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