Merge branch '10.2' into 10.3

13 files changed, 267 insertions, 126 deletions

diff --git a/storage/innobase/btr/btr0cur.cc b/storage/innobase/btr/btr0cur.cc
index 6f91d7ac898..572eb0ee5c7 100644
--- a/storage/innobase/btr/btr0cur.cc
+++ b/storage/innobase/btr/btr0cur.cc
@@ -3,7 +3,7 @@
 Copyright (c) 1994, 2019, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, Google Inc.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2015, 2020, MariaDB Corporation.
+Copyright (c) 2015, 2021, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -67,6 +67,9 @@ Created 10/16/1994 Heikki Tuuri
 #include "srv0start.h"
 #include "mysql_com.h"
 #include "dict0stats.h"
+#ifdef WITH_WSREP
+#include "mysql/service_wsrep.h"
+#endif /* WITH_WSREP */
 
 /** Buffered B-tree operation types, introduced as part of delete buffering. */
 enum btr_op_t {
@@ -3158,7 +3161,8 @@ btr_cur_ins_lock_and_undo(
 
 	/* Check if there is predicate or GAP lock preventing the insertion */
 	if (!(flags & BTR_NO_LOCKING_FLAG)) {
-		if (dict_index_is_spatial(index)) {
+		const unsigned type = index->type;
+		if (UNIV_UNLIKELY(type & DICT_SPATIAL)) {
 			lock_prdt_t	prdt;
 			rtr_mbr_t	mbr;
 
@@ -3175,9 +3179,30 @@ btr_cur_ins_lock_and_undo(
 				index, thr, mtr, &prdt);
 			*inherit = false;
 		} else {
+#ifdef WITH_WSREP
+			trx_t* trx= thr_get_trx(thr);
+			/* If transaction scanning an unique secondary
+			key is wsrep high priority thread (brute
+			force) this scanning may involve GAP-locking
+			in the index. As this locking happens also
+			when applying replication events in high
+			priority applier threads, there is a
+			probability for lock conflicts between two
+			wsrep high priority threads. To avoid this
+			GAP-locking we mark that this transaction
+			is using unique key scan here. */
+			if ((type & (DICT_CLUSTERED | DICT_UNIQUE)) == DICT_UNIQUE
+			    && trx->is_wsrep()
+			    && wsrep_thd_is_BF(trx->mysql_thd, false)) {
+				trx->wsrep_UK_scan= true;
+			}
+#endif /* WITH_WSREP */
 			err = lock_rec_insert_check_and_lock(
 				flags, rec, btr_cur_get_block(cursor),
 				index, thr, mtr, inherit);
+#ifdef WITH_WSREP
+			trx->wsrep_UK_scan= false;
+#endif /* WITH_WSREP */
 		}
 	}
 
diff --git a/storage/innobase/fil/fil0fil.cc b/storage/innobase/fil/fil0fil.cc
index da556ec916c..d3d8e390639 100644
--- a/storage/innobase/fil/fil0fil.cc
+++ b/storage/innobase/fil/fil0fil.cc
@@ -2904,7 +2904,6 @@ fil_rename_tablespace(
 	ut_ad(strchr(new_file_name, OS_PATH_SEPARATOR) != NULL);
 
 	if (!recv_recovery_is_on()) {
-		fil_name_write_rename(id, old_file_name, new_file_name);
 		log_mutex_enter();
 	}
 
diff --git a/storage/innobase/fts/fts0fts.cc b/storage/innobase/fts/fts0fts.cc
index eb2bef4b953..859ec5051f2 100644
--- a/storage/innobase/fts/fts0fts.cc
+++ b/storage/innobase/fts/fts0fts.cc
@@ -1708,7 +1708,7 @@ fts_drop_tables(
 
 	error = fts_drop_common_tables(trx, &fts_table);
 
-	if (error == DB_SUCCESS) {
+	if (error == DB_SUCCESS && table->fts) {
 		error = fts_drop_all_index_tables(trx, table->fts);
 	}
 
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index f172273e11e..01f5ad7173a 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -4,7 +4,7 @@ Copyright (c) 2000, 2020, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, 2009 Google Inc.
 Copyright (c) 2009, Percona Inc.
 Copyright (c) 2012, Facebook Inc.
-Copyright (c) 2013, 2020, MariaDB Corporation.
+Copyright (c) 2013, 2021, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -60,6 +60,7 @@ this program; if not, write to the Free Software Foundation, Inc.,
 
 #include <my_service_manager.h>
 #include <key.h>
+#include <sql_manager.h>
 
 /* Include necessary InnoDB headers */
 #include "btr0btr.h"
@@ -156,11 +157,8 @@ wsrep_ws_handle(THD* thd, const trx_t* trx) {
 }
 
 extern void wsrep_cleanup_transaction(THD *thd);
-static int
-wsrep_abort_transaction(handlerton* hton, THD *bf_thd, THD *victim_thd,
-			my_bool signal);
-static void
-wsrep_fake_trx_id(handlerton* hton, THD *thd);
+static void wsrep_abort_transaction(handlerton*, THD *, THD *, my_bool);
+static void wsrep_fake_trx_id(handlerton* hton, THD *thd);
 static int innobase_wsrep_set_checkpoint(handlerton* hton, const XID* xid);
 static int innobase_wsrep_get_checkpoint(handlerton* hton, XID* xid);
 #endif /* WITH_WSREP */
@@ -3507,6 +3505,12 @@ static int innodb_init_abort()
 	DBUG_RETURN(1);
 }
 
+/** Deprecation message about innodb_idle_flush_pct */
+static const char*	deprecated_idle_flush_pct
+	= "innodb_idle_flush_pct is DEPRECATED and has no effect.";
+
+static ulong innodb_idle_flush_pct;
+
 /** If applicable, emit a message that log checksums cannot be disabled.
 @param[in,out]	thd	client session, or NULL if at startup
 @param[in]	check	whether redo log block checksums are enabled
@@ -5023,6 +5027,7 @@ innobase_close_connection(
 
 	if (trx) {
 
+		thd_set_ha_data(thd, hton, NULL);
 		if (!trx_is_registered_for_2pc(trx) && trx_is_started(trx)) {
 
 			sql_print_error("Transaction not registered for MariaDB 2PC, "
@@ -17288,7 +17293,8 @@ innodb_io_capacity_update(
 				    " higher than innodb_io_capacity_max %lu",
 				    in_val, srv_max_io_capacity);
 
-		srv_max_io_capacity = in_val * 2;
+		srv_max_io_capacity = (in_val & ~(~0UL >> 1))
+			? in_val : in_val * 2;
 
 		push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
 				    ER_WRONG_ARGUMENTS,
@@ -18743,69 +18749,57 @@ wsrep_abort_slave_trx(
 		(long long)bf_seqno, (long long)victim_seqno);
 	abort();
 }
-/*******************************************************************//**
-This function is used to kill one transaction in BF. */
-UNIV_INTERN
-int
-wsrep_innobase_kill_one_trx(
-/*========================*/
-	void * const bf_thd_ptr,
-	const trx_t * const bf_trx,
-	trx_t *victim_trx,
-	ibool signal)
-{
-        ut_ad(lock_mutex_own());
-        ut_ad(trx_mutex_own(victim_trx));
-        ut_ad(bf_thd_ptr);
-        ut_ad(victim_trx);
 
-	DBUG_ENTER("wsrep_innobase_kill_one_trx");
-	THD *bf_thd       = bf_thd_ptr ? (THD*) bf_thd_ptr : NULL;
-	THD *thd          = (THD *) victim_trx->mysql_thd;
-	int64_t bf_seqno  = (bf_thd) ? wsrep_thd_trx_seqno(bf_thd) : 0;
+struct bg_wsrep_kill_trx_arg {
+	my_thread_id	thd_id;
+	trx_id_t	trx_id;
+	int64_t		bf_seqno;
+	ibool		signal;
+};
 
-	if (!thd) {
-		DBUG_PRINT("wsrep", ("no thd for conflicting lock"));
-		WSREP_WARN("no THD for trx: " TRX_ID_FMT, victim_trx->id);
-		DBUG_RETURN(1);
-	}
+static void bg_wsrep_kill_trx(
+	void *void_arg)
+{
+	bg_wsrep_kill_trx_arg *arg = (bg_wsrep_kill_trx_arg*)void_arg;
+	THD *thd 		   = find_thread_by_id(arg->thd_id, false);
+	trx_t *victim_trx 	   = NULL;
+	bool awake 		   = false;
+	DBUG_ENTER("bg_wsrep_kill_trx");
 
-	if (!bf_thd) {
-		DBUG_PRINT("wsrep", ("no BF thd for conflicting lock"));
-		WSREP_WARN("no BF THD for trx: " TRX_ID_FMT,
-			   bf_trx ? bf_trx->id : 0);
-		DBUG_RETURN(1);
+	if (thd) {
+		victim_trx = thd_to_trx(thd);
+		lock_mutex_enter();
+		trx_mutex_enter(victim_trx);
+		if (victim_trx->id != arg->trx_id)
+		{
+			trx_mutex_exit(victim_trx);
+			lock_mutex_exit();
+			wsrep_thd_UNLOCK(thd);
+			victim_trx = NULL;
+		}
 	}
 
