Commit dd729057 authored by unknown's avatar unknown
Browse files

BUG#20389: Crash when using index scan in reverse order 


mysql-test/r/partition_order.result:
  Changed a test case to handle ordered index scan reverse order as well
mysql-test/t/partition_order.test:
  Changed a test case to handle ordered index scan reverse order as well
sql/ha_myisam.cc:
  More debug info
sql/ha_partition.cc:
  Introduced partition_index_read_last to ensure we use index_read_last in those
  cases towards underlying handler.
  Ensured that index_read with HA_READ_PREFIX_LAST, HA_READ_PREFIX_LAST_OR_PREV and
  HA_READ_BEFORE_KEY uses ordered index scan in reverse order.
sql/ha_partition.h:
  Introduced partition_index_read_last to ensure we use index_read_last in those
  cases towards underlying handler.
  Ensured that index_read with HA_READ_PREFIX_LAST, HA_READ_PREFIX_LAST_OR_PREV and
  HA_READ_BEFORE_KEY uses ordered index scan in reverse order.
parent 16c54768

mysql-test/r/partition_order.result

+54 −2
Original line number Diff line number Diff line
@@ -718,7 +718,11 @@ partitions 2 
partition x2 values less than (100));

INSERT into t1 values (1, 1);

INSERT into t1 values (5, NULL);

INSERT into t1 values (2, 5);

INSERT into t1 values (2, 4);

INSERT into t1 values (3, 3);

INSERT into t1 values (4, 5);

INSERT into t1 values (7, 1);

INSERT into t1 values (6, 6);

INSERT into t1 values (30, 4);

INSERT into t1 values (35, 2);

INSERT into t1 values (40, NULL);
@@ -727,7 +731,55 @@ a b 
5	NULL

40	NULL

1	1

7	1

35	2

3	3

2	4

30	4

2	5

4	5

6	6

select * from t1 force index (b) where b < 10 ORDER BY b;

a	b

1	1

7	1

35	2

3	3

2	4

30	4

4	5

6	6

select * from t1 force index (b) where b < 10 ORDER BY b DESC;

a	b

6	6

4	5

2	4

30	4

3	3

35	2

7	1

1	1

drop table t1;

create table t1 (a int not null, b int, c varchar(20), key (a,b,c))

partition by range (b)

(partition p0 values less than (5),

partition p1 values less than (10));

INSERT into t1 values (1,1,'1'),(2,2,'2'),(1,3,'3'),(2,4,'4'),(1,5,'5');

INSERT into t1 values (2,6,'6'),(1,7,'7'),(2,8,'8'),(1,9,'9');

INSERT into t1 values (1, NULL, NULL), (2, NULL, '10');

select * from t1 where a = 1 order by a desc, b desc;

a	b	c

1	9	9

1	7	7

1	5	5

1	3	3

1	1	1

1	NULL	NULL

select * from t1 where a = 1 order by b desc;

a	b	c

1	9	9

1	7	7

1	5	5

1	3	3

1	1	1

1	NULL	NULL

drop table t1;

mysql-test/t/partition_order.test

+17 −1
Original line number Diff line number Diff line
@@ -818,11 +818,27 @@ partitions 2 
# Insert a couple of tuples

INSERT into t1 values (1, 1);

INSERT into t1 values (5, NULL);

INSERT into t1 values (2, 5);

INSERT into t1 values (2, 4);

INSERT into t1 values (3, 3);

INSERT into t1 values (4, 5);

INSERT into t1 values (7, 1);

INSERT into t1 values (6, 6);

INSERT into t1 values (30, 4);

INSERT into t1 values (35, 2);

INSERT into t1 values (40, NULL);



select * from t1 force index (b) where b < 10 OR b IS NULL order by b;



select * from t1 force index (b) where b < 10 ORDER BY b;

select * from t1 force index (b) where b < 10 ORDER BY b DESC;

drop table t1;



create table t1 (a int not null, b int, c varchar(20), key (a,b,c))

partition by range (b)

(partition p0 values less than (5),

 partition p1 values less than (10));

INSERT into t1 values (1,1,'1'),(2,2,'2'),(1,3,'3'),(2,4,'4'),(1,5,'5');

INSERT into t1 values (2,6,'6'),(1,7,'7'),(2,8,'8'),(1,9,'9');

INSERT into t1 values (1, NULL, NULL), (2, NULL, '10');

select * from t1 where a = 1 order by a desc, b desc;

select * from t1 where a = 1 order by b desc;

drop table t1;

sql/ha_myisam.cc

+2 −1
Original line number Diff line number Diff line
@@ -1202,12 +1202,13 @@ int ha_myisam::index_read_idx(byte * buf, uint index, const byte * key, 


int ha_myisam::index_read_last(byte * buf, const byte * key, uint key_len)

{

  DBUG_ENTER("ha_myisam::index_read_last");

  DBUG_ASSERT(inited==INDEX);

  statistic_increment(table->in_use->status_var.ha_read_key_count,

		      &LOCK_status);

  int error=mi_rkey(file,buf,active_index, key, key_len, HA_READ_PREFIX_LAST);

  table->status=error ? STATUS_NOT_FOUND: 0;

  return error;

  DBUG_RETURN(error);

