[LTP] [PATCH v3 3/3] syscalls/pipe2_03: Add new test for pipe2 O_DIRECT flag
Yang Xu
xuyang2018.jy@cn.fujitsu.com
Tue Apr 21 12:21:22 CEST 2020
Hi Li
>
>
> On Thu, Apr 16, 2020 at 3:29 PM Yang Xu <xuyang2018.jy@cn.fujitsu.com
> <mailto:xuyang2018.jy@cn.fujitsu.com>> wrote:
>
> Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com
> <mailto:xuyang2018.jy@cn.fujitsu.com>>
> ---
> runtest/syscalls | 1 +
> testcases/kernel/syscalls/pipe2/.gitignore | 1 +
> testcases/kernel/syscalls/pipe2/pipe2_03.c | 157 +++++++++++++++++++++
> 3 files changed, 159 insertions(+)
> create mode 100644 testcases/kernel/syscalls/pipe2/pipe2_03.c
>
> diff --git a/runtest/syscalls b/runtest/syscalls
> index 44254d7da..4d8ebc5a3 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -912,6 +912,7 @@ pipe13 pipe13
>
> pipe2_01 pipe2_01
> pipe2_02 pipe2_02
> +pipe2_03 pipe2_03
>
> pivot_root01 pivot_root01
>
> diff --git a/testcases/kernel/syscalls/pipe2/.gitignore
> b/testcases/kernel/syscalls/pipe2/.gitignore
> index 786222de2..4cc5acaf1 100644
> --- a/testcases/kernel/syscalls/pipe2/.gitignore
> +++ b/testcases/kernel/syscalls/pipe2/.gitignore
> @@ -1,3 +1,4 @@
> /pipe2_01
> /pipe2_02
> /pipe2_02_child
> +/pipe2_03
> diff --git a/testcases/kernel/syscalls/pipe2/pipe2_03.c
> b/testcases/kernel/syscalls/pipe2/pipe2_03.c
> new file mode 100644
> index 000000000..0b5d37dd0
> --- /dev/null
> +++ b/testcases/kernel/syscalls/pipe2/pipe2_03.c
> @@ -0,0 +1,157 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2020 FUJITSU LIMITED. All rights reserved.
> + * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com
> <mailto:xuyang2018.jy@cn.fujitsu.com>>
> + *
> + * This case is designed to test the basic functionality about the
> + * O_DIRECT flag of pipe2.
> + *
> + * It includes three sub tests.
> + * 1) Each write(2) to the pipe is dealt with as a separate packet, and
> + * read(2)s from the pipe will read one packet at a time.
> + * 2) Writes of greater than PIPE_BUF bytes (see pipe(7)) will be split
> + * into multiple packet.
> + * 3)If a read(2) specifies a buffer size that is smaller than the next
> + * packet, then the requested number of bytes are read, and the excess
> + * bytes in the packet are discarded.
> + */
> +#define _GNU_SOURCE
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <stdlib.h>
> +#include <linux/limits.h>
> +#include "lapi/fcntl.h"
> +#include "tst_test.h"
> +
> +static int fds[2], packet_num, pipe_size;
> +static char *wrbuf;
> +static char *rdbuf;
> +static void check_peer_rw(void);
> +static void check_split(void);
> +static void check_discard(void);
> +
> +static void (*test_func[])(void) = {check_peer_rw, check_split,
> check_discard};
> +
> +static void check_peer_rw(void)
> +{
> + int i, pid;
> +
> + SAFE_PIPE2(fds, O_DIRECT | O_NONBLOCK);
> + for (i = 0; i < packet_num; i++)
> + SAFE_WRITE(1, fds[1], "x", 1);
> +
> + TEST(write(fds[1], "x", 1));
> + if (TST_RET != -1) {
> + tst_res(TFAIL, "write succeeded unexpectedly");
> + } else {
> + if (TST_ERR == EAGAIN)
> + tst_res(TPASS, "Each write(2) uses a
> separate packet");
> + else
> + tst_res(TFAIL | TTERRNO, "write failed,
> expected EAGAIN but got");
> + }
> + pid = SAFE_FORK();
> + if (!pid) {
> + memset(rdbuf, 0, pipe_size);
> + for (i = 0; i < packet_num; i++) {
> + TEST(SAFE_READ(0, fds[0], rdbuf, pipe_size));
> + if (TST_RET != 1)
> + tst_res(TFAIL,
> + "Each read(2) doesn't read a
> separate packet, return %ld", TST_RET);
> + }
> + tst_res(TPASS, "Each read(2) reads a separate packet");
>
>
> I would add _exit(0); at the end of the child.
> + _exit(0);
>
> + }
>
>
> And move the tst_reap_children() from the main process to here.
