[LTP] [PATCH 1/2] splice02: Generate input in C
Cyril Hrubis
chrubis@suse.cz
Fri Apr 9 12:58:59 CEST 2021
Hi!
> changes v1->v2:
> * writing in loop (Cyril), that allowed to drop TST_CHECKPOINT_*()
> * default number of writes is 2x max pipe size
> * fixed problems reported by Cyril (drop redundant close(STDIN_FILENO),
> better phrase error message).
>
> NOTE: I kept verbose output to make behavior easier for reviewers.
> Mainly to see if write size and whole behavior is ok (please do run the
> test). But before merge I guess I should then delete:
> tst_res(TINFO, "splice() wrote %ld, remaining %d", TST_RET, to_write);
>
> I haven't compared file content (Cyril), only checked size.
>
> Kind regards,
> Petr
>
> runtest/smoketest | 2 +-
> runtest/syscalls | 2 +-
> testcases/kernel/syscalls/splice/splice02.c | 102 +++++++++++++++++---
> 3 files changed, 92 insertions(+), 14 deletions(-)
>
> diff --git a/runtest/smoketest b/runtest/smoketest
> index 0c24fc1fa..ec0c088cb 100644
> --- a/runtest/smoketest
> +++ b/runtest/smoketest
> @@ -11,5 +11,5 @@ symlink01 symlink01
> stat04 symlink01 -T stat04
> utime01A symlink01 -T utime01
> rename01A symlink01 -T rename01
> -splice02 seq 1 20 | splice02
> +splice02 splice02 -n 20
> route4-change-dst route-change-dst.sh
> diff --git a/runtest/syscalls b/runtest/syscalls
> index 2d1e7b648..b89c545f0 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -1451,7 +1451,7 @@ socketpair02 socketpair02
> sockioctl01 sockioctl01
>
> splice01 splice01
> -splice02 seq 1 20000 | splice02
> +splice02 splice02
> splice03 splice03
> splice04 splice04
> splice05 splice05
> diff --git a/testcases/kernel/syscalls/splice/splice02.c b/testcases/kernel/syscalls/splice/splice02.c
> index b579667b9..20bf91fb1 100644
> --- a/testcases/kernel/syscalls/splice/splice02.c
> +++ b/testcases/kernel/syscalls/splice/splice02.c
> @@ -1,40 +1,118 @@
> // SPDX-License-Identifier: GPL-2.0-or-later
> /*
> * Copyright (c) Jens Axboe <axboe@kernel.dk>, 2009
> + * Copyright (c) 2021 Petr Vorel <pvorel@suse.cz>
> + */
> +
> +/*\
> + * [DESCRIPTION]
> + * Original reproducer for kernel fix
> + * bf40d3435caf NFS: add support for splice writes
> + * from v2.6.31-rc1.
> + *
> * http://lkml.org/lkml/2009/4/2/55
> + *
> + * [ALGORITHM]
> + * - create pipe
> + * - fork(), child replace stdin with pipe
> + * - parent write to pipe
> + * - child slice from pipe
> + * - check resulted file size
> */
>
> #define _GNU_SOURCE
>
> +#include <fcntl.h>
> #include <stdio.h>
> #include <stdlib.h>
> +#include <sys/stat.h>
> #include <unistd.h>
> -#include <fcntl.h>
>
> #include "tst_test.h"
> #include "lapi/splice.h"
>
> -#define SPLICE_SIZE (64*1024)
> +#define WRITE_SIZE 1024
> +#define TEST_FILENAME "splice02-temp"
> +
> +static char *narg;
> +static int num_writes = -1;
> +static int pipe_fd[2];
> +
> +static void setup(void)
> +{
> + if (tst_parse_int(narg, &num_writes, 1, INT_MAX))
> + tst_brk(TBROK, "invalid number of writes '%s'", narg);
> +}
>
> -static void splice_test(void)
> +static void do_child(void)
> {
> - int fd;
> + int fd, to_write = num_writes;
> + struct stat st;
> +
> + SAFE_CLOSE(pipe_fd[1]);
> + SAFE_DUP2(pipe_fd[0], STDIN_FILENO);
>
> - fd = SAFE_OPEN("splice02-temp", O_WRONLY | O_CREAT | O_TRUNC, 0644);
> + fd = SAFE_OPEN(TEST_FILENAME, O_WRONLY | O_CREAT | O_TRUNC, 0644);
>
> - TEST(splice(STDIN_FILENO, NULL, fd, NULL, SPLICE_SIZE, 0));
> - if (TST_RET < 0) {
> - tst_res(TFAIL, "splice failed - errno = %d : %s",
> - TST_ERR, strerror(TST_ERR));
> - } else {
> - tst_res(TPASS, "splice() system call Passed");
> + while (to_write > 0) {
> + TEST(splice(STDIN_FILENO, NULL, fd, NULL, WRITE_SIZE, 0));
> + tst_res(TINFO, "splice() wrote %ld, remaining %d", TST_RET, to_write);
> + if (TST_RET < 0) {
> + tst_res(TFAIL | TTERRNO, "splice failed");
> + goto cleanup;
> + } else {
> + to_write -= TST_RET;
> + }
> }
Shouldn't we break the cycle here if get 0 from splice()?
If I'm reading the manual right it will return with 0 if the other end
of the pipe gets closed.
You can try to increase to_write by 1 here, I guess that we would end up
in an infinite loop here.
And maybe we can just loop here until splice() returns 0 to make things
simpler.
> + stat(TEST_FILENAME, &st);
> + if (st.st_size != num_writes) {
> + tst_res(TFAIL, "file size is different from expected: %d (%d)",
> + st.st_size, num_writes);
> + return;
> + }
> +
> + tst_res(TPASS, "splice() system call passed");
> +
> +cleanup:
> SAFE_CLOSE(fd);
> + exit(0);
> +}
> +
> +static void run(void)
> +{
> + int i, max_pipe_size;
> +
> + SAFE_PIPE(pipe_fd);
> +
> + if (num_writes == -1) {
Btw we can let the num_writes initialized to 0 and do if (!num_writes)
here instead.
> + max_pipe_size = SAFE_FCNTL(pipe_fd[1], F_GETPIPE_SZ);
> + num_writes = max_pipe_size << 2;
^
This is 4x btw, bit shift by
1 is 2x
> + }
> +
> + if (SAFE_FORK())
> + do_child();
if (!SAFE_FORK()) ?
It's mildly confusing that the parent executes do_child() here, not that
it matters that much though.
> + tst_res(TINFO, "writting %d times", num_writes);
> +
> + for (i = 0; i < num_writes; i++)
> + SAFE_WRITE(1, pipe_fd[1], "x", 1);
> +
> + tst_reap_children();
> +
> + SAFE_CLOSE(pipe_fd[0]);
> + SAFE_CLOSE(pipe_fd[1]);
> }
>
> static struct tst_test test = {
> - .test_all = splice_test,
> + .test_all = run,
> + .setup = setup,
> + .needs_checkpoints = 1,
> .needs_tmpdir = 1,
> + .forks_child = 1,
> .min_kver = "2.6.17",
> + .options = (struct tst_option[]) {
> + {"n:", &narg, "-n x Number of writes (default 2x max pipe size)"},
> + {}
> + },
> };
> --
> 2.30.2
>
--
Cyril Hrubis
chrubis@suse.cz
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