diff -rubB owfs-3.2p2.orig/module/owserver/src/c/owserver.c owfs-3.2p2/module/owserver/src/c/owserver.c

--- owfs-3.2p2.orig/module/owserver/src/c/owserver.c	2020-09-23 10:58:40.000000000 +0300

+++ owfs-3.2p2/module/owserver/src/c/owserver.c	2021-01-21 14:26:36.643855596 +0300

@@ -36,6 +36,8 @@

 #include "owserver.h"

+pthread_mutex_t persistence_mutex ;

+

 /* --- Prototypes ------------ */

 static void SetupAntiloop(int argc, char **argv);

diff -rubB owfs-3.2p2.orig/module/owserver/src/include/owserver.h owfs-3.2p2/module/owserver/src/include/owserver.h

--- owfs-3.2p2.orig/module/owserver/src/include/owserver.h	2020-09-23 10:58:40.000000000 +0300

+++ owfs-3.2p2/module/owserver/src/include/owserver.h	2021-01-21 14:26:17.634796523 +0300

@@ -19,7 +19,7 @@

 #include "ow.h"

 #include "ow_connection.h"

-pthread_mutex_t persistence_mutex ;

+extern pthread_mutex_t persistence_mutex ;

 #define PERSISTENCELOCK    _MUTEX_LOCK(   persistence_mutex ) ;

 #define PERSISTENCEUNLOCK  _MUTEX_UNLOCK( persistence_mutex ) ;