MDEV-12837: WSREP: BF lock wait long

Problem was a merge error from MySQL wsrep i.e. Galera.

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 fall back to First-Come-First-Served (FCFS)
	with notice to user.

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

lock_reset_lock_and_trx_wait
	Use ib::hex() to print out transaction ID.

lock_rec_other_has_expl_req,
lock_rec_other_has_conflicting,
RecLock::add_to_waitq
lock_rec_lock_slow
lock_table_other_has_incompatible
lock_rec_insert_check_and_lock
lock_prdt_other_has_conflicting

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

RecLock::create
	Conclicting lock pointer is moved to last parameter with
	default value NULL. This conflicting transaction could
	be selected as victim in Galera if requesting transaction
	is BF (brute force) transaction. In this case contents
	of conflicting lock pointer will be changed. Use ib::hex() to print
	transaction ids.

sql/sys_vars.cc

@@ -5005,7 +5005,8 @@ 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 (

sql/wsrep_var.cc

@@ -42,12 +42,28 @@ 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;
 }
 

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;

storage/innobase/handler/ha_innodb.cc

@@ -3862,6 +3862,16 @@ 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) {
+		ib::info() << "In Galera environment Variance-Aware-Transaction-Sheduling Algorithm"
+			   " is not supported. Falling back to First-Come-First-Served order. ";
+		innodb_lock_schedule_algorithm = INNODB_LOCK_SCHEDULE_ALGORITHM_FCFS;
+	}
+#endif /* WITH_WSREP */
+
 #ifndef HAVE_LZ4
 	if (innodb_compression_algorithm == PAGE_LZ4_ALGORITHM) {
 		sql_print_error("InnoDB: innodb_compression_algorithm = %lu unsupported.\n"
@@ -5351,7 +5361,7 @@ innobase_kill_query(
 				wsrep_thd_is_BF(current_thd, FALSE));
 		}
 
-		if (!wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
+		if (!wsrep_thd_is_BF(trx->mysql_thd, FALSE) && trx->abort_type != TRX_WSREP_ABORT) {
 			lock_mutex_enter();
 			lock_mutex_taken = true;
 		}
@@ -20863,7 +20873,7 @@ 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"

storage/innobase/include/lock0priv.h

@@ -721,7 +721,7 @@ class RecLock {
 		as a victim, and we got the lock immediately: no need to
 		wait then */
 	dberr_t add_to_waitq(
-		const lock_t*	wait_for,
+		lock_t*	wait_for,
 		const lock_prdt_t*
 				prdt = NULL);
 
@@ -731,21 +731,22 @@ class RecLock {
 	@param[in] owns_trx_mutex	true if caller owns the trx_t::mutex
 	@param[in] add_to_hash		add the lock to hash table
 	@param[in] prdt			Predicate lock (optional)
+	@param[in,out] c_lock		Conflicting lock request or NULL
+					in Galera conflicting lock is selected
+					as deadlock victim if requester
+					is BF transaction.
 	@return new lock instance */
 	lock_t* create(
 		trx_t*		trx,
 		bool		owns_trx_mutex,
 		bool		add_to_hash,
 		const lock_prdt_t*
-				prdt = NULL);
+				prdt = NULL
+#ifdef WITH_WSREP
+		,lock_t*	c_lock = NULL
+#endif /* WITH_WSREP */
+	);
 
-	lock_t* create(
-		lock_t* const	c_lock,
-		trx_t*		trx,
-		bool		owns_trx_mutex,
-		bool		add_to_hash,
-		const lock_prdt_t*
-				prdt = NULL);
 	/**
 	Check of the lock is on m_rec_id.
 	@param[in] lock			Lock to compare with