MDEV-12837: WSREP: BF lock wait long

This is 10.1 version where no merge error exists.

wsrep_on_check
        New check function. Galera can't be enabled
        if innodb-lock-schedule-algorithm=VATS.

innobase_kill_query
        In Galera async kill we could own lock mutex.

innobase_init
        If Variance-Aware-Transaction-Sheduling Algorithm (VATS) is
        used on Galera we refuse to start InnoDB.

Changed innodb-lock-schedule-algorithm as read-only parameter
as it was designed to be.

lock_rec_other_has_expl_req,
lock_rec_other_has_conflicting,
lock_rec_lock_slow
lock_table_other_has_incompatible
lock_rec_insert_check_and_lock

        Change pointer to conflicting lock to normal pointer as this
        pointer contents could be changed later.

11 files changed, 215 insertions, 107 deletions

diff --git a/mysql-test/suite/sys_vars/r/sysvars_innodb.result b/mysql-test/suite/sys_vars/r/sysvars_innodb.result
index acdbd007e6e..161f740dbfb 100644
--- a/mysql-test/suite/sys_vars/r/sysvars_innodb.result
+++ b/mysql-test/suite/sys_vars/r/sysvars_innodb.result
@@ -1347,7 +1347,7 @@ NUMERIC_MIN_VALUE	NULL
 NUMERIC_MAX_VALUE	NULL
 NUMERIC_BLOCK_SIZE	NULL
 ENUM_VALUE_LIST	fcfs,vats
-READ_ONLY	NO
+READ_ONLY	YES
 COMMAND_LINE_ARGUMENT	REQUIRED
 VARIABLE_NAME	INNODB_LOCK_WAIT_TIMEOUT
 SESSION_VALUE	50
diff --git a/mysql-test/suite/sys_vars/t/wsrep_on_basic.opt b/mysql-test/suite/sys_vars/t/wsrep_on_basic.opt
new file mode 100644
index 00000000000..aa1fb6cb155
--- /dev/null
+++ b/mysql-test/suite/sys_vars/t/wsrep_on_basic.opt
@@ -0,0 +1 @@
+--innodb-lock-schedule-algorithm=FCFS
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index 8eb3d35a96e..303633939c3 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -4895,7 +4895,8 @@ static Sys_var_mybool Sys_wsrep_on (
        "wsrep_on", "To enable wsrep replication ",
        SESSION_VAR(wsrep_on), 
        CMD_LINE(OPT_ARG), DEFAULT(FALSE),
-       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG,
+       ON_CHECK(wsrep_on_check),
        ON_UPDATE(wsrep_on_update));
 
 static Sys_var_charptr Sys_wsrep_start_position (
diff --git a/sql/wsrep_var.cc b/sql/wsrep_var.cc
index b21041eb0f8..ad1f4ec0eac 100644
--- a/sql/wsrep_var.cc
+++ b/sql/wsrep_var.cc
@@ -52,12 +52,28 @@ int wsrep_init_vars()
   return 0;
 }
 
+extern ulong innodb_lock_schedule_algorithm;
+
 bool wsrep_on_update (sys_var *self, THD* thd, enum_var_type var_type)
 {
   if (var_type == OPT_GLOBAL) {
     // FIXME: this variable probably should be changed only per session
     thd->variables.wsrep_on = global_system_variables.wsrep_on;
   }
+
+  return false;
+}
+
+bool wsrep_on_check(sys_var *self, THD* thd, set_var* var)
+{
+  bool new_wsrep_on= (bool)var->save_result.ulonglong_value;
+
+  if (new_wsrep_on && innodb_lock_schedule_algorithm != 0) {
+    my_message(ER_WRONG_ARGUMENTS, " WSREP (galera) can't be enabled "
+	    "if innodb_lock_schedule_algorithm=VATS. Please configure"
+	    " innodb_lock_schedule_algorithm=FCFS and restart.", MYF(0));
+    return true;
+  }
   return false;
 }
 
diff --git a/sql/wsrep_var.h b/sql/wsrep_var.h
index 7530fd98870..55eb2fbc501 100644
--- a/sql/wsrep_var.h
+++ b/sql/wsrep_var.h
@@ -41,7 +41,8 @@ int wsrep_init_vars();
 #define DEFAULT_ARGS (THD* thd, enum_var_type var_type)
 #define INIT_ARGS    (const char* opt)
 
