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] [SUBVOLUMES]
  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: In git this is not not executable because it's meant to be installed
  32 using ./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
  42 tu() {
  43   while read -r line; do
  44     file="$1"
  45     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  46   done
  47 }
  48 d() {
  49   if $verbose; then
  50     printf "%s\n" "$*"
  51   fi
  52 }
  53 m() {
  54   if $verbose; then
  55     printf "%s\n" "$*"
  56   fi
  57   "$@"
  58 }
  59 x() {
  60   printf "%s\n" "$*"
  61   "$@"
  62 }
  63
  64 mnt() {
  65   dir=$1
  66   if ! mountpoint -q $dir; then
  67     mkdir -p $dir
  68     m mount $dir
  69   fi
  70 }
  71 fstab() {
  72   while read -r start mpoint end; do
  73     l="$start $mpoint $end"
  74     # kill off any lines that duplicate the mount point.
  75     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
  76     tu /etc/fstab <<<"$l"
  77   done
  78 }
  79 pid-check() {
  80   for p in ${pids}; do
  81     for m in ${my_pids[@]}; do
  82       if (( p == m )); then
  83         echo "$0: error: pids to kill includes our pid or a parent. ps output:" >&2
  84         ps -f -p $p
  85         exit 1
  86       fi
  87     done
  88   done
  89 }
  90 kill-dir() {
  91   for sig; do
  92     echo kill-dir $sig
  93     found_pids=false
  94     if pids=$(timeout 4 lsof -t $dir); then
  95       found_pids=true
  96       timeout 4 lsof -w $dir
  97       pid-check
  98       kill -$sig $pids
  99     fi
 100     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 101     # note: -v shows kernel processes, which then doesn't return true when we want
 102     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 103       pid-check
 104       found_pids=true
 105       fuser -$sig -mvk $dir
 106     fi
 107     sleep .5
 108     if ! $found_pids; then
 109       return 0
 110     fi
 111   done
 112   return 1
 113 }
 114 umount-kill() {
 115   dir=$1
 116   if mountpoint -q $dir; then
 117     if m umount -R $dir; then
 118       unmounted+=($dir)
 119     else
 120       if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 121         if $force; then  kill-dir KILL; fi
 122       fi
 123
 124       if m umount -R $dir; then
 125         unmounted+=($dir)
 126       else
 127         echo "$0: failed to umount $dir"
 128         umount_ret=false
 129         ret=1
 130       fi
 131     fi
 132   fi
 133 }
 134
 135 # duplicated in check-subvol
 136 # Reassign $1 var from /dev/dm- to corresponding /dev/mapper/
 137 mapper-dev() {
 138   local mapdev
 139   local -n devref=$1
 140   if [[ $devref == /dev/dm-* ]]; then
 141     for mapdev in /dev/mapper/*; do
 142       if [[ $(readlink -f $mapdev) == "$devref" ]]; then
 143         devref=$mapdev
 144         break
 145       fi
 146     done
 147   fi
 148 }
 149
 150
 151 ##### begin command line parsing ########
 152
 153 # you can remove this if you do not have options which can have args with spaces or empty.
 154
 155 verbose=true
 156 force=false
 157 temp=$(getopt -l help,force,verbose hfv "$@") || usage 1
 158 eval set -- "$temp"
 159 while true; do
 160   case $1 in
 161     -f|--force) force=true ;;
 162     -v|--verbose) verbose=true ;;
 163     -h|--help) usage ;;
 164     --) shift; break ;;
 165     *) echo "$0: unexpected args: $*" >&2 ; usage 1 ;;
 166   esac
 167   shift
 168 done
 169
 170 if (( $# )); then
 171   all_vols=( "$@" )
 172 else
 173   all_vols=(q a o i ar qr)
 174 fi
 175
 176 ##### end command line parsing ########
 177
 178 ret=0
 179
 180 ##### begin setup fstab for subvols we care about ######
 181
 182 if [[ -e /mnt/root/root2-crypttab ]]; then
 183   tu /etc/crypttab </mnt/root/root2-crypttab
 184   while read -r mapper_dev _; do
 185     if [[ ! -e /dev/mapper/$mapper_dev ]]; then
 186       m cryptdisks_start $mapper_dev
 187     fi
 188   done < <(cat /mnt/root/root2-crypttab)
 189 fi
 190 if [[ -e /mnt/root/root2-fstab ]]; then
 191   tu /etc/fstab </mnt/root/root2-fstab
 192   mnt /mnt/root2
 193   mnt /mnt/boot2
 194 fi
 195
 196 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 197 mapper-dev root_dev
 198 o_dev=$(awk '$2 == "/mnt/o" {print $1}' /etc/mtab)
 199 mapper-dev o_dev
 200
 201
 202 # root2_dev=$(awk '$2 == "/mnt/root2" {print $1}' /etc/mtab)
 203 # mapper-dev root2_dev
 204 # # dont bother with the above for crypt2_dev
 205 # crypt2_dev=$root2_dev
 206
 207
 208 if cryptsetup status $root_dev &>/dev/null; then
 209   crypt_dev=$root_dev
 210 else # if we are in a recovery boot, find the next best crypt device
