add mount_table tests

2 files changed, 165 insertions, 0 deletions

diff --git a/kernel/CMakeLists.txt b/kernel/CMakeLists.txt
index c00ec14..d7f2cc4 100644
--- a/kernel/CMakeLists.txt
+++ b/kernel/CMakeLists.txt
@@ -133,6 +133,7 @@ else()
         # Filesystem Subsystem Tests
         "src/filesystem/dentry.tests.cpp"
         "src/filesystem/device_inode.tests.cpp"
+        "src/filesystem/mount_table.tests.cpp"
         "src/filesystem/mount.tests.cpp"
 
         # Storage Subsystem Tests
diff --git a/kernel/src/filesystem/mount_table.tests.cpp b/kernel/src/filesystem/mount_table.tests.cpp
new file mode 100644
index 0000000..9f390c6
--- /dev/null
+++ b/kernel/src/filesystem/mount_table.tests.cpp
@@ -0,0 +1,164 @@
+#include "kernel/filesystem/mount_table.hpp"
+
+#include "kernel/filesystem/dentry.hpp"
+#include "kernel/filesystem/mount.hpp"
+#include "kernel/test_support/cpu.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("finding any mount returns null")
+    {
+      REQUIRE(table.find_longest_prefix_mount("/") == nullptr);
+      REQUIRE(table.find_longest_prefix_mount("/any/path") == nullptr);
+    }
+
+    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_inode1 = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto root_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(nullptr, root_inode1, "/");
+    auto mount1 = kstd::make_shared<kernel::filesystem::mount>(root_dentry1, root_dentry1, fs1, "/", nullptr);
+
+    auto fs2 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_inode2 = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto root_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(nullptr, root_inode2, "/");
+    auto mount2 = kstd::make_shared<kernel::filesystem::mount>(root_dentry1, root_dentry2, fs2, "/mnt", nullptr);
+
+    table.add_mount(mount1);
+    table.add_mount(mount2);
+
+    THEN("dentry flags are set correctly for mounted dentries")
+    {
+      REQUIRE(root_dentry1->has_flag(kernel::filesystem::dentry::dentry_flags::dcache_mounted));
+      REQUIRE(root_dentry2->has_flag(kernel::filesystem::dentry::dentry_flags::dcache_mounted));
+    }
+
+    THEN("finding mounts by path returns the correct mount")
+    {
+      REQUIRE(table.find_longest_prefix_mount("/") == mount1);
+      REQUIRE(table.find_longest_prefix_mount("/file") == mount1);
+      REQUIRE(table.find_longest_prefix_mount("/mnt") == mount2);
+      REQUIRE(table.find_longest_prefix_mount("/mnt/file") == mount2);
+      REQUIRE(table.find_longest_prefix_mount("/other") == mount1);
+    }
+
+    THEN("removing a mount that has no child mounts succeeds")
+    {
+      REQUIRE(table.remove_mount("/mnt") == kernel::filesystem::mount_table::operation_result::removed);
+      REQUIRE(!root_dentry2->has_flag(kernel::filesystem::dentry::dentry_flags::dcache_mounted));
+      REQUIRE(table.find_longest_prefix_mount("/mnt") == nullptr);
+    }
+
+    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_inode1 = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto root_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(nullptr, root_inode1, "/");
+    auto mount1 = kstd::make_shared<kernel::filesystem::mount>(root_dentry1, root_dentry1, fs1, "/", nullptr);
+
+    auto fs2 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_inode2 = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto root_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(nullptr, root_inode2, "/");
+    auto mount2 = kstd::make_shared<kernel::filesystem::mount>(root_dentry1, root_dentry2, fs2, "/", mount1);
+
+    table.add_mount(mount1);
+    table.add_mount(mount2);
+
+    THEN("finding mounts by path returns the correct mount based on longest prefix")
+    {
+      REQUIRE(table.find_longest_prefix_mount("/") == mount2);
+      REQUIRE(table.find_longest_prefix_mount("/file") == mount2);
+      REQUIRE(table.find_longest_prefix_mount("/mnt") == mount2);
+      REQUIRE(table.find_longest_prefix_mount("/mnt/file") == mount2);
+      REQUIRE(table.find_longest_prefix_mount("/other") == mount2);
+    }
+
+    THEN("removing the topmost mount with the same path succeeds")
+    {
+      REQUIRE(table.remove_mount("/") == kernel::filesystem::mount_table::operation_result::removed);
+      REQUIRE(!root_dentry2->has_flag(kernel::filesystem::dentry::dentry_flags::dcache_mounted));
+      REQUIRE(table.find_longest_prefix_mount("/") == mount1);
+    }
+  }
+
+  GIVEN("a mount with child mounts")
+  {
+    kernel::filesystem::mount_table table;
+
+    auto fs1 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_inode1 = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto root_dentry1 = kstd::make_shared<kernel::filesystem::dentry>(nullptr, root_inode1, "/");
+    auto mount1 = kstd::make_shared<kernel::filesystem::mount>(root_dentry1, root_dentry1, fs1, "/", nullptr);
+
+    auto fs2 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_inode2 = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto root_dentry2 = kstd::make_shared<kernel::filesystem::dentry>(nullptr, root_inode2, "/");
+    auto mount2 = kstd::make_shared<kernel::filesystem::mount>(root_dentry1, root_dentry2, fs2, "/mnt", mount1);
+
+    auto fs3 = kstd::make_shared<kernel::tests::filesystem::filesystem>();
+    auto root_inode3 = kstd::make_shared<kernel::tests::filesystem::inode>();
+    auto root_dentry3 = kstd::make_shared<kernel::filesystem::dentry>(nullptr, root_inode3, "/");
+    auto mount3 = kstd::make_shared<kernel::filesystem::mount>(root_dentry2, root_dentry3, fs3, "/mnt/submnt", mount2);
+
+    table.add_mount(mount1);
+    table.add_mount(mount2);
+    table.add_mount(mount3);
+
+    THEN("finding mounts by path returns the correct mount based on longest prefix")
+    {
+      REQUIRE(table.find_longest_prefix_mount("/") == mount1);
+      REQUIRE(table.find_longest_prefix_mount("/file") == mount1);
+      REQUIRE(table.find_longest_prefix_mount("/mnt") == mount2);
+      REQUIRE(table.find_longest_prefix_mount("/mnt/file") == mount2);
+      REQUIRE(table.find_longest_prefix_mount("/mnt/submnt") == mount3);
+      REQUIRE(table.find_longest_prefix_mount("/other") == mount1);
+    }
+
+    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(!root_dentry3->has_flag(kernel::filesystem::dentry::dentry_flags::dcache_mounted));
+      REQUIRE(table.find_longest_prefix_mount("/mnt/submnt") == nullptr);
+    }
+  }
+}