fix(zfspv): rounding off the volume size to Gi and Mi

ZFS does not create the zvol if volume size is not multiple of
the volblocksize. There are use cases where customer will create
a PVC with size as 5G, which will be 5 * 1000 * 1000 * 1000 bytes
and this is not the multiple of default volblocksize 8k.

In ZFS, volblocksize and recordsize must be power of 2 from 512B to 1M,
so keeping the size in the form of Gi or Mi should be
sufficient to make volsize multiple of volblocksize/recordsize.

Signed-off-by: Pawan <pawan@mayadata.io>

.travis.yml

@@ -8,6 +8,8 @@ env:
   - MINIKUBE_HOME=$HOME
   - CHANGE_MINIKUBE_NONE_USER=true
   - KUBECONFIG=$HOME/.kube/config
+  - OPENEBS_NAMESPACE=openebs
+  - NodeID=$HOSTNAME
 services:
   - docker
 language: go

changelogs/unreleased/191-pawanpraka1

@@ -0,0 +1 @@
+rounding off the volume size to Gi and Mi

ci/ci-test.sh

@@ -16,9 +16,6 @@
 
 set -e
 
-export OPENEBS_NAMESPACE="openebs"
-export NodeID=$HOSTNAME
-
 ZFS_OPERATOR=deploy/zfs-operator.yaml
 SNAP_CLASS=deploy/sample/zfssnapclass.yaml
 

go.mod

@@ -22,6 +22,7 @@ require (
 	github.com/pkg/errors v0.8.1
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/stretchr/testify v1.5.1
 	golang.org/x/crypto v0.0.0-20190829043050-9756ffdc2472 // indirect
 	golang.org/x/net v0.0.0-20191004110552-13f9640d40b9
 	golang.org/x/sys v0.0.0-20190902133755-9109b7679e13

go.sum

@@ -346,6 +346,8 @@ github.com/stretchr/testify v0.0.0-20151208002404-e3a8ff8ce365/go.mod h1:a8OnRci
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/syndtr/gocapability v0.0.0-20160928074757-e7cb7fa329f4/go.mod h1:hkRG7XYTFWNJGYcbNJQlaLq0fg1yr4J4t/NcTQtrfww=
 github.com/tmc/grpc-websocket-proxy v0.0.0-20170815181823-89b8d40f7ca8/go.mod h1:ncp9v5uamzpCO7NfCPTXjqaC+bZgJeR0sMTm6dMHP7U=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=

pkg/driver/controller.go

@@ -37,6 +37,12 @@ import (
 	zfs "github.com/openebs/zfs-localpv/pkg/zfs"
 )
 
+// size constants
+const (
+	Mi = 1024 * 1024
+	Gi = 1024 * 1024 * 1024
+)
+
 // controller is the server implementation
 // for CSI Controller
 type controller struct {
@@ -75,10 +81,26 @@ func sendEventOrIgnore(pvcName, pvName, capacity, stgType, method string) {
 	}
 }
 
+// getRoundedCapacity rounds the capacity on 1024 base
+func getRoundedCapacity(size int64) int64 {
+
+	/*
+	 * volblocksize and recordsize must be power of 2 from 512B to 1M
+	 * so keeping the size in the form of Gi or Mi should be
+	 * sufficient to make volsize multiple of volblocksize/recordsize.
+	 */
+	if size > Gi {
+		return ((size + Gi - 1) / Gi) * Gi
+	}
+
+	// Keeping minimum allocatable size as 1Mi (1024 * 1024)
+	return ((size + Mi - 1) / Mi) * Mi
+}
+
 // CreateZFSVolume create new zfs volume from csi volume request
 func CreateZFSVolume(req *csi.CreateVolumeRequest) (string, error) {
 	volName := req.GetName()
-	size := req.GetCapacityRange().RequiredBytes
+	size := getRoundedCapacity(req.GetCapacityRange().RequiredBytes)
 
 	// parameter keys may be mistyped from the CRD specification when declaring
 	// the storageclass, which kubectl validation will not catch. Because ZFS
@@ -148,7 +170,7 @@ func CreateZFSClone(req *csi.CreateVolumeRequest, snapshot string) (string, erro
 	parameters := req.GetParameters()
 	// lower case keys, cf CreateZFSVolume()
 	pool := helpers.GetInsensitiveParameter(&parameters, "poolname")
-	size := req.GetCapacityRange().RequiredBytes
+	size := getRoundedCapacity(req.GetCapacityRange().RequiredBytes)
 	volsize := strconv.FormatInt(int64(size), 10)
 
 	snapshotID := strings.Split(snapshot, "@")
@@ -208,7 +230,7 @@ func (cs *controller) CreateVolume(
 	parameters := req.GetParameters()
 	// lower case keys, cf CreateZFSVolume()
 	pool := helpers.GetInsensitiveParameter(&parameters, "poolname")
-	size := req.GetCapacityRange().RequiredBytes
+	size := getRoundedCapacity(req.GetCapacityRange().RequiredBytes)
 	contentSource := req.GetVolumeContentSource()
 	pvcName := helpers.GetInsensitiveParameter(&parameters, "csi.storage.k8s.io/pvc/name")
 
@@ -325,7 +347,8 @@ func (cs *controller) ControllerExpandVolume(
 	req *csi.ControllerExpandVolumeRequest,
 ) (*csi.ControllerExpandVolumeResponse, error) {
 
-	updatedSize := req.GetCapacityRange().GetRequiredBytes()
+	/* round off the new size */
+	updatedSize := getRoundedCapacity(req.GetCapacityRange().GetRequiredBytes())
 
 	vol, err := zfs.GetZFSVolume(req.VolumeId)
 	if err != nil {

pkg/driver/controller_test.go

@@ -0,0 +1,44 @@
+/*
+Copyright 2020 The OpenEBS 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 driver
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRoundOff(t *testing.T) {
+
+	tests := map[string]struct {
+		input    int64
+		expected int64
+	}{
+		"Minimum allocatable is 1Mi": {input: 1, expected: Mi},
+		"Minimum allocatable is 1Mi": {input: 1, expected: Mi},
+		"roundOff to same Mi size":   {input: Mi, expected: Mi},
+		"roundOff to nearest Mi":     {input: Mi + 1, expected: Mi * 2},
+		"roundOff to same Gi size":   {input: Gi, expected: Gi},
+		"roundOff to nearest Gi":     {input: Gi + 1, expected: Gi * 2},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			assert.Equal(t, test.expected, getRoundedCapacity(test.input))
+		})
+	}
+}