-	WSREP_LOG_CONFLICT(bf_thd, thd, TRUE);
+	if (!victim_trx) {
+		/* it can happen that trx_id was meanwhile rolled back */
+		DBUG_PRINT("wsrep", ("no thd for conflicting lock"));
+		goto ret;
+	}
 
 	WSREP_DEBUG("BF kill (" ULINTPF ", seqno: " INT64PF
 		    "), victim: (%lu) trx: " TRX_ID_FMT,
-		    signal, bf_seqno,
+		    arg->signal, arg->bf_seqno,
 		    thd_get_thread_id(thd),
 		    victim_trx->id);
 
 	WSREP_DEBUG("Aborting query: %s conf %d trx: %" PRId64,
-		    (thd && wsrep_thd_query(thd)) ? wsrep_thd_query(thd) : "void",
+		    (wsrep_thd_query(thd)) ? wsrep_thd_query(thd) : "void",
 		    wsrep_thd_conflict_state(thd, FALSE),
 		    wsrep_thd_ws_handle(thd)->trx_id);
 
-	wsrep_thd_LOCK(thd);
-        DBUG_EXECUTE_IF("sync.wsrep_after_BF_victim_lock",
-                 {
-                   const char act[]=
-                     "now "
-                     "wait_for signal.wsrep_after_BF_victim_lock";
-                   DBUG_ASSERT(!debug_sync_set_action(bf_thd,
-                                                      STRING_WITH_LEN(act)));
-                 };);
-
-
 	if (wsrep_thd_query_state(thd) == QUERY_EXITING) {
 		WSREP_DEBUG("kill trx EXITING for " TRX_ID_FMT,
 			    victim_trx->id);
-		wsrep_thd_UNLOCK(thd);
-		DBUG_RETURN(0);
+		goto ret_unlock;
 	}
 
 	if (wsrep_thd_exec_mode(thd) != LOCAL_STATE) {
@@ -18821,18 +18815,13 @@ wsrep_innobase_kill_one_trx(
         case MUST_ABORT:
 		WSREP_DEBUG("victim " TRX_ID_FMT " in MUST ABORT state",
 			    victim_trx->id);
-		wsrep_thd_UNLOCK(thd);
-		wsrep_thd_awake(thd, signal);
-		DBUG_RETURN(0);
-		break;
+		goto ret_awake;
 	case ABORTED:
 	case ABORTING: // fall through
 	default:
 		WSREP_DEBUG("victim " TRX_ID_FMT " in state %d",
 			    victim_trx->id, wsrep_thd_get_conflict_state(thd));
-		wsrep_thd_UNLOCK(thd);
-		DBUG_RETURN(0);
-		break;
+		goto ret_unlock;
 	}
 
 	switch (wsrep_thd_query_state(thd)) {
@@ -18845,12 +18834,12 @@ wsrep_innobase_kill_one_trx(
 			    victim_trx->id);
 
 		if (wsrep_thd_exec_mode(thd) == REPL_RECV) {
-			wsrep_abort_slave_trx(bf_seqno,
+			wsrep_abort_slave_trx(arg->bf_seqno,
 					      wsrep_thd_trx_seqno(thd));
 		} else {
 			wsrep_t *wsrep= get_wsrep();
 			rcode = wsrep->abort_pre_commit(
-				wsrep, bf_seqno,
+				wsrep, arg->bf_seqno,
 				(wsrep_trx_id_t)wsrep_thd_ws_handle(thd)->trx_id
 			);
 
@@ -18859,10 +18848,7 @@ wsrep_innobase_kill_one_trx(
 				WSREP_DEBUG("cancel commit warning: "
 					    TRX_ID_FMT,
 					    victim_trx->id);
-				wsrep_thd_UNLOCK(thd);
-				wsrep_thd_awake(thd, signal);
-				DBUG_RETURN(1);
-				break;
+				goto ret_awake;
 			case WSREP_OK:
 				break;
 			default:
@@ -18875,12 +18861,9 @@ wsrep_innobase_kill_one_trx(
 				 * kill the lock holder first.
 				 */
 				abort();
-				break;
 			}
 		}
-		wsrep_thd_UNLOCK(thd);
-		wsrep_thd_awake(thd, signal);
-		break;
+		goto ret_awake;
 	case QUERY_EXEC:
 		/* it is possible that victim trx is itself waiting for some
 		 * other lock. We need to cancel this waiting
@@ -18901,26 +18884,20 @@ wsrep_innobase_kill_one_trx(
 				lock_cancel_waiting_and_release(wait_lock);
 			}
 
-			wsrep_thd_UNLOCK(thd);
-			wsrep_thd_awake(thd, signal);
 		} else {
 			/* abort currently executing query */
 			DBUG_PRINT("wsrep",("sending KILL_QUERY to: %lu",
                                             thd_get_thread_id(thd)));
 			WSREP_DEBUG("kill query for: %ld",
 				thd_get_thread_id(thd));
-			/* Note that innobase_kill_query will take lock_mutex
-			and trx_mutex */
-			wsrep_thd_UNLOCK(thd);
-			wsrep_thd_awake(thd, signal);
 
 			/* for BF thd, we need to prevent him from committing */
 			if (wsrep_thd_exec_mode(thd) == REPL_RECV) {
-				wsrep_abort_slave_trx(bf_seqno,
+				wsrep_abort_slave_trx(arg->bf_seqno,
 						    wsrep_thd_trx_seqno(thd));
 			}
 		}
-		break;
+		goto ret_awake;
 	case QUERY_IDLE:
 	{
 		WSREP_DEBUG("kill IDLE for " TRX_ID_FMT, victim_trx->id);
@@ -18928,10 +18905,9 @@ wsrep_innobase_kill_one_trx(
 		if (wsrep_thd_exec_mode(thd) == REPL_RECV) {
 			WSREP_DEBUG("kill BF IDLE, seqno: %lld",
 				    (long long)wsrep_thd_trx_seqno(thd));
-			wsrep_thd_UNLOCK(thd);
-			wsrep_abort_slave_trx(bf_seqno,
+			wsrep_abort_slave_trx(arg->bf_seqno,
 					      wsrep_thd_trx_seqno(thd));
-			DBUG_RETURN(0);
+			goto ret_unlock;
 		}
                 /* This will lock thd from proceeding after net_read() */
 		wsrep_thd_set_conflict_state(thd, ABORTING);
@@ -18952,22 +18928,72 @@ wsrep_innobase_kill_one_trx(
 		DBUG_PRINT("wsrep",("signalling wsrep rollbacker"));
 		WSREP_DEBUG("signaling aborter");
 		wsrep_unlock_rollback();
-		wsrep_thd_UNLOCK(thd);
-
-		break;
+		goto ret_unlock;
 	}
 	default:
 		WSREP_WARN("bad wsrep query state: %d",
 			  wsrep_thd_query_state(thd));
-		wsrep_thd_UNLOCK(thd);
-		break;
+		goto ret_unlock;
 	}
 
-	DBUG_RETURN(0);
+ret_awake:
+	awake = true;
+
+ret_unlock:
+	trx_mutex_exit(victim_trx);
+	lock_mutex_exit();
+	if (awake)
+		wsrep_thd_awake(thd, arg->signal);
+	wsrep_thd_UNLOCK(thd);
+
+ret:
+	free(arg);
+	DBUG_VOID_RETURN;
+
+}
+
+/*******************************************************************//**
+This function is used to kill one transaction in BF. */
+UNIV_INTERN
+void
+wsrep_innobase_kill_one_trx(
+/*========================*/
+	MYSQL_THD const bf_thd,
+	const trx_t * const bf_trx,
+	trx_t *victim_trx,
+	ibool signal)
+{
+	ut_ad(bf_thd);
+	ut_ad(victim_trx);
+	ut_ad(lock_mutex_own());
+	ut_ad(trx_mutex_own(victim_trx));
+
+	bg_wsrep_kill_trx_arg *arg = (bg_wsrep_kill_trx_arg*)malloc(sizeof(*arg));
+	arg->thd_id	= thd_get_thread_id(victim_trx->mysql_thd);
+	arg->trx_id	= victim_trx->id;
+	arg->bf_seqno	= wsrep_thd_trx_seqno((THD*)bf_thd);
+	arg->signal	= signal;
+
+	DBUG_ENTER("wsrep_innobase_kill_one_trx");
+
+	WSREP_LOG_CONFLICT(bf_thd, victim_trx->mysql_thd, TRUE);
+
+	DBUG_EXECUTE_IF("sync.wsrep_after_BF_victim_lock",
+		{
+		  const char act[]=
+		    "now "
+		    "wait_for signal.wsrep_after_BF_victim_lock";
+		  DBUG_ASSERT(!debug_sync_set_action(bf_thd,
+						     STRING_WITH_LEN(act)));
+		};);
+
+
+	mysql_manager_submit(bg_wsrep_kill_trx, arg);
+	DBUG_VOID_RETURN;
 }
 
