[RFC PATCH 1/8] xfs_io/encrypt: remove unimplemented encryption modes

[Eric Biggers <ebiggers@kernel.org>]

From: Eric Biggers <ebiggers@google.com>

Although mode numbers were originally reserved for AES-256-GCM and
AES-256-CBC, these were never implemented in the kernel, and there are
no plans to do so anymore.  These mode numbers may be used for something
else in the future.  Also, xfstests (the only known user of the xfs_io
encryption commands) doesn't try to use them.  Finally, most of the
fscrypt constants have been given new names in the UAPI header, but the
unused constants have not been given new names since userspace should
just stop referencing them instead.

So remove them from xfs_io.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 io/encrypt.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/io/encrypt.c b/io/encrypt.c
index 8db35259..e8766dc1 100644
--- a/io/encrypt.c
+++ b/io/encrypt.c
@@ -49,8 +49,6 @@ struct fscrypt_policy {
 
 #define FS_ENCRYPTION_MODE_INVALID	0
 #define FS_ENCRYPTION_MODE_AES_256_XTS	1
-#define FS_ENCRYPTION_MODE_AES_256_GCM	2
-#define FS_ENCRYPTION_MODE_AES_256_CBC	3
 #define FS_ENCRYPTION_MODE_AES_256_CTS	4
 #endif /* FS_ENCRYPTION_MODE_AES_256_XTS */
 
@@ -74,7 +72,7 @@ set_encpolicy_help(void)
 " -v VERSION -- version of policy structure\n"
 "\n"
 " MODE can be numeric or one of the following predefined values:\n"
-"    AES-256-XTS, AES-256-CTS, AES-256-GCM, AES-256-CBC\n"
+"    AES-256-XTS, AES-256-CTS\n"
 " FLAGS and VERSION must be numeric.\n"
 "\n"
 " Note that it's only possible to set an encryption policy on an empty\n"
@@ -88,8 +86,6 @@ static const struct {
 } available_modes[] = {
 	{FS_ENCRYPTION_MODE_AES_256_XTS, "AES-256-XTS"},
 	{FS_ENCRYPTION_MODE_AES_256_CTS, "AES-256-CTS"},
-	{FS_ENCRYPTION_MODE_AES_256_GCM, "AES-256-GCM"},
-	{FS_ENCRYPTION_MODE_AES_256_CBC, "AES-256-CBC"},
 };
 
 static bool
-- 
2.23.0.rc1.153.gdeed80330f-goog