/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2013 Nexenta Systems, Inc. All rights reserved.
 * Copyright (c) 2014, 2015 by Delphix. All rights reserved.
 * Copyright (c) 2016 Martin Matuska. All rights reserved.
 * Copyright 2022 OmniOS Community Edition (OmniOSce) Association.
 */

/*
 * System includes
 */

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <libgen.h>
#include <libintl.h>
#include <libnvpair.h>
#include <libzfs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mnttab.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include <libbe.h>
#include <libbe_priv.h>
#include <libzfsbootenv.h>

/* Library wide variables */
libzfs_handle_t *g_zfs = NULL;

/* Private function prototypes */
static int _be_destroy(const char *, be_destroy_data_t *);
static int be_destroy_zones(char *, char *, be_destroy_data_t *);
static int be_destroy_zone_roots(char *, be_destroy_data_t *);
static int be_destroy_zone_roots_callback(zfs_handle_t *, void *);
static int be_copy_zones(char *, char *, char *);
static int be_clone_fs_callback(zfs_handle_t *, void *);
static int be_destroy_callback(zfs_handle_t *, void *);
static int be_send_fs_callback(zfs_handle_t *, void *);
static int be_demote_callback(zfs_handle_t *, void *);
static int be_demote_find_clone_callback(zfs_handle_t *, void *);
static int be_has_snapshot_callback(zfs_handle_t *, void *);
static int be_demote_get_one_clone(zfs_handle_t *, void *);
static int be_get_snap(char *, char **);
static int be_prep_clone_send_fs(zfs_handle_t *, be_transaction_data_t *,
    char *, int);
static boolean_t be_create_container_ds(char *);
static char *be_get_zone_be_name(char *root_ds, char *container_ds);
static int be_zone_root_exists_callback(zfs_handle_t *, void *);

/* ******************************************************************** */
/*                      Public Functions                                */
/* ******************************************************************** */

/*
 * Function:    be_init
 * Description: Creates the initial datasets for a BE and leaves them
 *              unpopulated.  The resultant BE can be mounted but can't
 *              yet be activated or booted.
 * Parameters:
 *              be_attrs - pointer to nvlist_t of attributes being passed in.
 *                      The following attributes are used by this function:
 *
 *                      BE_ATTR_NEW_BE_NAME             *required
 *                      BE_ATTR_NEW_BE_POOL             *required
 *                      BE_ATTR_ZFS_PROPERTIES          *optional
 *                      BE_ATTR_FS_NAMES                *optional
 *                      BE_ATTR_FS_NUM                  *optional
 *                      BE_ATTR_SHARED_FS_NAMES         *optional
 *                      BE_ATTR_SHARED_FS_NUM           *optional
 * Return:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Public
 */
int
be_init(nvlist_t *be_attrs)
{
        be_transaction_data_t   bt = { 0 };
        zpool_handle_t  *zlp;
        nvlist_t        *zfs_props = NULL;
        char            nbe_root_ds[MAXPATHLEN];
        char            child_fs[MAXPATHLEN];
        char            **fs_names = NULL;
        char            **shared_fs_names = NULL;
        uint16_t        fs_num = 0;
        uint16_t        shared_fs_num = 0;
        int             nelem;
        int             i;
        int             zret = 0, ret = BE_SUCCESS;

        /* Initialize libzfs handle */
        if (!be_zfs_init())
                return (BE_ERR_INIT);

        /* Get new BE name */
        if (nvlist_lookup_string(be_attrs, BE_ATTR_NEW_BE_NAME, &bt.nbe_name)
            != 0) {
                be_print_err(gettext("be_init: failed to lookup "
                    "BE_ATTR_NEW_BE_NAME attribute\n"));
                return (BE_ERR_INVAL);
        }

        /* Validate new BE name */
        if (!be_valid_be_name(bt.nbe_name)) {
                be_print_err(gettext("be_init: invalid BE name %s\n"),
                    bt.nbe_name);
                return (BE_ERR_INVAL);
        }

        /* Get zpool name */
        if (nvlist_lookup_string(be_attrs, BE_ATTR_NEW_BE_POOL, &bt.nbe_zpool)
            != 0) {
                be_print_err(gettext("be_init: failed to lookup "
                    "BE_ATTR_NEW_BE_POOL attribute\n"));
                return (BE_ERR_INVAL);
        }

        /* Get file system attributes */
        nelem = 0;
        if (nvlist_lookup_pairs(be_attrs, 0,
            BE_ATTR_FS_NUM, DATA_TYPE_UINT16, &fs_num,
            BE_ATTR_FS_NAMES, DATA_TYPE_STRING_ARRAY, &fs_names, &nelem,
            NULL) != 0) {
                be_print_err(gettext("be_init: failed to lookup fs "
                    "attributes\n"));
                return (BE_ERR_INVAL);
        }
        if (nelem != fs_num) {
                be_print_err(gettext("be_init: size of FS_NAMES array (%d) "
                    "does not match FS_NUM (%d)\n"), nelem, fs_num);
                return (BE_ERR_INVAL);
        }

        /* Get shared file system attributes */
        nelem = 0;
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_SHARED_FS_NUM, DATA_TYPE_UINT16, &shared_fs_num,
            BE_ATTR_SHARED_FS_NAMES, DATA_TYPE_STRING_ARRAY, &shared_fs_names,
            &nelem, NULL) != 0) {
                be_print_err(gettext("be_init: failed to lookup "
                    "shared fs attributes\n"));
                return (BE_ERR_INVAL);
        }
        if (nelem != shared_fs_num) {
                be_print_err(gettext("be_init: size of SHARED_FS_NAMES "
                    "array does not match SHARED_FS_NUM\n"));
                return (BE_ERR_INVAL);
        }

        /* Verify that nbe_zpool exists */
        if ((zlp = zpool_open(g_zfs, bt.nbe_zpool)) == NULL) {
                be_print_err(gettext("be_init: failed to "
                    "find existing zpool (%s): %s\n"), bt.nbe_zpool,
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }
        zpool_close(zlp);

        /*
         * Verify BE container dataset in nbe_zpool exists.
         * If not, create it.
         */
        if (!be_create_container_ds(bt.nbe_zpool))
                return (BE_ERR_CREATDS);

        /*
         * Verify that nbe_name doesn't already exist in some pool.
         */
        if ((zret = zpool_iter(g_zfs, be_exists_callback, bt.nbe_name)) > 0) {
                be_print_err(gettext("be_init: BE (%s) already exists\n"),
                    bt.nbe_name);
                return (BE_ERR_BE_EXISTS);
        } else if (zret < 0) {
                be_print_err(gettext("be_init: zpool_iter failed: %s\n"),
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /* Generate string for BE's root dataset */
        if ((ret = be_make_root_ds(bt.nbe_zpool, bt.nbe_name, nbe_root_ds,
            sizeof (nbe_root_ds))) != BE_SUCCESS) {
                be_print_err(gettext("%s: failed to get BE container dataset "
                    "for %s/%s\n"), __func__, bt.nbe_zpool, bt.nbe_name);
                return (ret);
        }

        /*
         * Create property list for new BE root dataset.  If some
         * zfs properties were already provided by the caller, dup
         * that list.  Otherwise initialize a new property list.
         */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_ZFS_PROPERTIES, DATA_TYPE_NVLIST, &zfs_props, NULL)
            != 0) {
                be_print_err(gettext("be_init: failed to lookup "
                    "BE_ATTR_ZFS_PROPERTIES attribute\n"));
                return (BE_ERR_INVAL);
        }
        if (zfs_props != NULL) {
                /* Make sure its a unique nvlist */
                if (!(zfs_props->nvl_nvflag & NV_UNIQUE_NAME) &&
                    !(zfs_props->nvl_nvflag & NV_UNIQUE_NAME_TYPE)) {
                        be_print_err(gettext("be_init: ZFS property list "
                            "not unique\n"));
                        return (BE_ERR_INVAL);
                }

                /* Dup the list */
                if (nvlist_dup(zfs_props, &bt.nbe_zfs_props, 0) != 0) {
                        be_print_err(gettext("be_init: failed to dup ZFS "
                            "property list\n"));
                        return (BE_ERR_NOMEM);
                }
        } else {
                /* Initialize new nvlist */
                if (nvlist_alloc(&bt.nbe_zfs_props, NV_UNIQUE_NAME, 0) != 0) {
                        be_print_err(gettext("be_init: internal "
                            "error: out of memory\n"));
                        return (BE_ERR_NOMEM);
                }
        }

        /* Set the mountpoint property for the root dataset */
        if (nvlist_add_string(bt.nbe_zfs_props,
            zfs_prop_to_name(ZFS_PROP_MOUNTPOINT), "/") != 0) {
                be_print_err(gettext("be_init: internal error "
                    "out of memory\n"));
                ret = BE_ERR_NOMEM;
                goto done;
        }

        /* Set the 'canmount' property */
        if (nvlist_add_string(bt.nbe_zfs_props,
            zfs_prop_to_name(ZFS_PROP_CANMOUNT), "noauto") != 0) {
                be_print_err(gettext("be_init: internal error "
                    "out of memory\n"));
                ret = BE_ERR_NOMEM;
                goto done;
        }

        /* Create BE root dataset for the new BE */
        if (zfs_create(g_zfs, nbe_root_ds, ZFS_TYPE_FILESYSTEM,
            bt.nbe_zfs_props) != 0) {
                be_print_err(gettext("be_init: failed to "
                    "create BE root dataset (%s): %s\n"), nbe_root_ds,
                    libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                goto done;
        }

        /* Set UUID for new BE */
        if ((ret = be_set_uuid(nbe_root_ds)) != BE_SUCCESS) {
                be_print_err(gettext("be_init: failed to "
                    "set uuid for new BE\n"));
        }

        /*
         * Clear the mountpoint property so that the non-shared
         * file systems created below inherit their mountpoints.
         */
        (void) nvlist_remove(bt.nbe_zfs_props,
            zfs_prop_to_name(ZFS_PROP_MOUNTPOINT), DATA_TYPE_STRING);

        /* Create the new BE's non-shared file systems */
        for (i = 0; i < fs_num && fs_names[i]; i++) {
                /*
                 * If fs == "/", skip it;
                 * we already created the root dataset
                 */
                if (strcmp(fs_names[i], "/") == 0)
                        continue;

                /* Generate string for file system */
                (void) snprintf(child_fs, sizeof (child_fs), "%s%s",
                    nbe_root_ds, fs_names[i]);

                /* Create file system */
                if (zfs_create(g_zfs, child_fs, ZFS_TYPE_FILESYSTEM,
                    bt.nbe_zfs_props) != 0) {
                        be_print_err(gettext("be_init: failed to create "
                            "BE's child dataset (%s): %s\n"), child_fs,
                            libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        goto done;
                }
        }

        /* Create the new BE's shared file systems */
        if (shared_fs_num > 0) {
                nvlist_t        *props = NULL;

                if (nvlist_alloc(&props, NV_UNIQUE_NAME, 0) != 0) {
                        be_print_err(gettext("be_init: nvlist_alloc failed\n"));
                        ret = BE_ERR_NOMEM;
                        goto done;
                }

                for (i = 0; i < shared_fs_num; i++) {
                        /* Generate string for shared file system */
                        (void) snprintf(child_fs, sizeof (child_fs), "%s%s",
                            bt.nbe_zpool, shared_fs_names[i]);

                        if (nvlist_add_string(props,
                            zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
                            shared_fs_names[i]) != 0) {
                                be_print_err(gettext("be_init: "
                                    "internal error: out of memory\n"));
                                nvlist_free(props);
                                ret = BE_ERR_NOMEM;
                                goto done;
                        }

                        /* Create file system if it doesn't already exist */
                        if (zfs_dataset_exists(g_zfs, child_fs,
                            ZFS_TYPE_FILESYSTEM)) {
                                continue;
                        }
                        if (zfs_create(g_zfs, child_fs, ZFS_TYPE_FILESYSTEM,
                            props) != 0) {
                                be_print_err(gettext("be_init: failed to "
                                    "create BE's shared dataset (%s): %s\n"),
                                    child_fs, libzfs_error_description(g_zfs));
                                ret = zfs_err_to_be_err(g_zfs);
                                nvlist_free(props);
                                goto done;
                        }
                }

                nvlist_free(props);
        }

done:
        nvlist_free(bt.nbe_zfs_props);

        be_zfs_fini();

        return (ret);
}

/*
 * Function:    be_destroy
 * Description: Destroy a BE and all of its children datasets, snapshots and
 *              zones that belong to the parent BE.
 * Parameters:
 *              be_attrs - pointer to nvlist_t of attributes being passed in.
 *                      The following attributes are used by this function:
 *
 *                      BE_ATTR_ORIG_BE_NAME            *required
 *                      BE_ATTR_DESTROY_FLAGS           *optional
 * Return:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Public
 */
int
be_destroy(nvlist_t *be_attrs)
{
        zfs_handle_t            *zhp = NULL;
        be_transaction_data_t   bt = { 0 };
        be_transaction_data_t   cur_bt = { 0 };
        be_destroy_data_t       dd = { 0 };
        int                     ret = BE_SUCCESS;
        uint16_t                flags = 0;
        boolean_t               bs_found = B_FALSE;
        int                     zret;
        char                    obe_root_ds[MAXPATHLEN];
        char                    *mp = NULL;

        /* Initialize libzfs handle */
        if (!be_zfs_init())
                return (BE_ERR_INIT);