}



int ha_myisam::index_next(byte * buf)

sql/ha_partition.cc

+22 −8
Original line number Diff line number Diff line
@@ -3265,6 +3265,7 @@ int ha_partition::index_read(byte * buf, const byte * key, 
  DBUG_ENTER("ha_partition::index_read");



  end_range= 0;

  m_index_scan_type= partition_index_read;

  DBUG_RETURN(common_index_read(buf, key, key_len, find_flag));

}
@@ -3282,18 +3283,24 @@ int ha_partition::common_index_read(byte *buf, const byte *key, uint key_len, 
				    enum ha_rkey_function find_flag)

{

  int error;

  bool reverse_order= FALSE;

  DBUG_ENTER("ha_partition::common_index_read");



  memcpy((void*)m_start_key.key, key, key_len);

  m_start_key.length= key_len;

  m_start_key.flag= find_flag;

  m_index_scan_type= partition_index_read;



  if ((error= partition_scan_set_up(buf, TRUE)))

  {

    DBUG_RETURN(error);

  }



  if (find_flag == HA_READ_PREFIX_LAST ||

      find_flag == HA_READ_PREFIX_LAST_OR_PREV ||

      find_flag == HA_READ_BEFORE_KEY)

  {

    reverse_order= TRUE;

    m_ordered_scan_ongoing= TRUE;

  }

  if (!m_ordered_scan_ongoing ||

      (find_flag == HA_READ_KEY_EXACT &&

       (key_len >= m_curr_key_info->key_length ||
@@ -3319,7 +3326,7 @@ int ha_partition::common_index_read(byte *buf, const byte *key, uint key_len, 
      In all other cases we will use the ordered index scan. This will use

      the partition set created by the get_partition_set method.

    */

    error= handle_ordered_index_scan(buf);

    error= handle_ordered_index_scan(buf, reverse_order);

  }

  DBUG_RETURN(error);

}
@@ -3403,7 +3410,7 @@ int ha_partition::common_first_last(byte *buf) 
  if (!m_ordered_scan_ongoing &&

      m_index_scan_type != partition_index_last)

    return handle_unordered_scan_next_partition(buf);

  return handle_ordered_index_scan(buf);

  return handle_ordered_index_scan(buf, FALSE);

}
@@ -3457,7 +3464,9 @@ int ha_partition::index_read_last(byte *buf, const byte *key, uint keylen) 
  DBUG_ENTER("ha_partition::index_read_last");



  m_ordered= TRUE;				// Safety measure

  DBUG_RETURN(index_read(buf, key, keylen, HA_READ_PREFIX_LAST));

  end_range= 0;

  m_index_scan_type= partition_index_read_last;

  DBUG_RETURN(common_index_read(buf, key, keylen, HA_READ_PREFIX_LAST));

}
@@ -3597,6 +3606,7 @@ int ha_partition::read_range_first(const key_range *start_key, 
  }

  else

  {

    m_index_scan_type= partition_index_read;

    error= common_index_read(m_rec0,

			     start_key->key,

			     start_key->length, start_key->flag);
@@ -3855,12 +3865,11 @@ int ha_partition::handle_unordered_scan_next_partition(byte * buf) 
    entries.

*/



int ha_partition::handle_ordered_index_scan(byte *buf)

int ha_partition::handle_ordered_index_scan(byte *buf, bool reverse_order)

{

  uint i;

  uint j= 0;

  bool found= FALSE;

  bool reverse_order= FALSE;

  DBUG_ENTER("ha_partition::handle_ordered_index_scan");



  m_top_entry= NO_CURRENT_PART_ID;
@@ -3881,7 +3890,6 @@ int ha_partition::handle_ordered_index_scan(byte *buf) 
                              m_start_key.key,

                              m_start_key.length,

                              m_start_key.flag);

      reverse_order= FALSE;

      break;

    case partition_index_first:

      error= file->index_first(rec_buf_ptr);
@@ -3891,6 +3899,12 @@ int ha_partition::handle_ordered_index_scan(byte *buf) 
      error= file->index_last(rec_buf_ptr);

      reverse_order= TRUE;

      break;

    case partition_index_read_last:

      error= file->index_read_last(rec_buf_ptr,

                                   m_start_key.key,

                                   m_start_key.length);

      reverse_order= TRUE;

      break;

    default:

      DBUG_ASSERT(FALSE);

      DBUG_RETURN(HA_ERR_END_OF_FILE);

sql/ha_partition.h

+3 −2
Original line number Diff line number Diff line
@@ -46,7 +46,8 @@ class ha_partition :public handler 
    partition_index_read= 0,

    partition_index_first= 1,

    partition_index_last= 2,

    partition_no_index_scan= 3

    partition_index_read_last= 3,

    partition_no_index_scan= 4

  };

  /* Data for the partition handler */

  int  m_mode;                          // Open mode
@@ -429,7 +430,7 @@ class ha_partition :public handler 
      return (queue_buf(part_id) +

              PARTITION_BYTES_IN_POS);

    }

  int handle_ordered_index_scan(byte * buf);

  int handle_ordered_index_scan(byte * buf, bool reverse_order);

  int handle_ordered_next(byte * buf, bool next_same);

  int handle_ordered_prev(byte * buf);

  void return_top_record(byte * buf);