[chroot] WARNING: NEEDS BETTER TESTING! Adapted to new overlayfs mount syntax.

1 files changed, 42 insertions, 10 deletions

diff --git a/remote/includes/chroot.inc b/remote/includes/chroot.inc
index 146d7e7e..5461898f 100644
--- a/remote/includes/chroot.inc
+++ b/remote/includes/chroot.inc
@@ -21,20 +21,27 @@ declare -rg CHROOT_BINDDIR="${CHROOT_TEMPDIR}/rootbind"
 declare -rg CHROOT_LOWERDIR="/"
 declare -rg CHROOT_BINDMOUNTS="/dev /proc /sys /run"
 
+
 # Helper function to setup the directory structure
 chroot_prepare_dirs() {
 	# first check if CHROOT_TEMPDIR exists
 	if [ -d "${CHROOT_TEMPDIR}" ]; then
 		# try to umount and rmdir CHROOT_MOUNTDIR
 		umount "${CHROOT_MOUNTDIR}" 2>/dev/null
-		rmdir "${CHROOT_MOUNTDIR}" || perror "Could not remove '${CHROOT_MOUNTDIR}', meaning it has stuff in it. Aborting..."
+		if [ -d "${CHROOT_MOUNTDIR}" ]; then
+			rmdir "${CHROOT_MOUNTDIR}" || perror "Could not remove CHROOT_MOUNTDIR '${CHROOT_MOUNTDIR}', meaning it has stuff in it. Aborting..."
+		fi
 
 		# try to umount and rmdir CHROOT_BINDDIR
 		umount "${CHROOT_BINDDIR}" 2>/dev/null
-		rmdir "${CHROOT_BINDDIR}" || perror "Could not remove '${CHROOT_BINDDIR}', meaning it has stuff in it. Aborting..."
+		if [ -d "${CHROOT_BINDDIR}" ]; then
+		 	rmdir "${CHROOT_BINDDIR}" || perror "Could not remove CHROOT_BINDDIR '${CHROOT_BINDDIR}', meaning it has stuff in it. Aborting..."
+		fi
 
 		# try to rmdir CHROOT_TEMPDIR
-		rmdir "${CHROOT_TEMPDIR}" || perror "Could not remove '${CHROOT_TEMPDIR}', meaning it has stuff in it. Aborting..."
+		if [ -d "${CHROOT_TEMPDIR}" ]; then
+			rmdir "${CHROOT_TEMPDIR}" || perror "Could not remove CHROOT_TEMPDIR '${CHROOT_TEMPDIR}', meaning it has stuff in it. Aborting..."
+		fi
 	fi
 
 	mkdir -p "${CHROOT_TEMPDIR}"	|| perror "Could not create base directory for mount directories $CHROOT_TEMPDIR."
@@ -50,20 +57,36 @@ chroot_prepare_dirs() {
 chroot_prepare_mounts() {
 
 	# first mount / on CHROOT_BINDDIR and remount read-only
-	mount -o bind "${CHROOT_LOWERDIR}" "${CHROOT_BINDDIR}"	|| perror "Could not bind-mount '$CHROOT_LOWERDIR' to '$CHROOT_BINDDIR'."
-	mount -o remount,ro,bind "${CHROOT_BINDDIR}"		|| perror "Could not remount '$CHROOT_BINDDIR' read-only."
+	mount -o bind "${CHROOT_LOWERDIR}" "${CHROOT_BINDDIR}" \
+			|| perror "Could not bind-mount CHROOT_LOWERDIR '$CHROOT_LOWERDIR' to CHROOT_BINDDIR '$CHROOT_BINDDIR'."
+	mount -o remount,ro,bind "${CHROOT_BINDDIR}"		|| perror "Could not remount CHROOT_BINDDIR '$CHROOT_BINDDIR' read-only."
 