        /* Get name of BE to delete */
        if (nvlist_lookup_string(be_attrs, BE_ATTR_ORIG_BE_NAME, &bt.obe_name)
            != 0) {
                be_print_err(gettext("be_destroy: failed to lookup "
                    "BE_ATTR_ORIG_BE_NAME attribute\n"));
                return (BE_ERR_INVAL);
        }

        /*
         * Validate BE name. If valid, then check that the original BE is not
         * the active BE. If it is the 'active' BE then return an error code
         * since we can't destroy the active BE.
         */
        if (!be_valid_be_name(bt.obe_name)) {
                be_print_err(gettext("be_destroy: invalid BE name %s\n"),
                    bt.obe_name);
                return (BE_ERR_INVAL);
        } else if (bt.obe_name != NULL) {
                if ((ret = be_find_current_be(&cur_bt)) != BE_SUCCESS) {
                        return (ret);
                }
                if (strcmp(cur_bt.obe_name, bt.obe_name) == 0) {
                        return (BE_ERR_DESTROY_CURR_BE);
                }
        }

        /* Get destroy flags if provided */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_DESTROY_FLAGS, DATA_TYPE_UINT16, &flags, NULL)
            != 0) {
                be_print_err(gettext("be_destroy: failed to lookup "
                    "BE_ATTR_DESTROY_FLAGS attribute\n"));
                return (BE_ERR_INVAL);
        }

        dd.destroy_snaps = flags & BE_DESTROY_FLAG_SNAPSHOTS;
        dd.force_unmount = flags & BE_DESTROY_FLAG_FORCE_UNMOUNT;

        /* Find which zpool obe_name lives in */
        if ((zret = zpool_iter(g_zfs, be_find_zpool_callback, &bt)) == 0) {
                be_print_err(gettext("be_destroy: failed to find zpool "
                    "for BE (%s)\n"), bt.obe_name);
                return (BE_ERR_BE_NOENT);
        } else if (zret < 0) {
                be_print_err(gettext("be_destroy: zpool_iter failed: %s\n"),
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /* Generate string for obe_name's root dataset */
        if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
            sizeof (obe_root_ds))) != BE_SUCCESS) {
                be_print_err(gettext("%s: failed to get BE container dataset "
                    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
                return (ret);
        }
        bt.obe_root_ds = obe_root_ds;

        if (getzoneid() != GLOBAL_ZONEID) {
                if (!be_zone_compare_uuids(bt.obe_root_ds)) {
                        if (be_is_active_on_boot(bt.obe_name)) {
                                be_print_err(gettext("be_destroy: destroying "
                                    "active zone root dataset from non-active "
                                    "global BE is not supported\n"));
                                return (BE_ERR_NOTSUP);
                        }
                }
        }

        /*
         * Detect if the BE to destroy has the 'active on boot' property set.
         * If so, set the 'active on boot' property on the the 'active' BE.
         */
        if (be_is_active_on_boot(bt.obe_name)) {
                if ((ret = be_activate_current_be()) != BE_SUCCESS) {
                        be_print_err(gettext("be_destroy: failed to "
                            "make the current BE 'active on boot'\n"));
                        return (ret);
                }
        }

        /*
         * Detect if the BE to destroy is referenced in the pool's nextboot
         * field, and unset it if so.
         */
        if (getzoneid() == GLOBAL_ZONEID) {
                char *nextboot = NULL;

                if (lzbe_get_boot_device(bt.obe_zpool, &nextboot) == 0 &&
                    nextboot != NULL && strcmp(nextboot, bt.obe_root_ds) == 0) {
                        if (lzbe_set_boot_device(bt.obe_zpool,
                            lzbe_add, "") != 0) {
                                be_print_err(gettext("be_destroy: failed to "
                                    "remove temporary activation for "
                                    "dataset %s on pool %s\n"),
                                    bt.obe_root_ds, bt.obe_zpool);
                                free(nextboot);
                                return (BE_ERR_UNKNOWN);
                        }
                }
                free(nextboot);
        }

        /* Get handle to BE's root dataset */
        if ((zhp = zfs_open(g_zfs, bt.obe_root_ds, ZFS_TYPE_FILESYSTEM)) ==
            NULL) {
                be_print_err(gettext("be_destroy: failed to "
                    "open BE root dataset (%s): %s\n"), bt.obe_root_ds,
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /*
         * Check if BE has snapshots and BE_DESTROY_FLAG_SNAPSHOTS
         * is not set.
         */
        (void) zfs_iter_snapshots(zhp, B_FALSE, be_has_snapshot_callback,
            &bs_found);
        if (!dd.destroy_snaps && bs_found) {
                ZFS_CLOSE(zhp);
                return (BE_ERR_SS_EXISTS);
        }

        /* Get the UUID of the global BE */
        if (getzoneid() == GLOBAL_ZONEID) {
                if (be_get_uuid(zfs_get_name(zhp),
                    &dd.gz_be_uuid) != BE_SUCCESS) {
                        be_print_err(gettext("be_destroy: BE has no "
                        "UUID (%s)\n"), zfs_get_name(zhp));
                }
        }

        /*
         * If the global BE is mounted, make sure we've been given the
         * flag to forcibly unmount it.
         */
        if (zfs_is_mounted(zhp, &mp)) {
                if (!(dd.force_unmount)) {
                        be_print_err(gettext("be_destroy: "
                            "%s is currently mounted at %s, cannot destroy\n"),
                            bt.obe_name, mp != NULL ? mp : "<unknown>");

                        free(mp);
                        ZFS_CLOSE(zhp);
                        return (BE_ERR_MOUNTED);
                }
                free(mp);
        }

        /*
         * Destroy the non-global zone BE's if we are in the global zone
         * and there is a UUID associated with the global zone BE
         */
        if (getzoneid() == GLOBAL_ZONEID && !uuid_is_null(dd.gz_be_uuid)) {
                if ((ret = be_destroy_zones(bt.obe_name, bt.obe_root_ds, &dd))
                    != BE_SUCCESS) {
                        be_print_err(gettext("be_destroy: failed to "
                            "destroy one or more zones for BE %s\n"),
                            bt.obe_name);
                        goto done;
                }
        }

        /* Unmount the BE if it was mounted */
        if (zfs_is_mounted(zhp, NULL)) {
                if ((ret = _be_unmount(bt.obe_name, BE_UNMOUNT_FLAG_FORCE))
                    != BE_SUCCESS) {
                        be_print_err(gettext("be_destroy: "
                            "failed to unmount %s\n"), bt.obe_name);
                        ZFS_CLOSE(zhp);
                        return (ret);
                }
        }
        ZFS_CLOSE(zhp);

        /* Destroy this BE */
        if ((ret = _be_destroy((const char *)bt.obe_root_ds, &dd))
            != BE_SUCCESS) {
                goto done;
        }

        /* Remove BE's entry from the boot menu */
        if (getzoneid() == GLOBAL_ZONEID) {
                if ((ret = be_remove_menu(bt.obe_name, bt.obe_zpool, NULL))
                    != BE_SUCCESS) {
                        be_print_err(gettext("be_destroy: failed to "
                            "remove BE %s from the boot menu\n"),
                            bt.obe_root_ds);
                        goto done;
                }
        }

done:
        be_zfs_fini();

        return (ret);
}

/*
 * Function:    be_copy
 * Description: This function makes a copy of an existing BE.  If the original
 *              BE and the new BE are in the same pool, it uses zfs cloning to
 *              create the new BE, otherwise it does a physical copy.
 *              If the original BE name isn't provided, it uses the currently
 *              booted BE.  If the new BE name isn't provided, it creates an
 *              auto named BE and returns that name to the caller.
 * Parameters:
 *              be_attrs - pointer to nvlist_t of attributes being passed in.
 *                      The following attributes are used by this function:
 *
 *                      BE_ATTR_ORIG_BE_NAME            *optional
 *                      BE_ATTR_SNAP_NAME               *optional
 *                      BE_ATTR_NEW_BE_NAME             *optional
 *                      BE_ATTR_NEW_BE_POOL             *optional
 *                      BE_ATTR_NEW_BE_DESC             *optional
 *                      BE_ATTR_ZFS_PROPERTIES          *optional
 *                      BE_ATTR_POLICY                  *optional
 *
 *                      If the BE_ATTR_NEW_BE_NAME was not passed in, upon
 *                      successful BE creation, the following attribute values
 *                      will be returned to the caller by setting them in the
 *                      be_attrs parameter passed in:
 *
 *                      BE_ATTR_SNAP_NAME
 *                      BE_ATTR_NEW_BE_NAME
 * Return:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Public
 */
int
be_copy(nvlist_t *be_attrs)
{
        be_transaction_data_t   bt = { 0 };
        be_fs_list_data_t       fld = { 0 };
        zfs_handle_t    *zhp = NULL;
        zpool_handle_t  *zphp = NULL;
        nvlist_t        *zfs_props = NULL;
        uuid_t          uu = { 0 };
        uuid_t          parent_uu = { 0 };
        char            obe_root_ds[MAXPATHLEN];
        char            nbe_root_ds[MAXPATHLEN];
        char            obe_root_container[MAXPATHLEN];
        char            nbe_root_container[MAXPATHLEN];
        char            ss[MAXPATHLEN];
        char            *new_mp = NULL;
        char            *obe_name = NULL;
        boolean_t       autoname = B_FALSE;
        boolean_t       be_created = B_FALSE;
        int             i;
        int             zret;
        int             ret = BE_SUCCESS;
        struct be_defaults be_defaults;

        /* Initialize libzfs handle */
        if (!be_zfs_init())
                return (BE_ERR_INIT);

        /* Get original BE name */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_ORIG_BE_NAME, DATA_TYPE_STRING, &obe_name, NULL) != 0) {
                be_print_err(gettext("be_copy: failed to lookup "
                    "BE_ATTR_ORIG_BE_NAME attribute\n"));
                return (BE_ERR_INVAL);
        }

        if ((ret = be_find_current_be(&bt)) != BE_SUCCESS) {
                return (ret);
        }

        be_get_defaults(&be_defaults);

        /* If original BE name not provided, use current BE */
        if (obe_name != NULL) {
                bt.obe_name = obe_name;
                /* Validate original BE name */
                if (!be_valid_be_name(bt.obe_name)) {
                        be_print_err(gettext("be_copy: "
                            "invalid BE name %s\n"), bt.obe_name);
                        return (BE_ERR_INVAL);
                }
        }

        if (be_defaults.be_deflt_rpool_container) {
                if ((zphp = zpool_open(g_zfs, bt.obe_zpool)) == NULL) {
                        be_print_err(gettext("be_get_node_data: failed to "
                            "open rpool (%s): %s\n"), bt.obe_zpool,
                            libzfs_error_description(g_zfs));
                        return (zfs_err_to_be_err(g_zfs));
                }
                if (be_find_zpool_callback(zphp, &bt) == 0) {
                        return (BE_ERR_BE_NOENT);
                }
        } else {
                /* Find which zpool obe_name lives in */
                if ((zret = zpool_iter(g_zfs, be_find_zpool_callback, &bt)) ==
                    0) {
                        be_print_err(gettext("be_copy: failed to "
                            "find zpool for BE (%s)\n"), bt.obe_name);
                        return (BE_ERR_BE_NOENT);
                } else if (zret < 0) {
                        be_print_err(gettext("be_copy: "
                            "zpool_iter failed: %s\n"),
                            libzfs_error_description(g_zfs));
                        return (zfs_err_to_be_err(g_zfs));
                }
        }

        /* Get snapshot name of original BE if one was provided */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_SNAP_NAME, DATA_TYPE_STRING, &bt.obe_snap_name, NULL)
            != 0) {
                be_print_err(gettext("be_copy: failed to lookup "
                    "BE_ATTR_SNAP_NAME attribute\n"));
                return (BE_ERR_INVAL);
        }

        /* Get new BE name */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_NEW_BE_NAME, DATA_TYPE_STRING, &bt.nbe_name, NULL)
            != 0) {
                be_print_err(gettext("be_copy: failed to lookup "
                    "BE_ATTR_NEW_BE_NAME attribute\n"));
                return (BE_ERR_INVAL);
        }

        /* Get zpool name to create new BE in */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_NEW_BE_POOL, DATA_TYPE_STRING, &bt.nbe_zpool, NULL) != 0) {
                be_print_err(gettext("be_copy: failed to lookup "
                    "BE_ATTR_NEW_BE_POOL attribute\n"));
                return (BE_ERR_INVAL);
        }

        /* Get new BE's description if one was provided */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_NEW_BE_DESC, DATA_TYPE_STRING, &bt.nbe_desc, NULL) != 0) {
                be_print_err(gettext("be_copy: failed to lookup "
                    "BE_ATTR_NEW_BE_DESC attribute\n"));
                return (BE_ERR_INVAL);
        }

        /* Get BE policy to create this snapshot under */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_POLICY, DATA_TYPE_STRING, &bt.policy, NULL) != 0) {
                be_print_err(gettext("be_copy: failed to lookup "
                    "BE_ATTR_POLICY attribute\n"));
                return (BE_ERR_INVAL);
        }

