rbd: add support for RbdImageOptions

There are several RbdImageOptions that can be used to configure features
of an RBD image while creating, cloning, migrating and copying. A
follow-up patch will add Create4() where the RbdImageOptions can be
used.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

rbd/options.go

@@ -0,0 +1,122 @@
+package rbd
+
+// #cgo LDFLAGS: -lrbd
+// #include <stdlib.h>
+// #include <rbd/librbd.h>
+import "C"
+
+import (
+	"fmt"
+	"unsafe"
+)
+
+const (
+	// RBD image options.
+	RbdImageOptionFormat            = C.RBD_IMAGE_OPTION_FORMAT
+	RbdImageOptionFeatures          = C.RBD_IMAGE_OPTION_FEATURES
+	RbdImageOptionOrder             = C.RBD_IMAGE_OPTION_ORDER
+	RbdImageOptionStripeUnit        = C.RBD_IMAGE_OPTION_STRIPE_UNIT
+	RbdImageOptionStripeCount       = C.RBD_IMAGE_OPTION_STRIPE_COUNT
+	RbdImageOptionJournalOrder      = C.RBD_IMAGE_OPTION_JOURNAL_ORDER
+	RbdImageOptionJournalSplayWidth = C.RBD_IMAGE_OPTION_JOURNAL_SPLAY_WIDTH
+	RbdImageOptionJournalPool       = C.RBD_IMAGE_OPTION_JOURNAL_POOL
+	RbdImageOptionFeaturesSet       = C.RBD_IMAGE_OPTION_FEATURES_SET
+	RbdImageOptionFeaturesClear     = C.RBD_IMAGE_OPTION_FEATURES_CLEAR
+	RbdImageOptionDataPool          = C.RBD_IMAGE_OPTION_DATA_POOL
+	// introduced with Ceph Mimic
+	//RbdImageOptionFlatten = C.RBD_IMAGE_OPTION_FLATTEN
+)
+
+type RbdImageOptions struct {
+	options C.rbd_image_options_t
+}
+
+type RbdImageOption C.int
+
+func NewRbdImageOptions() *RbdImageOptions {
+	rio := &RbdImageOptions{}
+	C.rbd_image_options_create(&rio.options)
+	return rio
+}
+
+func (rio *RbdImageOptions) Destroy() {
+	C.rbd_image_options_destroy(rio.options)
+}
+
+func (rio *RbdImageOptions) SetString(option RbdImageOption, value string) error {
+	c_value := C.CString(value)
+	defer C.free(unsafe.Pointer(c_value))
+
+	ret := C.rbd_image_options_set_string(rio.options, C.int(option), c_value)
+	if ret != 0 {
+		return fmt.Errorf("%v, could not set option %v to \"%v\"",
+			GetError(ret), option, value)
+	}
+
+	return nil
+}
+
+func (rio *RbdImageOptions) GetString(option RbdImageOption) (string, error) {
+	value := make([]byte, 4096)
+
+	ret := C.rbd_image_options_get_string(rio.options, C.int(option),
+		(*C.char)(unsafe.Pointer(&value[0])),
+		C.size_t(len(value)))
+	if ret != 0 {
+		return "", fmt.Errorf("%v, could not get option %v", GetError(ret), option)
+	}
+
+	return C.GoString((*C.char)(unsafe.Pointer(&value[0]))), nil
+}
+
+func (rio *RbdImageOptions) SetUint64(option RbdImageOption, value uint64) error {
+	c_value := C.uint64_t(value)
+
+	ret := C.rbd_image_options_set_uint64(rio.options, C.int(option), c_value)
+	if ret != 0 {
+		return fmt.Errorf("%v, could not set option %v to \"%v\"",
+			GetError(ret), option, value)
+	}
+
+	return nil
+}
+
+func (rio *RbdImageOptions) GetUint64(option RbdImageOption) (uint64, error) {
+	var c_value C.uint64_t
+
+	ret := C.rbd_image_options_get_uint64(rio.options, C.int(option), &c_value)
+	if ret != 0 {
+		return 0, fmt.Errorf("%v, could not get option %v", GetError(ret), option)
+	}
+
+	return uint64(c_value), nil
+}
+
+func (rio *RbdImageOptions) IsSet(option RbdImageOption) (bool, error) {
+	var c_set C.bool
+
+	ret := C.rbd_image_options_is_set(rio.options, C.int(option), &c_set)
+	if ret != 0 {
+		return false, fmt.Errorf("%v, could not check option %v", GetError(ret), option)
+	}
+
+	return bool(c_set), nil
+}
+
+func (rio *RbdImageOptions) Unset(option RbdImageOption) error {
+	ret := C.rbd_image_options_unset(rio.options, C.int(option))
+	if ret != 0 {
+		return fmt.Errorf("%v, could not unset option %v", GetError(ret), option)
+	}
+
+	return nil
+}
+
+func (rio *RbdImageOptions) Clear() {
+	C.rbd_image_options_clear(rio.options)
+}
+
+func (rio *RbdImageOptions) IsEmpty() bool {
+	ret := C.rbd_image_options_is_empty(rio.options)
+	return ret != 0
+}

