From f4319096d31207185ba94a0b997109597dc56791 Mon Sep 17 00:00:00 2001
From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Tue, 14 Jul 2020 15:49:14 +0200
Subject: [PATCH 1/3] Do not hardcode /mnt/clone in rpi-clone-setup

Instead, pass the mount location through an environment variable.
---
 rpi-clone       |  6 +++---
 rpi-clone-setup | 20 ++++++++++++++------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/rpi-clone b/rpi-clone
index b6baf53..237e9f1 100755
--- a/rpi-clone
+++ b/rpi-clone
@@ -85,9 +85,9 @@ then
 	apt-get install -y --no-install-recommends $need_packages
 fi
 
-clone=/mnt/clone
-clone_src=/mnt/clone-src
-clone_log=/var/log/$PGM.log
+export clone=/mnt/clone
+export clone_src=/mnt/clone-src
+export clone_log=/var/log/$PGM.log
 
 HOSTNAME=`hostname`
 
diff --git a/rpi-clone-setup b/rpi-clone-setup
index 5578c30..b8b4558 100755
--- a/rpi-clone-setup
+++ b/rpi-clone-setup
@@ -4,11 +4,13 @@
 #    eg:  sudo rpi-clone-setup bozo
 #
 # This script is automatically run by rpi-clone (when it is given -s options)
-# to setup an alternate hostname.  A cloned file system mounted on /mnt/clone
-# is expected unless testing with the -t option.
+# to setup an alternate hostname.  It expects $clone to be set in the
+# environment containing the path to a mounted cloned file system unless
+# testing with the -t option.
 #
 # Or, this script can be run by hand at the end of a clone when rpi-clone
-# pauses with the cloned file systems still mounted on /mnt/clone.
+# pauses with the cloned file systems still mounted (make sure to set
+# the $clone env variable properly, then).
 #
 # Or, run this script by hand with -t to process files in test directories
 # under /tmp/clone-test.  Run -t and look at the files to see if the files
@@ -27,7 +29,7 @@
 
 file_list="etc/hostname etc/hosts"
 
-clone=/mnt/clone
+# $clone is set by caller
 clone_test=/tmp/clone-test
 
 PGM=`basename $0`
@@ -81,9 +83,15 @@ fi
 
 echo -e "\t$newhost\t- target hostname"
 
-if ((!testing)) && [ ! -d /mnt/clone/etc ]
+if ((!testing)) && [ -z "$clone" ]
 then
-	echo "A destination clone file system is not mounted on /mnt/clone"
+	echo "No clone mountpoint was passed in the \$clone variable"
+	echo "Aborting!"
+	exit 0
+fi
+if ((!testing)) && [ ! -d "$clone/etc" ]
+then
+	echo "A destination clone file system is not mounted on $clone"
 	echo "Aborting!"
 	exit 0
 fi

From 5294c9b91119715b7bb6cd0e4e55ee2bf274a7cb Mon Sep 17 00:00:00 2001
From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Tue, 14 Jul 2020 15:56:19 +0200
Subject: [PATCH 2/3] Create mount directories earlier

The `$clone` directory is already used when figuring out disk space for
unmounted partitions, so this could fail on the first run.
---
 rpi-clone | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/rpi-clone b/rpi-clone
index 237e9f1..8bacdd1 100755
--- a/rpi-clone
+++ b/rpi-clone
@@ -993,6 +993,15 @@ then
 	exit 0
 fi
 
+if [ ! -d $clone ]
+then
+	mkdir $clone
+fi
+if [ ! -d $clone_src ]
+then
+	mkdir $clone_src
+fi
+
 # dst_mount_flag enumerations:
 live=1
 temp=2
@@ -1248,16 +1257,6 @@ unmount_or_abort "$mounted_dev" \
 mounted_dev=$(findmnt /mnt -o source -n)
 unmount_or_abort "$mounted_dev" "$mounted_dev is currently mounted on /mnt."
 
-
-if [ ! -d $clone ]
-then
-	mkdir $clone
-fi
-if [ ! -d $clone_src ]
-then
-	mkdir $clone_src
-fi
-
 # Do not include a dhpys swapfile in rsync.  It regenerates at boot.
 #
 if [ -f /etc/dphys-swapfile ]

From 36382051a3eb9aba95819c8b830ef09da68410f0 Mon Sep 17 00:00:00 2001
From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Tue, 14 Jul 2020 15:49:49 +0200
Subject: [PATCH 3/3] Use a random temp directory for mounting

This allows using the script multiple times in parallel on different
disks.

To prevent all these directories littering the filesystem, an exit
handler is registered to remove them again when the script exits (also
unmounting any mounted filesystems just in case).
---
 rpi-clone | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/rpi-clone b/rpi-clone
index 8bacdd1..2d6116d 100755
--- a/rpi-clone
+++ b/rpi-clone
@@ -85,8 +85,6 @@ then
 	apt-get install -y --no-install-recommends $need_packages
 fi
 
-export clone=/mnt/clone
-export clone_src=/mnt/clone-src
 export clone_log=/var/log/$PGM.log
 
 HOSTNAME=`hostname`
@@ -993,15 +991,25 @@ then
 	exit 0
 fi
 
-if [ ! -d $clone ]
-then
-	mkdir $clone
-fi
-if [ ! -d $clone_src ]
+export clone=$(mktemp --tmpdir --directory rpi-clone-dst.XXXXXX)
+export clone_src=$(mktemp --tmpdir --directory rpi-clone-src.XXXXXX)
+
+if ! [ -n "$clone" -a -d "$clone" -a -n "$clone_src" -a -d "$clone_src" ]
 then
-	mkdir $clone_src
+	echo "Failed to create temporary mount directories"
+	echo "Aborting!"
+	exit 1
 fi
 
+# Make sure we cleanup on exit, regardless of how we exit
+cleanup() {
+	umount "$clone" 2> /dev/null
+	umount "$clone_src" 2> /dev/null
+	rmdir "$clone"
+	rmdir "$clone_src"
+}
+trap cleanup EXIT
+
 # dst_mount_flag enumerations:
 live=1
 temp=2