From 22cc994d11247b04c74afc97bc37b09db5256621 Mon Sep 17 00:00:00 2001
From: Saverio Miroddi <saverio.pub2@gmail.com>
Date: Tue, 27 Apr 2021 12:40:57 +0200
Subject: [PATCH 1/6] Cosmetic improvement to distro_dependent_invoke()

---
 install-zfs.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/install-zfs.sh b/install-zfs.sh
index b14248f..c081407 100755
--- a/install-zfs.sh
+++ b/install-zfs.sh
@@ -129,11 +129,12 @@ c_udevadm_settle_timeout=10 # seconds
 #
 function distro_dependent_invoke {
   local distro_specific_fx_name="$1_$v_linux_distribution"
+  local invoke_option=${2:-}
 
   if declare -f "$distro_specific_fx_name" > /dev/null; then
     "$distro_specific_fx_name"
   else
-    if ! declare -f "$1" > /dev/null && [[ "${2:-}" == "--noforce" ]]; then
+    if ! declare -f "$1" > /dev/null && [[ $invoke_option == "--noforce" ]]; then
       : # do nothing
     else
       "$1"

From c7c0f530f8f137797602578f7e14ddd991ac12b5 Mon Sep 17 00:00:00 2001
From: Saverio Miroddi <saverio.pub2@gmail.com>
Date: Tue, 27 Apr 2021 12:48:05 +0200
Subject: [PATCH 2/6] distro_dependent_invoke(): Add option checking

---
 install-zfs.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/install-zfs.sh b/install-zfs.sh
index c081407..a710bf5 100755
--- a/install-zfs.sh
+++ b/install-zfs.sh
@@ -131,6 +131,11 @@ function distro_dependent_invoke {
   local distro_specific_fx_name="$1_$v_linux_distribution"
   local invoke_option=${2:-}
 
+  if [[ ! $invoke_option =~ ^(|--noforce)$ ]]; then
+    >&2 echo "Invalid distro_dependent_invoke() option: $invoke_option"
+    exit 1
+  fi
+
   if declare -f "$distro_specific_fx_name" > /dev/null; then
     "$distro_specific_fx_name"
   else

From ad7f09fbb4d0c6f648323eb69a1a937b9be3cc01 Mon Sep 17 00:00:00 2001
From: Saverio Miroddi <saverio.pub2@gmail.com>
Date: Tue, 27 Apr 2021 13:10:03 +0200
Subject: [PATCH 3/6] New function invocation mechanism (README!)

The new mechanism is clearly explained in the comment. The rationale is the next implementation of hot swapping.

WATCH OUT! The semantics have changed. Previously, it was evident by looking at the invocation when a function had distro-based overrides; now, that needs to be looked into. Since this behavior is not very impactful, it's not been ported, for simplicity purposes.
---
 install-zfs.sh | 134 +++++++++++++++++++++++++------------------------
 1 file changed, 69 insertions(+), 65 deletions(-)

diff --git a/install-zfs.sh b/install-zfs.sh
index a710bf5..f63f11c 100755
--- a/install-zfs.sh
+++ b/install-zfs.sh
@@ -107,43 +107,47 @@ c_udevadm_settle_timeout=10 # seconds
 
 # HELPER FUNCTIONS #############################################################
 
-# Chooses a function and invokes it depending on the O/S distribution.
+# Invoke a function, with a primitive dynamic dispatch based on the distribution.
 #
-# Example:
+# Format: `invoke "function" [--optional]`.
+#
+# A target function must exist, otherwise a error is raised, unless `--optional` is specified.
+# `--optional` is useful when a step is specific to a single distribution, e.g. Debian's root password.
+#
+# Examples:
 #
 #   $ function install_jail_zfs_packages { :; }
 #   $ function install_jail_zfs_packages_Debian { :; }
 #   $ distro_dependent_invoke "install_jail_zfs_packages"
 #
-# If the distribution is `Debian`, the second will be invoked, otherwise, the
-# first.
-#
-# If the function is invoked with `--noforce` as second parameter, and there is
-# no matching function:
+#   If the distribution is `Debian`, the second will be invoked, otherwise, the first.
 #
 #   $ function update_zed_cache_Ubuntu { :; }
-#   $ distro_dependent_invoke "install_jail_zfs_packages" --noforce
+#   $ distro_dependent_invoke "update_zed_cache" --optional
 #
-# then nothing happens. Without `--noforce`, this invocation will cause an
-# error.
+#   If the distribution is `Debian`, nothing will happen.
 #
-function distro_dependent_invoke {
-  local distro_specific_fx_name="$1_$v_linux_distribution"
+#   $ function update_zed_cache_Ubuntu { :; }
+#   $ distro_dependent_invoke "update_zed_cache"
+#
+#   If the distribution is `Debian`, an error will be raised.
+#
+function invoke {
+  local base_fx_name=$1
+  local distro_specific_fx_name=$1_$v_linux_distribution
   local invoke_option=${2:-}
 
