summary refs log tree commit diff
path: root/fs/crypto
diff options
context:
space:
mode:
Diffstat (limited to 'fs/crypto')
-rw-r--r--fs/crypto/hooks.c28
-rw-r--r--fs/crypto/policy.c7
2 files changed, 35 insertions, 0 deletions
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index 4081aae4bc35..fd4e5ae21077 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -122,6 +122,34 @@ int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry,
 }
 EXPORT_SYMBOL_GPL(__fscrypt_prepare_lookup);
 
+/**
+ * fscrypt_prepare_setflags() - prepare to change flags with FS_IOC_SETFLAGS
+ * @inode: the inode on which flags are being changed
+ * @oldflags: the old flags
+ * @flags: the new flags
+ *
+ * The caller should be holding i_rwsem for write.
+ *
+ * Return: 0 on success; -errno if the flags change isn't allowed or if
+ *	   another error occurs.
+ */
+int fscrypt_prepare_setflags(struct inode *inode,
+			     unsigned int oldflags, unsigned int flags)
+{
+	struct fscrypt_info *ci;
+	int err;
+
+	if (IS_ENCRYPTED(inode) && (flags & ~oldflags & FS_CASEFOLD_FL)) {
+		err = fscrypt_require_key(inode);
+		if (err)
+			return err;
+		ci = inode->i_crypt_info;
+		if (ci->ci_policy.version != FSCRYPT_POLICY_V2)
+			return -EINVAL;
+	}
+	return 0;
+}
+
 int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len,
 			      unsigned int max_len,
 			      struct fscrypt_str *disk_link)
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index f1cff83c151a..cf2a9d26ef7d 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -124,6 +124,13 @@ static bool fscrypt_supported_v1_policy(const struct fscrypt_policy_v1 *policy,
 					policy->filenames_encryption_mode))
 		return false;
 
+	if (IS_CASEFOLDED(inode)) {
+		/* With v1, there's no way to derive dirhash keys. */
+		fscrypt_warn(inode,
+			     "v1 policies can't be used on casefolded directories");
+		return false;
+	}
+
 	return true;
 }