From a3c6001751c887b2edf3ea000322681680eab45d Mon Sep 17 00:00:00 2001
From: heikki <Unknown>
Date: Thu, 31 Aug 2006 19:52:25 +0000
Subject: [PATCH] Fix bug #21784 of a crash in DROP TABLE with concurrent
queries on the table
---
handler/ha_innodb.cc | 33 ++++++++++++++++++++-------------
1 file changed, 20 insertions(+), 13 deletions(-)
diff --git a/handler/ha_innodb.cc b/handler/ha_innodb.cc
index ec79ddfef99..03cc4964681 100644
--- a/handler/ha_innodb.cc
+++ b/handler/ha_innodb.cc
@@ -6789,19 +6789,17 @@ ha_innobase::store_lock(
row_prebuilt_t* prebuilt = (row_prebuilt_t*) innobase_prebuilt;
trx_t* trx;
- /* Call update_thd() to update prebuilt->trx to point to the trx
- object of thd! Failure to do this caused a serious memory
- corruption bug in 5.1.11. */
+ /* Note that trx in this function is NOT necessarily prebuilt->trx
+ because we call update_thd() later, in ::external_lock()! Failure to
+ understand this caused a serious memory corruption bug in 5.1.11. */
- update_thd(thd);
+ trx = check_trx_exists(thd);
- trx = prebuilt->trx;
-
- /* NOTE: MySQL can call this function with lock 'type' TL_IGNORE!
+ /* NOTE: MySQL can call this function with lock 'type' TL_IGNORE!
Be careful to ignore TL_IGNORE if we are going to do something with
only 'real' locks! */
- /* If no MySQL tables is use we need to set isolation level
+ /* If no MySQL table is in use, we need to set the isolation level
of the transaction. */
if (lock_type != TL_IGNORE
@@ -6811,7 +6809,13 @@ ha_innobase::store_lock(
thd->variables.tx_isolation);
}
- if ((lock_type == TL_READ && thd->in_lock_tables) ||
+ if (thd->lex->sql_command == SQLCOM_DROP_TABLE) {
+
+ /* MySQL calls this function in DROP TABLE though this table
+ handle may belong to another thd that is running a query. Let
+ us in that case skip any changes to the prebuilt struct. */
+
+ } else if ((lock_type == TL_READ && thd->in_lock_tables) ||
(lock_type == TL_READ_HIGH_PRIORITY && thd->in_lock_tables) ||
lock_type == TL_READ_WITH_SHARED_LOCKS ||
lock_type == TL_READ_NO_INSERT ||
@@ -7071,11 +7075,14 @@ ha_innobase::innobase_read_and_init_auto_inc(
in table.h says that 'next_number_field' is set when it is
'active'. */
- auto_inc = (longlong) table->found_next_number_field->
- val_int_offset(table->s->rec_buff_length) + 1;
- }
+ my_bitmap_map *old_map;
+ old_map= dbug_tmp_use_all_columns(table, table->read_set);
+ auto_inc = (longlong) table->found_next_number_field->
+ val_int_offset(table->s->rec_buff_length) + 1;
+ dbug_tmp_restore_column_map(table->read_set, old_map);
+ }
- dict_table_autoinc_initialize(prebuilt->table, auto_inc);
+ dict_table_autoinc_initialize(prebuilt->table, auto_inc);
func_exit:
(void) extra(HA_EXTRA_NO_KEYREAD);