ladybird/Kernel/FileSystem/Inode.h

159 lines
6.0 KiB
C++

/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021, sin-ack <sin-ack@protonmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Error.h>
#include <AK/Function.h>
#include <AK/HashTable.h>
#include <AK/IntrusiveList.h>
#include <Kernel/FileSystem/FIFO.h>
#include <Kernel/FileSystem/FileSystem.h>
#include <Kernel/FileSystem/InodeIdentifier.h>
#include <Kernel/FileSystem/InodeMetadata.h>
#include <Kernel/Forward.h>
#include <Kernel/Library/ListedRefCounted.h>
#include <Kernel/Library/LockWeakPtr.h>
#include <Kernel/Locking/Mutex.h>
#include <Kernel/Memory/SharedInodeVMObject.h>
namespace Kernel {
enum class ShouldBlock {
No = 0,
Yes = 1
};
class Inode : public ListedRefCounted<Inode, LockType::Spinlock>
, public LockWeakable<Inode> {
friend class VirtualFileSystem;
friend class FileSystem;
friend class InodeFile;
public:
virtual ~Inode();
virtual void remove_from_secondary_lists() { }
FileSystem& fs() { return m_file_system; }
FileSystem const& fs() const { return m_file_system; }
FileSystemID fsid() const { return m_file_system.fsid(); }
InodeIndex index() const { return m_index; }
size_t size() const { return metadata().size; }
bool is_symlink() const { return metadata().is_symlink(); }
bool is_directory() const { return metadata().is_directory(); }
bool is_character_device() const { return metadata().is_character_device(); }
mode_t mode() const { return metadata().mode; }
InodeIdentifier identifier() const { return { fsid(), index() }; }
virtual InodeMetadata metadata() const = 0;
ErrorOr<size_t> write_bytes(off_t, size_t, UserOrKernelBuffer const& data, OpenFileDescription*);
ErrorOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const;
ErrorOr<size_t> read_until_filled_or_end(off_t, size_t, UserOrKernelBuffer buffer, OpenFileDescription*) const;
ErrorOr<void> truncate(u64);
virtual ErrorOr<void> attach(OpenFileDescription&) { return {}; }
virtual void detach(OpenFileDescription&) { }
virtual void did_seek(OpenFileDescription&, off_t) { }
virtual ErrorOr<void> traverse_as_directory(Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>) const = 0;
virtual ErrorOr<NonnullRefPtr<Inode>> lookup(StringView name) = 0;
virtual ErrorOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, UserID, GroupID) = 0;
virtual ErrorOr<void> add_child(Inode&, StringView name, mode_t) = 0;
virtual ErrorOr<void> remove_child(StringView name) = 0;
/// Replace child atomically, incrementing the link count of the replacement
/// inode and decrementing the older inode's.
virtual ErrorOr<void> replace_child(StringView name, Inode&) = 0;
virtual ErrorOr<void> chmod(mode_t) = 0;
virtual ErrorOr<void> chown(UserID, GroupID) = 0;
ErrorOr<NonnullRefPtr<Custody>> resolve_as_link(Credentials const&, Custody& base, RefPtr<Custody>* out_parent, int options, int symlink_recursion_level) const;
virtual ErrorOr<int> get_block_address(int) { return ENOTSUP; }
LockRefPtr<LocalSocket> bound_socket() const;
bool bind_socket(LocalSocket&);
bool unbind_socket();
bool is_metadata_dirty() const { return m_metadata_dirty; }
virtual ErrorOr<void> update_timestamps(Optional<UnixDateTime> atime, Optional<UnixDateTime> ctime, Optional<UnixDateTime> mtime);
virtual ErrorOr<void> increment_link_count();
virtual ErrorOr<void> decrement_link_count();
virtual ErrorOr<void> flush_metadata() = 0;
void will_be_destroyed();
ErrorOr<void> set_shared_vmobject(Memory::SharedInodeVMObject&);
LockRefPtr<Memory::SharedInodeVMObject> shared_vmobject() const;
static void sync_all();
void sync();
bool has_watchers() const;
ErrorOr<void> register_watcher(Badge<InodeWatcher>, InodeWatcher&);
void unregister_watcher(Badge<InodeWatcher>, InodeWatcher&);
ErrorOr<NonnullRefPtr<FIFO>> fifo();
bool can_apply_flock(flock const&, Optional<OpenFileDescription const&> = {}) const;
ErrorOr<void> apply_flock(Process const&, OpenFileDescription const&, Userspace<flock const*>, ShouldBlock);
ErrorOr<void> get_flock(OpenFileDescription const&, Userspace<flock*>) const;
void remove_flocks_for_description(OpenFileDescription const&);
Thread::FlockBlockerSet& flock_blocker_set() { return m_flock_blocker_set; }
protected:
Inode(FileSystem&, InodeIndex);
void set_metadata_dirty(bool);
ErrorOr<void> prepare_to_write_data();
void did_add_child(InodeIdentifier child_id, StringView);
void did_remove_child(InodeIdentifier child_id, StringView);
void did_modify_contents();
void did_delete_self();
mutable Mutex m_inode_lock { "Inode"sv };
ErrorOr<size_t> prepare_and_write_bytes_locked(off_t, size_t, UserOrKernelBuffer const& data, OpenFileDescription*);
virtual ErrorOr<size_t> write_bytes_locked(off_t, size_t, UserOrKernelBuffer const& data, OpenFileDescription*) = 0;
virtual ErrorOr<size_t> read_bytes_locked(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const = 0;
virtual ErrorOr<void> truncate_locked(u64) { return {}; }
private:
ErrorOr<bool> try_apply_flock(Process const&, OpenFileDescription const&, flock const&);
FileSystem& m_file_system;
InodeIndex m_index { 0 };
LockWeakPtr<Memory::SharedInodeVMObject> m_shared_vmobject;
LockWeakPtr<LocalSocket> m_bound_socket;
SpinlockProtected<HashTable<InodeWatcher*>, LockRank::None> m_watchers {};
bool m_metadata_dirty { false };
RefPtr<FIFO> m_fifo;
IntrusiveListNode<Inode> m_inode_list_node;
struct Flock {
off_t start;
off_t len;
OpenFileDescription const* owner;
pid_t pid;
short type;
};
Thread::FlockBlockerSet m_flock_blocker_set;
SpinlockProtected<Vector<Flock>, LockRank::None> m_flocks {};
public:
using AllInstancesList = IntrusiveList<&Inode::m_inode_list_node>;
static SpinlockProtected<Inode::AllInstancesList, LockRank::None>& all_instances();
};
}