IB/core: Make rdma_rw_ctx_init() initialize all used fields

Some but not all callers of rdma_rw_ctx_init() zero-initialize
struct rdma_rw_ctx. Hence make rdma_rw_ctx_init() initialize all
work request fields that will be read by ib_post_send().

Fixes: a060b5629ab0 ("IB/core: generic RDMA READ/WRITE API")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Cc: Parav Pandit <pandit.parav@gmail.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: <stable@vger.kernel.org> #v4.7+
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c
index 1eb9b12..1ad2baa 100644 (file)
--- a/drivers/infiniband/core/rw.c
+++ b/drivers/infiniband/core/rw.c
@@ -71,6 +71,7 @@ static inline u32 rdma_rw_fr_page_list_len(struct ib_device *dev)
        return min_t(u32, dev->attrs.max_fast_reg_page_list_len, 256);
 }
 
+/* Caller must have zero-initialized *reg. */
 static int rdma_rw_init_one_mr(struct ib_qp *qp, u8 port_num,
                struct rdma_rw_reg_ctx *reg, struct scatterlist *sg,
                u32 sg_cnt, u32 offset)
@@ -114,6 +115,7 @@ static int rdma_rw_init_mr_wrs(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                u8 port_num, struct scatterlist *sg, u32 sg_cnt, u32 offset,
                u64 remote_addr, u32 rkey, enum dma_data_direction dir)
 {
+       struct rdma_rw_reg_ctx *prev = NULL;
        u32 pages_per_mr = rdma_rw_fr_page_list_len(qp->pd->device);
        int i, j, ret = 0, count = 0;
 
@@ -125,7 +127,6 @@ static int rdma_rw_init_mr_wrs(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
        }
 
        for (i = 0; i < ctx->nr_ops; i++) {
-               struct rdma_rw_reg_ctx *prev = i ? &ctx->reg[i - 1] : NULL;
                struct rdma_rw_reg_ctx *reg = &ctx->reg[i];
                u32 nents = min(sg_cnt, pages_per_mr);
 
@@ -162,9 +163,13 @@ static int rdma_rw_init_mr_wrs(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                sg_cnt -= nents;
                for (j = 0; j < nents; j++)
                        sg = sg_next(sg);
+               prev = reg;
                offset = 0;
        }
 
+       if (prev)
+               prev->wr.wr.next = NULL;
+
        ctx->type = RDMA_RW_MR;
        return count;
 
@@ -205,11 +210,10 @@ static int rdma_rw_init_map_wrs(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                        rdma_wr->wr.opcode = IB_WR_RDMA_READ;
                rdma_wr->remote_addr = remote_addr + total_len;
                rdma_wr->rkey = rkey;
+               rdma_wr->wr.num_sge = nr_sge;
                rdma_wr->wr.sg_list = sge;
 
                for (j = 0; j < nr_sge; j++, sg = sg_next(sg)) {
-                       rdma_wr->wr.num_sge++;
-
                        sge->addr = ib_sg_dma_address(dev, sg) + offset;
                        sge->length = ib_sg_dma_len(dev, sg) - offset;
                        sge->lkey = qp->pd->local_dma_lkey;
@@ -220,8 +224,8 @@ static int rdma_rw_init_map_wrs(struct rdma_rw_ctx *ctx, struct ib_qp *qp,
                        offset = 0;
                }
 
-               if (i + 1 < ctx->nr_ops)
-                       rdma_wr->wr.next = &ctx->map.wrs[i + 1].wr;
+               rdma_wr->wr.next = i + 1 < ctx->nr_ops ?
+                       &ctx->map.wrs[i + 1].wr : NULL;
        }
 
        ctx->type = RDMA_RW_MULTI_WR;