mariadb/storage/myisammrg/ha_myisammrg.h
Konstantin Osipov 463dcbb51c Backport of revid 2617.69.21, 2617.69.22, 2617.29.23:
----------------------------------------------------------
revno: 2617.69.21
committer: Konstantin Osipov <kostja@sun.com>
branch nick: 5.4-4284-1-assert
timestamp: Thu 2009-08-13 20:13:55 +0400
message:
  A fix and a test case for Bug#46610 "MySQL 5.4.4: MyISAM MRG engine crash
  on auto-repair of child".
  Also fixes Bug#42862 "Crash on failed attempt to open a children of a
  merge table".

  MERGE engine needs to extend the global table list
  with TABLE_LIST elements for child tables,
  so that they are opened and locked.
  Previously these table list elements were allocated
  in memory of ha_myisammrg object (MERGE engine handler).
  That would lead to access to freed memory in
  recover_from_failed_open_table_attempt(), which would
  try to recover a MERGE table child (MyISAM table)
  and use for that TABLE_LIST of that child.
  But by the time recover_from_failed_open_table_attempt()
  is invoked, ha_myisammrg object that owns this
  TABLE_LIST may be destroyed, and thus TABLE_LIST
  memory freed.

  The fix is to ensure that TABLE_LIST elements
  that are added to the global table list (lex->query_tables)
  are always allocated in thd->mem_root, which is not
  destroyed until end of execution.

  If previously TABLE_LIST elements were allocated
  at ha_myisammrg::open() (i.e. when the TABLE
  object was created and added to the table cache),
  now they are allocated in ha_myisammrg::add_chidlren_list()
  (i.e. right after "open" of the merge parent in
  open_tables()).
  We still create a list of children names
  at ha_myisammrg::open() to use as a basis
  for creation of TABLE_LISTs, that allows
  to avoid reading the merge handler data
  file on every execution.


mysql-test/r/merge_recover.result:
  Test results for Bug#46610.
mysql-test/t/merge_recover-master.opt:
  Option file for Bug#46610 test (need a new test because
  of that option, which is not tested anywhere else).
mysql-test/t/merge_recover.test:
  Add a test case for Bug#46610.
sql/table.h:
  MERGE child child_def_version is now moved from TABLE_LIST
  to MERGE engine specific data structure.
storage/myisammrg/ha_myisammrg.cc:
  Introduce an auxiliary structure to keep MERGE child name
  and definition version. A list of Mrg_child_def is created
  in ha_myisammrg::open() and reused in ha_myisammrg::add_children_list().
2009-12-08 16:57:25 +03:00

150 lines
5.4 KiB
C++

/* Copyright (C) 2000-2006 MySQL AB
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifdef USE_PRAGMA_INTERFACE
#pragma interface /* gcc class implementation */
#endif
/* class for the the myisam merge handler */
#include <myisammrg.h>
/**
Represents one name of a MERGE child.
@todo: Add MYRG_SHARE and store chlidren names in the
share.
*/
class Mrg_child_def: public Sql_alloc
{
/* Remembered MERGE child def version. See top comment in ha_myisammrg.cc */
enum_table_ref_type m_child_table_ref_type;
ulong m_child_def_version;
public:
LEX_STRING db;
LEX_STRING name;
/* Access MERGE child def version. See top comment in ha_myisammrg.cc */
inline enum_table_ref_type get_child_table_ref_type()
{
return m_child_table_ref_type;
}
inline ulong get_child_def_version()
{
return m_child_def_version;
}
inline void set_child_def_version(enum_table_ref_type child_table_ref_type,
ulong version)
{
m_child_table_ref_type= child_table_ref_type;
m_child_def_version= version;
}
Mrg_child_def(char *db_arg, size_t db_len_arg,
char *table_name_arg, size_t table_name_len_arg)
{
db.str= db_arg;
db.length= db_len_arg;
name.str= table_name_arg;
name.length= table_name_len_arg;
m_child_def_version= ~0UL;
m_child_table_ref_type= TABLE_REF_NULL;
}
};
class ha_myisammrg: public handler
{
MYRG_INFO *file;
my_bool is_cloned; /* This instance has been cloned */
public:
MEM_ROOT children_mem_root; /* mem root for children list */
List<Mrg_child_def> child_def_list;
TABLE_LIST *children_l; /* children list */
TABLE_LIST **children_last_l; /* children list end */
uint test_if_locked; /* flags from ::open() */
ha_myisammrg(handlerton *hton, TABLE_SHARE *table_arg);
~ha_myisammrg();
const char *table_type() const { return "MRG_MyISAM"; }
const char **bas_ext() const;
const char *index_type(uint key_number);
ulonglong table_flags() const
{
return (HA_REC_NOT_IN_SEQ | HA_AUTO_PART_KEY | HA_NO_TRANSACTIONS |
HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE |
HA_NULL_IN_KEY | HA_CAN_INDEX_BLOBS | HA_FILE_BASED |
HA_ANY_INDEX_MAY_BE_UNIQUE | HA_CAN_BIT_FIELD |
HA_HAS_RECORDS |
HA_NO_COPY_ON_ALTER |
HA_DUPLICATE_POS);
}
ulong index_flags(uint inx, uint part, bool all_parts) const
{
return ((table_share->key_info[inx].algorithm == HA_KEY_ALG_FULLTEXT) ?
0 : HA_READ_NEXT | HA_READ_PREV | HA_READ_RANGE |
HA_READ_ORDER | HA_KEYREAD_ONLY);
}
uint max_supported_keys() const { return MI_MAX_KEY; }
uint max_supported_key_length() const { return MI_MAX_KEY_LENGTH; }
uint max_supported_key_part_length() const { return MI_MAX_KEY_LENGTH; }
double scan_time()
{ return ulonglong2double(stats.data_file_length) / IO_SIZE + file->tables; }
int open(const char *name, int mode, uint test_if_locked);
int add_children_list(void);
int attach_children(void);
int detach_children(void);
virtual handler *clone(MEM_ROOT *mem_root);
int close(void);
int write_row(uchar * buf);
int update_row(const uchar * old_data, uchar * new_data);
int delete_row(const uchar * buf);
int index_read_map(uchar *buf, const uchar *key, key_part_map keypart_map,
enum ha_rkey_function find_flag);
int index_read_idx_map(uchar *buf, uint index, const uchar *key,
key_part_map keypart_map,
enum ha_rkey_function find_flag);
int index_read_last_map(uchar *buf, const uchar *key, key_part_map keypart_map);
int index_next(uchar * buf);
int index_prev(uchar * buf);
int index_first(uchar * buf);
int index_last(uchar * buf);
int index_next_same(uchar *buf, const uchar *key, uint keylen);
int rnd_init(bool scan);
int rnd_next(uchar *buf);
int rnd_pos(uchar * buf, uchar *pos);
void position(const uchar *record);
ha_rows records_in_range(uint inx, key_range *min_key, key_range *max_key);
int info(uint);
int reset(void);
int extra(enum ha_extra_function operation);
int extra_opt(enum ha_extra_function operation, ulong cache_size);
int external_lock(THD *thd, int lock_type);
uint lock_count(void) const;
int create(const char *name, TABLE *form, HA_CREATE_INFO *create_info);
THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
enum thr_lock_type lock_type);
void update_create_info(HA_CREATE_INFO *create_info);
void append_create_info(String *packet);
MYRG_INFO *myrg_info() { return file; }
TABLE *table_ptr() { return table; }
bool check_if_incompatible_data(HA_CREATE_INFO *info, uint table_changes);
int check(THD* thd, HA_CHECK_OPT* check_opt);
ha_rows records();
};