diff --git a/.gitignore b/.gitignore
index efc73a7c..936955e0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -126,6 +126,7 @@
 /src/t_immutable
 /src/t_locks_execve
 /src/t_mmap_cow_race
+/src/t_mmap_collision
 /src/t_mmap_dio
 /src/t_mmap_fallocate
 /src/t_mmap_stale_pmd
diff --git a/src/Makefile b/src/Makefile
index b06b7e25..2dbe5e7e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -15,7 +15,7 @@ TARGETS = dirstress fill fill2 getpagesize holes lstat64 \
 	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_ext4_dax_journal_corruption t_ext4_dax_inline_corruption \
-	t_ofd_locks t_locks_execve
+	t_ofd_locks t_locks_execve t_mmap_collision
 
 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_mmap_collision.c b/src/t_mmap_collision.c
new file mode 100644
index 00000000..f652e913
--- /dev/null
+++ b/src/t_mmap_collision.c
@@ -0,0 +1,208 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdbool.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 PAGE(a) ((a)*0x1000)
+#define FILE_SIZE PAGE(4)
+
+void *dax_data;
+int nodax_fd;
+int dax_fd;
+bool done;
+
+#define err_exit(op)                                                          \
+{                                                                             \
+	fprintf(stderr, "%s %s: %s\n", __func__, op, strerror(errno));        \
+	exit(1);                                                              \
+}                                                                             \
+
+void punch_hole_fn(void *ptr)
+{
+	ssize_t read;
+	int rc;
+
+	while (!done) {
+		read = 0;
+
+		do {
+			rc = pread(nodax_fd, dax_data + read, FILE_SIZE - read,
+					read);
+			if (rc > 0)
+				read += rc;
+		} while (rc > 0);
+
+		if (read != FILE_SIZE || rc != 0)
+			err_exit("pread");
+
+		rc = fallocate(dax_fd,
+				FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+				0, FILE_SIZE);
+		if (rc < 0)
+			err_exit("fallocate");
+
+		usleep(rand() % 1000);
+	}
+}
+
+void zero_range_fn(void *ptr)
+{
+	ssize_t read;
+	int rc;
+
+	while (!done) {
+		read = 0;
+
+		do {
+			rc = pread(nodax_fd, dax_data + read, FILE_SIZE - read,
+					read);
+			if (rc > 0)
+				read += rc;
+		} while (rc > 0);
+
+		if (read != FILE_SIZE || rc != 0)
+			err_exit("pread");
+
+		rc = fallocate(dax_fd,
+				FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE,
+				0, FILE_SIZE);
+		if (rc < 0)
+			err_exit("fallocate");
+
+		usleep(rand() % 1000);
+	}
+}
+
+void truncate_down_fn(void *ptr)
+{
+	ssize_t read;
+	int rc;
+
+	while (!done) {
+		read = 0;
+
+		if (ftruncate(dax_fd, 0) < 0)
+			err_exit("ftruncate");
+		if (fallocate(dax_fd, 0, 0, FILE_SIZE) < 0)
+			err_exit("fallocate");
+
+		do {
+			rc = pread(nodax_fd, dax_data + read, FILE_SIZE - read,
+					read);
+			if (rc > 0)
+				read += rc;
+		} while (rc > 0);
+
+		/*
+		 * For this test we ignore errors from pread().  These errors
+		 * can happen if we try and read while the other thread has
+		 * made the file size 0.
