On Mon, Mar 25, 2019 at 07:03:23PM -0700, Sagi Grimberg wrote: > > > > The scatterlist in the nvme target is always allocated by the nvmet > > > code itself an thus never contains multi-page sg list entries. > > > > I am wondering if it is true. > > > > Not look at other target code yet, however seems it isn't true for loop, > > see the following code in nvme_loop_queue_rq(): > > > > iod->req.sg = iod->sg_table.sgl; > > iod->req.sg_cnt = blk_rq_map_sg(req->q, req, iod->sg_table.sgl); > > iod->req.transfer_len = blk_rq_payload_bytes(req); > > > > And it has been triggered by nvme/011 in Yi's test. > > Yes, loop is an exception in this case. Thanks for the clarification! Another candidate fix is to set nvmet-loop's queue segment boundary mask as PAGE_SIZE - 1. Also there is the same issue for block device backed target. If no one objects, I'd like to take the approach of adjusting segment boundary mask. Thanks, Ming
