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 # usage: mount-latest-subvol
  17 #
  18 # Note, at source location, intentionally not executable, run and read
  19 # install-my-scripts.
  20
  21 cd /
  22 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
  23
  24 errcatch() {
  25   set -E; shopt -s extdebug
  26   _err-trap() {
  27     err=$?
  28     exec >&2
  29     set +x
  30     echo "${BASH_SOURCE[1]}:${BASH_LINENO[0]}:in \`$BASH_COMMAND' returned $err"
  31     bash-trace 2
  32     echo "$0: exiting with code $err"
  33     exit $err
  34   }
  35   trap _err-trap ERR
  36   set -o pipefail
  37 }
  38 bash-trace() {
  39   local -i argc_index=0 frame i start=${1:-1} max_indent=8 indent
  40   local source
  41   local extdebug=false
  42   if [[ $(shopt -p extdebug) == *-s* ]]; then
  43     extdebug=true
  44   fi
  45
  46   for ((frame=0; frame < ${#FUNCNAME[@]}-1; frame++)); do
  47     argc=${BASH_ARGC[frame]}
  48     argc_index+=$argc
  49     ((frame < start)) && continue
  50     if (( ${#BASH_SOURCE[@]} > 1 )); then
  51       source="${BASH_SOURCE[frame+1]}:${BASH_LINENO[frame]}:"
  52     fi
  53     indent=$((frame-start+1))
  54     indent=$((indent < max_indent ? indent : max_indent))
  55     printf "%${indent}s↳%sin \`%s" '' "$source" "${FUNCNAME[frame]}"
  56     if $extdebug; then
  57       for ((i=argc_index-1; i >= argc_index-argc; i--)); do
  58         printf " %s" "${BASH_ARGV[i]}"
  59       done
  60     fi
  61     echo \'
  62   done
  63 }
  64 errcatch
  65
  66 tu() {
  67   while read -r line; do
  68     file="$1"
  69     grep -xFq "$line" "$file" || tee -a "$file"<<<"$line"
  70   done
  71 }
  72 e() { printf "%s\n" "$*"; "$@"; }
  73 mnt() {
  74   dir=$1
  75   if ! mountpoint $dir &>/dev/null; then
  76     mkdir -p $dir
  77     e mount $dir
  78   fi
  79 }
  80 fstab() {
  81   while read -r start mpoint end; do
  82     l="$start $mpoint $end"
  83     # kill off any lines that duplicate the mount point.
  84     sed --follow-symlinks -ri "\%$l%b;\%^\s*\S+\s+$mpoint\s%d" /etc/fstab
  85     tu /etc/fstab <<<"$l"
  86   done
  87 }
  88 pid-check() {
  89   for p in ${pids}; do
  90     for m in ${my_pids[@]}; do
  91       if (( p == m )); then
  92         echo "$0: error: pids to kill includes our pid or a parent. ps output:" >&2
  93         ps -f -p $p
  94         exit 1
  95       fi
  96     done
  97   done
  98 }
  99 kill-dir() {
 100   for sig; do
 101     echo kill-dir $sig
 102     found_pids=false
 103     if pids=$(timeout 4 lsof -t $dir); then
 104       found_pids=true
 105       timeout 4 lsof -w $dir
 106       pid-check
 107       kill -$sig $pids
 108     fi
 109     # fuser will find open sockets that lsof won't, for example from gpg-agent.