-  if [[ ! $invoke_option =~ ^(|--noforce)$ ]]; then
-    >&2 echo "Invalid distro_dependent_invoke() option: $invoke_option"
+  if [[ ! $invoke_option =~ ^(|--optional)$ ]]; then
+    >&2 echo "Invalid invoke() option: $invoke_option"
     exit 1
   fi
 
+  # Invoke it regardless when it's not optional.
+
   if declare -f "$distro_specific_fx_name" > /dev/null; then
     "$distro_specific_fx_name"
-  else
-    if ! declare -f "$1" > /dev/null && [[ $invoke_option == "--noforce" ]]; then
-      : # do nothing
-    else
-      "$1"
-    fi
+  elif declare -f "$base_fx_name" > /dev/null || [[ ! $invoke_option == "--optional" ]]; then
+    "$base_fx_name"
   fi
 }
 
@@ -1502,59 +1506,59 @@ if [[ $# -ne 0 ]]; then
   display_help_and_exit
 fi
 
-activate_debug
-set_distribution_data
-distro_dependent_invoke "store_os_distro_information"
-store_running_processes
-check_prerequisites
-display_intro_banner
-check_system_memory
-save_disks_log
-find_suitable_disks
-distro_dependent_invoke "set_zfs_ppa_requirement"
-register_exit_hook
-create_passphrase_named_pipe
+invoke "activate_debug"
+invoke "set_distribution_data"
+invoke "store_os_distro_information"
+invoke "store_running_processes"
+invoke "check_prerequisites"
+invoke "display_intro_banner"
+invoke "check_system_memory"
+invoke "save_disks_log"
+invoke "find_suitable_disks"
+invoke "set_zfs_ppa_requirement"
+invoke "register_exit_hook"
+invoke "create_passphrase_named_pipe"
 
-select_disks
-select_pools_raid_type
-distro_dependent_invoke "ask_root_password" --noforce
-ask_encryption
-ask_boot_partition_size
-ask_swap_size
-ask_free_tail_space
-ask_rpool_name
-ask_pool_create_options
+invoke "select_disks"
+invoke "select_pools_raid_type"
+invoke "ask_root_password" --optional
+invoke "ask_encryption"
+invoke "ask_boot_partition_size"
+invoke "ask_swap_size"
+invoke "ask_free_tail_space"
+invoke "ask_rpool_name"
+invoke "ask_pool_create_options"
 
-distro_dependent_invoke "install_host_packages"
-setup_partitions
+invoke "install_host_packages"
+invoke "setup_partitions"
 
 if [[ "${ZFS_OS_INSTALLATION_SCRIPT:-}" == "" ]]; then
   # Includes the O/S extra configuration, if necessary (network, root pwd, etc.)
-  distro_dependent_invoke "install_operating_system"
+  invoke "install_operating_system"
 
-  create_pools
-  create_swap_volume
-  copy_zpool_cache
-  sync_os_temp_installation_dir_to_rpool
-  remove_temp_partition_and_expand_rpool
+  invoke "create_pools"
+  invoke "create_swap_volume"
+  invoke "copy_zpool_cache"
+  invoke "sync_os_temp_installation_dir_to_rpool"
+  invoke "remove_temp_partition_and_expand_rpool"
 else
-  create_pools
-  create_swap_volume
-  copy_zpool_cache
-  remove_temp_partition_and_expand_rpool
+  invoke "create_pools"
+  invoke "create_swap_volume"
+  invoke "copy_zpool_cache"
+  invoke "remove_temp_partition_and_expand_rpool"
 
