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