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 shopt -s nullglob
  28
  29 usage() {
  30   cat <<EOF
  31 Usage: ${0##*/} [OPTIONS] [SUBVOLUMES]
  32
  33 -h|--help  Print help and exit.
  34 -f|--force  Use kill -9 to try fixing unmount errors
  35 -v|--verbose  Be more verbose
  36
  37
  38 Note: In git this is not not executable because it's meant to be installed
  39 using ./install-my-scripts
  40
  41 Note: Uses util-linux getopt option parsing: spaces between args and
  42 options, short options can be combined, options before args.
  43 EOF
  44   exit $1
  45 }
  46
  47 pre="mount-latest-subvol:${SSH_CLIENT:+ $HOSTNAME:}"
  48
  49 tu() {
  50   while read -r line; do
  51     file="$1"
  52     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  53   done
  54 }
  55 d() {
  56   if $verbose; then
  57     printf "$pre %s\n" "$*"
  58   fi
  59 }
  60 m() {
  61   if $verbose; then
  62     printf "$pre %s\n" "$*"
  63   fi
  64   "$@"
  65 }
  66 x() {
  67   printf "$pre %s\n" "$*"
  68   "$@"
  69 }
  70
  71 mnt() {
  72   dir=$1
  73   if ! mountpoint -q $dir; then
  74     mkdir -p $dir
  75     m mount $dir
  76   fi
  77 }
  78 fstab() {
  79   while read -r start mpoint end; do
  80     l="$start $mpoint $end"
  81     # kill off any lines that duplicate the mount point.
  82     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
  83     tu /etc/fstab <<<"$l"
  84   done
  85 }
  86 pid-check() {
  87   for p in ${pids}; do
  88     for m in ${my_pids[@]}; do
  89       if (( p == m )); then
  90         echo "$0: error: pids to kill includes our pid or a parent. ps output:" >&2
  91         ps -f -p $p
  92         exit 1
  93       fi
  94     done
  95   done
  96 }
  97 kill-dir() {
  98   for sig; do
  99     echo kill-dir $sig
 100     found_pids=false
 101     if pids=$(timeout 4 lsof -t $dir); then
 102       found_pids=true
 103       timeout 4 lsof -w $dir
 104       pid-check
 105       kill -$sig $pids
 106     fi
 107     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 108     # note: -v shows kernel processes, which then doesn't return true when we want
 109     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 110       pid-check
 111       found_pids=true
 112       fuser -$sig -mvk $dir
 113     fi
 114     sleep .5
 115     if ! $found_pids; then
 116       return 0
 117     fi
 118   done
 119   return 1
 120 }
 121 umount-kill() {
 122   dir=$1
 123   if mountpoint -q $dir; then
 124     if m umount -R $dir; then
 125       unmounted+=($dir)
 126     else
 127       if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 128         if $force; then  kill-dir KILL; fi
 129       fi
 130
 131       if m umount -R $dir; then
 132         unmounted+=($dir)
 133       else
 134         echo "$0: failed to umount $dir"
 135         umount_ret=false
 136         ret=1
 137       fi
 138     fi
 139   fi
 140 }
 141
 142 # duplicated in check-subvol
 143 # Reassign $1 var from /dev/dm- to corresponding /dev/mapper/
 144 mapper-dev() {
 145   local mapdev
 146   local -n devref=$1
 147   if [[ $devref == /dev/dm-* ]]; then
 148     for mapdev in /dev/mapper/*; do
 149       if [[ $(readlink -f $mapdev) == "$devref" ]]; then
 150         devref=$mapdev
 151         break
 152       fi
 153     done
 154   fi
 155 }
 156
 157
 158 ##### begin command line parsing ########
 159
 160 # you can remove this if you do not have options which can have args with spaces or empty.
 161
 162 verbose=true
 163 force=false
 164 temp=$(getopt -l help,force,verbose hfv "$@") || usage 1
 165 eval set -- "$temp"
 166 while true; do
 167   case $1 in
 168     -f|--force) force=true ;;
 169     -v|--verbose) verbose=true ;;
 170     -h|--help) usage ;;
 171     --) shift; break ;;
 172     *) echo "$0: unexpected args: $*" >&2 ; usage 1 ;;
 173   esac
 174   shift
 175 done
 176
 177 if (( $# )); then
 178   all_vols=( "$@" )
 179 else
 180   all_vols=(q a o i qd qr)
 181   ar_snaps=(/mnt/root/btrbk/ar.*)
 182   if [[ -e /mnt/root/ar ]] || (( ${#ar_snaps[@]} > 0 )); then
 183     all_vols+=(ar)
 184   fi
 185 fi
 186
 187 ##### end command line parsing ########
 188
 189 ret=0
 190
 191 ##### begin setup fstab for subvols we care about ######
 192
 193 if [[ -e /mnt/root/root2-crypttab ]]; then
 194   tu /etc/crypttab </mnt/root/root2-crypttab
 195   while read -r mapper_dev _; do
 196     if [[ ! -e /dev/mapper/$mapper_dev ]]; then
 197       m cryptdisks_start $mapper_dev
 198     fi
 199   done < <(cat /mnt/root/root2-crypttab)
 200 fi
 201 if [[ -e /mnt/root/root2-fstab ]]; then
 202   tu /etc/fstab </mnt/root/root2-fstab
 203   mnt /mnt/root2
 204   mnt /mnt/boot2
 205 fi
 206
 207 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 208 mapper-dev root_dev
 209 o_dev=$(awk '$2 == "/mnt/o" {print $1}' /etc/mtab)
 210 mapper-dev o_dev
 211
 212
 213 # root2_dev=$(awk '$2 == "/mnt/root2" {print $1}' /etc/mtab)
 214 # mapper-dev root2_dev
 215 # # dont bother with the above for crypt2_dev
 216 # crypt2_dev=$root2_dev
 217
 218
 219 if cryptsetup status $root_dev &>/dev/null; then
 220   crypt_dev=$root_dev
 221 else # if we are in a recovery boot, find the next best crypt device
 222   mopts=,noauto
 223   # todo: I think I had an idea to not setup /o in this case,
 224   # but never finished implementing it
 225   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 226     dev=/dev/mapper/$dev
 227     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 228       crypt_dev=$dev
 229       break
 230     fi
 231   done
 232 fi
 233
 234
 235
 236 # dont tax the cpus of old laptops
 237 if (( $(nproc) > 2)); then
 238   mopts+=,compress=zstd
 239 fi
 240
 241 fstab <<EOF
 242 $crypt_dev  /a  btrfs  noatime,subvol=a$mopts  0 0
 243 EOF
 244
 245
 246 # ssh and probably some other things care about parent directory
 247 # ownership, and ssh doesn\'t allow any group writable parent
 248 # directories, so we are forced to use a directory structure similar
 249 # to home directories
 250 fa=(/mnt/root/btrbk/q.*); f=${fa[0]}
 251 if [[ -e $f ]]; then
 252   fstab <<EOF
 253 $crypt_dev  /q  btrfs  noatime,subvol=q$mopts  0 0
 254 $crypt_dev  /qd  btrfs  noatime,subvol=qd$mopts  0 0
 255 /q/p  /p  none  bind$mopts  0 0
 256 EOF
 257 fi
 258
 259 fa=(/mnt/root/btrbk/qr.*); f=${fa[0]}
 260 if [[ -e $f ]]; then
 261   fstab <<EOF
 262 $crypt_dev  /qr  btrfs  noatime,subvol=qr$mopts  0 0
 263 EOF
 264 fi
 265
 266 # not syncing ar at the moment
 267 # fa=(/mnt/root/btrbk/ar.*); f=${fa[0]}
 268 # if [[ -e $f ]]; then
 269 #   fstab <<EOF
 270 # $crypt_dev  /ar  btrfs  noatime,subvol=ar$mopts  0 0
 271 # EOF
 272 # fi
 273
 274
 275 fa=(/mnt/o/btrbk/o.*); f=${fa[0]}
 276 if [[ -e $f ]]; then
 277   if [[ $o_dev != "$root_dev" ]]; then
 278     # ,compress=zstd regardless of mopts since these are all text files
 279     # and it cuts disk use by about half.
