[2/2] syscalls/vmsplice: Add NONBLOCK testcase

Add a testcase for vmsplice() with the flag SPLICE_F_NONBLOCK.
And also test that vmsplice() blocks when writing to a full pipe
without the flag specified.

Signed-off-by: Jorik Cronenberg <jcronenberg@suse.de>
---
 testcases/kernel/syscalls/vmsplice/.gitignore |  1 +
 .../kernel/syscalls/vmsplice/vmsplice04.c     | 87 +++++++++++++++++++
 2 files changed, 88 insertions(+)
 create mode 100644 testcases/kernel/syscalls/vmsplice/vmsplice04.c

Hi
> Add a testcase for vmsplice() with the flag SPLICE_F_NONBLOCK.
> And also test that vmsplice() blocks when writing to a full pipe
> without the flag specified.
> 
> Signed-off-by: Jorik Cronenberg <jcronenberg@suse.de>
> ---
>   testcases/kernel/syscalls/vmsplice/.gitignore |  1 +
>   .../kernel/syscalls/vmsplice/vmsplice04.c     | 87 +++++++++++++++++++
>   2 files changed, 88 insertions(+)
>   create mode 100644 testcases/kernel/syscalls/vmsplice/vmsplice04.c
add vmsplice04 into runtest/syscalls
> 
> diff --git a/testcases/kernel/syscalls/vmsplice/.gitignore b/testcases/kernel/syscalls/vmsplice/.gitignore
> index 03922073c..042c32585 100644
> --- a/testcases/kernel/syscalls/vmsplice/.gitignore
> +++ b/testcases/kernel/syscalls/vmsplice/.gitignore
> @@ -1,3 +1,4 @@
>   /vmsplice01
>   /vmsplice02
>   /vmsplice03
> +/vmsplice04
> diff --git a/testcases/kernel/syscalls/vmsplice/vmsplice04.c b/testcases/kernel/syscalls/vmsplice/vmsplice04.c
> new file mode 100644
> index 000000000..c49657d84
> --- /dev/null
> +++ b/testcases/kernel/syscalls/vmsplice/vmsplice04.c
> @@ -0,0 +1,87 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2019 SUSE LLC
> + * Author: Jorik Cronenberg <jcronenberg@suse.de>
> + *
> + * Test vmsplice() to a full pipe with SPLICE_F_NONBLOCK and without
> + * With SPLICE_F_NONBLOCK vmsplice() should return with errno EAGAIN
> + * Without SPLICE_F_NONBLOCK it should block
> + */
> +
> +#define _GNU_SOURCE
> +
> +#include "tst_test.h"
> +#include "lapi/vmsplice.h"
> +#include <stdlib.h>
miss "lapi/fcntl.h". it will compile failed because of undefined 
F_GETPIPE_SZ error on centos6 like my pipe12.c(v1)

https://travis-ci.org/xuyang0410/ltp/jobs/629597516?utm_medium=notification&utm_source=github_status

> +
> +
> +static int pipes[2];
> +static ssize_t pipe_max_size;
> +static char *write_buffer;
> +
> +static void vmsplice_test(void)
> +{
> +	int status;
> +	struct iovec iov;
> +	int pid;
> +
> +	iov.iov_base = write_buffer;
> +	iov.iov_len = pipe_max_size;
> +
> +
> +	TEST(vmsplice(pipes[1], &iov, 1, 0));
> +	if (TST_RET < 0)
> +		tst_brk(TBROK | TTERRNO,
> +		    "Initial vmsplice() to fill pipe failed");
> +
> +	TEST(vmsplice(pipes[1], &iov, 1, SPLICE_F_NONBLOCK));
> +	if (TST_RET < 0 && TST_ERR == EAGAIN)
> +		tst_res(TPASS | TTERRNO, "vmsplice failed as expected");
I think we should add more info. such as "vmsplice failed EAGAIN to full 
pipe with SPLICE_F_NONBLOCK mode"
> +	else if (TST_RET < 0)
> +		tst_res(TFAIL | TTERRNO,
> +		    "vmsplice failed with unexpected errno");
here as well
> +	else
> +		tst_res(TFAIL, "vmsplice wrote to a full pipe");
here as well
> +
> +	pid = SAFE_FORK();
> +	if (!pid) {
> +		TEST(vmsplice(pipes[1], &iov, 1, 0));
> +		if (TST_RET < 0)
> +			tst_res(TFAIL | TTERRNO, "vmsplice() failed");
> +		else
> +			tst_res(TFAIL, "vmsplice() wrote to a full pipe");
> +		exit(0);
> +	} else {
> +		if (TST_PROCESS_STATE_WAIT2(pid, 'S', 1000) < 0)
> +			return;
> +		else
> +			tst_res(TPASS, "vmsplice() blocked");
here as well (without SPLICE_F_NONBLOCK mode)
> +		SAFE_KILL(pid, SIGKILL);
> +		SAFE_WAIT(&status);
> +	}
> +
> +}
> +static void cleanup(void)
> +{
> +	if (pipes[1] > 0)
> +		SAFE_CLOSE(pipes[1]);
> +	if (pipes[0] > 0)
> +		SAFE_CLOSE(pipes[0]);
> +	if (write_buffer)
> +		free(write_buffer);
> +}
> +static void setup(void)
> +{
> +	SAFE_PIPE(pipes);
> +
> +	pipe_max_size = SAFE_FCNTL(pipes[1], F_GETPIPE_SZ);
> +	write_buffer = SAFE_MALLOC(pipe_max_size);
Can we use guarded buffer for iov in setup?
https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines#2231-guarded-buffers

other than, this patch looks good to me.
> +}
> +
> +static struct tst_test test = {
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.test_all = vmsplice_test,
> +	.min_kver = "2.6.17",
> +	.forks_child = 1,
> +};
>