[v3,1/5] IB/core: Make rdma_rw_ctx_init() initialize all used fields

Commit Message

Bart Van Assche July 19, 2016, 4:21 p.m. UTC

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 <[e-mail]>
Cc: <[e-mail]> #v4.7+
Cc: Christoph Hellwig <[e-mail]>
Cc: Sagi Grimberg <[e-mail]>
Cc: Steve Wise <[e-mail]>
Cc: Parav Pandit <[e-mail]>
Cc: Nicholas Bellinger <[e-mail]>
Cc: Laurence Oberman <[e-mail]>
---
 drivers/infiniband/core/rw.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

Comments

Christoph Hellwig July 21, 2016, 7:56 a.m. UTC | #1

Looks fine,

Reviewed-by: Christoph Hellwig <[e-mail]>
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Patch

diff --git a/drivers/infiniband/core/rw.c b/drivers/infiniband/core/rw.c
index 1eb9b12..1ad2baa 100644
--- 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;