ITS#10218 Disabling and re-enabling an asyncmeta database via cn=config leaks memory

Make sure asyncmeta frees the pending operations structures, resets all connections, frees connection structures and stops the timeout-loop.

servers/slapd/back-asyncmeta/back-asyncmeta.h

@@ -427,6 +427,7 @@ typedef struct a_metainfo_t {
 	a_metaconn_t          *mi_conns;
 
 	struct berval		mi_suffix;
+	volatile int          mi_disabled;
 } a_metainfo_t;
 
 typedef enum meta_op_type {
@@ -780,6 +781,9 @@ asyncmeta_db_has_mscs(a_metainfo_t *mi);
 void
 asyncmeta_target_free(a_metatarget_t *mt);
 
+void
+asyncmeta_back_clear_miconns(a_metainfo_t *mi);
+
 /* The the maximum time in seconds after a result has been received on a connection,
  * after which it can be reset if a sender error occurs. Should this be configurable? */
 #define META_BACK_RESULT_INTERVAL (2)

servers/slapd/back-asyncmeta/init.c

@@ -240,13 +240,13 @@ asyncmeta_back_db_open(
 	char msg[SLAP_TEXT_BUFLEN];
 	int		i;
 
+	mi->mi_disabled = 0;
 	if ( mi->mi_ntargets == 0 ) {
 
 		Debug( LDAP_DEBUG_ANY,
 			"asyncmeta_back_db_open: no targets defined\n" );
 	}
 
-	mi->mi_num_conns = 0;
 	for ( i = 0; i < mi->mi_ntargets; i++ ) {
 		a_metatarget_t	*mt = mi->mi_targets[ i ];
 		if ( asyncmeta_target_finish( mi, mt,
@@ -255,6 +255,7 @@ asyncmeta_back_db_open(
 		}
 	}
 
+	if ( mi->mi_conns == NULL ) {
 		mi->mi_num_conns = (mi->mi_max_target_conns == 0) ? META_BACK_CFG_MAX_TARGET_CONNS : mi->mi_max_target_conns;
 		assert(mi->mi_num_conns > 0);
 		mi->mi_conns = ch_calloc( mi->mi_num_conns, sizeof( a_metaconn_t ));
@@ -273,6 +274,7 @@ asyncmeta_back_db_open(
 			LDAP_STAILQ_INIT( &mc->mc_om_list );
 		}
 	
+
 		ber_dupbv ( &mi->mi_suffix, &be->be_suffix[0] );
 
 		if ( ( slapMode & SLAP_SERVER_MODE ) && mi->mi_ntargets > 0 ) {
@@ -281,6 +283,7 @@ asyncmeta_back_db_open(
 													asyncmeta_timeout_loop, mi, "asyncmeta_timeout_loop", mi->mi_suffix.bv_val );
 			ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
 		}
+	}
 	return 0;
 }
 
@@ -301,28 +304,26 @@ asyncmeta_back_conn_free(
 	free( mc );
 }
 
-static void
-asyncmeta_back_stop_miconns( a_metainfo_t *mi )
-{
-
-	/*Todo do any other mc cleanup here if necessary*/
-}
-
-static void
+void
 asyncmeta_back_clear_miconns( a_metainfo_t *mi )
 {
 	int i, j;
 	a_metaconn_t *mc;
+	if ( mi->mi_conns != NULL ) {
 		for (i = 0; i < mi->mi_num_conns; i++) {
 			mc = &mi->mi_conns[i];
-		/* todo clear the message queue */
 			for (j = 0; j < mi->mi_ntargets; j ++) {
 				asyncmeta_clear_one_msc(NULL, mc, j, 1, __FUNCTION__);
 			}
-		free(mc->mc_conns);
+
+			if ( mc->mc_conns )
+				free( mc->mc_conns );
 			ldap_pvt_thread_mutex_destroy( &mc->mc_om_mutex );
 		}
 		free(mi->mi_conns);
+	}
+	mi->mi_conns = NULL;
+	mi->mi_num_conns = 0;
 }
 
 void
@@ -392,6 +393,13 @@ asyncmeta_back_db_close(
 
 	if ( be->be_private ) {
 		mi = ( a_metainfo_t * )be->be_private;
+		mi->mi_disabled = 1;
+		/* there are no pending ops so we can free up the connections and stop the timeout loop
+		 * else timeout_loop will clear up the ops and connections and not reschedule */
+		if ( asyncmeta_db_has_pending_ops( mi ) == 0 ) {
+				ldap_pvt_thread_mutex_lock( &mi->mi_mc_mutex );
+				asyncmeta_back_clear_miconns(mi);
+				ldap_pvt_thread_mutex_unlock( &mi->mi_mc_mutex );
 				if ( mi->mi_task != NULL ) {
 					ldap_pvt_thread_mutex_lock( &slapd_rq.rq_mutex );
 					if ( ldap_pvt_runqueue_isrunning( &slapd_rq, mi->mi_task )) {
@@ -400,9 +408,7 @@ asyncmeta_back_db_close(
 					ldap_pvt_thread_mutex_unlock( &slapd_rq.rq_mutex );
 					mi->mi_task = NULL;
 				}
-		ldap_pvt_thread_mutex_lock( &mi->mi_mc_mutex );
-		asyncmeta_back_stop_miconns( mi );
-		ldap_pvt_thread_mutex_unlock( &mi->mi_mc_mutex );
+		}
 	}
 	return 0;
 }

servers/slapd/back-asyncmeta/meta_result.c

@@ -1487,6 +1487,11 @@ asyncmeta_op_handle_result(void *ctx, void *arg)
 	bm_context_t *bc;
 	void *oldctx;
 
+/* exit if the database is disabled, this will let timeout_loop
+ * do it's job faster */
+	if ( mc->mc_info->mi_disabled > 0 )
+		return NULL;
+
 	ldap_pvt_thread_mutex_lock( &mc->mc_om_mutex );
 	rc = ++mc->mc_active;
 	ldap_pvt_thread_mutex_unlock( &mc->mc_om_mutex );
@@ -1661,6 +1666,14 @@ void* asyncmeta_timeout_loop(void *ctx, void *arg)
 	LDAP_STAILQ_INIT( &timeout_list );
 
 	Debug( asyncmeta_debug, "asyncmeta_timeout_loop[%p] start at [%ld] \n", rtask, current_time );
+	if ( mi->mi_disabled > 0 && asyncmeta_db_has_pending_ops( mi ) == 0 ) {
+		Debug( asyncmeta_debug, "asyncmeta_timeout_loop[%p] database disabled, clearing connections [%ld] \n", rtask, current_time );
+		ldap_pvt_thread_mutex_lock( &mi->mi_mc_mutex );
+		asyncmeta_back_clear_miconns( mi );
+		mi->mi_task = NULL;
+		ldap_pvt_thread_mutex_unlock( &mi->mi_mc_mutex );
+		return NULL;
+	}
 	void *oldctx = slap_sl_mem_create(SLAP_SLAB_SIZE, SLAP_SLAB_STACK, ctx, 0);
 	for (i=0; i<mi->mi_num_conns; i++) {
 		a_metaconn_t * mc= &mi->mi_conns[i];
@@ -1671,6 +1684,10 @@ void* asyncmeta_timeout_loop(void *ctx, void *arg)
 				continue;
 			}
 
+			if (mi->mi_disabled > 0) {
+				bc->bc_invalid = 1;
+			}
+
 			if (bc->op->o_abandon ) {
 				Operation *op = bc->op;