From 124dd335568bf4cd2a1001c2f8fe5cc5794c93a8 Mon Sep 17 00:00:00 2001
From: Dmitry Monakhov <dmonakhov@openvz.org>
Date: Thu, 9 Oct 2014 15:01:09 +0400
Subject: [PATCH] add aio/dio regression test race between write and fcntl V2
Original report: https://lkml.org/lkml/2014/10/8/545
perform AIO-DIO and fcntl(F_SETFL) concurently
Unaligned AIO likely result in synchronization which makes racewindow wider.
changes from v1->v2
- Properly reuse aio context
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
---
src/aio-dio-regress/aio-dio-fcntl-race.c | 148 ++++++++++++++++++++++++++++++
tests/generic/326 | 51 ++++++++++
tests/generic/326.out | 2 +
tests/generic/group | 1 +
4 files changed, 202 insertions(+), 0 deletions(-)
create mode 100644 src/aio-dio-regress/aio-dio-fcntl-race.c
create mode 100755 tests/generic/326
create mode 100644 tests/generic/326.out
new file mode 100644
@@ -0,0 +1,148 @@
+/*
+ * Perform aio writes to file and toggle O_DIRECT flag concurrently
+ * this may trigger race between file->f_flags read and modification
+ * unuligned aio allow to makes race window wider.
+ * Regression test for https://lkml.org/lkml/2014/10/8/545
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights reserved.
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <libaio.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#define BUF_SIZE 512
+#define LOOP_SECONDS 10
+
+
+static int do_aio_loop(int fd, void *buf)
+{
+ int err, ret;
+ struct io_context *ctx = NULL;
+ struct io_event ev;
+ struct iocb iocb, *iocbs[] = { &iocb };
+ struct timeval start, now, delta = { 0, 0 };
+
+ ret = 0;
+ err = io_setup(1, &ctx);
+ if (err) {
+ fprintf(stderr, "error %s during %s\n",
+ strerror(-err), "io_setup" );
+ return 1;
+ }
+ while (1) {
+ io_prep_pwrite(&iocb, fd, buf, BUF_SIZE, BUF_SIZE);
+ err = io_submit(ctx, 1, iocbs);
+ if (err != 1) {
+ fprintf(stderr, "error %s during %s\n",
+ strerror(-err),
+ "io_submit");
+ ret = 1;
+ break;
+ }
+ err = io_getevents(ctx, 1, 1, &ev, NULL);
+ if (err != 1) {
+ fprintf(stderr, "error %s during %s\n",
+ strerror(-err),
+ "io_getevents");
+ ret = 1;
+ break;
+ }
+ gettimeofday(&now, NULL);
+ timersub(&now, &start, &delta);
+ if (delta.tv_sec >= LOOP_SECONDS)
+ break;
+ }
+ io_destroy(ctx);
+ return ret;
+}
+
+int main(int argc, char **argv)
+{
+ int flags, fd;
+ int pid1, pid2 = 0;
+ int ret1, ret = 0;
+
+ if (argc != 2){
+ printf("Usage %s fname\n", argv[0]);
+ return 1;
+ }
+ fd = open(argv[1], O_CREAT | O_TRUNC | O_RDWR, 0600);
+ if (fd < 0)
+ return 1;
+
+ pid1 = fork();
+ if (pid1 < 0)
+ return 1;
+
+ if (pid1 == 0) {
+ struct timeval start, now, delta = { 0, 0 };
+
+ gettimeofday(&start, NULL);
+
+ /* child: toggle O_DIRECT*/
+ flags = fcntl(fd, F_GETFL);
+ while (1) {
+ ret = fcntl(fd, F_SETFL, flags | O_DIRECT);
+ if (ret)
+ return ret;
+ ret = fcntl(fd, F_SETFL, flags);
+ if (ret)
+ return ret;
+
+ gettimeofday(&now, NULL);
+ timersub(&now, &start, &delta);
+ if (delta.tv_sec >= LOOP_SECONDS)
+ break;
+ }
+ } else {
+ /* parent: AIO */
+ void *buf;
+ posix_memalign(&buf, BUF_SIZE, BUF_SIZE);
+ /* Two tasks which performs unaligned aio will be serialized
+ which maks race window wider */
+ pid2 = fork();
+ if (pid2 < 0)
+ goto out;
+ else if (pid2 > 0)
+ printf("All tasks are spawned\n");
+
+ ret = do_aio_loop(fd, buf);
+ }
+out:
+ /* Parent wait for all others */
+ if (pid2 > 0){
+ waitpid(pid1, &ret1, 0);
+ if (!ret)
+ ret = ret1;
+ waitpid(pid2, &ret1, 0);
+ } else {
+ waitpid(pid1, &ret1, 0);
+ }
+ if (!ret)
+ ret = ret1;
+
+ return ret;
+}
new file mode 100755
@@ -0,0 +1,51 @@
+#! /bin/bash
+# FS QA Test No. 326
+#
+# Run aio-dio-fcntl-race - test aio write race with O_DIRECT toggle
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2009 Dmitry Monakhov. All Rights Reserved.
+#
+# 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.
+#
+# This program is distributed in the hope that it would 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 the Free Software Foundation,
+# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1 # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+ cd /
+ rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+
+_supported_fs generic
+_supported_os Linux
+_require_test
+
+_run_aiodio aio-dio-fcntl-race
+
+exit $status
new file mode 100644
@@ -0,0 +1,2 @@
+QA output created by 326
+All tasks are spawned
@@ -151,3 +151,4 @@
323 auto aio stress
324 auto fsr quick
325 auto quick data log
+326 auto quick aio rw stress
--
1.7.1