[V5,10/10] syscalls/open_tree: New tests

diff --git a/runtest/syscalls b/runtest/syscalls
index ce27f835c42e..cf4b55e08262 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -844,6 +844,9 @@  openat01 openat01
 openat02 openat02
 openat03 openat03
 
+open_tree01 open_tree01
+open_tree02 open_tree02
+
 mincore01 mincore01
 mincore02 mincore02
 
diff --git a/testcases/kernel/syscalls/open_tree/.gitignore b/testcases/kernel/syscalls/open_tree/.gitignore
new file mode 100644
index 000000000000..2f732b44518e
--- /dev/null
+++ b/testcases/kernel/syscalls/open_tree/.gitignore
@@ -0,0 +1,2 @@ 
+/open_tree01
+/open_tree02
diff --git a/testcases/kernel/syscalls/open_tree/Makefile b/testcases/kernel/syscalls/open_tree/Makefile
new file mode 100644
index 000000000000..5ea7d67db123
--- /dev/null
+++ b/testcases/kernel/syscalls/open_tree/Makefile
@@ -0,0 +1,6 @@ 
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+top_srcdir		?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/syscalls/open_tree/open_tree01.c b/testcases/kernel/syscalls/open_tree/open_tree01.c
new file mode 100644
index 000000000000..b83dbab9df34
--- /dev/null
+++ b/testcases/kernel/syscalls/open_tree/open_tree01.c
@@ -0,0 +1,108 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020 Viresh Kumar <viresh.kumar@linaro.org>
+ *
+ * Basic open_tree() test.
+ */
+#include "tst_test.h"
+#include "lapi/fsmount.h"
+
+#define MNTPOINT	"mntpoint"
+#define OT_MNTPOINT	"ot_mntpoint"
+
+#define TCASE_ENTRY(_flags)	{.name = "Flag " #_flags, .flags = _flags}
+
+static struct tcase {
+	char *name;
+	unsigned int flags;
+} tcases[] = {
+	TCASE_ENTRY(OPEN_TREE_CLONE),
+	TCASE_ENTRY(OPEN_TREE_CLOEXEC)
+};
+
+static void setup(void)
+{
+	fsopen_supported_by_kernel();
+	SAFE_MKDIR(OT_MNTPOINT, 0777);
+}
+
+static void run(unsigned int n)
+{
+	struct tcase *tc = &tcases[n];
+	int fd, fsmfd, otfd;
+
+	TEST(fd = fsopen(tst_device->fs_type, 0));
+	if (fd == -1) {
+		tst_res(TFAIL | TERRNO, "fsopen() failed");
+		return;
+	}
+
+	TEST(fsconfig(fd, FSCONFIG_SET_STRING, "source", tst_device->dev, 0));
+	if (TST_RET == -1) {
+		SAFE_CLOSE(fd);
+		tst_res(TFAIL | TERRNO, "fsconfig() failed");
+		return;
+	}
+
+	TEST(fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0));
+	if (TST_RET == -1) {
+		SAFE_CLOSE(fd);
+		tst_res(TFAIL | TERRNO, "fsconfig() failed");
+		return;
+	}
+
+	TEST(fsmfd = fsmount(fd, 0, 0));
+	SAFE_CLOSE(fd);
+
+	if (fsmfd == -1) {
+		tst_res(TFAIL | TERRNO, "fsmount() failed");
+		return;
+	}
+
+	TEST(move_mount(fsmfd, "", AT_FDCWD, MNTPOINT,
+			MOVE_MOUNT_F_EMPTY_PATH));
+	SAFE_CLOSE(fsmfd);
+
+	if (TST_RET == -1) {
+		tst_res(TFAIL | TERRNO, "move_mount() failed");
+		return;
+	}
+
+	if (!tst_is_mounted(MNTPOINT)) {
+		tst_res(TFAIL | TERRNO, "device not mounted");
+		goto out;
+	}
+
+	TEST(otfd = open_tree(AT_FDCWD, MNTPOINT, tc->flags | OPEN_TREE_CLONE));
+	if (otfd == -1) {
+		tst_res(TFAIL | TERRNO, "open_tree() failed");
+		goto out;
+	}
+
+	TEST(move_mount(otfd, "", AT_FDCWD, OT_MNTPOINT,
+			MOVE_MOUNT_F_EMPTY_PATH));
+	SAFE_CLOSE(otfd);
+
