From 72b40ecf33fb0ef2d4232b80560642296c79399c Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Thu, 2 Apr 2026 09:49:17 +0200
Subject: automatically detect the mounted file system type by trial-and-error

---
 kernel/include/kernel/filesystem/filesystem.hpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/filesystem.hpp b/kernel/include/kernel/filesystem/filesystem.hpp
index 1d86178..05f96dc 100644
--- a/kernel/include/kernel/filesystem/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/filesystem.hpp
@@ -2,6 +2,7 @@
 #define TEACH_OS_KERNEL_FILESYSTEM_FILESYSTEM_HPP
 
 #include "kapi/devices/device.hpp"
+
 #include "kernel/filesystem/inode.hpp"
 
 #include <kstd/memory>
@@ -15,7 +16,7 @@ namespace kernel::filesystem
   {
     virtual ~filesystem() = default;
 
-    virtual auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int;
+    auto static mount(kstd::shared_ptr<kapi::devices::device> const & device) -> kstd::shared_ptr<filesystem>;
     virtual auto lookup(kstd::shared_ptr<inode> const & parent, std::string_view name) -> kstd::shared_ptr<inode> = 0;
 
     [[nodiscard]] auto root_inode() const -> kstd::shared_ptr<inode> const &;
-- 
cgit v1.2.3


From 93bca4c2a7c1852fc89df6965c835a7dbbdd6512 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Thu, 2 Apr 2026 09:50:14 +0200
Subject: read ext2 superblock and check the magic number

---
 kernel/include/kernel/filesystem/ext2/filesystem.hpp | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index 078da31..176d83c 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -2,20 +2,29 @@
 #define TEACH_OS_KERNEL_FILESYSTEM_EXT2_FILESYSTEM_HPP
 
 #include "kapi/devices/device.hpp"
+
+#include "kernel/filesystem/ext2/superblock.hpp"
 #include "kernel/filesystem/filesystem.hpp"
 #include "kernel/filesystem/inode.hpp"
 
 #include <kstd/memory>
 
+#include <cstddef>
 #include <string_view>
 
 namespace kernel::filesystem::ext2
 {
   struct filesystem : kernel::filesystem::filesystem
   {
-    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override;
+    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int;
     auto lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name)
         -> kstd::shared_ptr<kernel::filesystem::inode> override;
+
+  private:
+    auto get_block_size() -> size_t;
+    auto get_inode_size() -> size_t;
+
+    superblock m_superblock;
   };
 }  // namespace kernel::filesystem::ext2
 
-- 
cgit v1.2.3


From 1dcf253fdf8169a3b2b71bfac68f2f25951af1a8 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Thu, 2 Apr 2026 10:04:04 +0200
Subject: fix build, refactoring

---
 kernel/include/kernel/filesystem/devfs/filesystem.hpp  | 1 +
 kernel/include/kernel/filesystem/ext2/filesystem.hpp   | 2 +-
 kernel/include/kernel/filesystem/filesystem.hpp        | 4 +++-
 kernel/include/kernel/filesystem/rootfs/filesystem.hpp | 1 +
 4 files changed, 6 insertions(+), 2 deletions(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/devfs/filesystem.hpp b/kernel/include/kernel/filesystem/devfs/filesystem.hpp
index 29ae388..3edeabb 100644
--- a/kernel/include/kernel/filesystem/devfs/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/devfs/filesystem.hpp
@@ -2,6 +2,7 @@
 #define TEACH_OS_KERNEL_FILESYSTEM_DEVFS_FILESYSTEM_HPP
 
 #include "kapi/devices/device.hpp"
+
 #include "kernel/filesystem/filesystem.hpp"
 #include "kernel/filesystem/inode.hpp"
 
diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index 176d83c..f6cd17f 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -16,7 +16,7 @@ namespace kernel::filesystem::ext2
 {
   struct filesystem : kernel::filesystem::filesystem
   {
-    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int;
+    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override;
     auto lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name)
         -> kstd::shared_ptr<kernel::filesystem::inode> override;
 
diff --git a/kernel/include/kernel/filesystem/filesystem.hpp b/kernel/include/kernel/filesystem/filesystem.hpp
index 05f96dc..1c45377 100644
--- a/kernel/include/kernel/filesystem/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/filesystem.hpp
@@ -16,7 +16,9 @@ namespace kernel::filesystem
   {
     virtual ~filesystem() = default;
 
-    auto static mount(kstd::shared_ptr<kapi::devices::device> const & device) -> kstd::shared_ptr<filesystem>;
+    auto static probe_and_mount(kstd::shared_ptr<kapi::devices::device> const & device) -> kstd::shared_ptr<filesystem>;
+
+    virtual auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int;
     virtual auto lookup(kstd::shared_ptr<inode> const & parent, std::string_view name) -> kstd::shared_ptr<inode> = 0;
 
     [[nodiscard]] auto root_inode() const -> kstd::shared_ptr<inode> const &;
diff --git a/kernel/include/kernel/filesystem/rootfs/filesystem.hpp b/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
index 5632d86..7931d87 100644
--- a/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
@@ -2,6 +2,7 @@
 #define TEACH_OS_KERNEL_FILESYSTEM_ROOTFS_FILESYSTEM_HPP
 
 #include "kapi/devices/device.hpp"
+
 #include "kernel/filesystem/filesystem.hpp"
 #include "kernel/filesystem/inode.hpp"
 
-- 
cgit v1.2.3


From 16b854e991bb791694268d09eb696c719cdff42f Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Thu, 2 Apr 2026 11:09:13 +0200
Subject: read block_group_descriptors

---
 kernel/include/kernel/filesystem/ext2/filesystem.hpp | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index f6cd17f..59b9cba 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -3,11 +3,13 @@
 
 #include "kapi/devices/device.hpp"
 
+#include "kernel/filesystem/ext2/block_group_descriptor.hpp"
 #include "kernel/filesystem/ext2/superblock.hpp"
 #include "kernel/filesystem/filesystem.hpp"
 #include "kernel/filesystem/inode.hpp"
 
 #include <kstd/memory>
+#include <kstd/vector>
 
 #include <cstddef>
 #include <string_view>
@@ -25,6 +27,7 @@ namespace kernel::filesystem::ext2
     auto get_inode_size() -> size_t;
 
     superblock m_superblock;
+    kstd::vector<block_group_descriptor> m_block_group_descriptors;
   };
 }  // namespace kernel::filesystem::ext2
 
-- 
cgit v1.2.3


From 91db623189133cb14693ae60ee54ac293cec3b54 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Thu, 2 Apr 2026 11:33:14 +0200
Subject: remove todos

---
 kernel/include/kernel/filesystem/ext2/superblock.hpp | 5 -----
 1 file changed, 5 deletions(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/superblock.hpp b/kernel/include/kernel/filesystem/ext2/superblock.hpp
index 8600b4c..e7e15f2 100644
--- a/kernel/include/kernel/filesystem/ext2/superblock.hpp
+++ b/kernel/include/kernel/filesystem/ext2/superblock.hpp
@@ -41,11 +41,8 @@ namespace kernel::filesystem::ext2
     uint32_t feature_compat;
     uint32_t feature_incompat;
     uint32_t feature_ro_compat;
-    // uint8_t uuid[16];  // TODO BA-FS26 really correct?
     std::array<uint8_t, 16> uuid;
-    // uint8_t volume_name[16]; // TODO BA-FS26 really correct?
     std::array<uint8_t, 16> volume_name;
-    // uint8_t last_mounted[64]; // TODO BA-FS26 really correct?
     std::array<uint8_t, 64> last_mounted;
     uint32_t algorithm_usage_bitmap;
 
@@ -55,14 +52,12 @@ namespace kernel::filesystem::ext2
     uint16_t padding1;
 