-  custom_install_operating_system
+  invoke "custom_install_operating_system"
 fi
 
-prepare_jail
-distro_dependent_invoke "install_jail_zfs_packages"
-prepare_efi_partition
-configure_and_update_grub
-sync_efi_partitions
-update_initramfs
-fix_filesystem_mount_ordering
-configure_pools_trimming
-configure_remaining_settings
+invoke "prepare_jail"
+invoke "install_jail_zfs_packages"
+invoke "prepare_efi_partition"
+invoke "configure_and_update_grub"
+invoke "sync_efi_partitions"
+invoke "update_initramfs"
+invoke "fix_filesystem_mount_ordering"
+invoke "configure_pools_trimming"
+invoke "configure_remaining_settings"
 
-prepare_for_system_exit
-display_exit_banner
+invoke "prepare_for_system_exit"
+invoke "display_exit_banner"

From 3cbc9ff207d40b0d65dcf2a200b1ceb9e0f4255a Mon Sep 17 00:00:00 2001
From: Saverio Miroddi <saverio.pub2@gmail.com>
Date: Tue, 27 Apr 2021 13:17:18 +0200
Subject: [PATCH 4/6] Refactoring: The info header function is now invoked by
 invoke()

---
 install-zfs.sh | 107 ++++---------------------------------------------
 1 file changed, 7 insertions(+), 100 deletions(-)

diff --git a/install-zfs.sh b/install-zfs.sh
index f63f11c..ace38fd 100755
--- a/install-zfs.sh
+++ b/install-zfs.sh
@@ -145,21 +145,22 @@ function invoke {
   # Invoke it regardless when it's not optional.
 
   if declare -f "$distro_specific_fx_name" > /dev/null; then
+    print_step_info_header "$distro_specific_fx_name"
+
     "$distro_specific_fx_name"
   elif declare -f "$base_fx_name" > /dev/null || [[ ! $invoke_option == "--optional" ]]; then
+    print_step_info_header "$base_fx_name"
+
     "$base_fx_name"
   fi
 }
 
-# shellcheck disable=SC2120 # allow parameters passing even if no calls pass any
 function print_step_info_header {
+  local function_name=$1
+
   echo -n "
 ###############################################################################
-# ${FUNCNAME[1]}"
-
-  [[ "${1:-}" != "" ]] && echo -n " $1" || true
-
-  echo "
+# $function_name
 ###############################################################################
 "
 }
@@ -241,8 +242,6 @@ Root pool default create options: '"${c_default_rpool_create_options[*]/#-/$'\n'
 }
 
 function activate_debug {
-  print_step_info_header
-
   mkdir -p "$c_log_dir"
 
   exec 5> "$c_install_log"
@@ -261,8 +260,6 @@ function set_distribution_data {
 }
 
 function store_os_distro_information {
-  print_step_info_header
-
   lsb_release --all > "$c_os_information_log"
 
   # Madness, in order not to force the user to invoke "sudo -E".
@@ -286,8 +283,6 @@ function store_running_processes {
 }
 
 function check_prerequisites {
-  print_step_info_header
-
   local distro_version_regex=\\b${v_linux_version//./\\.}\\b
 
   if [[ ! -d /sys/firmware/efi ]]; then
@@ -318,8 +313,6 @@ function check_prerequisites {
 }
 
 function display_intro_banner {
-  print_step_info_header
-
   local dialog_message='Hello!
 
 This script will prepare the ZFS pools on the system, install Ubuntu, and configure the boot.
@@ -351,8 +344,6 @@ In such cases, the module building may fail abruptly, either without visible err
 }
 
 function save_disks_log {
-  print_step_info_header
-
   # shellcheck disable=SC2012 # `ls` may clean the output, but in this case, it doesn't matter
   ls -l /dev/disk/by-id | tail -n +2 | perl -lane 'print "@F[8..10]"' > "$c_disks_log"
 
