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 $1
  35 }
  36
  37
  38 err-bash-trace() {
  39   local -i argc_index=0 frame i start=${1:-0} max_indent=8 indent
  40   local source
  41   local extdebug=false
  42   if [[ $(shopt -p extdebug) == *-s* ]]; then
  43     extdebug=true
  44   fi
  45   for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
  46     argc=${BASH_ARGC[frame]}
  47     argc_index+=$argc
  48     ((frame < start)) && continue
  49     if (( ${#BASH_SOURCE[@]} > 1 )); then
  50       source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
  51     fi
  52     indent=$((frame-start + 1))
  53     indent=$((indent < max_indent ? indent : max_indent))
  54     printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
  55     if $extdebug; then
  56       for ((i=argc_index-1; i >= argc_index-argc; i--)); do
  57         printf " %s" "${BASH_ARGV[i]}"
  58       done
  59     fi
  60     echo \'
  61   done
  62   return 0
  63 }
  64 err-catch() {
  65   set -E; shopt -s extdebug
  66   _err-trap() {
  67     err=$?
  68     exec >&2
  69     set +x
  70     echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}: \`$BASH_COMMAND' returned $err"
  71     err-bash-trace 2
  72     set -e # err trap does not work within an error trap
  73     "${_errcatch_cleanup[@]:-:}" # note :-: is to be compatible with set -u
  74     echo "$0: exiting with code $err"
  75     exit $err
  76   }
  77   trap _err-trap ERR
  78   set -o pipefail
  79 }
  80 err-catch
  81
  82 tu() {
  83   while read -r line; do
  84     file="$1"
  85     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  86   done
  87 }
  88 m() {
  89   if $verbose; then
  90     printf "%s\n" "$*"
  91   fi
  92   "$@"
  93 }
  94 x() {
  95   printf "%s\n" "$*"
  96   "$@"
  97 }
  98
  99 mnt() {
 100   dir=$1
 101   if ! mountpoint -q $dir; then
 102     mkdir -p $dir
 103     m mount $dir
 104   fi
 105 }
 106 fstab() {
 107   while read -r start mpoint end; do
 108     l="$start $mpoint $end"
 109     # kill off any lines that duplicate the mount point.
 110     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
 111     tu /etc/fstab <<<"$l"
 112   done
 113 }
 114 pid-check() {
 115   for p in ${pids}; do
 116     for m in ${my_pids[@]}; do
 117       if (( p == m )); then
 118         echo "$0: error: pids to kill includes our pid or a parent. ps output:" >&2
 119         ps -f -p $p
 120         exit 1
 121       fi
 122     done
 123   done
 124 }
 125 kill-dir() {
 126   for sig; do
 127     echo kill-dir $sig
 128     found_pids=false
 129     if pids=$(timeout 4 lsof -t $dir); then
 130       found_pids=true
 131       timeout 4 lsof -w $dir
 132       pid-check
 133       kill -$sig $pids
 134     fi
 135     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 136     # note: -v shows kernel processes, which then doesn't return true when we want
 137     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 138       pid-check
 139       found_pids=true
 140       fuser -$sig -mvk $dir
 141     fi
 142     sleep .5
 143     if ! $found_pids; then
 144       return 0
 145     fi
 146   done
 147   return 1
 148 }
 149
 150 ##### begin command line parsing ########
 151
 152 # you can remove this if you do not have options which can have args with spaces or empty.
