[LTP] [PATCH v2 08/10] Add statmount04 test

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

This test verifies that statmount() is correctly reading propagation
from what mount in current namespace using STATMOUNT_PROPAGATE_FROM.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 runtest/syscalls                              |   1 +
 .../kernel/syscalls/statmount/.gitignore      |   1 +
 .../kernel/syscalls/statmount/statmount04.c   | 133 ++++++++++++++++++
 3 files changed, 135 insertions(+)
 create mode 100644 testcases/kernel/syscalls/statmount/statmount04.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 116106521..3c262ca3e 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1540,6 +1540,7 @@ stat04_64 symlink01 -T stat04_64
 statmount01 statmount01
 statmount02 statmount02
 statmount03 statmount03
+statmount04 statmount04
 
 statfs01 statfs01
 statfs01_64 statfs01_64
diff --git a/testcases/kernel/syscalls/statmount/.gitignore b/testcases/kernel/syscalls/statmount/.gitignore
index 2a02bf721..e720050b5 100644
--- a/testcases/kernel/syscalls/statmount/.gitignore
+++ b/testcases/kernel/syscalls/statmount/.gitignore
@@ -1,3 +1,4 @@
 statmount01
 statmount02
 statmount03
+statmount04
diff --git a/testcases/kernel/syscalls/statmount/statmount04.c b/testcases/kernel/syscalls/statmount/statmount04.c
new file mode 100644
index 000000000..cfb0e9962
--- /dev/null
+++ b/testcases/kernel/syscalls/statmount/statmount04.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/**
+ * [Description]
+ *
+ * This test verifies that statmount() is correctly reading propagation from
+ * what mount in current namespace using STATMOUNT_PROPAGATE_FROM.
+ *
+ * [Algorithm]
+ *
+ * * create a mount point
+ * * propagate a mounted folder inside the mount point
+ * * run statmount() on the mount point using STATMOUNT_PROPAGATE_FROM
+ * * read results and check propagated_from parameter contains the propagated
+ *   folder ID
+ */
+
+#include "statmount.h"
+#include "lapi/stat.h"
+#include "lapi/sched.h"
+#include "tst_safe_stdio.h"
+
+#define MNTPOINT "mntpoint"
+#define DIR_A MNTPOINT "/LTP_DIR_A"
+#define DIR_C_SUBFOLDER "/LTP_DIR_A/propagated"
+#define DIR_C (MNTPOINT DIR_C_SUBFOLDER)
+#define DIR_B MNTPOINT "/LTP_DIR_B"
+#define DIR_D MNTPOINT "/LTP_DIR_B/propagated"
+
+static uint64_t peer_group_id;
+static uint64_t dird_id;
+static struct statmount *st_mount;
+
+static int read_peer_group(void)
+{
+	FILE *file;
+	char line[PATH_MAX];
+	char mroot[PATH_MAX];
+	int group = -1;
+
+	file = SAFE_FOPEN("/proc/self/mountinfo", "r");
+
+	while (fgets(line, sizeof(line), file)) {
+		if (sscanf(line, "%*d %*d %*d:%*d %s %*s %*s shared:%d", mroot, &group) != 2)
+			continue;
+
+		if (strcmp(mroot, DIR_C_SUBFOLDER) == 0)
+			break;
+	}
+
+	if (group == -1)
+		tst_brk(TBROK, "Can't reed peer group ID for %s", DIR_C_SUBFOLDER);
+
+	return group;
+}
+
+static void run(void)
+{
+	memset(st_mount, 0, sizeof(struct statmount));
+
+	TST_EXP_PASS(statmount(
+		dird_id,
+		STATMOUNT_PROPAGATE_FROM,
+		st_mount,
+		sizeof(struct statmount),
+		0));
+
+	if (TST_RET == -1)
+		return;
+
+	TST_EXP_EQ_LI(st_mount->mask, STATMOUNT_PROPAGATE_FROM);
+	TST_EXP_EQ_LI(st_mount->size, sizeof(struct statmount));
+	TST_EXP_EQ_LI(st_mount->propagate_from, peer_group_id);
+}
+
+static void setup(void)
+{
+	struct statx sx;
+
+	/* create DIR_A / DIR_C structure with DIR_C mounted */
+	SAFE_MKDIR(DIR_A, 0700);
+	SAFE_MOUNT(DIR_A, DIR_A, "none", MS_BIND, NULL);
+	SAFE_MOUNT("none", DIR_A, "none", MS_SHARED, NULL);
+
+	SAFE_MKDIR(DIR_C, 0700);
+	SAFE_MOUNT(DIR_C, DIR_C, "none", MS_BIND, NULL);
+	SAFE_MOUNT("none", DIR_C, "none", MS_SHARED, NULL);
+
+	/* DIR_A mounts into DIR_B. DIR_D is propagated */
+	SAFE_MKDIR(DIR_B, 0700);
+	SAFE_MOUNT(DIR_A, DIR_B, "none", MS_BIND, NULL);
+	SAFE_MOUNT("none", DIR_B, "none", MS_SLAVE, NULL);
+
+	SAFE_STATX(AT_FDCWD, DIR_D, 0, STATX_MNT_ID_UNIQUE, &sx);
+	dird_id = sx.stx_mnt_id;
+
+	peer_group_id = read_peer_group();
+}
+
+static void cleanup(void)
+{
+	if (tst_is_mounted(DIR_C))
+		SAFE_UMOUNT(DIR_C);
+
+	if (tst_is_mounted(DIR_B))
+		SAFE_UMOUNT(DIR_B);
+
+	if (tst_is_mounted(DIR_A))
+		SAFE_UMOUNT(DIR_A);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.setup = setup,
+	.cleanup = cleanup,
+	.min_kver = "6.8",
+	.needs_tmpdir = 1,
+	.format_device = 1,
+	.mount_device = 1,
+	.mntpoint = MNTPOINT,
+	.all_filesystems = 1,
+	.skip_filesystems = (const char *const []) {
+		"fuse",
+		NULL
+	},
+	.bufs = (struct tst_buffers []) {
+		{&st_mount, .size = sizeof(struct statmount)},
+		{}
+	}
+};
-- 
2.35.3