From 4f992242554dc205a18c9f11509a0f19dc9a2306 Mon Sep 17 00:00:00 2001
From: Norman Feske <norman.feske@genode-labs.com>
Date: Sun, 17 Mar 2019 13:37:02 +0100
Subject: [PATCH] ram_fs: increase max file size on 64 bit to 8 GiB

Fixes #2315
---
 repos/os/include/ram_fs/chunk.h        |  8 ++---
 repos/os/include/ram_fs/param.h        | 42 ++++++++++++++++++++++++++
 repos/os/recipes/src/vfs/content.mk    |  6 ++--
 repos/os/src/lib/vfs/ram_file_system.h | 12 +++++---
 repos/os/src/server/ram_fs/file.h      |  9 +++---
 5 files changed, 63 insertions(+), 14 deletions(-)
 create mode 100644 repos/os/include/ram_fs/param.h

diff --git a/repos/os/include/ram_fs/chunk.h b/repos/os/include/ram_fs/chunk.h
index 22b6a1f3ed..f0ebbd4f6f 100644
--- a/repos/os/include/ram_fs/chunk.h
+++ b/repos/os/include/ram_fs/chunk.h
@@ -28,8 +28,8 @@ namespace File_system {
 
 	class Chunk_base;
 
-	template <unsigned>           class Chunk;
-	template <unsigned, typename> class Chunk_index;
+	template <size_t>           class Chunk;
+	template <size_t, typename> class Chunk_index;
 }
 
 
@@ -97,7 +97,7 @@ class File_system::Chunk_base : Noncopyable
 /**
  * Chunk of bytes used as leaf in hierarchy of chunk indices
  */
-template <unsigned CHUNK_SIZE>
+template <Genode::size_t CHUNK_SIZE>
 class File_system::Chunk : public Chunk_base
 {
 	private:
@@ -177,7 +177,7 @@ class File_system::Chunk : public Chunk_base
 };
 
 
-template <unsigned NUM_ENTRIES, typename ENTRY_TYPE>
+template <Genode::size_t NUM_ENTRIES, typename ENTRY_TYPE>
 class File_system::Chunk_index : public Chunk_base
 {
 	public:
diff --git a/repos/os/include/ram_fs/param.h b/repos/os/include/ram_fs/param.h
new file mode 100644
index 0000000000..288fec135d
--- /dev/null
+++ b/repos/os/include/ram_fs/param.h
@@ -0,0 +1,42 @@
+/*
+ * \brief  Dimensioning of the hierarchic 'Chunk' structure for the RAM fs
+ * \author Norman Feske
+ * \date   2019-03-17
+ */
+
+/*
+ * Copyright (C) 2019 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+#ifndef _INCLUDE__RAM_FS__PARAM_H_
+#define _INCLUDE__RAM_FS__PARAM_H_
+
+/* Genode includes */
+#include <base/stdint.h>
+
+namespace Ram_fs
+{
+	using Genode::size_t;
+
+	/*
+	 * Let number of level-0 and level-1 entries depend on the machine-word
+	 * size to allow the use of more than 2 GiB on 64-bit machines.
+	 *
+	 * 32 bit: 64*64*128*4096   = 2 GiB
+	 * 64 bit: 128*128*128*4096 = 8 GiB
+	 */
+	static constexpr size_t num_level_0_entries()
+	{
+		return sizeof(size_t) == 8 ? 128 : 64;
+	}
+
+	static constexpr size_t num_level_1_entries() { return num_level_0_entries(); }
+	static constexpr size_t num_level_2_entries() { return 128; }
+	static constexpr size_t num_level_3_entries() { return 4096; }
+}
+
+#endif /* _INCLUDE__RAM_FS__PARAM_H_ */
+
diff --git a/repos/os/recipes/src/vfs/content.mk b/repos/os/recipes/src/vfs/content.mk
index ad62f2736d..9d6690aa74 100644
--- a/repos/os/recipes/src/vfs/content.mk
+++ b/repos/os/recipes/src/vfs/content.mk
@@ -1,8 +1,10 @@
 SRC_DIR = include/file_system src/server/vfs
 include $(GENODE_DIR)/repos/base/recipes/src/content.inc
 