 280     fstab <<EOF
 281 $o_dev  /o  btrfs  noatime,subvol=o${mopts/,compress=zstd/},compress=zstd  0 0
 282 EOF
 283   fi
 284   fstab <<EOF
 285 /o/m  /m  none  bind$mopts  0 0
 286 /o/debbugs  /debbugs  none  bind$mopts  0 0
 287 EOF
 288 fi
 289
 290
 291 ##### end setup fstab for subvols we care about ######
 292
 293 ### begin get pids that this program depends on so we dont kill them
 294 my_pids=($$ $PPID)
 295 loop_limit=30
 296 count=0
 297 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != "${my_pids[-2]}" && $count -lt $loop_limit  ]]; do
 298   count=$((count + 1))
 299   p=$(ps -p ${my_pids[-1]} -o ppid=)
 300   if [[ $p == 0 || ! $p ]]; then
 301     break
 302   fi
 303   my_pids+=($p)
 304 done
 305 ### end get pids that this program depends on so we dont kill them
 306
 307 for vol in ${all_vols[@]}; do
 308   d=/$vol
 309   if ! awk '$3 == "btrfs" {print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 310     continue
 311   fi
 312
 313
 314   ##### begin building up list of bind mounts  ######
 315   binds=() # list of bind mounts
 316   roots=($d)
 317   while true; do
 318     new_roots=()
 319     for r in ${roots[@]}; do
 320       # eg. when r=/q/p, for lines like
 321       # /q/p  /p  none  bind  0 0
 322       # output /p
 323       new_roots+=("$(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+(\S+,|)bind[[:space:],].*#\1#p" /etc/fstab)")
 324     done
 325     (( ${#new_roots} )) || break
 326     binds+=(${new_roots[@]})
 327     # roots is used to recursively find binds of binds if they exist.
 328     roots=( ${new_roots[@]} )
 329   done
 330   ##### end building up list of bind mounts  ######
 331
 332
 333
 334   # if latest is already mounted, make sure binds are mounted and move on
 335   m check-subvol-stale $d
 336   # populated by check-subvol-stale if stale
 337   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 338     mnt $d
 339     did=$(stat -c%d $d)
 340     for b in ${binds[@]}; do
 341       if mountpoint -q $b; then
 342         bid=$(stat -c%d $b)
 343         if [[ $did != "$bid" ]]; then
 344           umount-kill $b
 345         fi
 346       fi
 347       mnt $b
 348     done
 349     continue
 350   fi
 351
 352
 353   ##### begin checking for loopback mounts ####
 354   found_loop=false
 355   for l in $(losetup -ln|awk '{print $6}'); do
 356     for dir in $d ${binds[@]}; do
 357       if [[ $l == $dir* ]]; then
 358         echo "$0: found loopback mount $l. giving up on unmounting $dir"
 359         ret=1
 360         found_loop=true
 361         break
 362       fi
 363     done
 364     if $found_loop; then
 365       break
 366     fi
 367   done
 368   if $found_loop; then
 369     continue
 370   fi
 371   ##### end end checking loopback mounts ####
 372
 373
 374   ## not using arbtt at the moment
 375   # if [[ $vol == q ]]; then
 376   #   ## allow to fail, user might not be logged in
 377   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user stop arbtt ||:
 378   # fi
 379   umount_ret=true
 380   unmounted=()
 381   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 382     umount-kill $dir
 383   done
 384
 385   # if we unmounted some but not all, restore them and move on
 386   if ! $umount_ret; then
 387     for dir in ${unmounted[@]}; do
 388       mnt $dir
 389     done
 390     continue
 391   fi
 392
 393   #### begin dealing with leaf vols ####
 394
 395   ### begin getting root_dir
 396   ### this is duplicated in check-subvol-stale
 397
 398   dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab /etc/mtab|head -n1)
 399   d dev=$dev
 400   # note, we need $dev because $d might not be mounted, and we do this loop
 401   # because the device in fstab for the rootfs can be different.
