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Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash

Version for 5.0.
It fixes three problems:
1. The cause of the bug was that we did not check the table version for
 the HANDLER ... READ commands. We did not notice when a table was
 replaced by a new one. This can happen during ALTER TABLE, REPAIR
 TABLE, and OPTIMIZE TABLE (there might be more cases). I call the fix
 for this problem "the primary bug fix".
2. mysql_ha_flush() was not always called with a locked LOCK_open.
 Though the function comment clearly said it must.
 I changed the code so that the locking is done when required. I call
 the fix for this problem "the secondary fix".
3. In 5.0 (not in 4.1 or 4.0) DROP TABLE had a possible deadlock flaw in
 concur with FLUSH TABLES WITH READ LOCK. I call the fix for this
 problem "the 5.0 addendum fix".


include/my_pthread.h:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  Added a new macro for the 5.0 addendum fix.
mysql-test/r/handler.result:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  The test result.
mysql-test/t/handler.test:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  The test case.
sql/lock.cc:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  Changed a comment which did confuse me and which is not fully
  correct anymore after the 5.0 addendum fix.
  Added an assertion which would fire without the 5.0 addendum fix.
sql/mysql_priv.h:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  Changed a definition for the secondary fix.
sql/sql_base.cc:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  Changed function calls for the secondary fix.
sql/sql_class.cc:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  Changed a function call for the secondary fix.
sql/sql_handler.cc:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  The first two diffs make the primary bug fix.
  The rest is for the secondary fix.
sql/sql_table.cc:
  Bug#14397 - OPTIMIZE TABLE with an open HANDLER causes a crash
  The first diff (four changed places) make the 5.0 addendum fix.
  The other three are changed function calls for the secondary fix.
This commit is contained in:
unknown
2005-11-15 21:57:02 +01:00
parent d9c7aaf23f
commit 013b3d8ab3
9 changed files with 200 additions and 23 deletions

View File

@ -336,6 +336,7 @@ bool mysql_ha_read(THD *thd, TABLE_LIST *tables,
ha_rows select_limit_cnt, ha_rows offset_limit_cnt)
{
TABLE_LIST *hash_tables;
TABLE **table_ptr;
TABLE *table;
MYSQL_LOCK *lock;
List<Item> list;
@ -368,6 +369,28 @@ bool mysql_ha_read(THD *thd, TABLE_LIST *tables,
DBUG_PRINT("info-in-hash",("'%s'.'%s' as '%s' tab %p",
hash_tables->db, hash_tables->table_name,
hash_tables->alias, table));
/* Table might have been flushed. */
if (table && (table->s->version != refresh_version))
{
/*
We must follow the thd->handler_tables chain, as we need the
address of the 'next' pointer referencing this table
for close_thread_table().
*/
for (table_ptr= &(thd->handler_tables);
*table_ptr && (*table_ptr != table);
table_ptr= &(*table_ptr)->next)
{}
(*table_ptr)->file->ha_index_or_rnd_end();
VOID(pthread_mutex_lock(&LOCK_open));
if (close_thread_table(thd, table_ptr))
{
/* Tell threads waiting for refresh that something has happened */
VOID(pthread_cond_broadcast(&COND_refresh));
}
VOID(pthread_mutex_unlock(&LOCK_open));
table= hash_tables->table= NULL;
}
if (!table)
{
/*
@ -594,6 +617,7 @@ err0:
MYSQL_HA_REOPEN_ON_USAGE mark for reopen.
MYSQL_HA_FLUSH_ALL flush all tables, not only
those marked for flush.
is_locked If LOCK_open is locked.
DESCRIPTION
The list of HANDLER tables may be NULL, in which case all HANDLER
@ -601,7 +625,6 @@ err0:
If 'tables' is NULL and MYSQL_HA_FLUSH_ALL is not set,
all HANDLER tables marked for flush are closed.
Broadcasts a COND_refresh condition, for every table closed.
The caller must lock LOCK_open.
NOTE
Since mysql_ha_flush() is called when the base table has to be closed,
@ -611,10 +634,12 @@ err0:
0 ok
*/
int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags)
int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags,
bool is_locked)
{
TABLE_LIST *tmp_tables;
TABLE **table_ptr;
bool did_lock= FALSE;
DBUG_ENTER("mysql_ha_flush");
DBUG_PRINT("enter", ("tables: %p mode_flags: 0x%02x", tables, mode_flags));
@ -640,6 +665,12 @@ int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags)
(*table_ptr)->s->db,
(*table_ptr)->s->table_name,
(*table_ptr)->alias));
/* The first time it is required, lock for close_thread_table(). */
if (! did_lock && ! is_locked)
{
VOID(pthread_mutex_lock(&LOCK_open));
did_lock= TRUE;
}
mysql_ha_flush_table(thd, table_ptr, mode_flags);
continue;
}
@ -658,6 +689,12 @@ int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags)
if ((mode_flags & MYSQL_HA_FLUSH_ALL) ||
((*table_ptr)->s->version != refresh_version))
{
/* The first time it is required, lock for close_thread_table(). */
if (! did_lock && ! is_locked)
{
VOID(pthread_mutex_lock(&LOCK_open));
did_lock= TRUE;
}
mysql_ha_flush_table(thd, table_ptr, mode_flags);
continue;
}
@ -665,6 +702,10 @@ int mysql_ha_flush(THD *thd, TABLE_LIST *tables, uint mode_flags)
}
}
/* Release the lock if it was taken by this function. */
if (did_lock)
VOID(pthread_mutex_unlock(&LOCK_open));
DBUG_RETURN(0);
}
@ -696,8 +737,8 @@ static int mysql_ha_flush_table(THD *thd, TABLE **table_ptr, uint mode_flags)
table->alias, mode_flags));
if ((hash_tables= (TABLE_LIST*) hash_search(&thd->handler_tables_hash,
(byte*) (*table_ptr)->alias,
strlen((*table_ptr)->alias) + 1)))
(byte*) table->alias,
strlen(table->alias) + 1)))
{
if (! (mode_flags & MYSQL_HA_REOPEN_ON_USAGE))
{
@ -712,6 +753,7 @@ static int mysql_ha_flush_table(THD *thd, TABLE **table_ptr, uint mode_flags)
}
(*table_ptr)->file->ha_index_or_rnd_end();
safe_mutex_assert_owner(&LOCK_open);
if (close_thread_table(thd, table_ptr))
{
/* Tell threads waiting for refresh that something has happened */