Add failing test

Signed-off-by: Shaan Nobee <sniper111@gmail.com>

configure.ac

@@ -363,6 +363,7 @@ AC_CONFIG_FILES([
 	tests/zfs-tests/tests/functional/no_space/Makefile
 	tests/zfs-tests/tests/functional/nopwrite/Makefile
 	tests/zfs-tests/tests/functional/online_offline/Makefile
+	tests/zfs-tests/tests/functional/page_writeback/Makefile
 	tests/zfs-tests/tests/functional/pam/Makefile
 	tests/zfs-tests/tests/functional/pool_checkpoint/Makefile
 	tests/zfs-tests/tests/functional/pool_names/Makefile

tests/runfiles/linux.run

@@ -124,6 +124,10 @@ tags = ['functional', 'mmp']
 tests = ['umount_unlinked_drain']
 tags = ['functional', 'mount']
 
+[tests/functional/page_writeback:Linux]
+tests = ['run_msync_test']
+tags = ['functional', 'page_writeback']
+
 [tests/functional/pam:Linux]
 tests = ['pam_basic', 'pam_nounmount']
 tags = ['functional', 'pam']

tests/zfs-tests/tests/functional/Makefile.am

@@ -88,5 +88,6 @@ SUBDIRS = \
 
 if BUILD_LINUX
 SUBDIRS += \
+	page_writeback \
 	tmpfile
 endif

tests/zfs-tests/tests/functional/page_writeback/.gitignore

@@ -0,0 +1,2 @@
+msync_test
+msync_file

tests/zfs-tests/tests/functional/page_writeback/Makefile.am

@@ -0,0 +1,14 @@
+include $(top_srcdir)/config/Rules.am
+
+pkgdatadir = $(datadir)/@PACKAGE@/zfs-tests/tests/functional/page_writeback
+
+dist_pkgdata_SCRIPTS = \
+	setup.ksh \
+	cleanup.ksh \
+	run_msync_test.ksh
+
+pkgexecdir = $(datadir)/@PACKAGE@/zfs-tests/tests/functional/page_writeback
+
+pkgexec_PROGRAMS = msync_test
+msync_test_SOURCES = msync_test.c
+

tests/zfs-tests/tests/functional/page_writeback/cleanup.ksh

@@ -0,0 +1,50 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+#
+# Copyright (c) 2013, 2016 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+# Revert the settings to some sensible defaults if something went wrong
+# and we were not able to revert back to the original values. (e.g if the
+# test had failed or the previous test run was interrupted)
+
+if [ $(cat /proc/sys/vm/dirty_expire_centisecs) -eq 1 ]; then
+    sudo /bin/sh -c "echo 3000 > /proc/sys/vm/dirty_expire_centisecs"
+fi
+
+if [ $(cat /proc/sys/vm/dirty_background_ratio) -eq 0 ]; then
+    sudo /bin/sh -c "echo 10 > /proc/sys/vm/dirty_background_ratio"
+fi
+
+if [ $(cat /proc/sys/vm/dirty_writeback_centisecs) -eq 1 ]; then
+    sudo /bin/sh -c "echo 500 > /proc/sys/vm/dirty_writeback_centisecs"
+fi
+
+default_cleanup

