Index: head/tools/build/beinstall.sh
===================================================================
--- head/tools/build/beinstall.sh	(revision 336855)
+++ head/tools/build/beinstall.sh	(revision 336856)
@@ -1,161 +1,247 @@
 #!/bin/sh
 #
 # Copyright (c) 2016 Will Andrews
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer 
 #    in this position and unchanged.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 # IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 # OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 # IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #
 # $FreeBSD$
 #
 ##
 # Install a boot environment using the current FreeBSD source tree.
 # Requires a fully built world & kernel.
 #
 # Non-base tools required: beadm, pkg
 #
 # In a sandbox for the new boot environment, this script also runs etcupdate
 # and pkg upgrade automatically in the sandbox.  Upon successful completion,
 # the system will be ready to boot into the new boot environment.  Upon
 # failure, the target boot environment will be destroyed.  In all cases, the
 # running system is left untouched.
 #
 ## Usage:
 # beinstall [optional world/kernel flags e.g. KERNCONF]
 #
 ## User modifiable variables - set these in the environment if desired.
 # If not empty, 'pkg upgrade' will be skipped.
 NO_PKG_UPGRADE="${NO_PKG_UPGRADE:-""}"
 # Config updater - 'etcupdate' and 'mergemaster' are supported.  Set to an
 # empty string to skip.
 CONFIG_UPDATER="${CONFIG_UPDATER:-"etcupdate"}"
 # Flags for etcupdate if used.
 ETCUPDATE_FLAGS="${ETCUPDATE_FLAGS:-"-F"}"
 # Flags for mergemaster if used.
 MERGEMASTER_FLAGS="${MERGEMASTER_FLAGS:-"-iFU"}"
 
 
 ########################################################################
 ## Constants
 ETCUPDATE_CMD="etcupdate"
 MERGEMASTER_CMD="mergemaster"
 
 ## Functions
 cleanup() {
 	[ -z "${cleanup_commands}" ] && return
 	echo "Cleaning up ..."
 	for command in ${cleanup_commands}; do
 		${command}
 	done
 }
 
 errx() {
 	cleanup
 	echo "error: $@"
 	exit 1
 }
 
 rmdir_be() {
 	chflags -R noschg ${BE_MNTPT}
 	rm -rf ${BE_MNTPT}
 }
 
+unmount_be() {
+	mount | grep " on ${BE_MNTPT}" | awk '{print $3}' | sort -r | xargs -t umount -f
+}
+
 cleanup_be() {
+	# Before destroying, unmount any child filesystems that may have
+	# been mounted under the boot environment.  Sort them in reverse
+	# order so children are unmounted first.
+	unmount_be
+	# Finally, clean up any directories that were created by the
+	# operation, via cleanup_be_dirs().
+	if [ -n "${created_be_dirs}" ]; then
+		chroot ${BE_MNTPT} /bin/rm -rf ${created_be_dirs}
+	fi
 	beadm destroy -F ${BENAME}
 }
 
+create_be_dirs() {
+	echo "${BE_MNTPT}: Inspecting dirs $*"
+	for dir in $*; do
+		curdir="$dir"
+		topdir="$dir"
+		while :; do
+			[ -e "${BE_MNTPT}${curdir}" ] && break
+			topdir=$curdir
+			curdir=$(dirname ${curdir})
+		done
+		[ "$curdir" = "$dir" ] && continue
+
+		# Add the top-most nonexistent directory to the list, then
+		# mkdir -p the innermost directory specified by the argument.
+		# This way the least number of directories are rm'd directly.
+		created_be_dirs="${topdir} ${created_be_dirs}"
+		echo "${BE_MNTPT}: Created ${dir}"
+		mkdir -p ${BE_MNTPT}${dir} || return $?
+	done
+	return 0
+}
+
+update_mergemaster_pre() {
+	mergemaster -p -m ${srcdir} -D ${BE_MNTPT} -t ${BE_MM_ROOT} ${MERGEMASTER_FLAGS}
+}
+
 update_mergemaster() {
-	mergemaster -m $(pwd) -D ${BE_MNTPT} -t ${BE_MM_ROOT} ${MERGEMASTER_FLAGS}
+	chroot ${BE_MNTPT} \
+		mergemaster -m ${srcdir} -t ${BE_MM_ROOT} ${MERGEMASTER_FLAGS}
 }
 
+update_etcupdate_pre() {
+	etcupdate -p -s ${srcdir} -D ${BE_MNTPT} ${ETCUPDATE_FLAGS} || return $?
+	etcupdate resolve -D ${BE_MNTPT} || return $?
+}
+
 update_etcupdate() {
-	etcupdate -s $(pwd) -D ${BE_MNTPT} ${ETCUPDATE_FLAGS} || return $?
-	etcupdate resolve -D ${BE_MNTPT}
+	chroot ${BE_MNTPT} \
+		etcupdate -s ${srcdir} ${ETCUPDATE_FLAGS} || return $?
+	chroot ${BE_MNTPT} etcupdate resolve
 }
 
 
+# Special command-line subcommand that can be used to do a full cleanup
+# after a manual post-mortem has been completed.
+postmortem() {
+	[ -n "${BENAME}" ] || errx "Must specify BENAME"
+	[ -n "${BE_MNTPT}" ] || errx "Must specify BE_MNTPT"
+	echo "Performing post-mortem on BE ${BENAME} at ${BE_MNTPT} ..."
+	unmount_be
+	rmdir_be
+	echo "Post-mortem cleanup complete."
+	echo "To destroy the BE (recommended), run: beadm destroy ${BENAME}"
+	echo "To instead continue with the BE, run: beadm activate ${BENAME}"
+}
+
+if [ -n "$BEINSTALL_CMD" ]; then
+	${BEINSTALL_CMD} $*
+	exit $?
+fi
+
+
 cleanup_commands=""
 trap 'errx "Interrupt caught"' HUP INT TERM
 
