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 script=$(readlink -f -- "$BASH_SOURCE")
  17 cd /
  18 [[ $EUID == 0 ]] || exec sudo -E "$script" "$@"
  19
  20
  21 usage() {
  22   cat <<EOF
  23 Usage: ${0##*/} [OPTIONS]
  24
  25 -h|--help  Print help and exit.
  26
  27
  28 Note, at source location, intentionally not executable, run and read
  29 install-my-scripts.
  30
  31 Note: Uses util-linux getopt option parsing: spaces between args and
  32 options, short options can be combined, options before args.
  33 EOF
  34   exit $1
  35 }
  36
  37
  38 errcatch() {
  39   set -E; shopt -s extdebug
  40   _err-trap() {
  41     err=$?
  42     exec >&2
  43     set +x
  44     echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}:in \`$BASH_COMMAND' returned $err"
  45     bash-trace 2
  46     echo "$0: exiting with code $err"
  47     exit $err
  48   }
  49   trap _err-trap ERR
  50   set -o pipefail
  51 }
  52 bash-trace() {
  53   local -i argc_index=0 frame i start=${1:-1} max_indent=8 indent
  54   local source
  55   local extdebug=false
  56   if [[ $(shopt -p extdebug) == *-s* ]]; then
  57     extdebug=true
  58   fi
  59
  60   for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
  61     argc=${BASH_ARGC[frame]}
  62     argc_index+=$argc
  63     ((frame < start)) && continue
  64     if (( ${#BASH_SOURCE[@]} > 1 )); then
  65       source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
  66     fi
  67     indent=$((frame-start+1))
  68     indent=$((indent < max_indent ? indent : max_indent))
  69     printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
  70     if $extdebug; then
  71       for ((i=argc_index-1; i >= argc_index-argc; i--)); do
  72         printf " %s" "${BASH_ARGV[i]}"
  73       done
  74     fi
  75     echo \'
  76   done
  77 }
  78 errcatch
  79
  80 tu() {
  81   while read -r line; do
  82     file="$1"
  83     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  84   done
  85 }
  86 m() {
  87   if $verbose; then
  88     printf "%s\n" "$*"
  89   fi
  90   "$@"
  91 }
  92 x() {
  93   printf "%s\n" "$*"
  94   "$@"
  95 }
  96
  97 mnt() {
  98   dir=$1
  99   if ! mountpoint -q $dir; then
 100     mkdir -p $dir
 101     m mount $dir
 102   fi
 103 }
 104 fstab() {
 105   while read -r start mpoint end; do
 106     l="$start $mpoint $end"
 107     # kill off any lines that duplicate the mount point.
 108     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
 109     tu /etc/fstab <<<"$l"
 110   done
 111 }
 112 pid-check() {
 113   for p in ${pids}; do
 114     for m in ${my_pids[@]}; do
 115       if (( p == m )); then
 116         echo "$0: error: pids to kill includes our pid or a parent. ps output:" >&2
 117         ps -f -p $p
 118         exit 1
 119       fi
 120     done
 121   done
 122 }
 123 kill-dir() {
 124   for sig; do
 125     echo kill-dir $sig
 126     found_pids=false
 127     if pids=$(timeout 4 lsof -t $dir); then
 128       found_pids=true
 129       timeout 4 lsof -w $dir
 130       pid-check
 131       kill -$sig $pids
 132     fi
 133     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 134     # note: -v shows kernel processes, which then doesn't return true when we want
 135     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 136       pid-check
 137       found_pids=true
 138       fuser -$sig -mvk $dir
 139     fi
 140     sleep .5
 141     if ! $found_pids; then
 142       return 0
 143     fi
 144   done
 145   return 1
 146 }
 147
 148 ##### begin command line parsing ########
 149
 150 # you can remove this if you do not have options which can have args with spaces or empty.
