diff options
Diffstat (limited to 'kernel/src/filesystem/ext2/filesystem.cpp')
| -rw-r--r-- | kernel/src/filesystem/ext2/filesystem.cpp | 247 |
1 files changed, 0 insertions, 247 deletions
diff --git a/kernel/src/filesystem/ext2/filesystem.cpp b/kernel/src/filesystem/ext2/filesystem.cpp deleted file mode 100644 index 3180a19a..00000000 --- a/kernel/src/filesystem/ext2/filesystem.cpp +++ /dev/null @@ -1,247 +0,0 @@ -#include <kernel/filesystem/ext2/filesystem.hpp> - -#include <kernel/filesystem/ext2/block_group_descriptor.hpp> -#include <kernel/filesystem/ext2/inode.hpp> -#include <kernel/filesystem/ext2/linked_directory_entry.hpp> -#include <kernel/filesystem/ext2/superblock.hpp> -#include <kernel/filesystem/filesystem.hpp> -#include <kernel/filesystem/inode.hpp> -#include <kernel/filesystem/type.hpp> - -#include <kstd/memory> -#include <kstd/unikstd.h> -#include <kstd/vector> - -#include <array> -#include <cstddef> -#include <cstdint> -#include <string_view> - -namespace kernel::filesystem::ext2 -{ - - struct type final : kernel::filesystem::type - { - [[nodiscard]] auto name() const noexcept -> std::string_view override - { - return "ext2"; - } - - [[nodiscard]] auto requires_device() const noexcept -> bool override - { - return true; - } - - [[nodiscard]] auto make_instance() const -> kstd::shared_ptr<kernel::filesystem::filesystem> override - { - return kstd::make_shared<filesystem>(); - } - }; - - [[gnu::used]] - constexpr auto registration = type_registration<type>{}; - - auto filesystem::mount(kstd::shared_ptr<kernel::filesystem::inode> const & backing_inode) -> operation_result - { - kernel::filesystem::filesystem::mount(backing_inode); - - m_backing_inode->read(&m_superblock, constants::superblock_offset, sizeof(m_superblock)); - - if (m_superblock.magic != constants::magic_number) - { - return operation_result::invalid_magic_number; - } - - auto const blocks_per_group = m_superblock.blocks_per_group; - auto const num_block_groups = (m_superblock.blocks_count + blocks_per_group - 1) / blocks_per_group; - - m_block_group_descriptors = kstd::vector<block_group_descriptor>(num_block_groups); - - m_backing_inode->read(m_block_group_descriptors.data(), block_group_descriptor_table_offset(), - num_block_groups * sizeof(block_group_descriptor)); - - m_root_inode = read_inode(constants::root_inode_number); - - if (!m_root_inode || !m_root_inode->is_directory()) - { - return operation_result::invalid_root_inode; - } - return operation_result::success; - } - - auto filesystem::lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name) const - -> kstd::shared_ptr<kernel::filesystem::inode> - { - if (!parent || !parent->is_directory()) - { - return nullptr; - } - - auto * ext2_parent = static_cast<inode *>(parent.get()); - if (!ext2_parent) - { - return nullptr; - } - - auto const & inode_data = ext2_parent->data(); - kstd::vector<uint8_t> buffer(block_size()); - - for (uint32_t i = 0; i < inode_block_count(inode_data); ++i) - { - auto const global_block_number = map_inode_block_index_to_global_block_number(i, inode_data); - auto const block_offset = global_block_number * block_size(); - m_backing_inode->read(buffer.data(), block_offset, block_size()); - - auto const * entry = reinterpret_cast<linked_directory_entry const *>(buffer.data()); - auto bytes_read = 0uz; - - while (bytes_read < block_size() && entry->inode != 0) - { - auto const entry_name = std::string_view{entry->name.data(), entry->name_len}; - if (entry_name == name) - { - return read_inode(entry->inode); - } - - bytes_read += entry->rec_len; - entry = reinterpret_cast<linked_directory_entry const *>(buffer.data() + bytes_read); - } - } - - return nullptr; - } - - auto filesystem::read_inode(uint32_t inode_number) const -> kstd::shared_ptr<inode> - { - auto const inodes_per_group = m_superblock.inodes_per_group; - auto const block_group_index = (inode_number - 1) / inodes_per_group; - auto const inode_index_within_group = (inode_number - 1) % inodes_per_group; - - if (block_group_index >= m_block_group_descriptors.size()) - { - return nullptr; - } - - auto const & block_group_descriptor = m_block_group_descriptors.at(block_group_index); - auto const inode_table_start_block = block_group_descriptor.inode_table; - auto const inode_table_offset = static_cast<size_t>(inode_table_start_block) * block_size(); - auto const inode_offset = inode_table_offset + inode_index_within_group * inode_size(); - - auto new_inode_data = inode_data{}; - m_backing_inode->read(&new_inode_data, inode_offset, sizeof(inode_data)); - - return kstd::make_shared<inode>(this, new_inode_data); - } - - auto filesystem::indirect_levels() const -> std::array<indirect_level, 3> - { - return { - {{constants::singly_indirect_block_index, block_numbers_per_singly_indirect_block()}, - {constants::doubly_indirect_block_index, block_numbers_per_doubly_indirect_block()}, - {constants::triply_indirect_block_index, block_numbers_per_triply_indirect_block()}} - }; - } - - auto filesystem::map_inode_block_index_to_global_block_number(size_t inode_block_index, inode_data data) const - -> kstd::ssize_t - { - if (inode_block_index < constants::direct_block_count) - { - return data.block.at(inode_block_index); - } - - inode_block_index -= constants::direct_block_count; - - for (auto const & level : indirect_levels()) - { - if (inode_block_index >= level.capacity) - { - inode_block_index -= level.capacity; - continue; - } - - auto block_number = data.block[level.slot_index]; - if (block_number == 0) - { - return 0; - } - - for (auto stride = level.capacity / block_numbers_per_block();; stride /= block_numbers_per_block()) - { - auto const idx = inode_block_index / stride; - inode_block_index %= stride; - - block_number = read_block_number_at_index(block_number, idx); - if (block_number == 0) - { - return 0; - } - - if (stride == 1) - { - break; - } - } - - return block_number; - } - - return -1; - } - - auto filesystem::read_block_number_at_index(uint32_t block_number, size_t index) const -> uint32_t - { - uint32_t block_number_buffer = 0; - - auto const block_start_offset = block_number * block_size(); - auto const number_start_address = block_start_offset + index * sizeof(uint32_t); - m_backing_inode->read(&block_number_buffer, number_start_address, sizeof(uint32_t)); - - return block_number_buffer; - } - - auto filesystem::block_numbers_per_block() const -> size_t - { - return block_size() / sizeof(uint32_t); - } - - auto filesystem::block_numbers_per_singly_indirect_block() const -> size_t - { - return block_numbers_per_block(); - } - - auto filesystem::block_numbers_per_doubly_indirect_block() const -> size_t - { - return block_numbers_per_singly_indirect_block() * block_numbers_per_block(); - } - - auto filesystem::block_numbers_per_triply_indirect_block() const -> size_t - { - return block_numbers_per_doubly_indirect_block() * block_numbers_per_block(); - } - - auto filesystem::block_size() const -> size_t - { - return constants::base_block_size << m_superblock.log_block_size; - } - - auto filesystem::revision_level() const -> uint32_t - { - return m_superblock.rev_level; - } - - auto filesystem::inode_size() const -> uint16_t - { - return revision_level() == constants::good_old_revision ? 128 : m_superblock.inode_size; - } - - auto filesystem::inode_block_count(inode_data const & data) const -> uint32_t - { - return data.blocks / (2 << m_superblock.log_block_size); - } - - auto filesystem::block_group_descriptor_table_offset() const -> size_t - { - return block_size() == 1024 ? 2 * block_size() : block_size(); - } -} // namespace kernel::filesystem::ext2 |