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 this_file="$(readlink -f -- "${BASH_SOURCE[0]}")"
  17 readonly this_file
  18 cd /
  19 [[ $EUID == 0 ]] || exec sudo -E "$this_file" "$@"
  20
  21 source /usr/local/lib/err
  22
  23 usage() {
  24   cat <<EOF
  25 Usage: ${0##*/} [OPTIONS] [SUBVOLUMES]
  26
  27 -h|--help  Print help and exit.
  28 -f|--force  Use kill -9 to try fixing unmount errors
  29 -v|--verbose  Be more verbose
  30
  31
  32 Note: In git this is not not executable because it's meant to be installed
  33 using ./install-my-scripts
  34
  35 Note: Uses util-linux getopt option parsing: spaces between args and
  36 options, short options can be combined, options before args.
  37 EOF
  38   exit $1
  39 }
  40
  41 pre="mount-latest-subvol:${SSH_CLIENT:+ $HOSTNAME:}"
  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 $verbose; then
  51     printf "$pre %s\n" "$*"
  52   fi
  53 }
  54 m() {
  55   if $verbose; then
  56     printf "$pre %s\n" "$*"
  57   fi
  58   "$@"
  59 }
  60 x() {
  61   printf "$pre %s\n" "$*"
  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 if (( $# )); then
 172   all_vols=( "$@" )
 173 else
 174   all_vols=(q a o i ar qd qr)
 175 fi
 176
 177 ##### end command line parsing ########
 178
 179 ret=0
 180
 181 ##### begin setup fstab for subvols we care about ######
 182
 183 if [[ -e /mnt/root/root2-crypttab ]]; then
 184   tu /etc/crypttab </mnt/root/root2-crypttab
 185   while read -r mapper_dev _; do
 186     if [[ ! -e /dev/mapper/$mapper_dev ]]; then
 187       m cryptdisks_start $mapper_dev
 188     fi
 189   done < <(cat /mnt/root/root2-crypttab)
 190 fi
 191 if [[ -e /mnt/root/root2-fstab ]]; then
 192   tu /etc/fstab </mnt/root/root2-fstab
 193   mnt /mnt/root2
 194   mnt /mnt/boot2
 195 fi
 196
 197 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 198 mapper-dev root_dev
 199 o_dev=$(awk '$2 == "/mnt/o" {print $1}' /etc/mtab)
 200 mapper-dev o_dev
 201
 202
 203 # root2_dev=$(awk '$2 == "/mnt/root2" {print $1}' /etc/mtab)
 204 # mapper-dev root2_dev
 205 # # dont bother with the above for crypt2_dev
 206 # crypt2_dev=$root2_dev
 207
 208
 209 if cryptsetup status $root_dev &>/dev/null; then
 210   crypt_dev=$root_dev
 211 else # if we are in a recovery boot, find the next best crypt device
 212   mopts=,noauto
 213   # todo: I think I had an idea to not setup /o in this case,
 214   # but never finished implementing it
 215   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 216     dev=/dev/mapper/$dev
 217     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 218       crypt_dev=$dev
 219       break
 220     fi
 221   done
 222 fi
 223
 224
 225
 226 # dont tax the cpus of old laptops
 227 if (( $(nproc) > 2)); then
 228   mopts+=,compress=zstd
 229 fi
 230
 231 fstab <<EOF
 232 $crypt_dev  /a  btrfs  noatime,subvol=a$mopts  0 0
 233 EOF
 234
 235 shopt -s nullglob
 236
 237 # ssh and probably some other things care about parent directory
 238 # ownership, and ssh doesn\'t allow any group writable parent
 239 # directories, so we are forced to use a directory structure similar
 240 # to home directories
 241 fa=(/mnt/root/btrbk/q.*); f=${fa[0]}
 242 if [[ -e $f ]]; then
 243   fstab <<EOF
 244 $crypt_dev  /q  btrfs  noatime,subvol=q,gid=1000$mopts  0 0
 245 $crypt_dev  /qd  btrfs  noatime,subvol=qd,gid=1000$mopts  0 0
 246 /q/p  /p  none  bind$mopts  0 0
 247 EOF
 248 fi
 249
 250 fa=(/mnt/root/btrbk/qr.*); f=${fa[0]}
 251 if [[ -e $f ]]; then
 252   fstab <<EOF
 253 $crypt_dev  /qr  btrfs  noatime,subvol=qr$mopts  0 0
 254 EOF
 255 fi
 256
 257 fa=(/mnt/root/btrbk/ar.*); f=${fa[0]}
 258 if [[ -e $f ]]; then
 259   fstab <<EOF
 260 $crypt_dev  /ar  btrfs  noatime,subvol=ar,uid=1000,gid=1000$mopts  0 0
 261 EOF
 262 fi
 263
 264
 265 fa=(/mnt/o/btrbk/o.*); f=${fa[0]}
