iankelling.org Git - distro-setup/blob - mount-latest-subvol

   1 #!/bin/bash
   2
   3 # On Ian's computers, mount received subvolumes after btrbk.
   4 # Copyright (C) 2024  Ian Kelling
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 # SPDX-License-Identifier: GPL-3.0-or-later
  20
  21 this_file="$(readlink -f -- "${BASH_SOURCE[0]}")"
  22 readonly this_file
  23 cd /
  24 [[ $EUID == 0 ]] || exec sudo -E "$this_file" "$@"
  25
  26 set -e; . /usr/local/lib/bash-bear; set +e
  27
  28 usage() {
  29   cat <<EOF
  30 Usage: ${0##*/} [OPTIONS] [SUBVOLUMES]
  31
  32 -h|--help  Print help and exit.
  33 -f|--force  Use kill -9 to try fixing unmount errors
  34 -v|--verbose  Be more verbose
  35
  36
  37 Note: In git this is not not executable because it's meant to be installed
  38 using ./install-my-scripts
  39
  40 Note: Uses util-linux getopt option parsing: spaces between args and
  41 options, short options can be combined, options before args.
  42 EOF
  43   exit $1
  44 }
  45
  46 pre="mount-latest-subvol:${SSH_CLIENT:+ $HOSTNAME:}"
  47
  48 tu() {
  49   while read -r line; do
  50     file="$1"
  51     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  52   done
  53 }
  54 d() {
  55   if $verbose; then
  56     printf "$pre %s\n" "$*"
  57   fi
  58 }
  59 m() {
  60   if $verbose; then
  61     printf "$pre %s\n" "$*"
  62   fi
  63   "$@"
  64 }
  65 x() {
  66   printf "$pre %s\n" "$*"
  67   "$@"
  68 }
  69
  70 mnt() {
  71   dir=$1
  72   if ! mountpoint -q $dir; then
  73     mkdir -p $dir
  74     m mount $dir
  75   fi
  76 }
  77 fstab() {
  78   while read -r start mpoint end; do
  79     l="$start $mpoint $end"
  80     # kill off any lines that duplicate the mount point.
  81     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
  82     tu /etc/fstab <<<"$l"
  83   done
  84 }
  85 pid-check() {
  86   for p in ${pids}; do
  87     for m in ${my_pids[@]}; do
  88       if (( p == m )); then
  89         echo "$0: error: pids to kill includes our pid or a parent. ps output:" >&2
  90         ps -f -p $p
  91         exit 1
  92       fi
  93     done
  94   done
  95 }
  96 kill-dir() {
  97   for sig; do
  98     echo kill-dir $sig
  99     found_pids=false
 100     if pids=$(timeout 4 lsof -t $dir); then
 101       found_pids=true
 102       timeout 4 lsof -w $dir
 103       pid-check
 104       kill -$sig $pids
 105     fi
 106     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 107     # note: -v shows kernel processes, which then doesn't return true when we want
 108     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 109       pid-check
 110       found_pids=true
 111       fuser -$sig -mvk $dir
 112     fi
 113     sleep .5
 114     if ! $found_pids; then
 115       return 0
 116     fi
 117   done
 118   return 1
 119 }
 120 umount-kill() {
 121   dir=$1
 122   if mountpoint -q $dir; then
 123     if m umount -R $dir; then
 124       unmounted+=($dir)
 125     else
 126       if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 127         if $force; then  kill-dir KILL; fi
 128       fi
 129
 130       if m umount -R $dir; then
 131         unmounted+=($dir)
 132       else
 133         echo "$0: failed to umount $dir"
 134         umount_ret=false
 135         ret=1
 136       fi
 137     fi
 138   fi
 139 }
 140
 141 # duplicated in check-subvol
 142 # Reassign $1 var from /dev/dm- to corresponding /dev/mapper/
 143 mapper-dev() {
 144   local mapdev
 145   local -n devref=$1
 146   if [[ $devref == /dev/dm-* ]]; then
 147     for mapdev in /dev/mapper/*; do
 148       if [[ $(readlink -f $mapdev) == "$devref" ]]; then
 149         devref=$mapdev
 150         break
 151       fi
 152     done
 153   fi
 154 }
 155
 156
 157 ##### begin command line parsing ########
 158
 159 # you can remove this if you do not have options which can have args with spaces or empty.