     // Journaling Support
-    // uint8_t journal_uuid[16]; // TODO BA-FS26 really correct?
     std::array<uint8_t, 16> journal_uuid;
     uint32_t journal_inum;
     uint32_t journal_dev;
     uint32_t last_orphan;
 
     // Directory Indexing Support
-    // uint32_t hash_seed[4]; // TODO BA-FS26 really correct?
     std::array<uint32_t, 4> hash_seed;
     uint8_t def_hash_version;
     std::array<uint8_t, 3> padding2;
-- 
cgit v1.2.3


From baf63039d5430c0b3b1e6235b561c12f60e97f49 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Thu, 2 Apr 2026 15:03:06 +0200
Subject: implement read_inode

---
 .../kernel/filesystem/ext2/block_group_descriptor.hpp |  2 +-
 kernel/include/kernel/filesystem/ext2/filesystem.hpp  |  4 ++++
 kernel/include/kernel/filesystem/ext2/inode.hpp       | 19 +++++++++++--------
 .../kernel/filesystem/ext2/linked_directory_entry.hpp |  2 +-
 kernel/include/kernel/filesystem/ext2/superblock.hpp  |  2 +-
 5 files changed, 18 insertions(+), 11 deletions(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/block_group_descriptor.hpp b/kernel/include/kernel/filesystem/ext2/block_group_descriptor.hpp
index a23c045..2ff91d9 100644
--- a/kernel/include/kernel/filesystem/ext2/block_group_descriptor.hpp
+++ b/kernel/include/kernel/filesystem/ext2/block_group_descriptor.hpp
@@ -6,7 +6,7 @@
 
 namespace kernel::filesystem::ext2
 {
-  struct block_group_descriptor
+  struct [[gnu::packed]] block_group_descriptor
   {
     uint32_t block_bitmap;
     uint32_t inode_bitmap;
diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index 59b9cba..ccee172 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -4,6 +4,7 @@
 #include "kapi/devices/device.hpp"
 
 #include "kernel/filesystem/ext2/block_group_descriptor.hpp"
+#include "kernel/filesystem/ext2/inode.hpp"
 #include "kernel/filesystem/ext2/superblock.hpp"
 #include "kernel/filesystem/filesystem.hpp"
 #include "kernel/filesystem/inode.hpp"
@@ -12,6 +13,7 @@
 #include <kstd/vector>
 
 #include <cstddef>
+#include <cstdint>
 #include <string_view>
 
 namespace kernel::filesystem::ext2
@@ -23,6 +25,8 @@ namespace kernel::filesystem::ext2
         -> kstd::shared_ptr<kernel::filesystem::inode> override;
 
   private:
+    auto read_inode(uint32_t inode_number) -> kstd::shared_ptr<kernel::filesystem::ext2::inode>;
+
     auto get_block_size() -> size_t;
     auto get_inode_size() -> size_t;
 
diff --git a/kernel/include/kernel/filesystem/ext2/inode.hpp b/kernel/include/kernel/filesystem/ext2/inode.hpp
index 2c27c17..4284e6f 100644
--- a/kernel/include/kernel/filesystem/ext2/inode.hpp
+++ b/kernel/include/kernel/filesystem/ext2/inode.hpp
@@ -11,13 +11,8 @@
 
 namespace kernel::filesystem::ext2
 {
-  struct inode : kernel::filesystem::inode
+  struct [[gnu::packed]] inode_data
   {
-    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;
-
     uint16_t mode;
     uint16_t uid;
     uint32_t size;
@@ -30,15 +25,23 @@ namespace kernel::filesystem::ext2
     uint32_t blocks;
     uint32_t flags;
     uint32_t osd1;
-    // uint32_t block[15]; // TODO BA-FS26 really correct?
     std::array<uint32_t, 15> block;  // NOLINT(readability-magic-numbers)
     uint32_t generation;
     uint32_t file_acl;
     uint32_t dir_acl;
     uint32_t faddr;
-    // uint8_t osd2[12]; // TODO BA-FS26 really correct?
     std::array<uint8_t, 12> osd2;  // NOLINT(readability-magic-numbers)
   };
+
+  struct inode : kernel::filesystem::inode
+  {
+    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;
+
+    inode_data m_data{};
+  };
 }  // namespace kernel::filesystem::ext2
 
 #endif
\ No newline at end of file
diff --git a/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp b/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
index 8dd42a1..f44255a 100644
--- a/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
+++ b/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
@@ -6,7 +6,7 @@
 
 namespace kernel::filesystem::ext2
 {
-  struct linked_directory_entry
+  struct [[gnu::packed]] linked_directory_entry
   {
     uint32_t inode;
     uint16_t rec_len;
diff --git a/kernel/include/kernel/filesystem/ext2/superblock.hpp b/kernel/include/kernel/filesystem/ext2/superblock.hpp
index e7e15f2..8e57ae7 100644
--- a/kernel/include/kernel/filesystem/ext2/superblock.hpp
+++ b/kernel/include/kernel/filesystem/ext2/superblock.hpp
@@ -6,7 +6,7 @@
 
 namespace kernel::filesystem::ext2
 {
-  struct superblock
+  struct [[gnu::packed]] superblock
   {
     uint32_t inodes_count;
     uint32_t blocks_count;
-- 
cgit v1.2.3


From 794de4a7f8dbea164d857ae9e4525536f338518d Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Thu, 2 Apr 2026 16:06:40 +0200
Subject: temporary implementation of inode kind

---
 kernel/include/kernel/filesystem/inode.hpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/inode.hpp b/kernel/include/kernel/filesystem/inode.hpp
index d97b5ab..59207df 100644
--- a/kernel/include/kernel/filesystem/inode.hpp
+++ b/kernel/include/kernel/filesystem/inode.hpp
@@ -25,7 +25,8 @@ namespace kernel::filesystem
     [[nodiscard]] auto is_regular() const -> bool;
     [[nodiscard]] auto is_device() const -> bool;
 
-  private:
+    // TODO BA-FS26 improve inode_kind really needed?
+  public:
     inode_kind m_kind{inode_kind::regular};
   };
 }  // namespace kernel::filesystem
-- 
cgit v1.2.3


From 15ea1551e54c36ebac26f21dc156636e326298c6 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Fri, 3 Apr 2026 14:29:32 +0200
Subject: fix linked_directory_entry struct

---
 kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp b/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
index f44255a..76eb6f5 100644
--- a/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
+++ b/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
@@ -12,8 +12,7 @@ namespace kernel::filesystem::ext2
     uint16_t rec_len;
     uint8_t name_len;
     uint8_t file_type;
-    uint8_t pad;
-    std::array<uint8_t, 255> name;  // NOLINT(readability-magic-numbers)
+    std::array<char, 255> name;  // NOLINT(readability-magic-numbers)
   };
 }  // namespace kernel::filesystem::ext2
 
-- 
cgit v1.2.3


From 7e6137b2725d5cf2b16f55678dcfb99091f03fe9 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Fri, 3 Apr 2026 14:30:20 +0200
Subject: implement map_inode_block_index_to_global_block_number and lookup

---
 kernel/include/kernel/filesystem/ext2/filesystem.hpp | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index ccee172..dea059f 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -26,9 +26,11 @@ namespace kernel::filesystem::ext2
 
   private:
     auto read_inode(uint32_t inode_number) -> kstd::shared_ptr<kernel::filesystem::ext2::inode>;
+    auto map_inode_block_index_to_global_block_number(uint32_t inode_block_index, inode_data data) -> uint32_t;
 
     auto get_block_size() -> size_t;
     auto get_inode_size() -> size_t;
+    auto get_inode_block_count(inode_data const & data) -> uint32_t;
 
     superblock m_superblock;
     kstd::vector<block_group_descriptor> m_block_group_descriptors;
-- 
cgit v1.2.3


