Kernel/SysFS: Prevent allocation for component name during construction

Instead, allocate before constructing the object and pass NonnullOwnPtr
of KString to the object if needed. Some classes can determine their
names as they have a known attribute to look for or have a static name.

1 files changed, 9 insertions, 6 deletions

diff --git a/Kernel/Devices/Device.cpp b/Kernel/Devices/Device.cpp
index 766086ce83..3e32f85f16 100644
--- a/Kernel/Devices/Device.cpp
+++ b/Kernel/Devices/Device.cpp
@@ -15,11 +15,14 @@ namespace Kernel {
 
 NonnullRefPtr<SysFSDeviceComponent> SysFSDeviceComponent::must_create(Device const& device)
 {
-    return adopt_ref_if_nonnull(new SysFSDeviceComponent(device)).release_nonnull();
+    // FIXME: Handle allocation failure gracefully
+    auto device_name = MUST(KString::try_create(String::formatted("{}:{}", device.major(), device.minor())));
+    return adopt_ref_if_nonnull(new SysFSDeviceComponent(move(device_name), device)).release_nonnull();
 }
-SysFSDeviceComponent::SysFSDeviceComponent(Device const& device)
-    : SysFSComponent(String::formatted("{}:{}", device.major(), device.minor()))
+SysFSDeviceComponent::SysFSDeviceComponent(NonnullOwnPtr<KString> major_minor_formatted_device_name, Device const& device)
+    : SysFSComponent()
     , m_block_device(device.is_block_device())
+    , m_major_minor_formatted_device_name(move(major_minor_formatted_device_name))
 {
     VERIFY(device.is_block_device() || device.is_character_device());
 }
@@ -32,7 +35,7 @@ UNMAP_AFTER_INIT NonnullRefPtr<SysFSDevicesDirectory> SysFSDevicesDirectory::mus
     return devices_directory;
 }
 SysFSDevicesDirectory::SysFSDevicesDirectory(SysFSRootDirectory const& root_directory)
-    : SysFSDirectory("dev"sv, root_directory)
+    : SysFSDirectory(root_directory)
 {
 }
 
@@ -41,7 +44,7 @@ NonnullRefPtr<SysFSBlockDevicesDirectory> SysFSBlockDevicesDirectory::must_creat
     return adopt_ref_if_nonnull(new SysFSBlockDevicesDirectory(devices_directory)).release_nonnull();
 }
 SysFSBlockDevicesDirectory::SysFSBlockDevicesDirectory(SysFSDevicesDirectory const& devices_directory)
-    : SysFSDirectory("block"sv, devices_directory)
+    : SysFSDirectory(devices_directory)
 {
 }
 
@@ -79,7 +82,7 @@ NonnullRefPtr<SysFSCharacterDevicesDirectory> SysFSCharacterDevicesDirectory::mu
     return adopt_ref_if_nonnull(new SysFSCharacterDevicesDirectory(devices_directory)).release_nonnull();
 }
 SysFSCharacterDevicesDirectory::SysFSCharacterDevicesDirectory(SysFSDevicesDirectory const& devices_directory)
-    : SysFSDirectory("char"sv, devices_directory)
+    : SysFSDirectory(devices_directory)
 {
 }
 ErrorOr<void> SysFSCharacterDevicesDirectory::traverse_as_directory(FileSystemID fsid, Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)> callback) const