svn commit: r336542 - head/sys/rpc

[Rick Macklem]

Author: rmacklem
Date: Fri Jul 20 12:03:16 2018
New Revision: 336542
URL: https://svnweb.freebsd.org/changeset/base/336542

Log:
  Set SO_SNDTIMEO in the client side krpc when CLSET_TIMEOUT is done.
  
  During testing of the pNFS client, it was observed that an RPC could get
  stuck in sosend() for a very long time if the network connection to a DS
  had failed. This is fixed by setting SO_SNDTIMEO on the TCP socket.
  This is only done when CLSET_TIMEOUT is done and this is not done by any
  use of the krpc currently in the source tree, so there should be no effect
  on extant uses.
  A future patch will use CLSET_TIMEOUT for TCP connections to DSs.
  
  Reviewed by:	kib
  MFC after:	2 weeks
  Differential Revision:	https://reviews.freebsd.org/D16293

Modified:
  head/sys/rpc/clnt_rc.c

Modified: head/sys/rpc/clnt_rc.c
==============================================================================
--- head/sys/rpc/clnt_rc.c	Fri Jul 20 07:16:28 2018	(r336541)
+++ head/sys/rpc/clnt_rc.c	Fri Jul 20 12:03:16 2018	(r336542)
@@ -174,10 +174,26 @@ clnt_reconnect_connect(CLIENT *cl)
 		newclient = clnt_dg_create(so,
 		    (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
 		    rc->rc_sendsz, rc->rc_recvsz);
-	else
+	else {
+		/*
+		 * I do not believe a timeout of less than 1sec would make
+		 * sense here since short delays can occur when a server is
+		 * temporarily overloaded.
+		 */
+		if (rc->rc_timeout.tv_sec > 0 && rc->rc_timeout.tv_usec >= 0) {
+			error = so_setsockopt(so, SOL_SOCKET, SO_SNDTIMEO,
+			    &rc->rc_timeout, sizeof(struct timeval));
+			if (error != 0) {
+				stat = rpc_createerr.cf_stat = RPC_CANTSEND;
+				rpc_createerr.cf_error.re_errno = error;
+				td->td_ucred = oldcred;
+				goto out;
+			}
+		}
 		newclient = clnt_vc_create(so,
 		    (struct sockaddr *) &rc->rc_addr, rc->rc_prog, rc->rc_vers,
 		    rc->rc_sendsz, rc->rc_recvsz, rc->rc_intr);
+	}
 	td->td_ucred = oldcred;
 
 	if (!newclient) {