[PATCH v4 7/9] tune2fs: Prevent enabling encryption flag on encoding-aware fs

[Gabriel Krisman Bertazi <krisman@collabora.com>]

From: Gabriel Krisman Bertazi <krisman@collabora.co.uk>

The kernel will refuse to mount filesystems with the encryption and
encoding features enabled at the same time.  The encoding feature can
only be set at mount time, so we can just prevent encryption from being
set at a later time by tune2fs.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
---
 misc/tune2fs.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index a680b461cc86..4c92bee30b38 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -1459,6 +1459,12 @@ mmp_error:
 	}
 
 	if (FEATURE_ON(E2P_FEATURE_INCOMPAT, EXT4_FEATURE_INCOMPAT_ENCRYPT)) {
+		if (ext2fs_has_feature_fname_encoding(sb)) {
+			fputs(_("Cannot enable encrypt feature on filesystems "
+				"with the encoding feature enabled.\n"),
+			      stderr);
+			return 1;
+		}
 		fs->super->s_encrypt_algos[0] =
 			EXT4_ENCRYPTION_MODE_AES_256_XTS;
 		fs->super->s_encrypt_algos[1] =
-- 
2.20.0.rc1