 160
 161 verbose=true
 162 force=false
 163 temp=$(getopt -l help,force,verbose hfv "$@") || usage 1
 164 eval set -- "$temp"
 165 while true; do
 166   case $1 in
 167     -f|--force) force=true ;;
 168     -v|--verbose) verbose=true ;;
 169     -h|--help) usage ;;
 170     --) shift; break ;;
 171     *) echo "$0: unexpected args: $*" >&2 ; usage 1 ;;
 172   esac
 173   shift
 174 done
 175
 176 if (( $# )); then
 177   all_vols=( "$@" )
 178 else
 179   all_vols=(q a o i ar qd qr)
 180 fi
 181
 182 ##### end command line parsing ########
 183
 184 ret=0
 185
 186 ##### begin setup fstab for subvols we care about ######
 187
 188 if [[ -e /mnt/root/root2-crypttab ]]; then
 189   tu /etc/crypttab </mnt/root/root2-crypttab
 190   while read -r mapper_dev _; do
 191     if [[ ! -e /dev/mapper/$mapper_dev ]]; then
 192       m cryptdisks_start $mapper_dev
 193     fi
 194   done < <(cat /mnt/root/root2-crypttab)
 195 fi
 196 if [[ -e /mnt/root/root2-fstab ]]; then
 197   tu /etc/fstab </mnt/root/root2-fstab
 198   mnt /mnt/root2
 199   mnt /mnt/boot2
 200 fi
 201
 202 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 203 mapper-dev root_dev
 204 o_dev=$(awk '$2 == "/mnt/o" {print $1}' /etc/mtab)
 205 mapper-dev o_dev
 206
 207
 208 # root2_dev=$(awk '$2 == "/mnt/root2" {print $1}' /etc/mtab)
 209 # mapper-dev root2_dev
 210 # # dont bother with the above for crypt2_dev
 211 # crypt2_dev=$root2_dev
 212
 213
 214 if cryptsetup status $root_dev &>/dev/null; then
 215   crypt_dev=$root_dev
 216 else # if we are in a recovery boot, find the next best crypt device
 217   mopts=,noauto
 218   # todo: I think I had an idea to not setup /o in this case,
 219   # but never finished implementing it
 220   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 221     dev=/dev/mapper/$dev
 222     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 223       crypt_dev=$dev
 224       break
 225     fi
 226   done
 227 fi
 228
 229
 230
 231 # dont tax the cpus of old laptops
 232 if (( $(nproc) > 2)); then
 233   mopts+=,compress=zstd
 234 fi
 235
 236 fstab <<EOF
 237 $crypt_dev  /a  btrfs  noatime,subvol=a$mopts  0 0
 238 EOF
 239
 240 shopt -s nullglob
 241
 242 # ssh and probably some other things care about parent directory
 243 # ownership, and ssh doesn\'t allow any group writable parent
 244 # directories, so we are forced to use a directory structure similar
 245 # to home directories
 246 fa=(/mnt/root/btrbk/q.*); f=${fa[0]}
 247 if [[ -e $f ]]; then
 248   fstab <<EOF
 249 $crypt_dev  /q  btrfs  noatime,subvol=q$mopts  0 0
 250 $crypt_dev  /qd  btrfs  noatime,subvol=qd$mopts  0 0
 251 /q/p  /p  none  bind$mopts  0 0
 252 EOF
 253 fi
 254
 255 fa=(/mnt/root/btrbk/qr.*); f=${fa[0]}
 256 if [[ -e $f ]]; then
 257   fstab <<EOF
 258 $crypt_dev  /qr  btrfs  noatime,subvol=qr$mopts  0 0
 259 EOF
 260 fi
 261
 262 # not syncing ar at the moment
 263 # fa=(/mnt/root/btrbk/ar.*); f=${fa[0]}
 264 # if [[ -e $f ]]; then
 265 #   fstab <<EOF
 266 # $crypt_dev  /ar  btrfs  noatime,subvol=ar,uid=1000$mopts  0 0
 267 # EOF
 268 # fi
 269
 270
 271 fa=(/mnt/o/btrbk/o.*); f=${fa[0]}
 272 if [[ -e $f ]]; then
 273   if [[ $o_dev != "$root_dev" ]]; then
 274     # ,compress=zstd regardless of mopts since these are all text files
 275     # and it cuts disk use by about half.
