mirror of
https://github.com/SerenityOS/serenity
synced 2024-07-24 03:25:02 +00:00
ab8b043684
This adds try_* methods to AK::DoublyLinkedList and updates the Device class to use those to gracefully handle allocation failures. Refs #6369.
104 lines
3.5 KiB
C++
104 lines
3.5 KiB
C++
/*
|
|
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
// Device is the base class of everything that lives in the /dev directory.
|
|
//
|
|
// To expose a Device to the filesystem, simply pass two unique numbers to the constructor,
|
|
// and then mknod a file in /dev with those numbers.
|
|
//
|
|
// There are two main subclasses:
|
|
// - BlockDevice (random access)
|
|
// - CharacterDevice (sequential)
|
|
#include <AK/DoublyLinkedList.h>
|
|
#include <AK/Error.h>
|
|
#include <AK/Function.h>
|
|
#include <AK/HashMap.h>
|
|
#include <Kernel/Devices/AsyncDeviceRequest.h>
|
|
#include <Kernel/FileSystem/DeviceFileTypes.h>
|
|
#include <Kernel/FileSystem/File.h>
|
|
#include <Kernel/FileSystem/SysFS/Registry.h>
|
|
#include <Kernel/FileSystem/SysFS/Subsystems/DeviceIdentifiers/DeviceComponent.h>
|
|
#include <Kernel/FileSystem/SysFS/Subsystems/DeviceIdentifiers/SymbolicLinkDeviceComponent.h>
|
|
#include <Kernel/Library/LockRefPtr.h>
|
|
#include <Kernel/UnixTypes.h>
|
|
|
|
namespace Kernel {
|
|
|
|
class Device : public File {
|
|
protected:
|
|
enum class State {
|
|
Normal,
|
|
BeingRemoved,
|
|
};
|
|
|
|
public:
|
|
virtual ~Device() override;
|
|
|
|
MajorNumber major() const { return m_major; }
|
|
MinorNumber minor() const { return m_minor; }
|
|
|
|
virtual ErrorOr<NonnullOwnPtr<KString>> pseudo_path(OpenFileDescription const&) const override;
|
|
|
|
UserID uid() const { return m_uid; }
|
|
GroupID gid() const { return m_gid; }
|
|
|
|
virtual bool is_device() const override { return true; }
|
|
virtual void will_be_destroyed() override;
|
|
virtual void after_inserting();
|
|
void process_next_queued_request(Badge<AsyncDeviceRequest>, AsyncDeviceRequest const&);
|
|
|
|
template<typename AsyncRequestType, typename... Args>
|
|
ErrorOr<NonnullLockRefPtr<AsyncRequestType>> try_make_request(Args&&... args)
|
|
{
|
|
auto request = TRY(adopt_nonnull_lock_ref_or_enomem(new (nothrow) AsyncRequestType(*this, forward<Args>(args)...)));
|
|
SpinlockLocker lock(m_requests_lock);
|
|
bool was_empty = m_requests.is_empty();
|
|
TRY(m_requests.try_append(request));
|
|
if (was_empty)
|
|
request->do_start(move(lock));
|
|
return request;
|
|
}
|
|
|
|
protected:
|
|
Device(MajorNumber major, MinorNumber minor);
|
|
void set_uid(UserID uid) { m_uid = uid; }
|
|
void set_gid(GroupID gid) { m_gid = gid; }
|
|
|
|
void after_inserting_add_to_device_management();
|
|
void before_will_be_destroyed_remove_from_device_management();
|
|
|
|
virtual void after_inserting_add_symlink_to_device_identifier_directory() = 0;
|
|
virtual void before_will_be_destroyed_remove_symlink_from_device_identifier_directory() = 0;
|
|
|
|
// FIXME: These methods will be eventually removed after all nodes in /sys/dev/block/ and
|
|
// /sys/dev/char/ are symlinks.
|
|
virtual void after_inserting_add_to_device_identifier_directory() = 0;
|
|
virtual void before_will_be_destroyed_remove_from_device_identifier_directory() = 0;
|
|
|
|
private:
|
|
MajorNumber const m_major { 0 };
|
|
MinorNumber const m_minor { 0 };
|
|
UserID m_uid { 0 };
|
|
GroupID m_gid { 0 };
|
|
|
|
State m_state { State::Normal };
|
|
|
|
Spinlock m_requests_lock { LockRank::None };
|
|
DoublyLinkedList<LockRefPtr<AsyncDeviceRequest>> m_requests;
|
|
|
|
protected:
|
|
// FIXME: This pointer will be eventually removed after all nodes in /sys/dev/block/ and
|
|
// /sys/dev/char/ are symlinks.
|
|
LockRefPtr<SysFSDeviceComponent> m_sysfs_component;
|
|
|
|
LockRefPtr<SysFSSymbolicLinkDeviceComponent> m_symlink_sysfs_component;
|
|
LockRefPtr<SysFSDirectory> m_sysfs_device_directory;
|
|
};
|
|
|
|
}
|