        /*
         * Create property list for new BE root dataset.  If some
         * zfs properties were already provided by the caller, dup
         * that list.  Otherwise initialize a new property list.
         */
        if (nvlist_lookup_pairs(be_attrs, NV_FLAG_NOENTOK,
            BE_ATTR_ZFS_PROPERTIES, DATA_TYPE_NVLIST, &zfs_props, NULL)
            != 0) {
                be_print_err(gettext("be_copy: failed to lookup "
                    "BE_ATTR_ZFS_PROPERTIES attribute\n"));
                return (BE_ERR_INVAL);
        }
        if (zfs_props != NULL) {
                /* Make sure its a unique nvlist */
                if (!(zfs_props->nvl_nvflag & NV_UNIQUE_NAME) &&
                    !(zfs_props->nvl_nvflag & NV_UNIQUE_NAME_TYPE)) {
                        be_print_err(gettext("be_copy: ZFS property list "
                            "not unique\n"));
                        return (BE_ERR_INVAL);
                }

                /* Dup the list */
                if (nvlist_dup(zfs_props, &bt.nbe_zfs_props, 0) != 0) {
                        be_print_err(gettext("be_copy: "
                            "failed to dup ZFS property list\n"));
                        return (BE_ERR_NOMEM);
                }
        } else {
                /* Initialize new nvlist */
                if (nvlist_alloc(&bt.nbe_zfs_props, NV_UNIQUE_NAME, 0) != 0) {
                        be_print_err(gettext("be_copy: internal "
                            "error: out of memory\n"));
                        return (BE_ERR_NOMEM);
                }
        }

        /*
         * If an auto named BE is desired, it must be in the same
         * pool as the original BE.
         */
        if (bt.nbe_name == NULL && bt.nbe_zpool != NULL) {
                be_print_err(gettext("be_copy: cannot specify pool "
                    "name when creating an auto named BE\n"));
                ret = BE_ERR_INVAL;
                goto done;
        }

        /*
         * If the zpool name to create new BE in is not provided,
         * create the new BE in the original BE's pool.
         */
        if (bt.nbe_zpool == NULL)
                bt.nbe_zpool = bt.obe_zpool;

        /*
         * If new BE name provided, validate the BE name and then verify
         * that new BE name doesn't already exist in some pool.
         */
        if (bt.nbe_name != NULL) {
                /* Validate original BE name */
                if (!be_valid_be_name(bt.nbe_name)) {
                        be_print_err(gettext("be_copy: "
                            "invalid BE name %s\n"), bt.nbe_name);
                        ret = BE_ERR_INVAL;
                        goto done;
                }

                /* Verify it doesn't already exist */
                if (getzoneid() == GLOBAL_ZONEID) {
                        if ((zret = zpool_iter(g_zfs, be_exists_callback,
                            bt.nbe_name)) > 0) {
                                be_print_err(gettext("be_copy: BE (%s) already "
                                    "exists\n"), bt.nbe_name);
                                ret = BE_ERR_BE_EXISTS;
                                goto done;
                        } else if (zret < 0) {
                                be_print_err(gettext("be_copy: zpool_iter "
                                    "failed: %s\n"),
                                    libzfs_error_description(g_zfs));
                                ret = zfs_err_to_be_err(g_zfs);
                                goto done;
                        }
                } else {
                        if ((ret = be_make_root_ds(bt.nbe_zpool, bt.nbe_name,
                            nbe_root_ds, sizeof (nbe_root_ds))) != BE_SUCCESS) {
                                be_print_err(gettext("%s: failed to get BE "
                                    "container dataset for %s/%s\n"), __func__,
                                    bt.nbe_zpool, bt.nbe_name);
                                goto done;
                        }
                        if (zfs_dataset_exists(g_zfs, nbe_root_ds,
                            ZFS_TYPE_FILESYSTEM)) {
                                be_print_err(gettext("be_copy: BE (%s) already "
                                    "exists\n"), bt.nbe_name);
                                ret = BE_ERR_BE_EXISTS;
                                goto done;
                        }
                }
        } else {
                /*
                 * Generate auto named BE
                 */
                if ((bt.nbe_name = be_auto_be_name(bt.obe_name))
                    == NULL) {
                        be_print_err(gettext("be_copy: "
                            "failed to generate auto BE name\n"));
                        ret = BE_ERR_AUTONAME;
                        goto done;
                }

                autoname = B_TRUE;
        }

        /* Get root dataset names for obe_name and nbe_name */
        if ((ret = be_make_root_ds(bt.obe_zpool, bt.obe_name, obe_root_ds,
            sizeof (obe_root_ds))) != BE_SUCCESS) {
                be_print_err(gettext("%s: failed to get BE container dataset "
                    "for %s/%s\n"), __func__, bt.obe_zpool, bt.obe_name);
                goto done;
        }
        if ((ret = be_make_root_ds(bt.nbe_zpool, bt.nbe_name, nbe_root_ds,
            sizeof (nbe_root_ds))) != BE_SUCCESS) {
                be_print_err(gettext("%s: failed to get BE container dataset "
                    "for %s/%s\n"), __func__, bt.nbe_zpool, bt.nbe_name);
                goto done;
        }

        bt.obe_root_ds = obe_root_ds;
        bt.nbe_root_ds = nbe_root_ds;

        /*
         * If an existing snapshot name has been provided to create from,
         * verify that it exists for the original BE's root dataset.
         */
        if (bt.obe_snap_name != NULL) {

                /* Generate dataset name for snapshot to use. */
                (void) snprintf(ss, sizeof (ss), "%s@%s", bt.obe_root_ds,
                    bt.obe_snap_name);

                /* Verify snapshot exists */
                if (!zfs_dataset_exists(g_zfs, ss, ZFS_TYPE_SNAPSHOT)) {
                        be_print_err(gettext("be_copy: "
                            "snapshot does not exist (%s): %s\n"), ss,
                            libzfs_error_description(g_zfs));
                        ret = BE_ERR_SS_NOENT;
                        goto done;
                }
        } else {
                /*
                 * Else snapshot name was not provided, generate an
                 * auto named snapshot to use as its origin.
                 */
                if ((ret = _be_create_snapshot(bt.obe_name,
                    &bt.obe_snap_name, bt.policy)) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy: "
                            "failed to create auto named snapshot\n"));
                        goto done;
                }

                if (nvlist_add_string(be_attrs, BE_ATTR_SNAP_NAME,
                    bt.obe_snap_name) != 0) {
                        be_print_err(gettext("be_copy: "
                            "failed to add snap name to be_attrs\n"));
                        ret = BE_ERR_NOMEM;
                        goto done;
                }
        }

        /* Get handle to original BE's root dataset. */
        if ((zhp = zfs_open(g_zfs, bt.obe_root_ds, ZFS_TYPE_FILESYSTEM))
            == NULL) {
                be_print_err(gettext("be_copy: failed to "
                    "open BE root dataset (%s): %s\n"), bt.obe_root_ds,
                    libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                goto done;
        }

        /* If original BE is currently mounted, record its altroot. */
        if (zfs_is_mounted(zhp, &bt.obe_altroot) && bt.obe_altroot == NULL) {
                be_print_err(gettext("be_copy: failed to "
                    "get altroot of mounted BE %s: %s\n"),
                    bt.obe_name, libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                goto done;
        }

        if (strcmp(bt.obe_zpool, bt.nbe_zpool) == 0) {

                /* Do clone */

                /*
                 * Iterate through original BE's datasets and clone
                 * them to create new BE.  This call will end up closing
                 * the zfs handle passed in whether it succeeds for fails.
                 */
                if ((ret = be_clone_fs_callback(zhp, &bt)) != 0) {
                        zhp = NULL;
                        /* Creating clone BE failed */
                        if (!autoname || ret != BE_ERR_BE_EXISTS) {
                                be_print_err(gettext("be_copy: "
                                    "failed to clone new BE (%s) from "
                                    "orig BE (%s)\n"),
                                    bt.nbe_name, bt.obe_name);
                                ret = BE_ERR_CLONE;
                                goto done;
                        }

                        /*
                         * We failed to create the new BE because a BE with
                         * the auto-name we generated above has since come
                         * into existence.  Regenerate a new auto-name
                         * and retry.
                         */
                        for (i = 1; i < BE_AUTO_NAME_MAX_TRY; i++) {

                                /* Sleep 1 before retrying */
                                (void) sleep(1);

                                /* Generate new auto BE name */
                                free(bt.nbe_name);
                                if ((bt.nbe_name = be_auto_be_name(bt.obe_name))
                                    == NULL) {
                                        be_print_err(gettext("be_copy: "
                                            "failed to generate auto "
                                            "BE name\n"));
                                        ret = BE_ERR_AUTONAME;
                                        goto done;
                                }

                                /*
                                 * Regenerate string for new BE's
                                 * root dataset name
                                 */
                                if ((ret = be_make_root_ds(bt.nbe_zpool,
                                    bt.nbe_name, nbe_root_ds,
                                    sizeof (nbe_root_ds))) != BE_SUCCESS) {
                                        be_print_err(gettext(
                                            "%s: failed to get BE container "
                                            "dataset for %s/%s\n"), __func__,
                                            bt.nbe_zpool, bt.nbe_name);
                                        goto done;
                                }
                                bt.nbe_root_ds = nbe_root_ds;

                                /*
                                 * Get handle to original BE's root dataset.
                                 */
                                if ((zhp = zfs_open(g_zfs, bt.obe_root_ds,
                                    ZFS_TYPE_FILESYSTEM)) == NULL) {
                                        be_print_err(gettext("be_copy: "
                                            "failed to open BE root dataset "
                                            "(%s): %s\n"), bt.obe_root_ds,
                                            libzfs_error_description(g_zfs));
                                        ret = zfs_err_to_be_err(g_zfs);
                                        goto done;
                                }

                                /*
                                 * Try to clone the BE again.  This
                                 * call will end up closing the zfs
                                 * handle passed in whether it
                                 * succeeds or fails.
                                 */
                                ret = be_clone_fs_callback(zhp, &bt);
                                zhp = NULL;
                                if (ret == 0) {
                                        break;
                                } else if (ret != BE_ERR_BE_EXISTS) {
                                        be_print_err(gettext("be_copy: "
                                            "failed to clone new BE "
                                            "(%s) from orig BE (%s)\n"),
                                            bt.nbe_name, bt.obe_name);
                                        ret = BE_ERR_CLONE;
                                        goto done;
                                }
                        }

                        /*
                         * If we've exhausted the maximum number of
                         * tries, free the auto BE name and return
                         * error.
                         */
                        if (i == BE_AUTO_NAME_MAX_TRY) {
                                be_print_err(gettext("be_copy: failed "
                                    "to create unique auto BE name\n"));
                                free(bt.nbe_name);
                                bt.nbe_name = NULL;
                                ret = BE_ERR_AUTONAME;
                                goto done;
                        }
                }
                zhp = NULL;

        } else {

                /* Do copy (i.e. send BE datasets via zfs_send/recv) */

                /*
                 * Verify BE container dataset in nbe_zpool exists.
                 * If not, create it.
                 */
                if (!be_create_container_ds(bt.nbe_zpool)) {
                        ret = BE_ERR_CREATDS;
                        goto done;
                }

                /*
                 * Iterate through original BE's datasets and send
                 * them to the other pool.  This call will end up closing
                 * the zfs handle passed in whether it succeeds or fails.
                 */
                if ((ret = be_send_fs_callback(zhp, &bt)) != 0) {
                        be_print_err(gettext("be_copy: failed to "
                            "send BE (%s) to pool (%s)\n"), bt.obe_name,
                            bt.nbe_zpool);
                        ret = BE_ERR_COPY;
                        zhp = NULL;
                        goto done;
                }
                zhp = NULL;
        }

        /*
         * Set flag to note that the dataset(s) for the new BE have been
         * successfully created so that if a failure happens from this point
         * on, we know to cleanup these datasets.
         */
        be_created = B_TRUE;

        /*
         * Validate that the new BE is mountable.
         * Do not attempt to mount non-global zone datasets
         * since they are not cloned yet.
         */
        if ((ret = _be_mount(bt.nbe_name, &new_mp, BE_MOUNT_FLAG_NO_ZONES))
            != BE_SUCCESS) {
                be_print_err(gettext("be_copy: failed to "
                    "mount newly created BE\n"));
                (void) _be_unmount(bt.nbe_name, 0);
                goto done;
        }

        /* Set UUID for new BE */
        if (getzoneid() == GLOBAL_ZONEID) {
                if (be_set_uuid(bt.nbe_root_ds) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy: failed to "
                            "set uuid for new BE\n"));
                }
        } else {
                if ((ret = be_zone_get_parent_uuid(bt.obe_root_ds,
                    &parent_uu)) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy: failed to get "
                            "parentbe uuid from orig BE\n"));
                        ret = BE_ERR_ZONE_NO_PARENTBE;
                        goto done;
                } else if ((ret = be_zone_set_parent_uuid(bt.nbe_root_ds,
                    parent_uu)) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy: failed to set "
                            "parentbe uuid for newly created BE\n"));
                        goto done;
                }
        }

        /*
         * Process zones outside of the private BE namespace.
         * This has to be done here because we need the uuid set in the
         * root dataset of the new BE. The uuid is use to set the parentbe
         * property for the new zones datasets.
         */
        if (getzoneid() == GLOBAL_ZONEID &&
            be_get_uuid(bt.obe_root_ds, &uu) == BE_SUCCESS) {
                if ((ret = be_copy_zones(bt.obe_name, bt.obe_root_ds,
                    bt.nbe_root_ds)) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy: failed to process "
                            "zones\n"));
                        goto done;
                }
        }

        /*
         * Generate a list of file systems from the original BE that are
         * legacy mounted.  We use this list to determine which entries in
         * vfstab we need to update for the new BE we've just created.
         */
        if ((ret = be_get_legacy_fs(bt.obe_name, bt.obe_root_ds, NULL, NULL,
            &fld)) != BE_SUCCESS) {
                be_print_err(gettext("be_copy: failed to "
                    "get legacy mounted file system list for %s\n"),
                    bt.obe_name);
                goto done;
        }

