NLM: have server-side RPC clients default to soft RPC tasks

Now that it no longer does an RPC ping, lockd always ends up queueing
an RPC task for the GRANT_MSG callback. But, it also requeues the block
for later attempts. Since these are hard RPC tasks, if the client we're
calling back goes unresponsive the GRANT_MSG callbacks can stack up in
the RPC queue.

Fix this by making server-side RPC clients default to soft RPC tasks.
lockd requeues the block anyway, so this should be OK.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/lockd/host.c

@@ -243,11 +243,18 @@ nlm_bind_host(struct nlm_host *host)
 			.program	= &nlm_program,
 			.version	= host->h_version,
 			.authflavor	= RPC_AUTH_UNIX,
-			.flags		= (RPC_CLNT_CREATE_HARDRTRY |
-					   RPC_CLNT_CREATE_NOPING |
+			.flags		= (RPC_CLNT_CREATE_NOPING |
 					   RPC_CLNT_CREATE_AUTOBIND),
 		};
 
+		/*
+		 * lockd retries server side blocks automatically so we want
+		 * those to be soft RPC calls. Client side calls need to be
+		 * hard RPC tasks.
+		 */
+		if (!host->h_server)
+			args.flags |= RPC_CLNT_CREATE_HARDRTRY;
+
 		clnt = rpc_create(&args);
 		if (!IS_ERR(clnt))
 			host->h_rpcclnt = clnt;