 [ "$(whoami)" != "root" ] && errx "Must be run as root"
 
 [ ! -f "Makefile.inc1" ] && errx "Must be in FreeBSD source tree"
+srcdir=$(pwd)
 objdir=$(make -V .OBJDIR 2>/dev/null)
 [ ! -d "${objdir}" ] && errx "Must have built FreeBSD from source tree"
 
 # May be a worktree, in which case .git is a file, not a directory.
 if [ -e .git ] ; then
     commit_time=$(git show --format='%ct' 2>/dev/null | head -1)
     [ $? -ne 0 ] && errx "Can't lookup git commit timestamp"
     commit_ts=$(date -r ${commit_time} '+%Y%m%d.%H%M%S')
 elif [ -d .svn ] ; then
       if [ -e /usr/bin/svnlite ]; then
         svn=/usr/bin/svnlite
       elif [ -e /usr/local/bin/svn ]; then
         svn=/usr/local/bin/svn
       else
         errx "Unable to find subversion"
       fi
       commit_ts="$( "$svn" info --show-item last-changed-date | sed -e 's/\..*//' -e 's/T/./' -e 's/-//g' -e s'/://g' )"
     [ $? -ne 0 ] && errx "Can't lookup Subversion commit timestamp"
 else
     errx "Unable to determine source control type"
 fi
 
 commit_ver=$(${objdir}/bin/freebsd-version/freebsd-version -u 2>/dev/null)
 [ -z "${commit_ver}" ] && errx "Unable to determine FreeBSD version"
 
 BENAME="${commit_ver}-${commit_ts}"
 
 BE_TMP=$(mktemp -d /tmp/beinstall.XXXXXX)
 [ $? -ne 0 -o ! -d ${BE_TMP} ] && errx "Unable to create mountpoint"
 [ -z "$NO_CLEANUP_BE" ] && cleanup_commands="rmdir_be ${cleanup_commands}"
 BE_MNTPT=${BE_TMP}/mnt
 BE_MM_ROOT=${BE_TMP}/mergemaster # mergemaster will create
 mkdir -p ${BE_MNTPT}
 
 beadm create ${BENAME} >/dev/null || errx "Unable to create BE ${BENAME}"
 [ -z "$NO_CLEANUP_BE" ] && cleanup_commands="cleanup_be ${cleanup_commands}"
 
 beadm mount ${BENAME} ${BE_TMP}/mnt || errx "Unable to mount BE ${BENAME}."
 
 echo "Mounted ${BENAME} to ${BE_MNTPT}, performing install/update ..."
 make "$@" DESTDIR=${BE_MNTPT} installkernel || errx "Installkernel failed!"
-make "$@" DESTDIR=${BE_MNTPT} installworld || errx "Installworld failed!"
+if [ -n "${CONFIG_UPDATER}" ]; then
+	"update_${CONFIG_UPDATER}_pre"
+	[ $? -ne 0 ] && errx "${CONFIG_UPDATER} (pre-world) failed!"
+fi
 
+# Mount the source and object tree within the BE in order to account for any
+# changes applied by the pre-installworld updater.  Cleanup any directories
+# created if they didn't exist previously.
+create_be_dirs "${srcdir}" "${objdir}" || errx "Unable to create BE dirs"
+mount -t nullfs "${srcdir}" "${BE_MNTPT}${srcdir}" || errx "Unable to mount src"
+mount -t nullfs "${objdir}" "${BE_MNTPT}${objdir}" || errx "Unable to mount obj"
+
+chroot ${BE_MNTPT} make "$@" -C ${srcdir} installworld || \
+	errx "Installworld failed!"
+
 if [ -n "${CONFIG_UPDATER}" ]; then
 	"update_${CONFIG_UPDATER}"
-	[ $? -ne 0 ] && errx "${CONFIG_UPDATER} failed!"
+	[ $? -ne 0 ] && errx "${CONFIG_UPDATER} (post-world) failed!"
 fi
 
 BE_PKG="chroot ${BE_MNTPT} env ASSUME_ALWAYS_YES=true pkg"
 if [ -z "${NO_PKG_UPGRADE}" ]; then
 	${BE_PKG} update || errx "Unable to update pkg"
 	${BE_PKG} upgrade || errx "Unable to upgrade pkgs"
 fi
 
-beadm unmount ${BENAME} || errx "Unable to unmount BE"
-rmdir_be
+if [ -n "$NO_CLEANUP_BE" ]; then
+	echo "Boot Environment ${BENAME} may be examined in ${BE_MNTPT}."
+	echo "Afterwards, run this to cleanup:"
+	echo "  env BENAME=${BENAME} BE_MNTPT=${BE_MNTPT} BEINSTALL_CMD=postmortem $0"
+	exit 0
+fi
+
+unmount_be || errx "Unable to unmount BE"
+rmdir_be || errx "Unable to cleanup BE"
 beadm activate ${BENAME} || errx "Unable to activate BE"
 echo
 beadm list
 echo
 echo "Boot environment ${BENAME} setup complete; reboot to use it."