From ba63fbfc2bb43a6f0f05b6b49fd51fd6c89a0861 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Sat, 21 Mar 2026 00:28:17 +0100
Subject: refactor file and inode architecture again

---
 kernel/CMakeLists.txt                              |  1 +
 kernel/include/kernel/filesystem/device_file.hpp   |  6 ++++--
 kernel/include/kernel/filesystem/device_inode.hpp  |  7 ++++--
 kernel/include/kernel/filesystem/disk_file.hpp     | 19 ----------------
 .../include/kernel/filesystem/ext2/ext2_file.hpp   |  8 +++----
 .../include/kernel/filesystem/ext2/ext2_inode.hpp  |  9 ++++----
 kernel/include/kernel/filesystem/file.hpp          |  8 +++++++
 kernel/include/kernel/filesystem/inode.hpp         |  8 +++----
 kernel/include/kernel/filesystem/inode_file.hpp    |  9 ++++----
 kernel/src/filesystem/device_file.cpp              | 25 +++++++++++++++-------
 kernel/src/filesystem/device_inode.cpp             | 14 ++++++++++--
 kernel/src/filesystem/ext2/ext2_inode.cpp          | 15 ++++++++-----
 kernel/src/filesystem/file.cpp                     | 20 +++++++++++++++++
 kernel/src/filesystem/inode_file.cpp               | 21 ++++++++++--------
 kernel/src/filesystem/vfs.cpp                      |  5 +++--
 kernel/src/main.cpp                                |  5 ++++-
 16 files changed, 112 insertions(+), 68 deletions(-)
 delete mode 100644 kernel/include/kernel/filesystem/disk_file.hpp
 create mode 100644 kernel/src/filesystem/file.cpp

diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index e0b40be..ec0d4e2 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -27,6 +27,7 @@ add_executable("kernel"
     "src/filesystem/custody.cpp"
     "src/filesystem/device_file.cpp"
     "src/filesystem/device_inode.cpp"
+    "src/filesystem/file.cpp"
     "src/filesystem/file_descriptor_table.cpp"
     "src/filesystem/filesystem.cpp"
     "src/filesystem/inode_file.cpp"
diff --git a/kernel/include/kernel/filesystem/device_file.hpp b/kernel/include/kernel/filesystem/device_file.hpp
index ff803f8..22ddb49 100644
--- a/kernel/include/kernel/filesystem/device_file.hpp
+++ b/kernel/include/kernel/filesystem/device_file.hpp
@@ -11,9 +11,11 @@
 
 namespace filesystem
 {
+  struct inode;
+
   struct device_file : file
   {
-    explicit device_file(kstd::shared_ptr<devices::device> const & device);
+    explicit device_file(kstd::shared_ptr<inode> const & inode);
 
     auto read(void * buffer, size_t offset, size_t size) const -> size_t override;
     auto write(void const * buffer, size_t offset, size_t size) -> size_t override;
@@ -23,7 +25,7 @@ namespace filesystem
                               std::byte * scratch, void * buffer);
     auto process_blocks(size_t offset, size_t size, void * buffer, block_op op) const -> size_t;
 
-    kstd::shared_ptr<devices::device> m_device;
+    [[nodiscard]] auto device() const -> kstd::shared_ptr<devices::device> const &;
   };
 }  // namespace filesystem
 
diff --git a/kernel/include/kernel/filesystem/device_inode.hpp b/kernel/include/kernel/filesystem/device_inode.hpp
index c38c75b..af2a51b 100644
--- a/kernel/include/kernel/filesystem/device_inode.hpp
+++ b/kernel/include/kernel/filesystem/device_inode.hpp
@@ -2,18 +2,21 @@
 #define TEACH_OS_KERNEL_FILESYSTEM_DEVICE_INODE_HPP
 
 #include "kernel/devices/device.hpp"
-#include "kernel/filesystem/file.hpp"
 #include "kernel/filesystem/inode.hpp"
 
 #include <kstd/memory>
 
 namespace filesystem
 {
+  struct file;
+
   struct device_inode : inode
   {
     explicit device_inode(kstd::shared_ptr<devices::device> const & device);
 
