[LTP] [PATCH v4] dio_truncate.c test refactory with LTP API
Cyril Hrubis
chrubis@suse.cz
Fri Nov 19 10:48:52 CET 2021
Hi!
Nearly finished, a few comments below.
> Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
> ---
> testcases/kernel/io/ltp-aiodio/dio_truncate.c | 194 ++++++++----------
> 1 file changed, 85 insertions(+), 109 deletions(-)
>
> diff --git a/testcases/kernel/io/ltp-aiodio/dio_truncate.c b/testcases/kernel/io/ltp-aiodio/dio_truncate.c
> index 27cf01525..28e229d59 100644
> --- a/testcases/kernel/io/ltp-aiodio/dio_truncate.c
> +++ b/testcases/kernel/io/ltp-aiodio/dio_truncate.c
> @@ -1,177 +1,153 @@
> -
> +// SPDX-License-Identifier: GPL-2.0-or-later
> /*
> * Copyright (c) 2004 Daniel McNeil <daniel@osdl.org>
> - * 2004 Open Source Development Lab
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License as published by
> - * the Free Software Foundation; either version 2 of the License, or
> - * (at your option) any later version.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
> - * the GNU General Public License for more details.
> - *
> - * You should have received a copy of the GNU General Public License
> - * along with this program; if not, write to the Free Software
> - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> - *
> - * Module: .c
> + * 2004 Open Source Development Lab
> + * Copyright (C) 2021 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
> */
>
> -/*
> - * Change History:
> +/*\
> + * [Description]
> *
> - * 2/2004 Marty Ridgeway (mridge@us.ibm.com) Changes to adapt to LTP
> + * This test is mixing DIO and truncate operations checking if they can be used
> + * together at the same time. Multiple children are spawned to read a file that
> + * is edited using DIO write/read operations. Algorithm:
> + *
^
Trailing whitespace, please make sure not to add these.
Also I would write the DIO as 'direct I/O' to make things more clear.
> + * - Spawn multiple children which start to read on 'file'
> + * - Parent start to fill and truncate 'file' many times with zero char when
> + * children are reading
> + * - Parent start to fill and truncate a junk file many times with non-zero char
> *
> + * If no issues occures on DIO/truncate operations and the file always contains
> + * non-zero characters, test PASS. Otherwise, test will FAIL.
> */
> +
> #define _GNU_SOURCE
>
> #include <stdlib.h>
> +#include <stdio.h>
> +#include <sys/stat.h>
> #include <sys/types.h>
> -#include <signal.h>
> -#include <errno.h>
> #include <fcntl.h>
> -#include <stdio.h>
> -#include <unistd.h>
> -#include <memory.h>
> -#include <string.h>
> -#include <limits.h>
> +#include "tst_test.h"
>
> -#include "test.h"
> +#define NUM_CHILDREN 16
> +#define FILE_SIZE (64 * 1024)
>
> -#define NUM_CHILDREN 8
> +static int *run_child;
>
> -char *check_zero(unsigned char *buf, int size)
> +static char *check_zero(char *buf, int size)
> {
> - unsigned char *p;
> + char *p;
>
> p = buf;
>
> while (size > 0) {
> if (*buf != 0) {
> - fprintf(stderr,
> - "non zero buffer at buf[%d] => 0x%02x,%02x,%02x,%02x\n",
> - buf - p, (unsigned int)buf[0],
> - size > 1 ? (unsigned int)buf[1] : 0,
> - size > 2 ? (unsigned int)buf[2] : 0,
> - size > 3 ? (unsigned int)buf[3] : 0);
> - fprintf(stderr, "buf %p, p %p\n", buf, p);
> + tst_res(TINFO,
> + "non zero buffer at buf[%lu] => 0x%02x,%02x,%02x,%02x",
> + buf - p, (unsigned int)buf[0],
> + size > 1 ? (unsigned int)buf[1] : 0,
> + size > 2 ? (unsigned int)buf[2] : 0,
> + size > 3 ? (unsigned int)buf[3] : 0);
These parameters would be better aligned with the start of the TINFO
> + tst_res(TINFO, "buf %p, p %p", buf, p);
> return buf;
> }
> buf++;
> size--;
> }
> - return 0; /* all zeros */
> + return 0; /* all zeros */
> }
>
> -int dio_read(char *filename)
> +static void dio_read(const char *filename, size_t bs)
> {
> int fd;
> int r;
> - void *bufptr = NULL;
> + char *bufptr;
>
> - TEST(posix_memalign(&bufptr, 4096, 64 * 1024));
> - if (TEST_RETURN) {
> - tst_resm(TBROK | TRERRNO, "cannot malloc aligned memory");
> - return -1;
> - }
> + bufptr = SAFE_MEMALIGN(getpagesize(), bs);
>
> - while ((fd = open(filename, O_DIRECT | O_RDONLY)) < 0) {
> - }
> - fprintf(stderr, "dio_truncate: child reading file\n");
> - while (1) {
> + while ((fd = open(filename, O_RDONLY | O_DIRECT, 0666)) < 0)
> + usleep(100);
> +
> + tst_res(TINFO, "child reading file");
> + while (*run_child) {
> off_t offset;
> char *bufoff;
>
> /* read the file, checking for zeros */
> - offset = lseek(fd, SEEK_SET, 0);
> + offset = SAFE_LSEEK(fd, SEEK_SET, 0);
