ladybird/Kernel/FileSystem/DevPtsFS.h
Andreas Kling c44b4d61f3 Kernel: Make Inode::lookup() return a RefPtr<Inode>
Previously this API would return an InodeIdentifier, which meant that
there was a race in path resolution where an inode could be unlinked
in between finding the InodeIdentifier for a path component, and
actually resolving that to an Inode object.

Attaching a test that would quickly trip an assertion before.

Test: Kernel/path-resolution-race.cpp
2020-02-01 10:56:17 +01:00

81 lines
3.3 KiB
C++

/*
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@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:
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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#pragma once
#include <AK/Types.h>
#include <Kernel/FileSystem/FileSystem.h>
#include <Kernel/FileSystem/Inode.h>
class SlavePTY;
class DevPtsFSInode;
class DevPtsFS final : public FS {
public:
virtual ~DevPtsFS() override;
static NonnullRefPtr<DevPtsFS> create();
virtual bool initialize() override;
virtual const char* class_name() const override { return "DevPtsFS"; }
virtual InodeIdentifier root_inode() const override;
virtual RefPtr<Inode> create_inode(InodeIdentifier parent_inode, const String& name, mode_t, off_t size, dev_t, uid_t, gid_t, int& error) override;
virtual RefPtr<Inode> create_directory(InodeIdentifier parent_inode, const String& name, mode_t, uid_t, gid_t, int& error) override;
virtual RefPtr<Inode> get_inode(InodeIdentifier) const override;
static void register_slave_pty(SlavePTY&);
static void unregister_slave_pty(SlavePTY&);
private:
DevPtsFS();
RefPtr<DevPtsFSInode> m_root_inode;
};
class DevPtsFSInode final : public Inode {
friend class DevPtsFS;
public:
virtual ~DevPtsFSInode() override;
private:
DevPtsFSInode(DevPtsFS&, unsigned index);
// ^Inode
virtual ssize_t read_bytes(off_t, ssize_t, u8* buffer, FileDescription*) const override;
virtual InodeMetadata metadata() const override;
virtual bool traverse_as_directory(Function<bool(const FS::DirectoryEntry&)>) const override;
virtual RefPtr<Inode> lookup(StringView name) override;
virtual void flush_metadata() override;
virtual ssize_t write_bytes(off_t, ssize_t, const u8* buffer, FileDescription*) override;
virtual KResult add_child(InodeIdentifier child_id, const StringView& name, mode_t) override;
virtual KResult remove_child(const StringView& name) override;
virtual size_t directory_entry_count() const override;
virtual KResult chmod(mode_t) override;
virtual KResult chown(uid_t, gid_t) override;
InodeMetadata m_metadata;
};