MDEV-24813 Signal full scan to storage engines, with innodb implementation

Author: mariadb-YuchenPei

include/my_base.h

@@ -231,6 +231,7 @@ enum ha_extra_function {
   /** Abort of writing rows during ALTER TABLE..ALGORITHM=COPY or
   CREATE..SELCT */
   HA_EXTRA_ABORT_ALTER_COPY
+  , HA_EXTRA_FULL_SCAN_NO_FILTER
 };
 
 /* Compatible option, to be deleted in 6.0 */

mysql-test/main/innodb_full_scan.result

@@ -0,0 +1,18 @@
+#
+# MDEV-24813 Locking full table scan fails to use table-level locking
+#
+CREATE TABLE t (a INT PRIMARY KEY) ENGINE=InnoDB;
+insert into t values (42);
+set global innodb_monitor_enable="lock_rec_lock_created";
+BEGIN;
+SELECT * FROM t LOCK IN SHARE MODE;
+a
+42
+COMMIT;
+SELECT COUNT FROM INFORMATION_SCHEMA.INNODB_METRICS WHERE NAME = 'lock_rec_lock_created';
+COUNT
+0
+set global innodb_monitor_enable=default;
+Warnings:
+Warning	1230	Default value is not defined for this set option. Please specify correct counter or module name.
+DROP TABLE t;

mysql-test/main/innodb_full_scan.test

@@ -0,0 +1,15 @@
+--source include/have_innodb.inc
+--echo #
+--echo # MDEV-24813 Locking full table scan fails to use table-level locking
+--echo #
+
+CREATE TABLE t (a INT PRIMARY KEY) ENGINE=InnoDB;
+insert into t values (42);
+
+set global innodb_monitor_enable="lock_rec_lock_created";
+BEGIN;
+SELECT * FROM t LOCK IN SHARE MODE;
+COMMIT;
+SELECT COUNT FROM INFORMATION_SCHEMA.INNODB_METRICS WHERE NAME = 'lock_rec_lock_created';
+set global innodb_monitor_enable=default;
+DROP TABLE t;

sql/ha_partition.cc

@@ -9495,6 +9495,8 @@ int ha_partition::extra(enum ha_extra_function operation)
   case HA_EXTRA_END_ALTER_COPY:
   case HA_EXTRA_ABORT_ALTER_COPY:
     DBUG_RETURN(loop_partitions(extra_cb, &operation));
+  case HA_EXTRA_FULL_SCAN_NO_FILTER:
+    break;
   default:
   {
     /* Temporary crash to discover what is wrong */

sql/handler.cc

@@ -8692,6 +8692,12 @@ int get_select_field_pos(Alter_info *alter_info, int select_field_count,
   return select_field_pos;
 }
 
+void init_table_full_scan_if_needed(TABLE *table, Item *cond, ha_rows limit)
+{
+  if (!cond && !limit)
+    table->file->extra(HA_EXTRA_FULL_SCAN_NO_FILTER);
+}
+
 
 bool Table_scope_and_contents_source_st::vers_check_system_fields(
         THD *thd, Alter_info *alter_info, const Lex_table_name &table_name,

sql/handler.h

@@ -5811,4 +5811,5 @@ int get_select_field_pos(Alter_info *alter_info, int select_field_count,
 #ifndef DBUG_OFF
 String dbug_format_row(TABLE *table, const uchar *rec, bool print_names= true);
 #endif /* DBUG_OFF */
+void init_table_full_scan_if_needed(TABLE *table, Item *cond, ha_rows limit);
 #endif /* HANDLER_INCLUDED */

sql/records.cc

@@ -336,6 +336,9 @@ bool init_read_record(READ_RECORD *info,THD *thd, TABLE *table,
       (void) table->file->extra_opt(HA_EXTRA_CACHE,
                                     thd->variables.read_buff_size);
   }
+  /* TODO: we are passing 0 as LIMIT */
+  if (select)
+    init_table_full_scan_if_needed(table, select->cond, 0);
   /* Condition pushdown to storage engine */
   if ((table->file->ha_table_flags() & HA_CAN_TABLE_CONDITION_PUSHDOWN) &&
       select && select->cond && 

storage/innobase/handler/ha_innodb.cc

@@ -15892,6 +15892,9 @@ ha_innobase::extra(
 			return(HA_ERR_ROLLBACK);
 		}
 		break;
+	case HA_EXTRA_FULL_SCAN_NO_FILTER:
+		m_prebuilt->full_table_scan= true;
+		break;
 	default:/* Do nothing */
 		;
 	}

storage/innobase/include/row0mysql.h

@@ -695,6 +695,11 @@ struct row_prebuilt_t {
 	/** The MySQL table object */
 	TABLE*		m_mysql_table;
 
+  bool    full_table_scan; /*!< Whether the full table will need to be
+				  scanned. Set when the sql layer passes NULL cond in
+				  cond_push. Will cause to use X/S locks in select rather than
+				  IX/IS locks */
+
 	/** Get template by dict_table_t::cols[] number */
 	const mysql_row_templ_t* get_template_by_col(ulint col) const
 	{

storage/innobase/row/row0sel.cc

@@ -4718,8 +4718,10 @@ row_search_mvcc(
 		} else {
 wait_table_again:
 			err = lock_table(prebuilt->table, nullptr,
-					 prebuilt->select_lock_type == LOCK_S
-					 ? LOCK_IS : LOCK_IX, thr);
+                       prebuilt->full_table_scan ?
+                       prebuilt->select_lock_type :
+                       (prebuilt->select_lock_type == LOCK_S
+                        ? LOCK_IS : LOCK_IX), thr);
 
 			if (err != DB_SUCCESS) {