From ebd3b79f20c4bcf6d01943c31528e8f5620cce5d Mon Sep 17 00:00:00 2001
From: Andriy Gapon <avg@FreeBSD.org>
Date: Thu, 13 Oct 2016 06:19:54 +0000
Subject: [PATCH] rc.d/zfsbe: a new script designed for boot environment
 support

Currently zfsbe ensures that subordinate filesystems are mounted at the
right mount points.
The script assumes that the subordinate filesystems of a boot environment
have their canmount property set to noauto, so that they are not
automatically mounted on boot.  Whereas the root filesystem is mounted
by the kernel, there was nothing to mount its subordinates.
rc.d/zfsbe fills that gap.

Discussed with:	allanjude, will
MFC after:	3 weeks
Differential Revision: https://reviews.freebsd.org/D7797
---
 etc/rc.d/zfs   |  2 +-
 etc/rc.d/zfsbe | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100755 etc/rc.d/zfsbe

diff --git a/etc/rc.d/zfs b/etc/rc.d/zfs
index a98487c1393..2d35f9b5464 100755
--- a/etc/rc.d/zfs
+++ b/etc/rc.d/zfs
@@ -4,7 +4,7 @@
 #
 
 # PROVIDE: zfs
-# REQUIRE: mountcritlocal
+# REQUIRE: zfsbe
 # BEFORE: FILESYSTEMS var
 
 . /etc/rc.subr
diff --git a/etc/rc.d/zfsbe b/etc/rc.d/zfsbe
new file mode 100755
index 00000000000..3c852017aa4
--- /dev/null
+++ b/etc/rc.d/zfsbe
@@ -0,0 +1,71 @@
+#!/bin/sh
+#
+# $FreeBSD$
+#
+
+# PROVIDE: zfsbe
+# REQUIRE: mountcritlocal
+
+# Handle boot environment subordinate filesystems
+# that may have canmount property set to noauto.
+# For these filesystems mountpoint relative to /
+# must be the same as their dataset name relative
+# to BE root dataset.
+
+. /etc/rc.subr
+
+name="zfsbe"
+rcvar="zfs_enable"
+start_cmd="be_start"
+stop_cmd="be_stop"
+required_modules="zfs"
+
+mount_subordinate()
+{
+	local _be
+
+	_be=$1
+	zfs list -rH -o mountpoint,name,canmount,mounted -s mountpoint -t filesystem $_be | \
+	while read _mp _name _canmount _mounted ; do
+		# skip filesystems that must not be mounted
+		[ "$_canmount" = "off" ] && continue
+		# skip filesystems that are already mounted
+		[ "$_mounted" = "yes" ] && continue
+		case "$_mp" in
+		"none" | "legacy" | "/" | "/$_be")
+			# do nothing for filesystems with unset or legacy mountpoint
+			# or those that would be mounted over /
+			;;
+		"/$_be/"*)
+			# filesystems with mountpoint relative to BE
+			mount -t zfs $_name ${_mp#/$_be}
+			;;
+		*)
+			# filesystems with mountpoint elsewhere
+			zfs mount $_name
+			;;
+		esac
+	done
+}
+
+be_start()
+{
+	if [ `$SYSCTL_N security.jail.jailed` -eq 1 ]; then
+		:
+	else
+		mount -p | while read _dev _mp _type _rest; do
+			[ $_mp  = "/" ] || continue
+			if [ $_type = "zfs" ] ; then
+				mount_subordinate $_dev
+			fi
+			break
+		done
+	fi
+}
+
+be_stop()
+{
+}
+
+load_rc_config $name
+run_rc_command "$1"