-extern bool wsrep_causal_reads_update         UPDATE_ARGS;
+extern bool wsrep_causal_reads_update        UPDATE_ARGS;
+extern bool wsrep_on_check                   CHECK_ARGS;
 extern bool wsrep_on_update                  UPDATE_ARGS;
 extern bool wsrep_sync_wait_update           UPDATE_ARGS;
 extern bool wsrep_start_position_check       CHECK_ARGS;
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index 9a7258bc924..2d319439fad 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -3478,6 +3478,17 @@ innobase_init(
 		goto error;
 	}
 
+#ifdef WITH_WSREP
+	/* Currently, Galera does not support VATS lock schedule algorithm. */
+	if (innodb_lock_schedule_algorithm == INNODB_LOCK_SCHEDULE_ALGORITHM_VATS
+	    && global_system_variables.wsrep_on) {
+		/* Do not allow InnoDB startup with VATS and Galera */
+		sql_print_error("In Galera environment Variance-Aware-Transaction-Sheduling Algorithm"
+			" is not supported.");
+		goto error;
+	}
+#endif /* WITH_WSREP */
+
 #ifndef HAVE_LZ4
 	if (innodb_compression_algorithm == PAGE_LZ4_ALGORITHM) {
 		sql_print_error("InnoDB: innodb_compression_algorithm = %lu unsupported.\n"
@@ -4882,8 +4893,8 @@ innobase_kill_query(
 			wsrep_thd_is_BF(current_thd, FALSE),
 			lock_get_info(trx->lock.wait_lock).c_str());
 
-		if (!wsrep_thd_is_BF(trx->mysql_thd, FALSE) &&
-		    trx->abort_type == TRX_SERVER_ABORT) {
+		if (!wsrep_thd_is_BF(trx->mysql_thd, FALSE)
+		    && trx->abort_type == TRX_SERVER_ABORT) {
 			ut_ad(!lock_mutex_own());
 			lock_mutex_enter();
 		}
@@ -19234,7 +19245,7 @@ static MYSQL_SYSVAR_ULONG(doublewrite_batch_size, srv_doublewrite_batch_size,
 #endif /* defined UNIV_DEBUG || defined UNIV_PERF_DEBUG */
 
 static MYSQL_SYSVAR_ENUM(lock_schedule_algorithm, innodb_lock_schedule_algorithm,
-  PLUGIN_VAR_RQCMDARG,
+  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
   "The algorithm Innodb uses for deciding which locks to grant next when"
   " a lock is released. Possible values are"
   " FCFS"
diff --git a/storage/innobase/lock/lock0lock.cc b/storage/innobase/lock/lock0lock.cc
index 6b2c309e432..61385891b76 100644
--- a/storage/innobase/lock/lock0lock.cc
+++ b/storage/innobase/lock/lock0lock.cc
@@ -925,15 +925,21 @@ lock_reset_lock_and_trx_wait(
 
 		ib_logf(IB_LOG_LEVEL_INFO,
 			"Trx id " TRX_ID_FMT
-			" is waiting a lock in statement %s"
+			" is waiting a lock "
 			" for this trx id " TRX_ID_FMT
-			" and statement %s wait_lock %p",
+			" wait_lock %p",
 			lock->trx->id,
-			stmt ? stmt : "NULL",
 			trx_id,
-			stmt2 ? stmt2 : "NULL",
 			lock->trx->lock.wait_lock);
 
+		if (stmt) {
+			ib_logf(IB_LOG_LEVEL_INFO, " SQL1: %s\n", stmt);
+		}
+
+		if (stmt2) {
+			ib_logf(IB_LOG_LEVEL_INFO, " SQL2: %s\n", stmt2);
+		}
+
 		ut_ad(lock->trx->lock.wait_lock == lock);
 	}
 
@@ -1151,7 +1157,7 @@ lock_rec_has_to_wait(
 						type_mode, lock_is_on_supremum);
 					fprintf(stderr,
 						"conflicts states: my %d locked %d\n",
-						wsrep_thd_conflict_state(trx->mysql_thd, FALSE), 
+						wsrep_thd_conflict_state(trx->mysql_thd, FALSE),
 						wsrep_thd_conflict_state(lock2->trx->mysql_thd, FALSE) );
 					lock_rec_print(stderr, lock2);
 					if (for_locking) return FALSE;
@@ -1687,7 +1693,7 @@ lock_rec_discard(lock_t*	in_lock);
 Checks if some other transaction has a lock request in the queue.
 @return	lock or NULL */
 static
-const lock_t*
+lock_t*
 lock_rec_other_has_expl_req(
 /*========================*/
 	enum lock_mode		mode,	/*!< in: LOCK_S or LOCK_X */
@@ -1704,7 +1710,7 @@ lock_rec_other_has_expl_req(
 					requests by all transactions
 					are taken into account */
 {
-	const lock_t*	lock;
+	lock_t*	lock;
 
