From 0a03abd3d367384c1ae1ad6709f97a9c42ec8a7d Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Fri, 21 Aug 2026 19:32:55 +0200
Subject: kernel/fs: add back-link from inodes to their mount

---
 kernel/kernel/filesystem/inode.cpp | 11 +++++++++++
 kernel/kernel/filesystem/inode.hpp | 21 +++++++++++++++++++++
 kernel/kernel/filesystem/vfs.cpp   |  4 ++++
 3 files changed, 36 insertions(+)

diff --git a/kernel/kernel/filesystem/inode.cpp b/kernel/kernel/filesystem/inode.cpp
index d0762472..26f523c6 100644
--- a/kernel/kernel/filesystem/inode.cpp
+++ b/kernel/kernel/filesystem/inode.cpp
@@ -2,6 +2,7 @@
 
 #include <kapi/filesystem.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/result.hpp>
 
 #include <optional>
@@ -77,4 +78,14 @@ namespace kernel::filesystem
     return std::nullopt;
   }
 
+  auto inode::owning_mount() const noexcept -> kstd::weak_ptr<mount>
+  {
+    return m_owning_mount;
+  }
+
+  auto inode::set_owning_mount(kstd::shared_ptr<mount> const & source) noexcept -> void
+  {
+    m_owning_mount = source;
+  }
+
 }  // namespace kernel::filesystem
\ No newline at end of file
diff --git a/kernel/kernel/filesystem/inode.hpp b/kernel/kernel/filesystem/inode.hpp
index afe15e7d..677c5155 100644
--- a/kernel/kernel/filesystem/inode.hpp
+++ b/kernel/kernel/filesystem/inode.hpp
@@ -3,6 +3,7 @@
 
 #include <kapi/filesystem.hpp>
 
+#include <kstd/memory.hpp>
 #include <kstd/result.hpp>
 #include <kstd/units.hpp>
 
@@ -12,6 +13,8 @@
 
 namespace kernel::filesystem
 {
+  struct mount;
+
   //! An inode in the filesystem.
   //!
   //! Specific filesystems, or other subsystems, may provide their own implementation of this abstract base class. For
@@ -102,6 +105,24 @@ namespace kernel::filesystem
     [[nodiscard]] virtual auto raw_device() const -> std::optional<kapi::filesystem::device_number>;
 
     //! @}
+
+    //! @name Mount Resolution
+    //! @{
+
+    //! Get the mount this inode belongs to.
+    //!
+    //! @return The mount this inode belongs to.
+    [[nodiscard]] auto owning_mount() const noexcept -> kstd::weak_ptr<mount>;
+
+    //! Define which mount this inode belongs to.
+    //!
+    //! @param source The mount this inode belongs to.
+    auto set_owning_mount(kstd::shared_ptr<mount> const & source) noexcept -> void;
+
+    //! @}
+
+  private:
+    kstd::weak_ptr<mount> m_owning_mount{};
   };
 }  // namespace kernel::filesystem
 
diff --git a/kernel/kernel/filesystem/vfs.cpp b/kernel/kernel/filesystem/vfs.cpp
index 0cb46cac..02c577f2 100644
--- a/kernel/kernel/filesystem/vfs.cpp
+++ b/kernel/kernel/filesystem/vfs.cpp
@@ -282,6 +282,8 @@ namespace kernel::filesystem
     {
       if (auto new_inode = fs->create_inode(parent_dentry->get_inode(), name, type, raw_device))
       {
+        (*new_inode)->set_owning_mount(mount_context);
+
         auto new_dentry = kstd::make_shared<dentry>(parent_dentry, *new_inode, name);
         parent_dentry->add_child(new_dentry);
 
@@ -385,6 +387,8 @@ namespace kernel::filesystem
           return kstd::failure(found_inode.error());
         }
 
+        (*found_inode)->set_owning_mount(current_mount);
+
         next_dentry = kstd::make_shared<dentry>(current_dentry, *found_inode, part);
         current_dentry->add_child(next_dentry);
       }
-- 
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