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: 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 all_vols=(q a o i ar qr)
  41
  42
  43 tu() {
  44   while read -r line; do
  45     file="$1"
  46     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  47   done
  48 }
  49 d() {
  50   if $verbose; then
  51     printf "%s\n" "$*"
  52   fi
  53 }
  54 m() {
  55   if $verbose; then
  56     printf "%s\n" "$*"
  57   fi
  58   "$@"
  59 }
  60 x() {
  61   printf "%s\n" "$*"
  62   "$@"
  63 }
  64
  65 mnt() {
  66   dir=$1
  67   if ! mountpoint -q $dir; then
  68     mkdir -p $dir
  69     m mount $dir
  70   fi
  71 }
  72 fstab() {
  73   while read -r start mpoint end; do
  74     l="$start $mpoint $end"
  75     # kill off any lines that duplicate the mount point.
  76     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
  77     tu /etc/fstab <<<"$l"
  78   done
  79 }
  80 pid-check() {
  81   for p in ${pids}; do
  82     for m in ${my_pids[@]}; do
  83       if (( p == m )); then
  84         echo "$0: error: pids to kill includes our pid or a parent. ps output:" >&2
  85         ps -f -p $p
  86         exit 1
  87       fi
  88     done
  89   done
  90 }
  91 kill-dir() {
  92   for sig; do
  93     echo kill-dir $sig
  94     found_pids=false
  95     if pids=$(timeout 4 lsof -t $dir); then
  96       found_pids=true
  97       timeout 4 lsof -w $dir
  98       pid-check
  99       kill -$sig $pids
 100     fi
 101     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 102     # note: -v shows kernel processes, which then doesn't return true when we want
 103     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 104       pid-check
 105       found_pids=true
 106       fuser -$sig -mvk $dir
 107     fi
 108     sleep .5
 109     if ! $found_pids; then
 110       return 0
 111     fi
 112   done
 113   return 1
 114 }
 115 umount-kill() {
 116   dir=$1
 117   if mountpoint -q $dir; then
 118     if m umount -R $dir; then
 119       unmounted+=($dir)
 120     else
 121       if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 122         if $force; then  kill-dir KILL; fi
 123       fi
 124
 125       if m umount -R $dir; then
 126         unmounted+=($dir)
 127       else
 128         echo "$0: failed to umount $dir"
 129         umount_ret=false
 130         ret=1
 131       fi
 132     fi
 133   fi
 134 }
 135
 136 # duplicated in check-subvol
 137 # Reassign $1 var from /dev/dm- to corresponding /dev/mapper/
 138 mapper-dev() {
 139   local mapdev
 140   local -n devref=$1
 141   if [[ $devref == /dev/dm-* ]]; then
 142     for mapdev in /dev/mapper/*; do
 143       if [[ $(readlink -f $mapdev) == "$devref" ]]; then
 144         devref=$mapdev
 145         break
 146       fi
 147     done
 148   fi
 149 }
 150
 151
 152 ##### begin command line parsing ########
 153
 154 # you can remove this if you do not have options which can have args with spaces or empty.
 155
 156 verbose=true
 157 force=false
 158 temp=$(getopt -l help,force,verbose hfv "$@") || usage 1
 159 eval set -- "$temp"
 160 while true; do
 161   case $1 in
 162     -f|--force) force=true ;;
 163     -v|--verbose) verbose=true ;;
 164     -h|--help) usage ;;
 165     --) shift; break ;;
 166     *) echo "$0: unexpected args: $*" >&2 ; usage 1 ;;
 167   esac
 168   shift
 169 done
 170
 171 ##### end command line parsing ########
 172
 173 ret=0
 174
 175 ##### begin setup fstab for subvols we care about ######
 176
 177 if [[ -e /mnt/root/root2-crypttab ]]; then
 178   tu /etc/crypttab </mnt/root/root2-crypttab
 179   while read -r mapper_dev _; do
 180     if [[ ! -e /dev/mapper/$mapper_dev ]]; then
 181       m cryptdisks_start $mapper_dev
 182     fi
 183   done < <(cat /mnt/root/root2-crypttab)
 184 fi
 185 if [[ -e /mnt/root/root2-fstab ]]; then
 186   tu /etc/fstab </mnt/root/root2-fstab
 187   mnt /mnt/root2
 188   mnt /mnt/boot2
 189 fi
 190
 191 do_o=true
 192 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 193 mapper-dev root_dev
 194 o_dev=$(awk '$2 == "/mnt/o" {print $1}' /etc/mtab)
 195 mapper-dev o_dev
 196
 197 if [[ $o_dev == "$root_dev" ]]; then
 198   do_o=false
 199 fi
 200
 201 # root2_dev=$(awk '$2 == "/mnt/root2" {print $1}' /etc/mtab)
 202 # mapper-dev root2_dev
 203 # # dont bother with the above for crypt2_dev
 204 # crypt2_dev=$root2_dev
 205
 206
 207 if cryptsetup status $root_dev &>/dev/null; then
 208   crypt_dev=$root_dev
 209 else # if we are in a recovery boot, find the next best crypt device
 210   mopts=,noauto
 211   do_o=false
 212   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 213     dev=/dev/mapper/$dev
 214     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 215       crypt_dev=$dev
 216       break
 217     fi
 218   done
 219 fi
 220
 221
 222
 223 # dont tax the cpus of old laptops
 224 if ((`nproc` > 2)); then
 225   mopts+=,compress=zstd
 226 fi
 227
 228 fstab <<EOF
 229 $crypt_dev  /a  btrfs  noatime,subvol=a$mopts  0 0
 230 EOF
 231
 232 shopt -s nullglob
 233
 234 # ssh and probably some other things care about parent directory
 235 # ownership, and ssh doesn\'t allow any group writable parent
 236 # directories, so we are forced to use a directory structure similar
 237 # to home directories
 238 f=(/mnt/root/btrbk/q.*); f=${f[0]}
 239 if [[ -e $f ]]; then
 240   fstab <<EOF
 241 $crypt_dev  /q  btrfs  noatime,subvol=q,gid=1000$mopts  0 0
 242 /q/p  /p  none  bind$mopts  0 0
 243 EOF
 244 fi
 245
 246 f=(/mnt/root/btrbk/qr.*); f=${f[0]}
 247 if [[ -e $f ]]; then
 248   fstab <<EOF
 249 $crypt_dev  /qr  btrfs  noatime,subvol=qr$mopts  0 0
 250 EOF
 251 fi
 252
 253 f=(/mnt/root/btrbk/ar.*); f=${f[0]}
 254 if [[ -e $f ]]; then
 255   fstab <<EOF
 256 $crypt_dev  /ar  btrfs  noatime,subvol=ar,uid=1000,gid=1000$mopts  0 0
 257 EOF
 258 fi
 259
 260
 261 f=(/mnt/o/btrbk/o.*); f=${f[0]}
 262 if [[ -e $f ]]; then
 263   fstab <<EOF
 264 $o_dev  /o  btrfs  noatime,subvol=o$mopts  0 0
 265 /o/m  /m  none  bind$mopts  0 0
 266 EOF
 267 else
 268   do_o=false
 269 fi
 270
 271
 272 ##### end setup fstab for subvols we care about ######
 273
 274 ### begin get pids that this program depends on so we dont kill them
 275 my_pids=($$ $PPID)
 276 loop_limit=30
 277 count=0
 278 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != ${my_pids[-2]} && $count -lt $loop_limit  ]]; do
 279   count=$((count + 1))
 280   p=$(ps -p ${my_pids[-1]} -o ppid=)
 281   if [[ $p == 0 || ! $p ]]; then
 282     break
 283   fi
 284   my_pids+=($p)
 285 done
 286 ### end get pids that this program depends on so we dont kill them
 287
 288 for vol in ${all_vols[@]}; do
 289   d=/$vol
 290   if ! awk '{print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 291     continue
 292   fi
 293
 294
 295   ##### begin building up list of bind mounts  ######
 296   binds=() # list of bind mounts
 297   roots=($d)
 298   while true; do
 299     new_roots=()
 300     for r in ${roots[@]}; do
 301       # eg. when r=/q/p, for lines like
 302       # /q/p  /p  none  bind  0 0
 303       # output /p
 304       new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+(\S+,|)bind[[:space:],].*#\1#p" /etc/fstab))
 305     done
 306     (( ${#new_roots} )) || break
 307     binds+=(${new_roots[@]})
 308     # roots is used to recursively find binds of binds if they exist.
 309     roots=( ${new_roots[@]} )
 310   done
 311   ##### end building up list of bind mounts  ######
 312
 313
 314   # if latest is already mounted, make sure binds are mounted and move on
 315   m check-subvol-stale $d
 316   # populated by check-subvol-stale if stale
 317   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 318     mnt $d
 319     did=$(stat -c%d $d)
 320     for b in ${binds[@]}; do
 321       if mountpoint -q $b; then
 322         bid=$(stat -c%d $b)
 323         if [[ $did != $bid ]]; then
 324           umount-kill $b
 325         fi
 326       fi
 327       mnt $b
 328     done
 329     continue
 330   fi
 331
 332   ## not using arbtt at the moment
 333   # if [[ $vol == q ]]; then
 334   #   ## allow to fail, user might not be logged in
 335   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user stop arbtt ||:
 336   # fi
 337   umount_ret=true
 338   unmounted=()
 339   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 340     umount-kill $dir
 341   done
 342
 343   # if we unmounted some but not all, restore them and move on
 344   if ! $umount_ret; then
 345     for dir in ${unmounted[@]}; do
 346       mnt $dir
 347     done
 348     continue
 349   fi
 350
 351   #### begin dealing with leaf vols ####
 352
 353   ### begin getting root_dir
 354   ### this is duplicated in check-subvol-stale
 355
 356   dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab /etc/mtab|head -n1)
 357   d dev=$dev
 358   # note, we need $dev because $d might not be mounted, and we do this loop
 359   # because the device in fstab for the rootfs can be different.
