Kernel: Make ext2 block buffers page aligned

kernel/include/kernel/FS/Ext2/FileSystem.h

@@ -28,7 +28,7 @@ namespace Kernel
 			BAN_NON_COPYABLE(BlockBufferWrapper);
 
 		public:
-			BlockBufferWrapper(BAN::Span<uint8_t> buffer, void (*callback)(void*, const uint8_t*), void* argument)
+			BlockBufferWrapper(BAN::ByteSpan buffer, void (*callback)(void*, const uint8_t*), void* argument)
 				: m_buffer(buffer)
 				, m_callback(callback)
 				, m_argument(argument)
@@ -60,13 +60,13 @@ namespace Kernel
 			const uint8_t* data() const { return m_buffer.data(); }
 
 			BAN::ByteSpan span() { return m_buffer; }
-			BAN::ConstByteSpan span() const { return m_buffer.as_const(); }
+			BAN::ConstByteSpan span() const { return m_buffer; }
 
 			uint8_t& operator[](size_t index) { return m_buffer[index]; }
 			uint8_t operator[](size_t index) const { return m_buffer[index]; }
 
 		private:
-			BAN::Span<uint8_t> m_buffer;
+			BAN::ByteSpan m_buffer;
 			void (*m_callback)(void*, const uint8_t*);
 			void* m_argument;
 		};
@@ -128,7 +128,7 @@ namespace Kernel
 		private:
 			struct BlockBuffer
 			{
-				BAN::Vector<uint8_t> buffer;
+				BAN::ByteSpan buffer;
 				bool used { false };
 			};
 
@@ -144,6 +144,7 @@ namespace Kernel
 
 			Mutex m_buffer_mutex;
 			ThreadBlocker m_buffer_blocker;
+			BAN::UniqPtr<VirtualRange> m_buffer_data;
 			BAN::Array<BlockBuffer, max_threads * max_buffers_per_thread> m_buffers;
 			BAN::Array<ThreadInfo, max_threads> m_thread_infos;
 		};

kernel/kernel/FS/Ext2/FileSystem.cpp

@@ -624,7 +624,7 @@ namespace Kernel
 				continue;
 			buffer.used = true;
 			return Ext2FS::BlockBufferWrapper {
-				buffer.buffer.span(),
+				buffer.buffer,
 				[](void* self, const uint8_t* buffer) { static_cast<BlockBufferManager*>(self)->destroy_callback(buffer); },
 				this
 			};
@@ -635,11 +635,23 @@ namespace Kernel
 
 	BAN::ErrorOr<void> Ext2FS::BlockBufferManager::initialize(size_t block_size)
 	{
-		for (auto& buffer : m_buffers)
+		m_buffer_data = TRY(VirtualRange::create_to_vaddr_range(
+			PageTable::kernel(),
+			{ KERNEL_OFFSET, BAN::numeric_limits<vaddr_t>::max() },
+			block_size * m_buffers.size(),
+			PageTable::ReadWrite | PageTable::Present,
+			false
+		));
+
+		auto buffer_data_span = BAN::ByteSpan { reinterpret_cast<uint8_t*>(m_buffer_data->vaddr()), m_buffer_data->size() };
+		for (size_t i = 0; i < m_buffers.size(); i++)
 		{
-			TRY(buffer.buffer.resize(block_size));
-			buffer.used = false;
+			m_buffers[i] = {
+				.buffer = buffer_data_span.slice(i * block_size, block_size),
+				.used = false,
+			};
 		}
+
 		return {};
 	}