 153
 154 verbose=false
 155 force=false
 156 temp=$(getopt -l help,force,verbose hfv "$@") || usage 1
 157 eval set -- "$temp"
 158 while true; do
 159   case $1 in
 160     -f|--force) force=true ;;
 161     -v|--verbose) verbose=true ;;
 162     -h|--help) usage ;;
 163     --) shift; break ;;
 164     *) echo "$0: unexpected args: $*" >&2 ; usage 1 ;;
 165   esac
 166   shift
 167 done
 168
 169 ##### end command line parsing ########
 170
 171 ret=0
 172
 173 ##### begin setup fstab for subvols we care about ######
 174 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 175 if [[ $root_dev == /dev/dm-* ]]; then
 176   for d in /dev/mapper/*; do
 177     if [[ $(readlink -f $d) == "$root_dev" ]]; then
 178       root_dev=$d
 179       break
 180     fi
 181   done
 182 fi
 183
 184 if cryptsetup status $root_dev &>/dev/null; then
 185   crypt_dev=$root_dev
 186 else # if we are in a recovery boot, find the next best crypt device
 187   noauto=,noauto
 188   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 189     dev=/dev/mapper/$dev
 190     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 191       crypt_dev=$dev
 192       break
 193     fi
 194   done
 195 fi
 196
 197
 198 fstab <<EOF
 199 $crypt_dev  /a  btrfs  noatime,subvol=a$noauto  0 0
 200 EOF
 201
 202 shopt -s nullglob
 203
 204 # ssh and probably some other things care about parent directory
 205 # ownership, and ssh doesn\'t allow any group writable parent
 206 # directories, so we are forced to use a directory structure similar
 207 # to home directories
 208 f=(/mnt/root/btrbk/q.*); f=${f[0]}
 209 if [[ -e $f ]]; then
 210   fstab <<EOF
 211 $crypt_dev  /q  btrfs  noatime,subvol=q,gid=1000$noauto  0 0
 212 /q/p  /p  none  bind$noauto  0 0
 213 EOF
 214 fi
 215
 216 f=(/mnt/root/btrbk/o.*); f=${f[0]}
 217 if [[ -e $f ]]; then
 218   fstab <<EOF
 219 $crypt_dev  /o  btrfs  noatime,subvol=o$noauto  0 0
 220 /o/m  /m  none  bind$noauto  0 0
 221 EOF
 222 fi
 223
 224 if [[ $HOSTNAME == frodo ]]; then
 225   fstab <<EOF
 226 $crypt_dev  /i  btrfs  noatime,subvol=i$noauto  0 0
 227 EOF
 228 fi
 229 ##### end setup fstab for subvols we care about ######
 230
 231 # get pids that this program depends on so we dont kill them
 232 my_pids=($$ $PPID)
 233 loop_limit=30
 234 count=0
 235 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != ${my_pids[-2]} && $count -lt $loop_limit  ]]; do
 236   count=$((count + 1))
 237   p=$(ps -p ${my_pids[-1]} -o ppid=)
 238   if [[ $p == 0 || ! $p ]]; then
 239     break
 240   fi
 241   my_pids+=($p)
 242 done
 243
 244
 245 for vol in q a o i; do
 246   d=/$vol
 247   if ! awk '{print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 248     continue
 249   fi
 250
 251
 252   ##### begin building up list of bind mounts  ######
 253   binds=() # list of bind mounts
 254   roots=($d) # list of bind mounts, plus the original mount
 255   while true; do
 256     new_roots=()
 257     for r in ${roots[@]}; do
 258       # eg. when r=/q/p, for lines like
 259       # /q/p  /p  none  bind  0 0
 260       # output /p
 261       new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+bind\s.*#\1#p" /etc/fstab))
 262     done
 263     (( ${#new_roots} )) || break
 264     binds+=(${new_roots[@]})
 265     roots=( ${new_roots[@]} )
 266   done
 267   ##### end building up list of bind mounts  ######
 268
 269
 270   # if latest is already mounted, make sure binds are mounted and move on
 271   m check-subvol-stale $d
 272   # populated by check-subvol-stale if stale
 273   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 274     mnt $d
 275     for b in ${binds[@]}; do
 276       mnt $b
 277     done
 278     continue
 279   fi
 280
 281   umount_ret=true
 282   unmounted=()
 283   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 284     if mountpoint -q $dir; then
 285       if m umount -R $dir; then
 286         unmounted+=($dir)
 287       else
 288         if ! kill-dir TERM TERM TERM INT INT HUP HUP; then
 289           if $force; then  kill-dir KILL; fi
 290         fi
 291
 292         if m umount -R $dir; then
 293           unmounted+=($dir)
 294         else
 295           echo "$0: failed to umount $dir"
 296           umount_ret=false
 297           ret=1
 298           continue
 299         fi
 300       fi
 301     fi
 302   done
 303
 304   # if we unmounted some but not all, restore them and move on
 305   if ! $umount_ret; then
