Use less memory on stack in sql_parse.cc and in repair/check for MyISAM & Aria

sql/sql_parse.cc:
  Make some not commonly used functions with big local variables to separate functions to make default stack usage smaller.
  Decrease size of db_buff[] (Was bigger than needed)
  Allocate current_global_status_var with malloc().
storage/maria/ha_maria.cc:
  Don't allocate HA_CHECK on stack (it's > 100K)
storage/maria/ma_check.c:
  Removed duplicated code

sql/sql_parse.cc

@@ -48,6 +48,9 @@
    "FUNCTION" : "PROCEDURE")
 
 static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables);
+static bool execute_show_status(THD *thd, TABLE_LIST *all_tables);
+static bool execute_rename_table(THD *thd, TABLE_LIST *first_table,
+                                 TABLE_LIST *all_tables);
 static bool check_show_create_table_access(THD *thd, TABLE_LIST *table);
 
 const char *any_db="*any*";	// Special symbol for check_access
@@ -1125,7 +1128,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       Cast *passwd to an unsigned char, so that it doesn't extend the sign
       for *passwd > 127 and become 2**32-127 after casting to uint.
     */
-    char db_buff[SAFE_NAME_LEN*2+1];           // buffer to store db in utf8
+    char db_buff[SAFE_NAME_LEN+1];           // buffer to store db in utf8
     char *db= passwd;
     char *save_db;
     /*
@@ -1556,7 +1559,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
 #endif
   case COM_STATISTICS:
   {
-    STATUS_VAR current_global_status_var;
+    STATUS_VAR *current_global_status_var;      // Big; Don't allocate on stack
     ulong uptime;
 #if defined(SAFEMALLOC) || !defined(EMBEDDED_LIBRARY)
     uint length;
@@ -1565,9 +1568,12 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     char buff[250];
     uint buff_len= sizeof(buff);
 
+    if (!(current_global_status_var= (STATUS_VAR*)
+          thd->alloc(sizeof(STATUS_VAR))))
+      break;
     general_log_print(thd, command, NullS);
     status_var_increment(thd->status_var.com_stat[SQLCOM_SHOW_STATUS]);
-    calc_sum_of_all_status(&current_global_status_var);
+    calc_sum_of_all_status(current_global_status_var);
     if (!(uptime= (ulong) (thd->start_time - server_start_time)))
       queries_per_second1000= 0;
     else
@@ -1582,8 +1588,8 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
                   "Open tables: %u  Queries per second avg: %u.%u",
                   uptime,
                   (int) thread_count, (ulong) thd->query_id,
-                  current_global_status_var.long_query_count,
-                  current_global_status_var.opened_tables,
+                  current_global_status_var->long_query_count,
+                  current_global_status_var->opened_tables,
                   refresh_version,
                   cached_open_tables(),
                   (uint) (queries_per_second1000 / 1000),
@@ -2285,22 +2291,7 @@ mysql_execute_command(THD *thd)
     break;
   case SQLCOM_SHOW_STATUS:
   {
-    system_status_var old_status_var= thd->status_var;
-    thd->initial_status_var= &old_status_var;
-    if (!(res= check_table_access(thd, SELECT_ACL, all_tables, UINT_MAX, FALSE)))
-      res= execute_sqlcom_select(thd, all_tables);
-    /* Don't log SHOW STATUS commands to slow query log */
-    thd->server_status&= ~(SERVER_QUERY_NO_INDEX_USED |
-                           SERVER_QUERY_NO_GOOD_INDEX_USED);
-    /*
-      restore status variables, as we don't want 'show status' to cause
-      changes
-    */
-    pthread_mutex_lock(&LOCK_status);
-    add_diff_to_status(&global_status_var, &thd->status_var,
-                       &old_status_var);
-    thd->status_var= old_status_var;
-    pthread_mutex_unlock(&LOCK_status);
+    execute_show_status(thd, all_tables);
     break;
   }
   case SQLCOM_SHOW_DATABASES:
@@ -3005,31 +2996,7 @@ end_with_restore_list:
     }
   case SQLCOM_RENAME_TABLE:
   {
-    DBUG_ASSERT(first_table == all_tables && first_table != 0);
-    TABLE_LIST *table;
-    for (table= first_table; table; table= table->next_local->next_local)
-    {
-      if (check_access(thd, ALTER_ACL | DROP_ACL, table->db,
-		       &table->grant.privilege,0,0, test(table->schema_table)) ||
-	  check_access(thd, INSERT_ACL | CREATE_ACL, table->next_local->db,
-		       &table->next_local->grant.privilege, 0, 0,
-                       test(table->next_local->schema_table)))
-	goto error;
-      TABLE_LIST old_list, new_list;
-      /*
-        we do not need initialize old_list and new_list because we will
-        come table[0] and table->next[0] there
-      */
-      old_list= table[0];
-      new_list= table->next_local[0];
-      if (check_grant(thd, ALTER_ACL | DROP_ACL, &old_list, 0, 1, 0) ||
-         (!test_all_bits(table->next_local->grant.privilege,
-                         INSERT_ACL | CREATE_ACL) &&
-          check_grant(thd, INSERT_ACL | CREATE_ACL, &new_list, 0, 1, 0)))
-        goto error;
-    }
-
-    if (end_active_trans(thd) || mysql_rename_tables(thd, first_table, 0))
+    if (execute_rename_table(thd, first_table, all_tables))
       goto error;
     break;
   }
@@ -5172,6 +5139,62 @@ static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables)
 }
 