 266 if [[ -e $f ]]; then
 267   if [[ $o_dev != "$root_dev" ]]; then
 268     fstab <<EOF
 269 $o_dev  /o  btrfs  noatime,subvol=o$mopts  0 0
 270 EOF
 271   fi
 272   fstab <<EOF
 273 /o/m  /m  none  bind$mopts  0 0
 274 /o/debbugs  /debbugs  none  bind$mopts  0 0
 275 EOF
 276 fi
 277
 278
 279 ##### end setup fstab for subvols we care about ######
 280
 281 ### begin get pids that this program depends on so we dont kill them
 282 my_pids=($$ $PPID)
 283 loop_limit=30
 284 count=0
 285 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != "${my_pids[-2]}" && $count -lt $loop_limit  ]]; do
 286   count=$((count + 1))
 287   p=$(ps -p ${my_pids[-1]} -o ppid=)
 288   if [[ $p == 0 || ! $p ]]; then
 289     break
 290   fi
 291   my_pids+=($p)
 292 done
 293 ### end get pids that this program depends on so we dont kill them
 294
 295 for vol in ${all_vols[@]}; do
 296   d=/$vol
 297   if ! awk '$3 == "btrfs" {print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 298     continue
 299   fi
 300
 301
 302   ##### begin building up list of bind mounts  ######
 303   binds=() # list of bind mounts
 304   roots=($d)
 305   while true; do
 306     new_roots=()
 307     for r in ${roots[@]}; do
 308       # eg. when r=/q/p, for lines like
 309       # /q/p  /p  none  bind  0 0
 310       # output /p
 311       new_roots+=("$(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+(\S+,|)bind[[:space:],].*#\1#p" /etc/fstab)")
 312     done
 313     (( ${#new_roots} )) || break
 314     binds+=(${new_roots[@]})
 315     # roots is used to recursively find binds of binds if they exist.
 316     roots=( ${new_roots[@]} )
 317   done
 318   ##### end building up list of bind mounts  ######
 319
 320
 321
 322   # if latest is already mounted, make sure binds are mounted and move on
 323   m check-subvol-stale $d
 324   # populated by check-subvol-stale if stale
 325   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 326     mnt $d
 327     did=$(stat -c%d $d)
 328     for b in ${binds[@]}; do
 329       if mountpoint -q $b; then
 330         bid=$(stat -c%d $b)
 331         if [[ $did != "$bid" ]]; then
 332           umount-kill $b
 333         fi
 334       fi
 335       mnt $b
 336     done
 337     continue
 338   fi
 339
 340
 341   ##### begin checking for loopback mounts ####
 342   found_loop=false
 343   for l in $(losetup -ln|awk '{print $6}'); do
 344     for dir in $d ${binds[@]}; do
 345       if [[ $l == $dir* ]]; then
 346         echo "$0: found loopback mount $l. giving up on unmounting $dir"
 347         ret=1
 348         found_loop=true
 349         break
 350       fi
 351     done
 352     if $found_loop; then
 353       break
 354     fi
 355   done
 356   if $found_loop; then
 357     continue
 358   fi
 359   ##### end end checking loopback mounts ####
 360
 361
 362   ## not using arbtt at the moment
 363   # if [[ $vol == q ]]; then
 364   #   ## allow to fail, user might not be logged in
 365   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user stop arbtt ||:
 366   # fi
 367   umount_ret=true
 368   unmounted=()
 369   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 370     umount-kill $dir
 371   done
 372
 373   # if we unmounted some but not all, restore them and move on
 374   if ! $umount_ret; then
 375     for dir in ${unmounted[@]}; do
 376       mnt $dir
 377     done
 378     continue
 379   fi
 380
 381   #### begin dealing with leaf vols ####
 382
 383   ### begin getting root_dir
 384   ### this is duplicated in check-subvol-stale
 385
 386   dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab /etc/mtab|head -n1)
 387   d dev=$dev
 388   # note, we need $dev because $d might not be mounted, and we do this loop
 389   # because the device in fstab for the rootfs can be different.
