Bug#42643: InnoDB does not support replication of TRUNCATE TABLE

The problem was that TRUNCATE TABLE didn't take a exclusive
lock on a table if it resorted to truncating via delete of
all rows in the table. Specifically for InnoDB tables, this
could break proper isolation as InnoDB ends up aborting some
granted locks when truncating a table.

The solution is to take a exclusive metadata lock before
TRUNCATE TABLE can proceed. This guarantees that no other
transaction is using the table.

Incompatible change: Truncate via delete no longer fails
if sql_safe_updates is activated (this was a undocumented
side effect).

libmysqld/CMakeLists.txt:
  Add new files to the build list.
libmysqld/Makefile.am:
  Add new files to the build list.
mysql-test/extra/binlog_tests/binlog_truncate.test:
  Add test case for Bug#42643
mysql-test/include/mix1.inc:
  Update test case as TRUNCATE TABLE now grabs a exclusive lock.
  Ensure that TRUNCATE waits for granted locks on the table.
mysql-test/suite/binlog/t/binlog_truncate_innodb.test:
  As with other data modifying statements, TRUNCATE is still not
  possible in a transaction with isolation level READ COMMITTED
  or READ UNCOMMITED. It would be possible to implement so, but
  it is not worth the effort.
mysql-test/suite/binlog/t/binlog_truncate_myisam.test:
  Test under different binlog formats.
mysql-test/suite/binlog/t/disabled.def:
  Re-enable test case.
mysql-test/t/innodb_bug38231.test:
  Truncate no longer works with row-level locks.
mysql-test/t/mdl_sync.test:
  Ensure that a acquired lock is not given up due to a conflict.
mysql-test/t/partition_innodb_semi_consistent.test:
  End transaction as to release metadata locks.
mysql-test/t/truncate.test:
  A metadata lock is now taken before the object is verified.
sql/CMakeLists.txt:
  Add new files to the build list.
sql/Makefile.am:
  Add new files to the build list.
sql/datadict.cc:
  Introduce a new file specific for data dictionary operations.
sql/datadict.h:
  Add header file.
sql/sql_base.cc:
  Rename data dictionary function.
sql/sql_bitmap.h:
  Include dependency.
sql/sql_delete.cc:
  Move away from relying on mysql_delete() to delete all rows of
  a table. Thus, move any bits related to truncate to sql_truncate.cc
sql/sql_delete.h:
  Remove parameter.
sql/sql_parse.cc:
  Add protection against the global read lock -- a intention
  exclusive lock can be acquired in the truncate path.
sql/sql_show.cc:
  Add sync point for testing scenarios where a pending flush
  is ignored.
sql/sql_truncate.cc:
  Acquire a shared metadata lock before accessing table metadata.
  Upgrade the lock to a exclusive one if the table can be re-created.
  Rework binlog rules to better reflect the requirements.
sql/sql_yacc.yy:
  Set appropriate lock types for table to be truncated.
sql/table.h:
  Move to data dictionary header.

