xprtrdma: Don't fall back to PHYSICAL memory registration

[ Queued for upstream v4.3 ]

PHYSICAL memory registration uses a single rkey for all of the
client's memory, thus is insecure. It is still useful in some cases
for testing.

Retain the ability to select PHYSICAL memory registration capability
via /proc/sys/sunrpc/rdma_memreg_strategy, but don't fall back to it
if the HCA does not support FRWR or FMR.

This means amso1100 no longer works out of the box with NFS/RDMA.
When using amso1100 HCAs, set the memreg_strategy sysctl to 6 before
performing NFS/RDMA mounts.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Devesh Sharma <devesh.sharma@avagotech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 234083560d0e2c5817d47775c17eceebdef23117..4e0919e7fbb156e34b09a55d0920a3351eaf981c 100644 (file)
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -619,7 +619,7 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
                if (!ia->ri_device->alloc_fmr) {
                        dprintk("RPC:       %s: MTHCAFMR registration "
                                "not supported by HCA\n", __func__);
-                       memreg = RPCRDMA_ALLPHYSICAL;
+                       goto out3;
                }
        }