IB/core: add support to create a unsafe global rkey to ib_create_pd

Instead of exposing ib_get_dma_mr to ULPs and letting them use it more or
less unchecked, this moves the capability of creating a global rkey into
the RDMA core, where it can be easily audited.  It also prints a warning
everytime this feature is used as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index ba6be06..8df608e 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -309,7 +309,7 @@
 	if (ret)
 		goto out;
 
-	device->pd = ib_alloc_pd(ib_dev);
+	device->pd = ib_alloc_pd(ib_dev, 0);
 	if (IS_ERR(device->pd)) {
 		ret = PTR_ERR(device->pd);
 		isert_err("failed to allocate pd, device %p, ret=%d\n",