Method create_inode

kernel/kernel/FS/Ext2/FileSystem.cpp:200–276

	}

	BAN::ErrorOr<uint32_t> Ext2FS::create_inode(const Ext2::Inode& ext2_inode)
	{
		auto bgd_buffer = TRY(m_buffer_manager.get_buffer());
		auto inode_bitmap = TRY(m_buffer_manager.get_buffer());

		LockGuard _(m_mutex);

		ASSERT(ext2_inode.size == 0);

		if (m_superblock.free_inodes_count == 0)
			return BAN::Error::from_errno(ENOSPC);

		const uint32_t block_size = this->block_size();

		uint32_t current_group = -1;
		BlockLocation bgd_location {};
		Ext2::BlockGroupDescriptor* bgd = nullptr;

		for (uint32_t ino = superblock().first_ino; ino <= superblock().inodes_count; ino++)
		{
			const uint32_t ino_group = (ino - 1) / superblock().inodes_per_group;
			const uint32_t ino_index = (ino - 1) % superblock().inodes_per_group;

			if (ino_group != current_group)
			{
				current_group = ino_group;

				bgd_location = locate_block_group_descriptior(current_group);
				TRY(read_block(bgd_location.block, bgd_buffer));

				bgd = (Ext2::BlockGroupDescriptor*)(bgd_buffer.data() + bgd_location.offset);
				if (bgd->free_inodes_count == 0)
				{
					ino = superblock().first_ino + (current_group + 1) * superblock().inodes_per_group - 1;
					continue;
				}

				TRY(read_block(bgd->inode_bitmap, inode_bitmap));
			}

			const uint32_t ino_bitmap_byte = ino_index / 8;
			const uint32_t ino_bitmap_bit  = ino_index % 8;
			if (inode_bitmap[ino_bitmap_byte] & (1 << ino_bitmap_bit))
				continue;

			inode_bitmap[ino_bitmap_byte] |= 1 << ino_bitmap_bit;
			TRY(write_block(bgd->inode_bitmap, inode_bitmap));

			bgd->free_inodes_count--;
			if (Inode::Mode(ext2_inode.mode).ifdir())
				bgd->used_dirs_count++;
			TRY(write_block(bgd_location.block, bgd_buffer));

			const uint32_t inode_table_offset = ino_index * superblock().inode_size;
			const BlockLocation inode_location {
				.block  = inode_table_offset / block_size + bgd->inode_table,
				.offset = inode_table_offset % block_size
			};