From a8b0936e63eeb7160e5dcb478235f03eee2c7b62 Mon Sep 17 00:00:00 2001
From: Nickolai Zeldovich <kolya@mit.edu>
Date: Thu, 22 Aug 2002 02:47:44 +0000
Subject: [PATCH] Always verify that the client is fully reachable before
 talking to it, in the fileserver.  This prevents some additional lossage
 cases with poorly-connected clients.

Disable same feature for other Rx services, since they don't
need to incur extra RTT delay.


(cherry picked from commit feb689396ccc39f304db05cb69dc8db3506de921)
---
 src/rx/rx.c       | 7 ++-----
 src/rx/rx.h       | 4 ++++
 src/viced/viced.c | 1 +
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/rx/rx.c b/src/rx/rx.c
index 7a8243d85..72ed2f01e 100644
--- a/src/rx/rx.c
+++ b/src/rx/rx.c
@@ -1248,6 +1248,7 @@ rx_NewService(port, serviceId, serviceName, securityObjects,
 	    service->idleDeadTime = 60;
 	    service->connDeadTime = rx_connDeadTime;
 	    service->executeRequestProc = serviceProc;
+	    service->checkReach = 0;
 	    rx_services[i] = service;	/* not visible until now */
 	    AFS_RXGUNLOCK();
 	    USERPRI;
@@ -2919,12 +2920,8 @@ static int rxi_CheckConnReach(conn, call)
     struct rx_peer *peer = conn->peer;
     afs_uint32 now, lastReach;
 
-    MUTEX_ENTER(&rx_serverPool_lock);
-    if (service->nRequestsRunning <= service->maxProcs/2) {
-	MUTEX_EXIT(&rx_serverPool_lock);
+    if (service->checkReach == 0)
 	return 0;
-    }
-    MUTEX_EXIT(&rx_serverPool_lock);
 
     now = clock_Sec();
     MUTEX_ENTER(&peer->peer_lock);
diff --git a/src/rx/rx.h b/src/rx/rx.h
index b33056522..8cadf0b7c 100644
--- a/src/rx/rx.h
+++ b/src/rx/rx.h
@@ -204,6 +204,9 @@ int ntoh_syserr_conv(int error);
 /* Set the connection dead time for any connections created for this service (server only) */
 #define rx_SetServiceDeadTime(service, seconds) ((service)->secondsUntilDead = (seconds))
 
+/* Enable or disable asymmetric client checking for a service */
+#define rx_SetCheckReach(service, x) ((service)->checkReach = (x))
+
 /* Set connection dead time, for a specific client or server connection */
 extern void rx_SetConnDeadTime();
 
@@ -346,6 +349,7 @@ struct rx_service {
     u_short minProcs;		    /* Minimum # of requests guaranteed executable simultaneously */
     u_short connDeadTime;		    /* Seconds until a client of this service will be declared dead, if it is not responding */
     u_short idleDeadTime;		    /* Time a server will wait for I/O to start up again */
+    u_char checkReach;		    /* Check for asymmetric clients? */
 };
 
 #endif /* KDUMP_RX_LOCK */
diff --git a/src/viced/viced.c b/src/viced/viced.c
index d2c8ef1d7..ec2541093 100644
--- a/src/viced/viced.c
+++ b/src/viced/viced.c
@@ -488,6 +488,7 @@ main(argc, argv)
     rx_SetDestroyConnProc(tservice, (char (*)()) h_FreeConnection);
     rx_SetMinProcs(tservice, 3);
     rx_SetMaxProcs(tservice, lwps);
+    rx_SetCheckReach(tservice, 1);
 
     tservice = rx_NewService(0,  RX_STATS_SERVICE_ID, "rpcstats", sc, 4, RXSTATS_ExecuteRequest);
     if (!tservice) {
-- 
2.39.5