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 -f|--force  Use kill -9 to try fixing unmount errors
  28 -v|--verbose  Be more verbose
  29
  30
  31 Note, at source location, intentionally not executable, run and read
  32 install-my-scripts.
  33
  34 Note: Uses util-linux getopt option parsing: spaces between args and
  35 options, short options can be combined, options before args.
  36 EOF
  37   exit $1
  38 }
  39
  40
  41 tu() {
  42   while read -r line; do
  43     file="$1"
  44     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  45   done
  46 }
  47 d() {
  48   if $verbose; then
  49     printf "%s\n" "$*"
  50   fi
  51 }
  52 m() {
  53   if $verbose; then
  54     printf "%s\n" "$*"
  55   fi
  56   "$@"
  57 }
  58 x() {
  59   printf "%s\n" "$*"
  60   "$@"
  61 }
  62
  63 mnt() {
  64   dir=$1
  65   if ! mountpoint -q $dir; then
  66     mkdir -p $dir
  67     m mount $dir
  68   fi
  69 }
  70 fstab() {
  71   while read -r start mpoint end; do
  72     l="$start $mpoint $end"
  73     # kill off any lines that duplicate the mount point.
  74     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
  75     tu /etc/fstab <<<"$l"
  76   done
  77 }
  78 pid-check() {
  79   for p in ${pids}; do
  80     for m in ${my_pids[@]}; do
  81       if (( p == m )); then
  82         echo "$0: error: pids to kill includes our pid or a parent. ps output:" >&2
  83         ps -f -p $p
  84         exit 1
  85       fi
  86     done
  87   done
  88 }
  89 kill-dir() {
  90   for sig; do
  91     echo kill-dir $sig
  92     found_pids=false
  93     if pids=$(timeout 4 lsof -t $dir); then
  94       found_pids=true
  95       timeout 4 lsof -w $dir
  96       pid-check
  97       kill -$sig $pids
  98     fi
  99     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 100     # note: -v shows kernel processes, which then doesn't return true when we want
 101     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 102       pid-check
 103       found_pids=true
 104       fuser -$sig -mvk $dir
 105     fi
 106     sleep .5
 107     if ! $found_pids; then
 108       return 0
 109     fi
 110   done
 111   return 1
 112 }
 113 umount-kill() {
 114   dir=$1
 115   if mountpoint -q $dir; then
 116     if m umount -R $dir; then
 117       unmounted+=($dir)
 118     else
 119       if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 120         if $force; then  kill-dir KILL; fi
 121       fi
 122
 123       if m umount -R $dir; then
 124         unmounted+=($dir)
 125       else
 126         echo "$0: failed to umount $dir"
 127         umount_ret=false
 128         ret=1
 129       fi
 130     fi
 131   fi
 132 }
 133
 134 # duplicated in check-subvol
 135 mapper-dev() {
 136   local mapdev
 137   local -n devref=$1
 138   if [[ $devref == /dev/dm-* ]]; then
 139     for mapdev in /dev/mapper/*; do
 140       if [[ $(readlink -f $mapdev) == "$devref" ]]; then
 141         devref=$mapdev
 142         break
 143       fi
 144     done
 145   fi
 146 }
 147
 148
 149 ##### begin command line parsing ########
 150
 151 # you can remove this if you do not have options which can have args with spaces or empty.
