Commit 13985521 authored by unknown's avatar unknown
Browse files

InnoDB: limit the recursion depth for ON (UPDATE|DELETE) CASCADE 

(Bug #4446)


innobase/row/row0ins.c:
  row_ins_foreign_check_on_constraint(): limit recursion for UPDATE too
mysql-test/r/innodb.result:
  Add test for recursion depth limit
mysql-test/t/innodb.test:
  Add test for recursion depth limit
parent 9e6f6198

innobase/row/row0ins.c

+65 −13
Original line number Diff line number Diff line
@@ -370,6 +370,32 @@ row_ins_cascade_ancestor_updates_table( 
	return(FALSE);

}

	

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

Returns the number of ancestor UPDATE or DELETE nodes of a

cascaded update/delete node. */

static

ulint

row_ins_cascade_n_ancestors(

/*========================*/

				/* out: number of ancestors */

	que_node_t*	node)	/* in: node in a query graph */

{

	que_node_t*	parent;

	ulint		n_ancestors = 0;



	parent = que_node_get_parent(node);

	

	while (que_node_get_type(parent) == QUE_NODE_UPDATE) {

		n_ancestors++;



		parent = que_node_get_parent(parent);



		ut_a(parent);

	}



	return(n_ancestors);

}

	

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

Calculates the update vector node->cascade->update for a child table in

a cascaded update. */
@@ -615,6 +641,34 @@ row_ins_foreign_report_add_err( 
	mutex_exit(&dict_foreign_err_mutex);

}



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

Invalidate the query cache for the given table. */

static

void

row_ins_invalidate_query_cache(

/*===========================*/

	que_thr_t*	thr,		/* in: query thread whose run_node

					is an update node */

	const char*	name)		/* in: table name prefixed with

					database name and a '/' character */

{

	char*	buf;

	char*	ptr;

	ulint	len = strlen(name) + 1;



	buf = mem_strdupl(name, len);



	ptr = strchr(buf, '/');

	ut_a(ptr);

	*ptr = '\0';



	/* We call a function in ha_innodb.cc */

#ifndef UNIV_HOTBACKUP

	innobase_invalidate_query_cache(thr_get_trx(thr), buf, len);

#endif

	mem_free(buf);

}



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

Perform referential actions or checks when a parent row is deleted or updated

and the constraint had an ON DELETE or ON UPDATE condition which was not
@@ -650,26 +704,14 @@ row_ins_foreign_check_on_constraint( 
	ulint		n_to_update;

	ulint		err;

	ulint		i;

	char*		ptr;

	char		table_name_buf[1000];

	

	ut_a(thr && foreign && pcur && mtr);



	/* Since we are going to delete or update a row, we have to invalidate

	the MySQL query cache for table */



	ut_a(ut_strlen(table->name) < 998);

	strcpy(table_name_buf, table->name);

	row_ins_invalidate_query_cache(thr, table->name);



	ptr = strchr(table_name_buf, '/');

	ut_a(ptr);

	*ptr = '\0';

	

	/* We call a function in ha_innodb.cc */

#ifndef UNIV_HOTBACKUP

	innobase_invalidate_query_cache(thr_get_trx(thr), table_name_buf,

						ut_strlen(table->name) + 1);

#endif

	node = thr->run_node;



	if (node->is_delete && 0 == (foreign->type &
@@ -756,6 +798,16 @@ row_ins_foreign_check_on_constraint( 
		goto nonstandard_exit_func;

	}



	if (row_ins_cascade_n_ancestors(cascade) >= 15) {

		err = DB_ROW_IS_REFERENCED;



		row_ins_foreign_report_err(

(char*)"Trying a too deep cascaded delete or update\n",

			thr, foreign, btr_pcur_get_rec(pcur), entry);



		goto nonstandard_exit_func;

	}



	index = btr_pcur_get_btr_cur(pcur)->index;



	ut_a(index == foreign->foreign_index);

mysql-test/r/innodb.result

+12 −0
Original line number Diff line number Diff line
@@ -1259,3 +1259,15 @@ Cannot delete or update a parent row: a foreign key constraint fails 
update t3 set  t3.id=7  where t1.id =1 and t2.id = t1.id and t3.id = t2.id;

Unknown table 't1' in where clause

drop table t3,t2,t1;

create table t1(

id int primary key,

pid int,

index(pid),

foreign key(pid) references t1(id) on delete cascade) type=innodb;

insert into t1 values(0,0),(1,0),(2,1),(3,2),(4,3),(5,4),(6,5),(7,6),

(8,7),(9,8),(10,9),(11,10),(12,11),(13,12),(14,13),(15,14);

delete from t1 where id=0;

Cannot delete or update a parent row: a foreign key constraint fails

delete from t1 where id=15;

delete from t1 where id=0;

drop table t1;

mysql-test/t/innodb.test

+14 −0
Original line number Diff line number Diff line
@@ -896,3 +896,17 @@ update t1,t2,t3 set t3.id=5, t2.id=6, t1.id=7 where t1.id =1 and t2.id = t1.id 
--error 1109

update t3 set  t3.id=7  where t1.id =1 and t2.id = t1.id and t3.id = t2.id;

drop table t3,t2,t1;



create table t1(

	id int primary key,

	pid int,

	index(pid),

	foreign key(pid) references t1(id) on delete cascade) type=innodb;

insert into t1 values(0,0),(1,0),(2,1),(3,2),(4,3),(5,4),(6,5),(7,6),

	(8,7),(9,8),(10,9),(11,10),(12,11),(13,12),(14,13),(15,14);

-- error 1217

delete from t1 where id=0;

delete from t1 where id=15;

delete from t1 where id=0;



drop table t1;