[PATCH 4.9 020/164] mlx5: Fix mlx5_ib_map_mr_sg mr length

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sagi Grimberg <sagi@xxxxxxxxxxx>

commit 0a49f2c31c3efbeb0de3e4b5598764887f629be2 upstream.

In case we got an initial sg_offset, we need to
account for it in the mr length.

Fixes: ff2ba9936591 ("IB/core: Add passing an offset into the SG to ib_map_mr_sg")
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Tested-by: Israel Rukshin <israelr@xxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/infiniband/hw/mlx5/mr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1828,7 +1828,7 @@ mlx5_ib_sg_to_klms(struct mlx5_ib_mr *mr
 		klms[i].va = cpu_to_be64(sg_dma_address(sg) + sg_offset);
 		klms[i].bcount = cpu_to_be32(sg_dma_len(sg) - sg_offset);
 		klms[i].key = cpu_to_be32(lkey);
-		mr->ibmr.length += sg_dma_len(sg);
+		mr->ibmr.length += sg_dma_len(sg) - sg_offset;
 
 		sg_offset = 0;
 	}