235 lines
6.2 KiB
C++
235 lines
6.2 KiB
C++
/*
|
|
* \brief File-system factory implementation
|
|
* \author Norman Feske
|
|
* \date 2014-04-09
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2014-2018 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.
|
|
*/
|
|
|
|
|
|
/* Genode includes */
|
|
#include <vfs/file_system_factory.h>
|
|
#include <base/shared_object.h>
|
|
|
|
/* supported builtin file systems */
|
|
#include <block_file_system.h>
|
|
#include <fs_file_system.h>
|
|
#include <inline_file_system.h>
|
|
#include <log_file_system.h>
|
|
#include <null_file_system.h>
|
|
#include <ram_file_system.h>
|
|
#include <rom_file_system.h>
|
|
#include <rtc_file_system.h>
|
|
#include <symlink_file_system.h>
|
|
#include <tar_file_system.h>
|
|
#include <terminal_file_system.h>
|
|
#include <zero_file_system.h>
|
|
|
|
|
|
namespace Vfs {
|
|
|
|
using Vfs::Io_response_handler;
|
|
|
|
template <typename> struct Builtin_entry;
|
|
struct External_entry;
|
|
}
|
|
|
|
|
|
using Fs_type_name = Vfs::Global_file_system_factory::Fs_type_name;
|
|
using Node_name = Vfs::Global_file_system_factory::Node_name;
|
|
using Library_name = Vfs::Global_file_system_factory::Library_name;
|
|
|
|
|
|
struct Vfs::Global_file_system_factory::Entry_base : Vfs::File_system_factory,
|
|
private Genode::List<Entry_base>::Element
|
|
{
|
|
friend class Genode::List<Entry_base>;
|
|
|
|
using Genode::List<Entry_base>::Element::next;
|
|
|
|
Fs_type_name name;
|
|
|
|
Entry_base(Fs_type_name const &name) : name(name) { }
|
|
|
|
bool matches(Genode::Xml_node node) const {
|
|
return node.has_type(name.string()); }
|
|
};
|
|
|
|
|
|
template <typename FILE_SYSTEM>
|
|
struct Vfs::Builtin_entry : Vfs::Global_file_system_factory::Entry_base
|
|
{
|
|
Builtin_entry() : Entry_base(FILE_SYSTEM::name()) { }
|
|
|
|
Vfs::File_system *create(Vfs::Env &env, Genode::Xml_node node) override {
|
|
return new (env.alloc()) FILE_SYSTEM(env, node); }
|
|
};
|
|
|
|
|
|
struct Vfs::External_entry : Vfs::Global_file_system_factory::Entry_base
|
|
{
|
|
File_system_factory &_fs_factory;
|
|
|
|
External_entry(Fs_type_name const &name,
|
|
File_system_factory &fs_factory)
|
|
:
|
|
Entry_base(name), _fs_factory(fs_factory) { }
|
|
|
|
File_system *create(Vfs::Env &env,
|
|
Genode::Xml_node config) override
|
|
{
|
|
return _fs_factory.create(env, config);
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Add builtin File_system type
|
|
*/
|
|
template <typename FILE_SYSTEM>
|
|
void Vfs::Global_file_system_factory::_add_builtin_fs()
|
|
{
|
|
_list.insert(new (&_md_alloc) Builtin_entry<FILE_SYSTEM>());
|
|
}
|
|
|
|
|
|
/**
|
|
* Lookup and create File_system instance
|
|
*/
|
|
Vfs::File_system*
|
|
Vfs::Global_file_system_factory::_try_create(Vfs::Env &env,
|
|
Genode::Xml_node config)
|
|
{
|
|
for (Entry_base *e = _list.first(); e; e = e->next())
|
|
if (e->matches(config)) return e->create(env, config);
|
|
return nullptr;
|
|
}
|
|
|
|
|
|
/**
|
|
* Return matching library name for a given vfs node name
|
|
*/
|
|
Library_name Vfs::Global_file_system_factory::_library_name(Node_name const &node_name)
|
|
{
|
|
char lib_name [Library_name::capacity()];
|
|
Genode::snprintf(lib_name, sizeof(lib_name), "libvfs_%s.so",
|
|
node_name.string());
|
|
|
|