1 files changed, 161 insertions, 0 deletions

diff --git a/sql/datadict.cc b/sql/datadict.cc
new file mode 100644
index 00000000000..5067c13a255
--- /dev/null
+++ b/sql/datadict.cc
@@ -0,0 +1,161 @@
+/* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+#include "datadict.h"
+#include "sql_priv.h"
+#include "sql_class.h"
+#include "sql_table.h"
+
+
+/**
+  Check type of .frm if we are not going to parse it.
+
+  @param  path  path to FRM file
+
+  @retval  FRMTYPE_ERROR        error
+  @retval  FRMTYPE_TABLE        table
+  @retval  FRMTYPE_VIEW         view
+*/
+
+frm_type_enum dd_frm_type(THD *thd, char *path, enum legacy_db_type *dbt)
+{
+  File file;
+  uchar header[10];     //"TYPE=VIEW\n" it is 10 characters
+  size_t error;
+  DBUG_ENTER("dd_frm_type");
+
+  *dbt= DB_TYPE_UNKNOWN;
+
+  if ((file= mysql_file_open(key_file_frm, path, O_RDONLY | O_SHARE, MYF(0))) < 0)
+    DBUG_RETURN(FRMTYPE_ERROR);
+  error= mysql_file_read(file, (uchar*) header, sizeof(header), MYF(MY_NABP));
+  mysql_file_close(file, MYF(MY_WME));
+
+  if (error)
+    DBUG_RETURN(FRMTYPE_ERROR);
+  if (!strncmp((char*) header, "TYPE=VIEW\n", sizeof(header)))
+    DBUG_RETURN(FRMTYPE_VIEW);
+
+  /*
+    This is just a check for DB_TYPE. We'll return default unknown type
+    if the following test is true (arg #3). This should not have effect
+    on return value from this function (default FRMTYPE_TABLE)
+  */
+  if (header[0] != (uchar) 254 || header[1] != 1 ||
+      (header[2] != FRM_VER && header[2] != FRM_VER+1 &&
+       (header[2] < FRM_VER+3 || header[2] > FRM_VER+4)))
+    DBUG_RETURN(FRMTYPE_TABLE);
+
+  *dbt= (enum legacy_db_type) (uint) *(header + 3);
+
+  /* Probably a table. */
+  DBUG_RETURN(FRMTYPE_TABLE);
+}
+
+
+/**
+  Given a table name, check if the storage engine for the
+  table referred by this name supports an option 'flag'.
+  Return an error if the table does not exist or is not a
+  base table.
+
+  @pre Any metadata lock on the table.
+
+  @param[in]    thd         The current session.
+  @param[in]    db          Table schema.
+  @param[in]    table_name  Table database.
+  @param[in]    flag        The option to check.
+  @param[out]   yes_no      The result. Undefined if error.
+*/
+
+bool dd_check_storage_engine_flag(THD *thd,
+                                  const char *db, const char *table_name,
+                                  uint32 flag, bool *yes_no)
+{
+  char path[FN_REFLEN + 1];
+  enum legacy_db_type db_type;
+  handlerton *table_type;
+  LEX_STRING db_name = {(char *) db, strlen(db)};
+
+  if (check_db_name(&db_name))
+  {
+    my_error(ER_WRONG_DB_NAME, MYF(0), db_name.str);
+    return TRUE;
+  }
+
+  if (check_table_name(table_name, strlen(table_name)))
+  {
+    my_error(ER_WRONG_TABLE_NAME, MYF(0), table_name);
+    return TRUE;
+  }
+
+  /* There should be at least some lock on the table.  */
+  DBUG_ASSERT(thd->mdl_context.is_lock_owner(MDL_key::TABLE, db,
+                                             table_name, MDL_SHARED));
+
+  (void) build_table_filename(path, sizeof(path) - 1, db,
+                              table_name, reg_ext, 0);
+
+  dd_frm_type(thd, path, &db_type);
+
+  /* Type is unknown if the object is not found or is not a table. */
+  if (db_type == DB_TYPE_UNKNOWN)
+  {
+    my_error(ER_NO_SUCH_TABLE, MYF(0), db, table_name);
+    return TRUE;
+  }
+
+  table_type= ha_resolve_by_legacy_type(thd, db_type);
+  *yes_no= ha_check_storage_engine_flag(table_type, flag);
+
+  return FALSE;
+}
+
+
+/*
+  Regenerate a metadata locked table.
+
+  @param  thd   Thread context.
+  @param  db    Name of the database to which the table belongs to.
+  @param  name  Table name.
+
+  @retval  FALSE  Success.
+  @retval  TRUE   Error.
+*/
+
+bool dd_recreate_table(THD *thd, const char *db, const char *table_name)
+{
+  bool error= TRUE;
+  HA_CREATE_INFO create_info;
+  char path[FN_REFLEN + 1];
+  DBUG_ENTER("dd_recreate_table");
+
+  /* There should be a exclusive metadata lock on the table. */
+  DBUG_ASSERT(thd->mdl_context.is_lock_owner(MDL_key::TABLE, db, table_name,
+                                             MDL_EXCLUSIVE));
+
+  memset(&create_info, 0, sizeof(create_info));
+
+  /* Create a path to the table, but without a extension. */
+  build_table_filename(path, sizeof(path) - 1, db, table_name, "", 0);
+
+  /* Attempt to reconstruct the table. */
+  mysql_mutex_lock(&LOCK_open);
+  error= ha_create_table(thd, path, db, table_name, &create_info, TRUE);
+  mysql_mutex_unlock(&LOCK_open);
+
+  DBUG_RETURN(error);
+}
+