 360   for devx in $(btrfs fil show $dev| sed -rn 's#.*path (\S+)$#\1#p'); do
 361     if [[ $devx == dm-* ]]; then
 362       devx=/dev/$devx
 363       mapper-dev devx
 364     fi
 365     d devx=$devx
 366     root_dir=$(sed -rn "s,^\s*$devx\s+(\S+).*\bsubvolid=[05]\b.*,\1,p" /etc/mtab /etc/fstab|head -n1)
 367     if [[ $root_dir ]]; then
 368       d root_dir=$root_dir
 369       break
 370     fi
 371   done
 372   if [[ ! $root_dir ]]; then
 373     echo "$0: error could not find root subvol mount for $dev" >&2
 374     exit 1
 375   fi
 376   ### end getting root_dir
 377
 378   cd $root_dir
 379   if [[ -e $vol ]]; then
 380     leaf=$vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 381     m mv $vol $leaf
 382     m btrfs property set -ts $leaf ro true
 383
 384     ### begin check if leaf is different, delete it if not ###
 385     parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
 386     bsubs=(btrbk/$vol.*)
 387     bsub= # base subvolume
 388     # go in reverse order as its more likely to be at the end
 389     for ((i=${#bsubs[@]}-1; i>=0; i--)); do
 390       if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
 391         bsub=${bsubs[i]}
 392         break
 393       fi
 394     done
 395     if [[ $bsub ]]; then
 396       tmp=$(mktemp)
 397       # in testing, same subvol is 136 bytes. allow some overhead. 32 happens sometimes under systemd.
 398       # $ errno 32
 399       # EPIPE 32 Broken pipe
 400       lines=$(btrfs send --no-data -p $bsub $leaf | btrfs receive --dump | head -n 100 | wc -l || [[ $? == 141 || ${PIPESTATUS[0]} == 32 ]])
 401       if [[ $lines == 0 ]]; then
 402         # example output of no differences:
 403         # snapshot        ./qrtest                        uuid=c41ff6b7-0527-f34d-95ac-190eecf54ff5 transid=2239 parent_uuid=64949e1b-4a3e-3945-9a8e-cd7b7c15d7d6 parent_transid=2239
 404         echo suspected identical: $bsub $leaf
 405         x btrfs sub del $leaf
 406       fi
 407     fi
 408     ### end check if leaf is different, delete it if not ###
 409
 410     ## begin expire leaf vols ##
 411     leaf_vols=($vol.leaf.*)
 412     count=${#leaf_vols[@]}
 413     leaf_limit_time=$(( EPOCHSECONDS - 60*60*24*60 )) # 60 days
 414     leaf_new_limit_time=$(( EPOCHSECONDS - 60*60*24 )) # 1 day
 415     # this goes backwards from oldest. leaf_new_limit_time is just in case
 416     # the order gets screwed up or something.
 417     for leaf in ${leaf_vols[@]}; do
 418       leaf_time=$(date -d ${leaf#$vol.leaf.} +%s)
 419       if (( leaf_limit_time > leaf_time || ( leaf_new_limit_time > leaf_time && count > 15 ) )); then
 420         x btrfs sub del $leaf
 421       fi
 422       count=$((count-1))
 423     done
 424     ## end expire leaf vols ##
 425   fi
 426   #### end dealing with leaf vols ####
 427
 428   # Note, we make a few assumptions in this script, like
 429   # $d was not a different subvol id than $vol, and
 430   # things otherwise didn't get mounted very strangely.
 431   m btrfs sub snapshot $fresh_snap $vol
 432   for dir in $d ${binds[@]}; do
 433     m mnt $dir
 434   done
 435
 436   ## arbtt disabled for now
 437   # if [[ $vol == q ]]; then
 438   #   # maybe this will fail if X is not running
 439   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user start arbtt ||:
 440   # fi
 441
 442   stale_dir=/nocow/btrfs-stale
 443   rm -f $stale_dir/$d
 444 done
 445
 446
 447
 448 for dir in /mnt/r7/amy/{root/root,boot/boot}_ubuntubionic /mnt/{root2/root,boot2/boot}_ubuntubionic; do
 449   vol=${dir##*/}
 450   root_dir=${dir%/*}
 451   if [[ ! -d $root_dir ]]; then
 452     # this only exists on host kd currently
 453     continue
 454   fi
 455   # if latest is already mounted, make sure binds are mounted and move on
 456   m check-subvol-stale -p $dir
 457   # populated by check-subvol-stale if stale
 458   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 459     continue
 460   fi
 461   if [[ -d $dir ]]; then
 462     if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 463       if $force; then  kill-dir KILL; fi
 464     fi
 465     m btrfs sub del $dir
 466   fi
 467   m btrfs sub snapshot $fresh_snap $dir
 468   rm -f /nocow/btrfs-stale/$vol
 469 done
 470
 471 exit $ret
 472
 473