[PATCH 03/35] fscrypt: disable all but standard v2 policies for extent encryption

[Josef Bacik]

The different encryption related options for fscrypt are too numerous to
support for extent based encryption.  Support for a few of these options
could possibly be added, but since they're niche options simply reject
them for file systems using extent based encryption.

Signed-off-by: Josef Bacik <jo...@toxicpanda.com>
---
 fs/crypto/policy.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index 8b8da04068b8..38807d0ee742 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -198,6 +198,12 @@ static bool fscrypt_supported_v1_policy(const struct 
fscrypt_policy_v1 *policy,
                return false;
        }
 
+       if (inode->i_sb->s_cop->flags & FS_CFLG_EXTENT_ENCRYPTION) {
+               fscrypt_warn(inode,
+                            "v1 policies can't be used on file systems that 
use extent encryption");
+               return false;
+       }
+
        return true;
 }
 
@@ -233,6 +239,12 @@ static bool fscrypt_supported_v2_policy(const struct 
fscrypt_policy_v2 *policy,
                return false;
        }
 
+       if ((inode->i_sb->s_cop->flags & FS_CFLG_EXTENT_ENCRYPTION) && count) {
+               fscrypt_warn(inode,
+                            "Encryption flags aren't supported on file systems 
that use extent encryption");
+               return false;
+       }
+
        if ((policy->flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) &&
            !supported_direct_key_modes(inode, policy->contents_encryption_mode,
                                        policy->filenames_encryption_mode))
-- 
2.41.0