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

   1 #!/bin/bash
   2 # Copyright (C) 2016 Ian Kelling
   3 #
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at
   7 #
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9 #
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16 # usage: mount-latest-subvol
  17
  18 cd /
  19 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
  20
  21 errcatch() {
  22   set -E; shopt -s extdebug
  23   _err-trap() {
  24     err=$?
  25     exec >&2
  26     set +x
  27     echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}:in \`$BASH_COMMAND' returned $err"
  28     bash-trace 2
  29     echo "$0: exiting with code $err"
  30     exit $err
  31   }
  32   trap _err-trap ERR
  33   set -o pipefail
  34 }
  35 bash-trace() {
  36   local -i argc_index=0 frame i start=${1:-1} max_indent=8 indent
  37   local source
  38   local extdebug=false
  39   if [[ $(shopt -p extdebug) == *-s* ]]; then
  40     extdebug=true
  41   fi
  42
  43   for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
  44     argc=${BASH_ARGC[frame]}
  45     argc_index+=$argc
  46     ((frame < start)) && continue
  47     if (( ${#BASH_SOURCE[@]} > 1 )); then
  48       source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
  49     fi
  50     indent=$((frame-start+1))
  51     indent=$((indent < max_indent ? indent : max_indent))
  52     printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
  53     if $extdebug; then
  54       for ((i=argc_index-1; i >= argc_index-argc; i--)); do
  55         printf " %s" "${BASH_ARGV[i]}"
  56       done
  57     fi
  58     echo \'
  59   done
  60 }
  61 errcatch
  62
  63 tu() {
  64   while read -r line; do
  65     file="$1"
  66     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  67   done
  68 }
  69 e() { printf "%s\n" "$*"; "$@"; }
  70 mnt() {
  71   dir=$1
  72   if ! mountpoint $dir &>/dev/null; then
  73     mkdir -p $dir
  74     e mount $dir
  75   fi
  76 }
  77 fstab() {
  78   while read -r start mpoint end; do
  79     l="$start $mpoint $end"
  80     # kill off any lines that duplicate the mount point.
  81     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
  82     tu /etc/fstab <<<"$l"
  83   done
  84 }
  85 pid-check() {
  86   for p in ${pids}; do
  87     for m in ${my_pids[@]}; do
  88       if (( p == m )); then
  89         echo "$0: error: pids to kill includes our pid or a parent" >&2
  90         ps -f -p $p
  91         exit 1
  92       fi
  93     done
  94   done
  95 }
  96 kill-dir() {
  97   for sig; do
  98     echo kill-dir $sig
  99     found_pids=false
 100     if pids=$(timeout 4 lsof -t $dir); then
 101       found_pids=true
 102       timeout 4 lsof -w $dir
 103       pid-check
 104       kill -$sig $pids
 105     fi
 106     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 107     # note: -v shows kernel processes, which then doesn't return true when we want
 108     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 109       pid-check
 110       found_pids=true
 111       fuser -$sig -mvk $dir
 112     fi
 113     sleep .5
 114     if ! $found_pids; then
 115       return 0
 116     fi
 117   done
 118   return 1
 119 }
 120
 121 force=false
 122 if [[ $1 == -f ]]; then
 123   force=true
 124 fi
 125
 126 ret=0
 127
 128 ##### begin setup fstab for subvols we care about ######
 129 first_root_crypt=$(awk '$2 == "/" {print $1}' /etc/mtab)
 130 fstab <<EOF
 131 $first_root_crypt  /a  btrfs  noatime,subvol=a  0 0
 132 EOF
 133
 134 shopt -s nullglob
 135
 136 # ssh and probably some other things care about parent directory
 137 # ownership, and ssh doesn\'t allow any group writable parent
 138 # directories, so we are forced to use a directory structure similar
 139 # to home directories
 140 f=(/mnt/root/btrbk/q.*)
 141 if [[ -e $f ]]; then
 142   fstab <<EOF
 143 $first_root_crypt  /q  btrfs  noatime,subvol=q,gid=1000  0 0
 144 /q/p  /p  none  bind  0 0
 145 EOF
 146 fi
 147
 148 f=(/mnt/root/btrbk/o.*)
 149 if [[ -e $f ]]; then
 150   fstab <<EOF
 151 $first_root_crypt  /o  btrfs  noatime,subvol=o  0 0
 152 /o/m  /m  none  bind  0 0
 153 EOF
 154 fi
 155
 156 if [[ $HOSTNAME == frodo ]]; then
 157   fstab <<EOF
 158 $first_root_crypt  /i  btrfs  noatime,subvol=i  0 0
 159 EOF
 160 fi
 161 ##### end setup fstab for subvols we care about ######
 162
 163 # get pids that this program depends on so we dont kill them
 164 my_pids=($$ $PPID)
 165 loop_limit=30
 166 count=0
