1 files changed, 184 insertions, 0 deletions
diff --git a/kernel/src/filesystem/mount_table.tests.cpp b/kernel/src/filesystem/mount_table.tests.cpp
new file mode 100644
index 0000000..19b47b2
--- /dev/null
+++ b/kernel/src/filesystem/mount_table.tests.cpp
@@ -0,0 +1,184 @@
+#include <kernel/filesystem/mount_table.hpp>
+
+#include <kernel/filesystem/dentry.hpp>
+#include <kernel/filesystem/mount.hpp>
+#include <kernel/test_support/filesystem/filesystem.hpp>
+#include <kernel/test_support/filesystem/inode.hpp>
+
+#include <kstd/memory>
+#include <kstd/print>
+#include <kstd/vector>
+
+#include <catch2/catch_test_macros.hpp>
+
+#include <string_view>
+
+SCENARIO("Mount table construction", "[filesystem][mount_table]")
+{
+  GIVEN("an empty mount table")
+  {
+    kernel::filesystem::mount_table table;
+
+    THEN("removing any mount returns mount_not_found")
+    {
+      REQUIRE(table.remove_mount("/") == kernel::filesystem::mount_table::operation_result::mount_not_found);
+      REQUIRE(table.remove_mount("/any/path") == kernel::filesystem::mount_table::operation_result::mount_not_found);
+    }
+  }
+}
+
+SCENARIO("Adding, finding and removing mounts in the mount table", "[filesystem][mount_table]")
+{
+  GIVEN("a mount table and some mounts")
+  {
+    kernel::filesystem::mount_table table;
+
+    auto fs1 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount1 = kstd::make_shared<kernel::filesystem::mount>(mount_dentry1, root_dentry1, fs1, nullptr, nullptr);
+
+    auto fs2 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/mnt");
+    auto mount2 = kstd::make_shared<kernel::filesystem::mount>(mount_dentry2, root_dentry2, fs2, nullptr, nullptr);
+
+    table.add_mount(mount1);
+    table.add_mount(mount2);
+
+    THEN("dentry flags are set correctly for mounted dentries")
+    {
+      REQUIRE(mount_dentry1->has_flag(kernel::filesystem::dentry::dentry_flags::is_mount_point));
+      REQUIRE(mount_dentry2->has_flag(kernel::filesystem::dentry::dentry_flags::is_mount_point));
+    }
+
+    THEN("finding mounts by exact valid path returns the correct mount")
+    {
+      REQUIRE(table.find_mount("/") == mount1);
+      REQUIRE(table.find_mount("/mnt") == mount2);
+    }
+
+    THEN("finding mounts by exact invalid path returns null")
+    {
+      REQUIRE(table.find_mount("/nonexistent") == nullptr);
+      REQUIRE(table.find_mount("/mnt/file") == nullptr);
+    }
+
+    THEN("removing a mount that has no child mounts succeeds")
+    {
+      REQUIRE(table.remove_mount("/mnt") == kernel::filesystem::mount_table::operation_result::removed);
+      REQUIRE_FALSE(root_dentry2->has_flag(kernel::filesystem::dentry::dentry_flags::is_mount_point));
+    }
+
+    THEN("removing a mount that does not exist returns mount_not_found")
+    {
+      REQUIRE(table.remove_mount("/nonexistent") == kernel::filesystem::mount_table::operation_result::mount_not_found);
+    }
+  }
+
+  GIVEN("multiple mounts with the same path")
+  {
+    kernel::filesystem::mount_table table;
+
+    auto fs1 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount1 = kstd::make_shared<kernel::filesystem::mount>(mount_dentry1, root_dentry1, fs1, nullptr, nullptr);
+
+    auto fs2 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount2 = kstd::make_shared<kernel::filesystem::mount>(mount_dentry2, root_dentry2, fs2, nullptr, nullptr);
+
+    table.add_mount(mount1);
+    table.add_mount(mount2);
+
+    THEN("finding mounts by exact valid path returns the correct mount")
+    {
+      REQUIRE(table.find_mount("/") == mount2);
+    }
+
+    THEN("removing the topmost mount with the same path succeeds")
+    {
+      REQUIRE(table.remove_mount("/") == kernel::filesystem::mount_table::operation_result::removed);
+      REQUIRE_FALSE(root_dentry2->has_flag(kernel::filesystem::dentry::dentry_flags::is_mount_point));
+    }
+  }
+
+  GIVEN("a mount with child mounts")
+  {
+    kernel::filesystem::mount_table table;
+
+    auto fs1 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount1 = kstd::make_shared<kernel::filesystem::mount>(mount_dentry1, root_dentry1, fs1, nullptr, nullptr);
+
+    auto fs2 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(
+        mount_dentry1, kstd::make_shared<kernel::tests::filesystem::inode>(), "mnt");
+    auto mount2 = kstd::make_shared<kernel::filesystem::mount>(mount_dentry2, root_dentry2, fs2, mount1, nullptr);
+
+    auto fs3 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_dentry3 = kstd::make_shared<kernel::filesystem::dentry>(
+        nullptr, kstd::make_shared<kernel::tests::filesystem::inode>(), "/");
+    auto mount_dentry3 = kstd::make_shared<kernel::filesystem::dentry>(
+        mount_dentry2, kstd::make_shared<kernel::tests::filesystem::inode>(), "submnt");
+    auto mount3 = kstd::make_shared<kernel::filesystem::mount>(mount_dentry3, root_dentry3, fs3, mount2, nullptr);
+
+    table.add_mount(mount1);
+    table.add_mount(mount2);
+    table.add_mount(mount3);
+
+    THEN("removing a mount with child mounts returns has_child_mounts")
+    {
+      REQUIRE(table.remove_mount("/") == kernel::filesystem::mount_table::operation_result::has_child_mounts);
+      REQUIRE(table.remove_mount("/mnt") == kernel::filesystem::mount_table::operation_result::has_child_mounts);
+    }
+
+    THEN("removing a leaf mount succeeds")
+    {
+      REQUIRE(table.remove_mount("/mnt/submnt") == kernel::filesystem::mount_table::operation_result::removed);
+      REQUIRE_FALSE(root_dentry3->has_flag(kernel::filesystem::dentry::dentry_flags::is_mount_point));
+    }
+  }
+}
+
+SCENARIO("Mount reference counting", "[filesystem][mount_table]")
+{
+  kernel::filesystem::mount_table table;
+
+  GIVEN("a filesystem and a root dentry")
+  {
+    auto fs = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_inode = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto root_dentry = kstd::make_shared<kernel::filesystem::dentry>(nullptr, root_inode, "/");
+
+    auto source_mount = kstd::make_shared<kernel::filesystem::mount>(root_dentry, root_dentry, fs, nullptr, nullptr);
+    auto mount = kstd::make_shared<kernel::filesystem::mount>(root_dentry, root_dentry, fs, nullptr, source_mount);
+
+    THEN("reference count of source mount is incremented when a mount is added to the mount table and decremented when "
+         "the mount is removed")
+    {
+      REQUIRE(source_mount->ref_count() == 0);
+
+      table.add_mount(mount);
+      REQUIRE(source_mount->ref_count() == 1);
+
+      REQUIRE(table.remove_mount("/") == kernel::filesystem::mount_table::operation_result::removed);
+      REQUIRE(source_mount->ref_count() == 0);
+    }
+  }
+}