Add a test to verify that detached mounts behave correctly. Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> --- .../selftests/mount_setattr/mount_setattr_test.c | 40 ++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/tools/testing/selftests/mount_setattr/mount_setattr_test.c b/tools/testing/selftests/mount_setattr/mount_setattr_test.c index 885d98f2d889..0641d2e22e02 100644 --- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c +++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c @@ -1789,4 +1789,44 @@ TEST_F(mount_setattr, open_tree_detached_fail3) ASSERT_EQ(errno, EINVAL); } +TEST_F(mount_setattr, mount_detached_mount_on_detached_mount_then_close) +{ + int fd_tree_base = -EBADF, fd_tree_subdir = -EBADF; + struct statx stx; + + fd_tree_base = sys_open_tree(-EBADF, "/mnt", + AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW | + OPEN_TREE_CLOEXEC | OPEN_TREE_CLONE); + ASSERT_GE(fd_tree_base, 0); + /* + * /mnt testing tmpfs + */ + ASSERT_EQ(statx(fd_tree_base, "A", 0, 0, &stx), 0); + ASSERT_FALSE(stx.stx_attributes & STATX_ATTR_MOUNT_ROOT); + + fd_tree_subdir = sys_open_tree(fd_tree_base, "", + AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW | + AT_EMPTY_PATH | OPEN_TREE_CLOEXEC | + OPEN_TREE_CLONE); + ASSERT_GE(fd_tree_subdir, 0); + /* + * /mnt testing tmpfs + */ + ASSERT_EQ(statx(fd_tree_subdir, "A", 0, 0, &stx), 0); + ASSERT_FALSE(stx.stx_attributes & STATX_ATTR_MOUNT_ROOT); + + /* + * /mnt testing tmpfs + * `-/mnt testing tmpfs + */ + ASSERT_EQ(move_mount(fd_tree_subdir, "", fd_tree_base, "", MOVE_MOUNT_F_EMPTY_PATH | MOVE_MOUNT_T_EMPTY_PATH), 0); + ASSERT_EQ(statx(fd_tree_subdir, "", AT_EMPTY_PATH, 0, &stx), 0); + ASSERT_TRUE(stx.stx_attributes & STATX_ATTR_MOUNT_ROOT); + + ASSERT_NE(move_mount(fd_tree_subdir, "", fd_tree_base, "", MOVE_MOUNT_F_EMPTY_PATH | MOVE_MOUNT_T_EMPTY_PATH), 0); + + EXPECT_EQ(close(fd_tree_base), 0); + EXPECT_EQ(close(fd_tree_subdir), 0); +} + TEST_HARNESS_MAIN -- 2.47.2