@@ -370,8 +361,6 @@ LOG
 }
 
 function find_suitable_disks {
-  print_step_info_header
-
   # In some freaky cases, `/dev/disk/by-id` is not up to date, so we refresh. One case is after
   # starting a VirtualBox VM that is a full clone of a suspended VM with snapshots.
   #
@@ -436,8 +425,6 @@ If you think this is a bug, please open an issue on https://github.com/saveriomi
 # install_host_packages() and install_host_packages_UbuntuServer().
 #
 function set_zfs_ppa_requirement {
-  print_step_info_header
-
   apt update
 
   local zfs_package_version
@@ -460,8 +447,6 @@ function set_zfs_ppa_requirement_Debian {
 # to it being incorrectly setup).
 #
 function set_zfs_ppa_requirement_Linuxmint {
-  print_step_info_header
-
   perl -i -pe 's/^(deb cdrom)/# $1/' /etc/apt/sources.list
 
   set_zfs_ppa_requirement
@@ -471,14 +456,10 @@ function set_zfs_ppa_requirement_Linuxmint {
 # from the logs.
 #
 function create_passphrase_named_pipe {
-  print_step_info_header
-
   mkfifo "$c_passphrase_named_pipe"
 }
 
 function register_exit_hook {
-  print_step_info_header
-
   function _exit_hook {
     rm -f "$c_passphrase_named_pipe"
 
@@ -527,8 +508,6 @@ export ZFS_FREE_TAIL_SPACE=12
 }
 
 function select_disks {
-  print_step_info_header
-
   if [[ "${ZFS_SELECTED_DISKS:-}" != "" ]]; then
     mapfile -d, -t v_selected_disks < <(echo -n "$ZFS_SELECTED_DISKS")
   else
@@ -568,8 +547,6 @@ Devices with mounted partitions, cdroms, and removable devices are not displayed
 }
 
 function select_pools_raid_type {
-  print_step_info_header
-
   local raw_pools_raid_type=
 
   if [[ -v ZFS_POOLS_RAID_TYPE ]]; then
@@ -613,8 +590,6 @@ function select_pools_raid_type {
 }
 
 function ask_root_password_Debian {
-  print_step_info_header
-
   set +x
   if [[ ${ZFS_DEBIAN_ROOT_PASSWORD:-} != "" ]]; then
     v_root_password="$ZFS_DEBIAN_ROOT_PASSWORD"
@@ -633,8 +608,6 @@ function ask_root_password_Debian {
 }
 
 function ask_encryption {
-  print_step_info_header
-
   set +x
 
   if [[ -v ZFS_PASSPHRASE ]]; then
@@ -665,8 +638,6 @@ Leave blank to keep encryption disabled.
 }
 
 function ask_boot_partition_size {
-  print_step_info_header
-
   if [[ ${ZFS_BOOT_PARTITION_SIZE:-} != "" ]]; then
     v_boot_partition_size=$ZFS_BOOT_PARTITION_SIZE
   else
@@ -685,8 +656,6 @@ Supported formats: '512M', '3G'" 30 100 ${c_default_boot_partition_size}M 3>&1 1
 }
 
 function ask_swap_size {
-  print_step_info_header
-
   if [[ ${ZFS_SWAP_SIZE:-} != "" ]]; then
     v_swap_size=$ZFS_SWAP_SIZE
   else
@@ -703,8 +672,6 @@ function ask_swap_size {
 }
 
 function ask_free_tail_space {
-  print_step_info_header
-
   if [[ ${ZFS_FREE_TAIL_SPACE:-} != "" ]]; then
     v_free_tail_space=$ZFS_FREE_TAIL_SPACE
   else
@@ -729,8 +696,6 @@ For detailed informations, see the wiki page: https://github.com/saveriomiroddi/
 }
 
 function ask_rpool_name {
-  print_step_info_header
-
   if [[ ${ZFS_RPOOL_NAME:-} != "" ]]; then
     v_rpool_name=$ZFS_RPOOL_NAME
   else
@@ -747,8 +712,6 @@ function ask_rpool_name {
 }
 
 function ask_pool_create_options {
-  print_step_info_header
-
   local bpool_create_options_message='Insert the create options for the boot pool
 