        /*
         * Update new BE's vfstab.
         */

        if ((ret = be_make_root_container_ds(bt.obe_zpool, obe_root_container,
            sizeof (obe_root_container))) != BE_SUCCESS) {
                be_print_err(gettext("%s: failed to get BE container dataset "
                    "for %s\n"), __func__, bt.obe_zpool);
                goto done;
        }
        if ((ret = be_make_root_container_ds(bt.nbe_zpool, nbe_root_container,
            sizeof (nbe_root_container))) != BE_SUCCESS) {
                be_print_err(gettext("%s: failed to get BE container dataset "
                    "for %s\n"), __func__, bt.nbe_zpool);
                goto done;
        }

        if ((ret = be_update_vfstab(bt.nbe_name, obe_root_container,
            nbe_root_container, &fld, new_mp)) != BE_SUCCESS) {
                be_print_err(gettext("be_copy: failed to "
                    "update new BE's vfstab (%s)\n"), bt.nbe_name);
                goto done;
        }

        /* Unmount the new BE */
        if ((ret = _be_unmount(bt.nbe_name, 0)) != BE_SUCCESS) {
                be_print_err(gettext("be_copy: failed to "
                    "unmount newly created BE\n"));
                goto done;
        }

        /*
         * Add boot menu entry for newly created clone
         */
        if (getzoneid() == GLOBAL_ZONEID &&
            (ret = be_append_menu(bt.nbe_name, bt.nbe_zpool,
            NULL, bt.obe_root_ds, bt.nbe_desc)) != BE_SUCCESS) {
                be_print_err(gettext("be_copy: failed to "
                    "add BE (%s) to boot menu\n"), bt.nbe_name);
                goto done;
        }

        /*
         * If we succeeded in creating an auto named BE, set its policy
         * type and return the auto generated name to the caller by storing
         * it in the nvlist passed in by the caller.
         */
        if (autoname) {
                /* Get handle to new BE's root dataset. */
                if ((zhp = zfs_open(g_zfs, bt.nbe_root_ds,
                    ZFS_TYPE_FILESYSTEM)) == NULL) {
                        be_print_err(gettext("be_copy: failed to "
                            "open BE root dataset (%s): %s\n"), bt.nbe_root_ds,
                            libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        goto done;
                }

                /*
                 * Set the policy type property into the new BE's root dataset
                 */
                if (bt.policy == NULL) {
                        /* If no policy type provided, use default type */
                        bt.policy = be_default_policy();
                }

                if (zfs_prop_set(zhp, BE_POLICY_PROPERTY, bt.policy) != 0) {
                        be_print_err(gettext("be_copy: failed to "
                            "set BE policy for %s: %s\n"), bt.nbe_name,
                            libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        goto done;
                }

                /*
                 * Return the auto generated name to the caller
                 */
                if (bt.nbe_name) {
                        if (nvlist_add_string(be_attrs, BE_ATTR_NEW_BE_NAME,
                            bt.nbe_name) != 0) {
                                be_print_err(gettext("be_copy: failed to "
                                    "add snap name to be_attrs\n"));
                        }
                }
        }

done:
        ZFS_CLOSE(zhp);
        be_free_fs_list(&fld);

        nvlist_free(bt.nbe_zfs_props);

        free(bt.obe_altroot);
        free(new_mp);

        /*
         * If a failure occurred and we already created the datasets for
         * the new boot environment, destroy them.
         */
        if (ret != BE_SUCCESS && be_created) {
                be_destroy_data_t       cdd = { 0 };

                cdd.force_unmount = B_TRUE;

                be_print_err(gettext("be_copy: "
                    "destroying partially created boot environment\n"));

                if (getzoneid() == GLOBAL_ZONEID && be_get_uuid(bt.nbe_root_ds,
                    &cdd.gz_be_uuid) == 0)
                        (void) be_destroy_zones(bt.nbe_name, bt.nbe_root_ds,
                            &cdd);

                (void) _be_destroy(bt.nbe_root_ds, &cdd);
        }

        be_zfs_fini();

        return (ret);
}

/* ******************************************************************** */
/*                      Semi-Private Functions                          */
/* ******************************************************************** */

/*
 * Function:    be_find_zpool_callback
 * Description: Callback function used to find the pool that a BE lives in.
 * Parameters:
 *              zlp - zpool_handle_t pointer for the current pool being
 *                      looked at.
 *              data - be_transaction_data_t pointer providing information
 *                      about the BE that's being searched for.
 *                      This function uses the obe_name member of this
 *                      parameter to use as the BE name to search for.
 *                      Upon successfully locating the BE, it populates
 *                      obe_zpool with the pool name that the BE is found in.
 * Returns:
 *              1 - BE exists in this pool.
 *              0 - BE does not exist in this pool.
 * Scope:
 *              Semi-private (library wide use only)
 */
int
be_find_zpool_callback(zpool_handle_t *zlp, void *data)
{
        be_transaction_data_t   *bt = data;
        const char              *zpool =  zpool_get_name(zlp);
        char                    be_root_ds[MAXPATHLEN];
        int                     ret = 0;

        /*
         * Generate string for the BE's root dataset
         */
        if (be_make_root_ds(zpool, bt->obe_name, be_root_ds,
            sizeof (be_root_ds)) != BE_SUCCESS) {
                goto out;
        }

        /*
         * Check if dataset exists
         */
        if (zfs_dataset_exists(g_zfs, be_root_ds, ZFS_TYPE_FILESYSTEM)) {
                /* BE's root dataset exists in zpool */
                bt->obe_zpool = strdup(zpool);
                ret = 1;
        }

out:
        zpool_close(zlp);
        return (ret);
}

/*
 * Function:    be_exists_callback
 * Description: Callback function used to find out if a BE exists.
 * Parameters:
 *              zlp - zpool_handle_t pointer to the current pool being
 *                      looked at.
 *              data - BE name to look for.
 * Return:
 *              1 - BE exists in this pool.
 *              0 - BE does not exist in this pool.
 * Scope:
 *              Semi-private (library wide use only)
 */
int
be_exists_callback(zpool_handle_t *zlp, void *data)
{
        const char      *zpool = zpool_get_name(zlp);
        char            *be_name = data;
        char            be_root_ds[MAXPATHLEN];
        int             ret = 0;

        /*
         * Generate string for the BE's root dataset
         */
        if (be_make_root_ds(zpool, be_name, be_root_ds,
            sizeof (be_root_ds)) != BE_SUCCESS) {
                goto out;
        }

        /*
         * Check if dataset exists
         */
        if (zfs_dataset_exists(g_zfs, be_root_ds, ZFS_TYPE_FILESYSTEM)) {
                /* BE's root dataset exists in zpool */
                ret = 1;
        }

out:
        zpool_close(zlp);
        return (ret);
}

/*
 * Function:    be_has_snapshots_callback
 * Description: Callback function used to find out if a BE has snapshots.
 * Parameters:
 *              zlp - zpool_handle_t pointer to the current pool being
 *                      looked at.
 *              data - be_snap_found_t pointer.
 * Return:
 *              1 - BE has no snapshots.
 *              0 - BE has snapshots.
 * Scope:
 *              Private
 */
static int
be_has_snapshot_callback(zfs_handle_t *zhp, void *data)
{
        boolean_t *bs = data;
        if (zfs_get_name(zhp) == NULL) {
                zfs_close(zhp);
                return (1);
        }
        *bs = B_TRUE;
        zfs_close(zhp);
        return (0);
}

/*
 * Function:    be_set_uuid
 * Description: This function generates a uuid, unparses it into
 *              string representation, and sets that string into
 *              a zfs user property for a root dataset of a BE.
 *              The name of the user property used to store the
 *              uuid is org.opensolaris.libbe:uuid
 *
 * Parameters:
 *              root_ds - Root dataset of the BE to set a uuid on.
 * Return:
 *              be_errno_t - Failure
 *              BE_SUCCESS - Success
 * Scope:
 *              Semi-private (library wide ues only)
 */
int
be_set_uuid(char *root_ds)
{
        zfs_handle_t    *zhp = NULL;
        uuid_t          uu = { 0 };
        char            uu_string[UUID_PRINTABLE_STRING_LENGTH] = { 0 };
        int             ret = BE_SUCCESS;

        /* Generate a UUID and unparse it into string form */
        uuid_generate(uu);
        if (uuid_is_null(uu) != 0) {
                be_print_err(gettext("be_set_uuid: failed to "
                    "generate uuid\n"));
                return (BE_ERR_GEN_UUID);
        }
        uuid_unparse(uu, uu_string);

        /* Get handle to the BE's root dataset. */
        if ((zhp = zfs_open(g_zfs, root_ds, ZFS_TYPE_FILESYSTEM)) == NULL) {
                be_print_err(gettext("be_set_uuid: failed to "
                    "open BE root dataset (%s): %s\n"), root_ds,
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /* Set uuid property for the BE */
        if (zfs_prop_set(zhp, BE_UUID_PROPERTY, uu_string) != 0) {
                be_print_err(gettext("be_set_uuid: failed to "
                    "set uuid property for BE: %s\n"),
                    libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
        }

        ZFS_CLOSE(zhp);

        return (ret);
}

/*
 * Function:    be_get_uuid
 * Description: This function gets the uuid string from a BE root
 *              dataset, parses it into internal format, and returns
 *              it the caller via a reference pointer passed in.
 *
 * Parameters:
 *              rootds - Root dataset of the BE to get the uuid from.
 *              uu - reference pointer to a uuid_t to return uuid in.
 * Return:
 *              be_errno_t - Failure
 *              BE_SUCCESS - Success
 * Scope:
 *              Semi-private (library wide use only)
 */
int
be_get_uuid(const char *root_ds, uuid_t *uu)
{
        zfs_handle_t    *zhp = NULL;
        nvlist_t        *userprops = NULL;
        nvlist_t        *propname = NULL;
        char            *uu_string = NULL;
        int             ret = BE_SUCCESS;

        /* Get handle to the BE's root dataset. */
        if ((zhp = zfs_open(g_zfs, root_ds, ZFS_TYPE_FILESYSTEM)) == NULL) {
                be_print_err(gettext("be_get_uuid: failed to "
                    "open BE root dataset (%s): %s\n"), root_ds,
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /* Get user properties for BE's root dataset */
        if ((userprops = zfs_get_user_props(zhp)) == NULL) {
                be_print_err(gettext("be_get_uuid: failed to "
                    "get user properties for BE root dataset (%s): %s\n"),
                    root_ds, libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                goto done;
        }

        /* Get UUID string from BE's root dataset user properties */
        if (nvlist_lookup_nvlist(userprops, BE_UUID_PROPERTY, &propname) != 0 ||
            nvlist_lookup_string(propname, ZPROP_VALUE, &uu_string) != 0) {
                /*
                 * This probably just means that the BE is simply too old
                 * to have a uuid or that we haven't created a uuid for
                 * this BE yet.
                 */
                be_print_err(gettext("be_get_uuid: failed to "
                    "get uuid property from BE root dataset user "
                    "properties.\n"));
                ret = BE_ERR_NO_UUID;
                goto done;
        }
        /* Parse uuid string into internal format */
        if (uuid_parse(uu_string, *uu) != 0 || uuid_is_null(*uu)) {
                be_print_err(gettext("be_get_uuid: failed to "
                    "parse uuid\n"));
                ret = BE_ERR_PARSE_UUID;
                goto done;
        }

done:
        ZFS_CLOSE(zhp);
        return (ret);
}

/* ******************************************************************** */
/*                      Private Functions                               */
/* ******************************************************************** */

/*
 * Function:    _be_destroy
 * Description: Destroy a BE and all of its children datasets and snapshots.
 *              This function is called for both global BEs and non-global BEs.
 *              The root dataset of either the global BE or non-global BE to be
 *              destroyed is passed in.
 * Parameters:
 *              root_ds - pointer to the name of the root dataset of the
 *                      BE to destroy.
 *              dd - pointer to a be_destroy_data_t structure.
 *
 * Return:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
static int
_be_destroy(const char *root_ds, be_destroy_data_t *dd)
{
        zfs_handle_t    *zhp = NULL;
        char            origin[MAXPATHLEN];
        char            parent[MAXPATHLEN];
        char            *snap = NULL;
        boolean_t       has_origin = B_FALSE;
        int             ret = BE_SUCCESS;

        /* Get handle to BE's root dataset */
        if ((zhp = zfs_open(g_zfs, root_ds, ZFS_TYPE_FILESYSTEM)) ==
            NULL) {
                be_print_err(gettext("be_destroy: failed to "
                    "open BE root dataset (%s): %s\n"), root_ds,
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /*
         * Demote this BE in case it has dependent clones.  This call
         * will end up closing the zfs handle passed in whether it
         * succeeds or fails.
         */
        if (be_demote_callback(zhp, NULL) != 0) {
                be_print_err(gettext("be_destroy: "
                    "failed to demote BE %s\n"), root_ds);
                return (BE_ERR_DEMOTE);
        }