 	ut_ad(lock_mutex_own());
 	ut_ad(mode == LOCK_X || mode == LOCK_S);
@@ -1713,7 +1719,7 @@ lock_rec_other_has_expl_req(
 
 	for (lock = lock_rec_get_first(block, heap_no);
 	     lock != NULL;
-	     lock = lock_rec_get_next_const(heap_no, lock)) {
+	     lock = lock_rec_get_next(heap_no, lock)) {
 
 		if (lock->trx != trx
 		    && (gap
@@ -1800,7 +1806,7 @@ Checks if some other transaction has a conflicting explicit lock request
 in the queue, so that we have to wait.
 @return	lock or NULL */
 static
-const lock_t*
+lock_t*
 lock_rec_other_has_conflicting(
 /*===========================*/
 	enum lock_mode		mode,	/*!< in: LOCK_S or LOCK_X,
@@ -1812,7 +1818,7 @@ lock_rec_other_has_conflicting(
 	ulint			heap_no,/*!< in: heap number of the record */
 	const trx_t*		trx)	/*!< in: our transaction */
 {
-	const lock_t*		lock;
+	lock_t*		lock;
 	ibool			is_supremum;
 
 	ut_ad(lock_mutex_own());
@@ -1821,13 +1827,16 @@ lock_rec_other_has_conflicting(
 
 	for (lock = lock_rec_get_first(block, heap_no);
 	     lock != NULL;
-	     lock = lock_rec_get_next_const(heap_no, lock)) {
+	     lock = lock_rec_get_next(heap_no, lock)) {
 
 #ifdef WITH_WSREP
 		if (lock_rec_has_to_wait(TRUE, trx, mode, lock, is_supremum)) {
 			if (wsrep_on_trx(trx)) {
 				trx_mutex_enter(lock->trx);
-				wsrep_kill_victim(trx, lock);
+				/* Below function will roll back either trx
+				or lock->trx depending on priority of the
+				transaction. */
+				wsrep_kill_victim(const_cast<trx_t*>(trx), lock);
 				trx_mutex_exit(lock->trx);
 			}
 #else
@@ -2023,15 +2032,17 @@ wsrep_print_wait_locks(
 {
 	if (wsrep_debug &&  c_lock->trx->lock.wait_lock != c_lock) {
 		fprintf(stderr, "WSREP: c_lock != wait lock\n");
-		if (lock_get_type_low(c_lock) & LOCK_TABLE)
+		if (lock_get_type_low(c_lock) & LOCK_TABLE) {
 			lock_table_print(stderr, c_lock);
-		else
+		} else {
 			lock_rec_print(stderr, c_lock);
+		}
 
-		if (lock_get_type_low(c_lock->trx->lock.wait_lock) & LOCK_TABLE)
+		if (lock_get_type_low(c_lock->trx->lock.wait_lock) & LOCK_TABLE) {
 			lock_table_print(stderr, c_lock->trx->lock.wait_lock);
-		else
+		} else {
 			lock_rec_print(stderr, c_lock->trx->lock.wait_lock);
+		}
 	}
 }
 #endif /* WITH_WSREP */
@@ -2217,8 +2228,8 @@ lock_rec_create(
 			if (wsrep_debug) {
 				fprintf(
 					stderr,
-					"WSREP: c_lock canceled %llu\n",
-					(ulonglong) c_lock->trx->id);
+					"WSREP: c_lock canceled " TRX_ID_FMT "\n",
+					c_lock->trx->id);
 			}
 
 			/* have to bail out here to avoid lock_set_lock... */
@@ -2519,6 +2530,16 @@ lock_rec_enqueue_waiting(
 		err = DB_LOCK_WAIT;
 	}
 