 The mount-related options are automatically added, and must not be specified.'
@@ -769,8 +732,6 @@ The encryption/mount-related options are automatically added, and must not be sp
 }
 
 function install_host_packages {
-  print_step_info_header
-
   if [[ $v_use_ppa == "1" ]]; then
     if [[ ${ZFS_SKIP_LIVE_ZFS_MODULE_INSTALL:-} != "1" ]]; then
       add-apt-repository --yes "$c_ppa"
@@ -795,8 +756,6 @@ function install_host_packages {
 }
 
 function install_host_packages_Debian {
-  print_step_info_header
-
   if [[ ${ZFS_SKIP_LIVE_ZFS_MODULE_INSTALL:-} != "1" ]]; then
     echo "zfs-dkms zfs-dkms/note-incompatible-licenses note true" | debconf-set-selections
 
@@ -817,16 +776,12 @@ function install_host_packages_Debian {
 # Differently from Ubuntu, Mint doesn't have the package installed in the live version.
 #
 function install_host_packages_Linuxmint {
-  print_step_info_header
-
   apt install --yes zfsutils-linux
 
   install_host_packages
 }
 
 function install_host_packages_elementary {
-  print_step_info_header
-
   if [[ ${ZFS_SKIP_LIVE_ZFS_MODULE_INSTALL:-} != "1" ]]; then
     apt update
     apt install --yes software-properties-common
@@ -836,8 +791,6 @@ function install_host_packages_elementary {
 }
 
 function install_host_packages_UbuntuServer {
-  print_step_info_header
-
   if [[ $v_use_ppa != "1" ]]; then
     apt install --yes zfsutils-linux efibootmgr
 
@@ -869,8 +822,6 @@ function install_host_packages_UbuntuServer {
 }
 
 function setup_partitions {
-  print_step_info_header
-
   local required_tail_space=$((v_free_tail_space > c_temporary_volume_size ? v_free_tail_space : c_temporary_volume_size))
 
   for selected_disk in "${v_selected_disks[@]}"; do
@@ -926,8 +877,6 @@ function setup_partitions {
 }
 
 function install_operating_system {
-  print_step_info_header
-
   local dialog_message='The Ubuntu GUI installer will now be launched.
 
 Proceed with the configuration as usual, then, at the partitioning stage:
@@ -969,8 +918,6 @@ Proceed with the configuration as usual, then, at the partitioning stage:
 }
 
 function install_operating_system_Debian {
-  print_step_info_header
-
   # The temporary volume size displayed is an approximation of the format used by the installer,
   # but it's acceptable - the complexity required is not worth (eg. converting hypothetical units,
   # etc.).
@@ -1023,8 +970,6 @@ CONF
 }
 
 function install_operating_system_UbuntuServer {
-  print_step_info_header
-
   # O/S Installation
   #
   # Subiquity is designed to prevent the user from opening a terminal, which is (to say the least)
@@ -1066,8 +1011,6 @@ You can switch anytime to this terminal, and back, in order to read the instruct
 }
 
 function custom_install_operating_system {
-  print_step_info_header
-
   sudo "$ZFS_OS_INSTALLATION_SCRIPT"
 }
 
@@ -1118,8 +1061,6 @@ function create_pools {
 }
 
 function create_swap_volume {
-  print_step_info_header
-
   if [[ $v_swap_size -gt 0 ]]; then
     zfs create \
       -V "${v_swap_size}G" -b "$(getconf PAGESIZE)" \
@@ -1131,15 +1072,11 @@ function create_swap_volume {
 }
 
 function copy_zpool_cache {
-  print_step_info_header
-
   mkdir -p "$c_zfs_mount_dir/etc/zfs"
   cp /etc/zfs/zpool.cache "$c_zfs_mount_dir/etc/zfs/"
 }
 
 function sync_os_temp_installation_dir_to_rpool {
-  print_step_info_header
-
   # On Ubuntu Server, `/boot/efi` and `/cdrom` (!!!) are mounted, but they're not needed.
   #
   local mount_dir_submounts
@@ -1172,8 +1109,6 @@ function sync_os_temp_installation_dir_to_rpool {
 }
 
 function remove_temp_partition_and_expand_rpool {
-  print_step_info_header
-
   if (( v_free_tail_space < c_temporary_volume_size )); then
     if [[ $v_free_tail_space -eq 0 ]]; then
       local resize_reference=100%
@@ -1208,8 +1143,6 @@ function remove_temp_partition_and_expand_rpool {
 }
 
 function prepare_jail {
-  print_step_info_header
-
   for virtual_fs_dir in proc sys dev; do
     mount --rbind "/$virtual_fs_dir" "$c_zfs_mount_dir/$virtual_fs_dir"
   done
@@ -1220,8 +1153,6 @@ function prepare_jail {
 # See install_host_packages() for some comments.
 #
 function install_jail_zfs_packages {
-  print_step_info_header
-
   if [[ $v_use_ppa == "1" ]]; then
     chroot_execute "add-apt-repository --yes $c_ppa"
 
