Merge branch 'refactor-ext2-inode-size' into 'develop-BA-FS26'

Determine ext2 inode size depending on revision level, add const to several methods

See merge request teachos/kernel!34

3 files changed, 29 insertions, 9 deletions

diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index d22433f..18ef372 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -25,6 +25,9 @@ namespace kernel::filesystem::ext2
     constexpr size_t inline superblock_offset = base_block_size;
     constexpr uint16_t inline magic_number = 0xEF53;
 
+    constexpr uint32_t inline good_old_revision = 0;
+    constexpr uint32_t inline dynamic_revision = 1;
+
     constexpr uint32_t inline root_inode_number = 2;
 
     constexpr size_t inline direct_block_count = 12;
@@ -64,7 +67,13 @@ namespace kernel::filesystem::ext2
     @brief Gets the size of a block in the filesystem.
     @return The size of a block in bytes.
     */
-    auto get_block_size() -> size_t;
+    [[nodiscard]] auto get_block_size() const -> size_t;
+
+    /**
+    @brief Gets the revision level of the filesystem.
+    @return The revision level.
+    */
+    [[nodiscard]] auto get_revision_level() const -> size_t;
 
     /**
     @brief Maps an inode block index to a global block number.
@@ -72,14 +81,15 @@ namespace kernel::filesystem::ext2
     @param data The inode data.
     @return The global block number.
     */
-    auto map_inode_block_index_to_global_block_number(uint32_t inode_block_index, inode_data data) -> uint32_t;
+    [[nodiscard]] auto map_inode_block_index_to_global_block_number(uint32_t inode_block_index, inode_data data) const
+        -> uint32_t;
 
   private:
-    auto read_inode(uint32_t inode_number) -> kstd::shared_ptr<kernel::filesystem::ext2::inode>;
-    auto read_block_number_at_index(uint32_t block_number, uint32_t index) -> uint32_t;
+    [[nodiscard]] auto read_inode(uint32_t inode_number) const -> kstd::shared_ptr<kernel::filesystem::ext2::inode>;
+    [[nodiscard]] auto read_block_number_at_index(uint32_t block_number, uint32_t index) const -> uint32_t;
 
-    auto get_inode_size() -> size_t;
-    auto get_inode_block_count(inode_data const & data) -> uint32_t;
+    [[nodiscard]] auto get_inode_size() const -> size_t;
+    [[nodiscard]] auto get_inode_block_count(inode_data const & data) const -> uint32_t;
 
     superblock m_superblock{};
     kstd::vector<block_group_descriptor> m_block_group_descriptors;
diff --git a/kernel/include/kernel/filesystem/ext2/inode.hpp b/kernel/include/kernel/filesystem/ext2/inode.hpp
index b8f892a..000a5d8 100644
--- a/kernel/include/kernel/filesystem/ext2/inode.hpp
+++ b/kernel/include/kernel/filesystem/ext2/inode.hpp
@@ -20,7 +20,7 @@ namespace kernel::filesystem::ext2
   {
     uint16_t mode;
     uint16_t uid;
-    uint32_t size;  // TODO BA-FS26 signed?
+    uint32_t size;
     uint32_t atime;
     uint32_t ctime;
     uint32_t mtime;
@@ -45,7 +45,7 @@ namespace kernel::filesystem::ext2
     @param fs The ext2 filesystem that this inode belongs to.
     @param data The data associated with this inode, read from the disk.
     */
-    explicit inode(filesystem * fs, inode_data const & data);
+    explicit inode(filesystem const * fs, inode_data const & data);
 
     /**
     @brief Reads from the ext2 inode into a @p buffer, starting at the specified @p offset and for a given @p size.
@@ -90,8 +90,14 @@ namespace kernel::filesystem::ext2
      */
     [[nodiscard]] auto is_symbolic_link() const -> bool override;
 
+    /**
+    @brief Get the size of the file represented by this inode.
+    @return The size of the file in bytes.
+     */
+    [[nodiscard]] auto get_size() const -> size_t;
+
   private:
-    filesystem * m_filesystem;
+    filesystem const * m_filesystem;
     inode_data m_data{};
   };
 }  // namespace kernel::filesystem::ext2
diff --git a/kernel/include/kernel/test_support/filesystem/ext2.hpp b/kernel/include/kernel/test_support/filesystem/ext2.hpp
index 107e5a4..18cef1c 100644
--- a/kernel/include/kernel/test_support/filesystem/ext2.hpp
+++ b/kernel/include/kernel/test_support/filesystem/ext2.hpp
@@ -1,6 +1,7 @@
 #ifndef TEACHOS_KERNEL_TEST_SUPPORT_FILESYSTEM_EXT2_HPP
 #define TEACHOS_KERNEL_TEST_SUPPORT_FILESYSTEM_EXT2_HPP
 
+#include <kernel/filesystem/ext2/superblock.hpp>
 #include <kernel/test_support/devices/block_device.hpp>
 
 #include <cstddef>
@@ -12,6 +13,9 @@ namespace kernel::tests::filesystem::ext2
       -> void;
   auto write_u32(kernel::tests::devices::block_device & device, size_t offset, uint32_t value) -> void;
   auto setup_mock_ext2_layout(kernel::tests::devices::block_device & device) -> void;
+  auto setup_mock_ext2_layout(kernel::tests::devices::block_device & device,
+                              kernel::filesystem::ext2::superblock const & superblock) -> void;
+
 }  // namespace kernel::tests::filesystem::ext2
 
 #endif
\ No newline at end of file