NFS: load the rpc/rdma transport module automatically

When mounting an NFS/RDMA server with the "-o proto=rdma" or
"-o rdma" options, attempt to dynamically load the necessary
"xprtrdma" client transport module. Doing so improves usability,
while avoiding a static module dependency and any unnecesary
resources.

Signed-off-by: Tom Talpey <tmtalpey@gmail.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index d6686f4..0942fcb 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1018,6 +1018,7 @@ static int nfs_parse_mount_options(char *raw,
                case Opt_rdma:
                        mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
                        mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
+                       xprt_load_transport(p);
                        break;
                case Opt_acl:
                        mnt->flags &= ~NFS_MOUNT_NOACL;
@@ -1205,12 +1206,14 @@ static int nfs_parse_mount_options(char *raw,
                                /* vector side protocols to TCP */
                                mnt->flags |= NFS_MOUNT_TCP;
                                mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
+                               xprt_load_transport(string);
                                break;
                        default:
                                errors++;
                                dfprintk(MOUNT, "NFS:   unrecognized "
                                                "transport protocol\n");
                        }
+                       kfree(string);
                        break;
                case Opt_mountproto:
                        string = match_strdup(args);
@@ -1218,7 +1221,6 @@ static int nfs_parse_mount_options(char *raw,
                                goto out_nomem;
                        token = match_token(string,
                                            nfs_xprt_protocol_tokens, args);
-                       kfree(string);
 
                        switch (token) {
                        case Opt_xprt_udp: