xprtrdma: Don't require LOCAL_DMA_LKEY support for fastreg

There is no need to require LOCAL_DMA_LKEY support as the
PD allocation makes sure that there is a local_dma_lkey. Also
correctly set a return value in error path.

This caused a NULL pointer dereference in mlx5 which removed
the support for LOCAL_DMA_LKEY.

Fixes: bb6c96d72879 ("xprtrdma: Replace global lkey with lkey local to PD")
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index eb081ad05e33..81e8d31f3abc 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -543,11 +543,8 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
         }
 
         if (memreg == RPCRDMA_FRMR) {
-                /* Requires both frmr reg and local dma lkey */
-                if (((devattr->device_cap_flags &
-                     (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) !=
-                    (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) ||
-                      (devattr->max_fast_reg_page_list_len == 0)) {
+                if (!(devattr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) ||
+                    (devattr->max_fast_reg_page_list_len == 0)) {
                         dprintk("RPC:       %s: FRMR registration "
                                 "not supported by HCA\n", __func__);
                         memreg = RPCRDMA_MTHCAFMR;
@@ -557,6 +554,7 @@ 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__);
+                        rc = -EINVAL;
                         goto out3;
                 }
         }