 167 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != ${my_pids[-2]} && $count -lt $loop_limit  ]]; do
 168   count=$((count + 1))
 169   p=$(ps -p ${my_pids[-1]} -o ppid=)
 170   if [[ $p == 0 || ! $p ]]; then
 171     break
 172   fi
 173   my_pids+=($p)
 174 done
 175
 176
 177 for vol in q a o i; do
 178   d=/$vol
 179   if ! awk '{print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 180     continue
 181   fi
 182
 183
 184   ##### begin building up list of bind mounts  ######
 185   binds=() # list of bind mounts
 186   roots=($d) # list of bind mounts, plus the original mount
 187   while true; do
 188     new_roots=()
 189     for r in ${roots[@]}; do
 190       # eg. when r=/q/p, for lines like
 191       # /q/p  /p  none  bind  0 0
 192       # output /p
 193       new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+bind\s.*#\1#p" /etc/fstab))
 194     done
 195     (( ${#new_roots} )) || break
 196     binds+=(${new_roots[@]})
 197     roots=( ${new_roots[@]} )
 198   done
 199   ##### end building up list of bind mounts  ######
 200
 201
 202   # if latest is already mounted, make sure binds are mounted and move on
 203   if e check-subvol-stale $d; then
 204     mnt $d
 205     for b in ${binds[@]}; do
 206       mnt $b
 207     done
 208     continue
 209   fi
 210
 211   fresh_snap=$(</nocow/btrfs-stale/$vol)
 212   if [[ ! $fresh_snap ]]; then
 213     echo "$0: error. empty fresh_snap var"
 214     ret=1
 215     continue
 216   fi
 217
 218   umount_ret=true
 219   unmounted=()
 220   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 221     if mountpoint $dir; then
 222       if e umount -R $dir; then
 223         unmounted+=($dir)
 224       else
 225         if ! kill-dir TERM TERM TERM INT INT HUP HUP; then
 226           if $force; then  kill-dir KILL; fi
 227         fi
 228
 229         if e umount -R $dir; then
 230           unmounted+=($dir)
 231         else
 232           echo "$0: failed to umount $dir"
 233           umount_ret=false
 234           ret=1
 235           continue
 236         fi
 237       fi
 238     fi
 239   done
 240
 241   if ! $umount_ret; then
 242     for dir in ${unmounted[@]}; do
 243       mnt $dir
 244     done
 245     continue
 246   fi
 247
 248   # todo: decipher /mnt/root, like we do in check-subvol-stale
 249   cd /mnt/root
 250   if [[ -e $vol ]]; then
 251     e mv $vol $vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 252     leaf_vols=($vol.leaf.*)
 253     for leaf in ${leaf_vols[@]}; do
 254       leaf_secs=$(date -d ${leaf#$vol.leaf.} +%s)
 255       if (( $(date +%s) - 60*60*24*60 > leaf_secs )); then # 60 days
 256         e btrfs sub del $leaf
 257       fi
 258     done
 259   fi
 260   # Note, we make a few assumptions in this script, like
 261   # $d was not a different subvol id than $vol, and
 262   # things otherwise didn't get mounted very strangely.
 263   e btrfs sub snapshot $fresh_snap $vol
 264   for dir in $d ${binds[@]}; do
 265     e mnt $dir
 266   done
 267   stale_dir=/nocow/btrfs-stale
 268   rm -f $stale_dir/$d
 269 done
 270
 271 ### disabled
 272 if [[ $HOSTNAME == kdxxxxxxxxx ]]; then
 273   # partitioned it with fai partitioner outside of fai,
 274   # because it\'s worth it to have 1% space reserved for boot and
 275   # swap partitions in case I ever want to boot off those drives.
 276   # as root:
 277   # . /a/bin/fai/fai-wrapper
 278   # eval-fai-classfile /a/bin/fai/fai/config/class/51-multi-boot
 279   # fai-setclass ROTATIONAL
 280   # export LUKS_DIR=/q/root/luks/
 281   # # because the partition nums existed already
 282   # fai-setclass REPARTITION
 283   # /a/bin/fai/fai/config/hooks/partition.DEFAULT
 284
 285   devs=(
 286     ata-TOSHIBA_MD04ACA500_84REK6NTFS9A-part1
 287     ata-TOSHIBA_MD04ACA500_84R2K773FS9A-part1
 288     ata-TOSHIBA_MD04ACA500_8471K430FS9A-part1
 289     ata-TOSHIBA_MD04ACA500_8481K493FS9A-part1
 290   )
 291   first=true
 292   for dev in ${devs[@]}; do
 293     if $first; then
 294       first=false
 295       tu /etc/fstab <<EOF
 296 /dev/mapper/crypt_dev_$dev /i btrfs  noatime,subvol=i,noauto  0 0
 297 /dev/mapper/crypt_dev_$dev /mnt/iroot btrfs  noatime,subvolid=0,noauto  0 0
 298 EOF
 299     fi
 300     tu /etc/crypttab <<EOF
 301 crypt_dev_$dev  /dev/disk/by-id/$dev  /q/root/luks/host-kd  discard,luks
 302 EOF
 303     if [[ ! -e /dev/mapper/crypt_dev_$dev ]]; then
 304       cryptdisks_start crypt_dev_$dev
 305     fi
 306   done
 307   # note, could do an else here and have some kind of mount for /i
 308   # on other hosts.
 309 fi
 310
 311 exit $ret