ladybird/Kernel/FileSystem/FileSystem.h
2020-01-18 23:51:22 +01:00

134 lines
4.3 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "InodeIdentifier.h"
#include "InodeMetadata.h"
#include "UnixTypes.h"
#include <AK/String.h>
#include <AK/ByteBuffer.h>
#include <AK/Function.h>
#include <AK/HashMap.h>
#include <AK/OwnPtr.h>
#include <AK/RefCounted.h>
#include <AK/RefPtr.h>
#include <AK/WeakPtr.h>
#include <AK/kstdio.h>
#include <Kernel/Devices/DiskDevice.h>
#include <Kernel/KResult.h>
#include <Kernel/Lock.h>
static const u32 mepoch = 476763780;
class Inode;
class FileDescription;
class LocalSocket;
class VMObject;
class FS : public RefCounted<FS> {
friend class Inode;
public:
virtual ~FS();
unsigned fsid() const { return m_fsid; }
static FS* from_fsid(u32);
static void sync();
static void lock_all();
virtual bool initialize() = 0;
virtual const char* class_name() const = 0;
virtual InodeIdentifier root_inode() const = 0;
virtual bool supports_watchers() const { return false; }
bool is_readonly() const { return m_readonly; }
virtual unsigned total_block_count() const { return 0; }
virtual unsigned free_block_count() const { return 0; }
virtual unsigned total_inode_count() const { return 0; }
virtual unsigned free_inode_count() const { return 0; }
virtual KResult prepare_to_unmount() const { return KSuccess; }
// FIXME: This data structure is very clunky and unpleasant. Replace it with something nicer.
struct DirectoryEntry {
DirectoryEntry(const char* name, InodeIdentifier, u8 file_type);
DirectoryEntry(const char* name, size_t name_length, InodeIdentifier, u8 file_type);
char name[256];
size_t name_length { 0 };
InodeIdentifier inode;
u8 file_type { 0 };
};
virtual RefPtr<Inode> create_inode(InodeIdentifier parent_inode, const String& name, mode_t, off_t size, dev_t, uid_t, gid_t, int& error) = 0;
virtual RefPtr<Inode> create_directory(InodeIdentifier parent_inode, const String& name, mode_t, uid_t, gid_t, int& error) = 0;
virtual RefPtr<Inode> get_inode(InodeIdentifier) const = 0;
virtual void flush_writes() {}
int block_size() const { return m_block_size; }
virtual bool is_disk_backed() const { return false; }
protected:
FS();
void set_block_size(int);
mutable Lock m_lock { "FS" };
private:
unsigned m_fsid { 0 };
int m_block_size { 0 };
bool m_readonly { false };
};
inline FS* InodeIdentifier::fs()
{
return FS::from_fsid(m_fsid);
}
inline const FS* InodeIdentifier::fs() const
{
return FS::from_fsid(m_fsid);
}
inline bool InodeIdentifier::is_root_inode() const
{
return (*this) == fs()->root_inode();
}
namespace AK {
template<>
struct Traits<InodeIdentifier> : public GenericTraits<InodeIdentifier> {
static unsigned hash(const InodeIdentifier& inode) { return pair_int_hash(inode.fsid(), inode.index()); }
static void dump(const InodeIdentifier& inode) { kprintf("%02u:%08u", inode.fsid(), inode.index()); }
};
}