As many users are facing issue because of data mount issue with TWRP on oreo, till it get fixed here is temporary solution.
Download file according root method you are using
1. For Magisk
2. For SuperSU
- Flash downloaded file from recovery - Ignore if any message with red color regarding data mount while flashing
- Reboot to system (This step is Must)
- Done !
Now again you can reboot to recovery to check for data mount fix.
PS : You need to reflash this again after every time you flash Kernel/Root/ROM
This can be use with any working TWRP for N8/any kernel stock/custom
Credits : Credits : @Chainfire @topjohnwu @osm0sis and some International forum discussion for original idea