Commit 4ec0f6ce authored by thek@adventure.(none)'s avatar thek@adventure.(none)
Browse files

Bug#24988 FLUSH PRIVILEGES causes brief unavailability 

- A race condition caused brief unavailablility when trying to acccess
  a table.
- The unprotected variable 'grant_option' wasn't intended to alternate
  during normal execution. Variable initialization moved to grant_init
  a lines responsible for the alternation are removed.
parent 6d6674e7

sql/mysqld.cc

+9 −1
Original line number Diff line number Diff line
@@ -346,7 +346,15 @@ bool opt_endinfo, using_udf_functions; 
my_bool locked_in_memory;

bool opt_using_transactions, using_update_log;

bool volatile abort_loop;

bool volatile shutdown_in_progress, grant_option;

bool volatile shutdown_in_progress;

/**

   @brief 'grant_option' is used to indicate if privileges needs

   to be checked, in which case the lock, LOCK_grant, is used

   to protect access to the grant table.

   @note This flag is dropped in 5.1 

   @see grant_init()

 */

bool volatile grant_option;



my_bool opt_skip_slave_start = 0; // If set, slave is not autostarted

my_bool opt_reckless_slave = 0;

sql/sql_acl.cc

+4 −7
Original line number Diff line number Diff line
@@ -2995,7 +2995,7 @@ bool mysql_table_grant(THD *thd, TABLE_LIST *table_list, 
      }

    }

  }

  grant_option=TRUE;

  

  thd->mem_root= old_root;

  pthread_mutex_unlock(&acl_cache->lock);
@@ -3162,7 +3162,7 @@ bool mysql_routine_grant(THD *thd, TABLE_LIST *table_list, bool is_proc, 
      continue;

    }

  }

  grant_option=TRUE;

  

  thd->mem_root= old_root;

  pthread_mutex_unlock(&acl_cache->lock);

  if (!result && !no_error)
@@ -3338,6 +3338,8 @@ my_bool grant_init() 
  delete thd;

  /* Remember that we don't have a THD */

  my_pthread_setspecific_ptr(THR_THD,  0);

  /* Set the grant option flag so we will check grants */

  grant_option= TRUE;

  DBUG_RETURN(return_val);

}
@@ -3367,7 +3369,6 @@ static my_bool grant_load(TABLE_LIST *tables) 
                                                           THR_MALLOC);

  DBUG_ENTER("grant_load");



  grant_option = FALSE;

  (void) hash_init(&column_priv_hash,system_charset_info,

		   0,0,0, (hash_get_key) get_grant_table,

		   (hash_free_key) free_grant_table,0);
@@ -3478,7 +3479,6 @@ static my_bool grant_load(TABLE_LIST *tables) 
    }

    while (!p_table->file->index_next(p_table->record[0]));

  }

  grant_option= TRUE;

  return_val=0;					// Return ok



end_unlock:
@@ -3511,7 +3511,6 @@ my_bool grant_reload(THD *thd) 
{

  TABLE_LIST tables[3];

  HASH old_column_priv_hash, old_proc_priv_hash, old_func_priv_hash;

  bool old_grant_option;

  MEM_ROOT old_mem;

  my_bool return_val= 1;

  DBUG_ENTER("grant_reload");
@@ -3541,7 +3540,6 @@ my_bool grant_reload(THD *thd) 
  old_column_priv_hash= column_priv_hash;

  old_proc_priv_hash= proc_priv_hash;

  old_func_priv_hash= func_priv_hash;

  old_grant_option= grant_option;

  old_mem= memex;



  if ((return_val= grant_load(tables)))
@@ -3551,7 +3549,6 @@ my_bool grant_reload(THD *thd) 
    column_priv_hash= old_column_priv_hash;	/* purecov: deadcode */

    proc_priv_hash= old_proc_priv_hash;

    func_priv_hash= old_func_priv_hash;

    grant_option= old_grant_option;		/* purecov: deadcode */

    memex= old_mem;				/* purecov: deadcode */

  }

  else