#!/bin/bash
# btrfs_scrub start <dev> <options> 
# btrfs_scrub status <dev>
# btrfs_scrub cancel <dev> 

case "$1" in
'start')
  # one might wonder: why exec the scrub command, passing -B and put in background, vs just
  # executing scrub without -B and without explicit background?  It's because it handles case
  # where user adds -B themselves as one of the options, which would hang webGui process until
  # scrub completes, which would not be good.  (btrfs balance does not have -B option btw)
  exec /sbin/btrfs scrub start -B $3 $2 &>/dev/null &
;;
'status')
  # first output whatever the status is to stdout
  /sbin/btrfs scrub status $2
  # establish retval of this script: 0 running, 1 not running
  /sbin/btrfs scrub status $2 | grep -q running
;;
'cancel')
  /sbin/btrfs scrub cancel $2 &>/dev/null
;;
esac