Commit 26f75ffc authored by unknown's avatar unknown
Browse files

Bug#8306 - TRUNCATE leads to index corruption 

Added a check, if the table, which we are going to create, is open.
This can happen if a MERGE mapped table is TRUNCATEd.


myisam/mi_open.c:
  Bug#8306 - TRUNCATE leads to index corruption
  Made test_if_reopen() globally available.
myisam/myisamdef.h:
  Bug#8306 - TRUNCATE leads to index corruption
  Declared test_if_reopen() as globally available.
mysql-test/r/myisam.result:
  Bug#8306 - TRUNCATE leads to index corruption
  The test result.
mysql-test/t/myisam.test:
  Bug#8306 - TRUNCATE leads to index corruption
  The test case.
parent 22e0b300

myisam/mi_create.c

+15 −0
Original line number Diff line number Diff line
@@ -533,6 +533,21 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs, 
    create_flag=MY_DELETE_OLD;

  }



  /*

    If a MRG_MyISAM table is in use, the mapped MyISAM tables are open,

    but no entry is made in the table cache for them.

    A TRUNCATE command checks for the table in the cache only and could

    be fooled to believe, the table is not open.

    Pull the emergency brake in this situation. (Bug #8306)

  */

  if (test_if_reopen(filename))

  {

    my_printf_error(0, "MyISAM table '%s' is in use "

                    "(most likely by a MERGE table). Try FLUSH TABLES.",

                    MYF(0), name + dirname_length(name));

    goto err;

  }



  if ((file= my_create_with_symlink(linkname_ptr,

				    filename,

				    0, O_RDWR | O_TRUNC,

myisam/mi_open.c

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ if (pos > end_pos) \ 
** In MySQL the server will handle version issues.

******************************************************************************/



static MI_INFO *test_if_reopen(char *filename)

MI_INFO *test_if_reopen(char *filename)

{

  LIST *pos;

myisam/myisamdef.h

+1 −0
Original line number Diff line number Diff line
@@ -705,6 +705,7 @@ void mi_copy_status(void* to,void *from); 
my_bool mi_check_status(void* param);

void mi_disable_non_unique_index(MI_INFO *info, ha_rows rows);



extern MI_INFO *test_if_reopen(char *filename);

my_bool check_table_is_closed(const char *name, const char *where);

int mi_open_datafile(MI_INFO *info, MYISAM_SHARE *share, File file_to_dup);

int mi_open_keyfile(MYISAM_SHARE *share);

mysql-test/r/myisam.result

+18 −0
Original line number Diff line number Diff line
@@ -555,3 +555,21 @@ select count(*) from t1 where a is null; 
count(*)

2

drop table t1;

create table t1 (c1 int, index(c1));

create table t2 (c1 int, index(c1)) engine=merge union=(t1);

insert into t1 values (1);

flush tables;

select * from t2;

c1

1

flush tables;

truncate table t1;

insert into t1 values (1);

flush tables;

select * from t2;

c1

1

truncate table t1;

ERROR HY000: MyISAM table 't1' is in use (most likely by a MERGE table). Try FLUSH TABLES.

insert into t1 values (1);

drop table t1,t2;

mysql-test/t/myisam.test

+26 −0
Original line number Diff line number Diff line
@@ -524,3 +524,29 @@ explain select count(*) from t1 where a is null; 
select count(*) from t1 where a is null;

drop table t1;



#

# Bug #8306: TRUNCATE leads to index corruption 

#

create table t1 (c1 int, index(c1));

create table t2 (c1 int, index(c1)) engine=merge union=(t1);

insert into t1 values (1);

# Close all tables.

flush tables;

# Open t2 and (implicitly) t1.

select * from t2;

# Truncate after flush works (unless another threads reopens t2 in between).

flush tables;

truncate table t1;

insert into t1 values (1);

# Close all tables.

flush tables;

# Open t2 and (implicitly) t1.

select * from t2;

# Truncate t1, wich was not recognized as open without the bugfix.

# Now, it should fail with a table-in-use error message.

--error 1105

truncate table t1;

# The insert used to fail on the crashed table.

insert into t1 values (1);

drop table t1,t2;