Index: lib/libbe/be.c
===================================================================
--- lib/libbe/be.c
+++ lib/libbe/be.c
@@ -104,6 +104,32 @@
 	return (0);
 }
 
+/* Validate a root filesystem by verifying that every child dataset
+ * is has a mountpoint of '/' (minus altroot) or 'none'.
+ */
+static int
+be_validate_rootfs_cb(zfs_handle_t *zfs_hdl, void *data)
+{
+	libbe_handle_t *lbh;
+	char *mountpoint;
+	char zfs_mnt[BE_MAXPATHLEN];
+
+	lbh = (libbe_handle_t *)data;
+
+	if(zfs_prop_get(zfs_hdl, ZFS_PROP_MOUNTPOINT, zfs_mnt, BE_MAXPATHLEN, NULL, 
+			NULL, 0, 1))
+		return (1);
+
+	if (strcmp("none", zfs_mnt) == 0)
+		return (0);
+
+	mountpoint = zfs_mnt + lbh->altroot_len;
+	if (strcmp("/", mountpoint) == 0 || strcmp("", mountpoint) == 0)
+		return (0);
+
+	return (1);
+}
+
 /*
  * Initializes the libbe context to operate in the root boot environment
  * dataset, for example, zroot/ROOT.
@@ -113,11 +139,13 @@
 {
 	char altroot[MAXPATHLEN];
 	libbe_handle_t *lbh;
+	zfs_handle_t *zhdl;
 	char *poolname, *pos;
 	int pnamelen;
 
 	lbh = NULL;
 	poolname = pos = NULL;
+	zhdl = NULL;
 
 	if ((lbh = calloc(1, sizeof(libbe_handle_t))) == NULL)
 		goto err;
@@ -144,19 +172,21 @@
 	} else
 		strlcpy(lbh->root, root, sizeof(lbh->root));
 
-	if ((pos = strchr(lbh->root, '/')) == NULL)
-		goto err;
-
-	pnamelen = pos - lbh->root;
-	poolname = malloc(pnamelen + 1);
-	if (poolname == NULL)
-		goto err;
+	if ((pos = strchr(lbh->root, '/')) == NULL) {
+		if(root == NULL || (lbh->active_phandle = zpool_open(lbh->lzh, lbh->root)) == NULL)
+			goto err;
+	} else {
+		pnamelen = pos - lbh->root;
+		poolname = malloc(pnamelen + 1);
+		if (poolname == NULL)
+			goto err;
 
-	strlcpy(poolname, lbh->root, pnamelen + 1);
-	if ((lbh->active_phandle = zpool_open(lbh->lzh, poolname)) == NULL)
-		goto err;
-	free(poolname);
-	poolname = NULL;
+		strlcpy(poolname, lbh->root, pnamelen + 1);
+		if ((lbh->active_phandle = zpool_open(lbh->lzh, poolname)) == NULL)
+			goto err;
+		free(poolname);
+		poolname = NULL;
+	}
 
 	if (zpool_get_prop(lbh->active_phandle, ZPOOL_PROP_BOOTFS, lbh->bootfs,
 	    sizeof(lbh->bootfs), NULL, true) != 0)
@@ -167,11 +197,20 @@
 	    strcmp(altroot, "-") != 0)
 		lbh->altroot_len = strlen(altroot);
 
+	/* Validate child filesystems, to make sure they are mountpoint '/' or 'none' */
+	zhdl = zfs_open(lbh->lzh, lbh->root, ZFS_TYPE_FILESYSTEM);
+	if(zfs_iter_filesystems(zhdl, be_validate_rootfs_cb, lbh))
+		goto err;
+
+	zfs_close(zhdl);
+
 	return (lbh);
 err:
 	if (lbh != NULL) {
 		if (lbh->active_phandle != NULL)
 			zpool_close(lbh->active_phandle);
+		if (zhdl != NULL)
+			zfs_close(zhdl);
 		if (lbh->lzh != NULL)
 			libzfs_fini(lbh->lzh);
 		free(lbh);