iankelling.org Git - distro-setup/blob - check-subvol-stale

   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: $0 SUBVOL_MOUNTPOINT...
  17 # if latest subvols $@ are not mounted, exit 1, print message, and touch /nocow/btrfs-stale/$subvol
  18
  19 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
  20
  21 set -eE -o pipefail
  22 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  23
  24 shopt -s nullglob
  25
  26 if [[ ! $@ ]]; then
  27     echo "$0: error: expected mountpoint argument"
  28 fi
  29
  30 ret=0
  31 for d; do
  32     vol=${d##*/}
  33     cd /mnt/root/btrbk
  34     snaps=($vol.20*)
  35     if [[ ! $snaps ]]; then
  36         # no snapshots yet
  37         continue
  38     fi
  39     # when a btrbk bugfix makes it into the distro,
  40     # we might replace this with btrbk list latest /mnt/root/$vol | ...
  41     # note: this is duplicated in mount-latest-subvol
  42     last_snap=$(
  43         for f in ${snaps[@]}; do
  44             printf "%s %s\n" $(date -d $(sed -r  's/(.{4})(..)(.{5})(..)(.*)/\1-\2-\3:\4:\5/' <<<${f#$vol.}) +%s) $f
  45         done | sort -r | head -n 1 | awk '{print $2}'
  46              )
  47     if [[ ! $last_snap ]]; then
  48         echo "$d stale"
  49         ret=1
  50         continue
  51     fi
  52     stale=true
  53     if btrfs sub show $d 2>/dev/null | sed '0,/^\t*Snapshot(s):/d;s/^\s*//' | \
  54             grep -xF btrbk/$last_snap &>/dev/null; then
  55         stale=false
  56     else
  57         last_uuid=$(btrfs sub show $last_snap| awk '$1 == "UUID:" {print $2}')
  58         if btrfs sub show $d| grep "^\s*Parent UUID:\s*$last_uuid$" &>/dev/null; then
  59             stale=false
  60         fi
  61     fi
  62     stale_dir=/nocow/btrfs-stale
  63     stale_file=$stale_dir/$vol
  64     if $stale; then
  65         mkdir -p $stale_dir
  66         printf "%s\n" $last_snap > $stale_file
  67         echo "$d stale"
  68         ret=1
  69         continue
  70     else
  71         rm -f $stale_file
  72     fi
  73 done
  74 exit $ret
  75