 390   for devx in $(btrfs fil show $dev| sed -rn 's#.*path (\S+)$#\1#p'); do
 391     if [[ $devx == dm-* ]]; then
 392       devx=/dev/$devx
 393       mapper-dev devx
 394     fi
 395     d devx=$devx
 396     root_dir=$(sed -rn "s,^\s*$devx\s+(\S+).*\bsubvolid=[05]\b.*,\1,p" /etc/mtab /etc/fstab|head -n1)
 397     if [[ $root_dir ]]; then
 398       d root_dir=$root_dir
 399       break
 400     fi
 401   done
 402   if [[ ! $root_dir ]]; then
 403     echo "$0: error could not find root subvol mount for $dev" >&2
 404     exit 1
 405   fi
 406   ### end getting root_dir
 407
 408   cd $root_dir
 409   if [[ -e $vol  ]]; then
 410     if [[ $vol == qd ]]; then
 411       m btrfs sub del qd
 412     else
 413       leaf=$vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 414       m mv $vol $leaf
 415       m btrfs property set -ts $leaf ro true
 416
 417       ### begin check if leaf is different, delete it if not ###
 418       parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
 419       bsubs=(btrbk/$vol.*)
 420       bsub= # base subvolume
 421       # go in reverse order as its more likely to be at the end
 422       for ((i=${#bsubs[@]}-1; i>=0; i--)); do
 423         if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
 424           bsub=${bsubs[i]}
 425           break
 426         fi
 427       done
 428       if [[ $bsub ]]; then
 429         # in testing, same subvol is 136 bytes. allow some overhead. 32 happens sometimes under systemd.
 430         # $ errno 32
 431         # EPIPE 32 Broken pipe
 432         lines=$(btrfs send --no-data -p $bsub $leaf | btrfs receive --dump | head -n 100 | wc -l || [[ $? == 141 || ${PIPESTATUS[0]} == 32 ]])
 433         if [[ $lines == 0 ]]; then
 434           # example output of no differences:
 435           # snapshot        ./qrtest                        uuid=c41ff6b7-0527-f34d-95ac-190eecf54ff5 transid=2239 parent_uuid=64949e1b-4a3e-3945-9a8e-cd7b7c15d7d6 parent_transid=2239
 436           echo suspected identical: $bsub $leaf
 437           x btrfs sub del $leaf
 438         fi
 439       fi
 440       ### end check if leaf is different, delete it if not ###
 441
 442       ## begin expire leaf vols ##
 443       leaf_vols=($vol.leaf.*)
 444       count=${#leaf_vols[@]}
 445       leaf_limit_time=$(( EPOCHSECONDS - 60*60*24*60 )) # 60 days
 446       leaf_new_limit_time=$(( EPOCHSECONDS - 60*60*24 * 5 )) # 5 days this
 447       # goes backwards from oldest. leaf_new_limit_time is a safety
 448       # measure to ensure we don't delete very recent leafs.
 449       for leaf in ${leaf_vols[@]}; do
 450         leaf_time=$(date -d ${leaf#"$vol".leaf.} +%s)
 451         if (( leaf_limit_time > leaf_time || ( leaf_new_limit_time > leaf_time && count > 30 ) )); then
 452           x btrfs sub del $leaf
 453         fi
 454         count=$((count-1))
 455       done
 456     fi
 457     ## end expire leaf vols ##
 458   fi
 459   #### end dealing with leaf vols ####
 460
 461   # Note, we make a few assumptions in this script, like
 462   # $d was not a different subvol id than $vol, and
 463   # things otherwise didn't get mounted very strangely.
 464   m btrfs sub snapshot $fresh_snap $vol
 465   for dir in $d ${binds[@]}; do
 466     m mnt $dir
 467   done
 468
 469   ## arbtt disabled for now
 470   # if [[ $vol == q ]]; then
 471   #   # maybe this will fail if X is not running
 472   #   x sudo -u $(id -nu 1000) XDG_RUNTIME_DIR=/run/user/1000 systemctl --user start arbtt ||:
 473   # fi
 474
 475   stale_dir=/nocow/btrfs-stale
 476   rm -f $stale_dir/$d
 477 done
 478
 479
 480
 481 for dir in /mnt/r7/amy/{root/root,boot/boot}_ubuntubionic /mnt/{root2/root,boot2/boot}_ubuntubionic; do
 482   vol=${dir##*/}
 483   root_dir=${dir%/*}
 484   if [[ ! -d $root_dir ]]; then
 485     # this only exists on host kd currently
 486     continue
 487   fi
 488   # if latest is already mounted, make sure binds are mounted and move on
 489   m check-subvol-stale -p $dir
 490   # populated by check-subvol-stale if stale
 491   if ! fresh_snap=$(cat /nocow/btrfs-stale/$vol 2>/dev/null); then
 492     continue
 493   fi
 494   if [[ -d $dir ]]; then
 495     if ! kill-dir TERM TERM TERM INT INT HUP HUP TERM TERM TERM INT INT HUP HUP; then
 496       if $force; then  kill-dir KILL; fi
 497     fi
 498     m btrfs sub del $dir
 499   fi
 500   m btrfs sub snapshot $fresh_snap $dir
 501   rm -f /nocow/btrfs-stale/$vol
 502 done
 503
 504 if (( ret >= 1 )); then
 505   echo "$0: exit status $ret. see error above"
 506 fi
 507 exit $ret
 508
 509