b0b92e4ee2
This patch enables the use of the VFS from VFS plugins by passing a reference of the root directory to the constructors of file-system instances. Since it changes the signature of 'Vfs::Dir_file_system', any code that uses the VFS directly requires an adaptation. Fixes #2701
130 lines
3.2 KiB
C++
130 lines
3.2 KiB
C++
/*
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* \brief LOG file system
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* \author Norman Feske
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* \date 2014-04-11
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*/
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/*
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* Copyright (C) 2014-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _INCLUDE__VFS__LOG_FILE_SYSTEM_H_
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#define _INCLUDE__VFS__LOG_FILE_SYSTEM_H_
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#include <log_session/connection.h>
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#include <vfs/single_file_system.h>
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#include <util/reconstructible.h>
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namespace Vfs { class Log_file_system; }
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class Vfs::Log_file_system : public Single_file_system
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{
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private:
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typedef Genode::String<64> Label;
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Label _label;
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Genode::Constructible<Genode::Log_connection> _log_connection { };
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Genode::Constructible<Genode::Log_session_client> _log_client { };
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Genode::Log_session & _log_session(Genode::Env &env)
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{
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if (_label.valid()) {
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_log_connection.construct(env, _label);
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return *_log_connection;
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} else {
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_log_client.construct(
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Genode::reinterpret_cap_cast<Genode::Log_session>
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(env.parent().session_cap(Genode::Parent::Env::log())));
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return *_log_client;
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}
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}
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Genode::Log_session &_log;
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class Log_vfs_handle : public Single_vfs_handle
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{
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private:
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Genode::Log_session &_log;
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public:
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Log_vfs_handle(Directory_service &ds,
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File_io_service &fs,
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Genode::Allocator &alloc,
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Genode::Log_session &log)
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: Single_vfs_handle(ds, fs, alloc, 0),
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_log(log) { }
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Read_result read(char *, file_size, file_size &out_count) override
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{
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out_count = 0;
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return READ_OK;
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}
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Write_result write(char const *src, file_size count,
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file_size &out_count) override
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{
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out_count = count;
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/* count does not include the trailing '\0' */
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while (count > 0) {
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char tmp[Genode::Log_session::MAX_STRING_LEN];
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int const curr_count = min(count, sizeof(tmp) - 1);
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memcpy(tmp, src, curr_count);
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tmp[curr_count > 0 ? curr_count : 0] = 0;
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_log.write(tmp);
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count -= curr_count;
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src += curr_count;
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}
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return WRITE_OK;
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}
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bool read_ready() { return false; }
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};
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public:
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Log_file_system(Genode::Env &env,
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Genode::Allocator&,
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Genode::Xml_node config,
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Io_response_handler &,
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File_system &)
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:
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Single_file_system(NODE_TYPE_CHAR_DEVICE, name(), config),
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_label(config.attribute_value("label", Label())),
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_log(_log_session(env))
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{ }
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static const char *name() { return "log"; }
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char const *type() override { return "log"; }
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/*********************************
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** Directory service interface **
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*********************************/
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Open_result open(char const *path, unsigned,
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Vfs_handle **out_handle,
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Allocator &alloc) override
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{
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if (!_single_file(path))
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return OPEN_ERR_UNACCESSIBLE;
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try {
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*out_handle = new (alloc)
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Log_vfs_handle(*this, *this, alloc, _log);
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return OPEN_OK;
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}
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catch (Genode::Out_of_ram) { return OPEN_ERR_OUT_OF_RAM; }
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catch (Genode::Out_of_caps) { return OPEN_ERR_OUT_OF_CAPS; }
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}
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};
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#endif /* _INCLUDE__VFS__LOG_FILE_SYSTEM_H_ */
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