IB/mlx5: Fix unreg_umr to ignore the mkey state

Fix unreg_umr to ignore the mkey state and do not fail if was freed.  This
prevents a case that a user space application already changed the mkey
state to free and then the UMR operation will fail leaving the mkey in an
inappropriate state.

Link: https://lore.kernel.org/r/20190723065733.4899-3-leon@kernel.org
Cc: <stable@vger.kernel.org> # 3.19
Fixes: 968e78dd ("IB/mlx5: Enhance UMR support to allow partial page table update")
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -481,6 +481,7 @@ struct mlx5_umr_wr {
 	u64				length;
 	int				access_flags;
 	u32				mkey;
+	u8				ignore_free_state:1;
 };
 
 static inline const struct mlx5_umr_wr *umr_wr(const struct ib_send_wr *wr)

drivers/infiniband/hw/mlx5/mr.c

@@ -1372,10 +1372,10 @@ static int unreg_umr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
 	if (mdev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR)
 		return 0;
 
-	umrwr.wr.send_flags = MLX5_IB_SEND_UMR_DISABLE_MR |
-			      MLX5_IB_SEND_UMR_FAIL_IF_FREE;
+	umrwr.wr.send_flags = MLX5_IB_SEND_UMR_DISABLE_MR;
 	umrwr.wr.opcode = MLX5_IB_WR_UMR;
 	umrwr.mkey = mr->mmkey.key;
+	umrwr.ignore_free_state = 1;
 
 	return mlx5_ib_post_send_wait(dev, &umrwr);
 }

drivers/infiniband/hw/mlx5/qp.c

@@ -4295,10 +4295,14 @@ static int set_reg_umr_segment(struct mlx5_ib_dev *dev,
 
 	memset(umr, 0, sizeof(*umr));
 
+	if (!umrwr->ignore_free_state) {
 		if (wr->send_flags & MLX5_IB_SEND_UMR_FAIL_IF_FREE)
-		umr->flags = MLX5_UMR_CHECK_FREE; /* fail if free */
+			 /* fail if free */
+			umr->flags = MLX5_UMR_CHECK_FREE;
 		else
-		umr->flags = MLX5_UMR_CHECK_NOT_FREE; /* fail if not free */
+			/* fail if not free */
+			umr->flags = MLX5_UMR_CHECK_NOT_FREE;
+	}
 
 	umr->xlt_octowords = cpu_to_be16(get_xlt_octo(umrwr->xlt_size));
 	if (wr->send_flags & MLX5_IB_SEND_UMR_UPDATE_XLT) {