Look at the top-answer of this post. Works perfectly on Xperia X too
lvm lvm> lvscan ACTIVE '/dev/sailfish/root' [2.44 GiB] inherit ACTIVE '/dev/sailfish/home' [18.25 GiB] inherit lvm> exit resize2fs /dev/sailfish/home 11G lvm lvm> lvresize -L -4096M /dev/sailfish/home lvm> lvresize -l +100%FREE /dev/sailfish/root lvm> lvscan ACTIVE '/dev/sailfish/root' [6.44 GiB] inherit ACTIVE '/dev/sailfish/home' [14.25 GiB] inherit lvm> exit resize2fs /dev/sailfish/home resize2fs /dev/sailfish/root exit