@@ -1246,8 +1177,6 @@ function install_jail_zfs_packages {
 }
 
 function install_jail_zfs_packages_Debian {
-  print_step_info_header
-
   chroot_execute 'echo "deb http://deb.debian.org/debian buster main contrib"     >> /etc/apt/sources.list'
   chroot_execute 'echo "deb-src http://deb.debian.org/debian buster main contrib" >> /etc/apt/sources.list'
 
@@ -1267,16 +1196,12 @@ APT'
 }
 
 function install_jail_zfs_packages_elementary {
-  print_step_info_header
-
   chroot_execute "apt install --yes software-properties-common"
 
   install_jail_zfs_packages
 }
 
 function install_jail_zfs_packages_UbuntuServer {
-  print_step_info_header
-
   if [[ $v_use_ppa != "1" ]]; then
     chroot_execute "apt install --yes zfsutils-linux zfs-initramfs grub-efi-amd64-signed shim-signed"
   else
@@ -1285,8 +1210,6 @@ function install_jail_zfs_packages_UbuntuServer {
 }
 
 function prepare_efi_partition {
-  print_step_info_header
-
   # The other mounts are configured/synced in the EFI partitions sync stage.
   #
   chroot_execute "echo /dev/disk/by-uuid/$(blkid -s UUID -o value "${v_selected_disks[0]}"-part1) /boot/efi vfat defaults 0 0 > /etc/fstab"
@@ -1298,8 +1221,6 @@ function prepare_efi_partition {
 }
 
 function configure_and_update_grub {
-  print_step_info_header
-
   chroot_execute "perl -i -pe 's/GRUB_CMDLINE_LINUX_DEFAULT=\"\K/init_on_alloc=0 /'        /etc/default/grub"
 
   # Silence warning during the grub probe (source: https://git.io/JenXF).
@@ -1326,8 +1247,6 @@ function configure_and_update_grub {
 }
 
 function sync_efi_partitions {
-  print_step_info_header
-
   for ((i = 1; i < ${#v_selected_disks[@]}; i++)); do
     local synced_efi_partition_path="/boot/efi$((i + 1))"
 
@@ -1350,14 +1269,10 @@ function sync_efi_partitions {
 # See issue https://github.com/saveriomiroddi/zfs-installer/issues/110.
 #
 function update_initramfs {
-  print_step_info_header
-
   chroot_execute "update-initramfs -u"
 }
 
 function fix_filesystem_mount_ordering {
-  print_step_info_header
-
   chroot_execute "mkdir /etc/zfs/zfs-list.cache"
   chroot_execute "touch /etc/zfs/zfs-list.cache/$c_bpool_name /etc/zfs/zfs-list.cache/$v_rpool_name"
 
@@ -1416,8 +1331,6 @@ function fix_filesystem_mount_ordering {
 # The code is a straight copy of the `fstrim` service.
 #
 function configure_pools_trimming {
-  print_step_info_header
-
   chroot_execute "cat > /lib/systemd/system/zfs-trim.service << UNIT
 [Unit]
 Description=Discard unused ZFS blocks
@@ -1448,15 +1361,11 @@ TIMER"
 }
 
 function configure_remaining_settings {
-  print_step_info_header
-
   [[ $v_swap_size -gt 0 ]] && chroot_execute "echo /dev/zvol/$v_rpool_name/swap none swap discard 0 0 >> /etc/fstab" || true
   chroot_execute "echo RESUME=none > /etc/initramfs-tools/conf.d/resume"
 }
 
 function prepare_for_system_exit {
-  print_step_info_header
-
   for virtual_fs_dir in dev sys proc; do
     umount --recursive --force --lazy "$c_zfs_mount_dir/$virtual_fs_dir"
   done
@@ -1489,8 +1398,6 @@ function prepare_for_system_exit {
 }
 
 function display_exit_banner {
-  print_step_info_header
-
   local dialog_message="The system has been successfully prepared and installed.
 
