rbd: check if mirror image has parent image

[yati1998]

since enable mirroring fails if it has parent image this commit adds a check for that and returns
suitable error which can be picke by VR status

[iPraveenParihar]

@yati1998, parent image check is already handled in HandleParentImageExistence()

ceph-csi/internal/csi-addons/rbd/replication.go

Lines 309 to 322 in c4a1e3a

	if info.GetState() != librbd.MirrorImageEnabled.String() {
	err = rbdVol.HandleParentImageExistence(ctx, flattenMode)
	if err != nil {
	log.ErrorLog(ctx, err.Error())
	return nil, getGRPCError(err)
	}
	err = mirror.EnableMirroring(ctx, mirroringMode)
	if err != nil {
	log.ErrorLog(ctx, err.Error())
	return nil, status.Error(codes.Internal, err.Error())
	}
	}

[yati1998]

@yati1998, parent image check is already handled in HandleParentImageExistence()

ceph-csi/internal/csi-addons/rbd/replication.go

Lines 309 to 322 in c4a1e3a

	if info.GetState() != librbd.MirrorImageEnabled.String() {
	err = rbdVol.HandleParentImageExistence(ctx, flattenMode)
	if err != nil {
	log.ErrorLog(ctx, err.Error())
	return nil, getGRPCError(err)
	}
	err = mirror.EnableMirroring(ctx, mirroringMode)
	if err != nil {
	log.ErrorLog(ctx, err.Error())
	return nil, status.Error(codes.Internal, err.Error())
	}
	}

okay, missed it, it seems we need to skip returning grpc error and instead return some meaningful error
cc @nixpanic any suggestions on how we can improvise the error?

[nixpanic]

okay, missed it, it seems we need to skip returning grpc error and instead return some meaningful error

gRPC functions should return a gRPC error witch codes.* as a status and a message. These are sent over the gRPC protocol back to the caller. The message that is part of the gRPC error should contain as many details as posssible, but user understandable. In the end, these should land in a .Status entry.

[nixpanic]

don't forget to include the original error too

[yati1998]

I dont think this change is required as parent existence check it anyways verified.
Closing this PR