diff --git a/README b/README
index bb42985..842e835 100644
--- a/README
+++ b/README
@@ -117,16 +117,18 @@ Running tests:
     - By default the tests suite will run xfs tests:
     - ./check '*/001' '*/002' '*/003'
     - ./check '*/06?'
-    - You can explicitly specify NFS/CIFS/UDF, otherwise the filesystem type will
-      be autodetected from $TEST_DEV:
-      ./check -nfs [test(s)]
     - Groups of tests maybe ran by: ./check -g [group(s)]
       See the 'group' file for details on groups
-    - for udf tests: ./check -udf [test(s)]
-      Running all the udf tests: ./check -udf -g udf
-    - for running nfs tests: ./check -nfs [test(s)]
-    - for running cifs/smb3 tests: ./check -cifs [test(s)]
     - To randomize test order: ./check -r [test(s)]
+    - You can explicitly specify NFS/CIFS/UDF/OVERLAY, otherwise
+      the filesystem type will be autodetected from $TEST_DEV:
+        - for running nfs tests: ./check -nfs [test(s)]
+        - for running cifs/smb3 tests: ./check -cifs [test(s)]
+        - for udf tests: ./check -udf [test(s)]
+          Running all the udf tests: ./check -udf -g udf
+        - for overlay tests: ./check -overlay [test(s)]
+          The TEST and SCRATCH partitions should be pre-formatted
+          with another base fs, where the overlay dirs will be created
 
     
     The check script tests the return value of each script, and
diff --git a/check b/check
index ec9798a..c51fc0c 100755
--- a/check
+++ b/check
@@ -258,7 +258,7 @@ while [ $# -gt 0 ]; do
 
 	-nfs)		FSTYP=nfs ;;
 	-cifs)		FSTYP=cifs ;;
-	-overlay)	FSTYP=overlay ;;
+	-overlay)	FSTYP=overlay; export OVERLAY=true ;;
 	-tmpfs)		FSTYP=tmpfs ;;
 
 	-g)	group=$2 ; shift ;
diff --git a/common/config b/common/config
index a7ab2d9..5d90138 100644
--- a/common/config
+++ b/common/config
@@ -82,6 +82,8 @@ export DEBUGFS_MNT=${DEBUGFS_MNT:="/sys/kernel/debug"}
 export OVL_UPPER="ovl-upper"
 export OVL_LOWER="ovl-lower"
 export OVL_WORK="ovl-work"
+# overlay mount point parent must be the base fs root
+export OVL_MNT="ovl-mnt"
 
 export PWD=`pwd`
 #export DEBUG=${DEBUG:=...} # arbitrary CFLAGS really.
@@ -462,12 +464,68 @@ _canonicalize_mountpoint()
 	local name=$1
 	local dir=$2
 
-	if [ ! -d "$dir" ]; then
+	if [ -d "$dir" ]; then
+		# this follows symlinks and removes all trailing "/"s
+		readlink -e "$dir"
+		return 0
+	fi
+
+	if [ "$FSTYP" != "overlay" ] || [[ "$name" == OVL_BASE_* ]]; then
 		_fatal "common/config: $name ($dir) is not a directory"
 	fi
 
