decrypt data-partition in twrp I messed up my phone trying to get open-gapps working on CM 13.
I can't even get into my OS only into recovery mode. I tried flashing several CM-Versions, but that doesn't change much.
I think the problem is, that my dalvik is corrupted. My data-partition is encrypted with a 3x3 pattern and TWRP can't decrypt it, so I can't wipe dalvik. I tried several variations of twrp decrypt, but they don't work. Now I am trying to flash cryptfs since I found a HowTo, which told me to use this commands:

setprop ro.crypto.state encrypted
vdc cryptfs checkpw 'pattern'
mount /dev/block/dm-0 /data


The problem is, that cryptfs is not installed. I tried to flash cryptfs, with a custom made zip-file, but it seems, the cryptfs-installation is also trying to write into /data and just aborts, since it can't mount it.

I really like to avoid making a factory-reset before getting my data out.
Any suggestions?
(I have a Sony Xperia M using nicky-cm)
My data-partition is encrypted with a 3x3 pattern and TWRP can't
  decrypt it


This can be solved by considering the 3x3 grid as the numbers on the keypad. For Example, consider a pattern that looks like the uppercase L character.

↓ o o  |  1 2 3
↓ o o  |  4 5 6
↓ → →  |  7 8 9


here, your password would be 14789