 402   for devx in $(btrfs fil show $dev| sed -rn 's#.*path (\S+)$#\1#p'); do
 403     if [[ $devx == dm-* ]]; then
 404       devx=/dev/$devx
 405       mapper-dev devx
 406     fi
 407     d devx=$devx
 408     root_dir=$(sed -rn "s,^\s*$devx\s+(\S+).*\bsubvolid=[05]\b.*,\1,p" /etc/mtab /etc/fstab|head -n1)
 409     if [[ $root_dir ]]; then
 410       d root_dir=$root_dir
 411       break
 412     fi
 413   done
 414   if [[ ! $root_dir ]]; then
 415     echo "$0: error could not find root subvol mount for $dev" >&2
 416     exit 1
 417   fi
 418   ### end getting root_dir
 419
 420   cd $root_dir
 421   if [[ -e $vol  ]]; then
 422     if [[ $vol == qd ]]; then
 423       m btrfs sub del qd
 424     else
 425       leaf=$vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 426       m mv $vol $leaf
 427       m btrfs property set -ts $leaf ro true
 428
 429       ### begin check if leaf is different, delete it if not ###
 430       parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
 431       bsubs=(btrbk/$vol.*)
 432       bsub= # base subvolume
 433       # go in reverse order as its more likely to be at the end
 434       for ((i=${#bsubs[@]}-1; i>=0; i--)); do
 435         if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
 436           bsub=${bsubs[i]}
 437           break
 438         fi
 439       done
 440       if [[ $bsub ]]; then
 441         # in testing, same subvol is 136 bytes. allow some overhead. 32 happens sometimes under systemd.
 442         # $ errno 32
 443         # EPIPE 32 Broken pipe
 444         lines=$(btrfs send --no-data -p $bsub $leaf | btrfs receive --dump | head -n 100 | wc -l || [[ $? == 141 || ${PIPESTATUS[0]} == 32 ]])
 445         if [[ $lines == 0 ]]; then
 446           # example output of no differences:
 447           # snapshot        ./qrtest                        uuid=c41ff6b7-0527-f34d-95ac-190eecf54ff5 transid=2239 parent_uuid=64949e1b-4a3e-3945-9a8e-cd7b7c15d7d6 parent_transid=2239
 448           echo suspected identical: $bsub $leaf
 449           x btrfs sub del $leaf
 450         fi
 451       fi
 452       ### end check if leaf is different, delete it if not ###
 453
 454       ## begin expire leaf vols ##
 455       leaf_vols=($vol.leaf.*)
 456       count=${#leaf_vols[@]}
 457       leaf_limit_time=$(( EPOCHSECONDS - 60*60*24*60 )) # 60 days
 458       leaf_new_limit_time=$(( EPOCHSECONDS - 60*60*24 * 5 )) # 5 days this
 459       # goes backwards from oldest. leaf_new_limit_time is a safety
 460       # measure to ensure we don't delete very recent leafs.
 461       for leaf in ${leaf_vols[@]}; do
 462         leaf_time=$(date -d ${leaf#"$vol".leaf.} +%s)
 463         if (( leaf_limit_time > leaf_time || ( leaf_new_limit_time > leaf_time && count > 30 ) )); then
 464           x btrfs sub del $leaf
 465         fi
 466         count=$((count-1))
 467       done
 468     fi
 469     ## end expire leaf vols ##
 470   fi
 471   #### end dealing with leaf vols ####
 472
 473   # Note, we make a few assumptions in this script, like
 474   # $d was not a different subvol id than $vol, and
 475   # things otherwise didn't get mounted very strangely.
 476   m btrfs sub snapshot $fresh_snap $vol
 477   for dir in $d ${binds[@]}; do
 478     m mnt $dir
 479   done
 480
 481   ## arbtt disabled for now
 482   # if [[ $vol == q ]]; then
 483   #   # maybe this will fail if X is not running
 484   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user start arbtt ||:
 485   # fi
 486
 487   stale_dir=/nocow/btrfs-stale
 488   rm -f $stale_dir/$d
 489 done
 490
 491
 492
 493 for dir in /mnt/r7/amy/{root/root,boot/boot}_ubuntubionic /mnt/{root2/root,boot2/boot}_ubuntubionic; do
 494   vol=${dir##*/}
 495   root_dir=${dir%/*}
 496   if [[ ! -d $root_dir ]]; then
 497     # this only exists on host kd currently
 498     continue
 499   fi
 500   # if latest is already mounted, make sure binds are mounted and move on
 501   m check-subvol-stale -p $dir
 502   # populated by check-subvol-stale if stale
 503   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 504     continue
 505   fi
 506   if [[ -d $dir ]]; then
 507     if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 508       if $force; then  kill-dir KILL; fi
 509     fi
 510     m btrfs sub del $dir
 511   fi
 512   m btrfs sub snapshot $fresh_snap $dir
 513   rm -f /nocow/btrfs-stale/$vol
 514 done
 515
 516 if (( ret >= 1 )); then
 517   echo "$0: exit status $ret. see error above"
 518 fi
 519 exit $ret
 520
 521