MDEV-35889 set information_schema.system_variables NUMERIC_MIN_VALUE ...

for the innodb_buffer_pool_size system variable based on innodb_page_size. The innodb_buffer_pool_size is dependent on the innodb_page_size. While the minimum is enforced for resizing the minimum isn't exposed by the information_schema.system_variables table. This creates a plugin function plugin_opt_set_limits_by_name that allows plugins to adjust the limits of their system variables during plugin initialization.
MariaDB · Jan 20, 2025 · 5abd367 · 5abd367
1 parent cbb24d9
commit 5abd367
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Showing 4 changed files with 14 additions and 2 deletions.
diff --git a/mysql-test/suite/innodb/t/restart.test b/mysql-test/suite/innodb/t/restart.test
@@ -95,10 +95,11 @@ let $wait_condition =
 
 --disable_cursor_protocol
 SELECT @@innodb_buffer_pool_size INTO @innodb_buffer_pool_size_orig;
-SELECT CEILING((256 + 64) * @@innodb_page_size / 1048576) * 1048576 INTO @min_pool_size;
+SELECT CAST(NUMERIC_MIN_VALUE AS UNSIGNED) INTO @min_pool_size FROM information_schema.system_variables WHERE variable_name='INNODB_BUFFER_POOL_SIZE';
+SET @out_of_bounds_pool_size=@min_pool_size - @@innodb_buffer_pool_chunk_size;
 --enable_cursor_protocol
 --error ER_WRONG_VALUE_FOR_VAR
-EXECUTE IMMEDIATE 'SET GLOBAL innodb_buffer_pool_size = ?' USING (@min_pool_size -1);
+EXECUTE IMMEDIATE 'SET GLOBAL innodb_buffer_pool_size = ?' USING (@out_of_bounds_pool_size);
 
 SHOW WARNINGS;
 

diff --git a/sql/sql_plugin.cc b/sql/sql_plugin.cc
@@ -3804,6 +3804,14 @@ void plugin_opt_set_limits(struct my_option *options,
     options->arg_type= OPT_ARG;
 }
 
+
+void plugin_opt_set_limits_by_name(const char *name, size_t name_len,
+                                   const struct st_mysql_sys_var *opt)
+{
+  sys_var *sv= intern_find_sys_var(name, name_len);
+  if (sv)
+    plugin_opt_set_limits(&sv->option, opt);
+}
 /**
   Creates a set of my_option objects associated with a specified plugin-
   handle.

diff --git a/sql/sql_plugin.h b/sql/sql_plugin.h
@@ -182,6 +182,8 @@ extern void plugin_thdvar_init(THD *thd);
 extern void plugin_thdvar_cleanup(THD *thd);
 sys_var *find_plugin_sysvar(st_plugin_int *plugin, st_mysql_sys_var *var);
 void plugin_opt_set_limits(struct my_option *, const struct st_mysql_sys_var *);
+void plugin_opt_set_limits_by_name(const char *, size_t,
+                                   const struct st_mysql_sys_var *);
 extern SHOW_COMP_OPTION plugin_status(const char *name, size_t len, int type);
 extern bool check_valid_path(const char *path, size_t length);
 extern void plugin_mutex_init();

diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
@@ -3547,6 +3547,7 @@ static int innodb_init_params()
 	/* The buffer pool needs to be able to accommodate enough many
 	pages, even for larger pages */
 	MYSQL_SYSVAR_NAME(buffer_pool_size).min_val= min_buffer_pool_size();
+	plugin_opt_set_limits_by_name(STRING_WITH_LEN("innodb_buffer_pool_size"), (struct st_mysql_sys_var *) &mysql_sysvar_buffer_pool_size);
 
 	if (innobase_buffer_pool_size < MYSQL_SYSVAR_NAME(buffer_pool_size).min_val) {
 		ib::error() << "innodb_page_size="