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