+MIRROR_FROM_REP_DIR += $(addprefix include/ram_fs/,chunk.h param.h) \
+                       lib/mk/vfs.mk src/lib/vfs
 
-content: include/ram_fs/chunk.h lib/mk/vfs.mk src/lib/vfs
+content: $(MIRROR_FROM_REP_DIR)
 
-include/vfs include/ram_fs/chunk.h lib/mk/vfs.mk src/lib/vfs:
+$(MIRROR_FROM_REP_DIR):
 	$(mirror_from_rep_dir)
diff --git a/repos/os/src/lib/vfs/ram_file_system.h b/repos/os/src/lib/vfs/ram_file_system.h
index 69b7ce1d17..9096958e96 100644
--- a/repos/os/src/lib/vfs/ram_file_system.h
+++ b/repos/os/src/lib/vfs/ram_file_system.h
@@ -15,6 +15,7 @@
 #define _INCLUDE__VFS__RAM_FILE_SYSTEM_H_
 
 #include <ram_fs/chunk.h>
+#include <ram_fs/param.h>
 #include <vfs/file_system.h>
 #include <dataspace/client.h>
 #include <util/avl_tree.h>
@@ -25,6 +26,9 @@ namespace Vfs_ram {
 
 	using namespace Genode;
 	using namespace Vfs;
+	using namespace Ram_fs;
+	using File_system::Chunk;
+	using File_system::Chunk_index;
 
 	struct Io_handle;
 	struct Watch_handle;
@@ -235,10 +239,10 @@ class Vfs_ram::File : public Vfs_ram::Node
 {
 	private:
 
-		typedef ::File_system::Chunk<4096>      Chunk_level_3;
-		typedef ::File_system::Chunk_index<128, Chunk_level_3> Chunk_level_2;
-		typedef ::File_system::Chunk_index<64,  Chunk_level_2> Chunk_level_1;
-		typedef ::File_system::Chunk_index<64,  Chunk_level_1> Chunk_level_0;
+		typedef Chunk      <num_level_3_entries()>                Chunk_level_3;
+		typedef Chunk_index<num_level_2_entries(), Chunk_level_3> Chunk_level_2;
+		typedef Chunk_index<num_level_1_entries(), Chunk_level_2> Chunk_level_1;
+		typedef Chunk_index<num_level_0_entries(), Chunk_level_1> Chunk_level_0;
 
 		Chunk_level_0 _chunk;
 		file_size     _length = 0;
diff --git a/repos/os/src/server/ram_fs/file.h b/repos/os/src/server/ram_fs/file.h
index a1cfc9e820..e7df3cd4c9 100644
--- a/repos/os/src/server/ram_fs/file.h
+++ b/repos/os/src/server/ram_fs/file.h
@@ -20,6 +20,7 @@
 
 /* local includes */
 #include <ram_fs/chunk.h>
+#include <ram_fs/param.h>
 #include "node.h"
 
 namespace Ram_fs
@@ -36,10 +37,10 @@ class Ram_fs::File : public Node
 {
 	private:
 
-		typedef Chunk<4096>                     Chunk_level_3;
-		typedef Chunk_index<128, Chunk_level_3> Chunk_level_2;
-		typedef Chunk_index<64,  Chunk_level_2> Chunk_level_1;
-		typedef Chunk_index<64,  Chunk_level_1> Chunk_level_0;
+		typedef Chunk      <num_level_3_entries()>                Chunk_level_3;
+		typedef Chunk_index<num_level_2_entries(), Chunk_level_3> Chunk_level_2;
+		typedef Chunk_index<num_level_1_entries(), Chunk_level_2> Chunk_level_1;
+		typedef Chunk_index<num_level_0_entries(), Chunk_level_1> Chunk_level_0;
 
 		Chunk_level_0 _chunk;