3 files changed, 94 insertions, 49 deletions

diff --git a/kernel/src/filesystem/ext2/filesystem.cpp b/kernel/src/filesystem/ext2/filesystem.cpp
index 41572ee..47e54fe 100644
--- a/kernel/src/filesystem/ext2/filesystem.cpp
+++ b/kernel/src/filesystem/ext2/filesystem.cpp
@@ -16,19 +16,6 @@
 
 namespace kernel::filesystem::ext2
 {
-  namespace
-  {
-    auto S_ISREG(uint16_t mode) -> bool
-    {
-      return (mode & constants::mode_mask) == constants::mode_regular;
-    }
-
-    auto S_ISDIR(uint16_t mode) -> bool
-    {
-      return (mode & constants::mode_mask) == constants::mode_directory;
-    }
-  }  // namespace
-
   auto filesystem::mount(kstd::shared_ptr<kernel::filesystem::inode> const & backing_inode) -> operation_result
   {
     kernel::filesystem::filesystem::mount(backing_inode);
@@ -74,7 +61,7 @@ namespace kernel::filesystem::ext2
     }
 
     auto const block_size = get_block_size();
-    auto const & inode_data = ext2_parent->m_data;
+    auto const & inode_data = ext2_parent->data();
     kstd::vector<uint8_t> buffer(block_size);
 
     for (uint32_t i = 0; i < get_inode_block_count(inode_data); ++i)
@@ -119,25 +106,10 @@ namespace kernel::filesystem::ext2
     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 * get_inode_size();
 
-    auto new_inode = kstd::make_shared<inode>(this);
-    m_backing_inode->read(&new_inode->m_data, inode_offset, sizeof(inode_data));
-
-    // TODO BA-FS26 improve inode_kind really needed? or just map it to the mode bits?
-    if (S_ISREG(new_inode->m_data.mode))
-    {
-      new_inode->m_kind = inode::inode_kind::regular;
-    }
-    else if (S_ISDIR(new_inode->m_data.mode))
-    {
-      new_inode->m_kind = inode::inode_kind::directory;
-    }
-    else
-    {
-      // TODO BA-FS26 really correct??
-      return nullptr;
-    }
+    auto new_inode_data = inode_data{};
+    m_backing_inode->read(&new_inode_data, inode_offset, sizeof(inode_data));
 
-    return new_inode;
+    return kstd::make_shared<inode>(this, new_inode_data);
   }
 
   auto filesystem::map_inode_block_index_to_global_block_number(uint32_t inode_block_index, inode_data data) -> uint32_t
diff --git a/kernel/src/filesystem/ext2/inode.cpp b/kernel/src/filesystem/ext2/inode.cpp
index c45c41e..1914c70 100644
--- a/kernel/src/filesystem/ext2/inode.cpp
+++ b/kernel/src/filesystem/ext2/inode.cpp
@@ -5,15 +5,17 @@
 
 #include <kapi/system.hpp>
 
+#include <kstd/cstring>
+
 #include <algorithm>
 #include <cstddef>
 #include <cstdint>
 
 namespace kernel::filesystem::ext2
 {
-  inode::inode(filesystem * fs)
-      : kernel::filesystem::inode(inode_kind::regular)
-      , m_filesystem(fs)
+  inode::inode(filesystem * fs, inode_data const & data)
+      : m_filesystem(fs)
+      , m_data(data)
   {
     if (!m_filesystem)
     {
@@ -23,6 +25,17 @@ namespace kernel::filesystem::ext2
 
   auto inode::read(void * buffer, size_t offset, size_t size) const -> size_t
   {
+    // TODO BA-FS26 use revision 1 size
+    auto const max_readable = static_cast<size_t>(m_data.size) - offset;
+    auto const requested_size = std::min(size, max_readable);
+
+    if (is_symbolic_link() && m_data.size <= sizeof(m_data.block))
+    {
+      auto inline_target = reinterpret_cast<uint8_t const *>(m_data.block.data());
+      kstd::libc::memcpy(static_cast<uint8_t *>(buffer), inline_target + offset, requested_size);
+      return requested_size;
+    }
+
     auto block_index = offset / m_filesystem->get_block_size();
     auto in_block_offset = offset % m_filesystem->get_block_size();
 
@@ -40,7 +53,8 @@ namespace kernel::filesystem::ext2
 
       auto const block_start_offset = block_number * m_filesystem->get_block_size();
       auto const read_offset = block_start_offset + in_block_offset;
-      auto const bytes_to_read = std::min(size - bytes_read, m_filesystem->get_block_size() - in_block_offset);
+      auto const bytes_to_read =
+          std::min(requested_size - bytes_read, m_filesystem->get_block_size() - in_block_offset);
 
       bytes_read +=
           m_filesystem->backing_inode()->read(static_cast<uint8_t *>(buffer) + bytes_read, read_offset, bytes_to_read);
@@ -57,4 +71,24 @@ namespace kernel::filesystem::ext2
     kapi::system::panic("[EXT2] inode::write is not implemented yet");
     return 0;
   }
+
+  [[nodiscard]] auto inode::data() const -> inode_data const &
+  {
+    return m_data;
+  }
+
+  auto inode::is_regular() const -> bool
+  {
+    return (m_data.mode & constants::mode_mask) == constants::mode_regular;
+  }
+
+  auto inode::is_directory() const -> bool
+  {
+    return (m_data.mode & constants::mode_mask) == constants::mode_directory;
+  }
+
+  auto inode::is_symbolic_link() const -> bool
+  {
+    return (m_data.mode & constants::mode_mask) == constants::mode_symbolic_link;
+  }
 }  // namespace kernel::filesystem::ext2
diff --git a/kernel/src/filesystem/ext2/inode.tests.cpp b/kernel/src/filesystem/ext2/inode.tests.cpp
index 4d61790..49ba21b 100644
--- a/kernel/src/filesystem/ext2/inode.tests.cpp
+++ b/kernel/src/filesystem/ext2/inode.tests.cpp
@@ -23,13 +23,50 @@ SCENARIO("Ext2 inode initialization and properties", "[filesystem][ext2][inode]"
   GIVEN("an ext2 filesystem")
   {
     auto fs = kernel::filesystem::ext2::filesystem{};
+    auto data = kernel::filesystem::ext2::inode_data{};
 
-    THEN("the inode is initialized and has the kind regular")
+    THEN("the inode is initialized with regular file mode in data and has the kind regular")
     {
-      auto inode = kernel::filesystem::ext2::inode{&fs};
+      data.mode = kernel::filesystem::ext2::constants::mode_regular;
+      auto inode = kernel::filesystem::ext2::inode(&fs, data);
+
       REQUIRE(inode.is_regular());
-      REQUIRE(!inode.is_directory());
-      REQUIRE(!inode.is_device());
+      REQUIRE_FALSE(inode.is_directory());
+      REQUIRE_FALSE(inode.is_device());
+      REQUIRE_FALSE(inode.is_symbolic_link());
+    }
+
+    THEN("the inode is initialized with directory mode in data and has the kind directory")
+    {
+      data.mode = kernel::filesystem::ext2::constants::mode_directory;
+      auto inode = kernel::filesystem::ext2::inode(&fs, data);
+
+      REQUIRE_FALSE(inode.is_regular());
+      REQUIRE(inode.is_directory());
+      REQUIRE_FALSE(inode.is_device());
+      REQUIRE_FALSE(inode.is_symbolic_link());
+    }
+
+    THEN("the inode is initialized with symbolic link mode in data and has the kind symbolic link")
+    {
+      data.mode = kernel::filesystem::ext2::constants::mode_symbolic_link;
+      auto inode = kernel::filesystem::ext2::inode(&fs, data);
+
+      REQUIRE_FALSE(inode.is_regular());
+      REQUIRE_FALSE(inode.is_directory());
+      REQUIRE_FALSE(inode.is_device());
+      REQUIRE(inode.is_symbolic_link());
+    }
+
+    THEN("the inode is initialized with zero mode in data and has no specific kind")
+    {
+      data.mode = 0;
+      auto inode = kernel::filesystem::ext2::inode(&fs, data);
+
+      REQUIRE_FALSE(inode.is_regular());
+      REQUIRE_FALSE(inode.is_directory());
+      REQUIRE_FALSE(inode.is_device());
+      REQUIRE_FALSE(inode.is_symbolic_link());
     }
   }
 
@@ -37,7 +74,7 @@ SCENARIO("Ext2 inode initialization and properties", "[filesystem][ext2][inode]"
   {
     THEN("constructing an inode with a null filesystem pointer panics")
     {
-      REQUIRE_THROWS_AS(kernel::filesystem::ext2::inode{nullptr}, kernel::tests::cpu::halt);
+      REQUIRE_THROWS_AS(kernel::filesystem::ext2::inode(nullptr, {}), kernel::tests::cpu::halt);
     }
   }
 }
@@ -102,9 +139,10 @@ SCENARIO("Ext2 inode read stops when block mapping resolves to zero", "[filesyst
     auto fs = kernel::filesystem::ext2::filesystem{};
     REQUIRE(fs.mount(dev_inode) == kernel::filesystem::filesystem::operation_result::success);
 
-    auto inode = kernel::filesystem::ext2::inode{&fs};
-    inode.m_data.blocks = 2;
-    inode.m_data.block[0] = 0;
+    auto data = kernel::filesystem::ext2::inode_data{};
+    data.blocks = 2;
+    data.block[0] = 0;
+    auto inode = kernel::filesystem::ext2::inode{&fs, data};
 
     auto buffer = kstd::vector<std::byte>(32, std::byte{0xAB});
 
@@ -130,12 +168,13 @@ SCENARIO("Ext2 inode read across block boundaries", "[filesystem][ext2][inode]")
     auto fs = kernel::filesystem::ext2::filesystem{};
     REQUIRE(fs.mount(dev_inode) == kernel::filesystem::filesystem::operation_result::success);
 
-    auto inode = kernel::filesystem::ext2::inode{&fs};
-    inode.m_data.blocks = 2;
-    inode.m_data.block[0] = 20;
+    auto inode_data = kernel::filesystem::ext2::inode_data{};
+    inode_data.blocks = 2;
+    inode_data.block[0] = 20;
     kernel::tests::filesystem::ext2::write_bytes(*device, 21 * block_size - 6, "Hello ", 6);
-    inode.m_data.block[1] = 21;
+    inode_data.block[1] = 21;
     kernel::tests::filesystem::ext2::write_bytes(*device, 21 * block_size, "World!", 6);
+    auto inode = kernel::filesystem::ext2::inode{&fs, inode_data};
 
     auto buffer = kstd::vector<std::byte>(12, std::byte{0x00});
 
@@ -155,7 +194,7 @@ SCENARIO("Ext2 inode write is not implemented", "[filesystem][ext2][inode]")
   GIVEN("an ext2 inode")
   {
     auto fs = kernel::filesystem::ext2::filesystem{};
-    auto inode = kernel::filesystem::ext2::inode{&fs};
+    auto inode = kernel::filesystem::ext2::inode{&fs, kernel::filesystem::ext2::inode_data{}};
 
     THEN("writing to the inode panics")
     {