 152
 153 verbose=true
 154 force=false
 155 temp=$(getopt -l help,force,verbose hfv "$@") || usage 1
 156 eval set -- "$temp"
 157 while true; do
 158   case $1 in
 159     -f|--force) force=true ;;
 160     -v|--verbose) verbose=true ;;
 161     -h|--help) usage ;;
 162     --) shift; break ;;
 163     *) echo "$0: unexpected args: $*" >&2 ; usage 1 ;;
 164   esac
 165   shift
 166 done
 167
 168 ##### end command line parsing ########
 169
 170 ret=0
 171
 172 ##### begin setup fstab for subvols we care about ######
 173
 174 if [[ -e /mnt/root/root2-crypttab ]]; then
 175   tu /etc/crypttab </mnt/root/root2-crypttab
 176   while read -r mapper_dev _; do
 177     if [[ ! -e /dev/mapper/$mapper_dev ]]; then
 178       m cryptdisks_start $mapper_dev
 179     fi
 180   done < <(cat /mnt/root/root2-crypttab)
 181 fi
 182 if [[ -e /mnt/root/root2-fstab ]]; then
 183   tu /etc/fstab </mnt/root/root2-fstab
 184   mnt /mnt/root2
 185   mnt /mnt/boot2
 186 fi
 187
 188 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 189 mapper-dev root_dev
 190
 191 # root2_dev=$(awk '$2 == "/mnt/root2" {print $1}' /etc/mtab)
 192 # mapper-dev root2_dev
 193 # # dont bother with the above for crypt2_dev
 194 # crypt2_dev=$root2_dev
 195
 196
 197 if cryptsetup status $root_dev &>/dev/null; then
 198   crypt_dev=$root_dev
 199 else # if we are in a recovery boot, find the next best crypt device
 200   mopts=,noauto
 201   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 202     dev=/dev/mapper/$dev
 203     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 204       crypt_dev=$dev
 205       break
 206     fi
 207   done
 208 fi
 209
 210
 211
 212 # dont tax the cpus of old laptops
 213 if ((`nproc` > 2)); then
 214   mopts+=,compress=zstd
 215 fi
 216
 217 fstab <<EOF
 218 $crypt_dev  /a  btrfs  noatime,subvol=a$mopts  0 0
 219 EOF
 220
 221 shopt -s nullglob
 222
 223 # ssh and probably some other things care about parent directory
 224 # ownership, and ssh doesn\'t allow any group writable parent
 225 # directories, so we are forced to use a directory structure similar
 226 # to home directories
 227 f=(/mnt/root/btrbk/q.*); f=${f[0]}
 228 if [[ -e $f ]]; then
 229   fstab <<EOF
 230 $crypt_dev  /q  btrfs  noatime,subvol=q,gid=1000$mopts  0 0
 231 /q/p  /p  none  bind$mopts  0 0
 232 EOF
 233 fi
 234
 235 f=(/mnt/root/btrbk/o.*); f=${f[0]}
 236 if [[ -e $f ]]; then
 237   fstab <<EOF
 238 $crypt_dev  /o  btrfs  noatime,subvol=o$mopts  0 0
 239 /o/m  /m  none  bind$mopts  0 0
 240 EOF
 241 fi
 242
 243 if [[ $HOSTNAME == frodo ]]; then
 244   fstab <<EOF
 245 $crypt_dev  /i  btrfs  noatime,subvol=i$mopts  0 0
 246 EOF
 247 fi
 248
 249
 250
 251 ##### end setup fstab for subvols we care about ######
 252
 253 ### begin get pids that this program depends on so we dont kill them
 254 my_pids=($$ $PPID)
 255 loop_limit=30
 256 count=0
 257 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != ${my_pids[-2]} && $count -lt $loop_limit  ]]; do
 258   count=$((count + 1))
 259   p=$(ps -p ${my_pids[-1]} -o ppid=)
 260   if [[ $p == 0 || ! $p ]]; then
 261     break
 262   fi
 263   my_pids+=($p)
 264 done
 265 ### end get pids that this program depends on so we dont kill them
 266
 267 for vol in q a o i; do
 268   d=/$vol
 269   if ! awk '{print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 270     continue
 271   fi
 272
 273
 274   ##### begin building up list of bind mounts  ######
 275   binds=() # list of bind mounts
 276   roots=($d)
 277   while true; do
 278     new_roots=()
 279     for r in ${roots[@]}; do
 280       # eg. when r=/q/p, for lines like
 281       # /q/p  /p  none  bind  0 0
 282       # output /p
 283       new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+(\S+,|)bind[[:space:],].*#\1#p" /etc/fstab))
 284     done
 285     (( ${#new_roots} )) || break
 286     binds+=(${new_roots[@]})
 287     # roots is used to recursively find binds of binds if they exist.