 151
 152 verbose=false
 153 force=false
 154 temp=$(getopt -l help,force,verbose hfv "$@") || usage 1
 155 eval set -- "$temp"
 156 while true; do
 157   case $1 in
 158     -f|--force) force=true ;;
 159     -v|--verbose) verbose=true ;;
 160     -h|--help) usage ;;
 161     --) shift; break ;;
 162     *) echo "$0: unexpected args: $*" >&2 ; usage 1 ;;
 163   esac
 164   shift
 165 done
 166
 167 ##### end command line parsing ########
 168
 169 ret=0
 170
 171 ##### begin setup fstab for subvols we care about ######
 172 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 173 if [[ $root_dev == /dev/dm-* ]]; then
 174   for d in /dev/mapper/*; do
 175     if [[ $(readlink -f $d) == "$root_dev" ]]; then
 176       root_dev=$d
 177       break
 178     fi
 179   done
 180 fi
 181
 182 if cryptsetup status $root_dev &>/dev/null; then
 183   crypt_dev=$root_dev
 184 else # if we are in a recovery boot, find the next best crypt device
 185   noauto=,noauto
 186   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 187     dev=/dev/mapper/$dev
 188     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 189       crypt_dev=$dev
 190       break
 191     fi
 192   done
 193 fi
 194
 195
 196 fstab <<EOF
 197 $crypt_dev  /a  btrfs  noatime,subvol=a$noauto  0 0
 198 EOF
 199
 200 shopt -s nullglob
 201
 202 # ssh and probably some other things care about parent directory
 203 # ownership, and ssh doesn\'t allow any group writable parent
 204 # directories, so we are forced to use a directory structure similar
 205 # to home directories
 206 f=(/mnt/root/btrbk/q.*); f=${f[0]}
 207 if [[ -e $f ]]; then
 208   fstab <<EOF
 209 $crypt_dev  /q  btrfs  noatime,subvol=q,gid=1000$noauto  0 0
 210 /q/p  /p  none  bind$noauto  0 0
 211 EOF
 212 fi
 213
 214 f=(/mnt/root/btrbk/o.*); f=${f[0]}
 215 if [[ -e $f ]]; then
 216   fstab <<EOF
 217 $crypt_dev  /o  btrfs  noatime,subvol=o$noauto  0 0
 218 /o/m  /m  none  bind$noauto  0 0
 219 EOF
 220 fi
 221
 222 if [[ $HOSTNAME == frodo ]]; then
 223   fstab <<EOF
 224 $crypt_dev  /i  btrfs  noatime,subvol=i$noauto  0 0
 225 EOF
 226 fi
 227 ##### end setup fstab for subvols we care about ######
 228
 229 # get pids that this program depends on so we dont kill them
 230 my_pids=($$ $PPID)
 231 loop_limit=30
 232 count=0
 233 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != ${my_pids[-2]} && $count -lt $loop_limit  ]]; do
 234   count=$((count + 1))
 235   p=$(ps -p ${my_pids[-1]} -o ppid=)
 236   if [[ $p == 0 || ! $p ]]; then
 237     break
 238   fi
 239   my_pids+=($p)
 240 done
 241
 242
 243 for vol in q a o i; do
 244   d=/$vol
 245   if ! awk '{print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 246     continue
 247   fi
 248
 249
 250   ##### begin building up list of bind mounts  ######
 251   binds=() # list of bind mounts
 252   roots=($d) # list of bind mounts, plus the original mount
 253   while true; do
 254     new_roots=()
 255     for r in ${roots[@]}; do
 256       # eg. when r=/q/p, for lines like
 257       # /q/p  /p  none  bind  0 0
 258       # output /p
 259       new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+bind\s.*#\1#p" /etc/fstab))
 260     done
 261     (( ${#new_roots} )) || break
 262     binds+=(${new_roots[@]})
 263     roots=( ${new_roots[@]} )
 264   done
 265   ##### end building up list of bind mounts  ######
 266
 267
 268   # if latest is already mounted, make sure binds are mounted and move on
 269   m check-subvol-stale $d
 270   # populated by check-subvol-stale if stale
 271   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 272     mnt $d
 273     for b in ${binds[@]}; do
 274       mnt $b
 275     done
 276     continue
 277   fi
 278
 279   umount_ret=true
 280   unmounted=()
 281   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 282     if mountpoint -q $dir; then
 283       if m umount -R $dir; then
 284         unmounted+=($dir)
 285       else
 286         if ! kill-dir TERM TERM TERM INT INT HUP HUP; then
 287           if $force; then  kill-dir KILL; fi
 288         fi
 289
 290         if m umount -R $dir; then
 291           unmounted+=($dir)
 292         else
 293           echo "$0: failed to umount $dir"
 294           umount_ret=false
 295           ret=1
 296           continue
 297         fi
 298       fi
 299     fi
 300   done
 301
 302   # if we unmounted some but not all, restore them and move on
 303   if ! $umount_ret; then