 static
-int
+void
 wsrep_abort_transaction(
 /*====================*/
 	handlerton*,
@@ -18975,7 +19001,7 @@ wsrep_abort_transaction(
 	THD *victim_thd,
 	my_bool signal)
 {
-	DBUG_ENTER("wsrep_innobase_abort_thd");
+	DBUG_ENTER("wsrep_abort_transaction");
 
 	trx_t* victim_trx	= thd_to_trx(victim_thd);
 	trx_t* bf_trx		= (bf_thd) ? thd_to_trx(bf_thd) : NULL;
@@ -18988,12 +19014,11 @@ wsrep_abort_transaction(
 	if (victim_trx) {
 		lock_mutex_enter();
 		trx_mutex_enter(victim_trx);
-		int rcode = wsrep_innobase_kill_one_trx(bf_thd, bf_trx,
-                                                        victim_trx, signal);
+		wsrep_innobase_kill_one_trx(bf_thd, bf_trx, victim_trx, signal);
 		lock_mutex_exit();
 		trx_mutex_exit(victim_trx);
 		wsrep_srv_conc_cancel_wait(victim_trx);
-		DBUG_RETURN(rcode);
+		DBUG_VOID_RETURN;
 	} else {
 		WSREP_DEBUG("victim does not have transaction");
 		wsrep_thd_LOCK(victim_thd);
@@ -19002,7 +19027,7 @@ wsrep_abort_transaction(
 		wsrep_thd_awake(victim_thd, signal);
 	}
 
-	DBUG_RETURN(-1);
+	DBUG_VOID_RETURN;
 }
 
 static
@@ -19046,6 +19071,14 @@ static void wsrep_fake_trx_id(handlerton *, THD *thd)
 
 #endif /* WITH_WSREP */
 
+static void innodb_idle_flush_pct_update(THD *thd, st_mysql_sys_var *var,
+                                         void*, const void *save)
+{
+  innodb_idle_flush_pct = *static_cast<const ulong*>(save);
+  push_warning(thd, Sql_condition::WARN_LEVEL_WARN,
+               HA_ERR_WRONG_COMMAND, deprecated_idle_flush_pct);
+}
+
 /* plugin options */
 
 static MYSQL_SYSVAR_ENUM(checksum_algorithm, srv_checksum_algorithm,
@@ -19130,12 +19163,10 @@ static MYSQL_SYSVAR_ULONG(io_capacity_max, srv_max_io_capacity,
   SRV_MAX_IO_CAPACITY_DUMMY_DEFAULT, 100,
   SRV_MAX_IO_CAPACITY_LIMIT, 0);
 
-static MYSQL_SYSVAR_ULONG(idle_flush_pct,
-  srv_idle_flush_pct,
+static MYSQL_SYSVAR_ULONG(idle_flush_pct, innodb_idle_flush_pct,
   PLUGIN_VAR_RQCMDARG,
-  "Up to what percentage of dirty pages should be flushed when innodb "
-  "finds it has spare resources to do so.",
-  NULL, NULL, 100, 0, 100, 0);
+  "DEPRECATED. This setting has no effect.",
+  NULL, innodb_idle_flush_pct_update, 100, 0, 100, 0);
 
 #ifdef UNIV_DEBUG
 static MYSQL_SYSVAR_BOOL(background_drop_list_empty,
@@ -20682,7 +20713,7 @@ static bool table_name_parse(
 	memcpy(tbl_buf, tbl_name.m_name + dbnamelen + 1, tblnamelen);
 	tbl_buf[tblnamelen] = 0;
 
-	filename_to_tablename(db_buf, dbname, MAX_DATABASE_NAME_LEN + 1, true);
+	dbnamelen = filename_to_tablename(db_buf, dbname, MAX_DATABASE_NAME_LEN + 1, true);
 
 	if (tblnamelen > TEMP_FILE_PREFIX_LENGTH
 	    && !strncmp(tbl_buf, TEMP_FILE_PREFIX, TEMP_FILE_PREFIX_LENGTH)) {
@@ -20694,7 +20725,7 @@ static bool table_name_parse(
 		tblnamelen = is_part - tbl_buf;
 	}
 
-	filename_to_tablename(tbl_buf, tblname, MAX_TABLE_NAME_LEN + 1, true);
+	tblnamelen = filename_to_tablename(tbl_buf, tblname, MAX_TABLE_NAME_LEN + 1, true);
 	return true;
 }
 
diff --git a/storage/innobase/include/ha_prototypes.h b/storage/innobase/include/ha_prototypes.h
index 51a34b91418..f116cad32e2 100644
--- a/storage/innobase/include/ha_prototypes.h
+++ b/storage/innobase/include/ha_prototypes.h
@@ -231,8 +231,8 @@ innobase_casedn_str(
 
