diff --git a/README b/README
index 9f01aa1..0f98035 100644
--- a/README
+++ b/README
@@ -78,6 +78,11 @@
 	     - setenv TEST_LOGDEV "device for test-fs external log"
              - setenv TEST_RTDEV "device for test-fs realtime data"
              - if TEST_LOGDEV and/or TEST_RTDEV, these will always be used.
+             - set IDMAPPED_MOUNTS=true to run all tests on top of idmapped
+               mounts. While this option is supported for all filesystems
+               currently only -overlay is expected to run without issues. For
+               other filesystems additional patches and fixes to the test suite
+               might be needed.
              - if SCRATCH_LOGDEV and/or SCRATCH_RTDEV, the USE_EXTERNAL
                environment variable set to "yes" will enable their use.
              - setenv DIFF_LENGTH "number of diff lines to print from a failed test",
diff --git a/README.overlay b/README.overlay
index 39e25ad..ec4671c 100644
--- a/README.overlay
+++ b/README.overlay
@@ -31,7 +31,8 @@
 do not change FSTYP and MKFS_OPTIONS can be safely used with -overlay.
 
 For example, the following multi-section config file can be used to
-run overlay tests on the same base fs, but with different mount options:
+run overlay tests on the same base fs, but with different mount options, and on
+top of idmapped mounts:
 
  [xfs]
  TEST_DEV=/dev/sda5
@@ -46,6 +47,9 @@
  OVERLAY_MOUNT_OPTIONS="-o redirect_dir=off"
  OVERLAY_FSCK_OPTIONS="-n -o redirect_dir=off"
 
+ [idmapped]
+ IDMAPPED_MOUNTS=true
+
 In the example above, MOUNT_OPTIONS will be used to mount the base scratch fs,
 TEST_FS_MOUNT_OPTS will be used to mount the base test fs,
 OVERLAY_MOUNT_OPTIONS will be used to mount both test and scratch overlay and
diff --git a/common/config b/common/config
index 479e50d..1033b89 100644
--- a/common/config
+++ b/common/config
@@ -647,6 +647,7 @@
 	# Set fsck options, use default if user not set directly.
 	export FSCK_OPTIONS="$OVERLAY_FSCK_OPTIONS"
 	[ -z "$FSCK_OPTIONS" ] && _fsck_opts
+	export IDMAPPED_MOUNTS="$IDMAPPED_MOUNTS"
 }
 
 _overlay_config_restore()
diff --git a/common/overlay b/common/overlay
index 1ca37e2..fff67ba 100644
--- a/common/overlay
+++ b/common/overlay
@@ -73,6 +73,7 @@
 
 	if [ -z "$dev" -o -z "$mnt" ] || \
 		_check_mounted_on $devname $dev $mntname $mnt; then
+		_idmapped_mount $dev $mnt
 		# no base fs or already mounted
 		return 0
 	elif [ $? -ne 1 ]; then
@@ -81,6 +82,7 @@
 	fi
 
 	_mount $* $dev $mnt
+	_idmapped_mount $dev $mnt
 }
 
 _overlay_base_test_mount()
diff --git a/common/rc b/common/rc
index faf54ef..5090cbf 100644
--- a/common/rc
+++ b/common/rc
@@ -334,6 +334,7 @@
 		return $?
 	fi
 	_mount -t $FSTYP `_scratch_mount_options $*`
+	_idmapped_mount $SCRATCH_DEV $SCRATCH_MNT
 }
 
 # mount scratch device with given options and _fail if mount fails
@@ -444,6 +445,53 @@
 	fi
 }
 
+_move_mount()
+{
+	local mnt=$1
+	local tmp=$2
+
+	# Replace $mnt with $tmp. Use a temporary bind-mount because
+	# mount --move will fail with certain mount propagation layouts.
+	$UMOUNT_PROG $mnt || _fail "Failed to unmount $mnt"
+	_mount --bind $tmp $mnt || _fail "Failed to bind-mount $tmp to $mnt"
+	$UMOUNT_PROG $tmp || _fail "Failed to unmount $tmp"
+	rmdir $tmp
+}
+
+_idmapped_mount()
+{
+	[ "$IDMAPPED_MOUNTS" = "true" ] || return 0
+
+	local dev=$1
+	local mnt=$2
+	local status=0
+	local tmp=`mktemp -d`
+
+	local mount_rec=`findmnt -rncv -S $dev -o OPTIONS`
+	if [[ "$mount_rec" == *"idmapped"* ]]; then
+		return 0
+	fi
+
+	# We create an idmapped mount where {g,u}id 0 writes to disk as
+	# {g,u}id 10000000 and $(id -u fsgqa) + 10000000. We change ownership
+        # of $mnt so {g,u} id 0 can actually create objects in there.
+	chown 10000000:10000000 $mnt || return 1
+	$here/src/idmapped-mounts/mount-idmapped \
+		--map-mount b:10000000:0:100000000000 \
+		$mnt $tmp
+	if [ $? -ne 0 ]; then
+		rmdir $tmp
+		return 1
+	fi
+
+	# The next call ensures we don't end up stacking an idmapped mount on
+	# top of the original mount. Instead we fully replace the original
+	# mount with the idmapped mount. This will not just allow a clean mount
+        # layout it also makes unmount and remounting way simpler.
+	_move_mount $mnt $tmp
+	return $?
+}
+
 _test_mount()
 {
     if [ "$FSTYP" == "overlay" ]; then
@@ -452,6 +500,7 @@
     fi
     _test_options mount
     _mount -t $FSTYP $TEST_OPTIONS $TEST_FS_MOUNT_OPTS $SELINUX_MOUNT_OPTIONS $* $TEST_DEV $TEST_DIR
+    _idmapped_mount $TEST_DEV $TEST_DIR
 }
 
 _test_unmount()
@@ -3007,6 +3056,7 @@
 	if [ $USE_REMOUNT -eq 0 ]; then
 		if [ "$FSTYP" != "overlay" ]; then
 			_mount -t $FSTYP $mount_opts $device $mountpoint
+			_idmapped_mount $device $mountpoint
 		else
 			_overlay_mount $device $mountpoint
 		fi