gistfile1.sh

#/bin/bash

while true
do
	homeuuid=$(grep '/home' /etc/fstab  | awk '{print $1}' | cut -d = -f 2)
	ssd=$(lsblk -o KNAME,MODEL | grep SSD | cut -d ' ' -f 1)
	mounted=$(mount | grep /home | cut -d ' ' -f 1 )
	ssduuid=$(ls -la /dev/disk/by-uuid | grep bcache0 | awk '{print $9}')
	formatted=$( ls  /dev/bcache0 )

	homedev=$(ls -la /dev/disk/by-uuid/${homeuuid} | cut -d / -f 7 )


	if [ -z "$ssd" ]
	then
		echo "Cannot find SSD."
		exit
	fi

	if [ -r /dev/${ssd}1 ] 
	then
		echo "SSD has partitions. Wipe and reboot"
		# should I wipe it myself?
		# dd if=/dev/zero of=/dev/${ssd} count=32
		exit
	fi

	if [ ! -z "${mounted}" ]
	then

		if [ "$mounted" == "/dev/bcache0" ]
		then
			echo "Mounted and Enabled"
			exit
		else
			echo "Mounted and not Enabled"
			umount /home
		fi

	else

		if [ ! -z "$ssduuid"  ]
		then
			if [ "$ssduuid" == "$homeuuid" ]
			then
				echo "unmounted, bcache formatted and fstab edited"
				mount /home
			else
				echo	"unmounted, bcache formatted and fstab not edited"
				cp /etc/fstab /etc/fstab~
				sed s/${homeuuid}/${ssduuid}/ /etc/fstab~  > /etc/fstab
			fi
		else

			if [ -z "$formatted" ]
			then
				echo "unmounted not formatted"
				make-bcache -C /dev/${ssd}
				make-bcache -B /dev/${homedev}
		
			# appears to take a while before appearing.
				while [ ! -r /dev/bcache0 ]
				do
					echo "Waiting for bcache device..."
					sleep 1
				done
			else 
				echo "/dev/bcache0 exists but is not /home partition"
				mke2fs -t ext4 /dev/bcache0
			fi
				
		fi
	fi


sleep 1
done