        /* Get handle to BE's root dataset */
        if ((zhp = zfs_open(g_zfs, root_ds, ZFS_TYPE_FILESYSTEM)) ==
            NULL) {
                be_print_err(gettext("be_destroy: failed to "
                    "open BE root dataset (%s): %s\n"), root_ds,
                    libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /*
         * Get the origin of this BE's root dataset.  This will be used
         * later to destroy the snapshots originally used to create this BE.
         */
        if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, sizeof (origin), NULL,
            NULL, 0, B_FALSE) == 0) {
                (void) strlcpy(parent, origin, sizeof (parent));
                if (be_get_snap(parent, &snap) != BE_SUCCESS) {
                        ZFS_CLOSE(zhp);
                        be_print_err(gettext("be_destroy: failed to "
                            "get snapshot name from origin %s\n"), origin);
                        return (BE_ERR_INVAL);
                }
                has_origin = B_TRUE;
        }

        /*
         * Destroy the BE's root and its hierarchical children.  This call
         * will end up closing the zfs handle passed in whether it succeeds
         * or fails.
         */
        if (be_destroy_callback(zhp, dd) != 0) {
                be_print_err(gettext("be_destroy: failed to "
                    "destroy BE %s\n"), root_ds);
                ret = zfs_err_to_be_err(g_zfs);
                return (ret);
        }

        /* If BE has an origin */
        if (has_origin) {

                /*
                 * If origin snapshot doesn't have any other
                 * dependents, delete the origin.
                 */
                if ((zhp = zfs_open(g_zfs, origin, ZFS_TYPE_SNAPSHOT)) ==
                    NULL) {
                        be_print_err(gettext("be_destroy: failed to "
                            "open BE's origin (%s): %s\n"), origin,
                            libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        return (ret);
                }

                /* If origin has dependents, don't delete it. */
                if (zfs_prop_get_int(zhp, ZFS_PROP_NUMCLONES) != 0) {
                        ZFS_CLOSE(zhp);
                        return (ret);
                }
                ZFS_CLOSE(zhp);

                /* Get handle to BE's parent's root dataset */
                if ((zhp = zfs_open(g_zfs, parent, ZFS_TYPE_FILESYSTEM)) ==
                    NULL) {
                        be_print_err(gettext("be_destroy: failed to "
                            "open BE's parent root dataset (%s): %s\n"), parent,
                            libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        return (ret);
                }

                /* Destroy the snapshot origin used to create this BE. */
                /*
                 * The boolean set to B_FALSE and passed to zfs_destroy_snaps()
                 * tells zfs to process and destroy the snapshots now.
                 * Otherwise the call will potentially return where the
                 * snapshot isn't actually destroyed yet, and ZFS is waiting
                 * until all the references to the snapshot have been
                 * released before actually destroying the snapshot.
                 */
                if (zfs_destroy_snaps(zhp, snap, B_FALSE) != 0) {
                        be_print_err(gettext("be_destroy: failed to "
                            "destroy original snapshots used to create "
                            "BE: %s\n"), libzfs_error_description(g_zfs));

                        /*
                         * If a failure happened because a clone exists,
                         * don't return a failure to the user.  Above, we're
                         * only checking that the root dataset's origin
                         * snapshot doesn't have dependent clones, but its
                         * possible that a subordinate dataset origin snapshot
                         * has a clone.  We really need to check for that
                         * before trying to destroy the origin snapshot.
                         */
                        if (libzfs_errno(g_zfs) != EZFS_EXISTS) {
                                ret = zfs_err_to_be_err(g_zfs);
                                ZFS_CLOSE(zhp);
                                return (ret);
                        }
                }
                ZFS_CLOSE(zhp);
        }

        return (ret);
}

/*
 * Function:    be_destroy_zones
 * Description: Find valid zone's and call be_destroy_zone_roots to destroy its
 *              corresponding dataset and all of its children datasets
 *              and snapshots.
 * Parameters:
 *              be_name - name of global boot environment being destroyed
 *              be_root_ds - root dataset of global boot environment being
 *                      destroyed.
 *              dd - be_destroy_data_t pointer
 * Return:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 *
 * NOTES - Requires that the BE being deleted has no dependent BEs.  If it
 *         does, the destroy will fail.
 */
static int
be_destroy_zones(char *be_name, char *be_root_ds, be_destroy_data_t *dd)
{
        int             i;
        int             ret = BE_SUCCESS;
        int             force_umnt = BE_UNMOUNT_FLAG_NULL;
        char            *zonepath = NULL;
        char            *zonename = NULL;
        char            *zonepath_ds = NULL;
        char            *mp = NULL;
        zoneList_t      zlist = NULL;
        zoneBrandList_t *brands = NULL;
        zfs_handle_t    *zhp = NULL;

        /* If zones are not implemented, then get out. */
        if (!z_zones_are_implemented()) {
                return (BE_SUCCESS);
        }

        /* Get list of supported brands */
        if ((brands = be_get_supported_brandlist()) == NULL) {
                be_print_err(gettext("be_destroy_zones: "
                    "no supported brands\n"));
                return (BE_SUCCESS);
        }

        /* Get handle to BE's root dataset */
        if ((zhp = zfs_open(g_zfs, be_root_ds, ZFS_TYPE_FILESYSTEM)) ==
            NULL) {
                be_print_err(gettext("be_destroy_zones: failed to "
                    "open BE root dataset (%s): %s\n"), be_root_ds,
                    libzfs_error_description(g_zfs));
                z_free_brand_list(brands);
                return (zfs_err_to_be_err(g_zfs));
        }

        /*
         * If the global BE is not mounted, we must mount it here to
         * gather data about the non-global zones in it.
         */
        if (!zfs_is_mounted(zhp, &mp)) {
                if ((ret = _be_mount(be_name, &mp,
                    BE_MOUNT_FLAG_NO_ZONES)) != BE_SUCCESS) {
                        be_print_err(gettext("be_destroy_zones: failed to "
                            "mount the BE (%s) for zones processing.\n"),
                            be_name);
                        ZFS_CLOSE(zhp);
                        z_free_brand_list(brands);
                        return (ret);
                }
        }
        ZFS_CLOSE(zhp);

        z_set_zone_root(mp);
        free(mp);

        /* Get list of supported zones. */
        if ((zlist = z_get_nonglobal_zone_list_by_brand(brands)) == NULL) {
                z_free_brand_list(brands);
                return (BE_SUCCESS);
        }

        /* Unmount the BE before destroying the zones in it. */
        if (dd->force_unmount)
                force_umnt = BE_UNMOUNT_FLAG_FORCE;
        if ((ret = _be_unmount(be_name, force_umnt)) != BE_SUCCESS) {
                be_print_err(gettext("be_destroy_zones: failed to "
                    "unmount the BE (%s)\n"), be_name);
                goto done;
        }

        /* Iterate through the zones and destroy them. */
        for (i = 0; (zonename = z_zlist_get_zonename(zlist, i)) != NULL; i++) {

                /* Skip zones that aren't at least installed */
                if (z_zlist_get_current_state(zlist, i) < ZONE_STATE_INSTALLED)
                        continue;

                zonepath = z_zlist_get_zonepath(zlist, i);

                /*
                 * Get the dataset of this zonepath.  If its not
                 * a dataset, skip it.
                 */
                if ((zonepath_ds = be_get_ds_from_dir(zonepath)) == NULL)
                        continue;

                /*
                 * Check if this zone is supported based on the
                 * dataset of its zonepath.
                 */
                if (!be_zone_supported(zonepath_ds)) {
                        free(zonepath_ds);
                        continue;
                }

                /* Find the zone BE root datasets for this zone. */
                if ((ret = be_destroy_zone_roots(zonepath_ds, dd))
                    != BE_SUCCESS) {
                        be_print_err(gettext("be_destroy_zones: failed to "
                            "find and destroy zone roots for zone %s\n"),
                            zonename);
                        free(zonepath_ds);
                        goto done;
                }
                free(zonepath_ds);
        }

done:
        z_free_brand_list(brands);
        z_free_zone_list(zlist);

        return (ret);
}

/*
 * Function:    be_destroy_zone_roots
 * Description: This function will open the zone's root container dataset
 *              and iterate the datasets within, looking for roots that
 *              belong to the given global BE and destroying them.
 *              If no other zone roots remain in the zone's root container
 *              dataset, the function will destroy it and the zone's
 *              zonepath dataset as well.
 * Parameters:
 *              zonepath_ds - pointer to zone's zonepath dataset.
 *              dd - pointer to a linked destroy data.
 * Returns:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
static int
be_destroy_zone_roots(char *zonepath_ds, be_destroy_data_t *dd)
{
        zfs_handle_t    *zhp;
        char            zone_container_ds[MAXPATHLEN];
        int             ret = BE_SUCCESS;

        /* Generate string for the root container dataset for this zone. */
        if ((ret = be_make_container_ds(zonepath_ds, zone_container_ds,
            sizeof (zone_container_ds))) != BE_SUCCESS) {
                be_print_err(gettext("%s: failed to get BE container dataset "
                    "for %s\n"), __func__, zonepath_ds);
                return (ret);
        }

        /* Get handle to this zone's root container dataset. */
        if ((zhp = zfs_open(g_zfs, zone_container_ds, ZFS_TYPE_FILESYSTEM))
            == NULL) {
                be_print_err(gettext("be_destroy_zone_roots: failed to "
                    "open zone root container dataset (%s): %s\n"),
                    zone_container_ds, libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /*
         * Iterate through all of this zone's BEs, destroying the ones
         * that belong to the parent global BE.
         */
        if ((ret = zfs_iter_filesystems(zhp, be_destroy_zone_roots_callback,
            dd)) != 0) {
                be_print_err(gettext("be_destroy_zone_roots: failed to "
                    "destroy zone roots under zonepath dataset %s: %s\n"),
                    zonepath_ds, libzfs_error_description(g_zfs));
                ZFS_CLOSE(zhp);
                return (ret);
        }
        ZFS_CLOSE(zhp);

        /* Get handle to this zone's root container dataset. */
        if ((zhp = zfs_open(g_zfs, zone_container_ds, ZFS_TYPE_FILESYSTEM))
            == NULL) {
                be_print_err(gettext("be_destroy_zone_roots: failed to "
                    "open zone root container dataset (%s): %s\n"),
                    zone_container_ds, libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /*
         * If there are no more zone roots in this zone's root container,
         * dataset, destroy it and the zonepath dataset as well.
         */
        if (zfs_iter_filesystems(zhp, be_zone_root_exists_callback, NULL)
            == 0) {
                /* Destroy the zone root container dataset */
                if (zfs_unmount(zhp, NULL, MS_FORCE) != 0 ||
                    zfs_destroy(zhp, B_FALSE) != 0) {
                        be_print_err(gettext("be_destroy_zone_roots: failed to "
                            "destroy zone root container dataset (%s): %s\n"),
                            zone_container_ds, libzfs_error_description(g_zfs));
                        goto done;
                }
                ZFS_CLOSE(zhp);

                /* Get handle to zonepath dataset */
                if ((zhp = zfs_open(g_zfs, zonepath_ds, ZFS_TYPE_FILESYSTEM))
                    == NULL) {
                        be_print_err(gettext("be_destroy_zone_roots: failed to "
                            "open zonepath dataset (%s): %s\n"),
                            zonepath_ds, libzfs_error_description(g_zfs));
                        goto done;
                }

                /* Destroy zonepath dataset */
                if (zfs_unmount(zhp, NULL, MS_FORCE) != 0 ||
                    zfs_destroy(zhp, B_FALSE) != 0) {
                        be_print_err(gettext("be_destroy_zone_roots: "
                            "failed to destroy zonepath dataest %s: %s\n"),
                            zonepath_ds, libzfs_error_description(g_zfs));
                        goto done;
                }
        }

done:
        ZFS_CLOSE(zhp);
        return (ret);
}

/*
 * Function:    be_destroy_zone_roots_callback
 * Description: This function is used as a callback to iterate over all of
 *              a zone's root datasets, finding the one's that
 *              correspond to the current BE. The name's
 *              of the zone root datasets are then destroyed by _be_destroy().
 * Parameters:
 *              zhp - zfs_handle_t pointer to current dataset being processed
 *              data - be_destroy_data_t pointer
 * Returns:
 *              0 - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
static int
be_destroy_zone_roots_callback(zfs_handle_t *zhp, void *data)
{
        be_destroy_data_t       *dd = data;
        uuid_t                  parent_uuid = { 0 };
        int                     ret = 0;

        if (be_zone_get_parent_uuid(zfs_get_name(zhp), &parent_uuid)
            != BE_SUCCESS) {
                be_print_err(gettext("be_destroy_zone_roots_callback: "
                    "could not get parentuuid for zone root dataset %s\n"),
                    zfs_get_name(zhp));
                ZFS_CLOSE(zhp);
                return (0);
        }

        if (uuid_compare(dd->gz_be_uuid, parent_uuid) == 0) {
                /*
                 * Found a zone root dataset belonging to the parent
                 * BE being destroyed.  Destroy this zone BE.
                 */
                if ((ret = _be_destroy(zfs_get_name(zhp), dd)) != BE_SUCCESS) {
                        be_print_err(gettext("be_destroy_zone_root_callback: "
                            "failed to destroy zone root %s\n"),
                            zfs_get_name(zhp));
                        ZFS_CLOSE(zhp);
                        return (ret);
                }
        }
        ZFS_CLOSE(zhp);

        return (ret);
}

/*
 * Function:    be_copy_zones
 * Description: Find valid zones and clone them to create their
 *              corresponding datasets for the BE being created.
 * Parameters:
 *              obe_name - name of source global BE being copied.
 *              obe_root_ds - root dataset of source global BE being copied.
 *              nbe_root_ds - root dataset of target global BE.
 * Return:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
static int
be_copy_zones(char *obe_name, char *obe_root_ds, char *nbe_root_ds)
{
        int             i, num_retries;
        int             ret = BE_SUCCESS;
        int             iret = 0;
        char            *zonename = NULL;
        char            *zonepath = NULL;
        char            *zone_be_name = NULL;
        char            *temp_mntpt = NULL;
        char            *new_zone_be_name = NULL;
        char            zoneroot[MAXPATHLEN];
        char            zoneroot_ds[MAXPATHLEN];
        char            zone_container_ds[MAXPATHLEN];
        char            new_zoneroot_ds[MAXPATHLEN];
        char            ss[MAXPATHLEN];
        uuid_t          uu = { 0 };
        char            uu_string[UUID_PRINTABLE_STRING_LENGTH] = { 0 };
        be_transaction_data_t bt = { 0 };
        zfs_handle_t    *obe_zhp = NULL;
        zfs_handle_t    *nbe_zhp = NULL;
        zfs_handle_t    *z_zhp = NULL;
        zoneList_t      zlist = NULL;
        zoneBrandList_t *brands = NULL;
        boolean_t       mounted_here = B_FALSE;
        char            *snap_name = NULL;

