From: Jack Wang <jinpu.wang@xxxxxxxxx> When iommu is enabled, we hit warnings like this: WARNING: at rtrs/rtrs.c:178 rtrs_iu_post_rdma_write_imm+0x9b/0x110 rtrs warn on one sge entry length is 0, which is unexpected. The problem is ib_dma_map_sg augments the SGL into a 'dma mapped SGL'. This process may change the number of entries and the lengths of each entry. Code that touches dma_address is iterating over the 'dma mapped SGL' and must use dma_nents which returned from ib_dma_map_sg(). So pass the count return from ib_dma_map_sg. Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality") Signed-off-by: Jack Wang <jinpu.wang@xxxxxxxxx> Reviewed-by: Aleksei Marov <aleksei.marov@xxxxxxxxx> --- drivers/infiniband/ulp/rtrs/rtrs-clt.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/infiniband/ulp/rtrs/rtrs-clt.c b/drivers/infiniband/ulp/rtrs/rtrs-clt.c index 5219bb10777a..5d0df186e937 100644 --- a/drivers/infiniband/ulp/rtrs/rtrs-clt.c +++ b/drivers/infiniband/ulp/rtrs/rtrs-clt.c @@ -1007,7 +1007,8 @@ rtrs_clt_get_copy_req(struct rtrs_clt_path *alive_path, static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con, struct rtrs_clt_io_req *req, struct rtrs_rbuf *rbuf, bool fr_en, - u32 size, u32 imm, struct ib_send_wr *wr, + u32 count, u32 size, u32 imm, + struct ib_send_wr *wr, struct ib_send_wr *tail) { struct rtrs_clt_path *clt_path = to_clt_path(con->c.path); @@ -1027,12 +1028,12 @@ static int rtrs_post_rdma_write_sg(struct rtrs_clt_con *con, num_sge = 2; ptail = tail; } else { - for_each_sg(req->sglist, sg, req->sg_cnt, i) { + for_each_sg(req->sglist, sg, count, i) { sge[i].addr = sg_dma_address(sg); sge[i].length = sg_dma_len(sg); sge[i].lkey = clt_path->s.dev->ib_pd->local_dma_lkey; } - num_sge = 1 + req->sg_cnt; + num_sge = 1 + count; } sge[i].addr = req->iu->dma_addr; sge[i].length = size; @@ -1145,7 +1146,7 @@ static int rtrs_clt_write_req(struct rtrs_clt_io_req *req) */ rtrs_clt_update_all_stats(req, WRITE); - ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, + ret = rtrs_post_rdma_write_sg(req->con, req, rbuf, fr_en, count, req->usr_len + sizeof(*msg), imm, wr, &inv_wr); if (ret) { -- 2.25.1