-    [[nodiscard]] auto open_file() const -> kstd::shared_ptr<file> override;
+    [[nodiscard]] auto open_file(kstd::shared_ptr<inode> const & self) const -> kstd::shared_ptr<file> override;
+
+    [[nodiscard]] auto device() const -> kstd::shared_ptr<devices::device> const &;
 
   private:
     kstd::shared_ptr<devices::device> m_device{};
diff --git a/kernel/include/kernel/filesystem/disk_file.hpp b/kernel/include/kernel/filesystem/disk_file.hpp
deleted file mode 100644
index c6a7655..0000000
--- a/kernel/include/kernel/filesystem/disk_file.hpp
+++ /dev/null
@@ -1,19 +0,0 @@
-#ifndef TEACH_OS_KERNEL_FILESYSTEM_DISK_FILE_HPP
-#define TEACH_OS_KERNEL_FILESYSTEM_DISK_FILE_HPP
-
-#include <kstd/memory>
-
-#include <cstddef>
-
-namespace filesystem
-{
-  struct disk_file
-  {
-    virtual ~disk_file() = default;
-
-    virtual auto read(void * buffer, size_t offset, size_t size) const -> size_t = 0;
-    virtual auto write(void const * buffer, size_t offset, size_t size) -> size_t = 0;
-  };
-}  // namespace filesystem
-
-#endif
\ No newline at end of file
diff --git a/kernel/include/kernel/filesystem/ext2/ext2_file.hpp b/kernel/include/kernel/filesystem/ext2/ext2_file.hpp
index 371507d..e5357e3 100644
--- a/kernel/include/kernel/filesystem/ext2/ext2_file.hpp
+++ b/kernel/include/kernel/filesystem/ext2/ext2_file.hpp
@@ -1,16 +1,14 @@
 #ifndef TEACH_OS_KERNEL_FILESYSTEM_EXT2_FILE_HPP
 #define TEACH_OS_KERNEL_FILESYSTEM_EXT2_FILE_HPP
 
-#include "kernel/filesystem/disk_file.hpp"
-
 #include <cstddef>
 
 namespace filesystem::ext2
 {
-  struct ext2_file : disk_file
+  struct ext2_file
   {
-    auto read(void * buffer, size_t offset, size_t size) const -> size_t override;
-    auto write(void const * buffer, size_t offset, size_t size) -> size_t override;
+    auto read(void * buffer, size_t offset, size_t size) const -> size_t;
+    auto write(void const * buffer, size_t offset, size_t size) -> size_t;
   };
 }  // namespace filesystem::ext2
 
diff --git a/kernel/include/kernel/filesystem/ext2/ext2_inode.hpp b/kernel/include/kernel/filesystem/ext2/ext2_inode.hpp
index 7b5ff3f..b57d267 100644
--- a/kernel/include/kernel/filesystem/ext2/ext2_inode.hpp
+++ b/kernel/include/kernel/filesystem/ext2/ext2_inode.hpp
@@ -1,7 +1,7 @@
 #ifndef TEACH_OS_KERNEL_FILESYSTEM_EXT2_INODE_HPP
 #define TEACH_OS_KERNEL_FILESYSTEM_EXT2_INODE_HPP
 
-#include "kernel/filesystem/disk_file.hpp"
+#include "kernel/filesystem/ext2/ext2_file.hpp"
 #include "kernel/filesystem/file.hpp"
 #include "kernel/filesystem/inode.hpp"
 
@@ -11,12 +11,13 @@ namespace filesystem::ext2
 {
   struct ext2_inode : inode
   {
-    explicit ext2_inode(kstd::shared_ptr<disk_file> const & disk_file);
+    explicit ext2_inode();
 
-    [[nodiscard]] auto open_file() const -> kstd::shared_ptr<file> override;
+    [[nodiscard]] auto open_file(kstd::shared_ptr<inode> const & self) const
+        -> kstd::shared_ptr<filesystem::file> override;
 
   private:
-    kstd::shared_ptr<disk_file> m_disk_file{};
+    kstd::shared_ptr<ext2_file> m_file{};
   };
 }  // namespace filesystem::ext2
 
diff --git a/kernel/include/kernel/filesystem/file.hpp b/kernel/include/kernel/filesystem/file.hpp
index 5a41fab..522f078 100644
--- a/kernel/include/kernel/filesystem/file.hpp
+++ b/kernel/include/kernel/filesystem/file.hpp
@@ -1,16 +1,24 @@
 #ifndef TEACH_OS_KERNEL_FILESYSTEM_FILE_HPP
 #define TEACH_OS_KERNEL_FILESYSTEM_FILE_HPP
 