 288     roots=( ${new_roots[@]} )
 289   done
 290   ##### end building up list of bind mounts  ######
 291
 292
 293   # if latest is already mounted, make sure binds are mounted and move on
 294   m check-subvol-stale $d
 295   # populated by check-subvol-stale if stale
 296   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 297     mnt $d
 298     did=$(stat -c%d $d)
 299     for b in ${binds[@]}; do
 300       if mountpoint -q $b; then
 301         bid=$(stat -c%d $b)
 302         if [[ $did != $bid ]]; then
 303           umount-kill $b
 304         fi
 305       fi
 306       mnt $b
 307     done
 308     continue
 309   fi
 310
 311   if [[ $vol == q ]]; then
 312     # allow to fail, user might not be logged in
 313     x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user stop arbtt ||:
 314   fi
 315   umount_ret=true
 316   unmounted=()
 317   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 318     umount-kill $dir
 319   done
 320
 321   # if we unmounted some but not all, restore them and move on
 322   if ! $umount_ret; then
 323     for dir in ${unmounted[@]}; do
 324       mnt $dir
 325     done
 326     continue
 327   fi
 328
 329   #### begin dealing with leaf vols ####
 330
 331   ### begin getting root_dir
 332   ### this is duplicated in check-subvol-stale
 333
 334   dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab /etc/mtab|head -n1)
 335   d dev=$dev
 336   # note, we need $dev because $d might not be mounted, and we do this loop
 337   # because the device in fstab for the rootfs can be different.
 338   for devx in $(btrfs fil show $dev| sed -rn 's#.*path (\S+)$#\1#p'); do
 339     if [[ $devx == dm-* ]]; then
 340       devx=/dev/$devx
 341       mapper-dev devx
 342     fi
 343     d devx=$devx
 344     root_dir=$(sed -rn "s,^\s*$devx\s+(\S+).*\bsubvolid=[05]\b.*,\1,p" /etc/mtab /etc/fstab|head -n1)
 345     if [[ $root_dir ]]; then
 346       d root_dir=$root_dir
 347       break
 348     fi
 349   done
 350   if [[ ! $root_dir ]]; then
 351     echo "$0: error could not find root subvol mount for $dev" >&2
 352     exit 1
 353   fi
 354   ### end getting root_dir
 355
 356   cd $root_dir
 357   if [[ -e $vol ]]; then
 358     leaf=$vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 359     m mv $vol $leaf
 360     m btrfs property set -ts $leaf ro true
 361
 362     ### begin check if leaf is different, delete it if not ###
 363     if [[ -e /a/opt/btrfs-snapshots-diff/btrfs-snapshots-diff.py ]]; then
 364       source /a/bin/distro-functions/src/package-manager-abstractions
 365       #pi python-jmespath # dependency of btrfs-snapshots-diff
 366       # todo: need python3 port of btrfs-snapshots-diff, py2 no exist on nabia
 367       parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
 368       bsubs=(/mnt/root/btrbk/$vol.*)
 369       bsub=
 370       # go in reverse order as its more likely to be at the end
 371       for ((i=${#bsubs[@]}-1; i>=0; i--)); do
 372         if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
 373           bsub=${bsubs[i]}
 374           break
 375         fi
 376       done
 377       if [[ $bsub ]]; then
 378         tmp=$(mktemp)
 379         # in testing, same subvol is 136 bytes. allow some overhead. 32 happens sometimes under systemd.