 	# check that it really is read-only
-	[ "x$(mount | grep -E "^/ on ${CHROOT_BINDDIR}" | grep -v '\(.*ro.*\)')" != "x" ] && perror "'${CHROOT_BINDDIR}' is not read-only! Aborting..."
+	[ "x$(mount | grep -E "^/ on ${CHROOT_BINDDIR}" | grep -v '\(.*ro.*\)')" != "x" ] \
+			&& perror "CHROOT_BINDDIR '${CHROOT_BINDDIR}' is not read-only! Aborting..."
 
 	# safe, go on to make the overlay
-	mount -t overlayfs overlayfs -o lowerdir="${CHROOT_BINDDIR}",upperdir="${CHROOT_UPPERDIR}" "${CHROOT_MOUNTDIR}"  \
-		|| perror "Could not mount (overlayfs) $CHROOT_LOWERDIR, $CHROOT_UPPERDIR to $CHROOT_BINDDIR."
+	pinfo "Now mounting overlayfs. Trying old mount syntax (up to Kernel 3.13) ..."
+	mount -t overlayfs overlayfs -o lowerdir="${CHROOT_BINDDIR}",upperdir="${CHROOT_UPPERDIR}" "${CHROOT_MOUNTDIR}" 2>/dev/null
+	if [ $? -ne 0 ]; then
+		pinfo "Old mount syntax failed. Trying mount syntax (Kernel 3.19+) ..."
+		# We have to use a overlayfs workdir which _must_ be on the same filesystem as CHROOT_UPPERDIR. So
+		# we traverse to the directory below CHROOT_UPPERDIR and mkdir/mktemp a workdir there. In the possible
+		# case that CHROOT_UPPERDIR is the root dir of a filesystem there's nothing we can do.
+		CHROOT_WORKDIR="$(mktemp -d $(dirname ${CHROOT_UPPERDIR})/workdirXXX)" \
+			|| perror "Could not mkdir overlayfs workdir $CHROOT_WORKDIR for new overlayfs mount syntax."
+		# Now we try to mount the overlayfs in the new fashion:
+		mount -t overlayfs overlayfs -o lowerdir="$CHROOT_LOWERDIR",upperdir="${CHROOT_UPPERDIR}",workdir="${CHROOT_WORKDIR}" "${CHROOT_MOUNTDIR}" \
+			|| perror "Could not mount (overlayfs) $CHROOT_LOWERDIR, $CHROOT_UPPERDIR to $CHROOT_BINDDIR."
+		pinfo "New overlayfs mount syntax has worked, commencing."
+	else
+		pinfo "Old overlayfs mount syntax has worked, commencing."
+	fi
 
-	# mount pseudo-filesystems
+	#  mount pseudo-filesystems
 	for DIR in $CHROOT_BINDMOUNTS; do
 		mount -o bind "${DIR}" "${CHROOT_MOUNTDIR}/${DIR}" \
-			|| perror "Could not bind mount '$DIR' into '$CHROOT_MOUNTDIR/$DIR'."
+			|| perror "Could not bind mount '$DIR' into CHROOT_MOUNTDIR/DIR '$CHROOT_MOUNTDIR/$DIR'."
 	done
 }
 
@@ -211,4 +234,13 @@ chroot_cleanup_mounts() {
 	else
 		pinfo "Nothing chroot-related is mounted - exiting."
 	fi
+
+	if [ -d "${CHROOT_WORKDIR}" ]; then
+		# Too much of a coward to rm -rf somewhere. Both directories have to be empty so we use rmdir.
+		rmdir "${CHROOT_WORKDIR}/work" && pinfo "rmdir-ed CHROOT_WORKDIR/work ${CHROOT_WORKDIR}/work needed for new overlayfs mount syntax." \
+				|| pinfo "Could not rmdir CHROOT_WORKDIR/work ${CHROOT_WORKDIR}/work - clean it by hand."
+		rmdir "${CHROOT_WORKDIR}" && pinfo "rmdir-ed CHROOT_WORKDIR ${CHROOT_WORKDIR} needed for new overlayfs mount syntax." \
+				  || pinfo "Could not rmdir CHROOT_WORKDIR ${CHROOT_WORKDIR} needed for new overlayfs mount syntax - clean by hand."
+		umount overlayfs
+	fi
 }