs_get_type(zhp) != ZFS_TYPE_FILESYSTEM) {
2712 		ZFS_CLOSE(zhp);
2713 		return (0);
2714 	}
2715 
2716 	if (zfs_is_mounted(zhp, &mp) && mp != NULL &&
2717 	    strcmp(mp, dd->dir) == 0) {
2718 		if ((dd->ds = strdup(zfs_get_name(zhp))) == NULL) {
2719 			be_print_err(gettext("be_get_ds_from_dir_callback: "
2720 			    "memory allocation failed\n"));
2721 			ZFS_CLOSE(zhp);
2722 			return (0);
2723 		}
2724 		ZFS_CLOSE(zhp);
2725 		return (1);
2726 	}
2727 
2728 	zret = zfs_iter_filesystems(zhp, be_get_ds_from_dir_callback, dd);
2729 
2730 	ZFS_CLOSE(zhp);
2731 
2732 	return (zret);
2733 }
2734