tests/zfs-tests/tests/functional/page_writeback/msync_test.c

@@ -0,0 +1,128 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <time.h>
+
+#define RUN_TIME_MINS 2
+
+void cleanup(char *file);
+
+void
+cleanup(char *file)
+{
+	remove(file);
+}
+
+int
+main(int argc, char *argv[])
+{
+	char *testdir = getenv("TESTDIR");
+	if (!testdir)
+	{
+		fprintf(stderr, "environment variable TESTDIR not set\n");
+		exit(1);
+	}
+
+	char filepath[512];
+	filepath[0] = '\0';
+	char *file = &filepath[0];
+
+	strcat(file, testdir);
+	strcat(file,"/msync_file");
+
+	const int LEN = 8;
+	cleanup(file);
+
+	int fd = open(file, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+
+	if (ftruncate(fd, LEN) != 0)
+	{
+		fprintf(stderr, "ftruncate failed\n");
+		cleanup(file);
+		return 1;
+	}
+
+	void *ptr = mmap(NULL, LEN, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+
+	if (ptr == MAP_FAILED)
+	{
+		fprintf(stderr, "mmap failed!\n");
+		cleanup(file);
+		return 1;
+	}
+
+	struct timeval tstart;
+	gettimeofday(&tstart, NULL);
+
+	long long x = 0LL;
+
+	for (;;)
+	{
+		*((long long*)ptr) = x;
+		x++;
+
+		struct timeval t1, t2;
+		gettimeofday(&t1, NULL);
+		if (msync(ptr, LEN, MS_SYNC|MS_INVALIDATE) != 0)
+		{
+			fprintf(stderr, "msync failed!\n");
+			cleanup(file);
+			return 1;
+		}
+
+		gettimeofday(&t2, NULL);
+
+		double elapsed = (t2.tv_sec - t1.tv_sec) * 1000.0;
+		elapsed += ((t2.tv_usec - t1.tv_usec) / 1000.0);
+		if (elapsed > 1000.0)
+		{
+			fprintf(stderr, "slow msync: %f ms\n", elapsed);
+			munmap(ptr, LEN);
+			cleanup(file);
+			return 1;
+		}
+
+		double elapsed_start = (t2.tv_sec - tstart.tv_sec) * 1000.0;
+		elapsed_start += ((t2.tv_usec - tstart.tv_usec) / 1000.0);
+		if (elapsed_start > (RUN_TIME_MINS) * 60 * 1000)
+		{
+			break;
+		}
+	}
+
+	int ret = munmap(ptr, LEN);
+	if (ret == -1)
+	{
+		fprintf(stderr, "munmap failed!\n");
+		cleanup(file);
+		return 1;
+	}
+
+	cleanup(file);
+	return 0;
+}

tests/zfs-tests/tests/functional/page_writeback/run_msync_test.ksh

@@ -0,0 +1,43 @@
+#!/bin/ksh -p
+
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2015, 2016 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# Description:
+# Run the tests for msync.
+#
+
+if is_linux; then
+    log_assert "Run the tests for msync"
+
+    saved_vm_dirty_expire_centisecs=$(cat /proc/sys/vm/dirty_expire_centisecs)
+    saved_vm_dirty_background_ratio=$(cat /proc/sys/vm/dirty_background_ratio)
+    saved_vm_dirty_writeback_centisecs=$(cat /proc/sys/vm/dirty_writeback_centisecs)
+
+    log_must sudo /bin/sh -c "echo 1 > /proc/sys/vm/dirty_expire_centisecs"
+    log_must sudo /bin/sh -c "echo 1 > /proc/sys/vm/dirty_background_bytes"
+    log_must sudo /bin/sh -c "echo 1 > /proc/sys/vm/dirty_writeback_centisecs"
+
+    log_must $STF_SUITE/tests/functional/page_writeback/msync_test
+
+    sudo /bin/sh -c "echo $saved_vm_dirty_expire_centisecs > /proc/sys/vm/dirty_expire_centisecs"
+    sudo /bin/sh -c "echo $saved_vm_dirty_background_ratio > /proc/sys/vm/dirty_background_ratio"
+    sudo /bin/sh -c "echo $saved_vm_dirty_writeback_centisecs > /proc/sys/vm/dirty_writeback_centisecs"
+
+    log_pass "msync tests passed."
+fi

tests/zfs-tests/tests/functional/page_writeback/setup.ksh

@@ -0,0 +1,36 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or http://www.opensolaris.org/os/licensing.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+# Use is subject to license terms.
+#
+
+#
+# Copyright (c) 2013 by Delphix. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+DISK=${DISKS%% *}
+
+default_setup ${DISK}