nvme-rdma: fix in-casule data send for chained sgls

We have only 2 inline sg entries and we allow 4 sg entries for the send
wr sge. Larger sgls entries will be chained. However when we build
in-capsule send wr sge, we iterate without taking into account that the
sgl may be chained and still fit in-capsule (which can happen if the sgl
is bigger than 2, but lower-equal to 4).

Fix in-capsule data mapping to correctly iterate chained sgls.

Fixes: 38e1800275d3 ("nvme-rdma: Avoid preallocating big SGL for data")
Reported-by: Walker, Benjamin <benjamin.walker@intel.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 37943dc..4697a94 100644 (file)
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1320,16 +1320,17 @@ static int nvme_rdma_map_sg_inline(struct nvme_rdma_queue *queue,
                int count)
 {
        struct nvme_sgl_desc *sg = &c->common.dptr.sgl;
-       struct scatterlist *sgl = req->data_sgl.sg_table.sgl;
        struct ib_sge *sge = &req->sge[1];
+       struct scatterlist *sgl;
        u32 len = 0;
        int i;
 
-       for (i = 0; i < count; i++, sgl++, sge++) {
+       for_each_sg(req->data_sgl.sg_table.sgl, sgl, count, i) {
                sge->addr = sg_dma_address(sgl);
                sge->length = sg_dma_len(sgl);
                sge->lkey = queue->device->pd->local_dma_lkey;
                len += sge->length;
+               sge++;
        }
 
        sg->addr = cpu_to_le64(queue->ctrl->ctrl.icdoff);