 #ifdef WITH_WSREP
 UNIV_INTERN
-int
-wsrep_innobase_kill_one_trx(void * const thd_ptr,
+void
+wsrep_innobase_kill_one_trx(MYSQL_THD const thd_ptr,
                             const trx_t * const bf_trx,
                             trx_t *victim_trx,
                             ibool signal);
diff --git a/storage/innobase/include/srv0srv.h b/storage/innobase/include/srv0srv.h
index 6c575733710..c587ed6f53d 100644
--- a/storage/innobase/include/srv0srv.h
+++ b/storage/innobase/include/srv0srv.h
@@ -3,7 +3,7 @@
 Copyright (c) 1995, 2017, Oracle and/or its affiliates. All rights reserved.
 Copyright (c) 2008, 2009, Google Inc.
 Copyright (c) 2009, Percona Inc.
-Copyright (c) 2013, 2019, MariaDB Corporation.
+Copyright (c) 2013, 2021, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -413,8 +413,6 @@ extern double	srv_defragment_fill_factor;
 extern uint	srv_defragment_frequency;
 extern ulonglong	srv_defragment_interval;
 
-extern ulong	srv_idle_flush_pct;
-
 extern uint	srv_change_buffer_max_size;
 
 /* Number of IO operations per second the server can do */
diff --git a/storage/innobase/include/trx0trx.h b/storage/innobase/include/trx0trx.h
index ef7623e1db5..c1572a0d07f 100644
--- a/storage/innobase/include/trx0trx.h
+++ b/storage/innobase/include/trx0trx.h
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2020, MariaDB Corporation.
+Copyright (c) 2015, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -819,6 +819,9 @@ public:
 	/** whether wsrep_on(mysql_thd) held at the start of transaction */
 	bool		wsrep;
 	bool is_wsrep() const { return UNIV_UNLIKELY(wsrep); }
+	/** true, if BF thread is performing unique secondary index scanning */
+	bool wsrep_UK_scan;
+	bool is_wsrep_UK_scan() const { return UNIV_UNLIKELY(wsrep_UK_scan); }
 #else /* WITH_WSREP */
 	bool is_wsrep() const { return false; }
 #endif /* WITH_WSREP */
diff --git a/storage/innobase/include/univ.i b/storage/innobase/include/univ.i
index 001690a47a1..9f57380694b 100644
--- a/storage/innobase/include/univ.i
+++ b/storage/innobase/include/univ.i
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2013, 2020, MariaDB Corporation.
+Copyright (c) 2013, 2021, MariaDB Corporation.
 Copyright (c) 2008, Google Inc.
 
 Portions of this file contain modifications contributed and copyrighted by
diff --git a/storage/innobase/lock/lock0lock.cc b/storage/innobase/lock/lock0lock.cc
index a633d440519..da3dba73bee 100644
--- a/storage/innobase/lock/lock0lock.cc
+++ b/storage/innobase/lock/lock0lock.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2014, 2020, MariaDB Corporation.
+Copyright (c) 2014, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -651,6 +651,11 @@ static void wsrep_assert_no_bf_bf_wait(
 {
 	ut_ad(!lock_rec1 || lock_get_type_low(lock_rec1) == LOCK_REC);
 	ut_ad(lock_get_type_low(lock_rec2) == LOCK_REC);
+	ut_ad(lock_mutex_own());
+
+	/* Note that we are holding lock_sys->mutex, thus we should
+	not acquire THD::LOCK_thd_data mutex below to avoid mutexing
+	order violation. */
 
 	if (!trx1->is_wsrep() || !lock_rec2->trx->is_wsrep())
 		return;
@@ -666,12 +671,8 @@ static void wsrep_assert_no_bf_bf_wait(
 	/* avoiding BF-BF conflict assert, if victim is already aborting
 	   or rolling back for replaying
 	*/
-	wsrep_thd_LOCK(lock_rec2->trx->mysql_thd);
-	if (wsrep_trx_is_aborting(lock_rec2->trx->mysql_thd)) {
-		wsrep_thd_UNLOCK(lock_rec2->trx->mysql_thd);
+	if (wsrep_trx_is_aborting(lock_rec2->trx->mysql_thd))
 		return;
-	}
-	wsrep_thd_UNLOCK(lock_rec2->trx->mysql_thd);
 
 	mtr_t mtr;
 
