RDMA/mlx5: Do not allow rereg of a ODP MR

This code is completely broken, the umem of a ODP MR simply cannot be
discarded without a lot more locking, nor can an ODP mkey be blithely
destroyed via destroy_mkey().

Fixes: 6aec21f6a832 ("IB/mlx5: Page faults handling infrastructure")
Link: https://lore.kernel.org/r/20191001153821.23621-2-jgg@ziepe.ca
Reviewed-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index 1eff031ef04842f06ab4d088b04a610b9388aa1b..e7f840f306e46acd6fc7be059294ef17ce602908 100644 (file)
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1441,6 +1441,9 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
        if (!mr->umem)
                return -EINVAL;
 
+       if (is_odp_mr(mr))
+               return -EOPNOTSUPP;
+
        if (flags & IB_MR_REREG_TRANS) {
                addr = virt_addr;
                len = length;
@@ -1486,8 +1489,6 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
                }
 
                mr->allocated_from_cache = 0;
-               if (IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING))
-                       mr->live = 1;
        } else {
                /*
                 * Send a UMR WQE
@@ -1516,7 +1517,6 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
 
        set_mr_fields(dev, mr, npages, len, access_flags);
 
-       update_odp_mr(mr);
        return 0;
 
 err: