8 files changed, 92 insertions, 7 deletions
diff --git a/kernel/filesystem/CMakeLists.txt b/kernel/filesystem/CMakeLists.txt
index 19f1be1..bb2090a 100644
--- a/kernel/filesystem/CMakeLists.txt
+++ b/kernel/filesystem/CMakeLists.txt
@@ -25,6 +25,7 @@ target_sources("kernel_filesystem" PUBLIC
     "include/filesystem/file.hpp"
     "include/filesystem/filesystem.hpp"
     "include/filesystem/inode_file.hpp"
+    "include/filesystem/inode_metadata.hpp"
     "include/filesystem/inode.hpp"
     "include/filesystem/mount.hpp"
     "include/filesystem/open_file_description.hpp"
diff --git a/kernel/filesystem/include/filesystem/ext2/ext2_filesystem.hpp b/kernel/filesystem/include/filesystem/ext2/ext2_filesystem.hpp
index 91ba14a..cba2192 100644
--- a/kernel/filesystem/include/filesystem/ext2/ext2_filesystem.hpp
+++ b/kernel/filesystem/include/filesystem/ext2/ext2_filesystem.hpp
@@ -3,12 +3,16 @@
 
 #include "devices/device.hpp"
 #include "filesystem/filesystem.hpp"
+#include "filesystem/inode.hpp"
+
+#include <string_view>
 
 namespace filesystem::ext2
 {
   struct ext2_filesystem : filesystem
   {
     auto mount(devices::device * device) -> int override;
+    auto lookup(inode const & parent, std::string_view name) -> inode * override;
 
   private:
     devices::device * m_device{};
diff --git a/kernel/filesystem/include/filesystem/filesystem.hpp b/kernel/filesystem/include/filesystem/filesystem.hpp
index 2077ed6..8deb336 100644
--- a/kernel/filesystem/include/filesystem/filesystem.hpp
+++ b/kernel/filesystem/include/filesystem/filesystem.hpp
@@ -4,6 +4,8 @@
 #include "devices/device.hpp"
 #include "filesystem/inode.hpp"
 
+#include <string_view>
+
 namespace filesystem
 {
   struct filesystem
@@ -11,8 +13,10 @@ namespace filesystem
     virtual ~filesystem() = default;
 
     virtual auto mount(devices::device * device) -> int = 0;
+    virtual auto lookup(inode const & parent, std::string_view name) -> inode * = 0;
 
-    [[nodiscard]] auto root_inode() const -> inode const &;
+    [[nodiscard]] auto root_inode() -> inode *;
+    [[nodiscard]] auto root_inode() const -> inode const *;
 
   protected:
     inode m_root_inode{};  // TODO BA-FS26 set during mount?
diff --git a/kernel/filesystem/include/filesystem/inode.hpp b/kernel/filesystem/include/filesystem/inode.hpp
index eb8440f..bceabb6 100644
--- a/kernel/filesystem/include/filesystem/inode.hpp
+++ b/kernel/filesystem/include/filesystem/inode.hpp
@@ -2,6 +2,7 @@
 #define TEACH_OS_KERNEL_FILESYSTEM_INODE_HPP
 
 #include "devices/device.hpp"
+#include "filesystem/inode_metadata.hpp"
 
 #include <cstddef>
 
@@ -10,8 +11,13 @@ namespace filesystem
   struct inode
   {
     inode() = default;
+    explicit inode(inode_kind kind);
     explicit inode(devices::device * device);
 
+    [[nodiscard]] auto metadata() const -> inode_metadata;
+
+    [[nodiscard]] auto is_directory() const -> bool;
+    [[nodiscard]] auto is_regular() const -> bool;
     [[nodiscard]] auto is_device() const -> bool;
     [[nodiscard]] auto is_block_device() const -> bool;
     [[nodiscard]] auto major_device() const -> size_t;
@@ -22,6 +28,7 @@ namespace filesystem
     auto write(void const * buffer, size_t offset, size_t size) -> size_t;
 