 You now need to perform a hard reset, then enjoy your ZFS system :-)"

From e176be6521eac9d799e597b80a363ac80bfeecce Mon Sep 17 00:00:00 2001
From: Saverio Miroddi <saverio.pub2@gmail.com>
Date: Tue, 27 Apr 2021 13:22:54 +0200
Subject: [PATCH 5/6] Add script hot swapping functionality

---
 install-zfs.sh | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/install-zfs.sh b/install-zfs.sh
index ace38fd..3877090 100755
--- a/install-zfs.sh
+++ b/install-zfs.sh
@@ -43,6 +43,8 @@ v_suitable_disks=()          # (/dev/by-id/disk_id, ...); scope: find_suitable_d
 # Note that Linux Mint is "Linuxmint" from v20 onwards. This actually helps, since some operations are
 # specific to it.
 
+c_hotswap_file=$PWD/install-zfs.hotswap.sh # see hotswap() for an explanation.
+
 c_bpool_name=bpool
 c_ppa=ppa:jonathonf/zfs
 c_efi_system_partition_size=512 # megabytes
@@ -142,6 +144,8 @@ function invoke {
     exit 1
   fi
 
+  hot_swap_script
+
   # Invoke it regardless when it's not optional.
 
   if declare -f "$distro_specific_fx_name" > /dev/null; then
@@ -155,6 +159,18 @@ function invoke {
   fi
 }
 
+# Tee-hee-hee!!
+#
+# This is extremely useful for debugging long procedures. Since bash scripts can't be modified while
+# running, this allows the dev to create a snapshot, and if the script fails after that, resume and
+# add the hotswap script, so that the new code will be loaded automatically.
+#
+function hot_swap_script {
+  if [[ -f $c_hotswap_file ]]; then
+    source "$c_hotswap_file"
+  fi
+}
+
 function print_step_info_header {
   local function_name=$1
 

From 8363b37cccda29b99c111da402a31b83e2035d3d Mon Sep 17 00:00:00 2001
From: Saverio Miroddi <saverio.pub2@gmail.com>
Date: Tue, 27 Apr 2021 13:43:16 +0200
Subject: [PATCH 6/6] Make the distro-specific functions use invoke(), when
 calling the parent

---
 install-zfs.sh | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/install-zfs.sh b/install-zfs.sh
index 3877090..29bd464 100755
--- a/install-zfs.sh
+++ b/install-zfs.sh
@@ -465,7 +465,7 @@ function set_zfs_ppa_requirement_Debian {
 function set_zfs_ppa_requirement_Linuxmint {
   perl -i -pe 's/^(deb cdrom)/# $1/' /etc/apt/sources.list
 
-  set_zfs_ppa_requirement
+  invoke "set_zfs_ppa_requirement"
 }
 
 # By using a FIFO, we avoid having to hide statements like `echo $v_passphrase | zpoool create ...`
@@ -794,7 +794,7 @@ function install_host_packages_Debian {
 function install_host_packages_Linuxmint {
   apt install --yes zfsutils-linux
 
-  install_host_packages
+  invoke "install_host_packages"
 }
 
 function install_host_packages_elementary {
@@ -803,7 +803,7 @@ function install_host_packages_elementary {
     apt install --yes software-properties-common
   fi
 
-  install_host_packages
+  invoke "install_host_packages"
 }
 
 function install_host_packages_UbuntuServer {
@@ -1214,14 +1214,14 @@ APT'
 function install_jail_zfs_packages_elementary {
   chroot_execute "apt install --yes software-properties-common"
 
-  install_jail_zfs_packages
+  invoke "install_jail_zfs_packages"
 }
 
 function install_jail_zfs_packages_UbuntuServer {
   if [[ $v_use_ppa != "1" ]]; then
     chroot_execute "apt install --yes zfsutils-linux zfs-initramfs grub-efi-amd64-signed shim-signed"
   else
-    install_jail_zfs_packages
+    invoke "install_jail_zfs_packages"
   fi
 }