[sheepdog] [PATCH] sheep: let outstanding IO req doesn't block confchg event

[Christoph Hellwig]

> -	if (is_vdi_obj(oid))
> -		flags &= ~O_DIRECT;
> +	if (iocb->epoch < sys_epoch()) {
> +		dprintf("%"PRIu32" sys %"PRIu32"\n", iocb->epoch, sys_epoch());
> +		return SD_RES_OLD_NODE_VER;
> +	} else {

Can you explain why we need the epoch check here in the changelog?
Also any reason it's down in farm instead of in store.c?

No need for the else here - after the return nothing else will be
executed.