 380         # $ errno 32
 381         # EPIPE 32 Broken pipe
 382         btrfs send --no-data -p $bsub $leaf | head -c 1000 > $tmp || [[ $? == 141 || ${PIPESTATUS[0]} == 32 ]]
 383         if (( $(stat -c%s $tmp) < 1000)); then
 384           # example output for an empty diff:
 385           # Found a valid Btrfs stream header, version 1
 386           # o.leaf.2019-05-15T14:00:50-0400;snapshot: uuid=ba045ea30737dd449003f1ee40ec12d0, ctrasid=109533, clone_uuid=3c7e3544e486834aa71d89e5b8f30056, clone_ctransid=109533
 387           lines=$(/a/opt/btrfs-snapshots-diff/btrfs-snapshots-diff.py -s -f $tmp | \
 388                     grep -vxF "Found a valid Btrfs stream header, version 1" | \
 389                     grep -cv "^[^;]*;snapshot: ") ||:
 390           if [[ $lines == 0 ]]; then
 391             # rotate in case we find a bug, weve got 2 old ones
 392             tmpleaf=($vol.tmpleaf2.*)
 393             if (( ${#tmpleaf[@]} )); then
 394               x btrfs sub del ${tmpleaf[@]}
 395             fi
 396             tmpleaf=($vol.tmpleaf1.*)
 397             if (( ${#tmpleaf[@]} )); then
 398               x mv ${tmpleaf[0]} $vol.tmpleaf2.${tmpleaf[0]#$vol.tmpleaf1.}
 399             fi
 400             echo suspected identical: $bsub $leaf
 401             x mv $leaf $vol.tmpleaf1.${leaf#$vol.leaf.}
 402           fi
 403         fi
 404       fi
 405     fi
 406     ### end check if leaf is different, delete it if not ###
 407
 408     ## begin expire leaf vols ##
 409     leaf_vols=($vol.leaf.*)
 410     count=${#leaf_vols[@]}
 411     leaf_limit_time=$(( $(date +%s) - 60*60*24*60 )) # 60 days
 412     leaf_new_limit_time=$(( $(date +%s) - 60*60*24 )) # 1 day
 413     # this goes backwards from oldest. leaf_new_limit_time is just in case
 414     # the order gets screwed up or something.
 415     for leaf in ${leaf_vols[@]}; do
 416       leaf_time=$(date -d ${leaf#$vol.leaf.} +%s)
 417       if (( leaf_limit_time > leaf_time || ( leaf_new_limit_time > leaf_time && count > 15 ) )); then
 418         x btrfs sub del $leaf
 419       fi
 420       count=$((count-1))
 421     done
 422     ## end expire leaf vols ##
 423   fi
 424   #### end dealing with leaf vols ####
 425
 426   # Note, we make a few assumptions in this script, like
 427   # $d was not a different subvol id than $vol, and
 428   # things otherwise didn't get mounted very strangely.
 429   m btrfs sub snapshot $fresh_snap $vol
 430   for dir in $d ${binds[@]}; do
 431     m mnt $dir
 432   done
 433   if [[ $vol == q ]]; then
 434     # maybe this will fail if X is not running
 435     x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user start arbtt ||:
 436   fi
 437   stale_dir=/nocow/btrfs-stale
 438   rm -f $stale_dir/$d
 439 done
 440
 441
 442
 443 for dir in /mnt/r7/amy/{root,boot}_ubuntubionic /mnt/{root2/root,boot2/boot}_ubuntubionic; do
 444   vol=${dir##*/}
 445   root_dir=${dir%/*}
 446   if [[ ! -d $root_dir ]]; then
 447     # this only exists on host kd currently
 448     continue
 449   fi
 450   # if latest is already mounted, make sure binds are mounted and move on
 451   m check-subvol-stale -p $dir
 452   # populated by check-subvol-stale if stale
 453   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 454     continue
 455   fi
 456   if [[ -d $dir ]]; then
 457     if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 458       if $force; then  kill-dir KILL; fi
 459     fi
 460     m btrfs sub del $dir
 461   fi
 462   m btrfs sub snapshot $fresh_snap $dir
 463   rm -f /nocow/btrfs-stale/$vol
 464 done
 465
 466 exit $ret
 467
 468