> do {
> r = read(fd, bufptr, 64 * 1024);
> if (r > 0) {
> - if ((bufoff = check_zero(bufptr, r))) {
> - fprintf(stderr,
> - "non-zero read at offset %p\n",
> - offset + bufoff);
> - exit(1);
> + bufoff = check_zero(bufptr, r);
> + if (bufoff) {
> + tst_res(TINFO, "non-zero read at offset %p", offset + bufoff);
> + SAFE_CLOSE(fd);
> + return;
> }
> offset += r;
> }
> } while (r > 0);
> }
> - return 0;
> +
> + SAFE_CLOSE(fd);
> +
> + tst_res(TPASS, "zero buffer only after truncate");
> }
>
> -void dio_append(char *filename, int fill)
> +static void dio_append(const char *path, char pattern, size_t bs, size_t bcount)
> {
> int fd;
> - void *bufptr = NULL;
> - int i;
> - int w;
> -
> - fd = open(filename, O_DIRECT | O_WRONLY | O_CREAT, 0666);
> + size_t i;
> + char *bufptr;
>
> - if (fd < 0) {
> - perror("cannot create file");
> - return;
> - }
> + bufptr = SAFE_MEMALIGN(getpagesize(), bs);
> + memset(bufptr, pattern, bs);
>
> - TEST(posix_memalign(&bufptr, 4096, 64 * 1024));
> - if (TEST_RETURN) {
> - tst_resm(TBROK | TRERRNO, "cannot malloc aligned memory");
> - close(fd);
> - return;
> - }
> + fd = SAFE_OPEN(path, O_CREAT | O_WRONLY | O_DIRECT, 0666);
>
> - memset(bufptr, fill, 64 * 1024);
> + for (i = 0; i < bcount; i++)
> + SAFE_WRITE(1, fd, bufptr, bs);
>
> - for (i = 0; i < 1000; i++) {
> - if ((w = write(fd, bufptr, 64 * 1024)) != 64 * 1024) {
> - fprintf(stderr, "write %d returned %d\n", i, w);
> - }
> - }
> - close(fd);
> + SAFE_CLOSE(fd);
This function is called repeatedly, so we should either free the buffer
at the end.
> }
>
> -int main(void)
> +static void run(void)
> {
> - char filename[PATH_MAX];
> + char *filename = "file";
> + int filesize = FILE_SIZE;
> + int num_children = NUM_CHILDREN;
> int pid[NUM_CHILDREN];
> - int num_children = 1;
> + int status;
> int i;
>
> - snprintf(filename, sizeof(filename), "%s/aiodio/file",
> - getenv("TMP") ? getenv("TMP") : "/tmp");
> + run_child = SAFE_MMAP(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
This should be mapped in the test setup() function and unmapped in the
cleanup(). The run() function itself can be executed serveral times with
-i parameter and there is no point to map this over and over.
> + *run_child = 1;
>
> for (i = 0; i < num_children; i++) {
> - if ((pid[i] = fork()) == 0) {
> - /* child */
> - return dio_read(filename);
> - } else if (pid[i] < 0) {
> - /* error */
> - perror("fork error");
> - break;
> - } else {
> - /* Parent */
> - continue;
> + pid[i] = SAFE_FORK();
> + if (pid[i] == 0) {
> + dio_read(filename, filesize);
> + return;
> }
> }
>
> - /*
> - * Parent creates a zero file using DIO.
> - * Truncates it to zero
> - * Create another file with '0xaa'
> - */
> - for (i = 0; i < 100; i++) {
> - dio_append(filename, 0);
> - truncate(filename, 0);
> - dio_append("junkfile", 0xaa);
> - truncate("junkfile", 0);
> - }
> -
> for (i = 0; i < num_children; i++) {
> - kill(pid[i], SIGTERM);
> + dio_append(filename, 0, filesize, 200);
> + SAFE_TRUNCATE(filename, 0);
> + dio_append("junkfile", 0xaa, filesize, 200);
> + SAFE_TRUNCATE("junkfile", 0);
> }
>
> - return 0;
Actually as it is the test does not produce failures at all.
What is missing here is SAFE_WAITPID(-1, &status, WNOHANG); at the end
of the loop that appends and trucantes the file, if we find any child
did exit before we set run_child to 0 we have a failure.
Also I would move the TPASS here as well so that we have.
int fail = 0;
for (...) {
append(foo);
truncate(foo);
append(foo);
truncate(foo);
if (SAFE_WAITPID(-1, &status, WNOHANG)) {
fail = 1;
break;
}
}
if (fail)
tst_res(TFAIL, "Non zero bytes read");
else
tst_res(TPASS, "All bytes read were zeroed");
Or we can do even better, since we have the shared memory set up anyways
we can put a structure with a failure counter in there as well.
struct ipc {
int run_child;
int fails;
} *ipc;
Then the child would increment the counter with atomic operation on a
falure.
if (bufoff) {
tst_atomic_inc(&ipc->fails);
...
}
And the main process would simply do:
for (...) {
append(foo);
truncate(foo);
append(foo);
truncate(foo);
if (SAFE_WAITPID(-1, &status, WNOHANG))
break;
}
*run_child = 0;
for (i = 0; i < num_children; i++)
SAFE_WAITPID(pid[i], &status, 0);
if (ipc->fails)
tst_res(TFAIL, "...");
else
tst_res(TPASS, "...");
> +static struct tst_test test = {
> + .needs_tmpdir = 1,
> + .test_all = run,
> + .forks_child = 1,
> +};
> --
> 2.33.1
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
--
Cyril Hrubis
chrubis@suse.cz
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