Kernel/Devices: Remove required_mode and device_name methods

These methods are no longer needed because SystemServer is able to
populate the DevFS on its own.

Device absolute_path no longer assume a path to the /dev location,
because it really should not assume any path to a Device node.

Because StorageManagement still needs to know the storage name, we
declare a virtual method only for StorageDevices to override, but this
technique should really be removed later on.

Kernel/Devices/Device.cpp

@@ -51,8 +51,11 @@ Device::~Device()
 
 String Device::absolute_path() const
 {
-    // FIXME: Don't assume mount point for DevFs
-    return String::formatted("/dev/{}", device_name());
+    // FIXME: I assume we can't really provide a well known path in the kernel
+    // because this is a violation of abstraction layers between userland and the
+    // kernel, but maybe the whole name of "absolute_path" is just wrong as this
+    // is really not an "absolute_path".
+    return String::formatted("device:{},{}", major(), minor());
 }
 
 String Device::absolute_path(const OpenFileDescription&) const

Kernel/Devices/Device.h

@@ -37,9 +37,6 @@ public:
     UserID uid() const { return m_uid; }
     GroupID gid() const { return m_gid; }
 
-    virtual mode_t required_mode() const = 0;
-    virtual String device_name() const = 0;
-
     virtual bool is_device() const override { return true; }
 
     static void for_each(Function<void(Device&)>);

Kernel/Devices/FullDevice.h

@@ -16,10 +16,6 @@ public:
     static NonnullRefPtr<FullDevice> must_create();
     virtual ~FullDevice() override;
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0666; }
-    virtual String device_name() const override { return "full"; }
-
 private:
     FullDevice();
 

Kernel/Devices/HID/KeyboardDevice.h

@@ -33,14 +33,9 @@ public:
     // ^HIDDevice
     virtual Type instrument_type() const override { return Type::Keyboard; }
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0440; }
-
     // ^File
     virtual KResult ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg) override;
 
-    virtual String device_name() const override { return String::formatted("keyboard{}", minor()); }
-
     void update_modifier(u8 modifier, bool state)
     {
         if (state)

Kernel/Devices/HID/MouseDevice.h

@@ -31,11 +31,6 @@ public:
     // ^HIDDevice
     virtual Type instrument_type() const override { return Type::Mouse; }
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0440; }
-
-    virtual String device_name() const override { return String::formatted("mouse{}", minor()); }
-
 protected:
     MouseDevice();
     // ^CharacterDevice

Kernel/Devices/KCOVDevice.cpp

@@ -141,9 +141,4 @@ KResultOr<Memory::Region*> KCOVDevice::mmap(Process& process, OpenFileDescriptio
         range, *kcov_instance->vmobject(), offset, {}, prot, shared);
 }
 
-String KCOVDevice::device_name() const
-{
-    return "kcov"sv;
-}
-
 }

Kernel/Devices/KCOVDevice.h

@@ -25,10 +25,6 @@ public:
     KResultOr<Memory::Region*> mmap(Process&, OpenFileDescription&, Memory::VirtualRange const&, u64 offset, int prot, bool shared) override;
     KResultOr<NonnullRefPtr<OpenFileDescription>> open(int options) override;
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0660; }
-    virtual String device_name() const override;
-
 protected:
     virtual StringView class_name() const override { return "KCOVDevice"; }
 

Kernel/Devices/MemoryDevice.h

@@ -21,10 +21,6 @@ public:
 
     virtual KResultOr<Memory::Region*> mmap(Process&, OpenFileDescription&, Memory::VirtualRange const&, u64 offset, int prot, bool shared) override;
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0660; }
-    virtual String device_name() const override { return "mem"; };
-
 private:
     MemoryDevice();
     virtual StringView class_name() const override { return "MemoryDevice"; }

Kernel/Devices/NullDevice.h

@@ -19,10 +19,6 @@ public:
     static void initialize();
     static NullDevice& the();
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0666; }
-    virtual String device_name() const override { return "null"; }
-
 private:
     // ^CharacterDevice
     virtual KResultOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;

Kernel/Devices/RandomDevice.h

@@ -16,10 +16,6 @@ public:
     static NonnullRefPtr<RandomDevice> must_create();
     virtual ~RandomDevice() override;
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0666; }
-    virtual String device_name() const override { return "random"; }
-
 private:
     RandomDevice();
 

Kernel/Devices/SB16.h

@@ -34,10 +34,6 @@ public:
 
     virtual StringView purpose() const override { return class_name(); }
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0220; }
-    virtual String device_name() const override { return "audio"; }
-
     virtual KResult ioctl(OpenFileDescription&, unsigned, Userspace<void*>) override;
 
 private:

Kernel/Devices/SerialDevice.cpp

@@ -104,11 +104,6 @@ void SerialDevice::put_char(char ch)
     m_last_put_char_was_carriage_return = (ch == '\r');
 }
 
-String SerialDevice::device_name() const
-{
-    return String::formatted("ttyS{}", minor() - 64);
-}
-
 UNMAP_AFTER_INIT void SerialDevice::initialize()
 {
     set_interrupts(false);

Kernel/Devices/SerialDevice.h

@@ -102,10 +102,6 @@ public:
         DataReady = 0x01 << 0
     };
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0620; }
-    virtual String device_name() const override;
-
 private:
     friend class PCISerialDevice;
 

Kernel/Devices/ZeroDevice.h

@@ -16,10 +16,6 @@ public:
     static NonnullRefPtr<ZeroDevice> must_create();
     virtual ~ZeroDevice() override;
 
-    // ^Device
-    virtual mode_t required_mode() const override { return 0666; }
-    virtual String device_name() const override { return "zero"; }
-
 private:
     ZeroDevice();
     // ^CharacterDevice