 211   mopts=,noauto
 212   # todo: I think I had an idea to not setup /o in this case,
 213   # but never finished implementing it
 214   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 215     dev=/dev/mapper/$dev
 216     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 217       crypt_dev=$dev
 218       break
 219     fi
 220   done
 221 fi
 222
 223
 224
 225 # dont tax the cpus of old laptops
 226 if (( $(nproc) > 2)); then
 227   mopts+=,compress=zstd
 228 fi
 229
 230 fstab <<EOF
 231 $crypt_dev  /a  btrfs  noatime,subvol=a$mopts  0 0
 232 EOF
 233
 234 shopt -s nullglob
 235
 236 # ssh and probably some other things care about parent directory
 237 # ownership, and ssh doesn\'t allow any group writable parent
 238 # directories, so we are forced to use a directory structure similar
 239 # to home directories
 240 fa=(/mnt/root/btrbk/q.*); f=${fa[0]}
 241 if [[ -e $f ]]; then
 242   fstab <<EOF
 243 $crypt_dev  /q  btrfs  noatime,subvol=q,gid=1000$mopts  0 0
 244 /q/p  /p  none  bind$mopts  0 0
 245 EOF
 246 fi
 247
 248 fa=(/mnt/root/btrbk/qr.*); f=${fa[0]}
 249 if [[ -e $f ]]; then
 250   fstab <<EOF
 251 $crypt_dev  /qr  btrfs  noatime,subvol=qr$mopts  0 0
 252 EOF
 253 fi
 254
 255 fa=(/mnt/root/btrbk/ar.*); f=${fa[0]}
 256 if [[ -e $f ]]; then
 257   fstab <<EOF
 258 $crypt_dev  /ar  btrfs  noatime,subvol=ar,uid=1000,gid=1000$mopts  0 0
 259 EOF
 260 fi
 261
 262
 263 fa=(/mnt/o/btrbk/o.*); f=${fa[0]}
 264 if [[ -e $f ]]; then
 265   if [[ $o_dev != "$root_dev" ]]; then
 266     fstab <<EOF
 267 $o_dev  /o  btrfs  noatime,subvol=o$mopts  0 0
 268 EOF
 269   fi
 270   fstab <<EOF
 271 /o/m  /m  none  bind$mopts  0 0
 272 EOF
 273 fi
 274
 275
 276 ##### end setup fstab for subvols we care about ######
 277
 278 ### begin get pids that this program depends on so we dont kill them
 279 my_pids=($$ $PPID)
 280 loop_limit=30
 281 count=0
 282 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != "${my_pids[-2]}" && $count -lt $loop_limit  ]]; do
 283   count=$((count + 1))
 284   p=$(ps -p ${my_pids[-1]} -o ppid=)
 285   if [[ $p == 0 || ! $p ]]; then
 286     break
 287   fi
 288   my_pids+=($p)
 289 done
 290 ### end get pids that this program depends on so we dont kill them
 291
 292 for vol in ${all_vols[@]}; do
 293   d=/$vol
 294   if ! awk '$3 == "btrfs" {print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 295     continue
 296   fi
 297
 298
 299   ##### begin building up list of bind mounts  ######
 300   binds=() # list of bind mounts
 301   roots=($d)
 302   while true; do
 303     new_roots=()
 304     for r in ${roots[@]}; do
 305       # eg. when r=/q/p, for lines like
 306       # /q/p  /p  none  bind  0 0
 307       # output /p
 308       new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+(\S+,|)bind[[:space:],].*#\1#p" /etc/fstab))
 309     done
 310     (( ${#new_roots} )) || break
 311     binds+=(${new_roots[@]})
 312     # roots is used to recursively find binds of binds if they exist.
 313     roots=( ${new_roots[@]} )
 314   done
 315   ##### end building up list of bind mounts  ######
 316
 317
 318   # if latest is already mounted, make sure binds are mounted and move on
 319   m check-subvol-stale $d
 320   # populated by check-subvol-stale if stale
 321   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 322     mnt $d
 323     did=$(stat -c%d $d)
 324     for b in ${binds[@]}; do
 325       if mountpoint -q $b; then
 326         bid=$(stat -c%d $b)
 327         if [[ $did != "$bid" ]]; then
 328           umount-kill $b
 329         fi
 330       fi
 331       mnt $b
 332     done
 333     continue
 334   fi
 335
 336   ## not using arbtt at the moment
 337   # if [[ $vol == q ]]; then
 338   #   ## allow to fail, user might not be logged in
 339   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user stop arbtt ||:
 340   # fi
 341   umount_ret=true
 342   unmounted=()
 343   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 344     umount-kill $dir
 345   done
 346
 347   # if we unmounted some but not all, restore them and move on
 348   if ! $umount_ret; then
 349     for dir in ${unmounted[@]}; do
 350       mnt $dir
 351     done
 352     continue
 353   fi
 354
 355   #### begin dealing with leaf vols ####
 356
 357   ### begin getting root_dir
 358   ### this is duplicated in check-subvol-stale
 359
 360   dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab /etc/mtab|head -n1)
 361   d dev=$dev
 362   # note, we need $dev because $d might not be mounted, and we do this loop
 363   # because the device in fstab for the rootfs can be different.
