--- /dev/null
+#!/bin/bash
+
+
+[[ $EUID == 0 ]] || exec sudo -E "${BASH_SOURCE[0]}" "$@"
+
+set -e; . /usr/local/lib/err; set +e
+
+# inspired from
+# https://github.com/kdave/btrfsmaintenance
+
+if [[ $INVOCATION_ID ]]; then
+ err-cleanup() {
+ exim -odf -i root <<EOF
+From: root@$(hostname -f)
+To: root@$(hostname -f)
+Subject: btrfsmaint automatically exited on command error
+
+journalctl -u btrfsmaint -n 50:
+$(journalctl -u btrfsmaint -n 50)
+EOF
+ }
+fi
+
+dusage="5 10"
+musage="5"
+
+e() {
+ echo "btrfsmaint: $*"
+ if ! $dryrun; then
+ "$@"
+ fi
+}
+
+check-idle() {
+ type -p xscreensaver-command &>/dev/null || return 0
+ export DISPLAY=:0
+ locked=false
+ if lock_info=$(xscreensaver-command -time); then
+ if [[ $lock_info != *non-blanked* ]]; then
+ locked=true
+ fi
+ else
+ locked=true
+ fi
+}
+
+usage() {
+ cat <<EOF
+Usage: ${0##*/} [OPTIONS]
+Do btrfs maintence or stop if we have X and xprintidle shows a user
+
+Normally, no options are needed.
+
+--check Only check if an existing maintence should be cancelled due to
+ nonidle user and run in a loop every 20 seconds for 10
+ minutes.
+
+--dryrun Just print out what we would do.
+
+--force Run regardless of user idle status on all disks and do scrub
+ regardless of when it was last run.
+--no-stats Avoid checking error statistics. Use this to avoid a rare race
+ condition when running --check concurrently with normal run.
+
+
+-h|--help Show help
+
+Note: Uses util-linux getopt option parsing: spaces between args and
+options, short options can be combined, options before args.
+EOF
+ exit $1
+}
+
+##### begin command line parsing ########
+
+# ensure we can handle args with spaces or empty.
+ret=0; getopt -T || ret=$?
+[[ $ret == 4 ]] || { echo "Install util-linux for enhanced getopt" >&2; exit 1; }
+
+check=false
+dryrun=false
+force=false
+stats=true
+
+temp=$(getopt -l help,check,dryrun,force,no-stats h "$@") || usage 1
+eval set -- "$temp"
+while true; do
+ case $1 in
+ --check) check=true ;;
+ --dryrun) dryrun=true ;;
+ --force) force=true ;;
+ --no-stats) stats=false ;;
+ -h|--help) usage ;;
+ --) shift; break ;;
+ *) echo "$0: unexpected args: $*" >&2 ; usage 1 ;;
+ esac
+ shift
+done
+readonly check dryrun force stats
+##### end command line parsing ########
+
+
+main() {
+ if ! $force; then
+ check-idle
+ if ! $check; then
+ min=0
+ max_min=300
+ # When the cron kicks in, we may not be idle (physically sleeping) yet, so
+ # wait.
+ while ! $locked && (( min < max_min )); do
+ min=$(( min + 1 ))
+ sleep 60
+ check-idle
+ done
+ # If we've waited a really long time for idle, just give up.
+ if (( min == max_min )); then
+ return
+ fi
+ fi
+ fi
+
+
+ fnd="findmnt --types btrfs --noheading"
+ for x in $($fnd --output "SOURCE" --nofsroot | sort -u); do
+ mnt=$($fnd --output "TARGET" --first-only --source $x)
+ [[ $mnt ]] || continue
+
+ #### begin look for diff in stats, eg: increasing error count ####
+ if $stats; then
+ tmp=$(mktemp)
+ # ${mnt%/} so that if mnt is / we avoid making a buggy looking path
+ stats_path=${mnt%/}/btrfs-dev-stats
+ if [[ ! -e $stats_path ]]; then
+ btrfs dev stats -c $mnt >$stats_path ||: # populate initial reading
+ elif ! btrfs dev stats -c $mnt >$tmp; then
+ if ! diff -q $stats_path $tmp; then
+ mv $stats_path $stats_path.1
+ cat $tmp >$stats_path
+ diff=$(diff -u $stats_path $tmp 2>&1 ||:)
+ printf "diff of: btrfs dev stats -c %s\n%s\n" "$mnt" "$diff"
+ exim -odf -i root <<EOF
+From: root@$(hostname -f)
+To: root@$(hostname -f)
+Subject: btrfsmaint: device stats changed for $mnt
+
+diff of: btrfs dev stats -c $mnt
+$diff
+EOF
+ fi
+ fi
+ rm -f $tmp
+ fi
+ #### end look for diff in stats, eg: increasing error count ####
+
+ if $check; then
+ if ! $locked; then
+ if $dryrun; then
+ echo "$0: not idle. if this wasnt a dry run, btrfs scrub cancel $mnt"
+ else
+ btrfs scrub cancel $mnt &>/dev/null ||:
+ fi
+ fi
+ continue
+ fi
+
+ # for comparing before and after balance.
+ # the log is already fairly verbose, so commented.
+ # e btrfs filesystem df $mnt
+ # e df -H $mnt
+ if btrfs filesystem df $mnt | grep -q "Data+Metadata"; then
+ for usage in $dusage; do
+ e ionice -c 3 btrfs balance start -dusage=$usage -musage=$usage $mnt
+ done
+ else
+ e ionice -c 3 btrfs balance start -dusage=0 $mnt
+ for usage in $dusage; do
+ e ionice -c 3 btrfs balance start -dusage=$usage $mnt
+ done
+ e ionice -c 3 btrfs balance start -musage=0 $mnt
+ for usage in $musage; do
+ e ionice -c 3 btrfs balance start -musage=$usage $mnt
+ done
+ fi
+ date=
+ scrub_status=$(btrfs scrub status $mnt)
+ if printf "%s\n" "$scrub_status" | grep -i '^status:[[:space:]]*finished$' &>/dev/null; then
+ date=$(printf "%s\n" "$scrub_status" | sed -rn 's/^Scrub started:[[:space:]]*(.*)/\1/p')
+ fi
+ if [[ ! $date ]]; then
+ # output from older versions, at least btrfs v4.15.1
+ date=$(
+ printf "%s\n" "$scrub_status" | \
+ sed -rn 's/^\s*scrub started at (.*) and finished.*/\1/p'
+ )
+ fi
+ if ! $force && [[ $date ]]; then
+ if $dryrun; then
+ echo "$0: last scrub finish for $mnt: $date"
+ fi
+ date=$(date --date="$date" +%s)
+ # if date is sooner than 60 days ago
+ # the wiki recommends 30 days or so, but
+ # I'm going with 60 days.
+ if (( date > EPOCHSECONDS - 60*60*24*60 )); then
+ if $dryrun; then
+ echo "$0: skiping scrub of $mnt, last was $(( (EPOCHSECONDS - date) / 60/60/24 )) days ago, < 30 days"
+ fi
+ continue
+ fi
+ fi
+ # btrfsmaintenance does -c 2 -n 4, but I want lowest pri.
+ e btrfs scrub start -Bd -c 3 $mnt
+
+ # We normally only do one disk since this is meant to be run in
+ # downtime and if we try to do all disks, we invariably end up doing
+ # a scrub after downtime. So, just do one disk per day.
+ if ! $force; then
+ return 0
+ fi
+ done
+}
+
+loop-main() {
+ while true; do
+ main
+ sleep 60
+ done
+}
+
+if $check; then
+ loop-main
+else
+ main
+fi