From 7414148b662a33cf6c69f89b7b0c3162f6880d6c Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Tue, 5 May 2026 20:33:28 +0200
Subject: refactoring mount_table lookup

---
 kernel/include/kernel/filesystem/mount_table.hpp | 10 ++++++++--
 kernel/src/filesystem/mount_table.cpp            |  8 ++++++++
 kernel/src/filesystem/vfs.cpp                    | 10 ++++------
 3 files changed, 20 insertions(+), 8 deletions(-)

(limited to 'kernel')

diff --git a/kernel/include/kernel/filesystem/mount_table.hpp b/kernel/include/kernel/filesystem/mount_table.hpp
index 00277ea..8e57d9e 100644
--- a/kernel/include/kernel/filesystem/mount_table.hpp
+++ b/kernel/include/kernel/filesystem/mount_table.hpp
@@ -39,13 +39,19 @@ namespace kernel::filesystem
     [[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
-    mounted filesystem should handle a given path lookup.
+    @brief Finds the mount with the longest prefix matching the given @p path.
     @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>;
 
+    /**
+    @brief Finds the mount with the exact mount path matching the given @p path.
+    @param path The path to match against the mount paths in the table.
+    @return A pointer to the mount with the exact matching path, or a null pointer if no mount matches the path.
+    */
+    [[nodiscard]] auto find_exact_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;
 
diff --git a/kernel/src/filesystem/mount_table.cpp b/kernel/src/filesystem/mount_table.cpp
index e21e497..965e83b 100644
--- a/kernel/src/filesystem/mount_table.cpp
+++ b/kernel/src/filesystem/mount_table.cpp
@@ -102,4 +102,12 @@ namespace kernel::filesystem
 
     return mount_with_longest_prefix;
   }
+
+  auto mount_table::find_exact_mount(std::string_view path) const -> kstd::shared_ptr<mount>
+  {
+    auto reversed_mounts = std::ranges::reverse_view(m_mounts);
+    auto mount_it =
+        std::ranges::find_if(reversed_mounts, [&](auto const & mount) { return mount->get_mount_path() == path; });
+    return (mount_it != reversed_mounts.end()) ? *mount_it : nullptr;
+  }
 }  // namespace kernel::filesystem
\ No newline at end of file
diff --git a/kernel/src/filesystem/vfs.cpp b/kernel/src/filesystem/vfs.cpp
index 7f21a5c..19f5f48 100644
--- a/kernel/src/filesystem/vfs.cpp
+++ b/kernel/src/filesystem/vfs.cpp
@@ -41,7 +41,6 @@ namespace kernel::filesystem
 
   auto vfs::init_internal() -> void
   {
-    // Mount rootfs at / as the temporary base
     auto root_fs = kstd::make_shared<rootfs::filesystem>();
     root_fs->mount(nullptr);
 
@@ -140,8 +139,8 @@ namespace kernel::filesystem
                               kstd::shared_ptr<filesystem> const & fs) -> void
   {
     auto mount_path = mount_point_dentry->get_full_path();
-
     auto parent_mount = m_mount_table.find_longest_prefix_mount(mount_path.view());
+
     auto new_fs_root =
         kstd::make_shared<dentry>(mount_point_dentry->get_parent(), fs->root_inode(), mount_point_dentry->get_name());
     auto new_mount = kstd::make_shared<mount>(mount_point_dentry, new_fs_root, fs, mount_path.view(), parent_mount);
@@ -156,7 +155,7 @@ namespace kernel::filesystem
     }
 
     // TODO BA-FS26 refactor (get mount by path, no more prefix matching)
-    auto current_mount = m_mount_table.find_longest_prefix_mount("/");
+    auto current_mount = m_mount_table.find_exact_mount("/");
     if (!current_mount)
     {
       kapi::system::panic("[FILESYSTEM] no root mount found.");
@@ -217,8 +216,7 @@ namespace kernel::filesystem
       }
       else if (next_dentry->has_flag(dentry::dentry_flags::mounted))
       {
-        // TODO BA-FS26 really do it like this? or just call "get" without longes_prefix stuff
-        current_mount = m_mount_table.find_longest_prefix_mount(next_dentry->get_full_path().view());
+        current_mount = m_mount_table.find_exact_mount(next_dentry->get_full_path().view());
         if (!current_mount)
         {
           kapi::system::panic("[FILESYSTEM] mount for dentry with mounted flag not found.");
@@ -246,7 +244,7 @@ namespace kernel::filesystem
 
         if (path::is_valid_absolute_path(symbolic_link_path))
         {
-          current_mount = m_mount_table.find_longest_prefix_mount("/");
+          current_mount = m_mount_table.find_exact_mount("/");
           current_dentry = current_mount->root_dentry();
         }
         continue;
-- 
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