From fe8706422605e466427ae2727ddb98ce5cd984f6 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Fri, 3 Apr 2026 15:38:16 +0200
Subject: refactoring map_inode_block_index_to_global_block_number

---
 kernel/include/kernel/filesystem/ext2/filesystem.hpp | 1 +
 1 file changed, 1 insertion(+)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index dea059f..9761903 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -27,6 +27,7 @@ namespace kernel::filesystem::ext2
   private:
     auto read_inode(uint32_t inode_number) -> kstd::shared_ptr<kernel::filesystem::ext2::inode>;
     auto map_inode_block_index_to_global_block_number(uint32_t inode_block_index, inode_data data) -> uint32_t;
+    auto read_block_number_at_index(uint32_t block_number, uint32_t index) -> uint32_t;
 
     auto get_block_size() -> size_t;
     auto get_inode_size() -> size_t;
-- 
cgit v1.2.3


From 725116d22e850c502e6cb8d42b100da1080dfec0 Mon Sep 17 00:00:00 2001
From: Marcel Braun <marcel.braun@ost.ch>
Date: Mon, 6 Apr 2026 10:35:45 +0200
Subject: Add file system pointer to ext2 inode

---
 kernel/include/kernel/filesystem/ext2/inode.hpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/inode.hpp b/kernel/include/kernel/filesystem/ext2/inode.hpp
index 4284e6f..9318008 100644
--- a/kernel/include/kernel/filesystem/ext2/inode.hpp
+++ b/kernel/include/kernel/filesystem/ext2/inode.hpp
@@ -11,6 +11,8 @@
 
 namespace kernel::filesystem::ext2
 {
+  struct filesystem;
+
   struct [[gnu::packed]] inode_data
   {
     uint16_t mode;
@@ -35,12 +37,13 @@ namespace kernel::filesystem::ext2
 
   struct inode : kernel::filesystem::inode
   {
-    inode();
+    explicit inode(filesystem * fs);
 
     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;
 
     inode_data m_data{};
+    filesystem * m_filesystem;
   };
 }  // namespace kernel::filesystem::ext2
 
-- 
cgit v1.2.3


From 4a2d4fb3ab38a64c4b10832f5a6318b7240829cc Mon Sep 17 00:00:00 2001
From: Marcel Braun <marcel.braun@ost.ch>
Date: Mon, 6 Apr 2026 11:40:12 +0200
Subject: Implement read data in ext2 inode

---
 kernel/include/kernel/filesystem/ext2/filesystem.hpp | 5 +++--
 kernel/include/kernel/filesystem/filesystem.hpp      | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index 9761903..762f590 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -24,12 +24,13 @@ namespace kernel::filesystem::ext2
     auto lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name)
         -> kstd::shared_ptr<kernel::filesystem::inode> override;
 
+    auto get_block_size() -> size_t;
+    auto map_inode_block_index_to_global_block_number(uint32_t inode_block_index, inode_data data) -> uint32_t;
+
   private:
     auto read_inode(uint32_t inode_number) -> kstd::shared_ptr<kernel::filesystem::ext2::inode>;
-    auto map_inode_block_index_to_global_block_number(uint32_t inode_block_index, inode_data data) -> uint32_t;
     auto read_block_number_at_index(uint32_t block_number, uint32_t index) -> uint32_t;
 
-    auto get_block_size() -> size_t;
     auto get_inode_size() -> size_t;
     auto get_inode_block_count(inode_data const & data) -> uint32_t;
 
diff --git a/kernel/include/kernel/filesystem/filesystem.hpp b/kernel/include/kernel/filesystem/filesystem.hpp
index 1c45377..0f9de9f 100644
--- a/kernel/include/kernel/filesystem/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/filesystem.hpp
@@ -22,6 +22,7 @@ namespace kernel::filesystem
     virtual auto lookup(kstd::shared_ptr<inode> const & parent, std::string_view name) -> kstd::shared_ptr<inode> = 0;
 
     [[nodiscard]] auto root_inode() const -> kstd::shared_ptr<inode> const &;
+    [[nodiscard]] auto device() const -> kstd::shared_ptr<kapi::devices::device> const &;
 
   protected:
     kstd::shared_ptr<inode> m_root_inode{};
-- 
cgit v1.2.3


From 2240b9a36e4a9f6f8291c9271e6aac8f5536dbd7 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Tue, 7 Apr 2026 22:13:49 +0200
Subject: refactoring

---
 kernel/include/kernel/filesystem/ext2/filesystem.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index 762f590..abab0a6 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -34,7 +34,7 @@ namespace kernel::filesystem::ext2
     auto get_inode_size() -> size_t;
     auto get_inode_block_count(inode_data const & data) -> uint32_t;
 
-    superblock m_superblock;
+    superblock m_superblock;  // TODO BA-FS26 initialize
     kstd::vector<block_group_descriptor> m_block_group_descriptors;
   };
 }  // namespace kernel::filesystem::ext2
-- 
cgit v1.2.3


From dd330e7a05905713acfa87ec109956bfe78f78c4 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Wed, 8 Apr 2026 09:31:32 +0200
Subject: add descriptions, some refactoring

---
 .../include/kernel/devices/block_device_utils.hpp  | 29 +++++++++++++-
 kernel/include/kernel/filesystem/dentry.hpp        | 46 ++++++++++++++++++++++
 .../include/kernel/filesystem/devfs/filesystem.hpp | 18 +++++++++
 kernel/include/kernel/filesystem/devfs/inode.hpp   | 22 +++++++++++
 kernel/include/kernel/filesystem/device_inode.hpp  | 31 +++++++++++++++
 .../filesystem/ext2/block_group_descriptor.hpp     |  3 ++
 .../include/kernel/filesystem/ext2/filesystem.hpp  | 29 +++++++++++++-
 kernel/include/kernel/filesystem/ext2/inode.hpp    | 27 +++++++++++++
 .../filesystem/ext2/linked_directory_entry.hpp     |  3 ++
 .../include/kernel/filesystem/ext2/superblock.hpp  |  3 ++
 .../kernel/filesystem/file_descriptor_table.hpp    | 34 ++++++++++++++++
 kernel/include/kernel/filesystem/filesystem.hpp    | 37 +++++++++++++++++
 kernel/include/kernel/filesystem/inode.hpp         | 44 +++++++++++++++++++++
 kernel/include/kernel/filesystem/mount.hpp         | 28 ++++++++++++-
 kernel/include/kernel/filesystem/mount_table.hpp   | 16 +++++++-
 .../kernel/filesystem/open_file_description.hpp    | 28 +++++++++++++
 .../kernel/filesystem/rootfs/filesystem.hpp        | 18 +++++++++
 kernel/include/kernel/filesystem/rootfs/inode.hpp  | 34 ++++++++++++++++
 kernel/include/kernel/filesystem/vfs.hpp           | 31 +++++++++++++++
 19 files changed, 476 insertions(+), 5 deletions(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/devices/block_device_utils.hpp b/kernel/include/kernel/devices/block_device_utils.hpp
index 5e862ba..7b1daec 100644
--- a/kernel/include/kernel/devices/block_device_utils.hpp
+++ b/kernel/include/kernel/devices/block_device_utils.hpp
@@ -9,7 +9,34 @@
 
