diff --git a/.gitignore b/.gitignore
index 2014c08..9fc0695 100644
--- a/.gitignore
+++ b/.gitignore
@@ -119,6 +119,7 @@
 /src/t_getcwd
 /src/t_holes
 /src/t_immutable
+/src/t_map_sync
 /src/t_mmap_cow_race
 /src/t_mmap_dio
 /src/t_mmap_fallocate
diff --git a/common/dmlogwrites b/common/dmlogwrites
index 247c744..5b57df9 100644
--- a/common/dmlogwrites
+++ b/common/dmlogwrites
@@ -23,7 +23,6 @@ _require_log_writes()
 	[ -z "$LOGWRITES_DEV" -o ! -b "$LOGWRITES_DEV" ] && \
 		_notrun "This test requires a valid \$LOGWRITES_DEV"
 
-	_exclude_scratch_mount_option dax
 	_require_dm_target log-writes
 	_require_test_program "log-writes/replay-log"
 }
diff --git a/src/Makefile b/src/Makefile
index 3eb25b1..af7e7e9 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -13,7 +13,8 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
 	multi_open_unlink dmiperf unwritten_sync genhashnames t_holes \
 	t_mmap_writev t_truncate_cmtime dirhash_collide t_rename_overwrite \
 	holetest t_truncate_self t_mmap_dio af_unix t_mmap_stale_pmd \
-	t_mmap_cow_race t_mmap_fallocate fsync-err t_mmap_write_ro
+	t_mmap_cow_race t_mmap_fallocate fsync-err t_mmap_write_ro \
+	t_map_sync
 
 LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
 	preallo_rw_pattern_writer ftrunc trunc fs_perms testx looptest \
diff --git a/src/t_map_sync.c b/src/t_map_sync.c
new file mode 100644
index 0000000..8190f3c
--- /dev/null
+++ b/src/t_map_sync.c
@@ -0,0 +1,74 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#define MiB(a) ((a)*1024*1024)
+
+/*
+ * These two defines were added to the kernel via commits entitled
+ * "mm: Define MAP_SYNC and VM_SYNC flags" and
+ * "mm: introduce MAP_SHARED_VALIDATE, a mechanism to safely define new mmap
+ * flags", respectively.
+ */
+#define MAP_SYNC 0x80000
+#define MAP_SHARED_VALIDATE 0x3
+
+void err_exit(char *op)
+{
+	fprintf(stderr, "%s: %s\n", op, strerror(errno));
+	exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+	int page_size = getpagesize();
+	int len = MiB(1);
+	int i, fd, err;
+	char *data;
+
+	if (argc < 2) {
+		printf("Usage: %s <file>\n", basename(argv[0]));
+		exit(0);
+	}
+
+	fd = open(argv[1], O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
+	if (fd < 0)
+		err_exit("fd");
+
+	ftruncate(fd, 0);
+	ftruncate(fd, len);
+
+	data = mmap(NULL, len, PROT_READ|PROT_WRITE,
+			MAP_SHARED_VALIDATE|MAP_SYNC, fd, 0);
+	if (data == MAP_FAILED)
+		err_exit("mmap");
+
+	/*
+	 * We intentionally don't sync 'fd' manually.  If MAP_SYNC is working
+	 * these allocating page faults will cause the filesystem to sync its
+	 * metadata so that when we replay the dm-log-writes log the test file
+	 * will be 1 MiB in size.
+	 *
+	 * dm-log-writes doesn't track the data that we write via the mmap(),
+	 * so we can't check that, we can only verify that the metadata writes
+	 * happened.
+	 */
+	for (i = 0; i < len; i+=page_size)
+		data[i] = 0xff;
+
+	err = munmap(data, len);
+	if (err < 0)
+		err_exit("munmap");
+
+	err = close(fd);
+	if (err < 0)
+		err_exit("close");
+
+	return 0;
+}
diff --git a/tests/generic/466 b/tests/generic/466
new file mode 100755
index 0000000..f39e6dc
--- /dev/null
+++ b/tests/generic/466
@@ -0,0 +1,77 @@
+#! /bin/bash
+# FS QA Test No. 466
+#
+# Use md_log_writes to verify that MAP_SYNC actually syncs metadata during
+# page faults.
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Intel Corporation.  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`
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	_log_writes_cleanup
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/dmlogwrites
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_log_writes
+_require_scratch_dax
+_require_test_program "t_map_sync"
+
+_log_writes_init
+_log_writes_mkfs >> $seqres.full 2>&1
+_log_writes_mount -o dax
+
+src/t_map_sync $SCRATCH_MNT/test
+
+# Unmount the scratch dir and tear down the log writes target
+_log_writes_mark last
+_log_writes_unmount
+_log_writes_remove
+_check_scratch_fs
+
+# check pre umount
+_log_writes_replay_log last
+_scratch_mount
+
+# We should see $SCRATCH_MNT/test as 1MiB in size
+du -sh $SCRATCH_MNT/test | _filter_scratch | _filter_spaces
+
+_scratch_unmount
+_check_scratch_fs
+
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/generic/466.out b/tests/generic/466.out
new file mode 100644
index 0000000..4c54d7a
--- /dev/null
+++ b/tests/generic/466.out
@@ -0,0 +1,3 @@
+QA output created by 466
+1.0M SCRATCH_MNT/test
+Silence is golden
diff --git a/tests/generic/group b/tests/generic/group
index fbe0a7f..65328c6 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -468,3 +468,4 @@
 463 auto quick clone dangerous
 464 auto rw
 465 auto rw quick aio
+466 auto quick dax