+#ifdef WITH_WSREP
+	if (!lock_get_wait(lock) && wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
+		if (wsrep_debug) {
+			fprintf(stderr, "WSREP: BF thread got lock granted early, ID " TRX_ID_FMT
+				"\n",
+				lock->trx->id);
+		}
+		return(DB_SUCCESS);
+        }
+#endif /* WITH_WSREP */
 	// Move it only when it does not cause a deadlock.
 	if (err != DB_DEADLOCK
 		&& innodb_lock_schedule_algorithm
@@ -2814,7 +2835,7 @@ lock_rec_lock_slow(
 		/* The trx already has a strong enough lock on rec: do
 		nothing */
 #ifdef WITH_WSREP
-	} else if ((c_lock = (ib_lock_t*)lock_rec_other_has_conflicting(
+	} else if ((c_lock = lock_rec_other_has_conflicting(
                         static_cast<enum lock_mode>(mode),
                         block, heap_no, trx))) {
 #else
@@ -2946,6 +2967,15 @@ lock_rec_has_to_wait_in_queue(
 #ifdef WITH_WSREP
 			if (wsrep_thd_is_BF(wait_lock->trx->mysql_thd, FALSE) &&
 			    wsrep_thd_is_BF(lock->trx->mysql_thd, TRUE)) {
+				if (wsrep_debug) {
+					fprintf(stderr,
+						"BF-BF lock conflict " TRX_ID_FMT
+						" : " TRX_ID_FMT "\n",
+						wait_lock->trx->id,
+						lock->trx->id);
+					lock_rec_print(stderr, wait_lock);
+					lock_rec_print(stderr, lock);
+				}
 				/* don't wait for another BF lock */
 				continue;
 			}
@@ -3104,7 +3134,7 @@ lock_grant_and_move_on_page(
 			&& !lock_rec_has_to_wait_in_queue(lock)) {
 			
 			lock_grant(lock, false);
-			
+
 			if (previous != NULL) {
 				/* Move the lock to the head of the list. */
 				HASH_GET_NEXT(hash, previous) = HASH_GET_NEXT(hash, lock);
@@ -4978,8 +5008,8 @@ lock_table_create(
 			}
 
 			if (wsrep_debug) {
-				fprintf(stderr, "WSREP: c_lock canceled %llu\n",
-					(ulonglong) c_lock->trx->id);
+				fprintf(stderr, "WSREP: c_lock canceled " TRX_ID_FMT "\n",
+					c_lock->trx->id);
 			}
 		}
 		if (c_lock) {
@@ -5251,7 +5281,7 @@ Checks if other transactions have an incompatible mode lock request in
 the lock queue.
 @return	lock or NULL */
 UNIV_INLINE
-const lock_t*
+lock_t*
 lock_table_other_has_incompatible(
 /*==============================*/
 	const trx_t*		trx,	/*!< in: transaction, or NULL if all
@@ -5262,7 +5292,7 @@ lock_table_other_has_incompatible(
 	const dict_table_t*	table,	/*!< in: table */
 	enum lock_mode		mode)	/*!< in: lock mode */
 {
-	const lock_t*	lock;
+	lock_t*	lock;
 
 	ut_ad(lock_mutex_own());
 
@@ -5315,7 +5345,7 @@ lock_table(
 #endif
 	trx_t*		trx;
 	dberr_t		err;
-	const lock_t*	wait_for;
+	lock_t*		wait_for;
 
 	ut_ad(table != NULL);
 	ut_ad(thr != NULL);
@@ -5362,13 +5392,13 @@ lock_table(
 
 	if (wait_for != NULL) {
 #ifdef WITH_WSREP
-                err = lock_table_enqueue_waiting((ib_lock_t*)wait_for, mode | flags, table, thr);
+		err = lock_table_enqueue_waiting(wait_for, mode | flags, table, thr);
 #else
 		err = lock_table_enqueue_waiting(mode | flags, table, thr);
 #endif
 	} else {
 #ifdef WITH_WSREP
-	        lock_table_create(c_lock, table, mode | flags, trx);
+		lock_table_create(c_lock, table, mode | flags, trx);
 #else
 		lock_table_create(table, mode | flags, trx);
 #endif
@@ -7036,10 +7066,10 @@ lock_rec_insert_check_and_lock(
 	on the successor, which produced an unnecessary deadlock. */
 
 #ifdef WITH_WSREP
-	if ((c_lock = (ib_lock_t*)lock_rec_other_has_conflicting(
-		    static_cast<enum lock_mode>(
-                            LOCK_X | LOCK_GAP | LOCK_INSERT_INTENTION),
-		    block, next_rec_heap_no, trx))) {
+	if ((c_lock = lock_rec_other_has_conflicting(
+		static_cast<enum lock_mode>(
+			LOCK_X | LOCK_GAP | LOCK_INSERT_INTENTION),
+		block, next_rec_heap_no, trx))) {
 #else
 	if (lock_rec_other_has_conflicting(
 		    static_cast<enum lock_mode>(
@@ -7052,7 +7082,7 @@ lock_rec_insert_check_and_lock(
 