+#include <kstd/memory>
+
 #include <cstddef>
 
 namespace filesystem
 {
+  struct inode; 
+
   struct file
   {
+    explicit file(kstd::shared_ptr<inode> const & inode);
     virtual ~file() = default;
 
     virtual auto read(void * buffer, size_t offset, size_t size) const -> size_t = 0;
     virtual auto write(void const * buffer, size_t offset, size_t size) -> size_t = 0;
+
+  protected:
+    kstd::shared_ptr<inode> m_inode;
   };
 }  // namespace filesystem
 
diff --git a/kernel/include/kernel/filesystem/inode.hpp b/kernel/include/kernel/filesystem/inode.hpp
index 79cbcf9..8c9f75e 100644
--- a/kernel/include/kernel/filesystem/inode.hpp
+++ b/kernel/include/kernel/filesystem/inode.hpp
@@ -1,12 +1,12 @@
 #ifndef TEACH_OS_KERNEL_FILESYSTEM_INODE_HPP
 #define TEACH_OS_KERNEL_FILESYSTEM_INODE_HPP
 
-#include "kernel/filesystem/file.hpp"
-
 #include <kstd/memory>
 
 namespace filesystem
 {
+  struct file;
+
   struct inode
   {
     enum class inode_kind
@@ -20,12 +20,12 @@ namespace filesystem
 
     virtual ~inode() = default;
 
+    [[nodiscard]] virtual auto open_file(kstd::shared_ptr<inode> const & self) const -> kstd::shared_ptr<file> = 0;
+
     [[nodiscard]] auto is_directory() const -> bool;
     [[nodiscard]] auto is_regular() const -> bool;
     [[nodiscard]] auto is_device() const -> bool;
 
-    [[nodiscard]] virtual auto open_file() const -> kstd::shared_ptr<file> = 0;
-
   private:
     inode_kind m_kind{inode_kind::regular};
   };
diff --git a/kernel/include/kernel/filesystem/inode_file.hpp b/kernel/include/kernel/filesystem/inode_file.hpp
index 3e2b954..f87b77c 100644
--- a/kernel/include/kernel/filesystem/inode_file.hpp
+++ b/kernel/include/kernel/filesystem/inode_file.hpp
@@ -1,8 +1,8 @@
 #ifndef TEACH_OS_KERNEL_FILESYSTEM_INODE_FILE_HPP
 #define TEACH_OS_KERNEL_FILESYSTEM_INODE_FILE_HPP
 
-#include "kernel/filesystem/disk_file.hpp"
 #include "kernel/filesystem/file.hpp"
+#include "kernel/filesystem/inode.hpp"
 
 #include <kstd/memory>
 
@@ -10,15 +10,14 @@
 
 namespace filesystem
 {
+  struct inode;
+
   struct inode_file : file
   {
-    explicit inode_file(kstd::shared_ptr<disk_file> const & disk_file);
+    explicit inode_file(kstd::shared_ptr<inode> const & inode);
 
     auto read(void * buffer, size_t offset, size_t size) const -> size_t override;
     auto write(void const * buffer, size_t offset, size_t size) -> size_t override;
-
-  private:
-    kstd::shared_ptr<disk_file> m_disk_file;
   };
 }  // namespace filesystem
 
diff --git a/kernel/src/filesystem/device_file.cpp b/kernel/src/filesystem/device_file.cpp
index 48ed20d..26c7511 100644
--- a/kernel/src/filesystem/device_file.cpp
+++ b/kernel/src/filesystem/device_file.cpp
@@ -4,6 +4,9 @@
 
 #include "kernel/devices/block_device.hpp"
 #include "kernel/devices/device.hpp"
+#include "kernel/filesystem/device_inode.hpp"
+#include "kernel/filesystem/file.hpp"
+#include "kernel/filesystem/inode.hpp"
 
 #include <kstd/cstring>
 #include <kstd/memory>
@@ -14,18 +17,18 @@
 
 namespace filesystem
 {
-  device_file::device_file(kstd::shared_ptr<devices::device> const & device)
-      : m_device(device)
+  device_file::device_file(kstd::shared_ptr<inode> const & inode)
+      : file(inode)
   {
-    if (!m_device)
+    if (!m_inode->is_device())
     {
-      kapi::system::panic("[FILESYSTEM] device_file constructed with null device.");
+      kapi::system::panic("[FILESYSTEM] device_file constructed with non-device inode.");
     }
   }
 
   auto device_file::read(void * buffer, size_t offset, size_t size) const -> size_t
   {
-    if (m_device->is_block_device())
+    if (device()->is_block_device())
     {
       return process_blocks(offset, size, buffer,
                             [](size_t idx, size_t off, size_t len, size_t done, devices::block_device * device,
@@ -50,7 +53,7 @@ namespace filesystem
 