 110     # note: -v shows kernel processes, which then doesn't return true when we want
 111     if pids=$(timeout 4 fuser -m $dir 2>/dev/null); then
 112       pid-check
 113       found_pids=true
 114       fuser -$sig -mvk $dir
 115     fi
 116     sleep .5
 117     if ! $found_pids; then
 118       return 0
 119     fi
 120   done
 121   return 1
 122 }
 123
 124 force=false
 125 if [[ $1 == -f ]]; then
 126   force=true
 127 fi
 128
 129 ret=0
 130
 131 ##### begin setup fstab for subvols we care about ######
 132 root_dev=$(awk '$2 == "/" {print $1}' /etc/mtab)
 133
 134
 135 if cryptsetup status $root_dev &>/dev/null; then
 136   crypt_dev=$root_dev
 137 else # if we are in a recovery boot, find the next best crypt device
 138   noauto=,noauto
 139   for dev in $(dmsetup ls --target crypt | awk '{print $1}'); do
 140     dev=/dev/mapper/$dev
 141     if awk '{print $1}' /etc/mtab | grep -Fx $dev &>/dev/null; then
 142       crypt_dev=$dev
 143       break
 144     fi
 145   done
 146 fi
 147
 148
 149 fstab <<EOF
 150 $crypt_dev  /a  btrfs  noatime,subvol=a$noauto  0 0
 151 EOF
 152
 153 shopt -s nullglob
 154
 155 # ssh and probably some other things care about parent directory
 156 # ownership, and ssh doesn\'t allow any group writable parent
 157 # directories, so we are forced to use a directory structure similar
 158 # to home directories
 159 f=(/mnt/root/btrbk/q.*)
 160 if [[ -e $f ]]; then
 161   fstab <<EOF
 162 $crypt_dev  /q  btrfs  noatime,subvol=q,gid=1000$noauto  0 0
 163 /q/p  /p  none  bind$noauto  0 0
 164 EOF
 165 fi
 166
 167 f=(/mnt/root/btrbk/o.*)
 168 if [[ -e $f ]]; then
 169   fstab <<EOF
 170 $crypt_dev  /o  btrfs  noatime,subvol=o$noauto  0 0
 171 /o/m  /m  none  bind$noauto  0 0
 172 EOF
 173 fi
 174
 175 if [[ $HOSTNAME == frodo ]]; then
 176   fstab <<EOF
 177 $crypt_dev  /i  btrfs  noatime,subvol=i$noauto  0 0
 178 EOF
 179 fi
 180 ##### end setup fstab for subvols we care about ######
 181
 182 # get pids that this program depends on so we dont kill them
 183 my_pids=($$ $PPID)
 184 loop_limit=30
 185 count=0
 186 while [[ ${my_pids[-1]} != 1 && ${my_pids[-1]} != ${my_pids[-2]} && $count -lt $loop_limit  ]]; do
 187   count=$((count + 1))
 188   p=$(ps -p ${my_pids[-1]} -o ppid=)
 189   if [[ $p == 0 || ! $p ]]; then
 190     break
 191   fi
 192   my_pids+=($p)
 193 done
 194
 195
 196 for vol in q a o i; do
 197   d=/$vol
 198   if ! awk '{print $2}' /etc/fstab | grep -xF $d &>/dev/null; then
 199     continue
 200   fi
 201
 202
 203   ##### begin building up list of bind mounts  ######
 204   binds=() # list of bind mounts
 205   roots=($d) # list of bind mounts, plus the original mount
 206   while true; do
 207     new_roots=()
 208     for r in ${roots[@]}; do
 209       # eg. when r=/q/p, for lines like
 210       # /q/p  /p  none  bind  0 0
 211       # output /p
 212       new_roots+=($(sed -rn "s#^$r/\S+\s+(\S+)\s+none\s+bind\s.*#\1#p" /etc/fstab))
 213     done
 214     (( ${#new_roots} )) || break
 215     binds+=(${new_roots[@]})
 216     roots=( ${new_roots[@]} )
 217   done
 218   ##### end building up list of bind mounts  ######
 219
 220
 221   # if latest is already mounted, make sure binds are mounted and move on
 222   if e check-subvol-stale $d; then
 223     mnt $d
 224     for b in ${binds[@]}; do
 225       mnt $b
 226     done
