On Mon, Aug 07, 2017 at 09:49:42AM -0400, Theodore Ts'o wrote:

On Mon, Aug 07, 2017 at 05:51:26PM +0800, Dai Xiang wrote:

quoted

On Mon, Aug 07, 2017 at 11:25:02AM +0800, Dai Xiang wrote:

quoted

Hi!

I use xfstests with ext4 fs to test, and i found a skip:

ext4/024         [not run] kernel does not support ext4 encryption

Yeah, the message printed is misleading, and should be fixed.
Checking to see whether the kernel supports encryption can be done by
checking for the existence of the file:

/sys/fs/ext4/features/encryption

quoted

i print the cmd:
/usr/sbin/xfs_io -i -c set_encpolicy /fs/scratch/tmpdir
/fs/scratch/tmpdir: failed to set encryption policy: Inappropriate
ioctl for device <===

Seems do not related to kconfig?

Yes, the issue is that you need to create the file system (or set via
tune2fs) the feature flag "encrypt".  To best test the read/write
paths, you should set the mount option test_dummy_encryption.  The
kvm-xfstests and gce-xfstests framework do all of this automatically.
From xfstests-bld/kvm-xfstests/test-appliance/files/root/cfg/fs/ext4/encrypt:

SIZE=small
export EXT_MKFS_OPTIONS="-O encrypt"
export EXT_MOUNT_OPTIONS="test_dummy_encryption"
REQUIRE_FEATURE=encryption
TESTNAME="Ext4 encryption"

There are a number tests that are known to fail; primarily having to
do with quota support, which doesn't play well with
test_dummy_encryption (that's more of a test problem than anything
else).  See the encrypt.exclude file in that directory for more
details.

Actually, this is one of the tests in the "encrypt" group, which format the
scratch device with "-O encrypt".  So I believe the printed message is correct.
Are you 100% sure that CONFIG_EXT4_ENCRYPTION is enabled in your kernel config
and that you are running the correct kernel?

Eric