>
> + tst_reap_children();
> + SAFE_CLOSE(fds[0]);
> + SAFE_CLOSE(fds[1]);
>
> +}
> +
> +static void check_split(void)
> +{
> + int i, pid;
> +
> + SAFE_PIPE2(fds, O_DIRECT);
> + SAFE_WRITE(1, fds[1], wrbuf, PIPE_BUF * 2);
> +
> + pid = SAFE_FORK();
> + if (!pid) {
> + memset(rdbuf, 0, pipe_size);
> + for (i = 0; i < 2; i++) {
> + TEST(SAFE_READ(0, fds[0], rdbuf, pipe_size));
> + if (TST_RET != PIPE_BUF)
> + tst_res(TFAIL,
> + "write(higner than PIPE_BUF)
> split into multiple packet, return %ld", TST_RET);
> + }
> + tst_res(TPASS, "write(higner than PIPE_BUF) split
> into multiple packet");
>
> + _exit(0);
>
> + }
>
> + tst_reap_children();
> + SAFE_CLOSE(fds[0]);
> + SAFE_CLOSE(fds[1]);
>
> +}
> +
> +static void check_discard(void)
> +{
> + int pid;
> + char tmp_buf[20];
> + char tmp_secondbuf[20];
> +
> + SAFE_PIPE2(fds, O_DIRECT);
> + SAFE_WRITE(1, fds[1], wrbuf, PIPE_BUF);
> + SAFE_WRITE(1, fds[1], "1", 1);
> +
> + pid = SAFE_FORK();
> + if (!pid) {
> + TEST(SAFE_READ(0, fds[0], tmp_buf, 20));
> + if (TST_RET != 20)
> + tst_res(TFAIL,
> + "the excess bytes in the packet
> isn't discarded by read, return %ld", TST_RET);
> + TEST(SAFE_READ(0, fds[0], tmp_secondbuf, 20));
> + if (TST_RET == 1) {
> + if (!strcmp(tmp_secondbuf, "1"))
> + tst_res(TPASS,
> + "the excess bytes in the
> packet is discarded by read, only read 1");
> + else
> + tst_res(TFAIL,
> + "the excess bytes in the
> packet is discarded by read, expect 1 got %s", tmp_secondbuf);
> + }
>
> + _exit(0);
>
> + }
>
> + tst_reap_children();
> + SAFE_CLOSE(fds[0]);
> + SAFE_CLOSE(fds[1]);
>
> +}
> +
> +static void verify_pipe2(unsigned int n)
> +{
> + int pid;
> +
> + pid = SAFE_FORK();
>
>
> Why we need fork() here? I don't see any necessary reason for twice fork
> in the main process.Yes, it only needs one fork. At the beginning, I think we should do
actual test in child process( I remember having such rule) especially
when there are multiple subtests. So I fork twice to make sure all sub
test in child or grandchild process.
>
> + if (pid == 0) {
> + (*test_func[n])();
>
> + tst_reap_children();
> + SAFE_CLOSE(fds[0]);
> + SAFE_CLOSE(fds[1]);
>
>
> I tend to move the cloese(fd) to the test process to nearby pipe2().
> Otherwise, it causes an unclear error like:
>
> # ./pipe2_03
> tst_test.c:1246: INFO: Timeout per run is 0h 05m 00s
> pipe2_03.c:48: PASS: Each write(2) uses a separate packet
> pipe2_03.c:61: PASS: Each read(2) reads a separate packet
> pipe2_03.c:81: PASS: write(higner than PIPE_BUF) split into multiple packet
> pipe2_03.c:108: FAIL: the excess bytes in the packet is discarded by
> read, expect 1 got 1%A
Even I use one fork and exit(0), I don't meet this problem. Or, I miss
something?
--- a/testcases/kernel/syscalls/pipe2/pipe2_03.c
+++ b/testcases/kernel/syscalls/pipe2/pipe2_03.c
@@ -59,6 +59,7 @@ static void check_peer_rw(void)
"Each read(2) doesn't read a
separate packet, return %ld", TST_RET);
}
tst_res(TPASS, "Each read(2) reads a separate packet");
+ _exit(0);
}
}
@@ -79,6 +80,7 @@ static void check_split(void)
"write(higner than PIPE_BUF)
split into multiple packet, return %ld", TST_RET);
}
tst_res(TPASS, "write(higner than PIPE_BUF) split into
multiple packet");
+ _exit(0);
}
}
@@ -107,21 +109,17 @@ static void check_discard(void)
tst_res(TFAIL,
"the excess bytes in the packet
is discarded by read, expect 1 got %s", tmp_secondbuf);
}
+ _exit(0);
}
}
static void verify_pipe2(unsigned int n)
{
- int pid;
-
- pid = SAFE_FORK();
- if (pid == 0) {
- (*test_func[n])();
- tst_reap_children();
- SAFE_CLOSE(fds[0]);
- SAFE_CLOSE(fds[1]);
- }
+ (*test_func[n])();
+ SAFE_CLOSE(fds[0]);
+ SAFE_CLOSE(fds[1]);
tst_reap_children();
+
}
>
> + }
> + tst_reap_children();
> +}
> +
> +static void setup(void)
> +{
> + SAFE_PIPE2(fds, O_DIRECT);
> + pipe_size = SAFE_FCNTL(fds[1], F_GETPIPE_SZ);
> + wrbuf = SAFE_MALLOC(PIPE_BUF * 2);
> + rdbuf = SAFE_MALLOC(pipe_size);
> + memset(wrbuf, 'x', PIPE_BUF * 2);
> + packet_num = pipe_size / PIPE_BUF;
> + SAFE_CLOSE(fds[0]);
> + SAFE_CLOSE(fds[1]);
> +}
> +
> +static void cleanup(void)
> +{
> + if (fds[0] > 0)
> + SAFE_CLOSE(fds[0]);
> + if (fds[1] > 0)
> + SAFE_CLOSE(fds[1]);
> + if (wrbuf)
> + free(wrbuf);
> + if (rdbuf)
> + free(rdbuf);
> +}
> +
> +static struct tst_test test = {
> + .setup = setup,
> + .cleanup = cleanup,
> + .forks_child = 1,
> + .test = verify_pipe2,
> + .tcnt = ARRAY_SIZE(test_func),
> +};
> --
> 2.23.0
>
>
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>
>
>
> --
> Regards,
> Li Wang
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