 364   for devx in $(btrfs fil show $dev| sed -rn 's#.*path (\S+)$#\1#p'); do
 365     if [[ $devx == dm-* ]]; then
 366       devx=/dev/$devx
 367       mapper-dev devx
 368     fi
 369     d devx=$devx
 370     root_dir=$(sed -rn "s,^\s*$devx\s+(\S+).*\bsubvolid=[05]\b.*,\1,p" /etc/mtab /etc/fstab|head -n1)
 371     if [[ $root_dir ]]; then
 372       d root_dir=$root_dir
 373       break
 374     fi
 375   done
 376   if [[ ! $root_dir ]]; then
 377     echo "$0: error could not find root subvol mount for $dev" >&2
 378     exit 1
 379   fi
 380   ### end getting root_dir
 381
 382   cd $root_dir
 383   if [[ -e $vol ]]; then
 384     leaf=$vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 385     m mv $vol $leaf
 386     m btrfs property set -ts $leaf ro true
 387
 388     ### begin check if leaf is different, delete it if not ###
 389     parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
 390     bsubs=(btrbk/$vol.*)
 391     bsub= # base subvolume
 392     # go in reverse order as its more likely to be at the end
 393     for ((i=${#bsubs[@]}-1; i>=0; i--)); do
 394       if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
 395         bsub=${bsubs[i]}
 396         break
 397       fi
 398     done
 399     if [[ $bsub ]]; then
 400       # in testing, same subvol is 136 bytes. allow some overhead. 32 happens sometimes under systemd.
 401       # $ errno 32
 402       # EPIPE 32 Broken pipe
 403       lines=$(btrfs send --no-data -p $bsub $leaf | btrfs receive --dump | head -n 100 | wc -l || [[ $? == 141 || ${PIPESTATUS[0]} == 32 ]])
 404       if [[ $lines == 0 ]]; then
 405         # example output of no differences:
 406         # snapshot        ./qrtest                        uuid=c41ff6b7-0527-f34d-95ac-190eecf54ff5 transid=2239 parent_uuid=64949e1b-4a3e-3945-9a8e-cd7b7c15d7d6 parent_transid=2239
 407         echo suspected identical: $bsub $leaf
 408         x btrfs sub del $leaf
 409       fi
 410     fi
 411     ### end check if leaf is different, delete it if not ###
 412
 413     ## begin expire leaf vols ##
 414     leaf_vols=($vol.leaf.*)
 415     count=${#leaf_vols[@]}
 416     leaf_limit_time=$(( EPOCHSECONDS - 60*60*24*60 )) # 60 days
 417     leaf_new_limit_time=$(( EPOCHSECONDS - 60*60*24 )) # 1 day
 418     # this goes backwards from oldest. leaf_new_limit_time is just in case
 419     # the order gets screwed up or something.
 420     for leaf in ${leaf_vols[@]}; do
 421       leaf_time=$(date -d ${leaf#"$vol".leaf.} +%s)
 422       if (( leaf_limit_time > leaf_time || ( leaf_new_limit_time > leaf_time && count > 15 ) )); then
 423         x btrfs sub del $leaf
 424       fi
 425       count=$((count-1))
 426     done
 427     ## end expire leaf vols ##
 428   fi
 429   #### end dealing with leaf vols ####
 430
 431   # Note, we make a few assumptions in this script, like
 432   # $d was not a different subvol id than $vol, and
 433   # things otherwise didn't get mounted very strangely.
 434   m btrfs sub snapshot $fresh_snap $vol
 435   for dir in $d ${binds[@]}; do
 436     m mnt $dir
 437   done
 438
 439   ## arbtt disabled for now
 440   # if [[ $vol == q ]]; then
 441   #   # maybe this will fail if X is not running
 442   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user start arbtt ||:
 443   # fi
 444
 445   stale_dir=/nocow/btrfs-stale
 446   rm -f $stale_dir/$d
 447 done
 448
 449
 450
 451 for dir in /mnt/r7/amy/{root/root,boot/boot}_ubuntubionic /mnt/{root2/root,boot2/boot}_ubuntubionic; do
 452   vol=${dir##*/}
 453   root_dir=${dir%/*}
 454   if [[ ! -d $root_dir ]]; then
 455     # this only exists on host kd currently
 456     continue
 457   fi
 458   # if latest is already mounted, make sure binds are mounted and move on
 459   m check-subvol-stale -p $dir
 460   # populated by check-subvol-stale if stale
 461   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 462     continue
 463   fi
 464   if [[ -d $dir ]]; then
 465     if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 466       if $force; then  kill-dir KILL; fi
 467     fi
 468     m btrfs sub del $dir
 469   fi
 470   m btrfs sub snapshot $fresh_snap $dir
 471   rm -f /nocow/btrfs-stale/$vol
 472 done
 473
 474 exit $ret
 475
 476