 227     continue
 228   fi
 229
 230   # populated by check-subvol-stale
 231   fresh_snap=$(</nocow/btrfs-stale/$vol)
 232   if [[ ! $fresh_snap ]]; then
 233     echo "$0: error. empty fresh_snap var"
 234     ret=1
 235     continue
 236   fi
 237
 238   umount_ret=true
 239   unmounted=()
 240   for dir in $(echo $d ${binds[*]}\ |tac -s\ ); do
 241     if mountpoint $dir; then
 242       if e umount -R $dir; then
 243         unmounted+=($dir)
 244       else
 245         if ! kill-dir TERM TERM TERM INT INT HUP HUP; then
 246           if $force; then  kill-dir KILL; fi
 247         fi
 248
 249         if e umount -R $dir; then
 250           unmounted+=($dir)
 251         else
 252           echo "$0: failed to umount $dir"
 253           umount_ret=false
 254           ret=1
 255           continue
 256         fi
 257       fi
 258     fi
 259   done
 260
 261   if ! $umount_ret; then
 262     for dir in ${unmounted[@]}; do
 263       mnt $dir
 264     done
 265     continue
 266   fi
 267
 268   # todo: decipher /mnt/root, like we do in check-subvol-stale
 269   cd /mnt/root
 270   if [[ -e $vol ]]; then
 271     e mv $vol $vol.leaf.$(date +%Y-%m-%dT%H:%M:%S%z)
 272     leaf_vols=($vol.leaf.*)
 273     for leaf in ${leaf_vols[@]}; do
 274       leaf_secs=$(date -d ${leaf#$vol.leaf.} +%s)
 275       if (( $(date +%s) - 60*60*24*60 > leaf_secs )); then # 60 days
 276         e btrfs sub del $leaf
 277       fi
 278     done
 279   fi
 280   # Note, we make a few assumptions in this script, like
 281   # $d was not a different subvol id than $vol, and
 282   # things otherwise didn't get mounted very strangely.
 283   e btrfs sub snapshot $fresh_snap $vol
 284   for dir in $d ${binds[@]}; do
 285     e mnt $dir
 286   done
 287   stale_dir=/nocow/btrfs-stale
 288   rm -f $stale_dir/$d
 289 done
 290
 291 ### disabled
 292 if [[ $HOSTNAME == kdxxxxxxxxx ]]; then
 293   # partitioned it with fai partitioner outside of fai,
 294   # because it\'s worth it to have 1% space reserved for boot and
 295   # swap partitions in case I ever want to boot off those drives.
 296   # as root:
 297   # . /a/bin/fai/fai-wrapper
 298   # eval-fai-classfile /a/bin/fai/fai/config/class/51-multi-boot
 299   # fai-setclass ROTATIONAL
 300   # export LUKS_DIR=/q/root/luks/
 301   # # because the partition nums existed already
 302   # fai-setclass REPARTITION
 303   # /a/bin/fai/fai/config/hooks/partition.DEFAULT
 304
 305   devs=(
 306     ata-TOSHIBA_MD04ACA500_84REK6NTFS9A-part1
 307     ata-TOSHIBA_MD04ACA500_84R2K773FS9A-part1
 308     ata-TOSHIBA_MD04ACA500_8471K430FS9A-part1
 309     ata-TOSHIBA_MD04ACA500_8481K493FS9A-part1
 310   )
 311   first=true
 312   for dev in ${devs[@]}; do
 313     if $first; then
 314       first=false
 315       tu /etc/fstab <<EOF
 316 /dev/mapper/crypt_dev_$dev /i btrfs  noatime,subvol=i,noauto  0 0
 317 /dev/mapper/crypt_dev_$dev /mnt/iroot btrfs  noatime,subvolid=0,noauto  0 0
 318 EOF
 319     fi
 320     tu /etc/crypttab <<EOF
 321 crypt_dev_$dev  /dev/disk/by-id/$dev  /q/root/luks/host-kd  discard,luks
 322 EOF
 323     if [[ ! -e /dev/mapper/crypt_dev_$dev ]]; then
 324       cryptdisks_start crypt_dev_$dev
 325     fi
 326   done
 327   # note, could do an else here and have some kind of mount for /i
 328   # on other hosts.
 329 fi
 330
 331 exit $ret