[ewg] [PATCH] [for-2.6.33] rdma/cm: revert associating an RDMA device when binding to loopback

[Steve Wise]

This patch works.  It also backports cleanly to ofed-1.5.1/RH5.3.

Acked-by: Steve Wise <swise at opengridcomputing.com>

Steve.


Sean Hefty wrote:
> Revert the following change from commit
> 6f8372b69c3198e06cecb1df2cb9682d0c55e657:
>
>    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 openmpi depends on rdma_bind_addr NOT associating
> any RDMA device when binding to a loopback address.  Openmpi is
> being updated to correct this, but until a new openmpi 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 at intel.com>
> ---
> I believe this patch comes the closest to matching the behavior of
> rdma_bind_addr from 2.6.32 and before without completely reverting
> all support for loopback connections.  Loopback connections will
> work, but rdma_bind_addr will not automatically select an RDMA
> device if given a loopback address.
>
> Steve, can you test this with iwarp and openmpi, and ack it if it
> works for you?
>
>  drivers/infiniband/core/cma.c |    4 +---
>  1 files changed, 1 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
> index cc9b594..875e34e 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;
>
>
>
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