rbd: add support for rbd striping

RBD supports creating rbd images with
object size, stripe unit and stripe count
to support striping. This PR adds the support
for the same.

More details about striping at
https://docs.ceph.com/en/quincy/man/8/rbd/#striping

fixes: #3124

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

internal/rbd/controllerserver.go

@@ -20,6 +20,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"strconv"
 
 	csicommon "github.com/ceph/ceph-csi/internal/csi-common"
 	"github.com/ceph/ceph-csi/internal/util"
@@ -94,6 +95,43 @@ func (cs *ControllerServer) validateVolumeReq(ctx context.Context, req *csi.Crea
 		return err
 	}
 
+	err = validateStriping(req.Parameters)
+	if err != nil {
+		return status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	return nil
+}
+
+func validateStriping(parameters map[string]string) error {
+	stripeUnit := parameters["stripeUnit"]
+	stripeCount := parameters["stripeCount"]
+	if stripeUnit != "" && stripeCount == "" {
+		return errors.New("stripeCount must be specified when stripeUnit is specified")
+	}
+
+	if stripeUnit == "" && stripeCount != "" {
+		return errors.New("stripeUnit must be specified when stripeCount is specified")
+	}
+
+	objectSize := parameters["objectSize"]
+	if objectSize != "" {
+		objSize, err := strconv.ParseUint(objectSize, 10, 64)
+		if err != nil {
+			return fmt.Errorf("failed to parse objectSize %s: %w", objectSize, err)
+		}
+		// check objectSize is power of 2
+		/*
+			Take 2^3=8 for example.
+			x & (x-1)
+			8 & 7
+			1000 & 0111 = 0000
+		*/
+		if objSize == 0 || (objSize&(objSize-1)) != 0 {
+			return fmt.Errorf("objectSize %s is not power of 2", objectSize)
+		}
+	}
+
 	return nil
 }