return Library_name(lib_name);
|
|
}
|
|
|
|
|
|
/**
|
|
* \throw Factory_not_available
|
|
*/
|
|
Vfs::File_system_factory &Vfs::Global_file_system_factory::_load_factory(Vfs::Env &env,
|
|
Library_name const &lib_name)
|
|
{
|
|
Genode::Shared_object *shared_object = nullptr;
|
|
|
|
try {
|
|
shared_object = new (env.alloc())
|
|
Genode::Shared_object(env.env(), env.alloc(), lib_name.string(),
|
|
Genode::Shared_object::BIND_LAZY,
|
|
Genode::Shared_object::DONT_KEEP);
|
|
|
|
typedef Vfs::File_system_factory *(*Query_fn)();
|
|
|
|
Query_fn query_fn = shared_object->lookup<Query_fn>(_factory_symbol());
|
|
|
|
return *query_fn();
|
|
|
|
} catch (Genode::Shared_object::Invalid_rom_module) {
|
|
Genode::warning("could not open '", lib_name, "'");
|
|
throw Factory_not_available();
|
|
|
|
} catch (Genode::Shared_object::Invalid_symbol) {
|
|
Genode::warning("could not find symbol '",
|
|
Genode::Cstring(_factory_symbol()),
|
|
"' in '", lib_name, "'");
|
|
|
|
Genode::destroy(env.alloc(), shared_object);
|
|
throw Factory_not_available();
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* Try to load external File_system_factory provider
|
|
*/
|
|
bool Vfs::Global_file_system_factory::_probe_external_factory(Vfs::Env &env,
|
|
Genode::Xml_node node)
|
|
{
|
|
Library_name const lib_name = _library_name(node.type());
|
|
|
|
try {
|
|
_list.insert(new (env.alloc())
|
|
External_entry(node.type().string(), _load_factory(env, lib_name)));
|
|
return true;
|
|
|
|
} catch (Factory_not_available) { return false; }
|
|
}
|
|
|
|
|
|
/**
|
|
* Create and return a new file-system
|
|
*/
|
|
Vfs::File_system *Vfs::Global_file_system_factory::create(Vfs::Env &env,
|
|
Genode::Xml_node node)
|
|
{
|
|
try {
|
|
/* try if type is handled by the currently registered fs types */
|
|
if (Vfs::File_system *fs = _try_create(env, node))
|
|
return fs;
|
|
/* if the builtin fails, do not try loading an external */
|
|
} catch (...) { return nullptr; }
|
|
|
|
try {
|
|
/* probe for file system implementation available as shared lib */
|
|
if (_probe_external_factory(env, node)) {
|
|
/* try again with the new file system type loaded */
|
|
if (Vfs::File_system *fs = _try_create(env, node))
|
|
return fs;
|
|
}
|
|
} catch (...) { }
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
|
|
/**
|
|
* Register an additional factory for new file-system type
|
|
*/
|
|
void Vfs::Global_file_system_factory::extend(char const *name, File_system_factory &factory)
|
|
{
|
|
_list.insert(new (&_md_alloc)
|
|
External_entry(name, factory));
|
|
}
|
|
|
|
|
|
/**
|
|
* Constructor
|
|
*/
|
|
Vfs::Global_file_system_factory::Global_file_system_factory(Genode::Allocator &alloc)
|
|
:
|
|
_md_alloc(alloc)
|
|
{
|
|
_add_builtin_fs<Vfs::Tar_file_system>();
|
|
_add_builtin_fs<Vfs::Fs_file_system>();
|
|
_add_builtin_fs<Vfs::Terminal_file_system::Compound_file_system>();
|
|
_add_builtin_fs<Vfs::Null_file_system>();
|
|
_add_builtin_fs<Vfs::Zero_file_system>();
|
|
_add_builtin_fs<Vfs::Block_file_system>();
|
|
_add_builtin_fs<Vfs::Log_file_system>();
|
|
_add_builtin_fs<Vfs::Rom_file_system>();
|
|
_add_builtin_fs<Vfs::Inline_file_system>();
|
|
_add_builtin_fs<Vfs::Rtc_file_system>();
|
|
_add_builtin_fs<Vfs::Ram_file_system>();
|
|
_add_builtin_fs<Vfs::Symlink_file_system>();
|
|
}
|