 namespace kernel::devices::block_device_utils
 {
-  auto read(kstd::shared_ptr<kapi::devices::device> const & device, void * buffer, size_t offset, size_t size) -> size_t;
+  /**
+  @brief Utility functions for block devices, such as reading/writing data at specific offsets. These functions handle
+  the necessary logic to interact with block devices, such as calculating block boundaries and ensuring proper access
+  patterns. They abstract away the details of block device interactions, providing a simple interface for reading and
+  writing data to block devices.
+  */
+
+  /**
+  @brief Reads data from a @p device into a @p buffer, starting at a specific @p offset and for a given @p size.
+  @warning Panics if @p buffer or @p device is null.
+  @param device The block device to read from.
+  @param buffer The buffer to read data into.
+  @param offset The offset on the block device to start reading from.
+  @param size The number of bytes to read.
+  @return The number of bytes actually read, which may be less than the requested size.
+  */
+  auto read(kstd::shared_ptr<kapi::devices::device> const & device, void * buffer, size_t offset, size_t size)
+      -> size_t;
+
+  /**
+  @brief Writes data from a @p buffer to a @p device, starting at a specific @p offset and for a given @p size.
+  @warning Panics if @p buffer or @p device is null.
+  @param device The block device to write to.
+  @param buffer The buffer to write data from.
+  @param offset The offset on the block device to start writing to.
+  @param size The number of bytes to write.
+  @return The number of bytes actually written, which may be less than the requested size.
+  */
   auto write(kstd::shared_ptr<kapi::devices::device> const & device, void const * buffer, size_t offset, size_t size)
       -> size_t;
 }  // namespace kernel::devices::block_device_utils
diff --git a/kernel/include/kernel/filesystem/dentry.hpp b/kernel/include/kernel/filesystem/dentry.hpp
index fc85a7d..72d758f 100644
--- a/kernel/include/kernel/filesystem/dentry.hpp
+++ b/kernel/include/kernel/filesystem/dentry.hpp
@@ -12,23 +12,69 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief Represents a directory entry (dentry) in the filesystem. A dentry is a node in the directory tree that
+  represents a file or directory. It contains a reference to its parent dentry, a reference to the associated real
+  filesystem inode, and a list of child dentries.
+  */
   struct dentry
   {
+    /**
+    @brief Flags for the dentry.
+    */
     enum class dentry_flags : uint32_t
     {
       dcache_mounted = 1 << 15
     };
 
+    /**
+    @brief Create a dentry with the given @p parent, associated @p node, and optional @p name. The dentry is initialized
+    with the provided parent and inode, and the name is stored for lookup purposes.
+    */
     dentry(kstd::shared_ptr<dentry> const & parent, kstd::shared_ptr<inode> const & node, std::string_view name = {});
 
+    /**
+    @brief Get the associated inode.
+    @return A reference to the associated inode.
+    */
     [[nodiscard]] auto get_inode() const -> kstd::shared_ptr<inode> const &;
+
+    /**
+    @brief Get the parent dentry.
+    @return A reference to the parent dentry.
+    */
     [[nodiscard]] auto get_parent() const -> kstd::shared_ptr<dentry> const &;
 
+    /**
+    @brief Add a @p child dentry.
+    @param child The child dentry to add.
+    */
     auto add_child(kstd::shared_ptr<dentry> const & child) -> void;
+
+    /**
+    @brief Find a child dentry by @p name.
+    @param name The name of the child dentry to find.
+    @return A pointer to the found child dentry, or a null pointer if not found.
+    */
     [[nodiscard]] auto find_child(std::string_view name) const -> kstd::shared_ptr<dentry>;
 
+    /**
+    @brief Set a @p flag for the dentry.
+    @param flag The flag to set.
+    */
     auto set_flag(dentry_flags flag) -> void;
+
+    /**
+    @brief Unset a @p flag for the dentry.
+    @param flag The flag to unset.
+    */
     auto unset_flag(dentry_flags flag) -> void;
+
+    /**
+    @brief Check if the dentry has a specific @p flag.
+    @param flag The flag to check.
+    @return True if the dentry has the flag, false otherwise.
+    */
     [[nodiscard]] auto has_flag(dentry_flags flag) const -> bool;
 
   private:
diff --git a/kernel/include/kernel/filesystem/devfs/filesystem.hpp b/kernel/include/kernel/filesystem/devfs/filesystem.hpp
index 3edeabb..60c39cf 100644
--- a/kernel/include/kernel/filesystem/devfs/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/devfs/filesystem.hpp
@@ -13,9 +13,27 @@
 
 namespace kernel::filesystem::devfs
 {
+  /**
+  @brief A filesystem for managing device nodes in the virtual filesystem. This filesystem provides a way to represent
+  devices as files in the /dev directory, allowing user-space applications to interact with devices using standard file
+  operations. The devfs filesystem dynamically creates inodes for devices registered in the system, enabling seamless
+  access to device functionality through the filesystem interface.
+  */
   struct filesystem : kernel::filesystem::filesystem
   {
+    /**
+    @brief Initializes the devfs instance and builds the device inode table.
+    @param device Backing device passed by the generic filesystem interface (not required by devfs).
+    @return 0 on success, -1 on failure.
+    */
     auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override;
+
+    /**
+    @brief Looks up an inode by @p name within a @p parent directory.
+    @param parent The parent directory inode.
+    @param name The name of the inode to look up.
+    @return A pointer to the found inode, or a null pointer if not found.
+    */
     auto lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name)
         -> kstd::shared_ptr<kernel::filesystem::inode> override;
 
diff --git a/kernel/include/kernel/filesystem/devfs/inode.hpp b/kernel/include/kernel/filesystem/devfs/inode.hpp
index 9c11edf..c117bd2 100644
--- a/kernel/include/kernel/filesystem/devfs/inode.hpp
+++ b/kernel/include/kernel/filesystem/devfs/inode.hpp
@@ -7,11 +7,33 @@
 
 namespace kernel::filesystem::devfs
 {
+  /**
+  @brief Inode implementation for the devfs filesystem.
+  This inode represents root device node in the /dev directory.
+  */
   struct inode : kernel::filesystem::inode
   {
+    /**
+    @brief Create a devfs inode. The inode is initialized with the appropriate kind (directory).
+    */
     inode();
 
+    /**
+    @brief Reads from the devfs directory inode.
+    @param buffer Destination buffer.
+    @param offset Read offset in bytes.
+    @param size Number of bytes requested.
+    @return Number of bytes read (always 0 because this inode does not expose file data).
+    */
     auto read(void * buffer, size_t offset, size_t size) const -> size_t override;
+
+    /**
+    @brief Writes to the devfs directory inode.
+    @param buffer Source buffer.
+    @param offset Write offset in bytes.
+    @param size Number of bytes requested.
+    @return Number of bytes written (always 0 because writes are not supported for this inode).
+    */
     auto write(void const * buffer, size_t offset, size_t size) -> size_t override;
   };
 }  // namespace kernel::filesystem::devfs
diff --git a/kernel/include/kernel/filesystem/device_inode.hpp b/kernel/include/kernel/filesystem/device_inode.hpp
index 18a98f5..c33be2a 100644
--- a/kernel/include/kernel/filesystem/device_inode.hpp
+++ b/kernel/include/kernel/filesystem/device_inode.hpp
@@ -2,6 +2,7 @@
 #define TEACH_OS_KERNEL_FILESYSTEM_DEVICE_INODE_HPP
 
 #include "kapi/devices/device.hpp"
+
 #include "kernel/filesystem/inode.hpp"
 
 #include <kstd/memory>
@@ -10,13 +11,43 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief Inode implementation for device inodes in the filesystem. This inode represents a device file that provides
+  access to a device registered in the system. The device inode allows reading from and writing to the associated
+  device.
+  */
   struct device_inode : inode
   {
+    /**
+    @brief Create a device inode with the given @p device.
+    @param device The device to associate with the inode.
+    */
     explicit device_inode(kstd::shared_ptr<kapi::devices::device> const & device);
 
