WHY DOES F2FS MAKE TWRP SO SLOW?
When TWRP boots up or wipes partitions and a few other scenarios, it checks each partition to see how much disk space is used. Ext4 handles disk usage calls quite efficiently and will finish this very fast. F2FS on the other hand is very slow when it comes to checking disk usage. We're unsure why this is. Every file on the F2FS formatted partition adds a little more time, and
a device that is 30 GB full could take up to 10 minutes to boot TWRP!
I suggest switching your data partition to ext4 -
all the f2fs hype is merely from benchmarks that don't actually represent real world use (ie. you're not writing thousands of files per second)
For someone who doesn't do lots of write access to their data partition, ext4 can actually be advantageous (it has faster access times and reads!)
WHY DOES MY SCREEN TURN BLACK AND TWRP DOESN'T BOOT?
There's some issues with the f2fs file system when going between the version used in Android Linux stable, and the new 4.10 backport f2fs used by Jaeguek Kim's f2fs-stable branch.
While both editions of f2fs are relatively stable, they are also incompatible with each other. It would appear that there was a slight structure change that occurred sometime during the development in 2015 that introduced a backwards compatibility issue.
Unfortunately, this means if you use a ROM that is using the 4.10 backport f2fs drivers, you will boot loop with this build of TWRP.
The official TWRP uses the Android Linux stable f2fs drivers.
But wait, there's more!
I'm now providing the official TWRP with backported f2fs drivers.
You can download it here:
https://build.nethunter.com/twrp/one...-oneplus3t.img
Warning: Do not flash this if you are using a ROM with the stable f2fs drivers from 2014!
Your ROM/kernel developer will state which TWRP build you should use with their ROM/kernel on their thread, if they do not, then do not use this build!
MY EXT4 DATA PARTITION WON'T DECRYPT
Unfortunately at this time TWRP only supports decrypting the filesystem that's listed in the recovery fstab.
That's why I made you an awesome flashable zip to swap it between f2fs and ext4!
Here you go:https://build.nethunter.com/android-...a-fstype-swap/
All you have to do is flash it on any TWRP version to change the default filesystem of /data between ext4 and f2fs.
You can copy it to your /cache partition if you are rooted and flash it from there. You can also flash it using adb:
adb push twrp-data-fstype-swap-*.zip /tmp/swap.zip
adb shell twrp install /tmp/swap.zip
After that, all you need to do is reboot recovery.
Note: This does not touch your data. It will not format anything. It only changes TWRP.