@@ -728,6 +729,7 @@ lock_rec_has_to_wait(
 {
 	ut_ad(trx && lock2);
 	ut_ad(lock_get_type_low(lock2) == LOCK_REC);
+	ut_ad(lock_mutex_own());
 
 	if (trx == lock2->trx
 	    || lock_mode_compatible(
@@ -808,9 +810,23 @@ lock_rec_has_to_wait(
 	}
 
 #ifdef WITH_WSREP
-	/* There should not be two conflicting locks that are
-	brute force. If there is it is a bug. */
-	wsrep_assert_no_bf_bf_wait(NULL, lock2, trx);
+		/* New lock request from a transaction is using unique key
+		scan and this transaction is a wsrep high priority transaction
+		(brute force). If conflicting transaction is also wsrep high
+		priority transaction we should avoid lock conflict because
+		ordering of these transactions is already decided and
+		conflicting transaction will be later replayed. Note
+		that thread holding conflicting lock can't be
+		committed or rolled back while we hold
+		lock_sys->mutex. */
+		if (trx->is_wsrep_UK_scan()
+		    && wsrep_thd_is_BF(lock2->trx->mysql_thd, false)) {
+			return false;
+		}
+
+		/* There should not be two conflicting locks that are
+		brute force. If there is it is a bug. */
+		wsrep_assert_no_bf_bf_wait(NULL, lock2, trx);
 #endif /* WITH_WSREP */
 
 	return true;
@@ -5650,6 +5666,19 @@ lock_sec_rec_modify_check_and_lock(
 
 	heap_no = page_rec_get_heap_no(rec);
 
+#ifdef WITH_WSREP
+	trx_t *trx= thr_get_trx(thr);
+	/* If transaction scanning an unique secondary key is wsrep
+	high priority thread (brute force) this scanning may involve
+	GAP-locking in the index. As this locking happens also when
+	applying replication events in high priority applier threads,
+	there is a probability for lock conflicts between two wsrep
+	high priority threads. To avoid this GAP-locking we mark that
+	this transaction is using unique key scan here. */
+	if (trx->is_wsrep() && wsrep_thd_is_BF(trx->mysql_thd, false))
+		trx->wsrep_UK_scan= true;
+#endif /* WITH_WSREP */
+
 	/* Another transaction cannot have an implicit lock on the record,
 	because when we come here, we already have modified the clustered
 	index record, and this would not have been possible if another active
@@ -5658,6 +5687,10 @@ lock_sec_rec_modify_check_and_lock(
 	err = lock_rec_lock(TRUE, LOCK_X | LOCK_REC_NOT_GAP,
 			    block, heap_no, index, thr);
 
+#ifdef WITH_WSREP
+	trx->wsrep_UK_scan= false;
+#endif /* WITH_WSREP */
+
 #ifdef UNIV_DEBUG
 	{
 		mem_heap_t*	heap		= NULL;
@@ -5749,9 +5782,26 @@ lock_sec_rec_read_check_and_lock(
 		return DB_SUCCESS;
 	}
 
+#ifdef WITH_WSREP
+	trx_t *trx= thr_get_trx(thr);
+	/* If transaction scanning an unique secondary key is wsrep
+	high priority thread (brute force) this scanning may involve
+	GAP-locking in the index. As this locking happens also when
+	applying replication events in high priority applier threads,
+	there is a probability for lock conflicts between two wsrep
+	high priority threads. To avoid this GAP-locking we mark that
+	this transaction is using unique key scan here. */
+	if (trx->is_wsrep() && wsrep_thd_is_BF(trx->mysql_thd, false))
+		trx->wsrep_UK_scan= true;
+#endif /* WITH_WSREP */
+
 	err = lock_rec_lock(FALSE, ulint(mode) | gap_mode,
 			    block, heap_no, index, thr);
 
+#ifdef WITH_WSREP
+	trx->wsrep_UK_scan= false;
+#endif /* WITH_WSREP */
+
 	ut_ad(lock_rec_queue_validate(FALSE, block, rec, index, offsets));
 
 	return(err);
diff --git a/storage/innobase/log/log0recv.cc b/storage/innobase/log/log0recv.cc
index c1200f80b0d..0d6d3015349 100644
--- a/storage/innobase/log/log0recv.cc
+++ b/storage/innobase/log/log0recv.cc
@@ -3930,6 +3930,7 @@ recv_recovery_from_checkpoint_start(lsn_t flush_lsn)
 	mutex_enter(&recv_sys->mutex);
 
 	recv_sys->apply_log_recs = TRUE;
+	recv_no_ibuf_operations = is_mariabackup_restore_or_export();
 
 	mutex_exit(&recv_sys->mutex);
 
diff --git a/storage/innobase/row/row0upd.cc b/storage/innobase/row/row0upd.cc
index 5ca101fdabd..284009becf5 100644
--- a/storage/innobase/row/row0upd.cc
+++ b/storage/innobase/row/row0upd.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2020, MariaDB Corporation.
+Copyright (c) 2015, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -2323,7 +2323,9 @@ row_upd_sec_index_entry(
 		break;
 	}
 
