From a6f93bf8df0dbfa7d19aa1168bfc8b052e41c42f Mon Sep 17 00:00:00 2001
From: Lukas Oesch <lukasoesch20@gmail.com>
Date: Sat, 28 Mar 2026 17:28:32 +0100
Subject: fix vfs mount with /dev & /a  and rootfs & devfs

---
 kernel/src/filesystem/mount_table.cpp | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

(limited to 'kernel/src/filesystem/mount_table.cpp')

diff --git a/kernel/src/filesystem/mount_table.cpp b/kernel/src/filesystem/mount_table.cpp
index 681c2b9..b9e57d4 100644
--- a/kernel/src/filesystem/mount_table.cpp
+++ b/kernel/src/filesystem/mount_table.cpp
@@ -1,11 +1,11 @@
 #include "kernel/filesystem/mount_table.hpp"
 
-#include "kernel/filesystem/dentry.hpp"
 #include "kernel/filesystem/mount.hpp"
 
 #include <kstd/memory>
 
-#include <algorithm>
+#include <cstddef>
+#include <string_view>
 
 namespace filesystem
 {
@@ -14,16 +14,25 @@ namespace filesystem
     m_mounts.push_back(mount);
   }
 
-  auto mount_table::get_root_mount() const -> kstd::shared_ptr<mount>
+  auto mount_table::find_longest_prefix_mount(std::string_view path) const -> kstd::shared_ptr<mount>
   {
-    auto it = std::ranges::find_if(m_mounts, [](auto const & mount) { return mount->get_mount_dentry() == nullptr; });
-    return it != m_mounts.end() ? *it : nullptr;
-  }
+    kstd::shared_ptr<mount> mount_with_longest_prefix = nullptr;
+    std::size_t best_len = 0;
 
-  auto mount_table::find_mount_by_dentry(kstd::shared_ptr<dentry> const & dentry) -> kstd::shared_ptr<mount>
-  {
-    auto it = std::ranges::find_if(m_mounts, [&](auto const & mnt) { return mnt->get_mount_dentry() == dentry; });
+    for (auto const & mount : m_mounts)
+    {
+      auto mp = mount->get_mount_path();
+
+      // /a/b/c should match /a/b but not /a/bb or /a/b/c/d, / should match everything
+      bool is_prefix = path.starts_with(mp) && (mp == "/" || path.size() == mp.size() || path[mp.size()] == '/');
+
+      if (is_prefix && mp.size() >= best_len)
+      {
+        mount_with_longest_prefix = mount;
+        best_len = mp.size();
+      }
+    }
 
-    return it != m_mounts.end() ? *it : nullptr;
+    return mount_with_longest_prefix;
   }
 }  // namespace filesystem
\ No newline at end of file
-- 
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