Kernel/Devices: Defer creation of SysFS component after the constructor

Instead of doing so in the constructor, let's do immediately after the
constructor, so we can safely pass a reference of a Device, so the
SysFSDeviceComponent constructor can use that object to identify whether
it's a block device or a character device.
This allows to us to not hold a device in SysFSDeviceComponent with a
RefPtr.
Also, we also call the before_removing method in both SlavePTY::unref
and File::unref, so because Device has that method being overrided, it
can ensure the device is removed always cleanly.

Kernel/Devices/HID/HIDManagement.cpp

@@ -112,6 +112,7 @@ UNMAP_AFTER_INIT void HIDManagement::enumerate()
     m_i8042_controller->detect_devices();
     if (m_i8042_controller->mouse())
         m_hid_devices.append(m_i8042_controller->mouse().release_nonnull());
+
     if (m_i8042_controller->keyboard())
         m_hid_devices.append(m_i8042_controller->keyboard().release_nonnull());
 }

Kernel/Devices/HID/PS2KeyboardDevice.cpp

@@ -83,9 +83,11 @@ bool PS2KeyboardDevice::handle_irq(const RegisterState&)
 
 UNMAP_AFTER_INIT RefPtr<PS2KeyboardDevice> PS2KeyboardDevice::try_to_initialize(const I8042Controller& ps2_controller)
 {
-    auto device = adopt_ref(*new PS2KeyboardDevice(ps2_controller));
-    if (device->initialize())
-        return device;
+    auto keyboard_device_or_error = try_create_device<PS2KeyboardDevice>(ps2_controller);
+    // FIXME: Find a way to propagate errors
+    VERIFY(!keyboard_device_or_error.is_error());
+    if (keyboard_device_or_error.value()->initialize())
+        return keyboard_device_or_error.release_value();
     return nullptr;
 }
 

Kernel/Devices/HID/PS2KeyboardDevice.h

@@ -35,9 +35,10 @@ public:
         enable_irq();
     }
 
-private:
+    // FIXME: We expose this constructor to make try_create_device helper to work
     explicit PS2KeyboardDevice(const I8042Controller&);
 
+private:
     // ^IRQHandler
     virtual bool handle_irq(const RegisterState&) override;
 

Kernel/Devices/HID/PS2MouseDevice.cpp

@@ -174,9 +174,11 @@ void PS2MouseDevice::set_sample_rate(u8 rate)
 
 UNMAP_AFTER_INIT RefPtr<PS2MouseDevice> PS2MouseDevice::try_to_initialize(const I8042Controller& ps2_controller)
 {
-    auto device = adopt_ref(*new PS2MouseDevice(ps2_controller));
-    if (device->initialize())
-        return device;
+    auto mouse_device_or_error = try_create_device<PS2MouseDevice>(ps2_controller);
+    // FIXME: Find a way to propagate errors
+    VERIFY(!mouse_device_or_error.is_error());
+    if (mouse_device_or_error.value()->initialize())
+        return mouse_device_or_error.release_value();
     return nullptr;
 }
 

Kernel/Devices/HID/PS2MouseDevice.h

@@ -32,8 +32,10 @@ public:
         enable_irq();
     }
 
-protected:
+    // FIXME: We expose this constructor to make try_create_device helper to work
     explicit PS2MouseDevice(const I8042Controller&);
+
+protected:
     // ^IRQHandler
     virtual bool handle_irq(const RegisterState&) override;
 

Kernel/Devices/HID/VMWareMouseDevice.cpp

@@ -16,9 +16,11 @@ UNMAP_AFTER_INIT RefPtr<VMWareMouseDevice> VMWareMouseDevice::try_to_initialize(
         return {};
     if (!VMWareBackdoor::the()->vmmouse_is_absolute())
         return {};
-    auto device = adopt_ref(*new VMWareMouseDevice(ps2_controller));
-    if (device->initialize())
-        return device;
+    auto mouse_device_or_error = try_create_device<VMWareMouseDevice>(ps2_controller);
+    // FIXME: Find a way to propagate errors
+    VERIFY(!mouse_device_or_error.is_error());
+    if (mouse_device_or_error.value()->initialize())
+        return mouse_device_or_error.release_value();
     return {};
 }
 

Kernel/Devices/HID/VMWareMouseDevice.h

@@ -23,7 +23,7 @@ public:
     // ^I8042Device
     virtual void irq_handle_byte_read(u8 byte) override;
 
-private:
+    // FIXME: We expose this constructor to make try_create_device helper to work
     explicit VMWareMouseDevice(const I8042Controller&);
 };