Kernel: Start work on proper TmpFS in Heap instead of kmalloc memory

kernel/include/kernel/FS/TmpFS/Inode.h

@@ -0,0 +1,103 @@
+#pragma once
+
+#include <BAN/Iteration.h>
+#include <kernel/FS/Inode.h>
+#include <kernel/FS/TmpFS/Definitions.h>
+
+namespace Kernel
+{
+
+	class TmpFileSystem;
+
+	class TmpInode : public Inode
+	{
+	public:
+		virtual ino_t		ino()		const override final { return m_ino; }
+		virtual Mode		mode()		const override final { return Mode(m_inode_info.mode); }
+		virtual nlink_t		nlink()		const override final { return m_inode_info.nlink; }
+		virtual uid_t		uid()		const override final { return m_inode_info.uid; }
+		virtual gid_t		gid()		const override final { return m_inode_info.gid; }
+		virtual off_t		size()		const override final { return m_inode_info.size; }
+		virtual timespec	atime()		const override final { return m_inode_info.atime; }
+		virtual timespec	mtime()		const override final { return m_inode_info.mtime; }
+		virtual timespec	ctime()		const override final { return m_inode_info.ctime; }
+		virtual blksize_t	blksize()	const override final { return PAGE_SIZE; }
+		virtual blkcnt_t	blocks()	const override final { return m_inode_info.blocks; }
+		virtual dev_t		dev()		const override final { return 0; } // TODO
+		virtual dev_t		rdev()		const override final { return 0; } // TODO
+
+	public:
+		static BAN::ErrorOr<BAN::RefPtr<TmpInode>> create_from_existing(TmpFileSystem&, ino_t, const TmpInodeInfo&);
+
+	protected:
+		TmpInode(TmpFileSystem&, ino_t, const TmpInodeInfo&);
+
+		void sync();
+		void free_all_blocks();
+
+		size_t block_index(size_t data_block_index);
+		BAN::ErrorOr<size_t> block_index_with_allocation(size_t data_block_index);
+
+	protected:
+		TmpFileSystem& m_fs;
+		TmpInodeInfo m_inode_info;
+		const ino_t m_ino;
+
+		// has to be able to increase link count
+		friend class TmpDirectoryInode;
+	};
+
+	class TmpFileInode : public TmpInode
+	{
+	public:
+		static BAN::ErrorOr<BAN::RefPtr<TmpFileInode>> create(TmpFileSystem&, mode_t, uid_t, gid_t);
+		~TmpFileInode();
+
+	private:
+		TmpFileInode(TmpFileSystem&, ino_t, const TmpInodeInfo&);
+
+		friend class TmpInode;
+	};
+
+	class TmpSymlinkInode : public TmpInode
+	{
+	public:
+		~TmpSymlinkInode();
+
+	private:
+		TmpSymlinkInode(TmpFileSystem&, ino_t, const TmpInodeInfo&, BAN::StringView target);
+	};
+
+	template<typename F>
+	concept for_each_entry_callback = requires(F func, const TmpDirectoryEntry& entry)
+	{
+		requires BAN::is_same_v<decltype(func(entry)), BAN::Iteration>;
+	};
+
+	class TmpDirectoryInode : public TmpInode
+	{
+	public:
+		static BAN::ErrorOr<BAN::RefPtr<TmpDirectoryInode>> create_root(TmpFileSystem&, mode_t, uid_t, gid_t);
+		static BAN::ErrorOr<BAN::RefPtr<TmpDirectoryInode>> create_new(TmpFileSystem&, mode_t, uid_t, gid_t, TmpInode& parent);
+
+		~TmpDirectoryInode();
+
+	protected:
+		virtual BAN::ErrorOr<BAN::RefPtr<Inode>> find_inode_impl(BAN::StringView) override final;
+		virtual BAN::ErrorOr<void> list_next_inodes_impl(off_t, DirectoryEntryList*, size_t) override final;
+		virtual BAN::ErrorOr<void> create_file_impl(BAN::StringView, mode_t, uid_t, gid_t) override final;
+		virtual BAN::ErrorOr<void> create_directory_impl(BAN::StringView, mode_t, uid_t, gid_t) override final;
+		virtual BAN::ErrorOr<void> unlink_impl(BAN::StringView) override final;
+
+	private:
+		TmpDirectoryInode(TmpFileSystem&, ino_t, const TmpInodeInfo&);
+
+		BAN::ErrorOr<void> link_inode(TmpInode&, BAN::StringView);
+
+		template<for_each_entry_callback F>
+		void for_each_entry(F callback);
+
+		friend class TmpInode;
+	};
+
+}