drbd/rely-on-sb-handlers.patch

diff -Naur drbd-9.0.15+git.c46d2790.orig/drbd/drbd_state.c drbd-9.0.15+git.c46d2790/drbd/drbd_state.c
--- drbd-9.0.15+git.c46d2790.orig/drbd/drbd_state.c	2019-01-10 13:10:28.152414247 +0800
+++ drbd-9.0.15+git.c46d2790/drbd/drbd_state.c	2019-01-10 13:10:38.140407675 +0800
@@ -251,6 +251,27 @@
 	return rv;
 }
 
+static bool is_sb_handlers_configured(struct drbd_connection *connection)
+{
+   bool configured = false;
+
+    enum drbd_after_sb_p after_sb_0p = -1;
+    enum drbd_after_sb_p after_sb_1p = -1;
+    enum drbd_after_sb_p after_sb_2p = -1;
+
+    after_sb_0p = rcu_dereference(connection->transport.net_conf)->after_sb_0p;
+    after_sb_1p = rcu_dereference(connection->transport.net_conf)->after_sb_1p;
+    after_sb_2p = rcu_dereference(connection->transport.net_conf)->after_sb_2p;
+
+   if (after_sb_2p != 0 || after_sb_0p != 0 || after_sb_1p != 0) {
+       drbd_info(connection, "Split-brain handler configured, rely on it.\n");
+       configured = true;
+   }
+
+   return configured;
+}
+
+
 bool resource_is_suspended(struct drbd_resource *resource, enum which_state which)
 {
 	bool rv = resource->susp_user[which] || resource->susp_nod[which];
@@ -1465,7 +1486,8 @@
 			if (!nc || nc->two_primaries)
 				continue;
 			if (connection->peer_role[NEW] == R_PRIMARY)
-				return SS_TWO_PRIMARIES;
+				if (!is_sb_handlers_configured(connection))
+					return SS_TWO_PRIMARIES;
 		}
 	}
 
@@ -1500,10 +1522,10 @@
 		nc = rcu_dereference(connection->transport.net_conf);
 		two_primaries = nc ? nc->two_primaries : false;
 		if (peer_role[NEW] == R_PRIMARY && peer_role[OLD] != R_PRIMARY && !two_primaries) {
-			if (role[NOW] == R_PRIMARY)
+			if (role[NOW] == R_PRIMARY && !is_sb_handlers_configured(connection))
 				return SS_TWO_PRIMARIES;
 			idr_for_each_entry(&resource->devices, device, vnr) {
-				if (device->open_ro_cnt)
+				if (device->open_ro_cnt && !is_sb_handlers_configured(connection))
 					return SS_PRIMARY_READER;
 			}
 		}
@@ -3785,8 +3807,10 @@
 		mask = NODE_MASK(connection->peer_node_id);
 		if ((resource->twopc_reply.primary_nodes & mask) &&
 		    !(connection->transport.net_conf->two_primaries)) {
-			rv = SS_TWO_PRIMARIES;
-			break;
+			if (!is_sb_handlers_configured(connection)){
+				rv = SS_TWO_PRIMARIES;
+				break;
+			}
 		}
 	}
 	rcu_read_unlock();
@@ -3829,10 +3853,13 @@
 			rcu_read_lock();
 			nc = rcu_dereference(connection->transport.net_conf);
 			two_primaries = nc ? nc->two_primaries : false;
-			rcu_read_unlock();
 
-			if (!two_primaries)
+			if (!two_primaries && !is_sb_handlers_configured(connection)) {
+				rcu_read_unlock();
 				return SS_TWO_PRIMARIES;
+			}
+
+			rcu_read_unlock();
 		}
 
 		return SS_SUCCESS;
@@ -3859,8 +3886,10 @@
 		nc = rcu_dereference(connection->transport.net_conf);
 		if (!nc->two_primaries &&
 		    NODE_MASK(connection->peer_node_id) & reply->primary_nodes) {
-			rv = SS_PRIMARY_READER;
-			break;
+			if (!is_sb_handlers_configured(connection)){
+				rv = SS_PRIMARY_READER;
+				break;
+			}
 		}
 	}
 	rcu_read_unlock();