-	# this follows symlinks and removes all trailing "/"s
-	readlink -e "$dir"
+	# base fs may not be mounted yet, so just check that parent dir
+	# exists (where base fs will be mounted) because we are going to
+	# mkdir the overlay mount point dir anyway
+	local base=`basename $dir`
+	local parent=`dirname $dir`
+	local parent=`_canonicalize_mountpoint OVL_BASE_$name "$parent"`
+
+	# prepend the overlay mount point to canonical parent path
+	echo "$parent/$base"
+}
+
+_config_overlay()
+{
+	# There are 2 options for configuring overlayfs tests:
+	#
+	# 1. (legacy) SCRATCH/TEST_DEV point to existing directories
+	#    on an already mounted fs.  In this case, the new
+	#    OVL_BASE_SCRATCH/TEST_* vars are set to use the legacy
+	#    vars values (even though they may not be mount points).
+	#
+	[ ! -d "$TEST_DEV" ] || export OVL_BASE_TEST_DIR="$TEST_DEV"
+	[ ! -d "$SCRATCH_DEV" ] || export OVL_BASE_SCRATCH_MNT="$SCRATCH_DEV"
+
+	# 2. SCRATCH/TEST_DEV point to the base fs partitions.  In this case,
+	#    the new OVL_BASE_SCRATCH/TEST_DEV/MNT vars are set to the values
+	#    of the configured base fs and SCRATCH/TEST_DEV vars are set to the
+	#    overlayfs base and mount dirs inside base fs mount.
+	[ -b "$TEST_DEV" ] || return 0
+
+	# Config file may specify base fs type, but we obay -overlay flag
+	export OVL_BASE_FSTYP="$FSTYP"
+	export FSTYP=overlay
+
+	# Store original base fs vars
+	export OVL_BASE_TEST_DEV="$TEST_DEV"
+	export OVL_BASE_TEST_DIR=`_canonicalize_mountpoint OVL_BASE_TEST_DIR $TEST_DIR`
+	export OVL_BASE_MOUNT_OPTIONS="$MOUNT_OPTIONS"
+
+	# Set TEST vars to overlay base and mount dirs inside base fs
+	export TEST_DEV="$OVL_BASE_TEST_DIR"
+	export TEST_DIR="$OVL_BASE_TEST_DIR/$OVL_MNT"
+	export MOUNT_OPTIONS="$OVERLAY_MOUNT_OPTIONS"
+
+	[ -b "$SCRATCH_DEV" ] || return 0
+
+	# Store original base fs vars
+	export OVL_BASE_SCRATCH_DEV="$SCRATCH_DEV"
+	export OVL_BASE_SCRATCH_MNT=`_canonicalize_mountpoint OVL_BASE_SCRATCH_MNT $SCRATCH_MNT`
+
+	# Set SCRATCH vars to overlay base and mount dirs inside base fs
+	export SCRATCH_DEV="$OVL_BASE_SCRATCH_MNT"
+	export SCRATCH_MNT="$OVL_BASE_SCRATCH_MNT/$OVL_MNT"
 }
 
 # Parse config section options. This function will parse all the configuration
@@ -516,6 +574,15 @@ get_next_config() {
 		unset SCRATCH_DEV
 	fi
 
+	# We might have overriden TEST/SCRATCH vars with overlay base dir in the
+	# previous run, so restore them to original values stored in OVL_BASE_*
+	if [ "$FSTYP" == "overlay" ]; then
+		[ -z "$OVL_BASE_TEST_DEV" ] || export TEST_DEV=$OVL_BASE_TEST_DEV
+		[ -z "$OVL_BASE_TEST_DIR" ] || export TEST_DIR=$OVL_BASE_TEST_DIR
+		[ -z "$OVL_BASE_SCRATCH_DEV" ] || export SCRATCH_DEV=$OVL_BASE_SCRATCH_DEV
+		[ -z "$OVL_BASE_SCRATCH_MNT" ] || export SCRATCH_MNT=$OVL_BASE_SCRATCH_MNT
+	fi
+
 	parse_config_section $1
 
 	if [ ! -z "$OLD_FSTYP" ] && [ $OLD_FSTYP != $FSTYP ]; then
@@ -544,6 +611,12 @@ get_next_config() {
 		export RESULT_BASE="$here/results/"
 	fi
 
+	# Override FSTYP from config when running ./check -overlay
+	# and maybe derive overlay TEST/SCRATCH from base fs values
+	if [ "$OVERLAY" == "true" -o "$FSTYP" == "overlay" ]; then
+		_config_overlay
+	fi
+
 	#  Mandatory Config values.
 	MC=""
 	[ -z "$EMAIL" ]          && MC="$MC EMAIL"
@@ -601,6 +674,12 @@ if [ -z "$CONFIG_INCLUDED" ]; then
 	[ -z "$MKFS_OPTIONS" ] && _mkfs_opts
 	[ -z "$FSCK_OPTIONS" ] && _fsck_opts
 else
+	# Override FSTYP from config when running ./check -overlay
+	# and maybe derive overlay TEST/SCRATCH from base fs values
+	if [ "$OVERLAY" == "true" -o "$FSTYP" == "overlay" ]; then
+		_config_overlay
+	fi
+
 	# canonicalize the mount points
 	# this follows symlinks and removes all trailing "/"s
 	export TEST_DIR=`_canonicalize_mountpoint TEST_DIR $TEST_DIR`
diff --git a/common/rc b/common/rc
index 4e0cbdf..74168ea 100644
--- a/common/rc
+++ b/common/rc
@@ -257,7 +257,7 @@ _scratch_mount_options()
 	_scratch_options mount
 
