[xfstests PATCH v2] ext4/053: test changing test_dummy_encryption on remount

[Eric Biggers <ebiggers@kernel.org>]

From: Eric Biggers <ebiggers@google.com>

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>
---

v2: added info about fixing commit, and added a Reviewed-by tag

 tests/ext4/053 | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/ext4/053 b/tests/ext4/053
index 23e553c5..555e474e 100755
--- 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

base-commit: 0882b0913eae6fd6d2010323da1dde0ff96bf7d4
-- 
2.36.1