        /* If zones are not implemented, then get out. */
        if (!z_zones_are_implemented()) {
                return (BE_SUCCESS);
        }

        /* Get list of supported brands */
        if ((brands = be_get_supported_brandlist()) == NULL) {
                be_print_err(gettext("be_copy_zones: "
                    "no supported brands\n"));
                return (BE_SUCCESS);
        }

        /* Get handle to origin BE's root dataset */
        if ((obe_zhp = zfs_open(g_zfs, obe_root_ds, ZFS_TYPE_FILESYSTEM))
            == NULL) {
                be_print_err(gettext("be_copy_zones: failed to open "
                    "the origin BE root dataset (%s) for zones processing: "
                    "%s\n"), obe_root_ds, libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /* Get handle to newly cloned BE's root dataset */
        if ((nbe_zhp = zfs_open(g_zfs, nbe_root_ds, ZFS_TYPE_FILESYSTEM))
            == NULL) {
                be_print_err(gettext("be_copy_zones: failed to open "
                    "the new BE root dataset (%s): %s\n"), nbe_root_ds,
                    libzfs_error_description(g_zfs));
                ZFS_CLOSE(obe_zhp);
                return (zfs_err_to_be_err(g_zfs));
        }

        /* Get the uuid of the newly cloned parent BE. */
        if (be_get_uuid(zfs_get_name(nbe_zhp), &uu) != BE_SUCCESS) {
                be_print_err(gettext("be_copy_zones: "
                    "failed to get uuid for BE root "
                    "dataset %s\n"), zfs_get_name(nbe_zhp));
                ZFS_CLOSE(nbe_zhp);
                goto done;
        }
        ZFS_CLOSE(nbe_zhp);
        uuid_unparse(uu, uu_string);

        /*
         * If the origin BE is not mounted, we must mount it here to
         * gather data about the non-global zones in it.
         */
        if (!zfs_is_mounted(obe_zhp, &temp_mntpt)) {
                if ((ret = _be_mount(obe_name, &temp_mntpt,
                    BE_MOUNT_FLAG_NULL)) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy_zones: failed to "
                            "mount the BE (%s) for zones procesing.\n"),
                            obe_name);
                        goto done;
                }
                mounted_here = B_TRUE;
        }

        z_set_zone_root(temp_mntpt);

        /* Get list of supported zones. */
        if ((zlist = z_get_nonglobal_zone_list_by_brand(brands)) == NULL) {
                ret = BE_SUCCESS;
                goto done;
        }

        for (i = 0; (zonename = z_zlist_get_zonename(zlist, i)) != NULL; i++) {

                be_fs_list_data_t       fld = { 0 };
                char                    zonepath_ds[MAXPATHLEN];
                char                    *ds = NULL;

                /* Get zonepath of zone */
                zonepath = z_zlist_get_zonepath(zlist, i);

                /* Skip zones that aren't at least installed */
                if (z_zlist_get_current_state(zlist, i) < ZONE_STATE_INSTALLED)
                        continue;

                /*
                 * Get the dataset of this zonepath.  If its not
                 * a dataset, skip it.
                 */
                if ((ds = be_get_ds_from_dir(zonepath)) == NULL)
                        continue;

                (void) strlcpy(zonepath_ds, ds, sizeof (zonepath_ds));
                free(ds);
                ds = NULL;

                /* Get zoneroot directory */
                be_make_zoneroot(zonepath, zoneroot, sizeof (zoneroot));

                /* If zonepath dataset not supported, skip it. */
                if (!be_zone_supported(zonepath_ds)) {
                        continue;
                }

                if ((ret = be_find_active_zone_root(obe_zhp, zonepath_ds,
                    zoneroot_ds, sizeof (zoneroot_ds))) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy_zones: "
                            "failed to find active zone root for zone %s "
                            "in BE %s\n"), zonename, obe_name);
                        goto done;
                }

                if ((ret = be_make_container_ds(zonepath_ds, zone_container_ds,
                    sizeof (zone_container_ds))) != BE_SUCCESS) {
                        be_print_err(gettext("%s: failed to get BE container "
                            "dataset for %s\n"), __func__, zonepath_ds);
                        goto done;
                }

                if ((z_zhp = zfs_open(g_zfs, zoneroot_ds,
                    ZFS_TYPE_FILESYSTEM)) == NULL) {
                        be_print_err(gettext("be_copy_zones: "
                            "failed to open zone root dataset (%s): %s\n"),
                            zoneroot_ds, libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        goto done;
                }

                zone_be_name =
                    be_get_zone_be_name(zoneroot_ds, zone_container_ds);

                if ((new_zone_be_name = be_auto_zone_be_name(zone_container_ds,
                    zone_be_name)) == NULL) {
                        be_print_err(gettext("be_copy_zones: failed "
                            "to generate auto name for zone BE.\n"));
                        ret = BE_ERR_AUTONAME;
                        goto done;
                }

                if ((snap_name = be_auto_snap_name()) == NULL) {
                        be_print_err(gettext("be_copy_zones: failed to "
                            "generate snapshot name for zone BE.\n"));
                        ret = BE_ERR_AUTONAME;
                        goto done;
                }

                (void) snprintf(ss, sizeof (ss), "%s@%s", zoneroot_ds,
                    snap_name);

                if (zfs_snapshot(g_zfs, ss, B_TRUE, NULL) != 0) {
                        be_print_err(gettext("be_copy_zones: "
                            "failed to snapshot zone BE (%s): %s\n"),
                            ss, libzfs_error_description(g_zfs));
                        if (libzfs_errno(g_zfs) == EZFS_EXISTS)
                                ret = BE_ERR_ZONE_SS_EXISTS;
                        else
                                ret = zfs_err_to_be_err(g_zfs);

                        goto done;
                }

                (void) snprintf(new_zoneroot_ds, sizeof (new_zoneroot_ds),
                    "%s/%s", zone_container_ds, new_zone_be_name);

                bt.obe_name = zone_be_name;
                bt.obe_root_ds = zoneroot_ds;
                bt.obe_snap_name = snap_name;
                bt.obe_altroot = temp_mntpt;
                bt.nbe_name = new_zone_be_name;
                bt.nbe_root_ds = new_zoneroot_ds;

                if (nvlist_alloc(&bt.nbe_zfs_props, NV_UNIQUE_NAME, 0) != 0) {
                        be_print_err(gettext("be_copy_zones: "
                            "internal error: out of memory\n"));
                        ret = BE_ERR_NOMEM;
                        goto done;
                }

                /*
                 * The call to be_clone_fs_callback always closes the
                 * zfs_handle so there's no need to close z_zhp.
                 */
                if ((iret = be_clone_fs_callback(z_zhp, &bt)) != 0) {
                        z_zhp = NULL;
                        if (iret != BE_ERR_BE_EXISTS) {
                                be_print_err(gettext("be_copy_zones: "
                                    "failed to create zone BE clone for new "
                                    "zone BE %s\n"), new_zone_be_name);
                                ret = iret;
                                nvlist_free(bt.nbe_zfs_props);
                                goto done;
                        }
                        /*
                         * We failed to create the new zone BE because a zone
                         * BE with the auto-name we generated above has since
                         * come into existence. Regenerate a new auto-name
                         * and retry.
                         */
                        for (num_retries = 1;
                            num_retries < BE_AUTO_NAME_MAX_TRY;
                            num_retries++) {

                                /* Sleep 1 before retrying */
                                (void) sleep(1);

                                /* Generate new auto zone BE name */
                                free(new_zone_be_name);
                                if ((new_zone_be_name = be_auto_zone_be_name(
                                    zone_container_ds,
                                    zone_be_name)) == NULL) {
                                        be_print_err(gettext("be_copy_zones: "
                                            "failed to generate auto name "
                                            "for zone BE.\n"));
                                        ret = BE_ERR_AUTONAME;
                                        nvlist_free(bt.nbe_zfs_props);
                                        goto done;
                                }

                                (void) snprintf(new_zoneroot_ds,
                                    sizeof (new_zoneroot_ds),
                                    "%s/%s", zone_container_ds,
                                    new_zone_be_name);
                                bt.nbe_name = new_zone_be_name;
                                bt.nbe_root_ds = new_zoneroot_ds;

                                /*
                                 * Get handle to original zone BE's root
                                 * dataset.
                                 */
                                if ((z_zhp = zfs_open(g_zfs, zoneroot_ds,
                                    ZFS_TYPE_FILESYSTEM)) == NULL) {
                                        be_print_err(gettext("be_copy_zones: "
                                            "failed to open zone root "
                                            "dataset (%s): %s\n"),
                                            zoneroot_ds,
                                            libzfs_error_description(g_zfs));
                                        ret = zfs_err_to_be_err(g_zfs);
                                        nvlist_free(bt.nbe_zfs_props);
                                        goto done;
                                }

                                /*
                                 * Try to clone the zone BE again. This
                                 * call will end up closing the zfs
                                 * handle passed in whether it
                                 * succeeds or fails.
                                 */
                                iret = be_clone_fs_callback(z_zhp, &bt);
                                z_zhp = NULL;
                                if (iret == 0) {
                                        break;
                                } else if (iret != BE_ERR_BE_EXISTS) {
                                        be_print_err(gettext("be_copy_zones: "
                                            "failed to create zone BE clone "
                                            "for new zone BE %s\n"),
                                            new_zone_be_name);
                                        ret = iret;
                                        nvlist_free(bt.nbe_zfs_props);
                                        goto done;
                                }
                        }
                        /*
                         * If we've exhausted the maximum number of
                         * tries, free the auto zone BE name and return
                         * error.
                         */
                        if (num_retries == BE_AUTO_NAME_MAX_TRY) {
                                be_print_err(gettext("be_copy_zones: failed "
                                    "to create a unique auto zone BE name\n"));
                                free(bt.nbe_name);
                                bt.nbe_name = NULL;
                                ret = BE_ERR_AUTONAME;
                                nvlist_free(bt.nbe_zfs_props);
                                goto done;
                        }
                }

                nvlist_free(bt.nbe_zfs_props);

                z_zhp = NULL;

                if ((z_zhp = zfs_open(g_zfs, new_zoneroot_ds,
                    ZFS_TYPE_FILESYSTEM)) == NULL) {
                        be_print_err(gettext("be_copy_zones: "
                            "failed to open the new zone BE root dataset "
                            "(%s): %s\n"), new_zoneroot_ds,
                            libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        goto done;
                }

                if (zfs_prop_set(z_zhp, BE_ZONE_PARENTBE_PROPERTY,
                    uu_string) != 0) {
                        be_print_err(gettext("be_copy_zones: "
                            "failed to set parentbe property\n"));
                        ZFS_CLOSE(z_zhp);
                        ret = zfs_err_to_be_err(g_zfs);
                        goto done;
                }

                if (zfs_prop_set(z_zhp, BE_ZONE_ACTIVE_PROPERTY, "on") != 0) {
                        be_print_err(gettext("be_copy_zones: "
                            "failed to set active property\n"));
                        ZFS_CLOSE(z_zhp);
                        ret = zfs_err_to_be_err(g_zfs);
                        goto done;
                }

                /*
                 * Generate a list of file systems from the original
                 * zone BE that are legacy mounted.  We use this list
                 * to determine which entries in the vfstab we need to
                 * update for the new zone BE we've just created.
                 */
                if ((ret = be_get_legacy_fs(obe_name, obe_root_ds,
                    zoneroot_ds, zoneroot, &fld)) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy_zones: "
                            "failed to get legacy mounted file system "
                            "list for zone %s\n"), zonename);
                        ZFS_CLOSE(z_zhp);
                        goto done;
                }

                /*
                 * Update new zone BE's vfstab.
                 */
                if ((ret = be_update_zone_vfstab(z_zhp, bt.nbe_name,
                    zonepath_ds, zonepath_ds, &fld)) != BE_SUCCESS) {
                        be_print_err(gettext("be_copy_zones: "
                            "failed to update new BE's vfstab (%s)\n"),
                            bt.nbe_name);
                        ZFS_CLOSE(z_zhp);
                        be_free_fs_list(&fld);
                        goto done;
                }

                be_free_fs_list(&fld);
                ZFS_CLOSE(z_zhp);
        }

done:
        free(snap_name);
        if (brands != NULL)
                z_free_brand_list(brands);
        if (zlist != NULL)
                z_free_zone_list(zlist);

        if (mounted_here)
                (void) _be_unmount(obe_name, 0);

