From d2e9d29b77c9eabb73ab859ccb0635e8c45a30a0 Mon Sep 17 00:00:00 2001
From: Nickolai Zeldovich <kolya@mit.edu>
Date: Fri, 5 Oct 2001 21:36:59 +0000
Subject: [PATCH] afsd-afsdb-shutdown-cleanly-20011005

make userspace afsdb handler shut down cleanly
---
 src/afs/afs_call.c    | 16 +++++++++++++++-
 src/afs/afs_cell.c    | 31 +++++++++++++++++++++++++++++--
 src/afs/afs_dcache.c  |  4 ++++
 src/afsd/afsd.c       |  5 +++++
 src/config/afs_args.h |  1 +
 5 files changed, 54 insertions(+), 3 deletions(-)

diff --git a/src/afs/afs_call.c b/src/afs/afs_call.c
index 1ac95bf80..71cea688b 100644
--- a/src/afs/afs_call.c
+++ b/src/afs/afs_call.c
@@ -609,8 +609,16 @@ long parm, parm2, parm3, parm4, parm5, parm6;
 	int cellLen = (sizeArg & 0xffff0000) >> 16;
 	afs_int32 *kmsg = afs_osi_Alloc(kmsgLen);
 	char *cellname = afs_osi_Alloc(cellLen);
+
 	AFS_COPYIN((afs_int32 *)parm3, kmsg, kmsgLen, code);
-	if (!code) code = afs_AfsdbHandler(cellname, cellLen, kmsg);
+	if (!code) {
+	    code = afs_AfsdbHandler(cellname, cellLen, kmsg);
+	    if (*cellname == 1) *cellname = 0;
+	    if (code == -2) {	/* Shutting down? */
+		*cellname = 1;
+		code = 0;
+	    }
+	}
 	if (!code) AFS_COPYOUT(cellname, (char *)parm2, cellLen, code);
 	afs_osi_Free(kmsg, kmsgLen);
 	afs_osi_Free(cellname, cellLen);
@@ -1201,6 +1209,12 @@ afs_shutdown()
 	afs_osi_Wakeup((char*)&afs_CacheTruncateDaemon);
 	afs_osi_Sleep(&afs_termState);
     }
+#ifdef AFS_AFSDB_ENV
+    afs_warn("AFSDB... ");
+    afs_StopAfsdb();
+    while (afs_termState == AFSOP_STOP_AFSDB)
+	afs_osi_Sleep(&afs_termState);
+#endif
 #if	defined(AFS_SUN5_ENV) || defined(RXK_LISTENER_ENV)
     afs_warn("RxEvent... ");
     /* cancel rx event deamon */
diff --git a/src/afs/afs_cell.c b/src/afs/afs_cell.c
index 82bf5a26d..2d8311059 100644
--- a/src/afs/afs_cell.c
+++ b/src/afs/afs_cell.c
@@ -57,6 +57,7 @@ static char afs_AfsdbLookupWait;
 
 char afs_AfsdbHandlerPresent = 0;
 char afs_AfsdbHandlerInuse = 0;
+char afs_AfsdbHandlerShutdown = 0;
 
 char *afs_AfsdbHandler_CellName;
 afs_int32 *afs_AfsdbHandler_CellHosts;
@@ -87,6 +88,16 @@ int afs_strcasecmp(s1, s2)
 
 
 #ifdef AFS_AFSDB_ENV
+void afs_StopAfsdb()
+{
+    if (afs_AfsdbHandlerPresent) {
+	afs_osi_Wakeup(&afs_AfsdbHandlerWait);
+    } else {
+	afs_AfsdbHandlerShutdown = 1;
+	afs_termState = AFSOP_STOP_RXEVENT;
+    }
+}
+
 int afs_AfsdbHandler(acellName, acellNameLen, kernelMsg)
     char *acellName;
     int acellNameLen;
@@ -94,6 +105,7 @@ int afs_AfsdbHandler(acellName, acellNameLen, kernelMsg)
 {
     /* afs_syscall_call() has already grabbed the global lock */
 
+    if (afs_AfsdbHandlerShutdown) return -2;
     afs_AfsdbHandlerPresent = 1;
 
     if (afs_AfsdbHandler_ReqPending) {
@@ -117,9 +129,21 @@ int afs_AfsdbHandler(acellName, acellNameLen, kernelMsg)
     }
 