+		 */
+
+		usleep(rand() % 1000);
+	}
+}
+
+void collapse_range_fn(void *ptr)
+{
+	ssize_t read;
+	int rc;
+
+	while (!done) {
+		read = 0;
+
+		if (fallocate(dax_fd, 0, 0, FILE_SIZE) < 0)
+			err_exit("fallocate 1");
+		if (fallocate(dax_fd, FALLOC_FL_COLLAPSE_RANGE, 0, PAGE(1)) < 0)
+			err_exit("fallocate 2");
+		if (fallocate(dax_fd, 0, 0, FILE_SIZE) < 0)
+			err_exit("fallocate 3");
+
+		do {
+			rc = pread(nodax_fd, dax_data + read, FILE_SIZE - read,
+					read);
+			if (rc > 0)
+				read += rc;
+		} while (rc > 0);
+
+		/* For this test we ignore errors from pread. */
+
+		usleep(rand() % 1000);
+	}
+}
+
+void run_test(void (*test_fn)(void *))
+{
+	const int NUM_THREADS = 2;
+	pthread_t worker_thread[NUM_THREADS];
+	int i;
+
+	done = 0;
+	for (i = 0; i < NUM_THREADS; i++)
+		pthread_create(&worker_thread[i], NULL, (void*)test_fn, NULL);
+
+	sleep(1);
+	done = 1;
+
+	for (i = 0; i < NUM_THREADS; i++)
+		pthread_join(worker_thread[i], NULL);
+}
+
+int main(int argc, char *argv[])
+{
+	int err;
+
+	if (argc != 3) {
+		printf("Usage: %s <dax file> <non-dax file>\n",
+				basename(argv[0]));
+		exit(0);
+	}
+
+	dax_fd = open(argv[1], O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
+	if (dax_fd < 0)
+		err_exit("dax_fd open");
+
+	nodax_fd = open(argv[2], O_RDWR|O_CREAT|O_DIRECT, S_IRUSR|S_IWUSR);
+	if (nodax_fd < 0)
+		err_exit("nodax_fd open");
+
+	if (ftruncate(dax_fd, 0) < 0)
+		err_exit("dax_fd ftruncate");
+	if (fallocate(dax_fd, 0, 0, FILE_SIZE) < 0)
+		err_exit("dax_fd fallocate");
+
+	if (ftruncate(nodax_fd, 0) < 0)
+		err_exit("nodax_fd ftruncate");
+	if (fallocate(nodax_fd, 0, 0, FILE_SIZE) < 0)
+		err_exit("nodax_fd fallocate");
+
+	dax_data = mmap(NULL, FILE_SIZE, PROT_READ|PROT_WRITE, MAP_SHARED,
+			dax_fd, 0);
+	if (dax_data == MAP_FAILED)
+		err_exit("mmap");
+
+	run_test(&punch_hole_fn);
+	run_test(&zero_range_fn);
+	run_test(&truncate_down_fn);
+	run_test(&collapse_range_fn);
+
+	if (munmap(dax_data, FILE_SIZE) != 0)
+		err_exit("munmap");
+
+	err = close(dax_fd);
+	if (err < 0)
+		err_exit("dax_fd close");
+
+	err = close(nodax_fd);
+	if (err < 0)
+		err_exit("nodax_fd close");
+
+	return 0;
+}
diff --git a/tests/generic/999 b/tests/generic/999
new file mode 100755
index 00000000..8f488cb5
--- /dev/null
+++ b/tests/generic/999
@@ -0,0 +1,50 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2018 Intel Corporation.  All Rights Reserved.
+#
+# FS QA Test generic/999
+#
+# This is a regression test for kernel patch:
+#   ext4: handle layout changes to pinned DAX mapping
+# created by Ross Zwisler <ross.zwisler@linux.intel.com>
+#
+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
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# Modify as appropriate.
+_supported_fs generic
+_supported_os Linux
+_require_test
+_require_test_program "t_mmap_collision"
+
+# turn off DAX on our scratch device so we can get normal O_DIRECT behavior
+export MOUNT_OPTIONS=""
+_scratch_unmount >> $seqres.full 2>&1
+_scratch_mount >> $seqres.full 2>&1
+
+# real QA test starts here
+$here/src/t_mmap_collision $TEST_DIR/testfile $SCRATCH_MNT/testfile
+
+# success, all done
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/generic/999.out b/tests/generic/999.out
new file mode 100644
index 00000000..3b276ca8
--- /dev/null
+++ b/tests/generic/999.out
@@ -0,0 +1,2 @@
+QA output created by 999
+Silence is golden
diff --git a/tests/generic/group b/tests/generic/group
index 83a6fdab..793f71ed 100644
--- a/tests/generic/group
+++ b/tests/generic/group
@@ -501,3 +501,4 @@
 496 auto quick swap
 497 auto quick swap collapse
 498 auto quick log
+999 auto quick dax
