Merge branch 'vfs' into 'develop-BA-FS26'

implement basic vfs

See merge request teachos/kernel!16

1 files changed, 38 insertions, 0 deletions

diff --git a/kernel/src/filesystem/mount_table.cpp b/kernel/src/filesystem/mount_table.cpp
new file mode 100644
index 0000000..b9e57d4
--- /dev/null
+++ b/kernel/src/filesystem/mount_table.cpp
@@ -0,0 +1,38 @@
+#include "kernel/filesystem/mount_table.hpp"
+
+#include "kernel/filesystem/mount.hpp"
+
+#include <kstd/memory>
+
+#include <cstddef>
+#include <string_view>
+
+namespace filesystem
+{
+  void mount_table::add_mount(kstd::shared_ptr<mount> mount)
+  {
+    m_mounts.push_back(mount);
+  }
+
+  auto mount_table::find_longest_prefix_mount(std::string_view path) const -> kstd::shared_ptr<mount>
+  {
+    kstd::shared_ptr<mount> mount_with_longest_prefix = nullptr;
+    std::size_t best_len = 0;
+
+    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 mount_with_longest_prefix;
+  }
+}  // namespace filesystem
\ No newline at end of file