From 1c67e3bb43d264a44b86aff82a006158190ea688 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Josef=20S=C3=B6ntgen?= <josef.soentgen@genode-labs.com>
Date: Mon, 16 Dec 2013 16:46:00 +0100
Subject: [PATCH] os: extentend File_system interface with sync RPC

Users of a File_system_session might want to force a file system
to flush or rather to synchronize its internal cache. A concret
default implementation is provided because not all file systems
maintain an internal cache and are not required to synchronize
caches.

Fixes #1007.
---
 os/include/file_system_session/client.h             |  5 +++++
 .../file_system_session/file_system_session.h       | 13 ++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/os/include/file_system_session/client.h b/os/include/file_system_session/client.h
index c3279a6c61..3c52caab5f 100644
--- a/os/include/file_system_session/client.h
+++ b/os/include/file_system_session/client.h
@@ -104,6 +104,11 @@ namespace File_system {
 			{
 				call<Rpc_sigh>(node, sigh);
 			}
+
+			void sync()
+			{
+				call<Rpc_sync>();
+			}
 	};
 }
 
diff --git a/os/include/file_system_session/file_system_session.h b/os/include/file_system_session/file_system_session.h
index 6bf0452eb3..fd647ec872 100644
--- a/os/include/file_system_session/file_system_session.h
+++ b/os/include/file_system_session/file_system_session.h
@@ -280,6 +280,15 @@ namespace File_system {
 		 */
 		virtual void sigh(Node_handle, Signal_context_capability sigh) = 0;
 
+		/**
+		 * Synchronize file system
+		 *
+		 * This is only needed by file systems that maintain an internal
+		 * cache, which needs to be flushed on certain occasions. Therefore,
+		 * the default implementation just serves as a reminder.
+		 */
+		virtual void sync() { PWRN("sync() not implemented!"); }
+
 
 		/*******************
 		 ** RPC interface **
@@ -317,6 +326,7 @@ namespace File_system {
 		GENODE_RPC_THROW(Rpc_sigh, void, sigh,
 		                 GENODE_TYPE_LIST(Invalid_handle),
 		                 Node_handle, Signal_context_capability);
+		GENODE_RPC(Rpc_sync, void, sync);
 
 		/*
 		 * Manual type-list definition, needed because the RPC interface
@@ -335,8 +345,9 @@ namespace File_system {
 		        Meta::Type_tuple<Rpc_truncate,
 		        Meta::Type_tuple<Rpc_move,
 		        Meta::Type_tuple<Rpc_sigh,
+		        Meta::Type_tuple<Rpc_sync,
 		                         Meta::Empty>
-		        > > > > > > > > > > > Rpc_functions;
+		        > > > > > > > > > > > > Rpc_functions;
 	};
 }