iankelling.org Git - distro-setup/blob - mount-latest-subvol

   1 #!/bin/bash
   2
   3 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
   4
   5 errcatch() {
   6     set -E; shopt -s extdebug
   7     _err-trap() {
   8         err=$?
   9         exec >&2
  10         set +x
  11         echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}:in \`$BASH_COMMAND' returned $err"
  12         bash-trace 2
  13         echo "$0: exiting with code $err"
  14         exit $err
  15     }
  16     trap _err-trap ERR
  17     set -o pipefail
  18 }
  19 bash-trace() {
  20     local -i argc_index=0 arg frame i start=${1:-1} max_indent=8 indent
  21     local source
  22     local extdebug=false
  23     if [[ $(shopt -p extdebug) == *-s* ]]; then
  24         extdebug=true
  25     fi
  26
  27     for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
  28         argc=${BASH_ARGC[frame]}
  29         argc_index+=$argc
  30         ((frame < start)) && continue
  31         if (( ${#BASH_SOURCE[@]} > 1 )); then
  32             source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
  33         fi
  34         indent=$((frame-start+1))
  35         indent=$((indent < max_indent ? indent : max_indent))
  36         printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
  37         if $extdebug; then
  38             for ((i=argc_index-1; i >= argc_index-argc; i--)); do
  39                 printf " %s" "${BASH_ARGV[i]}"
  40             done
  41         fi
  42         echo \'
  43     done
  44 }
  45 errcatch
  46
  47
  48 e() { printf "%s\n" "$*"; "$@"; }
  49
  50 ret=0
  51
  52 first_root_crypt=$(awk '$2 == "/" {print $1}' /etc/mtab)
  53 tu /etc/fstab <<EOF
  54 $first_root_crypt  /q  btrfs  noatime,subvol=q  0 0
  55 /q/a  /a  none  bind  0 0
  56 EOF
  57 case $HOSTNAME in
  58     treetowl|x2|frodo)
  59         tu /etc/fstab <<EOF
  60 $first_root_crypt  /p  btrfs  noatime,subvol=p  0 0
  61 EOF
  62         ;;
  63 esac
  64 if [[ $HOSTNAME == treetowl ]]; then
  65     # partitioned it with fai partitioner outside of fai,
  66     # because it\'s worth it to have 1% space reserved for boot and
  67     # swap partitions in case I ever want to boot off those drives.
  68     # as root:
  69     # . /a/bin/fai/fai-wrapper
  70     # eval-fai-classfile /a/bin/fai/fai/config/class/51-multi-boot
  71     # fai-setclass ROTATIONAL
  72     # export LUKS_DIR=/q/root/luks/
  73     # # because the partition nums existed already
  74     # fai-setclass REPARTITION
  75     # /a/bin/fai/fai/config/hooks/partition.DEFAULT
  76
  77     # just the first in the btrfs raid
  78     dev=ata-TOSHIBA_MD04ACA500_84REK6NTFS9A-part1
  79     tu /etc/fstab <<EOF
  80 /dev/mapper/crypt_dev_$dev /i btrfs  noatime,subvol=i  0 0
  81 EOF
  82     tu /etc/crypttab <<EOF
  83 crypt_dev_$dev  /dev/disk/by-id/$dev  /q/root/luks/host-treetowl  discard,luks
  84 EOF
  85
  86 else
  87     tu /etc/fstab <<'EOF'
  88 /q/i  /i  none  bind  0 0
  89 EOF
  90
  91 fi
  92
  93 mkdir -p /q /p /i
  94
  95 for vol in q p; do
  96     d=/$vol
  97     if ! awk '{print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
  98         continue
  99     fi
 100
 101
 102     binds=()
 103     roots=($d)
 104     while true; do
 105         new_roots=()
 106         for r in ${roots[@]}; do
 107             # /q/a  /a  none  bind  0 0
 108             new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+bind\s.*#\1#" /etc/fstab))
 109         done
 110         (( ${#new_roots} )) || break
 111         binds+=(${new_roots[@]})
 112         roots=( ${new_roots[@]} )
 113     done
 114
 115     if e check-subvol-stale $d; then
 116         for b in ${binds[@]}; do
 117             mount $b
 118         done
 119         continue
 120     fi
 121
 122     last_snap=$(</nocow/btrfs-stale/$vol)
 123     if [[ ! $last_snap ]]; then
 124         echo "$0: error. empty last_snap var"
 125         ret=1
 126         continue
 127     fi
 128
 129     umount_ret=true
 130     unmounted=()
 131     for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 132         if mountpoint $dir; then
 133             if e umount -R $dir; then
 134                 unmounted+=($dir)
 135             else
 136                 umount_ret=false
 137                 echo "$0: failed to umount $dir"
 138                 break
 139             fi
 140         fi
 141     done
 142
 143     if ! $umount_ret; then
 144         for dir in ${unmounted[@]}; do
 145             mount $dir
 146         done
 147         ret=1
 148         continue
 149     fi
 150
 151     cd /mnt/root
 152     if [[ -e $vol ]]; then
 153         e btrfs sub del $vol
 154     fi
 155     # Note, we make a few assumptions in this script, like
 156     # $d was not a different subvol id than $vol, and
 157     # things otherwise didn't get mounted very strangely.
 158     e btrfs sub snapshot btrbk/$last_snap $vol
 159     for dir in $d ${binds[@]}; do
 160         e mount $dir
 161     done
 162 done
 163 exit $ret