        ZFS_CLOSE(obe_zhp);
        return (ret);
}

/*
 * Function:    be_clone_fs_callback
 * Description: Callback function used to iterate through a BE's filesystems
 *              to clone them for the new BE.
 * Parameters:
 *              zhp - zfs_handle_t pointer for the filesystem being processed.
 *              data - be_transaction_data_t pointer providing information
 *                      about original BE and new BE.
 * Return:
 *              0 - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
static int
be_clone_fs_callback(zfs_handle_t *zhp, void *data)
{
        be_transaction_data_t   *bt = data;
        zfs_handle_t    *zhp_ss = NULL;
        char            prop_buf[MAXPATHLEN];
        char            zhp_name[ZFS_MAX_DATASET_NAME_LEN];
        char            clone_ds[MAXPATHLEN];
        char            ss[MAXPATHLEN];
        int             ret = 0;

        if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, prop_buf,
            ZFS_MAXPROPLEN, NULL, NULL, 0, B_FALSE) != 0) {
                be_print_err(gettext("be_clone_fs_callback: "
                    "failed to get dataset mountpoint (%s): %s\n"),
                    zfs_get_name(zhp), libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                ZFS_CLOSE(zhp);
                return (ret);
        }

        if (zfs_prop_get_int(zhp, ZFS_PROP_ZONED) != 0 &&
            strcmp(prop_buf, "legacy") != 0) {
                /*
                 * Since zfs can't currently handle setting the
                 * mountpoint for a zoned dataset we'll have to skip
                 * this dataset. This is because the mountpoint is not
                 * set to "legacy".
                 */
                goto zoned;
        }
        /*
         * Get a copy of the dataset name from the zfs handle
         */
        (void) strlcpy(zhp_name, zfs_get_name(zhp), sizeof (zhp_name));

        /*
         * Get the clone dataset name and prepare the zfs properties for it.
         */
        if ((ret = be_prep_clone_send_fs(zhp, bt, clone_ds,
            sizeof (clone_ds))) != BE_SUCCESS) {
                ZFS_CLOSE(zhp);
                return (ret);
        }

        /*
         * Generate the name of the snapshot to use.
         */
        (void) snprintf(ss, sizeof (ss), "%s@%s", zhp_name,
            bt->obe_snap_name);

        /*
         * Get handle to snapshot.
         */
        if ((zhp_ss = zfs_open(g_zfs, ss, ZFS_TYPE_SNAPSHOT)) == NULL) {
                be_print_err(gettext("be_clone_fs_callback: "
                    "failed to get handle to snapshot (%s): %s\n"), ss,
                    libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                ZFS_CLOSE(zhp);
                return (ret);
        }

        /*
         * Clone the dataset.
         */
        if (zfs_clone(zhp_ss, clone_ds, bt->nbe_zfs_props) != 0) {
                be_print_err(gettext("be_clone_fs_callback: "
                    "failed to create clone dataset (%s): %s\n"),
                    clone_ds, libzfs_error_description(g_zfs));

                ZFS_CLOSE(zhp_ss);
                ZFS_CLOSE(zhp);

                return (zfs_err_to_be_err(g_zfs));
        }

        ZFS_CLOSE(zhp_ss);

zoned:
        /*
         * Iterate through zhp's children datasets (if any)
         * and clone them accordingly.
         */
        if ((ret = zfs_iter_filesystems(zhp, be_clone_fs_callback, bt)) != 0) {
                /*
                 * Error occurred while processing a child dataset.
                 * Destroy this dataset and return error.
                 */
                zfs_handle_t    *d_zhp = NULL;

                ZFS_CLOSE(zhp);

                if ((d_zhp = zfs_open(g_zfs, clone_ds, ZFS_TYPE_FILESYSTEM))
                    == NULL) {
                        return (ret);
                }

                (void) zfs_destroy(d_zhp, B_FALSE);
                ZFS_CLOSE(d_zhp);
                return (ret);
        }

        ZFS_CLOSE(zhp);
        return (0);
}

/*
 * Function:    be_send_fs_callback
 * Description: Callback function used to iterate through a BE's filesystems
 *              to copy them for the new BE.
 * Parameters:
 *              zhp - zfs_handle_t pointer for the filesystem being processed.
 *              data - be_transaction_data_t pointer providing information
 *                      about original BE and new BE.
 * Return:
 *              0 - Success
 *              be_errnot_t - Failure
 * Scope:
 *              Private
 */
static int
be_send_fs_callback(zfs_handle_t *zhp, void *data)
{
        be_transaction_data_t   *bt = data;
        recvflags_t     flags = { 0 };
        char            zhp_name[ZFS_MAX_DATASET_NAME_LEN];
        char            clone_ds[MAXPATHLEN];
        sendflags_t     send_flags = { 0 };
        int             pid, status, retval;
        int             srpipe[2];
        int             ret = 0;

        /*
         * Get a copy of the dataset name from the zfs handle
         */
        (void) strlcpy(zhp_name, zfs_get_name(zhp), sizeof (zhp_name));

        /*
         * Get the clone dataset name and prepare the zfs properties for it.
         */
        if ((ret = be_prep_clone_send_fs(zhp, bt, clone_ds,
            sizeof (clone_ds))) != BE_SUCCESS) {
                ZFS_CLOSE(zhp);
                return (ret);
        }

        /*
         * Create the new dataset.
         */
        if (zfs_create(g_zfs, clone_ds, ZFS_TYPE_FILESYSTEM, bt->nbe_zfs_props)
            != 0) {
                be_print_err(gettext("be_send_fs_callback: "
                    "failed to create new dataset '%s': %s\n"),
                    clone_ds, libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                ZFS_CLOSE(zhp);
                return (ret);
        }

        /*
         * Destination file system is already created
         * hence we need to set the force flag on
         */
        flags.force = B_TRUE;

        /*
         * Initiate the pipe to be used for the send and recv
         */
        if (pipe(srpipe) != 0) {
                int err = errno;
                be_print_err(gettext("be_send_fs_callback: failed to "
                    "open pipe\n"));
                ZFS_CLOSE(zhp);
                return (errno_to_be_err(err));
        }

        /*
         * Fork off a child to send the dataset
         */
        if ((pid = fork()) == -1) {
                int err = errno;
                be_print_err(gettext("be_send_fs_callback: failed to fork\n"));
                (void) close(srpipe[0]);
                (void) close(srpipe[1]);
                ZFS_CLOSE(zhp);
                return (errno_to_be_err(err));
        } else if (pid == 0) { /* child process */
                (void) close(srpipe[0]);

                /* Send dataset */
                if (zfs_send(zhp, NULL, bt->obe_snap_name, &send_flags,
                    srpipe[1], NULL, NULL, NULL) != 0) {
                        _exit(1);
                }
                ZFS_CLOSE(zhp);

                _exit(0);
        }

        (void) close(srpipe[1]);

        /* Receive dataset */
        if (zfs_receive(g_zfs, clone_ds, NULL, &flags, srpipe[0], NULL) != 0) {
                be_print_err(gettext("be_send_fs_callback: failed to "
                    "recv dataset (%s)\n"), clone_ds);
        }
        (void) close(srpipe[0]);

        /* wait for child to exit */
        do {
                retval = waitpid(pid, &status, 0);
                if (retval == -1) {
                        status = 0;
                }
        } while (retval != pid);

        if (WEXITSTATUS(status) != 0) {
                be_print_err(gettext("be_send_fs_callback: failed to "
                    "send dataset (%s)\n"), zhp_name);
                ZFS_CLOSE(zhp);
                return (BE_ERR_ZFS);
        }


        /*
         * Iterate through zhp's children datasets (if any)
         * and send them accordingly.
         */
        if ((ret = zfs_iter_filesystems(zhp, be_send_fs_callback, bt)) != 0) {
                /*
                 * Error occurred while processing a child dataset.
                 * Destroy this dataset and return error.
                 */
                zfs_handle_t    *d_zhp = NULL;

                ZFS_CLOSE(zhp);

                if ((d_zhp = zfs_open(g_zfs, clone_ds, ZFS_TYPE_FILESYSTEM))
                    == NULL) {
                        return (ret);
                }

                (void) zfs_destroy(d_zhp, B_FALSE);
                ZFS_CLOSE(d_zhp);
                return (ret);
        }

        ZFS_CLOSE(zhp);
        return (0);
}

/*
 * Function:    be_destroy_callback
 * Description: Callback function used to destroy a BEs children datasets
 *              and snapshots.
 * Parameters:
 *              zhp - zfs_handle_t pointer to the filesystem being processed.
 *              data - Not used.
 * Returns:
 *              0 - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
static int
be_destroy_callback(zfs_handle_t *zhp, void *data)
{
        be_destroy_data_t       *dd = data;
        int ret = 0;

        /*
         * Iterate down this file system's hierarchical children
         * and destroy them first.
         */
        if ((ret = zfs_iter_filesystems(zhp, be_destroy_callback, dd)) != 0) {
                ZFS_CLOSE(zhp);
                return (ret);
        }

        if (dd->destroy_snaps) {
                /*
                 * Iterate through this file system's snapshots and
                 * destroy them before destroying the file system itself.
                 */
                if ((ret = zfs_iter_snapshots(zhp, B_FALSE, be_destroy_callback,
                    dd))
                    != 0) {
                        ZFS_CLOSE(zhp);
                        return (ret);
                }
        }

        /* Attempt to unmount the dataset before destroying it */
        if (dd->force_unmount) {
                if ((ret = zfs_unmount(zhp, NULL, MS_FORCE)) != 0) {
                        be_print_err(gettext("be_destroy_callback: "
                            "failed to unmount %s: %s\n"), zfs_get_name(zhp),
                            libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        ZFS_CLOSE(zhp);
                        return (ret);
                }
        }

        if (zfs_destroy(zhp, B_FALSE) != 0) {
                be_print_err(gettext("be_destroy_callback: "
                    "failed to destroy %s: %s\n"), zfs_get_name(zhp),
                    libzfs_error_description(g_zfs));
                ret = zfs_err_to_be_err(g_zfs);
                ZFS_CLOSE(zhp);
                return (ret);
        }

        ZFS_CLOSE(zhp);
        return (0);
}

/*
 * Function:    be_demote_callback
 * Description: This callback function is used to iterate through the file
 *              systems of a BE, looking for the right clone to promote such
 *              that this file system is left without any dependent clones.
 *              If the file system has no dependent clones, it doesn't need
 *              to get demoted, and the function will return success.
 *
 *              The demotion will be done in two passes.  The first pass
 *              will attempt to find the youngest snapshot that has a clone
 *              that is part of some other BE.  The second pass will attempt
 *              to find the youngest snapshot that has a clone that is not
 *              part of a BE.  Doing this helps ensure the aggregated set of
 *              file systems that compose a BE stay coordinated wrt BE
 *              snapshots and BE dependents.  It also prevents a random user
 *              generated clone of a BE dataset to become the parent of other
 *              BE datasets after demoting this dataset.
 *
 * Parameters:
 *              zhp - zfs_handle_t pointer to the current file system being
 *                      processed.
 *              data - not used.
 * Return:
 *              0 - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
static int
/* LINTED */
be_demote_callback(zfs_handle_t *zhp, void *data)
{
        be_demote_data_t        dd = { 0 };
        int                     i, ret = 0;

        /*
         * Initialize be_demote_data for the first pass - this will find a
         * clone in another BE, if one exists.
         */
        dd.find_in_BE = B_TRUE;

        for (i = 0; i < 2; i++) {

                if (zfs_iter_snapshots(zhp, B_FALSE,
                    be_demote_find_clone_callback, &dd) != 0) {
                        be_print_err(gettext("be_demote_callback: "
                            "failed to iterate snapshots for %s: %s\n"),
                            zfs_get_name(zhp), libzfs_error_description(g_zfs));
                        ret = zfs_err_to_be_err(g_zfs);
                        ZFS_CLOSE(zhp);
                        return (ret);
                }
                if (dd.clone_zhp != NULL) {
                        /* Found the clone to promote.  Promote it. */
                        if (zfs_promote(dd.clone_zhp) != 0) {
                                be_print_err(gettext("be_demote_callback: "
                                    "failed to promote %s: %s\n"),
                                    zfs_get_name(dd.clone_zhp),
                                    libzfs_error_description(g_zfs));
                                ret = zfs_err_to_be_err(g_zfs);
                                ZFS_CLOSE(dd.clone_zhp);
                                ZFS_CLOSE(zhp);
                                return (ret);
                        }

                        ZFS_CLOSE(dd.clone_zhp);
                }

                /*
                 * Reinitialize be_demote_data for the second pass.
                 * This will find a user created clone outside of any BE
                 * namespace, if one exists.
                 */
                dd.clone_zhp = NULL;
                dd.origin_creation = 0;
                dd.snapshot = NULL;
                dd.find_in_BE = B_FALSE;
        }

        /* Iterate down this file system's children and demote them */
        if ((ret = zfs_iter_filesystems(zhp, be_demote_callback, NULL)) != 0) {
                ZFS_CLOSE(zhp);
                return (ret);
        }

