MDEV-33538 make auxiliary spider plugins init depend on actual spider

The two I_S plugins SPIDER_ALLOC_MEM and SPIDER_WRAPPER_PROTOCOL only makes sense if the main SPIDER plugin is installed. Further, SPIDER_ALLOC_MEM requires a mutex that requires SPIDER init to fill the table. We also update the spider init query to override --transaction_read_only=on so that it does not affect the spider init. Also fixed error handling in spider_db_init() so that failure in spider table init does not result in memory leak

Author: mariadb-YuchenPei

sql/handler.cc

@@ -641,13 +641,6 @@ int ha_initialize_handlerton(st_plugin_int *plugin)
  hton->slot= HA_SLOT_UNDEF;
  /* Historical Requirement */
  plugin->data= hton; // shortcut for the future
- /* [remove after merge] notes on merge conflict (MDEV-31400):
- 10.6-10.11: 13ba00ff4933cfc1712676f323587504e453d1b5
- 11.0-11.2: 42f8be10f18163c4025710cf6a212e82bddb2f62
- The 10.11->11.0 conflict is trivial, but the reference commit also
- contains different non-conflict changes needs to be applied to 11.0
- (and beyond).
- */
  if (plugin->plugin->init && (ret= plugin->plugin->init(hton)))
  goto err;
 

sql/sql_show.cc

@@ -9942,6 +9942,7 @@ ST_SCHEMA_TABLE schema_tables[]=
 int initialize_schema_table(st_plugin_int *plugin)
 {
  ST_SCHEMA_TABLE *schema_table;
+ int err;
  DBUG_ENTER("initialize_schema_table");
 
  if (!(schema_table= (ST_SCHEMA_TABLE *)my_malloc(key_memory_ST_SCHEMA_TABLE,
@@ -9958,12 +9959,15 @@ int initialize_schema_table(st_plugin_int *plugin)
  /* Make the name available to the init() function. */
  schema_table->table_name= plugin->name.str;
 
- if (plugin->plugin->init(schema_table))
+ if ((err= plugin->plugin->init(schema_table)))
  {
- sql_print_error("Plugin '%s' init function returned error.",
- plugin->name.str);
+ if (err != HA_ERR_RETRY_INIT)
+ sql_print_error("Plugin '%s' init function returned error.",
+ plugin->name.str);
  plugin->data= NULL;
  my_free(schema_table);
+ if (err == HA_ERR_RETRY_INIT)
+ DBUG_RETURN(err);
  DBUG_RETURN(1);
  }
 

storage/spider/mysql-test/spider/bugfix/r/mdev_33538.result

@@ -0,0 +1,12 @@
+show create table information_schema.SPIDER_ALLOC_MEM;
+Table	Create Table
+SPIDER_ALLOC_MEM	CREATE TEMPORARY TABLE `SPIDER_ALLOC_MEM` (
+ `ID` int(10) unsigned NOT NULL,
+ `FUNC_NAME` varchar(64),
+ `FILE_NAME` varchar(64),
+ `LINE_NO` int(10) unsigned,
+ `TOTAL_ALLOC_MEM` bigint(20) unsigned,
+ `CURRENT_ALLOC_MEM` bigint(20),
+ `ALLOC_MEM_COUNT` bigint(20) unsigned,
+ `FREE_MEM_COUNT` bigint(20) unsigned
+) ENGINE=MEMORY DEFAULT CHARSET=utf8 COLLATE=utf8_general_ci

storage/spider/mysql-test/spider/bugfix/r/mdev_33538_fail_init.result

@@ -0,0 +1,8 @@
+call mtr.add_suppression("\\[ERROR\\] SPIDER plugin initialization failed");
+call mtr.add_suppression(".*\\[ERROR\\] Plugin 'SPIDER' registration as a STORAGE ENGINE failed.");
+call mtr.add_suppression(".*\\[ERROR\\] Plugin 'SPIDER_WRAPPER_PROTOCOLS' registration as a INFORMATION SCHEMA failed.");
+call mtr.add_suppression(".*\\[ERROR\\] Plugin 'SPIDER_ALLOC_MEM' registration as a INFORMATION SCHEMA failed.");
+create table mysql.spider_tables (c int);
+# restart: --plugin-load-add=ha_spider
+SELECT * FROM information_schema.SPIDER_ALLOC_MEM;
+ERROR 42S02: Unknown table 'SPIDER_ALLOC_MEM' in information_schema

