Use blk_rq_nr_phys_segments() instead of blk_rq_payload_bytes() to check
if a command contains data to be mapped.  This fixes the case where
a struct request contains LBAs, but it has no payload, such as
Write Zeroes support.
Fixes: 6e02318eaea5 ("nvme: add support for the Write Zeroes command")
Reported-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Tested-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
        struct nvme_rdma_device *dev = queue->device;
        struct ib_device *ibdev = dev->dev;
 
-       if (!blk_rq_payload_bytes(rq))
+       if (!blk_rq_nr_phys_segments(rq))
                return;
 
        if (req->mr) {
 
        c->common.flags |= NVME_CMD_SGL_METABUF;
 
-       if (!blk_rq_payload_bytes(rq))
+       if (!blk_rq_nr_phys_segments(rq))
                return nvme_rdma_set_sg_null(c);
 
        req->sg_table.sgl = req->first_sgl;