   auto device_file::write(void const * buffer, size_t offset, size_t size) -> size_t
   {
-    if (m_device->is_block_device())
+    if (device()->is_block_device())
     {
       return process_blocks(offset, size, const_cast<void *>(buffer),
                             [](size_t idx, size_t off, size_t len, size_t done, devices::block_device * device,
@@ -78,7 +81,7 @@ namespace filesystem
   {
     if (buffer == nullptr)
     {
-      kapi::system::panic("[FILESYSTEM] device_file::write called with null buffer.");
+      kapi::system::panic("[FILESYSTEM] device_file::process_blocks called with null buffer.");
     }
 
     if (size == 0)
@@ -86,7 +89,7 @@ namespace filesystem
       return 0;
     }
 
-    auto * block_dev = static_cast<devices::block_device *>(m_device.get());
+    auto * block_dev = static_cast<devices::block_device *>(device().get());
     if (block_dev == nullptr)
     {
       kapi::system::panic("[FILESYSTEM] device_file: expected block_device.");
@@ -116,4 +119,10 @@ namespace filesystem
 
     return processed;
   }
+
+  auto device_file::device() const -> kstd::shared_ptr<devices::device> const &
+  {
+    auto inode = static_cast<device_inode *>(m_inode.get());
+    return inode->device();
+  }
 }  // namespace filesystem
diff --git a/kernel/src/filesystem/device_inode.cpp b/kernel/src/filesystem/device_inode.cpp
index 592637d..65dd9a3 100644
--- a/kernel/src/filesystem/device_inode.cpp
+++ b/kernel/src/filesystem/device_inode.cpp
@@ -21,8 +21,18 @@ namespace filesystem
     }
   }
 
-  auto device_inode::open_file() const -> kstd::shared_ptr<file>
+  auto device_inode::open_file(kstd::shared_ptr<inode> const & self) const -> kstd::shared_ptr<file>
   {
-    return kstd::make_shared<device_file>(m_device);
+    if (!self)
+    {
+      kapi::system::panic("[FILESYSTEM] device_inode::open_file called with null inode.");
+    }
+
+    return kstd::make_shared<device_file>(self);
+  }
+
+  auto device_inode::device() const -> kstd::shared_ptr<devices::device> const &
+  {
+    return m_device;
   }
 }  // namespace filesystem
\ No newline at end of file
diff --git a/kernel/src/filesystem/ext2/ext2_inode.cpp b/kernel/src/filesystem/ext2/ext2_inode.cpp
index 8131f43..0a1994b 100644
--- a/kernel/src/filesystem/ext2/ext2_inode.cpp
+++ b/kernel/src/filesystem/ext2/ext2_inode.cpp
@@ -1,6 +1,7 @@
 #include "kernel/filesystem/ext2/ext2_inode.hpp"
 
-#include "kernel/filesystem/disk_file.hpp"
+#include "kapi/system.hpp"
+
 #include "kernel/filesystem/file.hpp"
 #include "kernel/filesystem/inode.hpp"
 #include "kernel/filesystem/inode_file.hpp"
@@ -9,13 +10,17 @@
 
 namespace filesystem::ext2
 {
-  ext2_inode::ext2_inode(kstd::shared_ptr<disk_file> const & disk_file)
+  ext2_inode::ext2_inode()
       : inode(inode_kind::regular)
-      , m_disk_file(disk_file)
   {}
 
-  auto ext2_inode::open_file() const -> kstd::shared_ptr<file>
+  auto ext2_inode::open_file(kstd::shared_ptr<inode> const & self) const -> kstd::shared_ptr<filesystem::file>
   {
-    return kstd::make_shared<inode_file>(m_disk_file);
+    if (!self)
+    {
+      kapi::system::panic("[FILESYSTEM] ext2_inode::open_file called with null inode.");
+    }
+
+    return kstd::make_shared<inode_file>(self);
   }
 }  // namespace filesystem::ext2
\ No newline at end of file
diff --git a/kernel/src/filesystem/file.cpp b/kernel/src/filesystem/file.cpp
new file mode 100644
index 0000000..a147863
--- /dev/null
+++ b/kernel/src/filesystem/file.cpp
@@ -0,0 +1,20 @@
+#include "kernel/filesystem/file.hpp"
+
+#include "kapi/system.hpp"
+
+#include "kernel/filesystem/inode.hpp"
+
+#include <kstd/memory>
+
+namespace filesystem
+{
+
+  file::file(kstd::shared_ptr<inode> const & inode)
+      : m_inode(inode)
+  {
+    if (!m_inode)
+    {
+      kapi::system::panic("[FILESYSTEM] file constructed with null inode.");
+    }
+  }
+}  // namespace filesystem
\ No newline at end of file
diff --git a/kernel/src/filesystem/inode_file.cpp b/kernel/src/filesystem/inode_file.cpp
index 9c351da..8b2fcba 100644
--- a/kernel/src/filesystem/inode_file.cpp
+++ b/kernel/src/filesystem/inode_file.cpp
@@ -2,7 +2,8 @@
 
