[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/go.etcd.io/etcd/mvcc/backend/config_linux.go b/vendor/go.etcd.io/etcd/mvcc/backend/config_linux.go
new file mode 100644
index 0000000..f712671
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/mvcc/backend/config_linux.go
@@ -0,0 +1,34 @@
+// Copyright 2015 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package backend
+
+import (
+	"syscall"
+
+	bolt "go.etcd.io/bbolt"
+)
+
+// syscall.MAP_POPULATE on linux 2.6.23+ does sequential read-ahead
+// which can speed up entire-database read with boltdb. We want to
+// enable MAP_POPULATE for faster key-value store recovery in storage
+// package. If your kernel version is lower than 2.6.23
+// (https://github.com/torvalds/linux/releases/tag/v2.6.23), mmap might
+// silently ignore this flag. Please update your kernel to prevent this.
+var boltOpenOptions = &bolt.Options{
+	MmapFlags:      syscall.MAP_POPULATE,
+	NoFreelistSync: true,
+}
+
+func (bcfg *BackendConfig) mmapSize() int { return int(bcfg.MmapSize) }