   private:
+    inode_kind m_kind{inode_kind::regular};
     devices::device * m_device{};
   };
 }  // namespace filesystem
diff --git a/kernel/filesystem/include/filesystem/inode_metadata.hpp b/kernel/filesystem/include/filesystem/inode_metadata.hpp
new file mode 100644
index 0000000..ed5a09d
--- /dev/null
+++ b/kernel/filesystem/include/filesystem/inode_metadata.hpp
@@ -0,0 +1,24 @@
+#ifndef TEACH_OS_KERNEL_FILESYSTEM_INODE_METADATA_HPP
+#define TEACH_OS_KERNEL_FILESYSTEM_INODE_METADATA_HPP
+
+#include <cstddef>
+#include <optional>
+
+namespace filesystem
+{
+  enum class inode_kind
+  {
+    regular,
+    directory,
+    device
+  };
+
+  struct inode_metadata
+  {
+    inode_kind kind{inode_kind::regular};
+    std::optional<size_t> major{};
+    std::optional<size_t> minor{};
+  };
+}  // namespace filesystem
+
+#endif  // TEACH_OS_KERNEL_FILESYSTEM_INODE_METADATA_HPP
+\ No newline at end of file
diff --git a/kernel/filesystem/src/ext2/ext2_filesystem.cpp b/kernel/filesystem/src/ext2/ext2_filesystem.cpp
index 97257a2..f092ddf 100644
--- a/kernel/filesystem/src/ext2/ext2_filesystem.cpp
+++ b/kernel/filesystem/src/ext2/ext2_filesystem.cpp
@@ -3,6 +3,8 @@
 #include "devices/device.hpp"
 #include "filesystem/inode.hpp"
 
+#include <string_view>
+
 namespace filesystem::ext2
 {
   auto ext2_filesystem::mount(devices::device * device) -> int
@@ -12,9 +14,17 @@ namespace filesystem::ext2
       return -1;  // TODO BA-FS26 panic or errorcode?
     }
 
-    m_root_inode = inode{};  // TODO BA-FS26 set properly during mount?
+    m_device = device;
+    // TODO BA-FS26 load proper root inode from ext2 metadata
+    m_root_inode = inode{inode_kind::directory};
 
     // TODO BA-FS26 implement
     return 0;
   }
-}  // namespace filesystem::ext2
-\ No newline at end of file
+
+  auto ext2_filesystem::lookup(inode const & /*parent*/, std::string_view /*name*/) -> inode *
+  {
+    // TODO BA-FS26 implement ext2 directory traversal and inode loading
+    return nullptr;
+  }
+}  // namespace filesystem::ext2
diff --git a/kernel/filesystem/src/filesystem.cpp b/kernel/filesystem/src/filesystem.cpp
index cdfe7f8..a06bccc 100644
--- a/kernel/filesystem/src/filesystem.cpp
+++ b/kernel/filesystem/src/filesystem.cpp
@@ -4,8 +4,13 @@
 
 namespace filesystem
 {
-  auto filesystem::root_inode() const -> inode const &
+  auto filesystem::root_inode() -> inode *
   {
-    return m_root_inode;
+    return &m_root_inode;
+  }
+
+  auto filesystem::root_inode() const -> inode const *
+  {
+    return &m_root_inode;
   }
 }  // namespace filesystem
 \ No newline at end of file
diff --git a/kernel/filesystem/src/inode.cpp b/kernel/filesystem/src/inode.cpp
index a1427e2..17aa52a 100644
--- a/kernel/filesystem/src/inode.cpp
+++ b/kernel/filesystem/src/inode.cpp
@@ -3,13 +3,19 @@
 #include "kapi/system.hpp"
 
 #include "devices/device.hpp"
+#include "filesystem/inode_metadata.hpp"
 
 #include <cstddef>
 
 namespace filesystem
 {
+  inode::inode(inode_kind kind)
+      : m_kind(kind)
+  {}
+
   inode::inode(devices::device * device)
-      : m_device(device)
+      : m_kind(inode_kind::device)
+      , m_device(device)
   {
     if (!m_device)
     {
@@ -17,9 +23,33 @@ namespace filesystem
     }
   }
 
+  auto inode::metadata() const -> inode_metadata
+  {
+    auto meta = inode_metadata{};
+    meta.kind = m_kind;
+
+    if (is_device())
+    {
+      meta.major = m_device->major();
+      meta.minor = m_device->minor();
+    }
+
+    return meta;
+  }
+
+  auto inode::is_directory() const -> bool
+  {
+    return m_kind == inode_kind::directory;
+  }
+
+  auto inode::is_regular() const -> bool
+  {
+    return m_kind == inode_kind::regular;
+  }
+
   auto inode::is_device() const -> bool
   {
-    return m_device != nullptr;
+    return m_kind == inode_kind::device;
   }
 
   auto inode::is_block_device() const -> bool