[3/4] fscrypt: disable all but standard v2 policies for extent encryption

Commit Message

Josef Bacik Sept. 15, 2023, 12:47 a.m. UTC

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 <[e-mail]>
---
 fs/crypto/policy.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Patch

diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index cb944338271d..3c8665c21ee8 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))