implement first draft of a do_mount function

1 files changed, 45 insertions, 4 deletions

diff --git a/kernel/src/filesystem/vfs.cpp b/kernel/src/filesystem/vfs.cpp
index 1bc9ae6..febb844 100644
--- a/kernel/src/filesystem/vfs.cpp
+++ b/kernel/src/filesystem/vfs.cpp
@@ -36,13 +36,12 @@ namespace filesystem
     if (auto boot_device = storage_mgmt.determine_boot_device())
     {
       active_vfs->m_root_fs = kstd::make_shared<ext2::ext2_filesystem>();
-      if (active_vfs->m_root_fs->mount(boot_device) != 0)
+      if (active_vfs->do_mount("/", active_vfs->m_root_fs) != 0)
       {
         kapi::system::panic("[FILESYSTEM] Failed to mount root filesystem.");
       }
 
-      active_vfs->m_root_mount = mount{"/", active_vfs->m_root_fs};
-
+      // TODO BA-FS26 use do_mount when tempdevfs is implemented -> just call /dev/ with all devices in devtempfs
       std::ranges::for_each(storage_mgmt.all_controllers(), [&](auto controller) {
         std::ranges::for_each(controller->all_devices(), [&](auto device) { active_vfs->make_device_node(device); });
       });
@@ -69,8 +68,9 @@ namespace filesystem
     {
       auto node = custody->get_inode();
 
-      if (auto current_inode_file = node->open_file();)
+      if (auto current_inode_file = node->open_file())
       {
+        // TODO BA-FS26 return shared_ptr?
         return open_file_description{current_inode_file};
       }
 
@@ -80,6 +80,45 @@ namespace filesystem
     return std::nullopt;
   }
 
+  auto vfs::do_mount(std::string_view path, kstd::shared_ptr<filesystem> const & filesystem) -> int
+  {
+    if (!filesystem)
+    {
+      return -1;  // TODO BA-FS26 panic or errorcode?
+    }
+
+    if (path.empty() || path.front() != '/')
+    {
+      return -1;  // TODO BA-FS26 panic or errorcode?
+    }
+
+    // TODO BA-FS26 better path validation
+    if ((path.size() > 1 && path.back() == '/') || path.find("//") != std::string_view::npos)
+    {
+      return -1;  // TODO BA-FS26 panic or errorcode?
+    }
+
+    if (path == "/")
+    {
+      m_root_fs = filesystem;
+      m_root_mount = mount{"/", filesystem};
+      return 0;
+    }
+
+    auto existing_mount =
+        std::ranges::find_if(m_mounts, [&](auto const & existing) { return existing.path() == path; });
+    if (existing_mount != m_mounts.end())
+    {
+      *existing_mount = mount{path, filesystem};
+    }
+    else
+    {
+      m_mounts.push_back(mount{path, filesystem});
+    }
+
+    return 0;
+  }
+
   auto vfs::make_device_node(kstd::shared_ptr<devices::device> const & device) -> void
   {
     if (!device)
@@ -94,6 +133,8 @@ namespace filesystem
   {
     // TODO BA-FS26 implement real path resolution with mounts and directories etc.
     // For now, just support device nodes at /dev/<device_name>.
+    // TODO BA-FS26 better path validation
+    // TODO BA-FS26 implement a path parser (maybe in libs?) and use it here and in do_mount
 
     constexpr auto device_prefix = std::string_view{"/dev/"};
     if (path.starts_with(device_prefix))