ext4/053: test changing test_dummy_encryption on remount

The test_dummy_encryption mount option isn't supposed to be settable or
changeable via a remount, so add test cases for this.  This is a
regression test for a bug that was introduced in Linux v5.17 and fixed
in v5.19-rc3 by commit 85456054e10b ("ext4: fix up test_dummy_encryption
handling for new mount API").

Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>

diff --git a/tests/ext4/053 b/tests/ext4/053
index 23e553c5b21ec9b5e6f952d6741828594f8f29f4..555e474ef8a5a39f5af78a016fa5cb22c15329fe 100755 (executable)
--- a/tests/ext4/053
+++ b/tests/ext4/053
@@ -685,6 +685,9 @@ for fstype in ext2 ext3 ext4; do
                mnt test_dummy_encryption=v2
                not_mnt test_dummy_encryption=bad
                not_mnt test_dummy_encryption=
+               # Can't be set or changed on remount.
+               mnt_then_not_remount defaults test_dummy_encryption
+               mnt_then_not_remount test_dummy_encryption=v1 test_dummy_encryption=v2
                do_mkfs -O ^encrypt $SCRATCH_DEV ${SIZE}k
        fi
        not_mnt test_dummy_encryption