"This filesystem does not support encryption"?

[romanrm]

Hello,

Firstly, it is unclear whether the directory passed to "ext4-crypt create" needs to already exist. The expectation from a function named "create" is that it does not have to (and will be created by the tool), but apparently not so?

Secondly, it does not work at all even if I create the directory manually.

# ext4-crypt create test
Cannot get filesystem information for test: No such file or directory
Error: test does not belong to an ext4 filesystem.

# mkdir test

# ext4-crypt create test
This filesystem does not support encryption.
Please ensure your kernel has support for CONFIG_EXT4_ENCRYPTION.

# uname -a
Linux hostname 4.9.39-rm1+ #16 SMP Fri Jul 21 15:24:03 +05 2017 x86_64 GNU/Linux

# grep CONFIG_EXT4 /boot/config-4.9.39-rm1+ 
CONFIG_EXT4_FS=m
CONFIG_EXT4_USE_FOR_EXT2=y
CONFIG_EXT4_FS_POSIX_ACL=y
CONFIG_EXT4_FS_SECURITY=y
CONFIG_EXT4_ENCRYPTION=y
CONFIG_EXT4_FS_ENCRYPTION=y
# CONFIG_EXT4_DEBUG is not set

[romanrm]

I just found that you also need to do

tune2fs -O encrypt <blockdevice>

else it will not work. This needs to be mentioned in the instructions.