        ZFS_CLOSE(zhp);
        return (0);
}

/*
 * Function:    be_demote_find_clone_callback
 * Description: This callback function is used to iterate through the
 *              snapshots of a dataset, looking for the youngest snapshot
 *              that has a clone.  If found, it returns a reference to the
 *              clone back to the caller in the callback data.
 * Parameters:
 *              zhp - zfs_handle_t pointer to current snapshot being looked at
 *              data - be_demote_data_t pointer used to store the clone that
 *                      is found.
 * Returns:
 *              0 - Successfully iterated through all snapshots.
 *              1 - Failed to iterate through all snapshots.
 * Scope:
 *              Private
 */
static int
be_demote_find_clone_callback(zfs_handle_t *zhp, void *data)
{
        be_demote_data_t        *dd = data;
        time_t                  snap_creation;
        int                     zret = 0;

        /* If snapshot has no clones, no need to look at it */
        if (zfs_prop_get_int(zhp, ZFS_PROP_NUMCLONES) == 0) {
                ZFS_CLOSE(zhp);
                return (0);
        }

        dd->snapshot = zfs_get_name(zhp);

        /* Get the creation time of this snapshot */
        snap_creation = (time_t)zfs_prop_get_int(zhp, ZFS_PROP_CREATION);

        /*
         * If this snapshot's creation time is greater than (or younger than)
         * the current youngest snapshot found, iterate this snapshot to
         * check if it has a clone that we're looking for.
         */
        if (snap_creation >= dd->origin_creation) {
                /*
                 * Iterate the dependents of this snapshot to find a
                 * a clone that's a direct dependent.
                 */
                if ((zret = zfs_iter_dependents(zhp, B_FALSE,
                    be_demote_get_one_clone, dd)) == -1) {
                        be_print_err(gettext("be_demote_find_clone_callback: "
                            "failed to iterate dependents of %s\n"),
                            zfs_get_name(zhp));
                        ZFS_CLOSE(zhp);
                        return (1);
                } else if (zret == 1) {
                        /*
                         * Found a clone, update the origin_creation time
                         * in the callback data.
                         */
                        dd->origin_creation = snap_creation;
                }
        }

        ZFS_CLOSE(zhp);
        return (0);
}

/*
 * Function:    be_demote_get_one_clone
 * Description: This callback function is used to iterate through a
 *              snapshot's dependencies to find a filesystem that is a
 *              direct clone of the snapshot being iterated.
 * Parameters:
 *              zhp - zfs_handle_t pointer to current dataset being looked at
 *              data - be_demote_data_t pointer used to store the clone
 *                      that is found, and also provides flag to note
 *                      whether or not the clone filesystem being searched
 *                      for needs to be found in a BE dataset hierarchy.
 * Return:
 *              1 - Success, found clone and its also a BE's root dataset.
 *              0 - Failure, clone not found.
 * Scope:
 *              Private
 */
static int
be_demote_get_one_clone(zfs_handle_t *zhp, void *data)
{
        be_demote_data_t        *dd = data;
        char                    origin[ZFS_MAX_DATASET_NAME_LEN];
        char                    ds_path[ZFS_MAX_DATASET_NAME_LEN];

        if (zfs_get_type(zhp) != ZFS_TYPE_FILESYSTEM) {
                ZFS_CLOSE(zhp);
                return (0);
        }

        (void) strlcpy(ds_path, zfs_get_name(zhp), sizeof (ds_path));

        /*
         * Make sure this is a direct clone of the snapshot
         * we're iterating.
         */
        if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin, sizeof (origin), NULL,
            NULL, 0, B_FALSE) != 0) {
                be_print_err(gettext("be_demote_get_one_clone: "
                    "failed to get origin of %s: %s\n"), ds_path,
                    libzfs_error_description(g_zfs));
                ZFS_CLOSE(zhp);
                return (0);
        }
        if (strcmp(origin, dd->snapshot) != 0) {
                ZFS_CLOSE(zhp);
                return (0);
        }

        if (dd->find_in_BE) {
                if ((zpool_iter(g_zfs, be_check_be_roots_callback, ds_path))
                    > 0) {
                        if (dd->clone_zhp != NULL)
                                ZFS_CLOSE(dd->clone_zhp);
                        dd->clone_zhp = zhp;
                        return (1);
                }

                ZFS_CLOSE(zhp);
                return (0);
        }

        if (dd->clone_zhp != NULL)
                ZFS_CLOSE(dd->clone_zhp);

        dd->clone_zhp = zhp;
        return (1);
}

/*
 * Function:    be_get_snap
 * Description: This function takes a snapshot dataset name and separates
 *              out the parent dataset portion from the snapshot name.
 *              I.e. it finds the '@' in the snapshot dataset name and
 *              replaces it with a '\0'.
 * Parameters:
 *              origin - char pointer to a snapshot dataset name.  Its
 *                      contents will be modified by this function.
 *              *snap - pointer to a char pointer.  Will be set to the
 *                      snapshot name portion upon success.
 * Return:
 *              BE_SUCCESS - Success
 *              1 - Failure
 * Scope:
 *              Private
 */
static int
be_get_snap(char *origin, char **snap)
{
        char    *cp;

        /*
         * Separate out the origin's dataset and snapshot portions by
         * replacing the @ with a '\0'
         */
        cp = strrchr(origin, '@');
        if (cp != NULL) {
                if (cp[1] != '\0') {
                        cp[0] = '\0';
                        *snap = cp+1;
                } else {
                        return (1);
                }
        } else {
                return (1);
        }

        return (BE_SUCCESS);
}

/*
 * Function:    be_create_container_ds
 * Description: This function checks that the zpool passed has the BE
 *              container dataset, and if not, then creates it.
 * Parameters:
 *              zpool - name of pool to create BE container dataset in.
 * Return:
 *              B_TRUE - Successfully created BE container dataset, or it
 *                      already existed.
 *              B_FALSE - Failed to create container dataset.
 * Scope:
 *              Private
 */
static boolean_t
be_create_container_ds(char *zpool)
{
        nvlist_t        *props = NULL;
        char            be_container_ds[MAXPATHLEN];

        /* Generate string for BE container dataset for this pool */
        if (be_make_container_ds(zpool, be_container_ds,
            sizeof (be_container_ds)) != BE_SUCCESS) {
                be_print_err(gettext("%s: failed to get BE container dataset "
                    "for %s\n"), __func__, zpool);
                return (B_FALSE);
        }

        if (!zfs_dataset_exists(g_zfs, be_container_ds, ZFS_TYPE_FILESYSTEM)) {

                if (nvlist_alloc(&props, NV_UNIQUE_NAME, 0) != 0) {
                        be_print_err(gettext("be_create_container_ds: "
                            "nvlist_alloc failed\n"));
                        return (B_FALSE);
                }

                if (nvlist_add_string(props,
                    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
                    ZFS_MOUNTPOINT_LEGACY) != 0) {
                        be_print_err(gettext("be_create_container_ds: "
                            "internal error: out of memory\n"));
                        nvlist_free(props);
                        return (B_FALSE);
                }

                if (nvlist_add_string(props,
                    zfs_prop_to_name(ZFS_PROP_CANMOUNT), "off") != 0) {
                        be_print_err(gettext("be_create_container_ds: "
                            "internal error: out of memory\n"));
                        nvlist_free(props);
                        return (B_FALSE);
                }

                if (zfs_create(g_zfs, be_container_ds, ZFS_TYPE_FILESYSTEM,
                    props) != 0) {
                        be_print_err(gettext("be_create_container_ds: "
                            "failed to create container dataset (%s): %s\n"),
                            be_container_ds, libzfs_error_description(g_zfs));
                        nvlist_free(props);
                        return (B_FALSE);
                }

                nvlist_free(props);
        }

        return (B_TRUE);
}

/*
 * Function:    be_prep_clone_send_fs
 * Description: This function takes a zfs handle to a dataset from the
 *              original BE, and generates the name of the clone dataset
 *              to create for the new BE.  It also prepares the zfs
 *              properties to be used for the new BE.
 * Parameters:
 *              zhp - pointer to zfs_handle_t of the file system being
 *                      cloned/copied.
 *              bt - be_transaction_data pointer providing information
 *                      about the original BE and new BE.
 *              clone_ds - buffer to store the name of the dataset
 *                      for the new BE.
 *              clone_ds_len - length of clone_ds buffer
 * Return:
 *              BE_SUCCESS - Success
 *              be_errno_t - Failure
 * Scope:
 *              Private
 */
static int
be_prep_clone_send_fs(zfs_handle_t *zhp, be_transaction_data_t *bt,
    char *clone_ds, int clone_ds_len)
{
        zprop_source_t  sourcetype;
        char            source[ZFS_MAX_DATASET_NAME_LEN];
        char            zhp_name[ZFS_MAX_DATASET_NAME_LEN];
        char            mountpoint[MAXPATHLEN];
        char            *child_fs = NULL;
        char            *zhp_mountpoint = NULL;
        int             err = 0;

        /*
         * Get a copy of the dataset name zfs_name from zhp
         */
        (void) strlcpy(zhp_name, zfs_get_name(zhp), sizeof (zhp_name));

        /*
         * Get file system name relative to the root.
         */
        if (strncmp(zhp_name, bt->obe_root_ds, strlen(bt->obe_root_ds))
            == 0) {
                child_fs = zhp_name + strlen(bt->obe_root_ds);

                /*
                 * if child_fs is NULL, this means we're processing the
                 * root dataset itself; set child_fs to the empty string.
                 */
                if (child_fs == NULL)
                        child_fs = "";
        } else {
                return (BE_ERR_INVAL);
        }

        /*
         * Generate the name of the clone file system.
         */
        (void) snprintf(clone_ds, clone_ds_len, "%s%s", bt->nbe_root_ds,
            child_fs);

        /* Get the mountpoint and source properties of the existing dataset */
        if (zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint,
            sizeof (mountpoint), &sourcetype, source, sizeof (source),
            B_FALSE) != 0) {
                be_print_err(gettext("be_prep_clone_send_fs: "
                    "failed to get mountpoint for (%s): %s\n"),
                    zhp_name, libzfs_error_description(g_zfs));
                return (zfs_err_to_be_err(g_zfs));
        }

        /*
         * Workaround for 6668667 where a mountpoint property of "/" comes
         * back as "".
         */
        if (strcmp(mountpoint, "") == 0) {
                (void) snprintf(mountpoint, sizeof (mountpoint), "/");
        }

        /*
         * Figure out what to set as the mountpoint for the new dataset.
         * If the source of the mountpoint property is local, use the
         * mountpoint value itself.  Otherwise, remove it from the
         * zfs properties list so that it gets inherited.
         */
        if (sourcetype & ZPROP_SRC_LOCAL) {
                /*
                 * If the BE that this file system is a part of is
                 * currently mounted, strip off the BE altroot portion
                 * from the mountpoint.
                 */
                zhp_mountpoint = mountpoint;

                if (strcmp(mountpoint, ZFS_MOUNTPOINT_LEGACY) != 0 &&
                    bt->obe_altroot != NULL && strcmp(bt->obe_altroot,
                    "/") != 0 && zfs_is_mounted(zhp, NULL)) {

                        int altroot_len = strlen(bt->obe_altroot);

                        if (strncmp(bt->obe_altroot, mountpoint, altroot_len)
                            == 0) {
                                if (mountpoint[altroot_len] == '/')
                                        zhp_mountpoint = mountpoint +
                                            altroot_len;
                                else if (mountpoint[altroot_len] == '\0')
                                        (void) snprintf(mountpoint,
                                            sizeof (mountpoint), "/");
                        }
                }

                if (nvlist_add_string(bt->nbe_zfs_props,
                    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT),
                    zhp_mountpoint) != 0) {
                        be_print_err(gettext("be_prep_clone_send_fs: "
                            "internal error: out of memory\n"));
                        return (BE_ERR_NOMEM);
                }
        } else {
                err = nvlist_remove_all(bt->nbe_zfs_props,
                    zfs_prop_to_name(ZFS_PROP_MOUNTPOINT));
                if (err != 0 && err != ENOENT) {
                        be_print_err(gettext("be_prep_clone_send_fs: "
                            "failed to remove mountpoint from "
                            "nvlist\n"));
                        return (BE_ERR_INVAL);
                }
        }

        /*
         * Set the 'canmount' property
         */
        if (nvlist_add_string(bt->nbe_zfs_props,
            zfs_prop_to_name(ZFS_PROP_CANMOUNT), "noauto") != 0) {
                be_print_err(gettext("be_prep_clone_send_fs: "
                    "internal error: out of memory\n"));
                return (BE_ERR_NOMEM);
        }

        return (BE_SUCCESS);
}

/*
 * Function:    be_get_zone_be_name
 * Description: This function takes the zones root dataset, the container
 *              dataset and returns the zones BE name based on the zone
 *              root dataset.
 * Parameters:
 *              root_ds - the zones root dataset.
 *              container_ds - the container dataset for the zone.
 * Returns:
 *              char * - the BE name of this zone based on the root dataset.
 */
static char *
be_get_zone_be_name(char *root_ds, char *container_ds)
{
        return (root_ds + (strlen(container_ds) + 1));
}

/*
 * Function:    be_zone_root_exists_callback
 * Description: This callback function is used to determine if a
 *              zone root container dataset has any children.  It always
 *              returns 1, signifying a hierarchical child of the zone
 *              root container dataset has been traversed and therefore
 *              it has children.
 * Parameters:
 *              zhp - zfs_handle_t pointer to current dataset being processed.
 *              data - not used.
 * Returns:
 *              1 - dataset exists
 * Scope:
 *              Private
 */
static int
/* LINTED */
be_zone_root_exists_callback(zfs_handle_t *zhp, void *data)
{
        ZFS_CLOSE(zhp);
        return (1);
}