Hi Matias, I've been looking over this and I really think it needs a fundamental rearchitecture still. The design of using a separate stacking block device and all kinds of private hooks does not look very maintainable. Here is my counter suggestion: - the stacking block device goes away - the nvm_target_type make_rq and prep_rq callbacks are combined into one and called from the nvme/null_blk ->queue_rq method early on to prepare the FTL state. The drivers that are LightNVM enabled reserve a pointer to it in their per request data, which the unprep_rq callback is called on durign I/O completion. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html