kernel/fs: add type lookup

4 files changed, 32 insertions, 7 deletions

diff --git a/kernel/kernel/filesystem/type_registry.cpp b/kernel/kernel/filesystem/type_registry.cpp
index ad577294..05fb116a 100644
--- a/kernel/kernel/filesystem/type_registry.cpp
+++ b/kernel/kernel/filesystem/type_registry.cpp
@@ -58,6 +58,15 @@ namespace kernel::filesystem
     return *instance;
   }
 
+  auto type_registry::find(std::string_view name) const -> std::optional<pointer>
+  {
+    if (auto it = m_descriptors.find(name); it != m_descriptors.end())
+    {
+      return it->second;
+    }
+    return std::nullopt;
+  }
+
   auto type_registry::add(pointer descriptor) -> bool
   {
     auto result = m_descriptors.emplace(descriptor->name(), descriptor);
diff --git a/kernel/kernel/filesystem/type_registry.hpp b/kernel/kernel/filesystem/type_registry.hpp
index 3572a0d6..11669ab3 100644
--- a/kernel/kernel/filesystem/type_registry.hpp
+++ b/kernel/kernel/filesystem/type_registry.hpp
@@ -9,6 +9,7 @@
 #include <kstd/vector.hpp>
 
 #include <cstddef>
+#include <optional>
 #include <string_view>
 
 namespace kernel::filesystem
@@ -33,6 +34,11 @@ namespace kernel::filesystem
     //! @return @p true iff. the descriptor was successfully added, @p false if not.
     auto add(pointer descriptor) -> bool;
 
+    //! Find a registered type descriptor by name
+    //!
+    //! @param name The name of the filesystem
+    [[nodiscard]] auto find(std::string_view name) const -> std::optional<pointer>;
+
     //! Get all currently registered type descriptors.
     //!
     //! @return A span containing all currently registered filesystem type descriptors.
diff --git a/kernel/kernel/filesystem/vfs.cpp b/kernel/kernel/filesystem/vfs.cpp
index 5b3d2ebe..0cb46cac 100644
--- a/kernel/kernel/filesystem/vfs.cpp
+++ b/kernel/kernel/filesystem/vfs.cpp
@@ -2,7 +2,6 @@
 
 #include <kernel/filesystem/constants.hpp>
 #include <kernel/filesystem/dentry.hpp>
-#include <kernel/filesystem/devfs/filesystem.hpp>
 #include <kernel/filesystem/device_inode.hpp>
 #include <kernel/filesystem/device_number_registry.hpp>
 #include <kernel/filesystem/error.hpp>
@@ -12,7 +11,7 @@
 #include <kernel/filesystem/mount.hpp>
 #include <kernel/filesystem/mount_table.hpp>
 #include <kernel/filesystem/path.hpp>
-#include <kernel/filesystem/rootfs/filesystem.hpp>
+#include <kernel/filesystem/type_registry.hpp>
 
 #include <kapi/filesystem.hpp>
 #include <kapi/system.hpp>
@@ -54,7 +53,13 @@ namespace kernel::filesystem
   vfs::vfs()
   {
     // mount rootfs at /
-    auto root_fs = kstd::make_shared<rootfs::filesystem>();
+    auto root_fs_descriptor = type_registry::get().find("rootfs");
+    if (!root_fs_descriptor)
+    {
+      kapi::system::panic("[OS:FS] rootfs driver is missing!");
+    }
+
+    auto root_fs = (*root_fs_descriptor)->make_instance();
     if (auto result = root_fs->mount(nullptr); !result)
     {
       kapi::system::panic("[FILESYSTEM] failed to mount root FS", result.error());
@@ -65,7 +70,13 @@ namespace kernel::filesystem
     m_mount_table.add_mount(root_mount);
 
     // mount devfs at /dev (inside rootfs, temporary, will be shadowed)
-    auto device_fs = kstd::make_shared<devfs::filesystem>();
+    auto device_fs_descriptor = type_registry::get().find("devfs");
+    if (!device_fs_descriptor)
+    {
+      kapi::system::panic("[OS:FS] devfs driver is missing!");
+    }
+
+    auto device_fs = (*device_fs_descriptor)->make_instance();
     if (auto result = device_fs->mount(nullptr); !result)
     {
       kapi::system::panic("[FILESYSTEM] failed to mount device FS", result.error());
@@ -290,7 +301,7 @@ namespace kernel::filesystem
     m_mount_table.add_mount(new_mount);
   }
 
-  auto vfs::graft_persistent_device_fs(kstd::shared_ptr<devfs::filesystem> const & device_fs) -> void
+  auto vfs::graft_persistent_device_fs(kstd::shared_ptr<filesystem> const & device_fs) -> void
   {
     auto [root_mount_point_dentry, root_mount] = resolve_path_internal("/").value_or(std::pair{nullptr, nullptr});
     if (root_mount_point_dentry && root_mount)
diff --git a/kernel/kernel/filesystem/vfs.hpp b/kernel/kernel/filesystem/vfs.hpp
index 5837f76c..2f30539b 100644
--- a/kernel/kernel/filesystem/vfs.hpp
+++ b/kernel/kernel/filesystem/vfs.hpp
@@ -2,7 +2,6 @@
 #define TEACHOS_KERNEL_FILESYSTEM_VFS_HPP
 
 #include <kernel/filesystem/dentry.hpp>
-#include <kernel/filesystem/devfs/filesystem.hpp>
 #include <kernel/filesystem/filesystem.hpp>
 #include <kernel/filesystem/inode.hpp>
 #include <kernel/filesystem/mount.hpp>
@@ -115,7 +114,7 @@ namespace kernel::filesystem
     auto do_mount_internal(dentry_ptr const & mount_point_dentry, mount_ptr const & parent_mount, fs_ptr const & fs,
                            mount_ptr const & source_mount = nullptr) -> void;
 
-    auto graft_persistent_device_fs(kstd::shared_ptr<devfs::filesystem> const & device_fs) -> void;
+    auto graft_persistent_device_fs(kstd::shared_ptr<filesystem> const & device_fs) -> void;
 
     auto create_inode(std::string_view path, kapi::filesystem::file_type type,
                       std::optional<kapi::filesystem::device_number> raw_device = std::nullopt) -> kstd::result<void>;