Losing root after reboot
I'm facing some small problem with my Xperia.
I own this device for 4 days, so please consider me noob (only for this device).
So I've unlocked my bootloader, rooted the phone and installed CWM, but the problem is that it is losing root after every reboot (I have to flash SuperSu libraries each time to fix it).
I've seen a thread about this, how to re-root my phone, however I can't find it anymore.
Could You help me to root my phone permanently?