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From:Magne Mahre Date:January 13 2009 11:50am
Subject:bzr commit into mysql-6.0-runtime branch (magne.mahre:2783) Bug#37433
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#At file:///export/home/tmp/z/mysql-6.0-runtime-fix37433/ based on revid:magne.mahre@stripped

 2783 Magne Mahre	2009-01-13
      Bug #37433  	Deadlock between open_table, close_open_tables, 
                      get_table_share, drop_open_table
      In the partition handler code, LOCK_open and share->LOCK_ha_data
      are acquired in the wrong order in certain cases.  When doing a
      multi-row INSERT (i.e a INSERT..SELECT) in a table with auto-
      increment column(s). the increments must be in a monotonically
      continuous increasing sequence (i.e it can't have "holes"). To
      achieve this, a lock is held for the duration of the operation.
      share->LOCK_ha_data was used for this purpose.
      Whenever there was a need to open a view _during_ the operation
      (views are not currently pre-opened the way tables are), and
      LOCK_open was grabbed, a deadlock could occur.  share->LOCK_ha_data
      is other places used _while_ holding LOCK_open.
      A new mutex was introduced in the HA_DATA_PARTITION structure,
      for exclusive use of the autoincrement data fields, so we don't
      need to overload the use of LOCK_ha_data here.
      A module test case has not been supplied, since the problem occurs
      as a result of a race condition, and testing for this condition 
      is thus not deterministic.   Testing for it could be done by
      setting up a test case as described in the bug report.

=== modified file 'sql/'

=== modified file 'sql/'
--- a/sql/	2008-11-24 22:54:28 +0000
+++ b/sql/	2009-01-13 11:50:40 +0000
@@ -2528,6 +2528,7 @@
     DBUG_PRINT("info", ("table_share->ha_data 0x%p", ha_data));
     bzero(ha_data, sizeof(HA_DATA_PARTITION));
+    pthread_mutex_init(&ha_data->mutex, MY_MUTEX_INIT_FAST);
   if (is_not_tmp_table)

=== modified file 'sql/ha_partition.h'
--- a/sql/ha_partition.h	2008-11-15 00:34:27 +0000
+++ b/sql/ha_partition.h	2009-01-13 11:50:40 +0000
@@ -45,6 +45,7 @@
   ulonglong next_auto_inc_val;                 /**< first non reserved value */
   bool auto_inc_initialized;
+  pthread_mutex_t mutex;                   /* hold while accessing fields */
@@ -908,18 +909,21 @@
   virtual int reset_auto_increment(ulonglong value);
   virtual void lock_auto_increment()
+    HA_DATA_PARTITION *ha_data;
     /* lock already taken */
     if (auto_increment_safe_stmt_log_lock)
     DBUG_ASSERT(table_share->ha_data && !auto_increment_lock);
     if(table_share->tmp_table == NO_TMP_TABLE)
+      ha_data= (HA_DATA_PARTITION*) table_share->ha_data;
       auto_increment_lock= TRUE;
-      pthread_mutex_lock(&table_share->LOCK_ha_data);
+      pthread_mutex_lock(&ha_data->mutex);
   virtual void unlock_auto_increment()
+    HA_DATA_PARTITION *ha_data;
       If auto_increment_safe_stmt_log_lock is true, we have to keep the lock.
@@ -928,7 +932,8 @@
     if(auto_increment_lock && !auto_increment_safe_stmt_log_lock)
-      pthread_mutex_unlock(&table_share->LOCK_ha_data);
+      ha_data= (HA_DATA_PARTITION*) table_share->ha_data;
+      pthread_mutex_unlock(&ha_data->mutex);
       auto_increment_lock= FALSE;

bzr commit into mysql-6.0-runtime branch (magne.mahre:2783) Bug#37433Magne Mahre13 Jan
  • Re: bzr commit into mysql-6.0-runtime branch (magne.mahre:2783)Bug#37433Mattias Jonsson18 Feb