storage/spider/mysql-test/spider/bugfix/r/plugin_load_add_all.result

@@ -3,5 +3,9 @@
 #
 select * from mysql.plugin;
 name	dl
+select TABLE_NAME from information_schema.TABLES where TABLE_SCHEMA = "information_schema" and TABLE_NAME like "SPIDER_%";
+TABLE_NAME
+SPIDER_ALLOC_MEM
+SPIDER_WRAPPER_PROTOCOLS
 create table t (c int) Engine=SPIDER;
 drop table t;

storage/spider/mysql-test/spider/bugfix/t/mdev_33538.opt

@@ -0,0 +1,2 @@
+--plugin-load-add=ha_spider
+--transaction-read-only=on

storage/spider/mysql-test/spider/bugfix/t/mdev_33538.test

@@ -0,0 +1,2 @@
+# we check that information_schema.SPIDER_ALLOC_MEM exists
+show create table information_schema.SPIDER_ALLOC_MEM;

storage/spider/mysql-test/spider/bugfix/t/mdev_33538_fail_init.test

@@ -0,0 +1,17 @@
+call mtr.add_suppression("\\[ERROR\\] SPIDER plugin initialization failed");
+call mtr.add_suppression(".*\\[ERROR\\] Plugin 'SPIDER' registration as a STORAGE ENGINE failed.");
+call mtr.add_suppression(".*\\[ERROR\\] Plugin 'SPIDER_WRAPPER_PROTOCOLS' registration as a INFORMATION SCHEMA failed.");
+call mtr.add_suppression(".*\\[ERROR\\] Plugin 'SPIDER_ALLOC_MEM' registration as a INFORMATION SCHEMA failed.");
+# We create a table with identical name of the spider system table, to
+# fail the spider init query ([ERROR] SPIDER plugin initialization
+# failed at 'alter table mysql.spider_tables add column if not exists
+# link_id int not null default 0 after table_name, drop primary key,
+# add primary key (db_name, table_name, link_id), algorithm=copy,
+# lock=shared;' by 'Unknown column 'table_name' in 'spider_tables'')
+# This will cause the init of spider_alloc_mem to fail because it
+# depends on the main spider plugin.
+create table mysql.spider_tables (c int);
+--let $restart_parameters= --plugin-load-add=ha_spider
+--source include/restart_mysqld.inc
+--error ER_UNKNOWN_TABLE
+SELECT * FROM information_schema.SPIDER_ALLOC_MEM;

storage/spider/mysql-test/spider/bugfix/t/plugin_load_add_all.test

@@ -3,5 +3,6 @@
 --echo #
 # A simple test that tests plugin-load-add=ha_spider
 select * from mysql.plugin;
+select TABLE_NAME from information_schema.TABLES where TABLE_SCHEMA = "information_schema" and TABLE_NAME like "SPIDER_%";
 create table t (c int) Engine=SPIDER;
 drop table t;

storage/spider/spd_i_s.cc

@@ -129,7 +129,10 @@ static int spider_i_s_alloc_mem_init(
  void *p
 ) {
  ST_SCHEMA_TABLE *schema = (ST_SCHEMA_TABLE *) p;
+ const LEX_CSTRING spider_name={STRING_WITH_LEN("SPIDER")};
  DBUG_ENTER("spider_i_s_alloc_mem_init");
+ if (!plugin_is_ready(&spider_name, MYSQL_STORAGE_ENGINE_PLUGIN))
+ DBUG_RETURN(HA_ERR_RETRY_INIT);
  schema->fields_info = Show::spider_i_s_alloc_mem_fields_info;
  schema->fill_table = spider_i_s_alloc_mem_fill_table;
  schema->idx_field1 = 0;
@@ -249,7 +252,10 @@ static int spider_i_s_wrapper_protocols_init(
  void *p
 ) {
  ST_SCHEMA_TABLE *schema = (ST_SCHEMA_TABLE *) p;
+ const LEX_CSTRING spider_name={STRING_WITH_LEN("SPIDER")};
  DBUG_ENTER("spider_i_s_wrapper_protocols_init");
+ if (!plugin_is_ready(&spider_name, MYSQL_STORAGE_ENGINE_PLUGIN))
+ DBUG_RETURN(HA_ERR_RETRY_INIT);
  schema->fields_info = Show::spider_i_s_wrapper_protocols_fields_info;
  schema->fill_table = spider_i_s_wrapper_protocols_fill_table;
  schema->idx_field1 = 0;