 #include "kapi/system.hpp"
 
-#include "kernel/filesystem/disk_file.hpp"
+#include "kernel/filesystem/file.hpp"
+#include "kernel/filesystem/inode.hpp"
 
 #include <kstd/memory>
 
@@ -10,22 +11,24 @@
 
 namespace filesystem
 {
-  inode_file::inode_file(kstd::shared_ptr<disk_file> const & disk_file)
-      : m_disk_file(disk_file)
+  inode_file::inode_file(kstd::shared_ptr<inode> const & inode)
+      : file(inode)
   {
-    if (!m_disk_file)
+    if (m_inode->is_device())
     {
-      kapi::system::panic("[FILESYSTEM] inode_file constructed with null disk_file.");
+      kapi::system::panic("[FILESYSTEM] inode_file constructed with device inode.");
     }
   }
 
-  auto inode_file::read(void * buffer, size_t offset, size_t size) const -> size_t
+  auto inode_file::read(void * /*buffer*/, size_t /*offset*/, size_t /*size*/) const -> size_t
   {
-    return m_disk_file->read(buffer, offset, size);
+    // TODO BA-FS26
+    return 0;
   }
 
-  auto inode_file::write(void const * buffer, size_t offset, size_t size) -> size_t
+  auto inode_file::write(void const * /*buffer*/, size_t /*offset*/, size_t /*size*/) -> size_t
   {
-    return m_disk_file->write(buffer, offset, size);
+    // TODO BA-FS26
+    return 0;
   }
 }  // namespace filesystem
\ No newline at end of file
diff --git a/kernel/src/filesystem/vfs.cpp b/kernel/src/filesystem/vfs.cpp
index ee5fd9b..5330b82 100644
--- a/kernel/src/filesystem/vfs.cpp
+++ b/kernel/src/filesystem/vfs.cpp
@@ -34,6 +34,7 @@ namespace filesystem
     active_vfs.emplace(vfs{});
 
     auto storage_mgmt = devices::storage::storage_management::get();
+    // TODO BA-FS26 fix mounting boot_device
     if (auto boot_device = storage_mgmt.determine_boot_device())
     {
       active_vfs->m_root_fs = kstd::make_shared<ext2::ext2_filesystem>();
@@ -69,9 +70,9 @@ namespace filesystem
     {
       auto node = custody->get_inode();
 
-      if (auto current_inode_file = node->open_file())
+      if (auto opened_file = node->open_file(node))
       {
-        return kstd::make_shared<open_file_description>(current_inode_file);
+        return kstd::make_shared<open_file_description>(opened_file);
       }
 
       kapi::system::panic("[FILESYSTEM] inode::open_file returned null file.");
diff --git a/kernel/src/main.cpp b/kernel/src/main.cpp
index 31133a5..8d7308b 100644
--- a/kernel/src/main.cpp
+++ b/kernel/src/main.cpp
@@ -5,6 +5,7 @@
 
 #include "kernel/devices/storage/storage_management.hpp"
 #include "kernel/filesystem/device_file.hpp"
+#include "kernel/filesystem/device_inode.hpp"
 #include "kernel/filesystem/file_descriptor_table.hpp"
 #include "kernel/filesystem/open_file_description.hpp"
 #include "kernel/filesystem/vfs.hpp"
@@ -25,7 +26,9 @@ auto test_file_description_manually() -> void
   auto storage_mgmt = devices::storage::storage_management::get();
   auto device = storage_mgmt.device_by_major_minor(1, 0);
 
-  auto dev_file = kstd::make_shared<filesystem::device_file>(device);
+  auto dev_node = kstd::make_shared<filesystem::device_inode>(device);
+
+  auto dev_file = kstd::make_shared<filesystem::device_file>(dev_node);
   auto ofd = kstd::make_shared<filesystem::open_file_description>(dev_file);
   auto fd_index = fd_table.add_file(ofd);
 
-- 
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