Refactor mounting of new filesystems and path resolving in vfs

2 files changed, 32 insertions, 24 deletions

diff --git a/kernel/include/kernel/filesystem/vfs.hpp b/kernel/include/kernel/filesystem/vfs.hpp
index 317f2d1..55bf6a4 100644
--- a/kernel/include/kernel/filesystem/vfs.hpp
+++ b/kernel/include/kernel/filesystem/vfs.hpp
@@ -6,6 +6,7 @@
 #include "kernel/filesystem/filesystem.hpp"
 #include "kernel/filesystem/inode.hpp"
 #include "kernel/filesystem/mount.hpp"
+#include "kernel/filesystem/mount_table.hpp"
 #include "kernel/filesystem/open_file_description.hpp"
 
 #include <kstd/memory>
@@ -43,7 +44,7 @@ namespace filesystem
 
     kstd::shared_ptr<filesystem> m_root_fs;
     kstd::shared_ptr<dentry> m_root_dentry;
-    kstd::vector<mount> m_mount_table;
+    mount_table m_mount_table;
   };
 }  // namespace filesystem
 
diff --git a/kernel/src/filesystem/vfs.cpp b/kernel/src/filesystem/vfs.cpp
index 0e8a76d..c77736a 100644
--- a/kernel/src/filesystem/vfs.cpp
+++ b/kernel/src/filesystem/vfs.cpp
@@ -82,9 +82,9 @@ namespace filesystem
     return nullptr;
   }
 
-  auto vfs::do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> int
+  auto vfs::do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & new_filesystem) -> int
   {
-    if (!filesystem)
+    if (!new_filesystem)
     {
       return -1;  // TODO BA-FS26 panic or errorcode?
     }
@@ -100,24 +100,21 @@ namespace filesystem
       return -1;  // TODO BA-FS26 panic or errorcode?
     }
 
-    // if (path == "/")
-    // {
-    //   m_root_fs = filesystem;
-    //   m_root_mount = mount{"/", filesystem};
-    //   return 0;
-    // }
+    auto mount_dentry = resolve_path(path);
 
-    auto existing_mount =
-        std::ranges::find_if(m_mount_table, [&](auto const & existing) { return existing.path() == path; });
-    if (existing_mount != m_mount_table.end())
+    if (!mount_dentry)
     {
-      *existing_mount = mount{path, filesystem};
-    }
-    else
-    {
-      m_mount_table.push_back(mount{path, filesystem});
+      return -1;  // mount point path doesn't exist
     }
 
+    // TODO BA-FS26 check if mount point is already mounted and handle it (unmount old fs, fail, etc.)
+
+    mount_dentry->set_flag(dentry::dentry_flags::dcache_mounted);
+    m_mount_table.add_mount(kstd::make_shared<mount>(mount_dentry, new_filesystem));
+
+    new_filesystem->set_root_dentry(
+        kstd::make_shared<dentry>(mount_dentry->get_parent(), new_filesystem->root_inode()));
+
     return 0;
   }
 
@@ -157,19 +154,29 @@ namespace filesystem
     {
       auto path_parts =
           std::views::split(path, '/') | std::views::filter([](auto const & part) { return !part.empty(); });
-      auto parent = m_root_dentry;
+      auto current_parent = m_root_dentry;
+      auto current_fs = m_root_fs;
 
       for (auto const & part : path_parts)
       {
-        if (auto child = parent->find_child(std::string_view{part}))
+        if (auto child = current_parent->find_child(std::string_view{part}))
         {
-          parent = child;
+          if (child->has_flag(dentry::dentry_flags::dcache_mounted))  // found dentry is a mounted fs
+          {
+            auto found_mount = m_mount_table.find_mount_by_dentry(child);
+            current_fs = found_mount->get_filesystem();
+            current_parent = current_fs->root_dentry();
+          }
+          else
+          {  // found dentry is NOT a mounted fs -> continue path resolution in current fs
+            current_parent = child;
+          }
         }
-        else if (auto found_inode = m_root_fs->lookup(parent->get_inode(), std::string_view{part}))
+        else if (auto found_inode = m_root_fs->lookup(current_parent->get_inode(), std::string_view{part}))
         {
-          auto next_dentry = kstd::make_shared<dentry>(parent, found_inode, std::string_view{part});
-          parent->add_child(next_dentry);
-          parent = next_dentry;
+          auto next_dentry = kstd::make_shared<dentry>(current_parent, found_inode, std::string_view{part});
+          current_parent->add_child(next_dentry);
+          current_parent = next_dentry;
         }
         else
         {