While it is quite straight forward ¹⁾ to resize any stack of LUKS, ext2,3,4, LVM, MSDOS or GPT partitions, it becomes strange if you're using Ubuntus package cryptsetup ²⁾

~ # lvresize -L 22.5G /dev/vg_sys/lv_home
~ # cryptsetup resize home
~ # resize2fs /dev/mapper/home
resize2fs 1.42.10 (18-May-2014)
resize2fs: Device or resource busy while trying to open /dev/mapper/home
Couldn't find valid filesystem superblock.
~ # mount | fgrep home  
/dev/mapper/home_unformatted on /home type ext3 (rw,relatime,data=ordered)
~ # resize2fs /dev/mapper/home_unformatted
resize2fs 1.42.10 (18-May-2014)
open: No such file or directory while opening /dev/mapper/home_unformatted
~ #

The remedy is simple:

dmsetup rename home home_unformatted
resize2fs /dev/mapper/home_unformatted
dmsetup rename home_unformatted home 

Linux LVM LUKS cryptsetup resize2fs