 276     fstab <<EOF
 277 $o_dev  /o  btrfs  noatime,subvol=o${mopts/,compress=zstd/},compress=zstd  0 0
 278 EOF
 279   fi
 280   fstab <<EOF
 281 /o/m  /m  none  bind$mopts  0 0
 282 /o/debbugs  /debbugs  none  bind$mopts  0 0
 283 EOF
 284 fi
 285
 286
 287 ##### end setup fstab for subvols we care about ######
 288
 289 ### begin get pids that this program depends on so we dont kill them
 290 my_pids=($$ $PPID)
 291 loop_limit=30
 292 count=0
 293 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != "${my_pids[-2]}" && $count -lt $loop_limit  ]]; do
 294   count=$((count + 1))
 295   p=$(ps -p ${my_pids[-1]} -o ppid=)
 296   if [[ $p == 0 || ! $p ]]; then
 297     break
 298   fi
 299   my_pids+=($p)
 300 done
 301 ### end get pids that this program depends on so we dont kill them
 302
 303 for vol in ${all_vols[@]}; do
 304   d=/$vol
 305   if ! awk '$3 == "btrfs" {print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 306     continue
 307   fi
 308
 309
 310   ##### begin building up list of bind mounts  ######
 311   binds=() # list of bind mounts
 312   roots=($d)
 313   while true; do
 314     new_roots=()
 315     for r in ${roots[@]}; do
 316       # eg. when r=/q/p, for lines like
 317       # /q/p  /p  none  bind  0 0
 318       # output /p
 319       new_roots+=("$(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+(\S+,|)bind[[:space:],].*#\1#p" /etc/fstab)")
 320     done
 321     (( ${#new_roots} )) || break
 322     binds+=(${new_roots[@]})
 323     # roots is used to recursively find binds of binds if they exist.
 324     roots=( ${new_roots[@]} )
 325   done
 326   ##### end building up list of bind mounts  ######
 327
 328
 329
 330   # if latest is already mounted, make sure binds are mounted and move on
 331   m check-subvol-stale $d
 332   # populated by check-subvol-stale if stale
 333   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 334     mnt $d
 335     did=$(stat -c%d $d)
 336     for b in ${binds[@]}; do
 337       if mountpoint -q $b; then
 338         bid=$(stat -c%d $b)
 339         if [[ $did != "$bid" ]]; then
 340           umount-kill $b
 341         fi
 342       fi
 343       mnt $b
 344     done
 345     continue
 346   fi
 347
 348
 349   ##### begin checking for loopback mounts ####
 350   found_loop=false
 351   for l in $(losetup -ln|awk '{print $6}'); do
 352     for dir in $d ${binds[@]}; do
 353       if [[ $l == $dir* ]]; then
 354         echo "$0: found loopback mount $l. giving up on unmounting $dir"
 355         ret=1
 356         found_loop=true
 357         break
 358       fi
 359     done
 360     if $found_loop; then
 361       break
 362     fi
 363   done
 364   if $found_loop; then
 365     continue
 366   fi
 367   ##### end end checking loopback mounts ####
 368
 369
 370   ## not using arbtt at the moment
 371   # if [[ $vol == q ]]; then
 372   #   ## allow to fail, user might not be logged in
 373   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user stop arbtt ||:
 374   # fi
 375   umount_ret=true
 376   unmounted=()
 377   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 378     umount-kill $dir
 379   done
 380
 381   # if we unmounted some but not all, restore them and move on
 382   if ! $umount_ret; then
 383     for dir in ${unmounted[@]}; do
 384       mnt $dir
 385     done
 386     continue
 387   fi
 388
 389   #### begin dealing with leaf vols ####
 390
 391   ### begin getting root_dir
 392   ### this is duplicated in check-subvol-stale
 393
 394   dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab /etc/mtab|head -n1)
 395   d dev=$dev
 396   # note, we need $dev because $d might not be mounted, and we do this loop
 397   # because the device in fstab for the rootfs can be different.
