ext4/004 hangs with -o inlinecrypt,test_dummy_encryption

Hi all,

I've just been wanting to test my changes to the inline encruption fallback code, and it seems like ext/004 (the only ext4 dump test) hangs when using the following options:

export MKFS_OPTIONS='-O encrypt'
export MOUNT_OPTIONS="-o inlinecrypt,test_dummy_encryption"

I thought I did not see this before, but it reproduces back to at least Linux 6.17. This is in an uptodate Debian trixie VM. The dump/restore process look like in weird states:

   4727 ttyS0    T      0:00 /usr/sbin/dump -0 -f - /mnt/scratch/dump_restore_dir
   4728 ttyS0    T      0:00 /usr/sbin/restore -urvf -
   4729 ttyS0    T      0:00 /usr/sbin/dump -0 -f - /mnt/scratch/dump_restore_dir
   4730 ttyS0    T      0:00 /usr/sbin/dump -0 -f - /mnt/scratch/dump_restore_dir
   4731 ttyS0    T      0:00 /usr/sbin/dump -0 -f - /mnt/scratch/dump_restore_dir
   4732 ttyS0    T      0:00 /usr/sbin/dump -0 -f - /mnt/scratch/dump_restore_dir

I can reproduce this issue locally with both v6.18 and v6.0. The problem disappears after removing test_dummy_encryption, and it still reproduces when test_dummy_encryption is set alone in MOUNT_OPTIONS. Therefore, I believe the issue lies in test_dummy_encryption — it is an implementation of fscrypt.

Thanks,

Julian Sun <[email protected]>

cc linux-fscrypt

Julian Sun <[email protected]>

It seems to be a known failure. ext4/004, along with various other tests, is excluded by
https://github.com/tytso/xfstests-bld/blob/master/test-appliance/files/root/fs/ext4/cfg/encrypt.exclude
as follows:

ext4/004 // dump/restore doesn't handle quotas

I'm not sure why the comment mentions quotas. It probably should say "encryption", not "quotas".

Either way, the exclusion logic in xfstests-bld really should be incorporated directly into xfstests, e.g. by using _exclude_test_mount_option "test_dummy_encryption".

This seems to be a wider issue. Effectively, ext4's exclusion lists for xfstests are being maintained outside of xfstests itself.

- Eric