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