 #ifdef WITH_WSREP
 		err = lock_rec_enqueue_waiting(c_lock,
-                        LOCK_X | LOCK_GAP | LOCK_INSERT_INTENTION,
+			LOCK_X | LOCK_GAP | LOCK_INSERT_INTENTION,
 			block, next_rec_heap_no, index, thr);
 #else
 		err = lock_rec_enqueue_waiting(
diff --git a/storage/innobase/lock/lock0wait.cc b/storage/innobase/lock/lock0wait.cc
index ca9d05a4829..a0f557e18e5 100644
--- a/storage/innobase/lock/lock0wait.cc
+++ b/storage/innobase/lock/lock0wait.cc
@@ -191,22 +191,25 @@ lock_wait_table_reserve_slot(
 /*********************************************************************//**
 check if lock timeout was for priority thread, 
 as a side effect trigger lock monitor
+@param[in]    trx    transaction owning the lock
+@param[in]    locked true if trx and lock_sys_mutex is ownd
 @return        false for regular lock timeout */
-static ibool
+static
+bool
 wsrep_is_BF_lock_timeout(
-/*====================*/
-    trx_t* trx) /* in: trx to check for lock priority */
+	const trx_t*	trx,
+	bool		locked = true)
 {
-       if (wsrep_on_trx(trx) &&
-           wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
-               fprintf(stderr, "WSREP: BF lock wait long\n");
-                srv_print_innodb_monitor       = TRUE;
-                srv_print_innodb_lock_monitor  = TRUE;
-                os_event_set(srv_monitor_event);
-                return TRUE;
-       }
-       return FALSE;
- }
+	if (wsrep_on_trx(trx)
+	    && wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
+		fprintf(stderr, "WSREP: BF lock wait long for trx " TRX_ID_FMT "\n", trx->id);
+		srv_print_innodb_monitor	= TRUE;
+		srv_print_innodb_lock_monitor	= TRUE;
+		os_event_set(srv_monitor_event);
+		return true;
+	}
+	return false;
+}
 #endif /* WITH_WSREP */
 
 /***************************************************************//**
@@ -402,15 +405,15 @@ lock_wait_suspend_thread(
 	if (lock_wait_timeout < 100000000
 	    && wait_time > (double) lock_wait_timeout) {
 #ifdef WITH_WSREP
-                if (!wsrep_on_trx(trx) ||
-                    (!wsrep_is_BF_lock_timeout(trx) &&
-                     trx->error_state != DB_DEADLOCK)) {
+		if (!wsrep_on_trx(trx) ||
+		    (!wsrep_is_BF_lock_timeout(trx) &&
+		     trx->error_state != DB_DEADLOCK)) {
 #endif /* WITH_WSREP */
 
-		trx->error_state = DB_LOCK_WAIT_TIMEOUT;
+			trx->error_state = DB_LOCK_WAIT_TIMEOUT;
 
 #ifdef WITH_WSREP
-                }
+		}
 #endif /* WITH_WSREP */
 		MONITOR_INC(MONITOR_TIMEOUT);
 	}
diff --git a/storage/xtradb/handler/ha_innodb.cc b/storage/xtradb/handler/ha_innodb.cc
index 28e3b23b667..8487c5b2510 100644
--- a/storage/xtradb/handler/ha_innodb.cc
+++ b/storage/xtradb/handler/ha_innodb.cc
@@ -3934,6 +3934,17 @@ innobase_init(
 		}
 	}
 
+#ifdef WITH_WSREP
+	/* Currently, Galera does not support VATS lock schedule algorithm. */
+	if (innodb_lock_schedule_algorithm == INNODB_LOCK_SCHEDULE_ALGORITHM_VATS
+	    && global_system_variables.wsrep_on) {
+		/* Do not allow InnoDB startup with VATS and Galera */
+		sql_print_error("In Galera environment Variance-Aware-Transaction-Sheduling Algorithm"
+			" is not supported.");
+		goto error;
+	}
+#endif /* WITH_WSREP */
+
 #ifndef HAVE_LZ4
 	if (innodb_compression_algorithm == PAGE_LZ4_ALGORITHM) {
 		sql_print_error("InnoDB: innodb_compression_algorithm = %lu unsupported.\n"
@@ -5485,8 +5496,8 @@ innobase_kill_connection(
 			wsrep_thd_is_BF(current_thd, FALSE),
 			lock_get_info(trx->lock.wait_lock).c_str());
 
-		if (!wsrep_thd_is_BF(trx->mysql_thd, FALSE) &&
-		    trx->abort_type == TRX_SERVER_ABORT) {
+		if (!wsrep_thd_is_BF(trx->mysql_thd, FALSE)
+		    && trx->abort_type == TRX_SERVER_ABORT) {
 			ut_ad(!lock_mutex_own());
 			lock_mutex_enter();
 		}
@@ -20500,7 +20511,7 @@ static MYSQL_SYSVAR_ENUM(empty_free_list_algorithm,
   &innodb_empty_free_list_algorithm_typelib);
 
 static MYSQL_SYSVAR_ENUM(lock_schedule_algorithm, innodb_lock_schedule_algorithm,
-  PLUGIN_VAR_RQCMDARG,
+  PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
   "The algorithm Innodb uses for deciding which locks to grant next when"
   " a lock is released. Possible values are"
   " FCFS"
diff --git a/storage/xtradb/lock/lock0lock.cc b/storage/xtradb/lock/lock0lock.cc
index ddaeff69f10..20e3f5adeb7 100644
--- a/storage/xtradb/lock/lock0lock.cc
+++ b/storage/xtradb/lock/lock0lock.cc
@@ -937,14 +937,21 @@ lock_reset_lock_and_trx_wait(
 
 		ib_logf(IB_LOG_LEVEL_INFO,
 			"Trx id " TRX_ID_FMT
-			" is waiting a lock in statement %s"
+			" is waiting a lock "
 			" for this trx id " TRX_ID_FMT
-			" and statement %s wait_lock %p",
+			" wait_lock %p",
 			lock->trx->id,
-			stmt ? stmt : "NULL",
 			trx_id,
-			stmt2 ? stmt2 : "NULL",
 			lock->trx->lock.wait_lock);
+
+		if (stmt) {
+			ib_logf(IB_LOG_LEVEL_INFO, " SQL1: %s\n", stmt);
+		}
+
+		if (stmt2) {
+			ib_logf(IB_LOG_LEVEL_INFO, " SQL2: %s\n", stmt2);
+		}
+
 		ut_ad(lock->trx->lock.wait_lock == lock);
 	}
 
@@ -1162,7 +1169,7 @@ lock_rec_has_to_wait(
 						type_mode, lock_is_on_supremum);
 					fprintf(stderr,
 						"conflicts states: my %d locked %d\n",
-						wsrep_thd_conflict_state(trx->mysql_thd, FALSE), 
+						wsrep_thd_conflict_state(trx->mysql_thd, FALSE),
 						wsrep_thd_conflict_state(lock2->trx->mysql_thd, FALSE) );
 					lock_rec_print(stderr, lock2);
 					if (for_locking) return FALSE;
@@ -1714,7 +1721,7 @@ lock_rec_other_has_expl_req(
 	ulint			heap_no,/*!< in: heap number of the record */
 	trx_id_t		trx_id)	/*!< in: transaction */
 {
-	const lock_t*	lock;
+	lock_t*	lock;
 
 	ut_ad(lock_mutex_own());
 	ut_ad(mode == LOCK_X || mode == LOCK_S);
@@ -1723,7 +1730,7 @@ lock_rec_other_has_expl_req(
 
 	for (lock = lock_rec_get_first(block, heap_no);
 	     lock != NULL;
-	     lock = lock_rec_get_next_const(heap_no, lock)) {
+	     lock = lock_rec_get_next(heap_no, lock)) {
 
 		if (lock->trx->id != trx_id
 		    && (gap
@@ -1810,7 +1817,7 @@ Checks if some other transaction has a conflicting explicit lock request
 in the queue, so that we have to wait.
 @return	lock or NULL */
 static
-const lock_t*
+lock_t*
 lock_rec_other_has_conflicting(
 /*===========================*/
 	enum lock_mode		mode,	/*!< in: LOCK_S or LOCK_X,
@@ -1822,7 +1829,7 @@ lock_rec_other_has_conflicting(
 	ulint			heap_no,/*!< in: heap number of the record */
 	const trx_t*		trx)	/*!< in: our transaction */
 {
-	const lock_t*		lock;
+	lock_t*		lock;
 	ibool			is_supremum;
 
 	ut_ad(lock_mutex_own());
@@ -1831,13 +1838,16 @@ lock_rec_other_has_conflicting(
 
 	for (lock = lock_rec_get_first(block, heap_no);
 	     lock != NULL;
-	     lock = lock_rec_get_next_const(heap_no, lock)) {
+	     lock = lock_rec_get_next(heap_no, lock)) {
 
 #ifdef WITH_WSREP
 		if (lock_rec_has_to_wait(TRUE, trx, mode, lock, is_supremum)) {
 			if (wsrep_on_trx(trx)) {
 				trx_mutex_enter(lock->trx);
-				wsrep_kill_victim(trx, lock);
+				/* Below function will roll back either trx
+				or lock->trx depending on priority of the
+				transaction. */
+				wsrep_kill_victim(const_cast<trx_t*>(trx), lock);
 				trx_mutex_exit(lock->trx);
 			}
 #else
@@ -2045,15 +2055,17 @@ wsrep_print_wait_locks(
 {
 	if (wsrep_debug &&  c_lock->trx->lock.wait_lock != c_lock) {
 		fprintf(stderr, "WSREP: c_lock != wait lock\n");
-		if (lock_get_type_low(c_lock) & LOCK_TABLE)
+		if (lock_get_type_low(c_lock) & LOCK_TABLE) {
 			lock_table_print(stderr, c_lock);
-		else
+		} else {
 			lock_rec_print(stderr, c_lock);
+		}
 
-		if (lock_get_type_low(c_lock->trx->lock.wait_lock) & LOCK_TABLE)
+		if (lock_get_type_low(c_lock->trx->lock.wait_lock) & LOCK_TABLE) {
 			lock_table_print(stderr, c_lock->trx->lock.wait_lock);
-		else
+		} else {
 			lock_rec_print(stderr, c_lock->trx->lock.wait_lock);
+		}
 	}
 }
 #endif /* WITH_WSREP */
@@ -2358,8 +2370,8 @@ lock_rec_create(
 			if (wsrep_debug) {
 				fprintf(
 					stderr,
-					"WSREP: c_lock canceled %llu\n",
-					(ulonglong) c_lock->trx->id);
+					"WSREP: c_lock canceled " TRX_ID_FMT "\n",
+					c_lock->trx->id);
 			}
 
 			/* have to bail out here to avoid lock_set_lock... */
@@ -2551,6 +2563,16 @@ lock_rec_enqueue_waiting(
 		err = DB_LOCK_WAIT;
 	}
 
+#ifdef WITH_WSREP
+	if (!lock_get_wait(lock) && wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
+		if (wsrep_debug) {
+			fprintf(stderr, "WSREP: BF thread got lock granted early, ID " TRX_ID_FMT
+				"\n",
+				lock->trx->id);
+		}
+		return(DB_SUCCESS);
+        }
+#endif /* WITH_WSREP */
 	// Move it only when it does not cause a deadlock.
 	if (err != DB_DEADLOCK
 		&& innodb_lock_schedule_algorithm
@@ -2981,6 +3003,15 @@ lock_rec_has_to_wait_in_queue(
 #ifdef WITH_WSREP
 			if (wsrep_thd_is_BF(wait_lock->trx->mysql_thd, FALSE) &&
 			    wsrep_thd_is_BF(lock->trx->mysql_thd, TRUE)) {
+				if (wsrep_debug) {
+					fprintf(stderr,
+						"BF-BF lock conflict " TRX_ID_FMT
+						" : " TRX_ID_FMT "\n",
+						wait_lock->trx->id,
+						lock->trx->id);
+					lock_rec_print(stderr, wait_lock);
+					lock_rec_print(stderr, lock);
+				}
 				/* don't wait for another BF lock */
 				continue;
 			}
@@ -3139,7 +3170,7 @@ lock_grant_and_move_on_page(
 			&& !lock_rec_has_to_wait_in_queue(lock)) {
 			
 			lock_grant(lock, false);
-			
+
 			if (previous != NULL) {
 				/* Move the lock to the head of the list. */
 				HASH_GET_NEXT(hash, previous) = HASH_GET_NEXT(hash, lock);
@@ -5017,8 +5048,8 @@ lock_table_create(
 			}
 
 			if (wsrep_debug) {
-				fprintf(stderr, "WSREP: c_lock canceled %llu\n",
-					(ulonglong) c_lock->trx->id);
+				fprintf(stderr, "WSREP: c_lock canceled " TRX_ID_FMT "\n",
+					c_lock->trx->id);
 			}
 		}
 		if (c_lock) {
@@ -5297,7 +5328,7 @@ Checks if other transactions have an incompatible mode lock request in
 the lock queue.
 @return	lock or NULL */
 UNIV_INLINE
-const lock_t*
+lock_t*
 lock_table_other_has_incompatible(
 /*==============================*/
 	const trx_t*		trx,	/*!< in: transaction, or NULL if all
@@ -5308,7 +5339,7 @@ lock_table_other_has_incompatible(
 	const dict_table_t*	table,	/*!< in: table */
 	enum lock_mode		mode)	/*!< in: lock mode */
 {
-	const lock_t*	lock;
+	lock_t*	lock;
 
 	ut_ad(lock_mutex_own());
 
@@ -5361,7 +5392,7 @@ lock_table(
 #endif
 	trx_t*		trx;
 	dberr_t		err;
-	const lock_t*	wait_for;
+	lock_t*		wait_for;
 
 	ut_ad(table != NULL);
 	ut_ad(thr != NULL);
@@ -5412,13 +5443,13 @@ lock_table(
 
 	if (wait_for != NULL) {
 #ifdef WITH_WSREP
-                err = lock_table_enqueue_waiting((ib_lock_t*)wait_for, mode | flags, table, thr);
+		err = lock_table_enqueue_waiting(wait_for, mode | flags, table, thr);
 #else
 		err = lock_table_enqueue_waiting(mode | flags, table, thr);
 #endif
 	} else {
 #ifdef WITH_WSREP
-	        lock_table_create(c_lock, table, mode | flags, trx);
+		lock_table_create(c_lock, table, mode | flags, trx);
 #else
 		lock_table_create(table, mode | flags, trx);
 #endif
@@ -7101,10 +7132,10 @@ lock_rec_insert_check_and_lock(
 	on the successor, which produced an unnecessary deadlock. */
 
 #ifdef WITH_WSREP
-	if ((c_lock = (ib_lock_t*)lock_rec_other_has_conflicting(
-		    static_cast<enum lock_mode>(
-                            LOCK_X | LOCK_GAP | LOCK_INSERT_INTENTION),
-		    block, next_rec_heap_no, trx))) {
+	if ((c_lock = lock_rec_other_has_conflicting(
+		static_cast<enum lock_mode>(
+			LOCK_X | LOCK_GAP | LOCK_INSERT_INTENTION),
+		block, next_rec_heap_no, trx))) {
 #else
 	if (lock_rec_other_has_conflicting(
 		    static_cast<enum lock_mode>(
@@ -7117,7 +7148,7 @@ lock_rec_insert_check_and_lock(
 
 #ifdef WITH_WSREP
 		err = lock_rec_enqueue_waiting(c_lock,
-                        LOCK_X | LOCK_GAP | LOCK_INSERT_INTENTION,
+			LOCK_X | LOCK_GAP | LOCK_INSERT_INTENTION,
 			block, next_rec_heap_no, index, thr);
 #else
 		err = lock_rec_enqueue_waiting(
diff --git a/storage/xtradb/lock/lock0wait.cc b/storage/xtradb/lock/lock0wait.cc
index ca9d05a4829..a0f557e18e5 100644
--- a/storage/xtradb/lock/lock0wait.cc
+++ b/storage/xtradb/lock/lock0wait.cc
@@ -191,22 +191,25 @@ lock_wait_table_reserve_slot(
 /*********************************************************************//**
 check if lock timeout was for priority thread, 
 as a side effect trigger lock monitor
+@param[in]    trx    transaction owning the lock
+@param[in]    locked true if trx and lock_sys_mutex is ownd
 @return        false for regular lock timeout */
-static ibool
+static
+bool
 wsrep_is_BF_lock_timeout(
-/*====================*/
-    trx_t* trx) /* in: trx to check for lock priority */
+	const trx_t*	trx,
+	bool		locked = true)
 {
-       if (wsrep_on_trx(trx) &&
-           wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
-               fprintf(stderr, "WSREP: BF lock wait long\n");
-                srv_print_innodb_monitor       = TRUE;
-                srv_print_innodb_lock_monitor  = TRUE;
-                os_event_set(srv_monitor_event);
-                return TRUE;
-       }
-       return FALSE;
- }
+	if (wsrep_on_trx(trx)
+	    && wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
+		fprintf(stderr, "WSREP: BF lock wait long for trx " TRX_ID_FMT "\n", trx->id);
+		srv_print_innodb_monitor	= TRUE;
+		srv_print_innodb_lock_monitor	= TRUE;
+		os_event_set(srv_monitor_event);
+		return true;
+	}
+	return false;
+}
 #endif /* WITH_WSREP */
 
 /***************************************************************//**
@@ -402,15 +405,15 @@ lock_wait_suspend_thread(
 	if (lock_wait_timeout < 100000000
 	    && wait_time > (double) lock_wait_timeout) {
 #ifdef WITH_WSREP
-                if (!wsrep_on_trx(trx) ||
-                    (!wsrep_is_BF_lock_timeout(trx) &&
-                     trx->error_state != DB_DEADLOCK)) {
+		if (!wsrep_on_trx(trx) ||
+		    (!wsrep_is_BF_lock_timeout(trx) &&
+		     trx->error_state != DB_DEADLOCK)) {
 #endif /* WITH_WSREP */
 
-		trx->error_state = DB_LOCK_WAIT_TIMEOUT;
+			trx->error_state = DB_LOCK_WAIT_TIMEOUT;
 
 #ifdef WITH_WSREP
-                }
+		}
 #endif /* WITH_WSREP */
 		MONITOR_INC(MONITOR_TIMEOUT);
 	}