     /* Wait for a request */
-    while (afs_AfsdbHandler_ReqPending == 0)
+    while (afs_AfsdbHandler_ReqPending == 0 && afs_termState != AFSOP_STOP_AFSDB)
 	afs_osi_Sleep(&afs_AfsdbHandlerWait);
 
+    /* Check if we're shutting down */
+    if (afs_termState == AFSOP_STOP_AFSDB) {
+	/* Inform anyone waiting for us that we're going away */
+	afs_AfsdbHandlerShutdown = 1;
+	afs_AfsdbHandlerPresent = 0;
+	afs_osi_Wakeup(&afs_AfsdbLookupWait);
+
+	afs_termState = AFSOP_STOP_RXEVENT;
+	afs_osi_Wakeup(&afs_termState);
+	return -2;
+    }
+
     /* Copy the requested cell name into the request buffer */
     strncpy(acellName, afs_AfsdbHandler_CellName, acellNameLen);
 
@@ -139,6 +163,9 @@ int afs_GetCellHostsFromDns(acellName, acellHosts, timeout)
 
     if (!afs_AfsdbHandlerPresent) return ENOENT;
 
+    /* Initialize host list to empty in case the handler is gone */
+    *acellHosts = 0;
+
     if (!ISAFS_GLOCK()) {
 	grab_glock = 1;
 	AFS_GLOCK();
@@ -160,7 +187,7 @@ int afs_GetCellHostsFromDns(acellName, acellHosts, timeout)
     afs_osi_Wakeup(&afs_AfsdbHandlerWait);
 
     /* Wait for the handler to get back to us with the reply */
-    while (!afs_AfsdbHandler_Completed)
+    while (afs_AfsdbHandlerPresent && !afs_AfsdbHandler_Completed)
 	afs_osi_Sleep(&afs_AfsdbLookupWait);
 
     /* Release the AFSDB handler and wake up others waiting for it */
diff --git a/src/afs/afs_dcache.c b/src/afs/afs_dcache.c
index f2c0459b9..ee28e5dd1 100644
--- a/src/afs/afs_dcache.c
+++ b/src/afs/afs_dcache.c
@@ -294,7 +294,11 @@ void afs_CacheTruncateDaemon() {
 	    afs_stats_AddTo(CTD_stats.CTD_sleepTime, CTD_tmpTime);
 	}
 	if (afs_termState == AFSOP_STOP_TRUNCDAEMON) {
+#ifdef AFS_AFSDB_ENV
+	    afs_termState = AFSOP_STOP_AFSDB;
+#else
 	    afs_termState = AFSOP_STOP_RXEVENT;
+#endif
 	    afs_osi_Wakeup(&afs_termState);
 	    break;
 	}
diff --git a/src/afsd/afsd.c b/src/afsd/afsd.c
index 3edd97e83..7ff32b8e8 100644
--- a/src/afsd/afsd.c
+++ b/src/afsd/afsd.c
@@ -1067,6 +1067,9 @@ static AfsdbLookupHandler()
 	    continue;
 	}
 
+	if (*acellName == 1)	/* Shutting down */
+	    break;
+
 	code = afsconf_GetAfsdbInfo(acellName, 0, &acellInfo);
 	if (code) {
 	    kernelMsg[0] = 0;
@@ -1081,6 +1084,8 @@ static AfsdbLookupHandler()
 		kernelMsg[i+2] = acellInfo.hostAddr[i].sin_addr.s_addr;
 	}    
     }
+
+    exit(1);
 }
 #endif
 
diff --git a/src/config/afs_args.h b/src/config/afs_args.h
index 51427adee..1c76a9e29 100644
--- a/src/config/afs_args.h
+++ b/src/config/afs_args.h
@@ -105,6 +105,7 @@
 /* #define AFSOP_STOP_RXEVENT   214     defined in osi.h	      */
 /* #define AFSOP_STOP_COMPLETE     215  defined in osi.h	      */
 /* #define AFSOP_STOP_RXK_LISTENER   217     defined in osi.h	      */
+#define AFSOP_STOP_AFSDB	218	/* Stop AFSDB handler */
 
 /* Main afs syscall entry; this number may vary per system (i.e. defined in afs/param.h) */
 #ifndef	AFS_SYSCALL
-- 
2.39.5