+    /**
+    @brief Read data from the device inode (and in the background from the associated device) into a @p buffer, starting
+    at @p offset and reading @p size bytes.
+    @param buffer The buffer to read data into.
+    @param offset The offset to read from.
+    @param size The number of bytes to read.
+    @return The number of bytes read.
+    */
     auto read(void * buffer, size_t offset, size_t size) const -> size_t override;
+
+    /**
+    @brief Write data to the device inode (and in the background from the associated device) from a @p buffer, starting
+    at @p offset and writing @p size bytes.
+    @param buffer The buffer containing data to write.
+    @param offset The offset to write to.
+    @param size The number of bytes to write.
+    @return The number of bytes written.
+    */
     auto write(void const * buffer, size_t offset, size_t size) -> size_t override;
 
+    /**
+    @brief Get the associated device.
+    @return A reference to the associated device.
+    */
     [[nodiscard]] auto device() const -> kstd::shared_ptr<kapi::devices::device> const &;
 
   private:
diff --git a/kernel/include/kernel/filesystem/ext2/block_group_descriptor.hpp b/kernel/include/kernel/filesystem/ext2/block_group_descriptor.hpp
index 2ff91d9..7fbba3f 100644
--- a/kernel/include/kernel/filesystem/ext2/block_group_descriptor.hpp
+++ b/kernel/include/kernel/filesystem/ext2/block_group_descriptor.hpp
@@ -6,6 +6,9 @@
 
 namespace kernel::filesystem::ext2
 {
+  /**
+  @brief Represents a block group descriptor in the ext2 filesystem.
+  */
   struct [[gnu::packed]] block_group_descriptor
   {
     uint32_t block_bitmap;
diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index abab0a6..32374dc 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -18,13 +18,40 @@
 
 namespace kernel::filesystem::ext2
 {
+  /**
+  @brief A filesystem implementation for the ext2 filesystem format. This class provides methods for mounting an ext2
+  filesystem, and looking up inodes.
+  */
   struct filesystem : kernel::filesystem::filesystem
   {
+    /**
+    @brief Initializes the ext2 filesystem with the given @p device.
+    @param device The device to mount.
+    @return 0 on success, negative error code on failure.
+    */
     auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override;
+
+    /**
+    @brief Looks up an inode by @p name within a @p parent directory.
+    @param parent The parent directory inode.
+    @param name The name of the inode to look up.
+    @return A pointer to the found inode, or a null pointer if not found.
+    */
     auto lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name)
         -> kstd::shared_ptr<kernel::filesystem::inode> override;
 
+    /**
+    @brief Gets the size of a block in the filesystem.
+    @return The size of a block in bytes.
+    */
     auto get_block_size() -> size_t;
+
+    /**
+    @brief Maps an inode block index to a global block number.
+    @param inode_block_index The index of the block within the inode.
+    @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;
 
   private:
@@ -34,7 +61,7 @@ namespace kernel::filesystem::ext2
     auto get_inode_size() -> size_t;
     auto get_inode_block_count(inode_data const & data) -> uint32_t;
 
-    superblock m_superblock;  // TODO BA-FS26 initialize
+    superblock m_superblock{};
     kstd::vector<block_group_descriptor> m_block_group_descriptors;
   };
 }  // namespace kernel::filesystem::ext2
diff --git a/kernel/include/kernel/filesystem/ext2/inode.hpp b/kernel/include/kernel/filesystem/ext2/inode.hpp
index 9318008..a1645cd 100644
--- a/kernel/include/kernel/filesystem/ext2/inode.hpp
+++ b/kernel/include/kernel/filesystem/ext2/inode.hpp
@@ -13,6 +13,9 @@ namespace kernel::filesystem::ext2
 {
   struct filesystem;
 
+  /**
+  @brief Represents the data associated with an ext2 inode.
+  */
   struct [[gnu::packed]] inode_data
   {
     uint16_t mode;
@@ -37,12 +40,36 @@ namespace kernel::filesystem::ext2
 
   struct inode : kernel::filesystem::inode
   {
+    /**
+    @brief Create an ext2 inode associated with the given filesystem.
+    */
     explicit inode(filesystem * fs);
 
+    /**
+    @brief Reads from the ext2 inode into a @p buffer, starting at the specified @p offset and for a given @p size.
+    @param buffer Destination buffer.
+    @param offset Read offset in bytes.
+    @param size Number of bytes requested.
+    @return Number of bytes read.
+    */
     auto read(void * buffer, size_t offset, size_t size) const -> size_t override;
+
+    /**
+    @brief Writes to the ext2 inode into a @p buffer, starting at the specified @p offset and for a given @p size.
+    @warning This method is not implemented yet and will panic if called.
+    @param buffer Source buffer.
+    @param offset Write offset in bytes.
+    @param size Number of bytes requested.
+    @return Number of bytes written.
+    */
     auto write(void const * buffer, size_t offset, size_t size) -> size_t override;
 
+    /**
+    @brief The raw inode data as read from the disk.
+    */
     inode_data m_data{};
+
+  private:
     filesystem * m_filesystem;
   };
 }  // namespace kernel::filesystem::ext2
diff --git a/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp b/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
index 76eb6f5..4097cbb 100644
--- a/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
+++ b/kernel/include/kernel/filesystem/ext2/linked_directory_entry.hpp
@@ -6,6 +6,9 @@
 
 namespace kernel::filesystem::ext2
 {
+  /**
+  @brief Represents a linked directory entry in the ext2 filesystem.
+  */
   struct [[gnu::packed]] linked_directory_entry
   {
     uint32_t inode;
diff --git a/kernel/include/kernel/filesystem/ext2/superblock.hpp b/kernel/include/kernel/filesystem/ext2/superblock.hpp
index 8e57ae7..41ad935 100644
--- a/kernel/include/kernel/filesystem/ext2/superblock.hpp
+++ b/kernel/include/kernel/filesystem/ext2/superblock.hpp
@@ -6,6 +6,9 @@
 
 namespace kernel::filesystem::ext2
 {
+  /**
+  @brief Represents the superblock in the ext2 filesystem.
+  */
   struct [[gnu::packed]] superblock
   {
     uint32_t inodes_count;
diff --git a/kernel/include/kernel/filesystem/file_descriptor_table.hpp b/kernel/include/kernel/filesystem/file_descriptor_table.hpp
index 91e2960..5d52c19 100644
--- a/kernel/include/kernel/filesystem/file_descriptor_table.hpp
+++ b/kernel/include/kernel/filesystem/file_descriptor_table.hpp
@@ -8,15 +8,49 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief A table for managing file descriptors in the filesystem. This class provides methods for adding, retrieving,
+  and removing open file descriptions.
+  */
   struct file_descriptor_table
   {
+    /**
+    @brief Initialize the global file descriptor table. This method creates the singleton instance of the file
+    descriptor table.
+    @warning Panics if called more than once.
+    */
     auto static init() -> void;
+
+    /**
+    @brief Get the global file descriptor table instance.
+    @return A reference to the global file descriptor table.
+    @warning Panics if the file descriptor table has not been initialized.
+    */
     auto static get() -> file_descriptor_table &;
 
+    /**
+    @brief Destructor for the file descriptor table.
+    */
     ~file_descriptor_table() = default;
 
+    /**
+    @brief Add a file to the descriptor table.
+    @param f The file description to add.
+    @return The file descriptor index assigned to the file, or -1 on failure.
+    */
     auto add_file(kstd::shared_ptr<open_file_description> const & f) -> int;
+
+    /**
+    @brief Get a file from the descriptor table.
+    @param fd The file descriptor index to retrieve.
+    @return A pointer to the requested file description, or a null pointer if not found.
+    */
     [[nodiscard]] auto get_file(int fd) const -> kstd::shared_ptr<open_file_description>;
+
+    /**
+    @brief Remove a file from the descriptor table.
+    @param fd The file descriptor index to remove.
+    */
     auto remove_file(int fd) -> void;
 
   private:
diff --git a/kernel/include/kernel/filesystem/filesystem.hpp b/kernel/include/kernel/filesystem/filesystem.hpp
index 0f9de9f..f855380 100644
--- a/kernel/include/kernel/filesystem/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/filesystem.hpp
@@ -12,16 +12,53 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief A base class for implementing filesystems in the kernel. This class provides a common interface for managing
+  files and directories within the virtual filesystem.
+  */
   struct filesystem
   {
+    /**
+    @brief Virtual destructor for the filesystem.
+    */
     virtual ~filesystem() = default;
 
