RDMA/cm: Revert association of an RDMA device when binding to loopback

Revert the following change from commit 6f8372b6 ("RDMA/cm: fix
loopback address support")

   The defined behavior of rdma_bind_addr is to associate an RDMA
   device with an rdma_cm_id, as long as the user specified a non-
   zero address.  (ie they weren't just trying to reserve a port)
   Currently, if the loopback address is passed to rdma_bind_addr,
   no device is associated with the rdma_cm_id.  Fix this.

It turns out that important apps such as Open MPI depend on
rdma_bind_addr() NOT associating any RDMA device when binding to a
loopback address.  Open MPI is being updated to deal with this, but at
least until a new Open MPI release is available, maintain the previous
behavior: allow rdma_bind_addr() to succeed, but do not bind to a
device.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 1 insertions, 3 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index cc9b5940fa97..875e34e0b235 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -2115,9 +2115,7 @@ int rdma_bind_addr(struct rdma_cm_id *id, struct sockaddr *addr)
         if (ret)
                 goto err1;
 
-        if (cma_loopback_addr(addr)) {
-                ret = cma_bind_loopback(id_priv);
-        } else if (!cma_zero_addr(addr)) {
+        if (!cma_any_addr(addr)) {
                 ret = rdma_translate_ip(addr, &id->route.addr.dev_addr);
                 if (ret)
                         goto err1;