 
+static bool execute_show_status(THD *thd, TABLE_LIST *all_tables)
+{
+  bool res;
+  system_status_var old_status_var= thd->status_var;
+  thd->initial_status_var= &old_status_var;
+  if (!(res= check_table_access(thd, SELECT_ACL, all_tables, UINT_MAX, FALSE)))
+    res= execute_sqlcom_select(thd, all_tables);
+  /* Don't log SHOW STATUS commands to slow query log */
+  thd->server_status&= ~(SERVER_QUERY_NO_INDEX_USED |
+                         SERVER_QUERY_NO_GOOD_INDEX_USED);
+  /*
+    restore status variables, as we don't want 'show status' to cause
+    changes
+  */
+  pthread_mutex_lock(&LOCK_status);
+  add_diff_to_status(&global_status_var, &thd->status_var,
+                     &old_status_var);
+  thd->status_var= old_status_var;
+  pthread_mutex_unlock(&LOCK_status);
+  return res;
+}
+
+
+static bool execute_rename_table(THD *thd, TABLE_LIST *first_table,
+                                 TABLE_LIST *all_tables)
+{
+  DBUG_ASSERT(first_table == all_tables && first_table != 0);
+  TABLE_LIST *table;
+  for (table= first_table; table; table= table->next_local->next_local)
+  {
+    if (check_access(thd, ALTER_ACL | DROP_ACL, table->db,
+                     &table->grant.privilege,0,0, test(table->schema_table)) ||
+        check_access(thd, INSERT_ACL | CREATE_ACL, table->next_local->db,
+                     &table->next_local->grant.privilege, 0, 0,
+                     test(table->next_local->schema_table)))
+      return 1;
+    TABLE_LIST old_list, new_list;
+    /*
+      we do not need initialize old_list and new_list because we will
+      come table[0] and table->next[0] there
+    */
+    old_list= table[0];
+    new_list= table->next_local[0];
+    if (check_grant(thd, ALTER_ACL | DROP_ACL, &old_list, 0, 1, 0) ||
+        (!test_all_bits(table->next_local->grant.privilege,
+                        INSERT_ACL | CREATE_ACL) &&
+         check_grant(thd, INSERT_ACL | CREATE_ACL, &new_list, 0, 1, 0)))
+      return 1;
+  }
+
+  if (end_active_trans(thd) || mysql_rename_tables(thd, first_table, 0))
+    return 1;
+  return 0;
+}
+
+
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
 /**
   Check grants for commands which work only with one table.

storage/maria/ha_maria.cc

@@ -1043,14 +1043,14 @@ int ha_maria::write_row(uchar * buf)
 
 int ha_maria::check(THD * thd, HA_CHECK_OPT * check_opt)
 {
-  if (!file)
-    return HA_ADMIN_INTERNAL_ERROR;
   int error;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
   MARIA_SHARE *share= file->s;
   const char *old_proc_info= thd_proc_info(thd, "Checking table");
   TRN *old_trn= file->trn;
 