 304     for dir in ${unmounted[@]}; do
 305       mnt $dir
 306     done
 307     continue
 308   fi
 309
 310   #### begin dealing with leaf vols ####
 311   # todo: decipher /mnt/root, like we do in check-subvol-stale
 312   cd /mnt/root
 313   if [[ -e $vol ]]; then
 314     leaf=$vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 315     m mv $vol $leaf
 316     m btrfs property set -ts $leaf ro true
 317
 318     ### begin check if leaf is different, delete it if not ###
 319     if [[ -e /a/opt/btrfs-snapshots-diff/btrfs-snapshots-diff.py ]]; then
 320       source /a/bin/distro-functions/src/package-manager-abstractions
 321       pi python-jmespath # dependency
 322       parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
 323       bsubs=(/mnt/root/btrbk/$vol.*)
 324       bsub=
 325       # go in reverse order as its more likely to be at the end
 326       for ((i=${#bsubs[@]}-1; i>=0; i--)); do
 327         if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
 328           bsub=${bsubs[i]}
 329           break
 330         fi
 331       done
 332       if [[ $bsub ]]; then
 333         tmp=$(mktemp)
 334         # in testing, same subvol is 136 bytes. allow some overhead
 335         btrfs send --no-data -p $bsub $leaf | head -c 1000 > $tmp || [[ $? == 141 ]]
 336         if (( $(stat -c%s $tmp) < 1000)); then
 337           # example output for an empty diff:
 338           # Found a valid Btrfs stream header, version 1
 339           # o.leaf.2019-05-15T14:00:50-0400;snapshot: uuid=ba045ea30737dd449003f1ee40ec12d0, ctrasid=109533, clone_uuid=3c7e3544e486834aa71d89e5b8f30056, clone_ctransid=109533
 340           lines=$(/a/opt/btrfs-snapshots-diff/btrfs-snapshots-diff.py -s -f $tmp | \
 341                     grep -vxF "Found a valid Btrfs stream header, version 1" | \
 342                     grep -cv "^[^;]*;snapshot: ") ||:
 343           if [[ $lines == 0 ]]; then
 344             x btrfs sub del $leaf
 345           fi
 346         fi
 347       fi
 348     fi
 349     ### end check if leaf is different, delete it if not ###
 350
 351     ## begin expire leaf vols ##
 352     leaf_vols=($vol.leaf.*)
 353     count=1
 354     for leaf in ${leaf_vols[@]}; do
 355       leaf_secs=$(date -d ${leaf#$vol.leaf.} +%s)
 356       if (( $(date +%s) - 60*60*24*60 > leaf_secs || count > 200 )); then # 60 days
 357         x btrfs sub del $leaf
 358       fi
 359       count=$((count+1))
 360     done
 361     ## end expire leaf vols ##
 362   fi
 363   #### end dealing with leaf vols ####
 364
 365   # Note, we make a few assumptions in this script, like
 366   # $d was not a different subvol id than $vol, and
 367   # things otherwise didn't get mounted very strangely.
 368   m btrfs sub snapshot $fresh_snap $vol
 369   for dir in $d ${binds[@]}; do
 370     m mnt $dir
 371   done
 372   stale_dir=/nocow/btrfs-stale
 373   rm -f $stale_dir/$d
 374
 375 done
 376
 377 ### disabled
 378 if [[ $HOSTNAME == kdxxxxxxxxx ]]; then
 379   # partitioned it with fai partitioner outside of fai,
 380   # because it\'s worth it to have 1% space reserved for boot and
 381   # swap partitions in case I ever want to boot off those drives.
 382   # as root:
 383   # . /a/bin/fai/fai-wrapper
 384   # eval-fai-classfile /a/bin/fai/fai/config/class/51-multi-boot
 385   # fai-setclass ROTATIONAL
 386   # export LUKS_DIR=/q/root/luks/
 387   # # because the partition nums existed already
 388   # fai-setclass REPARTITION
 389   # /a/bin/fai/fai/config/hooks/partition.DEFAULT
 390
 391   devs=(
 392     ata-TOSHIBA_MD04ACA500_84REK6NTFS9A-part1
 393     ata-TOSHIBA_MD04ACA500_84R2K773FS9A-part1
 394     ata-TOSHIBA_MD04ACA500_8471K430FS9A-part1
 395     ata-TOSHIBA_MD04ACA500_8481K493FS9A-part1
 396   )
 397   first=true
 398   for dev in ${devs[@]}; do
 399     if $first; then
 400       first=false
 401       tu /etc/fstab <<EOF
 402 /dev/mapper/crypt_dev_$dev /i btrfs  noatime,subvol=i,noauto  0 0
 403 /dev/mapper/crypt_dev_$dev /mnt/iroot btrfs  noatime,subvolid=0,noauto  0 0
 404 EOF
 405     fi
 406     tu /etc/crypttab <<EOF
 407 crypt_dev_$dev  /dev/disk/by-id/$dev  /q/root/luks/host-kd  discard,luks
 408 EOF
 409     if [[ ! -e /dev/mapper/crypt_dev_$dev ]]; then
 410       cryptdisks_start crypt_dev_$dev
 411     fi
 412   done
 413   # note, could do an else here and have some kind of mount for /i
 414   # on other hosts.
 415 fi
 416
 417 exit $ret