+    /**
+    @brief Probes the given @p device to determine if it contains a recognizable filesystem, and if so, mounts it and
+    returns a pointer to the mounted filesystem instance. This method iterates through known filesystem types and
+    attempts to initialize it with the device until the mount was successful or all types have been tried.
+    @param device The device to probe and mount.
+    @return A pointer to the mounted filesystem instance if successful, or a null pointer if no recognizable filesystem
+    is found on the device.
+    @warning Panics if @p device is null.
+    */
     auto static probe_and_mount(kstd::shared_ptr<kapi::devices::device> const & device) -> kstd::shared_ptr<filesystem>;
 
+    /**
+    @brief Initializes the filesystem with the given @p device.
+    @param device The device to mount.
+    @return 0 on success, or a negative error code on failure.
+    */
     virtual auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int;
+
+    /**
+    @brief Looks up a child inode within the given @p parent inode with the specified @p name. This method must be
+    implemented by concrete filesystem subclasses to provide the logic for traversing the filesystem structure and
+    finding the requested inode.
+    @param parent The parent inode.
+    @param name The name of the child inode to look up.
+    @return A pointer to the requested child inode, or a null pointer if not found.
+    */
     virtual auto lookup(kstd::shared_ptr<inode> const & parent, std::string_view name) -> kstd::shared_ptr<inode> = 0;
 
+    /**
+    @brief Returns a reference to the root inode of the filesystem.
+    */
     [[nodiscard]] auto root_inode() const -> kstd::shared_ptr<inode> const &;
+
+    /**
+    @brief Returns a reference to the device associated with the filesystem.
+    */
     [[nodiscard]] auto device() const -> kstd::shared_ptr<kapi::devices::device> const &;
 
   protected:
diff --git a/kernel/include/kernel/filesystem/inode.hpp b/kernel/include/kernel/filesystem/inode.hpp
index 59207df..7237184 100644
--- a/kernel/include/kernel/filesystem/inode.hpp
+++ b/kernel/include/kernel/filesystem/inode.hpp
@@ -5,8 +5,14 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief Represents an inode in the filesystem.
+  */
   struct inode
   {
+    /**
+    @brief Represents the kind of an inode.
+    */
     enum class inode_kind
     {
       regular,
@@ -14,15 +20,53 @@ namespace kernel::filesystem
       device
     };
 
+    /**
+    @brief Create an inode with the given @p kind.
+    @param kind The kind of the inode.
+    */
     explicit inode(inode_kind kind);
 
+    /**
+    @brief Virtual destructor for the inode.
+    */
     virtual ~inode() = default;
 
+    /**
+    @brief Reads from the inode into a @p buffer, starting at the specified @p offset and for a given @p size. This
+    method must be implemented by concrete inode subclasses.
+    @param buffer Destination buffer.
+    @param offset Read offset in bytes.
+    @param size Number of bytes requested.
+    @return Number of bytes read.
+    */
     virtual auto read(void * buffer, size_t offset, size_t size) const -> size_t = 0;
+
+    /**
+    @brief Writes to the inode into a @p buffer, starting at the specified @p offset and for a given @p size. This
+    method must be implemented by concrete inode subclasses.
+    @param buffer Source buffer.
+    @param offset Write offset in bytes.
+    @param size Number of bytes to write.
+    @return Number of bytes written.
+    */
     virtual auto write(void const * buffer, size_t offset, size_t size) -> size_t = 0;
 
+    /**
+    @brief Returns whether the inode is a directory.
+    @return true if the inode is a directory, false otherwise.
+    */
     [[nodiscard]] auto is_directory() const -> bool;
+
+    /**
+    @brief Returns whether the inode is a regular file.
+    @return true if the inode is a regular file, false otherwise.
+    */
     [[nodiscard]] auto is_regular() const -> bool;
+
+    /**
+    @brief Returns whether the inode is a device.
+    @return true if the inode is a device, false otherwise.
+    */
     [[nodiscard]] auto is_device() const -> bool;
 
     // TODO BA-FS26 improve inode_kind really needed?
diff --git a/kernel/include/kernel/filesystem/mount.hpp b/kernel/include/kernel/filesystem/mount.hpp
index a054750..3e3c69f 100644
--- a/kernel/include/kernel/filesystem/mount.hpp
+++ b/kernel/include/kernel/filesystem/mount.hpp
@@ -11,15 +11,41 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief Represents a mounted filesystem in the kernel.
+  */
   struct mount
   {
+    /**
+    @brief Creates a mount for the given @p filesystem at the specified @p mount_path. The @p mount_dentry represents
+    the dentry where the filesystem is mounted, and the @p root_dentry represents the root dentry of the mounted
+    filesystem.
+    @param mount_dentry The dentry where the filesystem is mounted.
+    @param root_dentry The root dentry of the mounted filesystem.
+    @param fs The filesystem instance being mounted.
+    @param mount_path The path at which the filesystem is mounted.
+    */
     mount(kstd::shared_ptr<dentry> const & mount_dentry, kstd::shared_ptr<dentry> const & root_dentry,
           kstd::shared_ptr<filesystem> const & fs, std::string_view mount_path);
 
-    [[nodiscard]] auto get_mount_dentry() const -> kstd::shared_ptr<dentry>;
+    /**
+    @brief Get the dentry where the filesystem is mounted.
+    */
+    [[nodiscard]] auto get_mount_dentry() const -> kstd::shared_ptr<dentry> const &;
+
+    /**
+    @brief Get the root dentry of the mounted filesystem.
+    */
     [[nodiscard]] auto root_dentry() const -> kstd::shared_ptr<dentry> const &;
 
+    /**
+    @brief Get the filesystem instance being mounted.
+    */
     [[nodiscard]] auto get_filesystem() const -> kstd::shared_ptr<filesystem> const &;
+
+    /**
+    @brief Get the path at which the filesystem is mounted.
+    */
     [[nodiscard]] auto get_mount_path() const -> std::string_view;
 
   private:
diff --git a/kernel/include/kernel/filesystem/mount_table.hpp b/kernel/include/kernel/filesystem/mount_table.hpp
index 6dc2218..a8ef59e 100644
--- a/kernel/include/kernel/filesystem/mount_table.hpp
+++ b/kernel/include/kernel/filesystem/mount_table.hpp
@@ -10,11 +10,23 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief A table for managing mounted filesystems in the kernel.
+  */
   struct mount_table
   {
-  public:
-    void add_mount(kstd::shared_ptr<mount>);
+    /**
+    @brief Adds a mount to the table.
+    @param mount The mount to add.
+    */
+    void add_mount(kstd::shared_ptr<mount> const & mount);
 
+    /**
+    @brief Finds the mount with the longest prefix matching the given @p path. This method is used to determine which
+    mounted filesystem should handle a given path lookup.
+    @param path The path to match against the mount paths in the table.
+    @return A pointer to the mount with the longest matching prefix, or a null pointer if no mount matches the path.
+    */
     [[nodiscard]] auto find_longest_prefix_mount(std::string_view path) const -> kstd::shared_ptr<mount>;
 
   private:
diff --git a/kernel/include/kernel/filesystem/open_file_description.hpp b/kernel/include/kernel/filesystem/open_file_description.hpp
index 45719cf..ed878a7 100644
--- a/kernel/include/kernel/filesystem/open_file_description.hpp
+++ b/kernel/include/kernel/filesystem/open_file_description.hpp
@@ -9,13 +9,41 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief Represents an open file description in the filesystem. This class encapsulates the state of an open file,
+  including a reference to the associated inode and the current file offset.
+  */
   struct open_file_description
   {
+    /**
+    @brief Constructs an open file description for the given @p inode.
+    @param inode The inode to associate with the open file description.
+    */
     explicit open_file_description(kstd::shared_ptr<inode> const & inode);
 
