From ec6e7077fe349e5df071db95d001e8f72ccfaa69 Mon Sep 17 00:00:00 2001
From: Liav A <liavalb@gmail.com>
Date: Sat, 10 Feb 2024 15:37:34 +0200
Subject: [PATCH] Tests/Kernel: Add tests for verifying proper loop device
 support

---
 Meta/build-root-filesystem.sh   |  4 +++
 Tests/Kernel/CMakeLists.txt     |  1 +
 Tests/Kernel/TestLoopDevice.cpp | 55 +++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+)
 create mode 100644 Tests/Kernel/TestLoopDevice.cpp

diff --git a/Meta/build-root-filesystem.sh b/Meta/build-root-filesystem.sh
index 3f9aa2cf076..2c824f6d252 100755
--- a/Meta/build-root-filesystem.sh
+++ b/Meta/build-root-filesystem.sh
@@ -110,6 +110,10 @@ if [ -f mnt/usr/Tests/Kernel/TestProcFSWrite ]; then
     chown 0:0 mnt/usr/Tests/Kernel/TestProcFSWrite
     chmod 4755 mnt/usr/Tests/Kernel/TestProcFSWrite
 fi
+if [ -f mnt/usr/Tests/Kernel/TestLoopDevice ]; then
+    chown 0:0 mnt/usr/Tests/Kernel/TestLoopDevice
+    chmod 4755 mnt/usr/Tests/Kernel/TestLoopDevice
+fi
 
 if [ -f mnt/res/kernel.map ]; then
     chmod 0400 mnt/res/kernel.map
diff --git a/Tests/Kernel/CMakeLists.txt b/Tests/Kernel/CMakeLists.txt
index 9e49b0487c8..e5c08dcbc6c 100644
--- a/Tests/Kernel/CMakeLists.txt
+++ b/Tests/Kernel/CMakeLists.txt
@@ -50,6 +50,7 @@ set(LIBTEST_BASED_SOURCES
     TestKernelFilePermissions.cpp
     TestKernelPledge.cpp
     TestKernelUnveil.cpp
+    TestLoopDevice.cpp
     TestMemoryDeviceMmap.cpp
     TestMunMap.cpp
     TestProcFS.cpp
diff --git a/Tests/Kernel/TestLoopDevice.cpp b/Tests/Kernel/TestLoopDevice.cpp
new file mode 100644
index 00000000000..2935e8a4931
--- /dev/null
+++ b/Tests/Kernel/TestLoopDevice.cpp
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2024, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/ByteString.h>
+#include <AK/StringView.h>
+#include <Kernel/API/Ioctl.h>
+#include <LibTest/TestCase.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+static int open_loop_device(int loop_device_index)
+{
+    auto loop_device_path = ByteString::formatted("/dev/loop/{}", loop_device_index);
+    return open(loop_device_path.view().characters_without_null_termination(), O_RDONLY);
+}
+
+TEST_CASE(create_attach_and_destory_loop_device)
+{
+    constexpr char const* test_path = "/tmp/create_attach_and_destory_loop_device_test";
+
+    int devctl_fd = open("/dev/devctl", O_RDONLY);
+    VERIFY(devctl_fd >= 0);
+    auto cleanup_devctl_fd_guard = ScopeGuard([&] {
+        close(devctl_fd);
+    });
+
+    u8 buf[0x1000];
+    memset(buf, 0, sizeof(buf));
+    int fd = open(test_path, O_RDWR | O_CREAT, 0644);
+    VERIFY(fd >= 0);
+    auto cleanup_fd_guard = ScopeGuard([&] {
+        close(fd);
+        unlink(test_path);
+    });
+    auto rc = write(fd, buf, sizeof(buf));
+    VERIFY(rc == sizeof(buf));
+
+    int value = fd;
+    auto create_result = ioctl(devctl_fd, DEVCTL_CREATE_LOOP_DEVICE, &value);
+    EXPECT_EQ(create_result, 0);
+
+    auto loop_device_index = value;
+    auto loop_device_fd_or_error = open_loop_device(loop_device_index);
+    EXPECT(loop_device_fd_or_error >= 0);
+    auto cleanup_loop_device_fd_guard = ScopeGuard([&] {
+        close(loop_device_fd_or_error);
+    });
+
+    auto destroy_result = ioctl(devctl_fd, DEVCTL_DESTROY_LOOP_DEVICE, &loop_device_index);
+    EXPECT_EQ(destroy_result, 0);
+}