glusterfsd: To support volfile-server-transport type "unix"

glusterfsd fails if the glusterd is bind to specific-IP address.
This patch helps glusterfsd to get the volfile using Unix domain socket.
glusterfs -s <unix socket path> --volfile-server-transport unix
          --volfile-id <volume-name> <mount-point>
The patch checks if the volfile-server-transport is of type "unix",
If It is then uses rpc_transport_unix_options_build to get the volfile.

Change-Id: I81b881e7ac5a3a4f2ac83c789c385cf547f0d53e
BUG: 1279484
Signed-off-by: Mohamed Ashiq <mliyazud@redhat.com>
Signed-off-by: Humble Devassy Chirammal <hchiramm@redhat.com>
Reviewed-on: http://review.gluster.org/12556
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

glusterfsd/src/glusterfsd-mgmt.c

@@ -2101,18 +2101,22 @@ glusterfs_mgmt_init (glusterfs_ctx_t *ctx)
         char                    *host = NULL;
 
         cmd_args = &ctx->cmd_args;
+        GF_VALIDATE_OR_GOTO (THIS->name, cmd_args->volfile_server, out);
 
         if (ctx->mgmt)
                 return 0;
 
         if (cmd_args->volfile_server_port)
                 port = cmd_args->volfile_server_port;
 
-        host = "localhost";
-        if (cmd_args->volfile_server)
-                host = cmd_args->volfile_server;
+        host = cmd_args->volfile_server;
 
-        ret = rpc_transport_inet_options_build (&options, host, port);
+        if (cmd_args->volfile_server_transport &&
+            !strcmp (cmd_args->volfile_server_transport, "unix")) {
+                ret = rpc_transport_unix_options_build (&options, host, 0);
+        } else {
+                ret = rpc_transport_inet_options_build (&options, host, port);
+        }
         if (ret)
                 goto out;
 

glusterfsd/src/glusterfsd.c

@@ -96,8 +96,8 @@ static error_t parse_opts (int32_t key, char *arg, struct argp_state *_state);
 static struct argp_option gf_options[] = {
         {0, 0, 0, 0, "Basic options:"},
         {"volfile-server", ARGP_VOLFILE_SERVER_KEY, "SERVER", 0,
-         "Server to get the volume file from.  This option overrides "
-         "--volfile option"},
+         "Server to get the volume file from. Unix domain socket path when "
+         "transport type 'unix'. This option overrides --volfile option"},
         {"volfile", ARGP_VOLUME_FILE_KEY, "VOLFILE", 0,
          "File to use as VOLUME_FILE"},
         {"spec-file", ARGP_VOLUME_FILE_KEY, "VOLFILE", OPTION_HIDDEN,