-	if (!index->is_committed()) {
+	bool uncommitted = !index->is_committed();
+
+	if (uncommitted) {
 		/* The index->online_status may change if the index is
 		or was being created online, but not committed yet. It
 		is protected by index->lock. */
@@ -2520,11 +2522,38 @@ row_upd_sec_index_entry(
 
 	mem_heap_empty(heap);
 
+	DEBUG_SYNC_C_IF_THD(trx->mysql_thd,
+			    "before_row_upd_sec_new_index_entry");
+
+	uncommitted = !index->is_committed();
+	if (uncommitted) {
+		mtr.start();
+		/* The index->online_status may change if the index is
+		being rollbacked. It is protected by index->lock. */
+
+		mtr_s_lock_index(index, &mtr);
+
+		switch (dict_index_get_online_status(index)) {
+		case ONLINE_INDEX_COMPLETE:
+		case ONLINE_INDEX_CREATION:
+		       break;
+		case ONLINE_INDEX_ABORTED:
+		case ONLINE_INDEX_ABORTED_DROPPED:
+		       mtr_commit(&mtr);
+		       goto func_exit;
+		}
+
+	}
+
 	/* Build a new index entry */
 	entry = row_build_index_entry(node->upd_row, node->upd_ext,
 				      index, heap);
 	ut_a(entry);
 
+	if (uncommitted) {
+		mtr_commit(&mtr);
+	}
+
 	/* Insert new index entry */
 	err = row_ins_sec_index_entry(index, entry, thr, !node->is_delete);
 
diff --git a/storage/innobase/srv/srv0srv.cc b/storage/innobase/srv/srv0srv.cc
index c5b08cd5eb8..9fd0e097b86 100644
--- a/storage/innobase/srv/srv0srv.cc
+++ b/storage/innobase/srv/srv0srv.cc
@@ -3,7 +3,7 @@
 Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, 2009 Google Inc.
 Copyright (c) 2009, Percona Inc.
-Copyright (c) 2013, 2020, MariaDB Corporation.
+Copyright (c) 2013, 2021, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -256,9 +256,6 @@ ulong srv_buf_pool_load_pages_abort = LONG_MAX;
 /** Lock table size in bytes */
 ulint	srv_lock_table_size	= ULINT_MAX;
 
-/** innodb_idle_flush_pct */
-ulong	srv_idle_flush_pct;
-
 /** innodb_read_io_threads */
 ulong	srv_n_read_io_threads;
 /** innodb_write_io_threads */
diff --git a/storage/innobase/trx/trx0trx.cc b/storage/innobase/trx/trx0trx.cc
index 1511f3b5b77..609ab63ff4c 100644
--- a/storage/innobase/trx/trx0trx.cc
+++ b/storage/innobase/trx/trx0trx.cc
@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2015, 2020, MariaDB Corporation.
+Copyright (c) 2015, 2021, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -161,6 +161,11 @@ trx_init(
 	trx->lock.rec_cached = 0;
 
 	trx->lock.table_cached = 0;
+#ifdef WITH_WSREP
+	ut_ad(!trx->wsrep);
+	ut_ad(!trx->wsrep_event);
+	ut_ad(!trx->wsrep_UK_scan);
+#endif /* WITH_WSREP */
 
 	ut_ad(trx->get_flush_observer() == NULL);
 }
@@ -365,6 +370,7 @@ trx_t *trx_create()
 
 #ifdef WITH_WSREP
 	trx->wsrep_event = NULL;
+	ut_ad(!trx->wsrep_UK_scan);
 #endif /* WITH_WSREP */
 
 	trx_sys.register_trx(trx);
@@ -471,6 +477,8 @@ void trx_t::free()
   MEM_NOACCESS(&flush_observer, sizeof flush_observer);
 #ifdef WITH_WSREP
   MEM_NOACCESS(&wsrep_event, sizeof wsrep_event);
+  ut_ad(!wsrep_UK_scan);
+  MEM_NOACCESS(&wsrep_UK_scan, sizeof wsrep_UK_scan);
 #endif /* WITH_WSREP */
   MEM_NOACCESS(&magic_n, sizeof magic_n);
   trx_pools->mem_free(this);