Add __exit functions for llcrypt.
Initial fscrypt implementation lacks this because fscrypt is not a kernel module.

--- a/libcfs/include/libcfs/crypto/llcrypt.h
+++ b/libcfs/include/libcfs/crypto/llcrypt.h
@@ -108,6 +108,7 @@ static inline void llcrypt_handle_d_move
 
 /* crypto.c */
 extern int __init llcrypt_init(void);
+extern void __exit llcrypt_exit(void);
 extern void llcrypt_enqueue_decrypt_work(struct work_struct *);
 extern struct llcrypt_ctx *llcrypt_get_ctx(gfp_t);
 extern void llcrypt_release_ctx(struct llcrypt_ctx *);
--- a/libcfs/libcfs/crypto/crypto.c
+++ b/libcfs/libcfs/crypto/crypto.c
@@ -517,3 +517,22 @@ fail_free_queue:
 fail:
 	return err;
 }
+
+/**
+ * llcrypt_exit() - Clean up for fs encryption.
+ */
+void __exit llcrypt_exit(void)
+{
+	llcrypt_exit_keyring();
+
+	llcrypt_destroy();
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+
+	kmem_cache_destroy(llcrypt_info_cachep);
+	kmem_cache_destroy(llcrypt_ctx_cachep);
+	destroy_workqueue(llcrypt_read_workqueue);
+}
--- a/libcfs/libcfs/crypto/keyring.c
+++ b/libcfs/libcfs/crypto/keyring.c
@@ -231,6 +231,7 @@ void llcrypt_sb_free(struct super_block
 		lsi->lsi_master_keys = NULL;
 	}
 }
+EXPORT_SYMBOL(llcrypt_sb_free);
 
 /*
  * Find the specified master key in ->lsi_master_keys.
@@ -1003,3 +1004,9 @@ err_unregister_llcrypt:
 	unregister_key_type(&key_type_llcrypt);
 	return err;
 }
+
+void __exit llcrypt_exit_keyring(void)
+{
+	unregister_key_type(&key_type_llcrypt_user);
+	unregister_key_type(&key_type_llcrypt);
+}
--- a/libcfs/libcfs/crypto/llcrypt_private.h
+++ b/libcfs/libcfs/crypto/llcrypt_private.h
@@ -444,6 +444,8 @@ extern int llcrypt_verify_key_added(stru
 
 extern int __init llcrypt_init_keyring(void);
 
+extern void __exit llcrypt_exit_keyring(void);
+
 /* keysetup.c */
 
 struct llcrypt_mode {