+    /**
+    @brief Destructor for the open file description.
+    */
     ~open_file_description() = default;
 
+    /**
+    @brief Reads data from the open file description into a @p buffer, starting at the current file offset and for a
+    given
+    @p size. The file offset is advanced by the number of bytes read.
+    @param buffer The buffer to read data into.
+    @param size The number of bytes to read.
+    @return The number of bytes read.
+    */
     auto read(void * buffer, size_t size) -> size_t;
+
+    /**
+    @brief Writes data to the open file description from a @p buffer, starting at the current file offset and for a
+    given
+    @p size. The file offset is advanced by the number of bytes written.
+    @param buffer The buffer to write data from.
+    @param size The number of bytes to write.
+    @return The number of bytes written.
+    */
     auto write(void const * buffer, size_t size) -> size_t;
 
   private:
diff --git a/kernel/include/kernel/filesystem/rootfs/filesystem.hpp b/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
index 7931d87..b7e7c6f 100644
--- a/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
@@ -14,9 +14,27 @@
 
 namespace kernel::filesystem::rootfs
 {
+  /**
+  @brief A filesystem for the root filesystem. This filesystem provides access to the root directory and its contents,
+  which are typically populated by the init process during system startup. The rootfs filesystem serves as the top-level
+  directory in the filesystem hierarchy. It is responsible for providing a stable and consistent interface to the root
+  directory.
+  */
   struct filesystem : kernel::filesystem::filesystem
   {
+    /**
+    @brief Initializes the rootfs filesystem with the given @p device.
+    @param device The device to mount (not required by rootfs).
+    @return 0 on success, negative error code on failure.
+    */
     auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override;
+
+    /**
+    @brief Looks up an inode by @p name within a @p parent directory.
+    @param parent The parent directory inode.
+    @param name The name of the inode to look up.
+    @return A pointer to the found inode, or a null pointer if not found.
+    */
     auto lookup(kstd::shared_ptr<kernel::filesystem::inode> const & parent, std::string_view name)
         -> kstd::shared_ptr<kernel::filesystem::inode> override;
   };
diff --git a/kernel/include/kernel/filesystem/rootfs/inode.hpp b/kernel/include/kernel/filesystem/rootfs/inode.hpp
index 24d3e6b..469e47a 100644
--- a/kernel/include/kernel/filesystem/rootfs/inode.hpp
+++ b/kernel/include/kernel/filesystem/rootfs/inode.hpp
@@ -13,14 +13,48 @@
 
 namespace kernel::filesystem::rootfs
 {
+  /**
+  @brief Represents an inode in the rootfs filesystem. This inode represents a directory in the root filesystem and
+  maintains a list of child inodes corresponding to files and subdirectories within the root directory. The rootfs inode
+  provides methods for reading and writing data (which are no-ops for the root directory), as well as adding and looking
+  up child inodes by name.
+  */
   struct inode : kernel::filesystem::inode
   {
+    /**
+    @brief Create a rootfs inode. The inode is initialized with the appropriate kind (directory).
+    */
     inode();
 
+    /**
+    @brief Reads from the rootfs directory inode.
+    @param buffer Destination buffer.
+    @param offset Read offset in bytes.
+    @param size Number of bytes requested.
+    @return Number of bytes read (always 0 because this inode does not expose file data).
+    */
     auto read(void * buffer, size_t offset, size_t size) const -> size_t override;
+
+    /**
+    @brief Writes to the rootfs directory inode.
+    @param buffer Source buffer.
+    @param offset Write offset in bytes.
+    @param size Number of bytes requested.
+    @return Number of bytes written (always 0 because writes are not supported for this inode).
+    */
     auto write(void const * buffer, size_t offset, size_t size) -> size_t override;
 
+    /**
+    @brief Adds a child inode to the rootfs directory inode with the specified @p name.
+    @param name The name of the child inode.
+    */
     auto add_child(std::string_view name) -> void;
+
+    /**
+    @brief Looks up a child inode by @p name.
+    @param name The name of the child inode to look up.
+    @return A pointer to the found child inode, or a null pointer if not found.
+    */
     auto lookup_child(std::string_view name) -> kstd::shared_ptr<inode>;
 
   private:
diff --git a/kernel/include/kernel/filesystem/vfs.hpp b/kernel/include/kernel/filesystem/vfs.hpp
index 5823a83..2d05765 100644
--- a/kernel/include/kernel/filesystem/vfs.hpp
+++ b/kernel/include/kernel/filesystem/vfs.hpp
@@ -12,14 +12,45 @@
 
 namespace kernel::filesystem
 {
+  /**
+  @brief The virtual filesystem (VFS) is responsible for managing mounted filesystems and providing a unified interface
+  for file operations across different filesystem types. The VFS maintains a mount table to keep track of mounted
+  filesystems and their associated mount points. It provides methods for opening files by path, which involvesresolving
+  the path to the appropriate mounted filesystem and delegating the file operation to that filesystem's implementation.
+  */
   struct vfs
   {
+    /**
+    @brief Initialize the virtual filesystem.
+    @warning Panics if the VFS has already been initialized.
+    */
     auto static init() -> void;
+
+    /**
+    @brief Get the singleton instance of the virtual filesystem.
+    @return A reference to the VFS instance.
+    @warning Panics if the VFS has not been initialized yet.
+    */
     auto static get() -> vfs &;
 
+    /**
+    @brief Destructor for the VFS.
+    */
     ~vfs() = default;
 
+    /**
+    @brief Open a file by its @p path. This method resolves the path and creates an open file description.
+    @param path The path to the file to open.
+    @return A shared pointer to the open file description or a null pointer if the file could not be opened.
+    */
     auto open(std::string_view path) -> kstd::shared_ptr<open_file_description>;
+
+    /**
+    @brief Mount a @p filesystem at a specific @p path.
+    @param path The path where the filesystem should be mounted.
+    @param filesystem The filesystem to mount.
+    @return 0 on success, or a negative error code on failure.
+    */
     auto do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> int;
 
   private:
-- 
cgit v1.2.3


From 2793770dc6eba30b73b4a4993618d2cbe184790e Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Wed, 8 Apr 2026 15:21:10 +0200
Subject: implement unmount, improve error codes

---
 .../include/kernel/filesystem/devfs/filesystem.hpp |  4 ++--
 .../include/kernel/filesystem/ext2/filesystem.hpp  |  4 ++--
 kernel/include/kernel/filesystem/filesystem.hpp    | 12 +++++++++--
 kernel/include/kernel/filesystem/mount.hpp         | 10 +++++++++-
 kernel/include/kernel/filesystem/mount_table.hpp   | 21 +++++++++++++++++++-
 .../kernel/filesystem/rootfs/filesystem.hpp        |  4 ++--
 kernel/include/kernel/filesystem/vfs.hpp           | 23 ++++++++++++++++++++--
 7 files changed, 66 insertions(+), 12 deletions(-)

(limited to 'kernel/include')

diff --git a/kernel/include/kernel/filesystem/devfs/filesystem.hpp b/kernel/include/kernel/filesystem/devfs/filesystem.hpp
index 60c39cf..137eca3 100644
--- a/kernel/include/kernel/filesystem/devfs/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/devfs/filesystem.hpp
@@ -24,9 +24,9 @@ namespace kernel::filesystem::devfs
     /**
     @brief Initializes the devfs instance and builds the device inode table.
     @param device Backing device passed by the generic filesystem interface (not required by devfs).
-    @return 0 on success, -1 on failure.
+    @return The result of the mount operation.
     */
-    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override;
+    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result override;
 