rbd/options_test.go

@@ -0,0 +1,155 @@
+package rbd_test
+
+import (
+	"github.com/ceph/go-ceph/rbd"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestRbdOptions(t *testing.T) {
+	var i uint64
+	var s string
+	var err error
+
+	options := rbd.NewRbdImageOptions()
+	defer options.Destroy()
+
+	err = options.SetUint64(rbd.RbdImageOptionFormat, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionFormat, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionFormat)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionFormat)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionFeatures, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionFeatures, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionFeatures)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionFeatures)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionOrder, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionOrder, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionOrder)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionOrder)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionStripeUnit, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionStripeUnit, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionStripeUnit)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionStripeUnit)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionStripeCount, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionStripeCount, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionStripeCount)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionStripeCount)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionJournalOrder, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionJournalOrder, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionJournalOrder)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionJournalOrder)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionJournalSplayWidth, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionJournalSplayWidth, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionJournalSplayWidth)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionJournalSplayWidth)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionJournalPool, 1)
+	assert.Error(t, err)
+	err = options.SetString(rbd.RbdImageOptionJournalPool, "journal")
+	assert.NoError(t, err)
+	_, err = options.GetUint64(rbd.RbdImageOptionJournalPool)
+	assert.Error(t, err)
+	s, err = options.GetString(rbd.RbdImageOptionJournalPool)
+	assert.NoError(t, err)
+	assert.True(t, s == "journal")
+
+	err = options.SetUint64(rbd.RbdImageOptionFeaturesSet, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionFeaturesSet, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionFeaturesSet)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionFeaturesSet)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionFeaturesClear, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionFeaturesClear, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionFeaturesClear)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionFeaturesClear)
+	assert.Error(t, err)
+
+	err = options.SetUint64(rbd.RbdImageOptionDataPool, 1)
+	assert.Error(t, err)
+	err = options.SetString(rbd.RbdImageOptionDataPool, "data")
+	assert.NoError(t, err)
+	_, err = options.GetUint64(rbd.RbdImageOptionDataPool)
+	assert.Error(t, err)
+	s, err = options.GetString(rbd.RbdImageOptionDataPool)
+	assert.NoError(t, err)
+	assert.True(t, s == "data")
+
+	/* introduced with Ceph Mimic, can not be tested on Luminous
+	err = options.SetUint64(rbd.RbdImageOptionFlatten, 1)
+	assert.NoError(t, err)
+	err = options.SetString(rbd.RbdImageOptionFlatten, "string not allowed")
+	assert.Error(t, err)
+	i, err = options.GetUint64(rbd.RbdImageOptionFlatten)
+	assert.NoError(t, err)
+	assert.True(t, i == 1)
+	_, err = options.GetString(rbd.RbdImageOptionFlatten)
+	assert.Error(t, err)
+	*/
+}
+
+func TestRbdOptionsClear(t *testing.T) {
+	options := rbd.NewRbdImageOptions()
+
+	// set at least one option
+	err := options.SetUint64(rbd.RbdImageOptionFormat, 1)
+	assert.NoError(t, err)
+
+	empty := options.IsEmpty()
+	assert.False(t, empty)
+
+	options.Clear()
+	empty = options.IsEmpty()
+	assert.True(t, empty)
+
+	options.Destroy()
+}