diff options
Diffstat (limited to 'kernel/src/filesystem/ext2')
| -rw-r--r-- | kernel/src/filesystem/ext2/filesystem.cpp | 127 |
1 files changed, 63 insertions, 64 deletions
diff --git a/kernel/src/filesystem/ext2/filesystem.cpp b/kernel/src/filesystem/ext2/filesystem.cpp index df5b4c4..3180a19 100644 --- a/kernel/src/filesystem/ext2/filesystem.cpp +++ b/kernel/src/filesystem/ext2/filesystem.cpp @@ -6,17 +6,41 @@ #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> -#include <unistd.h> 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); @@ -109,85 +133,60 @@ namespace kernel::filesystem::ext2 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 - -> ssize_t + -> 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; - if (inode_block_index < block_numbers_per_singly_indirect_block()) - { - auto const singly_indirect_block_number = data.block.at(constants::singly_indirect_block_index); - return read_singly_indirect_block_number(singly_indirect_block_number, inode_block_index); - } - inode_block_index -= block_numbers_per_singly_indirect_block(); - - if (inode_block_index < block_numbers_per_doubly_indirect_block()) - { - auto const doubly_indirect_block_number = data.block.at(constants::doubly_indirect_block_index); - return read_doubly_indirect_block_number(doubly_indirect_block_number, inode_block_index); - } - inode_block_index -= block_numbers_per_doubly_indirect_block(); - - if (inode_block_index < block_numbers_per_triply_indirect_block()) - { - auto const triply_indirect_block_number = data.block.at(constants::triply_indirect_block_index); - return read_triply_indirect_block_number(triply_indirect_block_number, inode_block_index); - } - - return -1; - } + inode_block_index -= constants::direct_block_count; - auto filesystem::read_singly_indirect_block_number(uint32_t singly_indirect_block_number, - size_t block_index_in_singly_indirect_block) const -> size_t - { - if (singly_indirect_block_number == 0) + for (auto const & level : indirect_levels()) { - return 0; - } - - return read_block_number_at_index(singly_indirect_block_number, block_index_in_singly_indirect_block); - } + if (inode_block_index >= level.capacity) + { + inode_block_index -= level.capacity; + continue; + } - auto filesystem::read_doubly_indirect_block_number(uint32_t doubly_indirect_block_number, - size_t block_index_in_doubly_indirect_block) const -> size_t - { - if (doubly_indirect_block_number == 0) - { - return 0; - } + auto block_number = data.block[level.slot_index]; + if (block_number == 0) + { + return 0; + } - auto const singly_indirect_block_index_in_doubly_indirect_block = - block_index_in_doubly_indirect_block / block_numbers_per_singly_indirect_block(); - auto const block_index_in_singly_indirect_block = - block_index_in_doubly_indirect_block % block_numbers_per_singly_indirect_block(); + 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; - auto const singly_indirect_block_number = - read_block_number_at_index(doubly_indirect_block_number, singly_indirect_block_index_in_doubly_indirect_block); + block_number = read_block_number_at_index(block_number, idx); + if (block_number == 0) + { + return 0; + } - return read_singly_indirect_block_number(singly_indirect_block_number, block_index_in_singly_indirect_block); - } + if (stride == 1) + { + break; + } + } - auto filesystem::read_triply_indirect_block_number(uint32_t triply_indirect_block_number, - size_t block_index_in_triply_indirect_block) const -> size_t - { - if (triply_indirect_block_number == 0) - { - return 0; + return block_number; } - auto const doubly_indirect_block_index_in_triply_indirect_block = - block_index_in_triply_indirect_block / block_numbers_per_doubly_indirect_block(); - auto const block_index_in_doubly_indirect_block = - block_index_in_triply_indirect_block % block_numbers_per_doubly_indirect_block(); - - auto const doubly_indirect_block_number = - read_block_number_at_index(triply_indirect_block_number, doubly_indirect_block_index_in_triply_indirect_block); - - return read_doubly_indirect_block_number(doubly_indirect_block_number, block_index_in_doubly_indirect_block); + return -1; } auto filesystem::read_block_number_at_index(uint32_t block_number, size_t index) const -> uint32_t |