 	if [ "$FSTYP" == "overlay" ]; then
-		echo `_overlay_mount_options $SCRATCH_DEV`
+		echo `_overlay_mount_options $OVL_BASE_SCRATCH_MNT`
 		return 0
 	fi
 	echo `_common_dev_mount_options $*` $SCRATCH_OPTIONS \
@@ -308,9 +308,10 @@ _overlay_mkdirs()
 	mkdir -p $dir/$OVL_UPPER
 	mkdir -p $dir/$OVL_LOWER
 	mkdir -p $dir/$OVL_WORK
+	mkdir -p $dir/$OVL_MNT
 }
 
-# Given a dir, set up 3 subdirectories and mount on the given mnt.
+# Given a base fs dir, set up overlay directories and mount on the given mnt.
 # The dir is used as the mount device so it can be seen from df or mount
 _overlay_mount()
 {
@@ -329,12 +330,12 @@ _overlay_mount()
 
 _overlay_test_mount()
 {
-	_overlay_mount $TEST_DEV $TEST_DIR $*
+	_overlay_mount $OVL_BASE_TEST_DIR $TEST_DIR $*
 }
 
 _overlay_scratch_mount()
 {
-	_overlay_mount $SCRATCH_DEV $SCRATCH_MNT $*
+	_overlay_mount $OVL_BASE_SCRATCH_MNT $SCRATCH_MNT $*
 }
 
 _overlay_test_unmount()
@@ -649,10 +650,12 @@ _scratch_cleanup_files()
 {
 	case $FSTYP in
 	overlay)
-		# $SCRATCH_DEV is a valid directory in overlay case
-		rm -rf $SCRATCH_DEV/*
+		# Avoid rm -rf /* if we messed up
+		[ -n "$OVL_BASE_SCRATCH_MNT" ] || return 1
+		rm -rf $OVL_BASE_SCRATCH_MNT/*
 		;;
 	*)
+		[ -n "$SCRATCH_MNT" ] || return 1
 		_scratch_mount
 		rm -rf $SCRATCH_MNT/*
 		_scratch_unmount
@@ -1390,8 +1393,8 @@ _require_scratch_nocheck()
 		fi
 		;;
 	overlay)
-		if [ -z "$SCRATCH_DEV" -o ! -d "$SCRATCH_DEV" ]; then
-			_notrun "this test requires a valid \$SCRATCH_DEV as ovl base dir"
+		if [ -z "$OVL_BASE_SCRATCH_MNT" -o ! -d "$OVL_BASE_SCRATCH_MNT" ]; then
+			_notrun "this test requires a valid \$SCRATCH_MNT as ovl base dir"
 		fi
 		if [ ! -d "$SCRATCH_MNT" ]; then
 			_notrun "this test requires a valid \$SCRATCH_MNT"
@@ -1463,8 +1466,8 @@ _require_test()
 		fi
 		;;
 	overlay)
-		if [ -z "$TEST_DEV" -o ! -d "$TEST_DEV" ]; then
-			_notrun "this test requires a valid \$TEST_DEV as ovl base dir"
+		if [ -z "$OVL_BASE_TEST_DIR" -o ! -d "$OVL_BASE_TEST_DIR" ]; then
+			_notrun "this test requires a valid \$TEST_DIR as ovl base dir"
 		fi
 		if [ ! -d "$TEST_DIR" ]; then
 			_notrun "this test requires a valid \$TEST_DIR"
