Backport of:

------------------------------------------------------------
revno: 2630.4.16
committer: Dmitry Lenev <dlenev@mysql.com>
branch nick: mysql-6.0-3726-w
timestamp: Thu 2008-05-29 09:45:02 +0400
message:
  WL#3726 "DDL locking for all metadata objects".

  After review changes in progress.

  Tweaked some comments and did some renames to
  avoid ambiguites.


sql/mysql_priv.h:
  Removed name_lock_locked_table() function.
sql/sql_base.cc:
  Got rid of name_lock_locked_table() function after replacing
  the only call to it with its body.
  Simplified open_table() code by making "action" argument
  mandatory (i.e. one now should always pass non-0 pointer
  in this argument).
  Renamed TABLE_LIST::open_table_type to open_type to
  avoid confusing it with type of table.
  Adjusted comments according to review.
sql/sql_handler.cc:
  Added comment clarifying in which cases we can have TABLE::mdl_lock
  set to 0.
sql/sql_insert.cc:
  Now the 4th argument of open_table() is mandatory (it makes
  no sense to complicate open_table() code when we can simply
  pass dummy variable).
sql/sql_parse.cc:
  Renamed TABLE_LIST::open_table_type to open_type to
  avoid confusing it with type of table.
sql/sql_prepare.cc:
  Renamed TABLE_LIST::open_table_type to open_type to
  avoid confusing it with type of table.
sql/sql_table.cc:
  Now the 4th argument of open_table() is mandatory (it makes
  no sense to complicate open_table() code when we can simply
  pass dummy variable).
sql/sql_trigger.cc:
  Replaced the only call to name_lock_locked_table() function
  with its body.
sql/sql_view.cc:
  Renamed TABLE_LIST::open_table_type to open_type to
  avoid confusing it with type of table.
sql/table.h:
  Renamed TABLE_LIST::open_table_type to open_type (to
  avoid confusing it with type of table) and improved
  comments describing this member.

1 files changed, 10 insertions, 1 deletions

diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index a7a4d48b593..4e2b77292d8 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -446,8 +446,17 @@ bool mysql_create_or_drop_trigger(THD *thd, TABLE_LIST *tables, bool create)
 
   if (thd->locked_tables)
   {
-    if (name_lock_locked_table(thd, tables))
+    /* Under LOCK TABLES we must only accept write locked tables. */
+    if (!(tables->table= find_write_locked_table(thd->open_tables, tables->db,
+                                                 tables->table_name)))
       goto end;
+    /*
+      Ensure that table is opened only by this thread and that no other
+      statement will open this table.
+    */
+    if (wait_while_table_is_used(thd, tables->table, HA_EXTRA_FORCE_REOPEN))
+      goto end;
+
     pthread_mutex_lock(&LOCK_open);
   }
   else