     /**
     @brief Looks up an inode by @p name within a @p parent directory.
diff --git a/kernel/include/kernel/filesystem/ext2/filesystem.hpp b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
index 32374dc..65324c8 100644
--- a/kernel/include/kernel/filesystem/ext2/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/ext2/filesystem.hpp
@@ -27,9 +27,9 @@ namespace kernel::filesystem::ext2
     /**
     @brief Initializes the ext2 filesystem with the given @p device.
     @param device The device to mount.
-    @return 0 on success, negative error code on failure.
+    @return The result of the mount operation.
     */
-    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override;
+    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result override;
 
     /**
     @brief Looks up an inode by @p name within a @p parent directory.
diff --git a/kernel/include/kernel/filesystem/filesystem.hpp b/kernel/include/kernel/filesystem/filesystem.hpp
index f855380..ef6929a 100644
--- a/kernel/include/kernel/filesystem/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/filesystem.hpp
@@ -18,6 +18,14 @@ namespace kernel::filesystem
   */
   struct filesystem
   {
+    enum class operation_result : int
+    {
+      success = 0,
+      invalid_magic_number = -1,
+      invalid_root_inode = -2,
+      unmount_failed = -3
+    };
+
     /**
     @brief Virtual destructor for the filesystem.
     */
@@ -37,9 +45,9 @@ namespace kernel::filesystem
     /**
     @brief Initializes the filesystem with the given @p device.
     @param device The device to mount.
-    @return 0 on success, or a negative error code on failure.
+    @return The result of the mount operation.
     */
-    virtual auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int;
+    virtual auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result;
 
     /**
     @brief Looks up a child inode within the given @p parent inode with the specified @p name. This method must be
diff --git a/kernel/include/kernel/filesystem/mount.hpp b/kernel/include/kernel/filesystem/mount.hpp
index 3e3c69f..0ac6b2f 100644
--- a/kernel/include/kernel/filesystem/mount.hpp
+++ b/kernel/include/kernel/filesystem/mount.hpp
@@ -24,9 +24,11 @@ namespace kernel::filesystem
     @param root_dentry The root dentry of the mounted filesystem.
     @param fs The filesystem instance being mounted.
     @param mount_path The path at which the filesystem is mounted.
+    @param parent_mount The parent mount that this mount is attached beneath.
     */
     mount(kstd::shared_ptr<dentry> const & mount_dentry, kstd::shared_ptr<dentry> const & root_dentry,
-          kstd::shared_ptr<filesystem> const & fs, std::string_view mount_path);
+          kstd::shared_ptr<filesystem> const & fs, std::string_view mount_path,
+          kstd::shared_ptr<mount> const & parent_mount);
 
     /**
     @brief Get the dentry where the filesystem is mounted.
@@ -48,11 +50,17 @@ namespace kernel::filesystem
     */
     [[nodiscard]] auto get_mount_path() const -> std::string_view;
 
+    /**
+    @brief Get the parent mount that this mount was attached beneath.
+    */
+    [[nodiscard]] auto get_parent_mount() const -> kstd::shared_ptr<mount> const &;
+
   private:
     kstd::string m_mount_path;
     kstd::shared_ptr<dentry> m_mount_dentry;
     kstd::shared_ptr<dentry> m_root_dentry;
     kstd::shared_ptr<filesystem> m_filesystem{};
+    kstd::shared_ptr<mount> m_parent_mount{};
   };
 }  // namespace kernel::filesystem
 
diff --git a/kernel/include/kernel/filesystem/mount_table.hpp b/kernel/include/kernel/filesystem/mount_table.hpp
index a8ef59e..a5cdde6 100644
--- a/kernel/include/kernel/filesystem/mount_table.hpp
+++ b/kernel/include/kernel/filesystem/mount_table.hpp
@@ -15,11 +15,28 @@ namespace kernel::filesystem
   */
   struct mount_table
   {
+    /**
+    @brief Results for mount table operations.
+    */
+    enum class operation_result : int
+    {
+      removed = 0,
+      has_child_mounts = -1,
+      mount_not_found = -2
+    };
+
     /**
     @brief Adds a mount to the table.
     @param mount The mount to add.
     */
-    void add_mount(kstd::shared_ptr<mount> const & mount);
+    auto add_mount(kstd::shared_ptr<mount> const & mount) -> void;
+
+    /**
+    @brief Removes the topmost mount at the given @p path.
+    @param path The mount path to remove.
+    @return The result of the removal operation.
+    */
+    [[nodiscard]] auto remove_mount(std::string_view path) -> operation_result;
 
     /**
     @brief Finds the mount with the longest prefix matching the given @p path. This method is used to determine which
@@ -30,6 +47,8 @@ namespace kernel::filesystem
     [[nodiscard]] auto find_longest_prefix_mount(std::string_view path) const -> kstd::shared_ptr<mount>;
 
   private:
+    [[nodiscard]] auto has_child_mounts(kstd::shared_ptr<mount> const & parent_mount) const -> bool;
+
     kstd::vector<kstd::shared_ptr<mount>> m_mounts;
   };
 }  // namespace kernel::filesystem
diff --git a/kernel/include/kernel/filesystem/rootfs/filesystem.hpp b/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
index b7e7c6f..0155c41 100644
--- a/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
+++ b/kernel/include/kernel/filesystem/rootfs/filesystem.hpp
@@ -25,9 +25,9 @@ namespace kernel::filesystem::rootfs
     /**
     @brief Initializes the rootfs filesystem with the given @p device.
     @param device The device to mount (not required by rootfs).
-    @return 0 on success, negative error code on failure.
+    @return The result of the mount operation.
     */
-    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> int override;
+    auto mount(kstd::shared_ptr<kapi::devices::device> const & device) -> operation_result override;
 
     /**
     @brief Looks up an inode by @p name within a @p parent directory.
diff --git a/kernel/include/kernel/filesystem/vfs.hpp b/kernel/include/kernel/filesystem/vfs.hpp
index 2d05765..4dd2a83 100644
--- a/kernel/include/kernel/filesystem/vfs.hpp
+++ b/kernel/include/kernel/filesystem/vfs.hpp
@@ -20,6 +20,18 @@ namespace kernel::filesystem
   */
   struct vfs
   {
+    /**
+    @brief Results for VFS operations.
+    */
+    enum class operation_result : int
+    {
+      success = 0,
+      invalid_path = -1,
+      mount_point_not_found = -2,
+      filesystem_null = -3,
+      unmount_failed = -4
+    };
+
     /**
     @brief Initialize the virtual filesystem.
     @warning Panics if the VFS has already been initialized.
@@ -49,9 +61,16 @@ namespace kernel::filesystem
     @brief Mount a @p filesystem at a specific @p path.
     @param path The path where the filesystem should be mounted.
     @param filesystem The filesystem to mount.
-    @return 0 on success, or a negative error code on failure.
+    @return The result of the mount operation.
+    */
+    auto do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> operation_result;
+
+    /**
+    @brief Unmount the filesystem mounted at the specified @p path.
+    @param path The path where the filesystem is mounted.
+    @return The result of the unmount operation.
     */
-    auto do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> int;
+    auto unmount(std::string_view path) -> operation_result;
 
   private:
     vfs() = default;
-- 
cgit v1.2.3


From e2c08ddb3d79f946399ca5d3bc07b4e6c4de9328 Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Wed, 8 Apr 2026 16:21:33 +0200
Subject: add dentry tests

---
 kernel/include/kernel/filesystem/dentry.hpp | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

(limited to '