Failed to use ecryptfs in Android device.

Hi,
I'm trying to mount ecryptfs on Android device(running in an goldfish emulator).
I menuconfiged kernel options, and I am sure I've got ecryptfs module compiled into the kernel.
so I mount it with following command in "adb shell":
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cd sdcard/
mkdir test/
mount -t ecryptfs test/ test/
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It then prints: mount: Invalid argument

So I check the ecryptfs source code, printing some log. And I find function "ecryptfs_parse_options" get a null in parameter "options" (goldfish/fs/ecryptfs/main.c: line 478). And the null parameter is passed through from mount system call.

QUESTION1: What is the "options" need to be parsed by ecryptfs_parse_options?

When I try to manually evaluate the "options" with some value such as 0 before invoke ecryptfs_parse_options() , it then prints in log:
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ecryptfs_parse_options: eCryptfs: unrecognized option [0]
ecryptfs_parse_options: You must supply at least one valid auth tok signature as a mount parameter; see the eCryptfs README
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QUESTION2:what are those "valid auth tok signature"?

However, when I check the README in ecryptfs userspace code packet, I don't get the answer I need. Futhermore, it makes me wondering:

QUESTION3:Must I use ecryptfs userspace code in order to make ecryptfs kernel code work in Android?

This is the first time I get involved in OpenSourceProject. I hope I'm questioning in the right way with understandable English ...
Thank you!