[PATCH v6 14/20] liveupdate: luo_file: add private argument to store runtime state

@@ -29,6 +29,10 @@ struct file;
  *                    this to the file being operated on.
  * @serialized_data:  The opaque u64 handle, preserve/prepare/freeze may update
  *                    this field.
+ * @private_data:     Private data for the file used to hold runtime state that
+ *                    is not preserved. Set by the handler's .preserve()
+ *                    callback, and must be freed in the handler's
+ *                    .unpreserve() callback.
  *
  * This structure bundles all parameters for the file operation callbacks.
  * The 'data' and 'file' fields are used for both input and output.

@@ -39,6 +43,7 @@ struct liveupdate_file_op_args {
 	bool retrieved;
 	struct file *file;
 	u64 serialized_data;
+	void *private_data;
 };
 
 /**

@@ -126,6 +126,10 @@ static LIST_HEAD(luo_file_handler_list);
  *                 This handle is passed back to the handler's .freeze(),
  *                 .retrieve(), and .finish() callbacks, allowing it to track
  *                 and update its serialized state across phases.
+ * @private_data:  Pointer to the private data for the file used to hold runtime
+ *                 state that is not preserved. Set by the handler's .preserve()
+ *                 callback, and must be freed in the handler's .unpreserve()
+ *                 callback.
  * @retrieved:     A flag indicating whether a user/kernel in the new kernel has
  *                 successfully called retrieve() on this file. This prevents
  *                 multiple retrieval attempts.

@@ -152,6 +156,7 @@ struct luo_file {
 	struct liveupdate_file_handler *fh;
 	struct file *file;
 	u64 serialized_data;
+	void *private_data;
 	bool retrieved;
 	struct mutex mutex;
 	struct list_head list;

@@ -309,6 +314,7 @@ int luo_preserve_file(struct luo_session *session, u64 token, int fd)
 		goto exit_err;
 	} else {
 		luo_file->serialized_data = args.serialized_data;
+		luo_file->private_data = args.private_data;
 		list_add_tail(&luo_file->list, &session->files_list);
 		session->count++;
 	}

@@ -356,6 +362,7 @@ void luo_file_unpreserve_files(struct luo_session *session)
 		args.session = (struct liveupdate_session *)session;
 		args.file = luo_file->file;
 		args.serialized_data = luo_file->serialized_data;
+		args.private_data = luo_file->private_data;
 		luo_file->fh->ops->unpreserve(&args);
 		luo_flb_file_unpreserve(luo_file->fh);
 

@@ -384,6 +391,7 @@ static int luo_file_freeze_one(struct luo_session *session,
 		args.session = (struct liveupdate_session *)session;
 		args.file = luo_file->file;
 		args.serialized_data = luo_file->serialized_data;
+		args.private_data = luo_file->private_data;
 
 		err = luo_file->fh->ops->freeze(&args);
 		if (!err)

@@ -405,6 +413,7 @@ static void luo_file_unfreeze_one(struct luo_session *session,
 		args.session = (struct liveupdate_session *)session;
 		args.file = luo_file->file;
 		args.serialized_data = luo_file->serialized_data;
+		args.private_data = luo_file->private_data;
 
 		luo_file->fh->ops->unfreeze(&args);
 	}