[adding Jens]--- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1547,6 +1547,8 @@ static void __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id) if (ns->head->disk) { nvme_update_disk_info(ns->head->disk, ns, id); blk_queue_stack_limits(ns->head->disk->queue, ns->queue); + /* XXX: multipath device does not support polling for now... */ + blk_queue_flag_clear(QUEUE_FLAG_POLL, ns->queue);I'd drop the XXX. But I think we actually have a block layer problem here. Currently stacking devices will just pass through REQ_HIPRI, despite none of them supporting any polling for it.
Yea... forgot there are other stack devices...
So we need to make sure in the block layer or I/O submitter that REQ_HIPRI is only set if QUEUE_FLAG_POLL is supported. I think it would also help if we rename it to REQ_POLL to make this more obvious.
It used to check for it, but was changed to look at nr_maps instead... So I think this is a regression...