+  if (!file || !&param) return HA_ADMIN_INTERNAL_ERROR;
+
   maria_chk_init(&param);
   param.thd= thd;
   param.op_name= "check";
@@ -1144,9 +1144,12 @@ int ha_maria::check(THD * thd, HA_CHECK_OPT * check_opt)
 int ha_maria::analyze(THD *thd, HA_CHECK_OPT * check_opt)
 {
   int error= 0;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
   MARIA_SHARE *share= file->s;
 
+  if (!&param)
+    return HA_ADMIN_INTERNAL_ERROR;
+
   maria_chk_init(&param);
   param.thd= thd;
   param.op_name= "analyze";
@@ -1281,7 +1284,10 @@ int ha_maria::backup(THD * thd, HA_CHECK_OPT *check_opt)
 
 err:
   {
-    HA_CHECK param;
+    HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
+    if (!&param)
+      return HA_ADMIN_INTERNAL_ERROR;
+
     maria_chk_init(&param);
     param.thd= thd;
     param.op_name= "backup";
@@ -1297,10 +1303,10 @@ err:
 int ha_maria::repair(THD * thd, HA_CHECK_OPT *check_opt)
 {
   int error;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
   ha_rows start_records;
 
-  if (!file)
+  if (!file || !&param)
     return HA_ADMIN_INTERNAL_ERROR;
 
   maria_chk_init(&param);
@@ -1352,11 +1358,11 @@ int ha_maria::repair(THD * thd, HA_CHECK_OPT *check_opt)
 int ha_maria::zerofill(THD * thd, HA_CHECK_OPT *check_opt)
 {
   int error;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
   TRN *old_trn;
   MARIA_SHARE *share= file->s;
 
-  if (!file)
+  if (!file || !&param)
     return HA_ADMIN_INTERNAL_ERROR;
 
   old_trn= file->trn;
@@ -1382,9 +1388,9 @@ int ha_maria::zerofill(THD * thd, HA_CHECK_OPT *check_opt)
 int ha_maria::optimize(THD * thd, HA_CHECK_OPT *check_opt)
 {
   int error;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
 
-  if (!file)
+  if (!file || !&param)
     return HA_ADMIN_INTERNAL_ERROR;
 
   maria_chk_init(&param);
@@ -1623,7 +1629,10 @@ int ha_maria::assign_to_keycache(THD * thd, HA_CHECK_OPT *check_opt)
   if (error != HA_ADMIN_OK)
   {
     /* Send error to user */
-    HA_CHECK param;
+    HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
+    if (!&param)
+      return HA_ADMIN_INTERNAL_ERROR;
+
     maria_chk_init(&param);
     param.thd= thd;
     param.op_name= "assign_to_keycache";
@@ -1684,7 +1693,10 @@ int ha_maria::preload_keys(THD * thd, HA_CHECK_OPT *check_opt)
       errmsg= buf;
     }
 
-    HA_CHECK param;
+    HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
+    if (!&param)
+      return HA_ADMIN_INTERNAL_ERROR;
+
     maria_chk_init(&param);
     param.thd= thd;
     param.op_name= "preload_keys";
@@ -1792,8 +1804,12 @@ int ha_maria::enable_indexes(uint mode)
   else if (mode == HA_KEY_SWITCH_NONUNIQ_SAVE)
   {
     THD *thd= current_thd;
-    HA_CHECK param;
+    HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
+    if (!&param)
+      return HA_ADMIN_INTERNAL_ERROR;
+
     const char *save_proc_info= thd_proc_info(thd, "Creating index");
+
     maria_chk_init(&param);
     param.op_name= "recreating_index";
     param.testflag= (T_SILENT | T_REP_BY_SORT | T_QUICK |

storage/maria/ma_check.c

@@ -4409,8 +4409,7 @@ int maria_repair_parallel(HA_CHECK *param, register MARIA_HA *info,
         goto err;
       }
     }
-    share->state.state.data_file_length= share->state.state.data_file_length=
-      sort_param->filepos;
+    share->state.state.data_file_length= sort_param->filepos;
     /* Only whole records */
     share->state.version= (ulong) time((time_t*) 0);
     /*

storage/myisam/ha_myisam.cc

@@ -799,10 +799,13 @@ int ha_myisam::check(THD* thd, HA_CHECK_OPT* check_opt)
 {
   if (!file) return HA_ADMIN_INTERNAL_ERROR;
   int error;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
   MYISAM_SHARE* share = file->s;
   const char *old_proc_info=thd->proc_info;
 
+  if (!&param)
+    return HA_ADMIN_INTERNAL_ERROR;
+
   thd_proc_info(thd, "Checking table");
   myisamchk_init(&param);
   param.thd = thd;
@@ -891,9 +894,12 @@ int ha_myisam::check(THD* thd, HA_CHECK_OPT* check_opt)
 int ha_myisam::analyze(THD *thd, HA_CHECK_OPT* check_opt)
 {
   int error=0;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
   MYISAM_SHARE* share = file->s;
 
+  if (!&param)
+    return HA_ADMIN_INTERNAL_ERROR;
+
   myisamchk_init(&param);
   param.thd = thd;
   param.op_name=    "analyze";
@@ -1021,7 +1027,9 @@ int ha_myisam::backup(THD* thd, HA_CHECK_OPT *check_opt)
 
  err:
   {
-    HA_CHECK param;
+    HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
+    if (!&param)
+      return HA_ADMIN_INTERNAL_ERROR;
     myisamchk_init(&param);
     param.thd=        thd;
     param.op_name=    "backup";
@@ -1037,10 +1045,10 @@ int ha_myisam::backup(THD* thd, HA_CHECK_OPT *check_opt)
 int ha_myisam::repair(THD* thd, HA_CHECK_OPT *check_opt)
 {
   int error;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
   ha_rows start_records;
 
-  if (!file) return HA_ADMIN_INTERNAL_ERROR;
+  if (!file || !&param) return HA_ADMIN_INTERNAL_ERROR;
 
   myisamchk_init(&param);
   param.thd = thd;
@@ -1088,8 +1096,9 @@ int ha_myisam::repair(THD* thd, HA_CHECK_OPT *check_opt)
 int ha_myisam::optimize(THD* thd, HA_CHECK_OPT *check_opt)
 {
   int error;
-  if (!file) return HA_ADMIN_INTERNAL_ERROR;
-  HA_CHECK param;
+  HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
+
+  if (!file || !&param) return HA_ADMIN_INTERNAL_ERROR;
 
   myisamchk_init(&param);
   param.thd = thd;
@@ -1283,7 +1292,10 @@ int ha_myisam::assign_to_keycache(THD* thd, HA_CHECK_OPT *check_opt)
   if (error != HA_ADMIN_OK)
   {
     /* Send error to user */
-    HA_CHECK param;
+    HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
+    if (!&param)
+      return HA_ADMIN_INTERNAL_ERROR;
+
     myisamchk_init(&param);
     param.thd= thd;
     param.op_name=    "assign_to_keycache";
@@ -1347,7 +1359,9 @@ int ha_myisam::preload_keys(THD* thd, HA_CHECK_OPT *check_opt)
 
  err:
   {
-    HA_CHECK param;
+    HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
+    if (!&param)
+      return HA_ADMIN_INTERNAL_ERROR;
     myisamchk_init(&param);
     param.thd= thd;
     param.op_name=    "preload_keys";
@@ -1457,8 +1471,12 @@ int ha_myisam::enable_indexes(uint mode)
   else if (mode == HA_KEY_SWITCH_NONUNIQ_SAVE)
   {
     THD *thd=current_thd;
-    HA_CHECK param;
+    HA_CHECK &param= *(HA_CHECK*) thd->alloc(sizeof(param));
     const char *save_proc_info=thd->proc_info;
+
+    if (!&param)
+      return HA_ADMIN_INTERNAL_ERROR;
+
     thd_proc_info(thd, "Creating index");
     myisamchk_init(&param);
     param.op_name= "recreating_index";