+	if (TST_RET == -1) {
+		tst_res(TFAIL | TERRNO, "move_mount() failed");
+		goto out;
+	}
+
+	if (tst_is_mounted(OT_MNTPOINT))
+		tst_res(TPASS, "%s: open_tree() passed", tc->name);
+
+	SAFE_UMOUNT(OT_MNTPOINT);
+out:
+	SAFE_UMOUNT(MNTPOINT);
+}
+
+static struct tst_test test = {
+	.tcnt = ARRAY_SIZE(tcases),
+	.test = run,
+	.setup = setup,
+	.needs_root = 1,
+	.format_device = 1,
+	.mntpoint = MNTPOINT,
+	.all_filesystems = 1,
+	.dev_fs_flags = TST_FS_SKIP_FUSE,
+};
diff --git a/testcases/kernel/syscalls/open_tree/open_tree02.c b/testcases/kernel/syscalls/open_tree/open_tree02.c
new file mode 100644
index 000000000000..a7e3641d9537
--- /dev/null
+++ b/testcases/kernel/syscalls/open_tree/open_tree02.c
@@ -0,0 +1,105 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020 Viresh Kumar <viresh.kumar@linaro.org>
+ *
+ * Basic open_tree() failure tests.
+ */
+#include "tst_test.h"
+#include "lapi/fsmount.h"
+
+#define MNTPOINT	"mntpoint"
+
+static struct tcase {
+	char *name;
+	int dirfd;
+	const char *pathname;
+	unsigned int flags;
+	int exp_errno;
+} tcases[] = {
+	{"invalid-fd", -1, MNTPOINT, OPEN_TREE_CLONE, EBADF},
+	{"invalid-path", AT_FDCWD, "invalid", OPEN_TREE_CLONE, ENOENT},
+	{"invalid-flags", AT_FDCWD, MNTPOINT, 0xFFFFFFFF, EINVAL},
+};
+
+static int ismounted;
+
+static void cleanup(void)
+{
+	if (ismounted)
+		SAFE_UMOUNT(MNTPOINT);
+}
+
+static void setup(void)
+{
+	int fd, fsmfd;
+
+	fsopen_supported_by_kernel();
+
+	TEST(fd = fsopen(tst_device->fs_type, 0));
+	if (fd == -1)
+		tst_brk(TBROK | TERRNO, "fsopen() failed");
+
+	TEST(fsconfig(fd, FSCONFIG_SET_STRING, "source", tst_device->dev, 0));
+	if (TST_RET == -1) {
+		SAFE_CLOSE(fd);
+		tst_brk(TBROK | TERRNO, "fsconfig() failed");
+	}
+
+	TEST(fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0));
+	if (TST_RET == -1) {
+		SAFE_CLOSE(fd);
+		tst_brk(TBROK | TERRNO, "fsconfig() failed");
+	}
+
+	TEST(fsmfd = fsmount(fd, 0, 0));
+	SAFE_CLOSE(fd);
+
+	if (fsmfd == -1)
+		tst_brk(TBROK | TERRNO, "fsmount() failed");
+
+	TEST(move_mount(fsmfd, "", AT_FDCWD, MNTPOINT,
+			MOVE_MOUNT_F_EMPTY_PATH));
+	SAFE_CLOSE(fsmfd);
+
+	if (TST_RET == -1)
+		tst_brk(TBROK | TERRNO, "move_mount() failed");
+
+	ismounted = 1;
+
+	if (!tst_is_mounted(MNTPOINT))
+		tst_brk(TBROK | TERRNO, "device not mounted");
+}
+
+static void run(unsigned int n)
+{
+	struct tcase *tc = &tcases[n];
+
+	TEST(open_tree(tc->dirfd, tc->pathname, tc->flags));
+	if (TST_RET != -1) {
+		SAFE_CLOSE(TST_RET);
+		tst_res(TFAIL, "%s: open_tree() succeeded unexpectedly (index: %d)",
+			tc->name, n);
+		return;
+	}
+
+	if (tc->exp_errno != TST_ERR) {
+		tst_res(TFAIL | TTERRNO, "%s: open_tree() should fail with %s",
+			tc->name, tst_strerrno(tc->exp_errno));
+		return;
+	}
+
+	tst_res(TPASS | TTERRNO, "%s: open_tree() failed as expected",
+		tc->name);
+}
+
+static struct tst_test test = {
+	.tcnt = ARRAY_SIZE(tcases),
+	.test = run,
+	.setup = setup,
+	.cleanup = cleanup,
+	.needs_root = 1,
+	.format_device = 1,
+	.mntpoint = MNTPOINT,
+	.all_filesystems = 1,
+	.dev_fs_flags = TST_FS_SKIP_FUSE,
+};