 398   for devx in $(btrfs fil show $dev| sed -rn 's#.*path (\S+)$#\1#p'); do
 399     if [[ $devx == dm-* ]]; then
 400       devx=/dev/$devx
 401       mapper-dev devx
 402     fi
 403     d devx=$devx
 404     root_dir=$(sed -rn "s,^\s*$devx\s+(\S+).*\bsubvolid=[05]\b.*,\1,p" /etc/mtab /etc/fstab|head -n1)
 405     if [[ $root_dir ]]; then
 406       d root_dir=$root_dir
 407       break
 408     fi
 409   done
 410   if [[ ! $root_dir ]]; then
 411     echo "$0: error could not find root subvol mount for $dev" >&2
 412     exit 1
 413   fi
 414   ### end getting root_dir
 415
 416   cd $root_dir
 417   if [[ -e $vol  ]]; then
 418     if [[ $vol == qd ]]; then
 419       m btrfs sub del qd
 420     else
 421       leaf=$vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 422       m mv $vol $leaf
 423       m btrfs property set -ts $leaf ro true
 424
 425       ### begin check if leaf is different, delete it if not ###
 426       parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
 427       bsubs=(btrbk/$vol.*)
 428       bsub= # base subvolume
 429       # go in reverse order as its more likely to be at the end
 430       for ((i=${#bsubs[@]}-1; i>=0; i--)); do
 431         if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
 432           bsub=${bsubs[i]}
 433           break
 434         fi
 435       done
 436       if [[ $bsub ]]; then
 437         # in testing, same subvol is 136 bytes. allow some overhead. 32 happens sometimes under systemd.
 438         # $ errno 32
 439         # EPIPE 32 Broken pipe
 440         lines=$(btrfs send --no-data -p $bsub $leaf | btrfs receive --dump | head -n 100 | wc -l || [[ $? == 141 || ${PIPESTATUS[0]} == 32 ]])
 441         if [[ $lines == 0 ]]; then
 442           # example output of no differences:
 443           # snapshot        ./qrtest                        uuid=c41ff6b7-0527-f34d-95ac-190eecf54ff5 transid=2239 parent_uuid=64949e1b-4a3e-3945-9a8e-cd7b7c15d7d6 parent_transid=2239
 444           echo suspected identical: $bsub $leaf
 445           x btrfs sub del $leaf
 446         fi
 447       fi
 448       ### end check if leaf is different, delete it if not ###
 449
 450       ## begin expire leaf vols ##
 451       leaf_vols=($vol.leaf.*)
 452       count=${#leaf_vols[@]}
 453       leaf_limit_time=$(( EPOCHSECONDS - 60*60*24*60 )) # 60 days
 454       leaf_new_limit_time=$(( EPOCHSECONDS - 60*60*24 * 5 )) # 5 days this
 455       # goes backwards from oldest. leaf_new_limit_time is a safety
 456       # measure to ensure we don't delete very recent leafs.
 457       for leaf in ${leaf_vols[@]}; do
 458         leaf_time=$(date -d ${leaf#"$vol".leaf.} +%s)
 459         if (( leaf_limit_time > leaf_time || ( leaf_new_limit_time > leaf_time && count > 30 ) )); then
 460           x btrfs sub del $leaf
 461         fi
 462         count=$((count-1))
 463       done
 464     fi
 465     ## end expire leaf vols ##
 466   fi
 467   #### end dealing with leaf vols ####
 468
 469   # Note, we make a few assumptions in this script, like
 470   # $d was not a different subvol id than $vol, and
 471   # things otherwise didn't get mounted very strangely.
 472   m btrfs sub snapshot $fresh_snap $vol
 473   for dir in $d ${binds[@]}; do
 474     m mnt $dir
 475   done
 476
 477   ## arbtt disabled for now
 478   # if [[ $vol == q ]]; then
 479   #   # maybe this will fail if X is not running
 480   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user start arbtt ||:
 481   # fi
 482
 483   stale_dir=/nocow/btrfs-stale
 484   rm -f $stale_dir/$d
 485 done
 486
 487
 488
 489 for dir in /mnt/r7/amy/{root/root,boot/boot}_ubuntubionic /mnt/{root2/root,boot2/boot}_ubuntubionic; do
 490   vol=${dir##*/}
 491   root_dir=${dir%/*}
 492   if [[ ! -d $root_dir ]]; then
 493     # this only exists on host kd currently
 494     continue
 495   fi
 496   # if latest is already mounted, make sure binds are mounted and move on
 497   m check-subvol-stale -p $dir
 498   # populated by check-subvol-stale if stale
 499   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 500     continue
 501   fi
 502   if [[ -d $dir ]]; then
 503     if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 504       if $force; then  kill-dir KILL; fi
 505     fi
 506     m btrfs sub del $dir
 507   fi
 508   m btrfs sub snapshot $fresh_snap $dir
 509   rm -f /nocow/btrfs-stale/$vol
 510 done
 511
 512 if (( ret >= 1 )); then
 513   echo "$0: exit status $ret. see error above"
 514 fi
 515 exit $ret
 516
 517