[LTP] [PATCH v3] mount_setattr02.c: Check mount_setattr attr propagation

[Wei Gao]

Signed-off-by: Wei Gao <wegao@suse.com>
---
 runtest/syscalls                              |  1 +
 .../kernel/syscalls/mount_setattr/.gitignore  |  1 +
 .../syscalls/mount_setattr/mount_setattr02.c  | 99 +++++++++++++++++++
 3 files changed, 101 insertions(+)
 create mode 100644 testcases/kernel/syscalls/mount_setattr/mount_setattr02.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 839c23d0a..60cbb66b7 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -858,6 +858,7 @@ mount06 mount06
 mount07 mount07
 
 mount_setattr01 mount_setattr01
+mount_setattr02 mount_setattr02
 
 move_mount01 move_mount01
 move_mount02 move_mount02
diff --git a/testcases/kernel/syscalls/mount_setattr/.gitignore b/testcases/kernel/syscalls/mount_setattr/.gitignore
index 52a77b9ca..1654f27de 100644
--- a/testcases/kernel/syscalls/mount_setattr/.gitignore
+++ b/testcases/kernel/syscalls/mount_setattr/.gitignore
@@ -1 +1,2 @@
 /mount_setattr01
+/mount_setattr02
diff --git a/testcases/kernel/syscalls/mount_setattr/mount_setattr02.c b/testcases/kernel/syscalls/mount_setattr/mount_setattr02.c
new file mode 100644
index 000000000..fcc088e3b
--- /dev/null
+++ b/testcases/kernel/syscalls/mount_setattr/mount_setattr02.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2025 SUSE LLC Wei Gao <wegao@suse.com>
+ */
+
+/*\
+ * Basic mount_setattr() test.
+ *
+ * Test basic propagation mount attributes are set correctly.
+ */
+
+#define _GNU_SOURCE
+
+#include <sys/statvfs.h>
+#include "tst_test.h"
+#include "lapi/fsmount.h"
+#include "tst_safe_stdio.h"
+
+static char *tmpdir;
+
+static int mounted;
+
+static bool is_shared_mount(const char *path)
+{
+	FILE *file = SAFE_FOPEN("/proc/self/mountinfo", "r");
+
+	char line[PATH_MAX];
+	bool found = false;
+
+	while (fgets(line, sizeof(line), file)) {
+		char mntpoint[PATH_MAX];
+		char opts[256];
+
+		if (sscanf(line, "%*d %*d %*d:%*d %*s %255s %*s %255s",
+					mntpoint, opts) != 2)
+			continue;
+
+		if (strcmp(mntpoint, path) != 0)
+			continue;
+
+		if (strstr(opts, "shared:") != NULL) {
+			found = true;
+			break;
+		}
+	}
+
+	fclose(file);
+	return found;
+}
+
+static void cleanup(void)
+{
+	if (mounted)
+		SAFE_UMOUNT(tmpdir);
+}
+
+static void setup(void)
+{
+	tmpdir = tst_tmpdir_path();
+	SAFE_UNSHARE(CLONE_NEWNS);
+	SAFE_MOUNT(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0);
+	SAFE_MOUNT("testing", tmpdir, "tmpfs", MS_NOATIME | MS_NODEV, "");
+	mounted = 1;
+}
+
+static void run(void)
+{
+	struct mount_attr attr = {
+		.attr_set       = MOUNT_ATTR_RDONLY | MOUNT_ATTR_NOEXEC | MOUNT_ATTR_RELATIME,
+		.attr_clr       = MOUNT_ATTR__ATIME,
+	};
+
+	TST_EXP_PASS_SILENT(mount_setattr(-1, tmpdir, 0, &attr, sizeof(attr)));
+	TST_EXP_EQ_LI(is_shared_mount(tmpdir), 0);
+
+	attr.propagation = -1;
+	TST_EXP_FAIL_SILENT(mount_setattr(-1, tmpdir, 0, &attr, sizeof(attr)), EINVAL);
+	TST_EXP_EQ_LI(is_shared_mount(tmpdir), 0);
+
+	attr.propagation = MS_SHARED;
+	TST_EXP_PASS_SILENT(mount_setattr(-1, tmpdir, 0, &attr, sizeof(attr)));
+	TST_EXP_EQ_LI(is_shared_mount(tmpdir), 1);
+
+	attr.propagation = MS_PRIVATE;
+	TST_EXP_PASS_SILENT(mount_setattr(-1, tmpdir, 0, &attr, sizeof(attr)));
+	TST_EXP_EQ_LI(is_shared_mount(tmpdir), 0);
+
+	attr.propagation = MS_SLAVE;
+	TST_EXP_PASS_SILENT(mount_setattr(-1, tmpdir, 0, &attr, sizeof(attr)));
+	TST_EXP_EQ_LI(is_shared_mount(tmpdir), 0);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.setup = setup,
+	.cleanup = cleanup,
+	.needs_root = 1,
+	.needs_tmpdir = 1,
+};
-- 
2.35.3