#!/bin/bash
# btrfs_check start <dev> <id> <options>
# btrfs_check status <dev> <id>
# btrfs_check cancel <dev> <id>
# btrfs_check reset <mountpoint>

# By default btrfs-check outputs to /var/lib/btrfs
mkdir -p /var/lib/btrfs

case "$1" in
'start')
	# Start the btrfs check process in the background and log output
	/sbin/btrfs check $4 $2 &> /var/lib/btrfs/check.status.$3 &
	pid=$!
	echo $pid > /var/lib/btrfs/check.pid.$3
	exit 0
;;
'status')
	# Check if the process is running and set the return value accordingly
	if [ -f /var/lib/btrfs/check.pid.$3 ]; then
		cat /var/lib/btrfs/check.status.$3
		pid=$(cat /var/lib/btrfs/check.pid.$3)
		if kill -0 $pid 2>/dev/null; then
			# Process is running
			exit 9
		else
			if [ -f /var/lib/btrfs/check.status.$3 ]; then
				rm -f /var/lib/btrfs/check.pid.$3
			fi
		fi
	else
		if [ -f /var/lib/btrfs/check.status.$3 ]; then
			cat /var/lib/btrfs/check.status.$3
		else
			echo "Not available"
		fi
	fi

	exit 0
;;
'cancel')
	# Cancel the btrfs check process
	if [ -f /var/lib/btrfs/check.pid.$3 ]; then
		pid=$(cat /var/lib/btrfs/check.pid.$3)
		kill $pid
		while kill -0 $pid 2>/dev/null; do
			sleep 1
		done
		echo -e "\nCancelled" >> /var/lib/btrfs/check.status.$3
		rm -f /var/lib/btrfs/check.pid.$3
	else
		echo "No process to cancel"
	fi

	exit 0
;;
'reset')
	exec /sbin/btrfs device stats -z $2
;;
*)
	echo "Invalid command"
	exit 0
;;
esac