 306     for dir in ${unmounted[@]}; do
 307       mnt $dir
 308     done
 309     continue
 310   fi
 311
 312   #### begin dealing with leaf vols ####
 313   # todo: decipher /mnt/root, like we do in check-subvol-stale
 314   cd /mnt/root
 315   if [[ -e $vol ]]; then
 316     leaf=$vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 317     m mv $vol $leaf
 318     m btrfs property set -ts $leaf ro true
 319
 320     ### begin check if leaf is different, delete it if not ###
 321     if [[ -e /a/opt/btrfs-snapshots-diff/btrfs-snapshots-diff.py ]]; then
 322       source /a/bin/distro-functions/src/package-manager-abstractions
 323       pi python-jmespath # dependency
 324       parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
 325       bsubs=(/mnt/root/btrbk/$vol.*)
 326       bsub=
 327       # go in reverse order as its more likely to be at the end
 328       for ((i=${#bsubs[@]}-1; i>=0; i--)); do
 329         if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
 330           bsub=${bsubs[i]}
 331           break
 332         fi
 333       done
 334       if [[ $bsub ]]; then
 335         tmp=$(mktemp)
 336         # in testing, same subvol is 136 bytes. allow some overhead
 337         btrfs send --no-data -p $bsub $leaf | head -c 1000 > $tmp || [[ $? == 141 ]]
 338         if (( $(stat -c%s $tmp) < 1000)); then
 339           # example output for an empty diff:
 340           # Found a valid Btrfs stream header, version 1
 341           # o.leaf.2019-05-15T14:00:50-0400;snapshot: uuid=ba045ea30737dd449003f1ee40ec12d0, ctrasid=109533, clone_uuid=3c7e3544e486834aa71d89e5b8f30056, clone_ctransid=109533
 342           lines=$(/a/opt/btrfs-snapshots-diff/btrfs-snapshots-diff.py -s -f $tmp | \
 343                     grep -vxF "Found a valid Btrfs stream header, version 1" | \
 344                     grep -cv "^[^;]*;snapshot: ") ||:
 345           if [[ $lines == 0 ]]; then
 346             x btrfs sub del $leaf
 347           fi
 348         fi
 349       fi
 350     fi
 351     ### end check if leaf is different, delete it if not ###
 352
 353     ## begin expire leaf vols ##
 354     leaf_vols=($vol.leaf.*)
 355     count=1
 356     for leaf in ${leaf_vols[@]}; do
 357       leaf_secs=$(date -d ${leaf#$vol.leaf.} +%s)
 358       if (( $(date +%s) - 60*60*24*60 > leaf_secs || count > 200 )); then # 60 days
 359         x btrfs sub del $leaf
 360       fi
 361       count=$((count+1))
 362     done
 363     ## end expire leaf vols ##
 364   fi
 365   #### end dealing with leaf vols ####
 366
 367   # Note, we make a few assumptions in this script, like
 368   # $d was not a different subvol id than $vol, and
 369   # things otherwise didn't get mounted very strangely.
 370   m btrfs sub snapshot $fresh_snap $vol
 371   for dir in $d ${binds[@]}; do
 372     m mnt $dir
 373   done
 374   stale_dir=/nocow/btrfs-stale
 375   rm -f $stale_dir/$d
 376
 377 done
 378
 379 ### disabled
 380 if [[ $HOSTNAME == kdxxxxxxxxx ]]; then
 381   # partitioned it with fai partitioner outside of fai,
 382   # because it\'s worth it to have 1% space reserved for boot and
 383   # swap partitions in case I ever want to boot off those drives.
 384   # as root:
 385   # . /a/bin/fai/fai-wrapper
 386   # eval-fai-classfile /a/bin/fai/fai/config/class/51-multi-boot
 387   # fai-setclass ROTATIONAL
 388   # export LUKS_DIR=/q/root/luks/
 389   # # because the partition nums existed already
 390   # fai-setclass REPARTITION
 391   # /a/bin/fai/fai/config/hooks/partition.DEFAULT
 392
 393   devs=(
 394     ata-TOSHIBA_MD04ACA500_84REK6NTFS9A-part1
 395     ata-TOSHIBA_MD04ACA500_84R2K773FS9A-part1
 396     ata-TOSHIBA_MD04ACA500_8471K430FS9A-part1
 397     ata-TOSHIBA_MD04ACA500_8481K493FS9A-part1
 398   )
 399   first=true
 400   for dev in ${devs[@]}; do
 401     if $first; then
 402       first=false
 403       tu /etc/fstab <<EOF
 404 /dev/mapper/crypt_dev_$dev /i btrfs  noatime,subvol=i,noauto  0 0
 405 /dev/mapper/crypt_dev_$dev /mnt/iroot btrfs  noatime,subvolid=0,noauto  0 0
 406 EOF
 407     fi
 408     tu /etc/crypttab <<EOF
 409 crypt_dev_$dev  /dev/disk/by-id/$dev  /q/root/luks/host-kd  discard,luks
 410 EOF
 411     if [[ ! -e /dev/mapper/crypt_dev_$dev ]]; then
 412       cryptdisks_start crypt_dev_$dev
 413     fi
 414   done
 415   # note, could do an else here and have some kind of mount for /i
 416   # on other hosts.
 417 fi
 418
 419 exit $ret